Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyp...Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyperinvasive ST-4821 serogroup C clone associated with this outbreak. Methods The cases were described based on the clinical symptoms and laboratory results. Pharyngeal swabs were cultured for N. meningitidis from men in the jail. Meningococcal isolates were identified by serogrouping, pulsed-field gel electrophoresis （PFGE） and multilocus sequence typing （MLST）, respectively. Four hundred and sixteen serogroup C N. meningitidis strains were collected from 27 provinces between 2003 and 2010 for a nationwide survey and analyzed by PFGE and MLST. Results Three persons in a jail system were infected with invasive N. meningitidis serogroup C. All isolates tested had matching PFGE patterns and belonged to the multilocus sequence type （ST） 4821 clonal complex. All 47 N. meningitidis strains were identified from the pharyngeal swabs of 166 peoples in the jail, and 26 of them belonged to ST-4821 serogroup C clone, and 90.14% （375/416） serogroup C strains identified in the nationwide survey belonged to the ST-4821 complex. The ST-4821 serogroup C clone was spread nationwide, distributed in 24 provinces, especially in eastern provinces between 2003 and 2010. Conclusion Endemic transmission and carriage rate of ST-4821 serogroup C clone are high in this jail system. The ST-4821 serogroup C clone is spreading in China and nationwide distributed despite the existence of some effective vaccines.展开更多
A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in rece...A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in recent years. The percentage of isolation was 69.1%. There are 67 serogroups each with 1-2 isolates distributed in different regions, and some of these regions had the preponderant serogroups. Antimicrobial-resistance （AR） of E. coli was so severe that the majority were multi-AR. Fifty percent strains were resistant to 10-19 antimicrobial drugs. Overall, the isolates represented resistance to nalidixic acid （88.1%）, tetracycline （85.7%）, sulfamethoxazole （81.0%）, trimethoprim-sulfamethpxazole （77.1%）, ampicillin （76.2%）, amoxilline （74.3%）, streplomycin （66.2%）, fluoroquinolones （57.1-66.7%）, chloramphenicol （52.9%）, gentamicin （39.0%）, and kanamycin （36.2%）. The isolates were sensitive to cefalexin, amoxilline-clavulanic acid, amikacin, and florfenicol with an AR rate of 0-19,5% only, The results showed that the AR was more severe in chicken farms in which the antibiotics were used broadly and repeatedly. This study indicated the AR characterization of E, coli in different areas of China. It will be a foundation for studying AR mechanism and regulating the usage of antimicrobial in the poultry industry.展开更多
This paper has been motivated by the following biological question: how influential me desert uerosols in the transmission of meningitidis serogroup A (MenA)? A mathematical model for the dynamical transmission of Men...This paper has been motivated by the following biological question: how influential me desert uerosols in the transmission of meningitidis serogroup A (MenA)? A mathematical model for the dynamical transmission of MenA is considered,with the aim of investigating the impact of desert aerosols.Sensitivity analysis of the model has been performed in order to determine the impact of related parameters on meningitis outbreak.We derive the basic reproduction number R0.We prove that there exists a threshold parameter ζ such that when R0 <ζ< 1,the disease-free equilibrium is globally asymptotically stable (GAS).However,when ζ< R0 < 1,the model exhibits the phenomenon of backward bifurcation.At the endemic level,we show that the number of infectious individuals in the presence of desert aerosols is larger than the correspond-ing number without the presence of desert aerosols.In conjunction with the inequality R0^0< R0 where R0^0 is the basic reproduction number without desert aerosols,we found that the ingestion of aerosols by carriers will increase the endemic level,and the severity of the outbreak.This suggests that the control of MenA passes through a combination of a large coverage vaccination of young susceptible individuals and the production of a vaccine with a high level of efficacy as well as respecting the hygienic rules to avoid the inhalation of desert aerosols.Theoretical results are supported by numerical simulations.展开更多
