In the present work, a comparative study of antibacterial activity and synergistic effects of triangular silver nanoparticles in combination with two standard antibiotics is discussed for Staphylococcus aureus and Pse...In the present work, a comparative study of antibacterial activity and synergistic effects of triangular silver nanoparticles in combination with two standard antibiotics is discussed for Staphylococcus aureus and Pseudomonas aeruginosa. A green route was developed to synthesise silver nanoparticles in which silver oxalate was taken as precursor, black tea leaves extract as surfactant and chitin as a stabilizing agent. A grey coloured colloidal solution of silver nanoparticles was obtained which was characterized by using various techniques like X-ray diffractometer (XRD), transmission electron microscopy (TEM) and UV-visible spectroscopy. Anti-bacterial studies gave approximately equal inhibition zones for both the combinations which states that silver nanoparticles are to be equally effective and synergistic effects were clearly observed in case of P. aeruginosa.展开更多
The potential role of personal items in the transmission of pathogens is poorly understood. In this study, we cultured bacteria of public health importance found on wristbands, determined whether there is a correlatio...The potential role of personal items in the transmission of pathogens is poorly understood. In this study, we cultured bacteria of public health importance found on wristbands, determined whether there is a correlation between wristband material and prevalence, and tested three household disinfectants for efficacy in reducing bacteria on wristbands made of plastic, rubber, metal, and cloth, using standard microbiological assays. Total cultivable bacteria, Staphylococci, Enterobacteria (Escherichia coli), and Pseudomonas on 20 smartwatch wristbands were cultured from randomly recruited subjects. Nearly all wristbands (95%) were contaminated, with the highest average numbers of 3.46E+4 cfu/cm<sup>2</sup> and 1.52E+4 cfu/cm<sup>2</sup> on rubber and plastic bands respectively. Metallic gold and silver wristbands had zero to 18 cfu/cm<sup>2</sup>. While the high prevalence of Staphylococcus spp (85% of wristbands)—skin microbiota;was not unexpected, the occurrence of Pseudomonas spp (30%), and enteric bacteria (60%), even at relatively low numbers is of public health significance. Bacterial load on individual subjects varied remarkably with males and females harboring average total bacteria of 4.045 and 3.42 log<sub>10</sub>cfu/cm<sup>2</sup> of wristband, respectively. The most important predictor of wristband bacteria load was the texture of wristband material and activity (hygiene) of the subject at sampling time. Potential pathogens—Staphylococcus aureus (8143 cfu/cm<sup>2</sup>) and Pseudomonas spp. (1126 cfu/cm<sup>2</sup>) were most abundant on cloth and rubber wristbands, respectively, while the presence of the E. coli group was associated with animal handling activity by a veterinarian. Lysol Disinfectant Spray and 70% Ethanol were highly effective regardless of wristband material with >99.99% kill rate and a log cfu/cm<sup>2</sup> reduction of 3 - 4.0 and 3 - 4.5 respectively within 30 seconds. Apple Cider Vinegar (ACV) was not as potent. Only 2 - 3.5 log cfu/cm<sup>2</sup> drop was obtained after 120 seconds of exposure. Further susceptibility assays with standard reference bacteria showed that Lysol and 70% alcohol effectively killed > 99.99% (>8 log CFU drop) of Escherichia coli strain 7001, Staphylococcus aureus strain 6538, and Pseudomonas aeruginosa strain 10662 within 30 seconds of contact. Vinegar had a similar efficacy on the gram negatives but little or no effect on Staph aureus (only a 2-log CFU/ml reduction in 5 minutes!) The high prevalence of potential pathogens, some of which could be reservoirs of antibiotic resistance reveals a weak link in infection control and underscores the need for regular cleaning of personal and hand-held accessories with adequate considerations of their texture.展开更多
Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three t...Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannanbinding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP.Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays.Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05).Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.展开更多
