Isolation,identification and biological characteristics of five strains of Citrobacter fredii from South China tiger
In order to understand the carrying status of potential pathogens of South China tiger in Meihuashan Breeding Institute of Fujian Province and analyze relevant biological characteristics,this study isolated bacteria from 104 tissues,feces,anus swab and nose swab of South China tiger collected from Meihuashan Breeding Institute of Fujian Province from 2018 to 2021.Biochemical identification,16S rRNA sequence amplification,virulence gene detection,pathogenicity test and drug susceptibility test were performed.The results showed that 5 strains of Citrobacter freundii were isolated from 104 South China tiger samples through isolation and culture,morphological observation,biochemical test and 16S rRNA sequence analysis.The sequence similarity of 16S rRNA among the five isolates was 99.3％-99.7％,and the similarity with the 18 strains of Citrobacter freundii from different sources was 98.3％-99.9％.Genetic analysis showed that the 5 isolates were closely related to the 18 strains of Citrobacter freundii in the same evolutionary branch.Virulence gene test results showed that FJ/Tiger-1803,FJ/Tiger-1804,FJ/Tiger-1806 and FJ/Tiger-1807 all carried genes ureD,ureE and ureABC;FJ/Tiger-1805 only carried genes ureD and ureE.The results of pathogenicity test in mice showed that healthy mice were infected by intrabitoneal injection at the same concentration(1 × 109 CFU/mL).The mortality rates of FJ/Tiger-1803,FJ/Tiger-1806,FJ/Tiger-1804,FJ/Tiger-1807 and FJ/Tiger-1805 in mice were 100％,100％,80％,80％and 0,respectively.The results of drug sensitivity test showed that the isolates had different resistance to 14 kinds of antibiotics,among which amoxicillin,penicillin G,vancomycin and erythromycin were the most resistant,and showed multiple resistance.In conclusion,five strains of Cit-robacter freundii with strong pathogenicity and severe drug resistance to mice were isolated from dif-ferent samples of South China tiger in this study,which should be paid attention to clinically.
Panthera tigris amoyensisCitrobacter freundiiisolation and identificationviru-lence genedrug resistance
国家科技期刊平台
NSTL
万方数据
维普