BACKGROUND Legionella pneumophila(L.pneumophila)is a gram-negative intracellular bacillus composed of sixteen different serogroups.It is mostly known to cause pneumonia in individuals with known risk factors as immuno...BACKGROUND Legionella pneumophila(L.pneumophila)is a gram-negative intracellular bacillus composed of sixteen different serogroups.It is mostly known to cause pneumonia in individuals with known risk factors as immunocompromised status,tobacco use,chronic organ failure or age older than 50 years.Although parapneumonic pleural effusion is frequent in legionellosis,pleural empyema is very uncommon.In this study,we report a case of fatal pleural empyema caused by L.pneumophila serogroup 1 in an 81-year-old man with multiple risk factors.CASE SUMMARY An 81-year-old man presented to the emergency with a 3 wk dyspnea,fever and left chest pain.His previous medical conditions were chronic lymphocytic leukemia,diabetes mellitus,chronic kidney failure,hypertension and hyperlipidemia,without tobacco use.Chest X-ray and comouted tomographyscan confirmed a large left pleural effusion,which puncture showed a citrine exudate with negative standard bacterial cultures.Despite intravenous cefotaxime antibiotherapy,patient’s worsening condition after 10 d led to thoracocentesis and evacuation of 2 liters of pus.The patient progressively developed severe hypoxemia and multiorgan failure occurred.The patient was treated by antibiotherapy with cefepime and amikacin and with adequate symptomatic shock treatment,but died of uncontrolled sepsis.The next day,cultures of the surgical pleural liquid samples yielded L.pneumophila serogroup 1,consistent with the diagnosis of pleural legionellosis.CONCLUSION L.pneumophila should be considered in patients with multiple risk factors and undiagnosed pleural empyema unresponsive to conventional antibiotherapy.展开更多
Cholera continues to be one of the most common causes of morbidity and mortality among children and adults in developing countries. Vaccine against cholera is an approach in the control of this epidemic and pandemic d...Cholera continues to be one of the most common causes of morbidity and mortality among children and adults in developing countries. Vaccine against cholera is an approach in the control of this epidemic and pandemic disease. From the development of very early oral cholera vaccine, advances in vaccine development documented due to a good illustration of the epidemiology, outbreak strategy, and pathophysiology of the disease causing pathogen. The newer-generation oral cholera vaccines are safe and guarantee a high level of protection during outbreak settings for several years. Yet infants and young children in developing countries are hyporesponsive to vaccines and show poor protection against cholera. In this review, we survey and analyse our current knowledge on the etiology of cholera, its clinical manifestation, global epidemiology and elaborate the vaccine candidates, which are effective against the pathogen and the corresponding immune responses to the available vaccines. These reviews comprehensively cover the salient features of recent discoveries related to Vibrio cholerae virulence, past and present vaccine candidates and their advantages and disadvantages with their development strategies. We believe that the advances that have been included in this review will give a comprehensive insight to the prevention and control of cholera outbreaks and development of effective cholera vaccines.展开更多
Neisseria meningitidis is the leading cause of bacterial meningitis and classified into 13serogroups based on the immunological reactivity of the capsular polysaccharide.1 Serogroups A, B, C, W135 and Y are the most c...Neisseria meningitidis is the leading cause of bacterial meningitis and classified into 13serogroups based on the immunological reactivity of the capsular polysaccharide.1 Serogroups A, B, C, W135 and Y are the most common causes of meningitis.2 Among them, serogroup A and C are the major causes of epidemics in Africa and Asia.2 Most of the epidemic outbreaks of meningococcal meningitis are caused by serogroup A Neisseria meningitidis strain from the 1950s to the 1980s in China.3 During the years 2003 and 2005, a new sequence type （ST-4821） of serogroup C was identified in the Anhui and 11 other provinces of China.4展开更多
