摘要
Abstract
In order to isolate and identify the pathogenic bacteria that cause diarrhea in Xizang sheep in the herdsmen households in Karuo District,Changdu City,and study their antibiotic resistance,providing data support for the prevention and control of diarrhea in Xizang sheep in affected areas,this study collected fecal samples from Xizang sheep suffering from diarrhea,isolated and cultured pathogenic bacteria,and per-formed staining microscopy,biochemical identification,and molecular biology identification to conduct in vitro drug sensitivity tests on the iso-lated bacteria.As a result,three strains of bacteria were isolated from seven samples of diarrhea feces from Xizang sheep,which were Gram positive cocci detected by staining microscopy.They were named changdu-1,changdu-2 and changdu-3.Three strains of bacteria exhibit the same biochemical characteristics,all capable of decomposing trehalose,maltose,fructose,trisaccharide,sucrose,lactose,glucose,sorbitol,and mannitol,but unable to decompose arabinose,raffinose,xylose,and xylose.The genomic DNA of the isolated bacteria was extracted and ampli-fied by 16S rRNA PCR to obtain a product with a length of approximately 1 500 bp,which was consistent with the expected results.The ho-mology analysis of the 16S rRNA sequences of the isolates showed that the homology between the three isolates was 100.0%,and the homolo-gy with the reference strain of Enterococcus faecalis was as high as 99.6 to 100.0%.Evolutionary tree analysis shows that the isolated strain was on the same branch as the reference strain of Enterococcus faecalis,but on different branches from Escherichia coli,Bacillus lichenifor-mis,Bacillus cereus,and Clostridium perfringens.The in vitro drug sensitivity results of the three isolated strains were similar,showing sensi-tivity to ofloxacin,enrofloxacin,etc.,but resistance to compound sulfamethoxazole,tetracycline,gentamicin,and lincomycin.The research re-sults provided scientific guidance for the treatment of diarrheal sheep in herdsmen households.关键词
藏羊/粪肠球菌/分离鉴定/耐药性Key words
Xizang sheep/enterococcus faecalis/isolation and identification/drug resistance分类
农业科技