Pathogen microorganisms exist in various environments such as dairy processing facilities. They are not easily eliminated, and significantly raise the risk of bacterial contamination. The inhibition ability of a novel...Pathogen microorganisms exist in various environments such as dairy processing facilities. They are not easily eliminated, and significantly raise the risk of bacterial contamination. The inhibition ability of a novel type 304 Cu-bearing stainless steel （304CUSS） with nano-sized Cu-rich precipitates against Staph-ylococcus aureus （S. aureus） and Pseudomonas aeruginosa （P. aeruginosa） added whole milk was investigated in this study. The results showed that after 24 h contact, the inhibition rates of the 304CUSS against S. aureus and P. aeruginosa added whole milk reached 99.2% ± 0.3% and 99.3% ± 0.2%, respectively, in contrast with the 304SS. In the plain whole milk, the inhibition rate of the 304CUSS also reached 66.9% ± 2.0% compared with the 304SS. The results demonstrated that the 304CUSS killed majority of the planktonic bacteria, and inhibited sessile bacteria adherence to the steel surface in the whole milk with and without bacteria addition, significantly reducing the bacterial growth rate. These research outcomes explicitly show an application potential of this novel antibacterial stainless steel in the dairy related food industry.展开更多
Effect of the ozonated oil in liposomes: they act against Staphylococcus aureus and Pseudomonas aeruginosa is among the most frequent eye pathogens and causes acute and chronic infections of the ocular surface. Staphy...Effect of the ozonated oil in liposomes: they act against Staphylococcus aureus and Pseudomonas aeruginosa is among the most frequent eye pathogens and causes acute and chronic infections of the ocular surface. Staphylococcus aureus and Pseudomonas aeruginosa were tested in this study. The bacterial suspension of Staphylococcus aureus was diluted to obtain 150 CFU/ml. The bacterial suspension of Pseudomonas aeruginosa was diluted to obtain 15 CFU/ml. Various volumes of liposome-vehiculated ozonated oil were added (400 μl, 200 μl, 100 μl and 50 μl) to 100 μl of bacterial suspension;both of Staphylococcus aureus and Pseudomonas aeruginosa are incubated at 37?C for 10 minutes. The cytotoxicity of liposome-vehiculated ozonated oil was analysed at the University of Campania “Luigi Vanvitelli”, Department of Precision Medicine. The HaCaT epidermal keratinocyte cell line (ATCC, USA) was grown in Dulbecco’s Modified Eagle Medium (Euroclone) with the addition of 10% foetal bovine serum (FBS) (Euroclone), 2 mM of L-glutamine (Euroclone) and antibiotics (100 U/ml penicillin, 100 g/ml streptomycin) (Euroclone). The microbiological results clearly show the antimicrobial efficacy of liposome-vehiculated ozonated oil against bacterial strains such as Staphylococcus aureus and Pseudomonas aeruginosa. Furthermore, the studies carried out in vitro on the keratinocyte line showed how ozonated oil in liposomes does not evidence any cell toxicity, and that after 3 days of treatment, it promotes cell growth compared to the positive control.展开更多
Disinfection was investigated in high-density ozone produced by dielectric barrier discharge under atmospheric pressure. Disinfection was studied on three-dimensional carriers made of hydrophilic vinyl-polysiloxane im...Disinfection was investigated in high-density ozone produced by dielectric barrier discharge under atmospheric pressure. Disinfection was studied on three-dimensional carriers made of hydrophilic vinyl-polysiloxane impression material and granular acrylic resin used for oral surgery. Experimental results indicate disinfection of spore-forming bacteria: Geobacillus stearothermophilus and Bacillus atrophaeus, and selected species of opportunistic pathogens: Aspergillus niger, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Candida albicans.展开更多
Bacterial biofilms have been implicated with breast implant complications including capsular contracture, double-capsule formation, and breast implant-associated anaplastic large cell lymphoma. However, the relationsh...Bacterial biofilms have been implicated with breast implant complications including capsular contracture, double-capsule formation, and breast implant-associated anaplastic large cell lymphoma. However, the relationship between implant surface texture and microbial biofilm formation is insufficiently evaluated. In the present study, we examined the antimicrobial activities of different types of silicone breast implant. The growth of bacterial including <em>Staphylococcus aureus</em>, <em>Staphylococcus