Neisseria meningitidis （N. meningitidis） is classified into 13 serogroups based on the immunological reactivity of the capsular polysaccharide.Serogourp-s A,B and C are responsible for over 90% of meningococcal dise...Neisseria meningitidis （N. meningitidis） is classified into 13 serogroups based on the immunological reactivity of the capsular polysaccharide.Serogourp-s A,B and C are responsible for over 90% of meningococcal disease.2 In developed countries, endemic disease is generally caused by serogroups B and C.展开更多
基金supported by Research Fund from Ministry of Health and Ministry of Science and Technology of the People’s Republic of China,2013ZX10004221,2012ZX10004215,and 2011CB504900
文摘Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyperinvasive ST-4821 serogroup C clone associated with this outbreak. Methods The cases were described based on the clinical symptoms and laboratory results. Pharyngeal swabs were cultured for N. meningitidis from men in the jail. Meningococcal isolates were identified by serogrouping, pulsed-field gel electrophoresis （PFGE） and multilocus sequence typing （MLST）, respectively. Four hundred and sixteen serogroup C N. meningitidis strains were collected from 27 provinces between 2003 and 2010 for a nationwide survey and analyzed by PFGE and MLST. Results Three persons in a jail system were infected with invasive N. meningitidis serogroup C. All isolates tested had matching PFGE patterns and belonged to the multilocus sequence type （ST） 4821 clonal complex. All 47 N. meningitidis strains were identified from the pharyngeal swabs of 166 peoples in the jail, and 26 of them belonged to ST-4821 serogroup C clone, and 90.14% （375/416） serogroup C strains identified in the nationwide survey belonged to the ST-4821 complex. The ST-4821 serogroup C clone was spread nationwide, distributed in 24 provinces, especially in eastern provinces between 2003 and 2010. Conclusion Endemic transmission and carriage rate of ST-4821 serogroup C clone are high in this jail system. The ST-4821 serogroup C clone is spreading in China and nationwide distributed despite the existence of some effective vaccines.
文摘A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in recent years. The percentage of isolation was 69.1%. There are 67 serogroups each with 1-2 isolates distributed in different regions, and some of these regions had the preponderant serogroups. Antimicrobial-resistance （AR） of E. coli was so severe that the majority were multi-AR. Fifty percent strains were resistant to 10-19 antimicrobial drugs. Overall, the isolates represented resistance to nalidixic acid （88.1%）, tetracycline （85.7%）, sulfamethoxazole （81.0%）, trimethoprim-sulfamethpxazole （77.1%）, ampicillin （76.2%）, amoxilline （74.3%）, streplomycin （66.2%）, fluoroquinolones （57.1-66.7%）, chloramphenicol （52.9%）, gentamicin （39.0%）, and kanamycin （36.2%）. The isolates were sensitive to cefalexin, amoxilline-clavulanic acid, amikacin, and florfenicol with an AR rate of 0-19,5% only, The results showed that the AR was more severe in chicken farms in which the antibiotics were used broadly and repeatedly. This study indicated the AR characterization of E, coli in different areas of China. It will be a foundation for studying AR mechanism and regulating the usage of antimicrobial in the poultry industry.
文摘This paper has been motivated by the following biological question: how influential me desert uerosols in the transmission of meningitidis serogroup A (MenA)? A mathematical model for the dynamical transmission of MenA is considered,with the aim of investigating the impact of desert aerosols.Sensitivity analysis of the model has been performed in order to determine the impact of related parameters on meningitis outbreak.We derive the basic reproduction number R0.We prove that there exists a threshold parameter ζ such that when R0 <ζ< 1,the disease-free equilibrium is globally asymptotically stable (GAS).However,when ζ< R0 < 1,the model exhibits the phenomenon of backward bifurcation.At the endemic level,we show that the number of infectious individuals in the presence of desert aerosols is larger than the correspond-ing number without the presence of desert aerosols.In conjunction with the inequality R0^0< R0 where R0^0 is the basic reproduction number without desert aerosols,we found that the ingestion of aerosols by carriers will increase the endemic level,and the severity of the outbreak.This suggests that the control of MenA passes through a combination of a large coverage vaccination of young susceptible individuals and the production of a vaccine with a high level of efficacy as well as respecting the hygienic rules to avoid the inhalation of desert aerosols.Theoretical results are supported by numerical simulations.
