Presence of bacteroidales as a predicator of human enteric viruses in Haihe River of Tianjin City, China
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
Authors: Zhou, Shuqing; Yang, Dong; Xu, Qunying; Yang, Zhongwei; Jin, Min; Yin, Jing; Wang, Huaran; Zhou, Kun; Wang, Lianqi; Li, Junwen; Shen, Zhiqiang
Abstract
Traditional microbe indicators including total bacteria, total coliforms, fecal coliforms, Escherichia coli, enterococci, and F+ coliphage are all frequently used to characterize the microbial contamination state of water bodies for their correlation with pathogenic bacteria. However, these indicators have a poor relationship with viruses, which pose serious threat to economic and human health. Alternative indicators such as bacteroidales may be suitable complementary alternatives to traditional microbe indicators and are being increasingly reported. In the present study, water was analyzed for selected sites along Haihe River in Tianjin for traditional indicators, an alternative indicator (bacteroidales), pathogenic bacteria (Salmonella, Escherichia coli (E. coli) O157:H7, and Vibrio parahaemolyticus), viruses (enteric adenovirus, norovirus, enterovirus, poliovirus and rotavirus), and physicochemical parameters. Results indicated that traditional microbe indicators detected in this study showed good correlation with pathogenic bacteria, and the alternative indicator (bacteroidales) had a surprisingly good relationship with viral presence. We propose that bacteroidales might be a suitable complementary indicator for viral contamination in water bodies.
Structural and phenotypic analysis of Chikungunya virus RNA replication elements
NUCLEIC ACIDS RESEARCH
Authors: Kendall, Catherine; Khalid, Henna; Mueller, Marietta; Banda, Dominic H.; Kohl, Alain; Merits, Andres; Stonehouse, Nicola J.; Tuplin, Andrew
Abstract
Chikungunya virus (CHIKV) is a re-emerging, pathogenic Alphavirus transmitted to humans by Aedes spp. mosquitoes. We have mapped the RNA structure of the 5' region of the CHIKV genome using selective 2'-hydroxyl acylation analysed by primer extension (SHAPE) to investigate intramolecular base-pairing at single-nucleotide resolution. Taking a structure-led reverse genetic approach, in both infectious virus and sub-genomic replicon systems, we identified six RNA replication elements essential to efficient CHIKV genome replication - including novel elements, either not previously analysed in other alphaviruses or specific to CHIKV. Importantly, through a reverse genetic approach we demonstrate that the replication elements function within the positive-strand genomic copy of the virus genome, in predominantly structure-dependent mechanisms during efficient replication of the CHIKV genome. Comparative analysis in human and mosquito-derived cell lines reveal that a novel element within the 5'UTR is essential for efficient replication in both host systems, while those in the adjacent nsP1 encoding region are specific to either vertebrate or invertebrate host cells. In addition to furthering our knowledge of fundamental aspects of the molecular virology of this important human pathogen, we foresee that results from this study will be important for rational design of a genetically stable attenuated vaccine.