epidermidis</em>, and <em>Pseudomonas aeruginosa</em> was compared using implants with various surface textures, including Hans Smooth, Hans SmoothFine, Allergan Smooth, Eurosilicone Smooth, Eurosilicone Texture, Sebbin Smooth, Sebbin Micro, Sebbin Texture, and Motiva Smooth. Microbial investigation revealed the increased growth of <em>S. aureus</em> on breast implants after 48 h, except Eurosilicone Smooth, Eurosilicone Texture, Hans SmoothFine and Sebbin Smooth material. At 48 hours, there was no major difference between the <em>S. aureus</em> attachment on smooth and textured implants. The results of <em>S. epidermis</em> attachment on the implant after 48 h showed that their growth decreased on surfaces of Motiva Smooth, Sebbin Smooth, and Eurosilicone Smooth. These results indicated that <em>S. epidermis</em> was unable to survive on these breast implants. Eventually, <em>P. aeruginosa</em> count had showed decrease of bacterial count after 48 hours compared to 24 hours in most of the implants except for Eurosilicone Texture, Sebbin Smooth and Sebbin Micro, where the count of <em>P. aeruginosa</em> slightly increased. This indicated that <em>P. aeruginosa</em> was unable to exist on the smooth surfaces. Our results show that the in vitro assay revealed no significant difference between smooth and textured surfaces and showed variable interactions and needed further molecular analysis to assess their adherence nature.展开更多
AIM:To evaluate the pathogens in cultured Jones tubes used in lacrimal bypass surgery according to the postoperative periods and to obtain data for the prevention of infection of functional lacrimal stent invention.ME...AIM:To evaluate the pathogens in cultured Jones tubes used in lacrimal bypass surgery according to the postoperative periods and to obtain data for the prevention of infection of functional lacrimal stent invention.METHODS:Totally 71 patients(81 eyes)who underwent the removal of Jones tubes were enrolled in study.All the removed Jones tubes were cultured for bacterial and fungal identification and tested for bacterial antibiotic sensitivity.The results were analyzed according to the duration of the inserted Jones tube after lacrimal bypass surgery.RESULTS:Of the 81 eyes,bacteria were isolated from 69 eyes(85.2%)and fungi from 6 eyes(7.4%).Among 69 eyes,40.6% showed Staphylococcus aureus(S.aureus),11.6% were Pseudomonas aeruginosa(P.aeruginosa).Gram-positive bacteria were isolated more than Gramnegative bacteria,but Gram-negative bacteria showed a higher incidence in the Jones tube implanted for over 10y(P=0.035).The antibiotic sensitivity test showed that 46.4% of S.aureus were resistant to oxacillin.In terms of antibiotics commonly used in ocular clinical practice,vancomycin was sensitive to S.aureus and Streptococcus pneumoniae(S.pneumoniae),amikacin responded to P.aeruginosa and Proteus mirabilis(P.mirabilis).Trimethoprim/sulfamethoxazole(TMP/SMX)was all sensitive to S.aureus,S.pneumoniae and P.mirabilis except P.aeruginosa.CONCLUSION:S.aureus is the most commonly found organism in the Jones tube after lacrimal bypass surgery,and 46.4% of them are methicillin-resistant S.aureus(MRSA),sensitive to vancomycin.Especially,P.mirabilis responded with amikacin is dominantly detected in the Jones tubes implanted for more than 10y.展开更多
Animal models are essential for the development of new anti-infectious drugs.Although some bacterial infection models have been established in rodents,small primate models are rare.Here,we report on two bacterial infe...Animal models are essential for the development of new anti-infectious drugs.Although some bacterial infection models have been established in rodents,small primate models are rare.Here,we report on two bacterial infection models established in tree shrew（Tupaia belangeri chinensis）.A burnt skin infection model was induced by dropping 5×106 CFU of Staphylococcus aureus on the surface of a wound after a third degree burn.This dose of S.aureus caused persistent infection for 7 days and obvious inflammatory response was observed 4 days after inoculation.A Dacron graft infection model,2×106 CFU of Pseudomonas aeruginosa also caused persistent infection for 6 days,with large amounts of pus observed 3 days after inoculation.These models were used to evaluate the efficacy of levofloxacin（LEV） and cefoperazone（CPZ）,which reduced the viable bacteria in skin to 4log10 and 5log10 CFU/100 mg tissue,respectively.The number of bacteria in graft was significantly reduced by 4log10 CFU/mL treatment compared to the untreated group（P0.05）.These results suggest that two bacterial infection models were successfully established in tree shrew using P.aeruginosa and S.aureus.In addition,tree shrew was susceptible to P.aeruginosa and S.aureus,thus making it an ideal bacterial infection animal model for the evaluation of new antimicrobials.展开更多
