BACKGROUND A previous study compared vortexing and Maki techniques for the diagnosis of catheter-related bloodstream infection(CRBSI),and concluded that vortexing was not superior to Maki method.AIM To determine wheth...BACKGROUND A previous study compared vortexing and Maki techniques for the diagnosis of catheter-related bloodstream infection(CRBSI),and concluded that vortexing was not superior to Maki method.AIM To determine whether the combined use of vortexing and Maki techniques provides profitability versus the Maki technique for the diagnosis of catheter tip colonization(CTC)and CRBSI.METHODS Observational and prospective study carried out in an Intensive Care Unit.Patients with suspected catheter-related infection(CRI)and with one central venous catheter for at least 7 days were included.The area under the curve(AUC)of the Maki technique,the vortexing technique and the combination of both techniques for the diagnosis of CTC and CRBSI were compared.RESULTS We included 136 episodes of suspected CRI.We found 21 cases of CTC of which 10 were also CRBSI cases.Of the 21 CTC episodes,18(85.7%)were diagnosed by Maki technique and vortexing technique,3(14.3%)only by the technique of Maki,and none only by technique of vortexing.Of the 10 CRBSI episodes,9(90.0%)were diagnosed by the techniques of Maki and vortexing,1(10.0%)was diagnosed only by the technique of Maki,and none only by the technique of vortexing.We no found differences in the comparison of AUC between the technique of Maki and the combination of Maki and vortexing techniques for the diagnosis of CTC(P=0.99)and CRBSI(P=0.99).CONCLUSION The novel finding of our study was that the combined use of vortexing and Maki techniques did not provide profitability to the technique of Maki alone to CRBSI diagnosis of.展开更多
BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-...BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-acquired infections(HAIs).Studies across various World Health Organization regions have documented a significant incidence of CRAB-related HAIs,with rates as high as 41.7 cases per 1000 patients in ICUs,accounting for 13.6%of all HAIs.These infections pose a doubled mortality risk compared to infections with carbapenem-susceptible Acinetobacter baumannii.A particularly concerning aspect of CRAB colonization is its asymptomatic nature,enabling its transmission through healthcare workers(HCWs)or the NICU environment to vulnerable neonates with developing immune systems.AIM To explore the prevalence of CRAB colonization in NICUs,focusing on neonates,healthcare workers,and the environmental samples,to enhance epidemiological understanding and inform targeted interventions.METHODS We conducted according to PRISMA 2020 checklist guidelines,a comprehensive literature search across multiple databases including MEDLINE(Ovid),EMBASE(Ovid),Global Health(Ovid),Web of Science,and Global Index Me-dicus.Studies were selected based on predetermined criteria,primarily involving neonates,HCWs,and environmental swabs,using culture or molecular methods to detect CRAB colonization.We excluded studies that did not specifically focus on NICUs,were duplicates,or lacked necessary data.The study selection and quality assessment were conducted independently by two reviewers.Data extraction involved collecting comprehensive details about each study.Our statistical analysis used a random-effects model to calculate the pooled prevalence and confidence intervals,stratifying results by regional location.We assessed study heterogeneity using Cochran's Q statistic and I²statistic,with regression tests employed to evaluate potential publication bias.RESULTS We analyzed 737 records from five databases,ultimately including 13 studies from ten countries.For neonates,the pooled prevalence was 4.8%(95%CI:1.1%to 10.5%)with the highest rates observed in South-East Asia(10.5%;95%CI:2.4%to 23.3%).Among HCWs,a single Indian study reported a 3.3%prevalence.Environmental samples showed a prevalence of 2.3%(95%CI:0%to 9.3%),with the highest rates in South-East Asia(10%;95%CI:4.2%to 17.7%).Significant heterogeneity was found across studies,and no publication bias was detected.CONCLUSION This systematic review highlights a significant prevalence of CRAB colonization in neonates across various regions,particularly in South-East Asia,contrasting with lower rates in high-income countries.The study reveals a gap in research on HCWs colonization,with only a single study from India reporting moderate prevalence.Environmental samples indicate moderate levels of CRAB contamination,again higher in South-East Asia.These findings underscore the need for more extensive and focused research on CRAB colonization in NICUs,including exploring the roles of HCWs and the environment in transmission,understanding antimicrobial resistance patterns,and developing effective prevention measures.展开更多
Background As Holstein calves are susceptible to gastrointestinal disorders during the first week of life,understanding how intestinal immune function develops in neonatal calves is important to promote better intesti...Background As Holstein calves are susceptible to gastrointestinal disorders during the first week of life,understanding how intestinal immune function develops in neonatal calves is important to promote better intestinal health.Feeding probiotics in early life may contribute to host intestinal health by facilitating beneficial bacteria colonization and developing intestinal immune function.The objective of this study was to characterize the impact of early life yeast supplementation and growth on colon mucosa-attached bacteria and host immune function.Results Twenty Holstein bull calves received no supplementation(CON)or Saccharomyces cerevisiae boulardii(SCB)from birth to 5 d of life.Colon tissue biopsies were taken within 2 h of life(D0)before the first colostrum feeding and 3 h after the morning feeding at d 5 of age(D5)to analyze mucosa-attached bacteria and colon transcriptome.Metagenome sequencing showed that there was no difference inαandβdiversity of mucosa-attached bacteria between day and treatment,but bacteria related to diarrhea were more abundant in the colon mucosa on D0 compared to D5.In addition,q PCR indicated that the absolute abundance of Escherichia coli(E.coli)decreased in the colon mucosa on D5 compared to D0;however,that of Bifidobacterium,Lactobacillus,and Faecalibacterium prausnitzii,which could competitively exclude E.coli,increased in the colon mucosa on D5 compared to D0.RNA-sequencing showed that there were no differentially expressed genes between CON and SCB,but suggested that pathways related to viral infection such as“Interferon Signaling”were activated in the colon mucosa of D5 compared to D0.Conclusions Growth affected mucosa-attached bacteria and host immune function in the colon mucosa during the first 5 d of life in dairy calves independently of SCB supplementation.During early life,opportunistic pathogens may decrease due to intestinal environmental changes by beneficial bacteria and/or host immune function.Predicted activation of immune function-related pathways may be the result of host immune function development or suggest other antigens in the intestine during early life.Further studies focusing on the other antigens and host immune function in the colon mucosa are required to better understand intestinal immune function development.展开更多
Colonization and development of the gut microbiome are crucial for the growth and health of calves.In this review,we summarized the colonization,beneficial nutrition,immune function of gut microbiota,function of the g...Colonization and development of the gut microbiome are crucial for the growth and health of calves.In this review,we summarized the colonization,beneficial nutrition,immune function of gut microbiota,function of the gut barrier,and the evolution of core microbiota in the gut of calves of different ages.Homeostasis of gut microbiome is beneficial for nutritional and immune system development of calves.Disruption of the gut microbiome leads to digestive diseases in calves,such as diarrhea and intestinal inflammation.Microbiota already exists in the gut of calf fetuses,and the colonization of microbiota continues to change dynamically under the influence of various factors,which include probiotics,diet,age,and genotype.Colonization depends on the interaction between the gut microbiota and the immune system of calves.The abundance and diversity of these commensal microbiota stabilize and play a critical role in the health of calves.展开更多
