Pasteurella multocida is a leading cause of respiratory disorders in pigs.This study was designed to understand the genotypical and antimicrobial resistant characteristics of P.multocida from pigs in China.To achieve ...Pasteurella multocida is a leading cause of respiratory disorders in pigs.This study was designed to understand the genotypical and antimicrobial resistant characteristics of P.multocida from pigs in China.To achieve this,we briefly investigated 158 P.multocida isolates from pigs with respiratory disorders in China between 2019 and 2020.Genotyping through multiplex PCR assays assigned these 158 isolates into capsular genotypes A(60.13%,95/158),D(35.44%,56/158),F(4.43%,7/158),and/or lipopolysaccharide(LPS)genotypes L3(28.48%,45/158)and L6(66.46%,105/158).In addition,eight isolates(5.06%,8/158)were found to be nontypable using the LPS genotyping method.When combining the capsular genotypes and the LPS genotypes,D:L6(34.81%,55/158)and A:L6(31.65%,50/158)were the predominant genotypes,followed by A:L3(24.05%,38/158).PCR detection of virulence factor-encoding genes showed that over 80%of the isolates were positive for exbB,tonB,exbD,ompH,ptfA,fimA,sodA,sodC,fur,ompA,oma87,plpB,hsf-2,nanH and hgbB,suggesting the presence of these genes were broad characteristics of P.multocida.We also found approximately 63.92%(101/158),51.27%(81/158),8.86%(14/158),7.59%(12/158),3.16%(5/158),0.63%(1/158),and 0.63%(1/158)of the isolates grew well in media with the presence of colistin(4μg/mL),tetracycline(16μg/mL),tigecycline(1μg/mL),ampicillin(32μg/mL),chloramphenicol(32μg/mL),cefepime(16μg/mL),and ciprofloxacin(1μg/mL),respectively.This study contributes to the understanding of genotypes and antimicrobial resistance profile of P.multocida currently circulation in pigs of China.展开更多
Objective: To evaluate the effects of Pasteurella multocida(P. multocida) vaccines on the expression and release of antibodies, interleukin(IL)-6 and IL-12 by serum. Methods: Balb/c mice were immunized with two formal...Objective: To evaluate the effects of Pasteurella multocida(P. multocida) vaccines on the expression and release of antibodies, interleukin(IL)-6 and IL-12 by serum. Methods: Balb/c mice were immunized with two formalin and iron inactivated vaccine doses within 2 weeks. The vaccines were adjuvant with P. multocida A strain, P. multocida B strain and Salmonella typhimurium bacterial DNA(AbDNA, BbDNA and SbDNA for short, respectively). The animals were challenged 4 weeks after immunization. Blood of mice was collected to detect the change of specific antibody, IL-6, and IL-12 using ELISA. Results: The specific antibody and interleukins in the immunized group increased significantly compared to the control mice after vaccination and challenge(P<0.05). The highest release of these cytokines was obtained by P.multocida inactivated with iron and adjuvant with AbDNA at a concentration of 25 μg/mL. The antibody titer peak was 0.447 in mice vaccinated with iron-killed whole-cell antigen adjunct with AbDNA. The time-courses of release showed that bacterial DNA was able to stimulate IL-6 and IL-12 production more than alum(P<0.05). Conclusions: Our findings introduce that bacterial DNA is capable of releasing an immunological response with several cytokines.These indicate that bacterial DNA entrapped with killed P. multocida antigen is a new and effective adjuvant to enhance specific immunity and resistance of animal against the infectious pathogen, which could simplify the development of highly promising strong adjuvant.展开更多
In this study,55 suspected pasteurellosis clinical cases from different provinces of Morocco were investigated.Molecular analysis revealed that 47%of samples were positive for Pasteurella multocida,all typed as serogr...In this study,55 suspected pasteurellosis clinical cases from different provinces of Morocco were investigated.Molecular analysis revealed that 47%of samples were positive for Pasteurella multocida,all typed as serogroup A,and 11%positive for Mannheimia heamolytica.Eight isolates were recovered from 26 P.multocida positive samples,and characterized by biochemical and molecular typing methods.Among these isolates,two strains(S13 and S14)were selected for genes(RNA16S and rpoB)sequence analysis and virulence study in mice,guinea pigs and sheep.Phylogeny study showed similarities of both S14 and S13 isolates with strains from other species.In laboratory animals,the strain S14 was more virulent than S13 and induced severe illness in sheep.The high mortality of infected mice suggests that this model may represent an alternative for testing pathogenicity and vaccine efficacy.展开更多