Quorum sensing(QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation,...Quorum sensing(QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed.展开更多
Objective:To examine the anti-bacterial activity of leaf extracts of Morus alba L.(Moraceae)and Piper betel L.(Piperaceae),and seed extracts of Bombax ceiba L.(Borabacaceae).Methods:We have partially purified plant ex...Objective:To examine the anti-bacterial activity of leaf extracts of Morus alba L.(Moraceae)and Piper betel L.(Piperaceae),and seed extracts of Bombax ceiba L.(Borabacaceae).Methods:We have partially purified plant extracts by solvent extraction method,and evaluated the effect of individual fractions on bacterial growth using Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Staphylococcus aureus(S.aureus) bacterial strains.Results:Compared with Morus and Bombax fractions,Piper fractions showed significant growth inhibition on all the three types of bacteria studied.The EtOAc-hexane fractions of Piper leaves exhibited significant antibacterial activity with minimum inhibitory concentrations(MIC) of 50 μg/mL culture against both gram-positive and gram-negative bacteria.The EtOAc-fractions Ⅰ,Ⅱ,and Ⅳ inhibited bacterial colony formation on soft agar in addition to growth inhibition.A combination treatment of piper fractions with ampicillin resulted in significant growth inhibition in E.coli and P.aeruginosa,and combination with anticancer drug geldanamycin(2 μg/mL) showed selective growth inhibition against P.aeruginosa and S.aureus.Three major compounds,i.e.,eugenol,3-hexene-ol and stigmasterol,were primarily identified from Piper betel leaf extractions.Among the individual compounds,eugenol treatment showed improved growth inhibition compared with stigmasterol and 3-hexene-ol.Conclusions:We are reporting potential anti-bacterial compounds from Piper betel against both gram-positive and gram-negative bacteria either alone or in combination with drug treatment.展开更多
There are numerous reports regarding the antimicrobial effects of herbal extracts on bacteria and fungi. We have prepared water extracts of Wild Leek （A. ampeloprasum var. porrum）, Kurrat （A. ampeloprasum var. kur...There are numerous reports regarding the antimicrobial effects of herbal extracts on bacteria and fungi. We have prepared water extracts of Wild Leek （A. ampeloprasum var. porrum）, Kurrat （A. ampeloprasum var. kurrat） and Elephant Garlic （A. ampeloprasum var. ampeloprasum） by rotary vacuum distillation. As a result, the extraction was carried out in 40 ℃ thus omitting any risk of loss of anti-bacterial activity due to high temperatures reported in prior similar studies [ 1]. The five bacteria Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus were tested against the extracts. While some extent of inhibition was observed when the bacteria were cultured in presence of the leek and kurrat extracts, elephant garlic was determined to possess an extreme inhibitory quality against all the aforementioned bacteria, completely inhibiting the growth of the bacteria after 24 hrs of culture in exposure to the extract. We propose that elephant garlic extract could be an effective alternative to chemical antibiotic treatments and disinfectants in hospital and other settings in which infections are common.展开更多
文摘In the present work, a comparative study of antibacterial activity and synergistic effects of triangular silver nanoparticles in combination with two standard antibiotics is discussed for Staphylococcus aureus and Pseudomonas aeruginosa. A green route was developed to synthesise silver nanoparticles in which silver oxalate was taken as precursor, black tea leaves extract as surfactant and chitin as a stabilizing agent. A grey coloured colloidal solution of silver nanoparticles was obtained which was characterized by using various techniques like X-ray diffractometer (XRD), transmission electron microscopy (TEM) and UV-visible spectroscopy. Anti-bacterial studies gave approximately equal inhibition zones for both the combinations which states that silver nanoparticles are to be equally effective and synergistic effects were clearly observed in case of P. aeruginosa.