Sclerotinia stem rot,caused by Sclerotinia sclerotiorum,is a destructive soil-borne disease leading to huge yield loss.We previously reported that Klebsiella variicola FH-1 could degrade atrazine herbicides,and the ve...Sclerotinia stem rot,caused by Sclerotinia sclerotiorum,is a destructive soil-borne disease leading to huge yield loss.We previously reported that Klebsiella variicola FH-1 could degrade atrazine herbicides,and the vegetative growth of atrazine-sensitive crops(i.e.,soybean)was significantly increased in the FH-1-treated soil.Interestingly,we found that FH-1 could promote soybean growth and induce resistance to S.sclerotiorum.In our study,strain FH-1 could grow in a nitrogen-free environment,dissolve inorganic phosphorus and potassium,and produce indoleacetic acid and a siderophore.The results of pot experiments showed that K.variicola FH-1 promoted soybean plant development,substantially improving plant height,fresh weight,and root length,and induced resistance against S.sclerotiorum infection in soybean leaves.The area under the disease progression curve(AUDPC)for treatment with strain FH-1 was significantly lower than the control and was reduced by up to 42.2%within 48 h(P<0.001).Moreover,strain FH-1 rcovered the activities of catalase,superoxide dismutase,peroxidase,phenylalanine ammonia lyase,and polyphenol oxidase,which are involved in plant protection,and reduced malondialdehyde accumulation in the leaves.The mechanism of induction of resistance appeared to be primarily resulted from the enhancement of transcript levels of PR10,PR12,AOS,CHS,and PDF1.2 genes.The colonization of FH-1 on soybean root,determined using CLSM and SEM,revealed that FH-1 colonized soybean root surfaces,root hairs,and exodermis to form biofilms.In summary,K.variicola FH-1 exhibited the biological control potential by inducing resistance in soybean against S.sclerotiorum infection,providing new suggestions for green prevention and control.展开更多
After being ingested and entering the human stomach,Helicobacter pylori(H.pylori)adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain ...After being ingested and entering the human stomach,Helicobacter pylori(H.pylori)adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain more nutrients and escape from the harsher environments of the stomach,leading to acute infection and chronic gastritis,which is the basis of malignant gastric tumors.The endoscopic manifestations and pathological features of H.pylori infection are diverse and vary with the duration of infection.In this review,we describe the endoscopic manifestations of each stage of H.pylori gastritis and then reveal the potential mechanisms of bacterial intragastric colonization and migration from the perspective of endoscopists to provide direction for future research on the effective therapy and management of H.pylori infection.展开更多
Arbuscular mycorrhizal(AM)fungi can form symbiosis with 90%of the vascular plants and play important roles in ecosystem.To realize the AM fungal colonization at different succession stages in saline-alkali land and sc...Arbuscular mycorrhizal(AM)fungi can form symbiosis with 90%of the vascular plants and play important roles in ecosystem.To realize the AM fungal colonization at different succession stages in saline-alkali land and screen AM fungi species with great functions,roots and soil samples were collected from the three succession stages of Songnen saline-alkali grassland.The soil properties and AM fungal colonization were measured,and the fungus distributed extensively in three stages was annotated by sequencing for AML1/AML2 target,subsequently,maize was selected as the host to verify its colonization.The results showed that the soil properties improved with the succession of saline-alkali grassland.The plants’communities of the three stages could be colonized by AM fungi,and the colonization rate of Leymus chinensis(the third stage)ranged from 66.67%to 100%,Puccinellia tenuiflora(the second stage)ranged from 50%to 80%,while the Suaeda glauca(the first stage)was only 35%–60%.Glomeraceae sp1 was identified as the dominant AM fungi species which occurred frequently in the succession of saline-alkali land with the isolation frequency,relative abundance,and importance value of 100%,18.1%,and 59.1%,respectively.The colonization rate of Glomeraceae sp1 in maize ranged from 80%to 87%and similar mycorrhizal characteristics were detected in the roots of P.tenuiflora,S.glauca,and L.chinensis,indicating that Glomeraceae sp1 colonized the samples in the field.The correlation matrix indicated that colonization rate,colonization intensity,and vesicle abundance were closely related to soil conditions most,and they were related significantly to all the soil properties except cellulase activity.Besides,redundancy analysis(RDA)showed that soil properties drove the changes of AM fungal colonization and sporulation.These results will provide theoretical support for realizing the relationship between AM fungal colonization and soil conditions,and also for the exploration of AM fungi species with great functions.展开更多
Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gno...Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gnotobiotically in flask with semi-solid agar medium. Observations were performed with confocal laser scanning microscopy (CLSM) and electron microscopy, respectively, at 8 d and 12 d after inoculation. Confocal laser scanning microscopy showed that A. brasilense Yu62 could penetrate into the cortex tissue, colonizing in the intercellular spaces of the parenchyma cells of the cortex tissue. Transmission and scanning electron microscopy (TEM) showed that the majority of the bacteria colonized on the root surface and only a minority of them resided in the root interior.展开更多
Arbuscular mycorrhizal fungi（AMF） and dark septate endophyte（DSE） colonization were investigated in three different plantation sites（Umdihar,Umsaw and Mawlein） of Meghalaya,northeast India.Isolation and identifi...Arbuscular mycorrhizal fungi（AMF） and dark septate endophyte（DSE） colonization were investigated in three different plantation sites（Umdihar,Umsaw and Mawlein） of Meghalaya,northeast India.Isolation and identification of the AMF spore were conducted to evaluate the AMF diversity and host preference in terms of AMF species distribution and abundance in the plantation sites.Results showed that AMF colonization was significantly higher than dark septate endophyte colonization（p〉0.05）.AMF and DSE colonization had a narrow range of colonization,varying from 50.91%-58.95% and 1.84%-4.11%,respectively.Spore density varied significantly in all the sites（p〉0.05）.Out of 29 species identified from 7 genera,the species from Glomus was found to be highly abundant.Sorenson coefficient（Cs） ranged from 0.35-7.0.Species richness varied from 2.0-2.9 in the sites.Total species richness was significantly correlated with total relative abundance（p=0.001）.The distribution,abundance and principal component analysis plot suggest that Glomus macrocarpum,G.multicaulis,G.constrictum and Acaulospora sp 1 were the most host preferred species which possibly may favour the host with proper nutrient acquisition and growth.展开更多