<strong>Background:</strong> This work evaluated the capacity of a dry emulsion as a carrier of viable microorganisms with potential use as prophylaxis of infectious diseases. <strong>Methods:</st...<strong>Background:</strong> This work evaluated the capacity of a dry emulsion as a carrier of viable microorganisms with potential use as prophylaxis of infectious diseases. <strong>Methods:</strong> The aqueous phase containing <em>P. multocida </em>not viable in PBS was emulsified in mineral oil to obtain a w/o emulsion. The microorganisms remained stable and only in two cases (n = 6) did the bacterial concentration decrease. Scanning Electron Microscopy (SEM) revealed a structure of a system with the organized association of particles with cubic symmetry. Using two <em>ex vivo </em>bioadhesion systems, it was demonstrated that the disperse-adsorbed system is capable of adhering to the intestinal mucosa and remains adhered for long periods of time. <strong>Results: </strong>The no viability of the bacteria in the dry emulsion and the possibility of controlled release were confirmed. <em>In vivo </em>trial was conducted in pigs. It was possible to locate the emulsion and the bacteria attached to the gut of the living animal. An ELISA kit was used to monitor the mean antibody titer of treated pigs over a 2-week period, and a classic primary response curve occurred when the titer was plotted against time. <strong>Conclusion: </strong>We propose the disperse-adsorbed system as an alternative to commonly used vehicles for immunogens in the oral vaccines.展开更多
Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera, bovine hemorrhagic septicemia, enzoonotic pneumonia and swine atropic rhinitis. Two filamentous hemagglutinin gen...Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera, bovine hemorrhagic septicemia, enzoonotic pneumonia and swine atropic rhinitis. Two filamentous hemagglutinin genes, fhaB1 and fhaB2, are the potential virulence factors. In this study, an inactivation fhaB1 mutant of P. multocida in avian strain C48-102 was constructed by a kanamycin-resistance cassette. The virulence of the fhaB1 mutant and the wild type strain was assessed in chickens by intranasal and intramuscular challenge. The inactivation of fhaB1 resulted in a high degree of attenuation when the chickens were challenged intranasally and a lesser degree when challenged intramuscularly. The fhaB1 mutant and the wild type strain were investigated their sensitivity to the antibody-dependent classical complement-mediated killing pathway in 90% convalescent chicken serum. The fhaB1 mutant was serum sensitive as the viability has reduced between untreated serum and heat inactivated chicken serum(P<0.007). These results confirmed that FhaB1 played the critical roles in the bacterial pathogenesis and further studies were needed to investigate the mechanism which caused reduced virulence of the fhaB1 mutant.展开更多
[Objective] To develop multiplex-PCR for diagnosis of mixed infection caused by Pasteurella multocida (PM),Haemophilus parasuis (HPS) and Actinbacillus pleuropneumoniae (App).[Method] PCR method was developed to detec...[Objective] To develop multiplex-PCR for diagnosis of mixed infection caused by Pasteurella multocida (PM),Haemophilus parasuis (HPS) and Actinbacillus pleuropneumoniae (App).[Method] PCR method was developed to detect single infection caused by PM,HPS or App.The conditions of amplification and primers were optimized,and the multiple-PCR was developed to detect mixed infection of PM,HPS and App.[Result] A 457-bp band,a 821-bp band and a 342-bp band were simultaneously amplified in the one PCR reaction system.The method had high sensitivity and specificity.[Conclusion] The multiple-PCR is successfully developed and can be used for differential diagnosis of PM,HPS and App.展开更多
Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that...Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that provoke weight loss in animals or death. In the PRDC multiple pathogens (bacteria and/or viruses) work in combination to induce this respiratory disease. Within this complex, Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae are the main bacterial pathogens involved in great economic losses to the swine industry. The aim of this work was to estimate the presence of A. pleuropneumoniae, S. suis, P. multocida, B. bronchiseptica, H. parasuis and M. hyopneumoniae in the upper respiratory tract of pigs in representative swine farms inAguascalientes,Mexico, using PCR technique. The study was performed in 14 swine farms. We obtained a total of 212 nasal swabs. Near 20% of samples were positive for A. pleuropneumoniae (located in the 79% of farms);17% were positive for S. suis (in 86% of farms), of these, 3% were S. suis serovar 2;30% were positive for H. parasuis (93% of farms);23% of the samples to P. multocida (in 79% of farms);and 19% to M. hyopneumoniae (in 64% of farms). B. bronchiseptica was not detected in this study. The results obtained show that bacterial pathogens of PRDC were present in the upper respiratory tract of pigs in all farms studied;therefore, these pathogens are widely disseminated in pig farms of Aguascalientes, Mexico.展开更多