文摘The potential role of personal items in the transmission of pathogens is poorly understood. In this study, we cultured bacteria of public health importance found on wristbands, determined whether there is a correlation between wristband material and prevalence, and tested three household disinfectants for efficacy in reducing bacteria on wristbands made of plastic, rubber, metal, and cloth, using standard microbiological assays. Total cultivable bacteria, Staphylococci, Enterobacteria (Escherichia coli), and Pseudomonas on 20 smartwatch wristbands were cultured from randomly recruited subjects. Nearly all wristbands (95%) were contaminated, with the highest average numbers of 3.46E+4 cfu/cm<sup>2</sup> and 1.52E+4 cfu/cm<sup>2</sup> on rubber and plastic bands respectively. Metallic gold and silver wristbands had zero to 18 cfu/cm<sup>2</sup>. While the high prevalence of Staphylococcus spp (85% of wristbands)—skin microbiota;was not unexpected, the occurrence of Pseudomonas spp (30%), and enteric bacteria (60%), even at relatively low numbers is of public health significance. Bacterial load on individual subjects varied remarkably with males and females harboring average total bacteria of 4.045 and 3.42 log<sub>10</sub>cfu/cm<sup>2</sup> of wristband, respectively. The most important predictor of wristband bacteria load was the texture of wristband material and activity (hygiene) of the subject at sampling time. Potential pathogens—Staphylococcus aureus (8143 cfu/cm<sup>2</sup>) and Pseudomonas spp. (1126 cfu/cm<sup>2</sup>) were most abundant on cloth and rubber wristbands, respectively, while the presence of the E. coli group was associated with animal handling activity by a veterinarian. Lysol Disinfectant Spray and 70% Ethanol were highly effective regardless of wristband material with >99.99% kill rate and a log cfu/cm<sup>2</sup> reduction of 3 - 4.0 and 3 - 4.5 respectively within 30 seconds. Apple Cider Vinegar (ACV) was not as potent. Only 2 - 3.5 log cfu/cm<sup>2</sup> drop was obtained after 120 seconds of exposure. Further susceptibility assays with standard reference bacteria showed that Lysol and 70% alcohol effectively killed > 99.99% (>8 log CFU drop) of Escherichia coli strain 7001, Staphylococcus aureus strain 6538, and Pseudomonas aeruginosa strain 10662 within 30 seconds of contact. Vinegar had a similar efficacy on the gram negatives but little or no effect on Staph aureus (only a 2-log CFU/ml reduction in 5 minutes!) The high prevalence of potential pathogens, some of which could be reservoirs of antibiotic resistance reveals a weak link in infection control and underscores the need for regular cleaning of personal and hand-held accessories with adequate considerations of their texture.