Helicobacter pylori(H.pylori)colonizes the stomach of humans and causes chronic infection.The majority of bacteria live in the mucus layer overlying the gastric epithelial cells and only a small proportion of bacteria...Helicobacter pylori(H.pylori)colonizes the stomach of humans and causes chronic infection.The majority of bacteria live in the mucus layer overlying the gastric epithelial cells and only a small proportion of bacteria are found interacting with the epithelial cells.The bacteria living in the gastric mucus may act as a reservoir of infection for the underlying cells which is essential for the development of disease.Colonization of gastric mucus is likely to be key to the establishment of chronic infection.How H.pylori manages to colonise and survive in the hostile environment of the human stomach and avoid removal by mucus flow and killing by gastric acid is the subject of this review.We also discuss how bacterial and host factors may together go some way to explaining the susceptibility to colonization and the outcome of infection in different individuals.H.pylori infection of the gastric mucosa has become a paradigm for chronic infection.Understanding of why H.pylori is such a successful pathogen may help us understand how other bacterial species colonise mucosal surfaces and cause disease.展开更多
Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW...Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW)piglets,intrauterine growth restricted(IUGR)piglets have a different intestinal microbiota during their early life,which is related to maternal imprinting on intestinal microbial succession during gestation,at birth and via suckling.Imbalanced allocation of limited nutrients among fetuses during gestation could be one of the main causes for impaired intestinal development and microbiota colonization in neonatal IUGR piglets.In this review,we summarized the potential impact of maternal imprinting on the colonization of the intestinal microbiota in IUGR piglets,including maternal undernutrition,imbalanced allocation of nutrients among fetuses,as well as vertical microbial transmission from mother to offspring during gestation and lactation.At the same time,we give information about the current maternal nutritional strategies(mainly breastfeeding,probiotics and prebiotics)to help colonization of the advantageous intestinal microbiota for IUGR piglets.展开更多
Interactions between plants and soil microorganisms can influence the other interactions in which plants participate, including interactions with herbivores. Many fungi, including arbuscular mycorrhizal fungi(AMF), fo...Interactions between plants and soil microorganisms can influence the other interactions in which plants participate, including interactions with herbivores. Many fungi, including arbuscular mycorrhizal fungi(AMF), form symbiotic relationships with the roots they inhabit, and potentially alter defense against pests. The objective of this study was to document the extent of root colonization by AMF on non-flooded rice plants grown under conditions typical of commercial fields. We hypothesized that AMF naturally colonized rice plants in different rice producing field locations. Rice plant samples were collected from areas across the southern United States, including Texas, Mississippi, Arkansas and two research stations in Louisiana. We quantified the amount of AMF colonization in insecticide-free rice plants over three consecutive years(2014–2016). The results revealed natural colonization of AMF in all rice producing areas. In all the three years of survey, rice-AMF associations were the greatest in Arkansas followed by Mississippi and Texas. This research will help draw attention to natural colonization of AMF in rice producing areas that can impact future rice research and production by facilitating agricultural exploitation of the symbiosis.展开更多
Bacillus cereus NJSZ-13,an endophytic bacterium with nematicidal activity,was isolated from stems of healthy Pinus elliottii Engelm.Colonization of P.massoniana Lamb.by endophytic B.cereus was studied using scanning e...Bacillus cereus NJSZ-13,an endophytic bacterium with nematicidal activity,was isolated from stems of healthy Pinus elliottii Engelm.Colonization of P.massoniana Lamb.by endophytic B.cereus was studied using scanning electron microscopy and confocal laser scanning microscopy.After the plasmid p GFP78 containing the green fluorescent protein(GFP)gene was transformed into the NJSZ-13 strain,the NJSZ-13:gfp showed the same nematicidal activity and growth curve as the wild-type strain,and the plasmid p GFP78 was stably maintained in strain NJSZ-13 for at least 96 h of bacterial cultivation on medium without antibiotics.After inoculation into Masson pine roots,colonization of the NJSZ-13:gfp strain in plant roots and stems was visualized using confocal laser scanning and the strain was enumerated in inoculated roots and stems.These results suggest that NJSZ-13:gfp is an efficient colonizer of Masson pine and can transfer vertically from roots to stems.展开更多
AIM： To characterize the role of flgK and its protein product in Hpylori colonization. METHODS： The PCR cloning method identified the flgK gene. An isogenic flgK mutant was constructed by gene replacement and confir...AIM： To characterize the role of flgK and its protein product in Hpylori colonization. METHODS： The PCR cloning method identified the flgK gene. An isogenic flgK mutant was constructed by gene replacement and confirmed by Southern blot analysis and PCR analysis. The recombinant FlgK protein （r-FlgK） was purified. Electron microscopy （EM） was applied to demonstrate the flagella of H pylori. An in vitro motility test was assessed in semisolid medium. The densities of H pylori colonization with either the wild-type strain or its flgK mutant were compared among BALB/c mice with or without pre-immunization with r-FlgK. The serological responses to r-FlgK were analyzed for 70 clinical patients with different densities of H pylori colonization. RESULTS： From a duodenal ulcer strain, the flgK gene was cloned and it contained 1821 bp, with a 95.7% identity to the published sequences. No flagella were observed under EM for the mutant strain, which had a loss of motility. Hpylori density was lower in the BALB/c mice inoculated by the mutant or with pre-immunization with r-FlgK compared to unimmunized mice or mice inoculated by the wild-type strain （P 〈 0.05）. In the H pylori-infected patients, the serological responses to r-FlgK were uniformly low in titer.CONCLUSION： FlgK encoded by flgK is important for flagella formation and H pylori motility. Deficiency in FlgK or an enhanced serological response to r-FlgK can interfere with Hpylori colonization. FlgK of Hpylori could be a novel target for vaccination.展开更多
The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the us...The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis.展开更多
The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse（n=80） by using a punch biops...The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse（n=80） by using a punch biopsy.The mice were assigned randomly into two groups,with 40 animals in each group：a non-thermal plasma group in which the mice were treated with the non-thermal plasma;a control group in which the mice were left to heal naturally.Wound healing was evaluated on postoperative days（POD） 4,7,10 and 14（n=5 per group in each POD） by percentage of wound closure.The mice was euthanized on POD 1,4,7,10,14,21,28 and 35（n=1 in each POD）.The wounds were removed,routinely fixed,paraffin-embedded,sectioned and HE-stained.A modified scoring system was used to evaluate the wounds.The results showed that acute inflammation peaked on POD 4 in non-thermal plasma group,earlier than in control group in which acute inflammation reached a peak on POD 7,and the acute inflammation scores were much lower in non-thermal group than in control group on POD 7（P0.05）.The amount of granular tissue was greater on POD 4 and 7 in non-thermal group than in control group（P0.05）.The re-epithelialization score and the neovasularization score were increased significantly in non-thermal group when compared with control group on POD 7 and 10（P0.05 for all）.The count of bacterial colonies was 103 CFU/mL on POD 4 and 20 CFU/mL on POD 7,significantly lower than that in control group（109 CFU/mL on POD 4 and 1012 CFU/mL on the POD 7）（P0.05）.It was suggested that the non-thermal plasma facilitates the wound healing by suppressing bacterial colo-nization.展开更多