Objective:To characterize Pasteurella isolated from backyard chickens using whole cell protein lysate profiles and random amplified polymorphic DNA(RAPD)techniques to show their genetic relationship because Pasteurcll...Objective:To characterize Pasteurella isolated from backyard chickens using whole cell protein lysate profiles and random amplified polymorphic DNA(RAPD)techniques to show their genetic relationship because Pasteurclla multocida(P.multocida)is an important cause of fatal infections in backyard chickens.Methods:Twenty one P.multocida isolates were recovered previously from clinical cases of fowl cholera belonging to individual owners and phenotypically analysed using biochemical tests and serotyping were used far the genetic characterization.Results:Phylogenetic study based on both methods revealed that the recovered population of P.multocida isolated from backyard chickens differs markedly,constituting a well-separated cluster and appearance of 3 distinguishing lineages with greater discrimination shown by RAPDPCR that resulted in two suclusters in cluster A and three subclusters in cluster B and were related greatly with capsular serogroups for the examined strains.The whole cell protein revealed the presence of dominant protein bands at approximately 41 and 61 kDa in all of the examined isolates that may be a virulent proteins share in the increasing of its pathogenicity.Clear distinctive bands ranged from 123 to 1534 bp.Conclusions:Based on the previous findings,there are three spreading clusters that may indicate the association of a small number of P.multocida variants with the majority of cases suggesting that certain clones of P.multocida are able to colonue the examined backyard chickens.Also,the ease and rapidity of RAPD-PCR support the use of this technique as alternative to the more labour-intensive SDS-PACE system for strain differentiation and epidemiological studies of avian P.multocida.Further application of RAPD technology to the examination of avian cholera outbreaks in commercially available flocks may facilitate more effective management of this disease by providing the potential to investigate correlations of P.multocida genotypes,to identify affiliations between bird types and bacterial genotypes,and to elucidate the role of specific bird species in disease transmission.展开更多
Background:Pasteurella multocida is an important and old zoonotic pathogen worldwide which has an impressive host spectrum including numerous domestic and wild animals as well as birds,causing specific diseases or out...Background:Pasteurella multocida is an important and old zoonotic pathogen worldwide which has an impressive host spectrum including numerous domestic and wild animals as well as birds,causing specific diseases or outbreak with great economic impact.It has never been reported that P.multocida can cause an epidemic in wild rodents.In June 5–17,2016,more than 1000 rodent deaths of an unknown cause quickly spread in the PuEr City,Yunnan province,southwestern China.Methods:The rodents in affected areas and outside of the epidemic areas were collected and screened for possible known pathogens including Yersinia pestis,rabies virus and hantavirus as well as other bacteria.The possible bacterial pathogens were isolated both by culture medium and by mouse inoculation in parallel.The isolates were identified by the Vitek GNI card and PCR assays for 16S rRNA genes.The pathogen strains were selected for whole genome sequencing analysis.Results:A total of 123 rodents were collected from 25 sample sites at affected area,among of which,all 119 dead rodents were negative for the pathogen under consideration except P.multocida,and all four live rodents were negative for P.multocida.In addition,480 rodents collected from other 23 counties outside of the epidemic area in Yunnan were negative for with P.multocida.A total of 14 strains of P.multocida(six directly isolated from the field rodents and eight from the experimental mice that were injected with the organ substrates from the dead rodents)belonged to