By using multilocus sequence analysis, five Borrelia valaisiana-related strains isolated from rodents and ticks in southwestern China were eventually classified as a new genospecies of B. burgdorferi sensu lato rather than B. valaisiana. The finding explained the differences in transmission cycle and phenotype between B. valaisiana strains from Europe and B. valaisiana-related strains from eastern Asia.Strains of Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis, have been divided into at least 13 genospecies (7,8,10,15). The bacterium is maintained mainly in natural foci through the transmission cycles of Ixodes ticks and a wide variety of vertebrate hosts (15). Different B. burgdorferi sensu lato genospecies are distributed unevenly throughout the world and are associated with distinct ecologic features (15).To date, five established genospecies and a group of B. valaisiana-related strains have been isolated in mainland China (7,14,16). B. garinii and B. afzelii are major genospecies in natural foci of northern China and are maintained mainly in a tick-rodent cycle (16). Some B. valaisiana-related strains and B. sinica strains were recently isolated in some regions of the Yangtze River valley (7,14). B. valaisiana-related strains were once tentatively classified as B. afzelii based on the phylogenetic analysis of the rrs gene (2) and then considered to be B. valaisiana based on the phylogenetic analysis of the rrf-rrl intergenic spacer, the rrs gene, and the flagellin gene (4). Recently, Masuzawa et al. suggested that these isolates should be classified as a new genospecies based on a similar phylogenetic analysis (5). In order to clarify the exact taxonomy of B. valaisiana-related strains and explain the differences in transmission cycle and phenotype between B. valaisiana-related strains and B. valaisiana strains, we examined five B. valaisiana-related strains isolated from Guizhou Province in southwestern China by multilocus sequence analysis (MLSA), which was confirmed to surpass the discrimination power of whole-genome DNA-DNA hybridization (the "gold standard" in taxonomy) for B. burgdorferi sensu lato genospecies definition (8, 10). Moreover, new species B. spielmanii and B. californiensis were also confirmed and validated by MLSA (8, 10).Borrelia strains and culture conditions. The five strains used in this study were isolated either from ticks or from the urinary bladders of rodents in Guizhou Province in southwestern China in May 2006, as described previously (1). Strain QTMP2 was from Ixodes granulatus fed from Niviventer fulvescens, strains QSYSP3 and QSYSP4 were from Haemaphysalis longicornis fed from Apodemus agrarius, strain QSDS4 was from A. agrarius, and strain QLZSP1 was from I. granulatus fed from A. agrarius. These strains belong to the B. valaisiana-related group rather than the B. sinica and other B. burgdorferi sensu lato genospecies according to the results of restriction fragment length polymorphism analysis and the analysis of rrf-rrl intergenic spacer sequences...

Nonsyndromic cleft lip with or without cleft palate (nsCL/P) is one of the most common congenital anomalies in humans. The pathogenesis of nsCL/P involves both genetic and environmental factors. On the basis of linkage data suggesting that 14q21-24 is one of the chromosomal regions that affects nsCL/P and data locating the BMP4 gene to 14q22-23, we performed a case-control study to evaluate whether BMP4 538T/C polymorphism, resulting in an amino acid change of Val/Ala (V152A) in the polypeptide, is associated with nsCL/P in a Chinese children population. Genotypes of 184 patients with nsCL/P and 205 controls were detected using a PCR-RFLP strategy. The results showed significant differences in the genotype and allele distribution of 538T/C polymorphisms of the BMP4 gene among the cases and controls. The 538C allele carriers were associated with a significantly increased risk of nsCL/P as compared with the noncarriers (odds ratio = 1.52; 95% confidence interval, 1.13-2.03; p = 0.005). Hence, our results support the hypothesis that this polymorphism contributes to risk of nsCL/P, which suggests that BMP4 538T/C polymorphisms could be used as genetic susceptibility markers of nsCL/P.

This outbreak of Aeromonas hydrophila was most probably caused by salad ingredients washed in contaminated tank water. We recommended enhancing training of foodhandlers, ensuring tanks and sewerage systems comply with appropriate standards and adequate monitoring of drinking-water sources.

Many viruses can cause respiratory diseases in humans. Although great advances have been achieved in methods of diagnosis, it remains challenging to identify pathogens in unexplained pneumonia (UP) cases. In this study, we applied next-generation sequencing (NGS) technology and a metagenomic approach to detect and characterize respiratory viruses in UP cases from Guizhou Province, China. A total of 33 oropharyngeal swabs were obtained from hospitalized UP patients and subjected to NGS. An unbiased metagenomic analysis pipeline identified 13 virus species in 16 samples. Human rhinovirus C was the virus most frequently detected and was identified in seven samples. Human measles virus, adenovirus B 55 and coxsackievirus A10 were also identified. Metagenomic sequencing also provided virus genomic sequences, which enabled genotype characterization and phylogenetic analysis. For cases of multiple infection, metagenomic sequencing afforded information regarding the quantity of each virus in the sample, which could be used to evaluate each viruses' role in the disease. Our study highlights the potential of metagenomic sequencing for pathogen identification in UP cases. unexplained pneumonia, metagenomics, next-generation sequencing Citation:Zou, X., Tang, G., Zhao, X., Huang, Y., Chen, T., Lei, M., Chen, W., Yang, L., Zhu, W., Zhuang, L., Yang, J., Feng, Z., Wang, D., Wang, D., and Shu, Y. (2017). Simultaneous virus identification and characterization of severe unexplained pneumonia cases using a metagenomics sequencing technique. Sci China Life Sci 60, 279-286.

In this study, 68 group A streptococcus (GAS) isolates associated with two outbreaks of acute glomerulonephritis (AGN) in China were analyzed by emm typing. A total of 11 different emm types were identified. Analysis of emm type distribution suggested that AGN outbreaks in two counties were caused by emm60.1-and emm63.0-type GAS. These two types were further characterized by pulsed-field gel electrophoresis, multilocus sequence typing, sof sequence typing, and PCR-based identification of streptococcal pyrogenic exotoxin A, B, and C (speA, speB, and speC) genes. In antimicrobial susceptibility tests, all outbreak strains were resistant to erythromycin and tetracycline, and the rates of resistance of nonoutbreak strains to the two antibiotics were 63.6% and 90.9%. This study is also the first to report a nephritogenic M63 GAS strain.