Fragmentation and loss of habitats due to natural disasters, like earthquakes and earthquaketriggered debris flows are existing threats to the long- term survival of the giant panda （Ailuropoda melanoleuca）. To bett...Fragmentation and loss of habitats due to natural disasters, like earthquakes and earthquaketriggered debris flows are existing threats to the long- term survival of the giant panda （Ailuropoda melanoleuca）. To better understand natural recovery processes of the damaged habitat, field investigation and laboratory analysis were used to analyze relationships between plant colonization and soil characteristics in an over 3o-year natural recovery of a damaged giant panda habitat in a debris flow gully after the 1976 Songpan-Pingwu earthquake in Sichuan Province, China. Four different damaged sites were selected that located at the center of the gully （center）, on a flat alluvial fan （fan）, in a side slope of the gully （slope）, and at the ecotone between the gully and native forest （ecotone）. Vegetation characteristics, soil physicochemical properties, and microbial biomass in the different sites and soil depths were measured. After the natural recovery, the soil fertility, water retention, and microbial biomass were highest at ecotone, followed by fan, slope, and center. Only a few perennial herbs colonized at center; shrubs started to invade at fan and slope, and the native trees dominated the community of ecotone. Furthermore, Fargesia spathacea （food for the giant panda） started to be re-established at ecotone, and the community characteristic of ecotone recovered similarly to the native habitat. These results suggested that improving the soil fertility, water retaining capacity and microbial biomass is fundamental to the plant colonization, particular for F. spathacea＇s re- establishment in a damaged giant panda habitat.展开更多
The fungus U. virens is the causal agent of rice false smut disease. The green fluorescent protein (GFP) was used to mark this fungus in order to visualize and analyze the colonization and infection processes in vivo....The fungus U. virens is the causal agent of rice false smut disease. The green fluorescent protein (GFP) was used to mark this fungus in order to visualize and analyze the colonization and infection processes in vivo. Using epifluorescence microscopy colonization and infection on rice roots were visualized in vivo. After inoculation for 2 to 15 d, it was observed that the conidia and their germ-tubes had penetrated into epidermis of young roots. The hyphae were found inside the root xylem 18 d after inoculation. Generally, the transformed fungus colonized the rhizosphere, the cortex as well as the vascular tissues with symptoms of root necrosis observed. The results of this work show that U. virens colonize not only rice panicles but also the roots.展开更多
To understand arbuscular mycorrhizal(AM)fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances,Iris lactea,which grows in the Songnen saline-alkaline grassland with a high o...To understand arbuscular mycorrhizal(AM)fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances,Iris lactea,which grows in the Songnen saline-alkaline grassland with a high ornamental value,was selected as the experimental material,and the colonization characteristics of its roots and the AM fungal diversity in its rhizosphere were explored.The results of the observations and calculations of mycorrhizae from ten different samples showed that AM fungi colonized the roots of I.lactea and formed Arum-type mycorrhizal structures.There was a significant correlation between soil spore density and pH value,while the colonization rate showed a fluctuating trend with increasing pH values.The observed colonization intensities were of Levels II(1%–10%)or III(11%–50%),and the vesicle abundances were of grades A2 or A3 among different sites.AM fungi produced a large number of mycelia and vesicles in the roots of I.lactea after colonization.Thirty-seven species belonging to 15 genera of AM fungi were isolated from the rhizosphere of I.lactea and identified by morphological identification.Funneliformis and Glomus were the dominant genera,accounting for 21.79%and 20.85%of the total number,respectively.F.mosseae and Rhizophagus intraradices were isolated in all samples with importance values of 58.62 and 51.19,respectively.These results are expected to provide a theoretical basis for the analysis of the salt tolerance mechanism of I.lactea and for the discovery,exploration and further screening of AM fungal resources with salinity tolerances in saline-alkaline soils.展开更多
Horses, like all animals, are born without the symbiotic microbes that occupy the gastrointestinal tracts of mature animals. As grazing animals, horses rely on these microbes to fully utilize the grasses and other cel...Horses, like all animals, are born without the symbiotic microbes that occupy the gastrointestinal tracts of mature animals. As grazing animals, horses rely on these microbes to fully utilize the grasses and other cellulosic feeds that they consume. Thus, colonization of the foal's gastrointestinal tract must occur between birth and weaning. The feces of nine mare and foal pairs were sampled from the day of parturition until 12 weeks of age, and the samples were analyzed by polymerase chain reaction amplification of the bacterial 16S rRNA gene and denaturing gradient gel electrophoresis (PCR-DGGE). The gels from feces of day (d) 0 foals had no or very few ( x = 3, n = 6) bands, which indicates that species richness was low. The number of bands increased during the first 4 days of life, and by d 14 the foals and mares had similar numbers of bands ( x = 28, n = 23). Some bands were present in young foals, but not in mares or in foals on d 42 or d 84, which indicated succession of bacterial species. When the PCR-DGGE profiles were compared with Dice's algorithm, all mare-foal pairwise similarities on d 14 and later were as great as the pairwise similarities between mares. These results are consistent with the idea that foals are born with a sterile gut, colonization proceeds rapidly, and a mature microbial community is present in the first few weeks of life.展开更多
文摘BACKGROUND A previous study compared vortexing and Maki techniques for the diagnosis of catheter-related bloodstream infection(CRBSI),and concluded that vortexing was not superior to Maki method.AIM To determine whether the combined use of vortexing and Maki techniques provides profitability versus the Maki technique for the diagnosis of catheter tip colonization(CTC)and CRBSI.METHODS Observational and prospective study carried out in an Intensive Care Unit.Patients with suspected catheter-related infection(CRI)and with one central venous catheter for at least 7 days were included.The area under the curve(AUC)of the Maki technique,the vortexing technique and the combination of both techniques for the diagnosis of CTC and CRBSI were compared.RESULTS We included 136 episodes of suspected CRI.We found 21 cases of CTC of which 10 were also CRBSI cases.Of the 21 CTC episodes,18(85.7%)were diagnosed by Maki technique and vortexing technique,3(14.3%)only by the technique of Maki,and none only by technique of vortexing.Of the 10 CRBSI episodes,9(90.0%)were diagnosed by the techniques of Maki and vortexing,1(10.0%)was diagnosed only by the technique of Maki,and none only by the technique of vortexing.We no found differences in the comparison of AUC between the technique of Maki and the combination of Maki and vortexing techniques for the diagnosis of CTC(P=0.99)and CRBSI(P=0.99).CONCLUSION The novel finding of our study was that the combined use of vortexing and Maki techniques did not provide profitability to the technique of Maki alone to CRBSI diagnosis of.