serogroup A and serogroup F represented by 9 N and 20 N were identified in these epidemic areas.Whole genome sequencing revealed that the serogroup F strain shared 99%similarity to P.multocida Pm70 from chicken,but contained a 50 k bp insertion sequence.The serogroup A strain shared 95%similarity to P.multocida FDAARGOS_385 from a human patient,but contained four large structural differences.Histological abnormalities were identified in the livers,lungs,hearts and brains of the inoculated mice.Conclusions:The simultaneous occurrence of both serotypes of P.multocida may have caused this sudden onset of mortality across the local rodent population in Yunnan Province,China.Further attention should be paid to this old bacterium in the world.展开更多
P asteurella multocida (P. multocida), a Gram-negative pathogen, is mainly associated with animal infections. Human P. multocida infections are occasionally encountered and most human cases are due to the animal expos...P asteurella multocida (P. multocida), a Gram-negative pathogen, is mainly associated with animal infections. Human P. multocida infections are occasionally encountered and most human cases are due to the animal exposure or contact, especially due to cat bites. 1 In China, P. multocida infections are rarely described. CASE REPORT A 50-year old woman was sent to the Emergency Department of West China Hospital on June 25, 2004, due to the complain of an onset of pain, erythema, bleeding, and swelling at a wound on the right leg, caused by a pet cat bite 11 hours ago. She was diagnosed as having a wound infection and received intravenous penicillin G 4 million U/day. One day later, though the bleeding was ceased, she felt worse. Then, she was admitted to the Department of Infectious Diseases. She has no fever nor other systemic symptoms when she was admitted. On examination, three close, small and deep holes were found on the right leg near the ankle. Around the holes, the skin and soft tissue were red swelling and tenderness with a high skin temperature. Little pus was presented when the wound was crushed. Regional lymphadenopathy in right groin was found. No dyskinesia and tenderness of the ankle joint was found. Examination of her respiratory, cardiovascular, and gastrointestinal systems was unremarkable. Initial blood routine examination for her revealed: haemoglobin 12.5 g/dl; white blood cell count 7×10 9/L (neutrophils 4.48, lymphocytes 2.45); platelet, 184×10 9/L. But the white cell count increased to 11.2×10 9/L (neutrophils 8.52, lymphocytes 2.58) on the next day. Routine biochemical examination for her revealed normality.展开更多
基金This work was supported in part by the China Postdoctoral Foundation(grant 2020 T130232)the Key Laboratory of Livestock Disease Prevention of Guangdong Province and the Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province,Ministry of Agriculture and Rural Affairs,China(grant YDWS1901)Hubei Provincial Key R&D program.The funder had no role in the study design,data collection,data analysis,data interpretation,or writing of the manuscript.
文摘Pasteurella multocida is a leading cause of respiratory disorders in pigs.This study was designed to understand the genotypical and antimicrobial resistant characteristics of P.multocida from pigs in China.To achieve this,we briefly investigated 158 P.multocida isolates from pigs with respiratory disorders in China between 2019 and 2020.Genotyping through multiplex PCR assays assigned these 158 isolates into capsular genotypes A(60.13%,95/158),D(35.44%,56/158),F(4.43%,7/158),and/or lipopolysaccharide(LPS)genotypes L3(28.48%,45/158)and L6(66.46%,105/158).In addition,eight isolates(5.06%,8/158)were found to be nontypable using the LPS genotyping method.When combining the capsular genotypes and the LPS genotypes,D:L6(34.81%,55/158)and A:L6(31.65%,50/158)were the predominant genotypes,followed by A:L3(24.05%,38/158).PCR detection of virulence factor-encoding genes showed that over 80%of the isolates were positive for exbB,tonB,exbD,ompH,ptfA,fimA,sodA,sodC,fur,ompA,oma87,plpB,hsf-2,nanH and hgbB,suggesting the presence of these genes were broad characteristics of P.multocida.We also found approximately 63.92%(101/158),51.27%(81/158),8.86%(14/158),7.59%(12/158),3.16%(5/158),0.63%(1/158),and 0.63%(1/158)of the isolates grew well in media with the presence of colistin(4μg/mL),tetracycline(16μg/mL),tigecycline(1μg/mL),ampicillin(32μg/mL),chloramphenicol(32μg/mL),cefepime(16μg/mL),and ciprofloxacin(1μg/mL),respectively.This study contributes to the understanding of genotypes and antimicrobial resistance profile of P.multocida currently circulation in pigs of China.
