Isolation,identification,and biological characterization of enterotoxigenic Escherichia coli from a South China tiger
10.3969/j.issn.1002-2694.2025.00.096
- VernacularTitle:华南虎源产肠毒素型大肠杆菌的分离鉴定及其生物学特性研究
- Author:
Jing-ru XU
1
;
Zhi-hao ZHU
;
Yu-qi LI
;
Si-si FAN
;
Ya-li KANG
;
Yu-bin ZHUO
;
Ling-shan HUANG
;
Shu-qi QIU
;
XUE-YUXI
;
Xiao-ping WU
;
Yu-ting LIAO
;
Wei-ye LIN
;
Xiao-ziyi XIAO
;
Xue-jin LI
;
Teng-teng CHEN
;
Xi-pan LIN
;
Kai-xiong LIN
;
Ke-wei FAN
Author Information
1. 龙岩学院生命科学学院,福建省家畜传染病防治与生物技术重点实验室,动物源性人兽共患病防控福建省高校工程研究中心,龙岩 364000;福建农林大学动物科学学院,福州 350002
- Publication Type:Journal Article
- Keywords:
South China tiger;
enterotoxigenic Escherichia coli;
isolation and identification;
pathogenicity
- From:
Chinese Journal of Zoonoses
2025;41(6):567-573
- CountryChina
- Language:Chinese
-
Abstract:
This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.