文摘BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-acquired infections(HAIs).Studies across various World Health Organization regions have documented a significant incidence of CRAB-related HAIs,with rates as high as 41.7 cases per 1000 patients in ICUs,accounting for 13.6%of all HAIs.These infections pose a doubled mortality risk compared to infections with carbapenem-susceptible Acinetobacter baumannii.A particularly concerning aspect of CRAB colonization is its asymptomatic nature,enabling its transmission through healthcare workers(HCWs)or the NICU environment to vulnerable neonates with developing immune systems.AIM To explore the prevalence of CRAB colonization in NICUs,focusing on neonates,healthcare workers,and the environmental samples,to enhance epidemiological understanding and inform targeted interventions.METHODS We conducted according to PRISMA 2020 checklist guidelines,a comprehensive literature search across multiple databases including MEDLINE(Ovid),EMBASE(Ovid),Global Health(Ovid),Web of Science,and Global Index Me-dicus.Studies were selected based on predetermined criteria,primarily involving neonates,HCWs,and environmental swabs,using culture or molecular methods to detect CRAB colonization.We excluded studies that did not specifically focus on NICUs,were duplicates,or lacked necessary data.The study selection and quality assessment were conducted independently by two reviewers.Data extraction involved collecting comprehensive details about each study.Our statistical analysis used a random-effects model to calculate the pooled prevalence and confidence intervals,stratifying results by regional location.We assessed study heterogeneity using Cochran's Q statistic and I²statistic,with regression tests employed to evaluate potential publication bias.RESULTS We analyzed 737 records from five databases,ultimately including 13 studies from ten countries.For neonates,the pooled prevalence was 4.8%(95%CI:1.1%to 10.5%)with the highest rates observed in South-East Asia(10.5%;95%CI:2.4%to 23.3%).Among HCWs,a single Indian study reported a 3.3%prevalence.Environmental samples showed a prevalence of 2.3%(95%CI:0%to 9.3%),with the highest rates in South-East Asia(10%;95%CI:4.2%to 17.7%).Significant heterogeneity was found across studies,and no publication bias was detected.CONCLUSION This systematic review highlights a significant prevalence of CRAB colonization in neonates across various regions,particularly in South-East Asia,contrasting with lower rates in high-income countries.The study reveals a gap in research on HCWs colonization,with only a single study from India reporting moderate prevalence.Environmental samples indicate moderate levels of CRAB contamination,again higher in South-East Asia.These findings underscore the need for more extensive and focused research on CRAB colonization in NICUs,including exploring the roles of HCWs and the environment in transmission,understanding antimicrobial resistance patterns,and developing effective prevention measures.
基金supported by funding from Lallemand Health Solution(Mirabel,QC)Alberta Milk(Edmonton,AB)+3 种基金the Saskatoon Colostrum Co.Ltd.(Saskatoon,SK)the Natural Sciences and Engineering Research Council of Canada(Ottawa,ON)supported by a Mitacs Accelerate Program from Mitacs Canada(Toronto,ON)Lallemand SAS(Blagnac,France)。
文摘Background As Holstein calves are susceptible to gastrointestinal disorders during the first week of life,understanding how intestinal immune function develops in neonatal calves is important to promote better intestinal health.Feeding probiotics in early life may contribute to host intestinal health by facilitating beneficial bacteria colonization and developing intestinal immune function.The objective of this study was to characterize the impact of early life yeast supplementation and growth on colon mucosa-attached bacteria and host immune function.Results Twenty Holstein bull calves received no supplementation(CON)or Saccharomyces cerevisiae boulardii(SCB)from birth to 5 d of life.Colon tissue biopsies were taken within 2 h of life(D0)before the first colostrum feeding and 3 h after the morning feeding at d 5 of age(D5)to analyze mucosa-attached bacteria and colon transcriptome.Metagenome sequencing showed that there was no difference inαandβdiversity of mucosa-attached bacteria between day and treatment,but bacteria related to diarrhea were more abundant in the colon mucosa on D0 compared to D5.In addition,q PCR indicated that the absolute abundance of Escherichia coli(E.coli)decreased in the colon mucosa on D5 compared to D0;however,that of Bifidobacterium,Lactobacillus,and Faecalibacterium prausnitzii,which could competitively exclude E.coli,increased in the colon mucosa on D5 compared to D0.RNA-sequencing showed that there were no differentially expressed genes between CON and SCB,but suggested that pathways related to viral infection such as“Interferon Signaling”were activated in the colon mucosa of D5 compared to D0.Conclusions Growth affected mucosa-attached bacteria and host immune function in the colon mucosa during the first 5 d of life in dairy calves independently of SCB supplementation.During early life,opportunistic pathogens may decrease due to intestinal environmental changes by beneficial bacteria and/or host immune function.Predicted activation of immune function-related pathways may be the result of host immune function development or suggest other antigens in the intestine during early life.Further studies focusing on the other antigens and host immune function in the colon mucosa are required to better understand intestinal immune function development.