基金part of the project:Study on immune response pattern of cattle vaccinated by Razi pasteurellosis vaccine(Project number:12-18-18-9458-94014)
文摘Objective: To evaluate the effects of Pasteurella multocida(P. multocida) vaccines on the expression and release of antibodies, interleukin(IL)-6 and IL-12 by serum. Methods: Balb/c mice were immunized with two formalin and iron inactivated vaccine doses within 2 weeks. The vaccines were adjuvant with P. multocida A strain, P. multocida B strain and Salmonella typhimurium bacterial DNA(AbDNA, BbDNA and SbDNA for short, respectively). The animals were challenged 4 weeks after immunization. Blood of mice was collected to detect the change of specific antibody, IL-6, and IL-12 using ELISA. Results: The specific antibody and interleukins in the immunized group increased significantly compared to the control mice after vaccination and challenge(P<0.05). The highest release of these cytokines was obtained by P.multocida inactivated with iron and adjuvant with AbDNA at a concentration of 25 μg/mL. The antibody titer peak was 0.447 in mice vaccinated with iron-killed whole-cell antigen adjunct with AbDNA. The time-courses of release showed that bacterial DNA was able to stimulate IL-6 and IL-12 production more than alum(P<0.05). Conclusions: Our findings introduce that bacterial DNA is capable of releasing an immunological response with several cytokines.These indicate that bacterial DNA entrapped with killed P. multocida antigen is a new and effective adjuvant to enhance specific immunity and resistance of animal against the infectious pathogen, which could simplify the development of highly promising strong adjuvant.
文摘In this study,55 suspected pasteurellosis clinical cases from different provinces of Morocco were investigated.Molecular analysis revealed that 47%of samples were positive for Pasteurella multocida,all typed as serogroup A,and 11%positive for Mannheimia heamolytica.Eight isolates were recovered from 26 P.multocida positive samples,and characterized by biochemical and molecular typing methods.Among these isolates,two strains(S13 and S14)were selected for genes(RNA16S and rpoB)sequence analysis and virulence study in mice,guinea pigs and sheep.Phylogeny study showed similarities of both S14 and S13 isolates with strains from other species.In laboratory animals,the strain S14 was more virulent than S13 and induced severe illness in sheep.The high mortality of infected mice suggests that this model may represent an alternative for testing pathogenicity and vaccine efficacy.
文摘<strong>Background:</strong> This work evaluated the capacity of a dry emulsion as a carrier of viable microorganisms with potential use as prophylaxis of infectious diseases. <strong>Methods:</strong> The aqueous phase containing <em>P. multocida </em>not viable in PBS was emulsified in mineral oil to obtain a w/o emulsion. The microorganisms remained stable and only in two cases (n = 6) did the bacterial concentration decrease. Scanning Electron Microscopy (SEM) revealed a structure of a system with the organized association of particles with cubic symmetry. Using two <em>ex vivo </em>bioadhesion systems, it was demonstrated that the disperse-adsorbed system is capable of adhering to the intestinal mucosa and remains adhered for long periods of time. <strong>Results: </strong>The no viability of the bacteria in the dry emulsion and the possibility of controlled release were confirmed. <em>In vivo </em>trial was conducted in pigs. It was possible to locate the emulsion and the bacteria attached to the gut of the living animal. An ELISA kit was used to monitor the mean antibody titer of treated pigs over a 2-week period, and a classic primary response curve occurred when the titer was plotted against time. <strong>Conclusion: </strong>We propose the disperse-adsorbed system as an alternative to commonly used vehicles for immunogens in the oral vaccines.
