Capsule switching of Neisseria meningitidis sequence type 7 serogroup A to serogroup X.

Objectives: The bacterial pathogen Neisseria meningitidis is able to escape the currently available capsule-based vaccines by undergoing capsule switching. In this study, we investigated whether capsule switching has occurred in a recently emerged sequence type (ST) 7 serogroup X isolate in China, for which currently no vaccine is available.

Methods: To identify capsule switching breakpoints, the capsule locus and flanking regions of the ST-7 serogroup X isolate and three endemic ST-7 serogroup A isolates were sequenced and compared.

Enterovirus 71 infection causes severe pulmonary lesions in gerbils, meriones unguiculatus, which can be prevented by passive immunization with specific antisera.

Neurogenic pulmonary edema caused by severe brainstem encephalitis is the leading cause of death in young children infected by Enterovirus 71 (EV71). However, no pulmonary lesions have been found in EV71-infected transgenic or non-transgenic mouse models. Development of a suitable animal model is important for studying EV71 pathogenesis and assessing effect of therapeutic approaches.

Foodborne pathogens in retail oysters in south China.

Objective: To investigate the occurrence of important foodborne pathogens in shellstock Pacific oysters in the food markets in South China.

Methods: From July 2007 to June 2008, retail oysters were collected in different seasons from South China and analyzed for the prevalence and levels of Listeria monocytogenes, Vibrio vulnificus and Vibrio parahaemolyticus.

Results: None of L.

[Establishment and application of loop-mediated isothermal amplification method for rapid detection].

Objective: To develop a loop-mediated isothermal amplification (LAMP) method for rapid diagnosing of Legionella pneumophila in the Pathogen Detection Department(PDD) or in small-scale laboratory.

Methods: Five primers (2 Inner Primers, 2 Outer Primers and a Loop Primer) for the LAMP test were designed by targeting the mip gene of L. pneumophila and reaction system of LAMP reaction was optimized.

[Study on the difference of genes and the type identification of hantavirus from Lishui, Zhejiang province].

Objective: To isolate hantavirus from Lishui county--one of the epidemic regions for hemorrhagic fever with renal syndrome (HFRS), in Zhejiang province, and to identify the serotype and molecular/biological characteristics of a new HTN subtype hantavirus (HV) strains, hopefully to provide evidence for HFRS prevention and therapy.

Methods: Data on the host animals was collected from Lishui, Zhejiang province in 2007. Direct immunofluorscece assay was adopted to determine HFRS antigens and the lung tissues from HV infected Vero-E6 cells for HV isolation, then total RNA was extracted from Hantavirus Lishui strains and amplified by RT-PCR M, S segments of strains genome were also cloned and sequenced and compared with those of other strains of HV.

[Molecular characterization and sequence comparison of the M and S segments of Hantavirus ZJ5 strain].

Objective: In order to understand the molecular characters of Hantavirus ZJ5 strain, its complete M and S genome were sequenced and compared with that of other hantavirus strains.

Methods: We prepared the total RNA from ZJ5. Infected cells and the raw or purified RT-PCR product was cloned and sequenced.

The rate-limiting step in anaerobic digestion in the presence of phosphine.

Methanogenesis is the most important anaerobic biodegradation process in nature, which is accomplished by three different kinds of bacteria - hydrolytic, acetogenic and methanogenic bacteria (MB). An experiment was performed to determine the rate-limiting step of methanogenesis under the influence of various phosphine concentrations (100, 300, 500, 700 and 1000 ppm). It was found that the growth of fermentative bacteria (FB) was severely affected by higher concentrations of phosphine (700 and 971 ppm), while the growth of hydrogen-producing acetogenic bacteria (HPAB) and MB was not affected severely at higher phosphine concentrations.

Molecular biological analysis of genotyping and phylogeny of severe acute respiratory syndrome associated coronavirus.

Background: SARS-CoV is the causative agent of severe acute respiratory syndrome (SARS) which has been associated with outbreaks of SARS in Guangdong, Hong Kong and Beijing of China, and other regions worldwide. SARS-CoV from human has shown some variations but its origin is still unknown. The genotyping and phylogeny of SARS-CoV were analyzed and reported in this paper.