基金funded by the grants from the National Key R&D Program of China(No.2022YFD1301004)National Natural Science Foundation of China(No.31601962)+1 种基金Fundamental Research Funds for the Central Universities(2662019QD021)Key Laboratory of Molecular Animal Nutrition of Zhejiang University(KLMAN202101 and KLMAN202205)。
文摘Colonization and development of the gut microbiome are crucial for the growth and health of calves.In this review,we summarized the colonization,beneficial nutrition,immune function of gut microbiota,function of the gut barrier,and the evolution of core microbiota in the gut of calves of different ages.Homeostasis of gut microbiome is beneficial for nutritional and immune system development of calves.Disruption of the gut microbiome leads to digestive diseases in calves,such as diarrhea and intestinal inflammation.Microbiota already exists in the gut of calf fetuses,and the colonization of microbiota continues to change dynamically under the influence of various factors,which include probiotics,diet,age,and genotype.Colonization depends on the interaction between the gut microbiota and the immune system of calves.The abundance and diversity of these commensal microbiota stabilize and play a critical role in the health of calves.
基金financially supported by the grants from the Inter-governmental International Cooperation Special Project of National Key R&D Program of China(2019YFE0114200)the Natural Science Foundation Project of Science and Technology Department of Jilin Province,China(20200201215JC).
文摘Sclerotinia stem rot,caused by Sclerotinia sclerotiorum,is a destructive soil-borne disease leading to huge yield loss.We previously reported that Klebsiella variicola FH-1 could degrade atrazine herbicides,and the vegetative growth of atrazine-sensitive crops(i.e.,soybean)was significantly increased in the FH-1-treated soil.Interestingly,we found that FH-1 could promote soybean growth and induce resistance to S.sclerotiorum.In our study,strain FH-1 could grow in a nitrogen-free environment,dissolve inorganic phosphorus and potassium,and produce indoleacetic acid and a siderophore.The results of pot experiments showed that K.variicola FH-1 promoted soybean plant development,substantially improving plant height,fresh weight,and root length,and induced resistance against S.sclerotiorum infection in soybean leaves.The area under the disease progression curve(AUDPC)for treatment with strain FH-1 was significantly lower than the control and was reduced by up to 42.2%within 48 h(P<0.001).Moreover,strain FH-1 rcovered the activities of catalase,superoxide dismutase,peroxidase,phenylalanine ammonia lyase,and polyphenol oxidase,which are involved in plant protection,and reduced malondialdehyde accumulation in the leaves.The mechanism of induction of resistance appeared to be primarily resulted from the enhancement of transcript levels of PR10,PR12,AOS,CHS,and PDF1.2 genes.The colonization of FH-1 on soybean root,determined using CLSM and SEM,revealed that FH-1 colonized soybean root surfaces,root hairs,and exodermis to form biofilms.In summary,K.variicola FH-1 exhibited the biological control potential by inducing resistance in soybean against S.sclerotiorum infection,providing new suggestions for green prevention and control.
基金Medical Health Science and Technology Development Plan Project of Shandong Province,No.202103030765Natural Science Foundation of Shandong Province,No.ZR2021QH195 and No.ZR2020QH035.
文摘After being ingested and entering the human stomach,Helicobacter pylori(H.pylori)adopts several effective strategies to adhere to and colonize the gastric mucosa and move to different regions of the stomach to obtain more nutrients and escape from the harsher environments of the stomach,leading to acute infection and chronic gastritis,which is the basis of malignant gastric tumors.The endoscopic manifestations and pathological features of H.pylori infection are diverse and vary with the duration of infection.In this review,we describe the endoscopic manifestations of each stage of H.pylori gastritis and then reveal the potential mechanisms of bacterial intragastric colonization and migration from the perspective of endoscopists to provide direction for future research on the effective therapy and management of H.pylori infection.
基金funded by National Natural Science Foundation of China with the Grant No.31601986Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘Arbuscular mycorrhizal(AM)fungi can form symbiosis with 90%of the vascular plants and play important roles in ecosystem.To realize the AM fungal colonization at different succession stages in saline-alkali land and screen AM fungi species with great functions,roots and soil samples were collected from the three succession stages of Songnen saline-alkali grassland.The soil properties and AM fungal colonization were measured,and the fungus distributed extensively in three stages was annotated by sequencing for AML1/AML2 target,subsequently,maize was selected as the host to verify its colonization.The results showed that the soil properties improved with the succession of saline-alkali grassland.The plants’communities of the three stages could be colonized by AM fungi,and the colonization rate of Leymus chinensis(the third stage)ranged from 66.67%to 100%,Puccinellia tenuiflora(the second stage)ranged from 50%to 80%,while the Suaeda glauca(the first stage)was only 35%–60%.Glomeraceae sp1 was identified as the dominant AM fungi species which occurred frequently in the succession of saline-alkali land with the isolation frequency,relative abundance,and importance value of 100%,18.1%,and 59.1%,respectively.The colonization rate of Glomeraceae sp1 in maize ranged from 80%to 87%and similar mycorrhizal characteristics were detected in the roots of P.tenuiflora,S.glauca,and L.chinensis,indicating that Glomeraceae sp1 colonized the samples in the field.The correlation matrix indicated that colonization rate,colonization intensity,and vesicle abundance were closely related to soil conditions most,and they were related significantly to all the soil properties except cellulase activity.Besides,redundancy analysis(RDA)showed that soil properties drove the changes of AM fungal colonization and sporulation.These results will provide theoretical support for realizing the relationship between AM fungal colonization and soil conditions,and also for the exploration of AM fungi species with great functions.
文摘Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gnotobiotically in flask with semi-solid agar medium. Observations were performed with confocal laser scanning microscopy (CLSM) and electron microscopy, respectively, at 8 d and 12 d after inoculation. Confocal laser scanning microscopy showed that A. brasilense Yu62 could penetrate into the cortex tissue, colonizing in the intercellular spaces of the parenchyma cells of the cortex tissue. Transmission and scanning electron microscopy (TEM) showed that the majority of the bacteria colonized on the root surface and only a minority of them resided in the root interior.
文摘Arbuscular mycorrhizal fungi（AMF） and dark septate endophyte（DSE） colonization were investigated in three different plantation sites（Umdihar,Umsaw and Mawlein） of Meghalaya,northeast India.Isolation and identification of the AMF spore were conducted to evaluate the AMF diversity and host preference in terms of AMF species distribution and abundance in the plantation sites.Results showed that AMF colonization was significantly higher than dark septate endophyte colonization（p〉0.05）.AMF and DSE colonization had a narrow range of colonization,varying from 50.91%-58.95% and 1.84%-4.11%,respectively.Spore density varied significantly in all the sites（p〉0.05）.Out of 29 species identified from 7 genera,the species from Glomus was found to be highly abundant.Sorenson coefficient（Cs） ranged from 0.35-7.0.Species richness varied from 2.0-2.9 in the sites.Total species richness was significantly correlated with total relative abundance（p=0.001）.The distribution,abundance and principal component analysis plot suggest that Glomus macrocarpum,G.multicaulis,G.constrictum and Acaulospora sp 1 were the most host preferred species which possibly may favour the host with proper nutrient acquisition and growth.