基金supported by the National Natural Science Foundation of China(31302109)
文摘Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera, bovine hemorrhagic septicemia, enzoonotic pneumonia and swine atropic rhinitis. Two filamentous hemagglutinin genes, fhaB1 and fhaB2, are the potential virulence factors. In this study, an inactivation fhaB1 mutant of P. multocida in avian strain C48-102 was constructed by a kanamycin-resistance cassette. The virulence of the fhaB1 mutant and the wild type strain was assessed in chickens by intranasal and intramuscular challenge. The inactivation of fhaB1 resulted in a high degree of attenuation when the chickens were challenged intranasally and a lesser degree when challenged intramuscularly. The fhaB1 mutant and the wild type strain were investigated their sensitivity to the antibody-dependent classical complement-mediated killing pathway in 90% convalescent chicken serum. The fhaB1 mutant was serum sensitive as the viability has reduced between untreated serum and heat inactivated chicken serum(P<0.007). These results confirmed that FhaB1 played the critical roles in the bacterial pathogenesis and further studies were needed to investigate the mechanism which caused reduced virulence of the fhaB1 mutant.
基金funded by the subproject of National Key Technology R&D Program (2006BAD06A01 and 2006BAD06A12)Basic Work of National Science and Technology Special Plan (2008FY210200)
文摘[Objective] To develop multiplex-PCR for diagnosis of mixed infection caused by Pasteurella multocida (PM),Haemophilus parasuis (HPS) and Actinbacillus pleuropneumoniae (App).[Method] PCR method was developed to detect single infection caused by PM,HPS or App.The conditions of amplification and primers were optimized,and the multiple-PCR was developed to detect mixed infection of PM,HPS and App.[Result] A 457-bp band,a 821-bp band and a 342-bp band were simultaneously amplified in the one PCR reaction system.The method had high sensitivity and specificity.[Conclusion] The multiple-PCR is successfully developed and can be used for differential diagnosis of PM,HPS and App.
文摘Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that provoke weight loss in animals or death. In the PRDC multiple pathogens (bacteria and/or viruses) work in combination to induce this respiratory disease. Within this complex, Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae are the main bacterial pathogens involved in great economic losses to the swine industry. The aim of this work was to estimate the presence of A. pleuropneumoniae, S. suis, P. multocida, B. bronchiseptica, H. parasuis and M. hyopneumoniae in the upper respiratory tract of pigs in representative swine farms inAguascalientes,Mexico, using PCR technique. The study was performed in 14 swine farms. We obtained a total of 212 nasal swabs. Near 20% of samples were positive for A. pleuropneumoniae (located in the 79% of farms);17% were positive for S. suis (in 86% of farms), of these, 3% were S. suis serovar 2;30% were positive for H. parasuis (93% of farms);23% of the samples to P. multocida (in 79% of farms);and 19% to M. hyopneumoniae (in 64% of farms). B. bronchiseptica was not detected in this study. The results obtained show that bacterial pathogens of PRDC were present in the upper respiratory tract of pigs in all farms studied;therefore, these pathogens are widely disseminated in pig farms of Aguascalientes, Mexico.
基金Supported by Regular goveromental annual fund every Fiscal year from Assiut university(Grant No.9/020/08595/0)
文摘Objective:To characterize Pasteurella isolated from backyard chickens using whole cell protein lysate profiles and random amplified polymorphic DNA(RAPD)techniques to show their genetic relationship because Pasteurclla multocida(P.multocida)is an important cause of fatal infections in backyard chickens.Methods:Twenty one P.multocida isolates were recovered previously from clinical cases of fowl cholera belonging to individual owners and phenotypically analysed using biochemical tests and serotyping were used far the genetic characterization.Results:Phylogenetic study based on both methods revealed that the recovered population of P.multocida isolated from backyard chickens differs markedly,constituting a well-separated cluster and appearance of 3 distinguishing lineages with greater discrimination shown by RAPDPCR that resulted in two suclusters in cluster A and three subclusters in cluster B and were related greatly with capsular serogroups for the examined strains.The whole cell protein revealed the presence of dominant protein bands at approximately 41 and 61 kDa in all of the examined isolates that may be a virulent proteins share in the increasing of its pathogenicity.Clear distinctive bands ranged from 123 to 1534 bp.Conclusions:Based on the previous findings,there are three spreading clusters that may indicate the association of a small number of P.multocida variants with the majority of cases suggesting that certain clones of P.multocida are able to colonue the examined backyard chickens.Also,the ease and rapidity of RAPD-PCR support the use of this technique as alternative to the more labour-intensive SDS-PACE system for strain differentiation and epidemiological studies of avian P.multocida.Further application of RAPD technology to the examination of avian cholera outbreaks in commercially available flocks may facilitate more effective management of this disease by providing the potential to investigate correlations of P.multocida genotypes,to identify affiliations between bird types and bacterial genotypes,and to elucidate the role of specific bird species in disease transmission.
