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Genotype and virulence gene analyses of Bacillus cereus group clinical isolates from the Chinese softshell turtle ( Pelodiscus sinensis ) in Taiwan
Author(s) -
Cheng LiWu,
Rao Shreesha,
Poudyal Sayuj,
Wang PeiChi,
Chen ShihChu
Publication year - 2021
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/jfd.13473
Subject(s) - biology , microbiology and biotechnology , virulence , bacillus cereus , genotype , cereus , phylogenetic tree , gene , enterotoxin , polymerase chain reaction , intergenic region , bacillus thuringiensis , bacteria , genetics , genome , escherichia coli
Chinese softshell turtles ( Pelodiscus sinensis ) (CST) are susceptible to infections by bacteria belonging to the Bacillus cereus group (Bcg). Bcg includes several closely related species, two of which, B . cereus and B . thuringiensis , are pathogens of aquatic animals or insects. In the present study, we collected 57 Bcg isolates from diseased CST from 2016 to 2019 in Kaohsiung and Pingtung, where most CST farms are located in Taiwan. All isolates were divided into four genotypes with two restriction enzymes, Sma I and Not I, by pulsed‐field gel electrophoresis and enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC‐PCR). Representative isolates from each genotype were subjected to phylogenetic tree analysis using 16S rDNA and pyruvate carboxylase genes as phylogenetic markers, and these CST isolates appeared in different clades. PCR was performed targeting six selected virulence genes, four of which were detected in CST isolates, including cytotoxin K (1/57), hblC of the haemolysin BL complex (46/57), nheA of the non‐haemolytic enterotoxin complex (52/57) and enterotoxin FM (57/57), whereas cereulide synthetase and cereulide peptide synthase‐like genes were not detected in any isolates.