基金Supported by A post graduate student grant awarded by Irish Research Council for Science Engineering and Technology(To Dunne C)an award from the Health Research Board Ireland(To Dolan B)a grant from Science Foundation Ireland,No.08/SRC/B1393
文摘Helicobacter pylori(H.pylori)colonizes the stomach of humans and causes chronic infection.The majority of bacteria live in the mucus layer overlying the gastric epithelial cells and only a small proportion of bacteria are found interacting with the epithelial cells.The bacteria living in the gastric mucus may act as a reservoir of infection for the underlying cells which is essential for the development of disease.Colonization of gastric mucus is likely to be key to the establishment of chronic infection.How H.pylori manages to colonise and survive in the hostile environment of the human stomach and avoid removal by mucus flow and killing by gastric acid is the subject of this review.We also discuss how bacterial and host factors may together go some way to explaining the susceptibility to colonization and the outcome of infection in different individuals.H.pylori infection of the gastric mucosa has become a paradigm for chronic infection.Understanding of why H.pylori is such a successful pathogen may help us understand how other bacterial species colonise mucosal surfaces and cause disease.
基金supported by the Beijing Municipal Natural Science Foundation(S170001)the National Natural Science Foundation of China(31630074,31272449 and 31902170)+2 种基金the National Key Research and Development Program of China(2016YFD0500506 and 2018YDF0501002)the 111 Project(B16044)the Jinxinnong Animal Science Developmental Foundation.
文摘Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW)piglets,intrauterine growth restricted(IUGR)piglets have a different intestinal microbiota during their early life,which is related to maternal imprinting on intestinal microbial succession during gestation,at birth and via suckling.Imbalanced allocation of limited nutrients among fetuses during gestation could be one of the main causes for impaired intestinal development and microbiota colonization in neonatal IUGR piglets.In this review,we summarized the potential impact of maternal imprinting on the colonization of the intestinal microbiota in IUGR piglets,including maternal undernutrition,imbalanced allocation of nutrients among fetuses,as well as vertical microbial transmission from mother to offspring during gestation and lactation.At the same time,we give information about the current maternal nutritional strategies(mainly breastfeeding,probiotics and prebiotics)to help colonization of the advantageous intestinal microbiota for IUGR piglets.
基金the Louisiana Rice Research Board for funding this work under the Entomology Program
文摘Interactions between plants and soil microorganisms can influence the other interactions in which plants participate, including interactions with herbivores. Many fungi, including arbuscular mycorrhizal fungi(AMF), form symbiotic relationships with the roots they inhabit, and potentially alter defense against pests. The objective of this study was to document the extent of root colonization by AMF on non-flooded rice plants grown under conditions typical of commercial fields. We hypothesized that AMF naturally colonized rice plants in different rice producing field locations. Rice plant samples were collected from areas across the southern United States, including Texas, Mississippi, Arkansas and two research stations in Louisiana. We quantified the amount of AMF colonization in insecticide-free rice plants over three consecutive years(2014–2016). The results revealed natural colonization of AMF in all rice producing areas. In all the three years of survey, rice-AMF associations were the greatest in Arkansas followed by Mississippi and Texas. This research will help draw attention to natural colonization of AMF in rice producing areas that can impact future rice research and production by facilitating agricultural exploitation of the symbiosis.
基金supported by the National Key R&D Program of China[2018YFC1200400]the Nature Science Foundation of the Jiangsu Higher Education Institutions of China[14KJA220002]+1 种基金the Postgraduate Scientific Research and Innovation Program of Jiangsu Province[KYLX16_0859]the National Natural Science Foundation of China[31370643]。
文摘Bacillus cereus NJSZ-13,an endophytic bacterium with nematicidal activity,was isolated from stems of healthy Pinus elliottii Engelm.Colonization of P.massoniana Lamb.by endophytic B.cereus was studied using scanning electron microscopy and confocal laser scanning microscopy.After the plasmid p GFP78 containing the green fluorescent protein(GFP)gene was transformed into the NJSZ-13 strain,the NJSZ-13:gfp showed the same nematicidal activity and growth curve as the wild-type strain,and the plasmid p GFP78 was stably maintained in strain NJSZ-13 for at least 96 h of bacterial cultivation on medium without antibiotics.After inoculation into Masson pine roots,colonization of the NJSZ-13:gfp strain in plant roots and stems was visualized using confocal laser scanning and the strain was enumerated in inoculated roots and stems.These results suggest that NJSZ-13:gfp is an efficient colonizer of Masson pine and can transfer vertically from roots to stems.
基金Supported by grants from National Science Council, Taiwan No.NSC93-2316-B-006-011 and NSC91-2320-B-006-091
文摘AIM： To characterize the role of flgK and its protein product in Hpylori colonization. METHODS： The PCR cloning method identified the flgK gene. An isogenic flgK mutant was constructed by gene replacement and confirmed by Southern blot analysis and PCR analysis. The recombinant FlgK protein （r-FlgK） was purified. Electron microscopy （EM） was applied to demonstrate the flagella of H pylori. An in vitro motility test was assessed in semisolid medium. The densities of H pylori colonization with either the wild-type strain or its flgK mutant were compared among BALB/c mice with or without pre-immunization with r-FlgK. The serological responses to r-FlgK were analyzed for 70 clinical patients with different densities of H pylori colonization. RESULTS： From a duodenal ulcer strain, the flgK gene was cloned and it contained 1821 bp, with a 95.7% identity to the published sequences. No flagella were observed under EM for the mutant strain, which had a loss of motility. Hpylori density was lower in the BALB/c mice inoculated by the mutant or with pre-immunization with r-FlgK compared to unimmunized mice or mice inoculated by the wild-type strain （P 〈 0.05）. In the H pylori-infected patients, the serological responses to r-FlgK were uniformly low in titer.CONCLUSION： FlgK encoded by flgK is important for flagella formation and H pylori motility. Deficiency in FlgK or an enhanced serological response to r-FlgK can interfere with Hpylori colonization. FlgK of Hpylori could be a novel target for vaccination.
