Contact with food animals was associated with SARS-CoV infection in the People’s Republic of China.

, 1a, 2a, 2b, 3a, 4a, 5b, X, and Y, found that all belong to a new sequence type (ST), ST91. Pulsed-field gel electrophoresis revealed 154 pulse types with 655 S. flexneri isolates analyzed and identified 57 serotype switching events. The data suggest that S. flexneri epidemics in China have been caused by a single epidemic clone, ST91, with frequent serotype switching to evade infection-induced immunity to serotypes to which the population was exposed previously. The clone has also acquired resistance to multiple antibiotics. These findings underscore the challenges to the current vaccine development and control strategies for shigellosis.

Streptococcus suis sequence type (ST) 7 has been spreading throughout China. To determine events associated with its emergence, we tested 114 isolates. In all 106 ST7 strains responsible for human outbreaks and sporadic infections, the tetracycline-resistance gene, tetM, was detected on the conjugative transposon Tn 916. Horizontal transmission of tetM is suspected.

Shigella flexneri is the major Shigella species that causes diarrheal disease in developing countries. It is further subdivided into 15 serotypes based on O-antigen structure. Serotyping of S. flexneri is important for epidemiological purposes. In this study, we developed a multiplex PCR assay targeting the O-antigen synthesis gene wzx and the O-antigen modification genes gtrI, gtrIC, gtrII, oac, gtrIV, gtrV, and gtrX for molecular serotyping of S. flexneri. The multiplex PCR assay contained eight sets of specific PCRs in a single tube and can identify 14 of the 15 serotypes (the exception being serotype Xv) of S. flexneri recognized thus far. A nearly perfect concordance (97.8%) between multiplex PCR assay and slide agglutination was observed when 358 S. flexneri strains of various serotypes were analyzed, except that 8 strains were carrying additional cryptic and/or defective serotype-specific genes. The multiplex PCR assay provides a rapid and specific method for the serotype identification of S. flexneri.