The rapid emergence and spread of colistin-resistant gram-negative bacteria has raised worldwide public health concerns,and phosphoethanolamine(PEtn)transferase modification-mediated colistin resistance has been widel...The rapid emergence and spread of colistin-resistant gram-negative bacteria has raised worldwide public health concerns,and phosphoethanolamine(PEtn)transferase modification-mediated colistin resistance has been widely documented in multiple gram-negative bacterial species.However,whether such a mechanism exists in the zoonotic pathogen Pasteurella multocida is still unknown.Recently,a novel PEtn transferase,PetL,was identified in P.multo-cida,but whether it is associated with colistin resistance remains to be elucidated.In this study,we found that PetL in P.multocida(PetL^(PM))exhibited structural characteristics similar to those of the mobile-colistin-resistant(MCR)protein and the PEtn transferase characterized in Neisseria meningitidis.The transformation of petLPM into E.coli or K.pneumoniae changed the phenotype of several tested strains from colistin sensitive to colistin resistant.Deletion of this gene decreased the colistin minimum inhibitory concentration(MIC)of P.multocida by 64-fold.Our extensive analysis by MALDI-TOF-MS demonstrated that PetLPM participated in the modification of bacterial lipopolysaccharide(LPS)-lipid A.Deletion of petL^(PM) led to an increase in membrane charge but a decrease in cell-surface hydrophobicity and cell permeability in P.multocida.The present study is the first to report the presence of PEtn transferase-mediated colistin resistance in the zoonotic pathogen P.multocida.展开更多
Pasteurellosis is the most prevalent, extremely contagious bacterial disease among domestic rabbits and is considered the leading cause of deaths in rabbits, resulting in enormous economic losses to the rabbit industr...Pasteurellosis is the most prevalent, extremely contagious bacterial disease among domestic rabbits and is considered the leading cause of deaths in rabbits, resulting in enormous economic losses to the rabbit industry. Screening for bacterial agents causing mortalities in rabbits revealed the presence of Enterobacteriacae species in approximately 42% of studied cases, with E. coli the most commonly isolated organism. The present study was designed to evaluate the immune response of rabbits vaccinated with a locally prepared, combined inactivated vaccine of Pasteurella multocida and E. coli, adjuvanated with Montanide ISA70. A total of 370 rabbits, aged 2 - 3 weeks, were divided into four groups: (G1) vaccinated with a polyvalent P. multocida vaccine, (G2) vaccinated with a polyvalent E. coli vaccine, (G3) vaccinated with a combined inactivated Montanide ISA70 vaccine of P. multocida and E. coli, and (G4) kept as a non-vaccinated control group. All rabbits received two doses of 0.5 ml of the prepared vaccines, administered one month apart, and were then challenged with virulent strains of P. multocida and E. coli three weeks after the second vaccination. The prepared vaccines were evaluated by determining humoral immunity using indirect haemagglutination (IHA) test and ELISA. The potency of the vaccines was assessed through challenge and determination of LD50. Experimental findings on the prepared polyvalent combined inactivated P. multocida and E. coli vaccine indicated that it is a potent vaccine, producing the highest antibody titers and a 90% protection rate against challenges with virulent strains of P. multocida type A, D2, and E. coli types O157, O151 and O125. Thus, this vaccine is promising in addressing both P. multocida and E. coli problems in rabbits, farms, providing significant protection, and we recommend its commercial production to help rabbit producers control these two major bacterial infections.展开更多
基金supported in part by the Hubei Provincial Natural Science Foundation of China(grant no.2023AFA094)the Yingzi Tech&Huazhong Agricultural University Intelligent Research Institute of Food Health(No.IRIFH202209)+1 种基金Fundamental Research Funds for the Central Universities(Project 2662023PY005)the Hubei Hongshan Laboratory&Huazhong Agricultural University Start-up Fund.
文摘The rapid emergence and spread of colistin-resistant gram-negative bacteria has raised worldwide public health concerns,and phosphoethanolamine(PEtn)transferase modification-mediated colistin resistance has been widely documented in multiple gram-negative bacterial species.However,whether such a mechanism exists in the zoonotic pathogen Pasteurella multocida is still unknown.Recently,a novel PEtn transferase,PetL,was identified in P.multo-cida,but whether it is associated with colistin resistance remains to be elucidated.In this study,we found that PetL in P.multocida(PetL^(PM))exhibited structural characteristics similar to those of the mobile-colistin-resistant(MCR)protein and the PEtn transferase characterized in Neisseria meningitidis.The transformation of petLPM into E.coli or K.pneumoniae changed the phenotype of several tested strains from colistin sensitive to colistin resistant.Deletion of this gene decreased the colistin minimum inhibitory concentration(MIC)of P.multocida by 64-fold.Our extensive analysis by MALDI-TOF-MS demonstrated that PetLPM participated in the modification of bacterial lipopolysaccharide(LPS)-lipid A.Deletion of petL^(PM) led to an increase in membrane charge but a decrease in cell-surface hydrophobicity and cell permeability in P.multocida.The present study is the first to report the presence of PEtn transferase-mediated colistin resistance in the zoonotic pathogen P.multocida.
文摘Pasteurellosis is the most prevalent, extremely contagious bacterial disease among domestic rabbits and is considered the leading cause of deaths in rabbits, resulting in enormous economic losses to the rabbit industry. Screening for bacterial agents causing mortalities in rabbits revealed the presence of Enterobacteriacae species in approximately 42% of studied cases, with E. coli the most commonly isolated organism. The present study was designed to evaluate the immune response of rabbits vaccinated with a locally prepared, combined inactivated vaccine of Pasteurella multocida and E. coli, adjuvanated with Montanide ISA70. A total of 370 rabbits, aged 2 - 3 weeks, were divided into four groups: (G1) vaccinated with a polyvalent P. multocida vaccine, (G2) vaccinated with a polyvalent E. coli vaccine, (G3) vaccinated with a combined inactivated Montanide ISA70 vaccine of P. multocida and E. coli, and (G4) kept as a non-vaccinated control group. All rabbits received two doses of 0.5 ml of the prepared vaccines, administered one month apart, and were then challenged with virulent strains of P. multocida and E. coli three weeks after the second vaccination. The prepared vaccines were evaluated by determining humoral immunity using indirect haemagglutination (IHA) test and ELISA. The potency of the vaccines was assessed through challenge and determination of LD50. Experimental findings on the prepared polyvalent combined inactivated P. multocida and E. coli vaccine indicated that it is a potent vaccine, producing the highest antibody titers and a 90% protection rate against challenges with virulent strains of P. multocida type A, D2, and E. coli types O157, O151 and O125. Thus, this vaccine is promising in addressing both P. multocida and E. coli problems in rabbits, farms, providing significant protection, and we recommend its commercial production to help rabbit producers control these two major bacterial infections.