基金Supported by In part by Zhejiang Provincial Natural Science Foundation,No.LY12H04005 and LY13H040011
文摘The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis.
基金supported by grants from the National Natural Sciences Foundation of China(Nos.10875048,30700717)
文摘The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse（n=80） by using a punch biopsy.The mice were assigned randomly into two groups,with 40 animals in each group：a non-thermal plasma group in which the mice were treated with the non-thermal plasma;a control group in which the mice were left to heal naturally.Wound healing was evaluated on postoperative days（POD） 4,7,10 and 14（n=5 per group in each POD） by percentage of wound closure.The mice was euthanized on POD 1,4,7,10,14,21,28 and 35（n=1 in each POD）.The wounds were removed,routinely fixed,paraffin-embedded,sectioned and HE-stained.A modified scoring system was used to evaluate the wounds.The results showed that acute inflammation peaked on POD 4 in non-thermal plasma group,earlier than in control group in which acute inflammation reached a peak on POD 7,and the acute inflammation scores were much lower in non-thermal group than in control group on POD 7（P0.05）.The amount of granular tissue was greater on POD 4 and 7 in non-thermal group than in control group（P0.05）.The re-epithelialization score and the neovasularization score were increased significantly in non-thermal group when compared with control group on POD 7 and 10（P0.05 for all）.The count of bacterial colonies was 103 CFU/mL on POD 4 and 20 CFU/mL on POD 7,significantly lower than that in control group（109 CFU/mL on POD 4 and 1012 CFU/mL on the POD 7）（P0.05）.It was suggested that the non-thermal plasma facilitates the wound healing by suppressing bacterial colo-nization.
基金funded by the National Natural Science Foundation Project of China(Grant No.31100358)the Ministry of Science and Technology of China(Grant No.2011BAC09B0404)
文摘Fragmentation and loss of habitats due to natural disasters, like earthquakes and earthquaketriggered debris flows are existing threats to the long- term survival of the giant panda （Ailuropoda melanoleuca）. To better understand natural recovery processes of the damaged habitat, field investigation and laboratory analysis were used to analyze relationships between plant colonization and soil characteristics in an over 3o-year natural recovery of a damaged giant panda habitat in a debris flow gully after the 1976 Songpan-Pingwu earthquake in Sichuan Province, China. Four different damaged sites were selected that located at the center of the gully （center）, on a flat alluvial fan （fan）, in a side slope of the gully （slope）, and at the ecotone between the gully and native forest （ecotone）. Vegetation characteristics, soil physicochemical properties, and microbial biomass in the different sites and soil depths were measured. After the natural recovery, the soil fertility, water retention, and microbial biomass were highest at ecotone, followed by fan, slope, and center. Only a few perennial herbs colonized at center; shrubs started to invade at fan and slope, and the native trees dominated the community of ecotone. Furthermore, Fargesia spathacea （food for the giant panda） started to be re-established at ecotone, and the community characteristic of ecotone recovered similarly to the native habitat. These results suggested that improving the soil fertility, water retaining capacity and microbial biomass is fundamental to the plant colonization, particular for F. spathacea＇s re- establishment in a damaged giant panda habitat.
文摘The fungus U. virens is the causal agent of rice false smut disease. The green fluorescent protein (GFP) was used to mark this fungus in order to visualize and analyze the colonization and infection processes in vivo. Using epifluorescence microscopy colonization and infection on rice roots were visualized in vivo. After inoculation for 2 to 15 d, it was observed that the conidia and their germ-tubes had penetrated into epidermis of young roots. The hyphae were found inside the root xylem 18 d after inoculation. Generally, the transformed fungus colonized the rhizosphere, the cortex as well as the vascular tissues with symptoms of root necrosis observed. The results of this work show that U. virens colonize not only rice panicles but also the roots.
基金This work was supported by the National Natural Science Foundation of China(31601986)the Fundamental Research Funds for the Central Universities(2572018BK02)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16005).
文摘To understand arbuscular mycorrhizal(AM)fungi resources and develop AM fungal species in ornamental plants with saline-alkaline tolerances,Iris lactea,which grows in the Songnen saline-alkaline grassland with a high ornamental value,was selected as the experimental material,and the colonization characteristics of its roots and the AM fungal diversity in its rhizosphere were explored.The results of the observations and calculations of mycorrhizae from ten different samples showed that AM fungi colonized the roots of I.lactea and formed Arum-type mycorrhizal structures.There was a significant correlation between soil spore density and pH value,while the colonization rate showed a fluctuating trend with increasing pH values.The observed colonization intensities were of Levels II(1%–10%)or III(11%–50%),and the vesicle abundances were of grades A2 or A3 among different sites.AM fungi produced a large number of mycelia and vesicles in the roots of I.lactea after colonization.Thirty-seven species belonging to 15 genera of AM fungi were isolated from the rhizosphere of I.lactea and identified by morphological identification.Funneliformis and Glomus were the dominant genera,accounting for 21.79%and 20.85%of the total number,respectively.F.mosseae and Rhizophagus intraradices were isolated in all samples with importance values of 58.62 and 51.19,respectively.These results are expected to provide a theoretical basis for the analysis of the salt tolerance mechanism of I.lactea and for the discovery,exploration and further screening of AM fungal resources with salinity tolerances in saline-alkaline soils.
文摘Horses, like all animals, are born without the symbiotic microbes that occupy the gastrointestinal tracts of mature animals. As grazing animals, horses rely on these microbes to fully utilize the grasses and other cellulosic feeds that they consume. Thus, colonization of the foal's gastrointestinal tract must occur between birth and weaning. The feces of nine mare and foal pairs were sampled from the day of parturition until 12 weeks of age, and the samples were analyzed by polymerase chain reaction amplification of the bacterial 16S rRNA gene and denaturing gradient gel electrophoresis (PCR-DGGE). The gels from feces of day (d) 0 foals had no or very few ( x = 3, n = 6) bands, which indicates that species richness was low. The number of bands increased during the first 4 days of life, and by d 14 the foals and mares had similar numbers of bands ( x = 28, n = 23). Some bands were present in young foals, but not in mares or in foals on d 42 or d 84, which indicated succession of bacterial species. When the PCR-DGGE profiles were compared with Dice's algorithm, all mare-foal pairwise similarities on d 14 and later were as great as the pairwise similarities between mares. These results are consistent with the idea that foals are born with a sterile gut, colonization proceeds rapidly, and a mature microbial community is present in the first few weeks of life.