文摘BACKGROUND Legionella pneumophila(L.pneumophila)is a gram-negative intracellular bacillus composed of sixteen different serogroups.It is mostly known to cause pneumonia in individuals with known risk factors as immunocompromised status,tobacco use,chronic organ failure or age older than 50 years.Although parapneumonic pleural effusion is frequent in legionellosis,pleural empyema is very uncommon.In this study,we report a case of fatal pleural empyema caused by L.pneumophila serogroup 1 in an 81-year-old man with multiple risk factors.CASE SUMMARY An 81-year-old man presented to the emergency with a 3 wk dyspnea,fever and left chest pain.His previous medical conditions were chronic lymphocytic leukemia,diabetes mellitus,chronic kidney failure,hypertension and hyperlipidemia,without tobacco use.Chest X-ray and comouted tomographyscan confirmed a large left pleural effusion,which puncture showed a citrine exudate with negative standard bacterial cultures.Despite intravenous cefotaxime antibiotherapy,patient’s worsening condition after 10 d led to thoracocentesis and evacuation of 2 liters of pus.The patient progressively developed severe hypoxemia and multiorgan failure occurred.The patient was treated by antibiotherapy with cefepime and amikacin and with adequate symptomatic shock treatment,but died of uncontrolled sepsis.The next day,cultures of the surgical pleural liquid samples yielded L.pneumophila serogroup 1,consistent with the diagnosis of pleural legionellosis.CONCLUSION L.pneumophila should be considered in patients with multiple risk factors and undiagnosed pleural empyema unresponsive to conventional antibiotherapy.
文摘Cholera continues to be one of the most common causes of morbidity and mortality among children and adults in developing countries. Vaccine against cholera is an approach in the control of this epidemic and pandemic disease. From the development of very early oral cholera vaccine, advances in vaccine development documented due to a good illustration of the epidemiology, outbreak strategy, and pathophysiology of the disease causing pathogen. The newer-generation oral cholera vaccines are safe and guarantee a high level of protection during outbreak settings for several years. Yet infants and young children in developing countries are hyporesponsive to vaccines and show poor protection against cholera. In this review, we survey and analyse our current knowledge on the etiology of cholera, its clinical manifestation, global epidemiology and elaborate the vaccine candidates, which are effective against the pathogen and the corresponding immune responses to the available vaccines. These reviews comprehensively cover the salient features of recent discoveries related to Vibrio cholerae virulence, past and present vaccine candidates and their advantages and disadvantages with their development strategies. We believe that the advances that have been included in this review will give a comprehensive insight to the prevention and control of cholera outbreaks and development of effective cholera vaccines.
文摘Neisseria meningitidis is the leading cause of bacterial meningitis and classified into 13serogroups based on the immunological reactivity of the capsular polysaccharide.1 Serogroups A, B, C, W135 and Y are the most common causes of meningitis.2 Among them, serogroup A and C are the major causes of epidemics in Africa and Asia.2 Most of the epidemic outbreaks of meningococcal meningitis are caused by serogroup A Neisseria meningitidis strain from the 1950s to the 1980s in China.3 During the years 2003 and 2005, a new sequence type （ST-4821） of serogroup C was identified in the Anhui and 11 other provinces of China.4
文摘Neisseria meningitidis （N. meningitidis） is classified into 13 serogroups based on the immunological reactivity of the capsular polysaccharide.Serogourp-s A,B and C are responsible for over 90% of meningococcal disease.2 In developed countries, endemic disease is generally caused by serogroups B and C.