基金This study was funded by the State Key Research Development Program of China(2016YFC1201902,2016YFC1200301)the Natural Science Foundation of China(81621005,81773492,81760607,81360413)the Program of Cultivation of Technologically Innovative Talents of Yunnan(2014HB093).
文摘Background:Pasteurella multocida is an important and old zoonotic pathogen worldwide which has an impressive host spectrum including numerous domestic and wild animals as well as birds,causing specific diseases or outbreak with great economic impact.It has never been reported that P.multocida can cause an epidemic in wild rodents.In June 5–17,2016,more than 1000 rodent deaths of an unknown cause quickly spread in the PuEr City,Yunnan province,southwestern China.Methods:The rodents in affected areas and outside of the epidemic areas were collected and screened for possible known pathogens including Yersinia pestis,rabies virus and hantavirus as well as other bacteria.The possible bacterial pathogens were isolated both by culture medium and by mouse inoculation in parallel.The isolates were identified by the Vitek GNI card and PCR assays for 16S rRNA genes.The pathogen strains were selected for whole genome sequencing analysis.Results:A total of 123 rodents were collected from 25 sample sites at affected area,among of which,all 119 dead rodents were negative for the pathogen under consideration except P.multocida,and all four live rodents were negative for P.multocida.In addition,480 rodents collected from other 23 counties outside of the epidemic area in Yunnan were negative for with P.multocida.A total of 14 strains of P.multocida(six directly isolated from the field rodents and eight from the experimental mice that were injected with the organ substrates from the dead rodents)belonged to serogroup A and serogroup F represented by 9 N and 20 N were identified in these epidemic areas.Whole genome sequencing revealed that the serogroup F strain shared 99%similarity to P.multocida Pm70 from chicken,but contained a 50 k bp insertion sequence.The serogroup A strain shared 95%similarity to P.multocida FDAARGOS_385 from a human patient,but contained four large structural differences.Histological abnormalities were identified in the livers,lungs,hearts and brains of the inoculated mice.Conclusions:The simultaneous occurrence of both serotypes of P.multocida may have caused this sudden onset of mortality across the local rodent population in Yunnan Province,China.Further attention should be paid to this old bacterium in the world.
文摘P asteurella multocida (P. multocida), a Gram-negative pathogen, is mainly associated with animal infections. Human P. multocida infections are occasionally encountered and most human cases are due to the animal exposure or contact, especially due to cat bites. 1 In China, P. multocida infections are rarely described. CASE REPORT A 50-year old woman was sent to the Emergency Department of West China Hospital on June 25, 2004, due to the complain of an onset of pain, erythema, bleeding, and swelling at a wound on the right leg, caused by a pet cat bite 11 hours ago. She was diagnosed as having a wound infection and received intravenous penicillin G 4 million U/day. One day later, though the bleeding was ceased, she felt worse. Then, she was admitted to the Department of Infectious Diseases. She has no fever nor other systemic symptoms when she was admitted. On examination, three close, small and deep holes were found on the right leg near the ankle. Around the holes, the skin and soft tissue were red swelling and tenderness with a high skin temperature. Little pus was presented when the wound was crushed. Regional lymphadenopathy in right groin was found. No dyskinesia and tenderness of the ankle joint was found. Examination of her respiratory, cardiovascular, and gastrointestinal systems was unremarkable. Initial blood routine examination for her revealed: haemoglobin 12.5 g/dl; white blood cell count 7×10 9/L (neutrophils 4.48, lymphocytes 2.45); platelet, 184×10 9/L. But the white cell count increased to 11.2×10 9/L (neutrophils 8.52, lymphocytes 2.58) on the next day. Routine biochemical examination for her revealed normality.