基金funded by the National Key R&D Program of China[2021YFC2301102]National Natural Science Foundation of China[82202593]Key R&D Program of Hebei Province[223777100D].
文摘Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannanbinding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP.Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays.Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05).Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.
基金financially supported by the National Natural Science Foundation of China(Nos.51101154 and 51371168)the National Basic Research Program of China(No.2012CB619101)the UK Royal Academy of Engineering(RAEng.1213RECI052)
文摘Pathogen microorganisms exist in various environments such as dairy processing facilities. They are not easily eliminated, and significantly raise the risk of bacterial contamination. The inhibition ability of a novel type 304 Cu-bearing stainless steel （304CUSS） with nano-sized Cu-rich precipitates against Staph-ylococcus aureus （S. aureus） and Pseudomonas aeruginosa （P. aeruginosa） added whole milk was investigated in this study. The results showed that after 24 h contact, the inhibition rates of the 304CUSS against S. aureus and P. aeruginosa added whole milk reached 99.2% ± 0.3% and 99.3% ± 0.2%, respectively, in contrast with the 304SS. In the plain whole milk, the inhibition rate of the 304CUSS also reached 66.9% ± 2.0% compared with the 304SS. The results demonstrated that the 304CUSS killed majority of the planktonic bacteria, and inhibited sessile bacteria adherence to the steel surface in the whole milk with and without bacteria addition, significantly reducing the bacterial growth rate. These research outcomes explicitly show an application potential of this novel antibacterial stainless steel in the dairy related food industry.
文摘Effect of the ozonated oil in liposomes: they act against Staphylococcus aureus and Pseudomonas aeruginosa is among the most frequent eye pathogens and causes acute and chronic infections of the ocular surface. Staphylococcus aureus and Pseudomonas aeruginosa were tested in this study. The bacterial suspension of Staphylococcus aureus was diluted to obtain 150 CFU/ml. The bacterial suspension of Pseudomonas aeruginosa was diluted to obtain 15 CFU/ml. Various volumes of liposome-vehiculated ozonated oil were added (400 μl, 200 μl, 100 μl and 50 μl) to 100 μl of bacterial suspension;both of Staphylococcus aureus and Pseudomonas aeruginosa are incubated at 37?C for 10 minutes. The cytotoxicity of liposome-vehiculated ozonated oil was analysed at the University of Campania “Luigi Vanvitelli”, Department of Precision Medicine. The HaCaT epidermal keratinocyte cell line (ATCC, USA) was grown in Dulbecco’s Modified Eagle Medium (Euroclone) with the addition of 10% foetal bovine serum (FBS) (Euroclone), 2 mM of L-glutamine (Euroclone) and antibiotics (100 U/ml penicillin, 100 g/ml streptomycin) (Euroclone). The microbiological results clearly show the antimicrobial efficacy of liposome-vehiculated ozonated oil against bacterial strains such as Staphylococcus aureus and Pseudomonas aeruginosa. Furthermore, the studies carried out in vitro on the keratinocyte line showed how ozonated oil in liposomes does not evidence any cell toxicity, and that after 3 days of treatment, it promotes cell growth compared to the positive control.
文摘Disinfection was investigated in high-density ozone produced by dielectric barrier discharge under atmospheric pressure. Disinfection was studied on three-dimensional carriers made of hydrophilic vinyl-polysiloxane impression material and granular acrylic resin used for oral surgery. Experimental results indicate disinfection of spore-forming bacteria: Geobacillus stearothermophilus and Bacillus atrophaeus, and selected species of opportunistic pathogens: Aspergillus niger, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Candida albicans.
文摘Bacterial biofilms have been implicated with breast implant complications including capsular contracture, double-capsule formation, and breast implant-associated anaplastic large cell lymphoma. However, the relationship between implant surface texture and microbial biofilm formation is insufficiently evaluated. In the present study, we examined the antimicrobial activities of different types of silicone breast implant. The growth of bacterial including <em>Staphylococcus aureus</em>, <em>Staphylococcus epidermidis</em>, and <em>Pseudomonas aeruginosa</em> was compared using implants with various surface textures, including Hans Smooth, Hans SmoothFine, Allergan Smooth, Eurosilicone Smooth, Eurosilicone Texture, Sebbin Smooth, Sebbin Micro, Sebbin Texture, and Motiva Smooth. Microbial investigation revealed the increased growth of <em>S. aureus</em> on breast implants after 48 h, except Eurosilicone Smooth, Eurosilicone Texture, Hans SmoothFine and Sebbin Smooth material. At 48 hours, there was no major difference between the <em>S. aureus</em> attachment on smooth and textured implants. The results of <em>S. epidermis</em> attachment on the implant after 48 h showed that their growth decreased on surfaces of Motiva Smooth, Sebbin Smooth, and Eurosilicone Smooth. These results indicated that <em>S. epidermis</em> was unable to survive on these breast implants. Eventually, <em>P. aeruginosa</em> count had showed decrease of bacterial count after 48 hours compared to 24 hours in most of the implants except for Eurosilicone Texture, Sebbin Smooth and Sebbin Micro, where the count of <em>P. aeruginosa</em> slightly increased. This indicated that <em>P. aeruginosa</em> was unable to exist on the smooth surfaces. Our results show that the in vitro assay revealed no significant difference between smooth and textured surfaces and showed variable interactions and needed further molecular analysis to assess their adherence nature.
文摘AIM:To evaluate the pathogens in cultured Jones tubes used in lacrimal bypass surgery according to the postoperative periods and to obtain data for the prevention of infection of functional lacrimal stent invention.METHODS:Totally 71 patients(81 eyes)who underwent the removal of Jones tubes were enrolled in study.All the removed Jones tubes were cultured for bacterial and fungal identification and tested for bacterial antibiotic sensitivity.The results were analyzed according to the duration of the inserted Jones tube after lacrimal bypass surgery.RESULTS:Of the 81 eyes,bacteria were isolated from 69 eyes(85.2%)and fungi from 6 eyes(7.4%).Among 69 eyes,40.6% showed Staphylococcus aureus(S.aureus),11.6% were Pseudomonas aeruginosa(P.aeruginosa).Gram-positive bacteria were isolated more than Gramnegative bacteria,but Gram-negative bacteria showed a higher incidence in the Jones tube implanted for over 10y(P=0.035).The antibiotic sensitivity test showed that 46.4% of S.aureus were resistant to oxacillin.In terms of antibiotics commonly used in ocular clinical practice,vancomycin was sensitive to S.aureus and Streptococcus pneumoniae(S.pneumoniae),amikacin responded to P.aeruginosa and Proteus mirabilis(P.mirabilis).Trimethoprim/sulfamethoxazole(TMP/SMX)was all sensitive to S.aureus,S.pneumoniae and P.mirabilis except P.aeruginosa.CONCLUSION:S.aureus is the most commonly found organism in the Jones tube after lacrimal bypass surgery,and 46.4% of them are methicillin-resistant S.aureus(MRSA),sensitive to vancomycin.Especially,P.mirabilis responded with amikacin is dominantly detected in the Jones tubes implanted for more than 10y.
基金financially supported by the Project from the Chinese Academy of Sciences (KSCX2-EW-R-11)the Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences&Yunnan Province (KSCX2-EW-J-23)Science and Technology Department of Yunnan Province (2011C1139)
文摘Animal models are essential for the development of new anti-infectious drugs.Although some bacterial infection models have been established in rodents,small primate models are rare.Here,we report on two bacterial infection models established in tree shrew（Tupaia belangeri chinensis）.A burnt skin infection model was induced by dropping 5×106 CFU of Staphylococcus aureus on the surface of a wound after a third degree burn.This dose of S.aureus caused persistent infection for 7 days and obvious inflammatory response was observed 4 days after inoculation.A Dacron graft infection model,2×106 CFU of Pseudomonas aeruginosa also caused persistent infection for 6 days,with large amounts of pus observed 3 days after inoculation.These models were used to evaluate the efficacy of levofloxacin（LEV） and cefoperazone（CPZ）,which reduced the viable bacteria in skin to 4log10 and 5log10 CFU/100 mg tissue,respectively.The number of bacteria in graft was significantly reduced by 4log10 CFU/mL treatment compared to the untreated group（P0.05）.These results suggest that two bacterial infection models were successfully established in tree shrew using P.aeruginosa and S.aureus.In addition,tree shrew was susceptible to P.aeruginosa and S.aureus,thus making it an ideal bacterial infection animal model for the evaluation of new antimicrobials.
基金Supported by JSPS grant Challenging Exploratory Research,No.25660062SEP-CONACyT grant,No.152794(García-Contreras R)+3 种基金Fideicomiso COLPOS 167304 and Programa Cátedras-CONACyT 2112(Castillo-Juárez)the Miguel Servet Program(C.H.U.A Coruña and ISCIII)(Tomás M)the CONACyT grant number 441393/269132(Mandujano-Tinoco EA)and the Biotechnology Endowed Chair at the Pennsylvania State University.
文摘Quorum sensing(QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed.
基金Supported by Council of Scientific and Industrial Research(CSIR),Government of India
文摘Objective:To examine the anti-bacterial activity of leaf extracts of Morus alba L.(Moraceae)and Piper betel L.(Piperaceae),and seed extracts of Bombax ceiba L.(Borabacaceae).Methods:We have partially purified plant extracts by solvent extraction method,and evaluated the effect of individual fractions on bacterial growth using Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Staphylococcus aureus(S.aureus) bacterial strains.Results:Compared with Morus and Bombax fractions,Piper fractions showed significant growth inhibition on all the three types of bacteria studied.The EtOAc-hexane fractions of Piper leaves exhibited significant antibacterial activity with minimum inhibitory concentrations(MIC) of 50 μg/mL culture against both gram-positive and gram-negative bacteria.The EtOAc-fractions Ⅰ,Ⅱ,and Ⅳ inhibited bacterial colony formation on soft agar in addition to growth inhibition.A combination treatment of piper fractions with ampicillin resulted in significant growth inhibition in E.coli and P.aeruginosa,and combination with anticancer drug geldanamycin(2 μg/mL) showed selective growth inhibition against P.aeruginosa and S.aureus.Three major compounds,i.e.,eugenol,3-hexene-ol and stigmasterol,were primarily identified from Piper betel leaf extractions.Among the individual compounds,eugenol treatment showed improved growth inhibition compared with stigmasterol and 3-hexene-ol.Conclusions:We are reporting potential anti-bacterial compounds from Piper betel against both gram-positive and gram-negative bacteria either alone or in combination with drug treatment.
文摘There are numerous reports regarding the antimicrobial effects of herbal extracts on bacteria and fungi. We have prepared water extracts of Wild Leek （A. ampeloprasum var. porrum）, Kurrat （A. ampeloprasum var. kurrat） and Elephant Garlic （A. ampeloprasum var. ampeloprasum） by rotary vacuum distillation. As a result, the extraction was carried out in 40 ℃ thus omitting any risk of loss of anti-bacterial activity due to high temperatures reported in prior similar studies [ 1]. The five bacteria Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus were tested against the extracts. While some extent of inhibition was observed when the bacteria were cultured in presence of the leek and kurrat extracts, elephant garlic was determined to possess an extreme inhibitory quality against all the aforementioned bacteria, completely inhibiting the growth of the bacteria after 24 hrs of culture in exposure to the extract. We propose that elephant garlic extract could be an effective alternative to chemical antibiotic treatments and disinfectants in hospital and other settings in which infections are common.
