To identify the pathogenic bacteria causing calf diarrhea in farms in northern Hebei Province,247 samples of anal swabs,feces,liver and other diseased tissues of dairy meat calves suffering from diarrhea in farms in above area were collected from 2021 to 2023.The bacterial isolation and culture,morphological observation,biochemical test and PCR methods were used to isolate and identify Proteus mirabilis(PM),and the pathogenicity was detected in mice using artificial infection test(0.20mL/mouse,with a bacterial content of 108cfu/mL),and the virulence genes,drug resistance,and related drug resistance genes were examined using PCR method and K-B drug sensitive paper method.The Fisher exact probability method in SPSS 18 software was used to analyze the correlation between PM resistance phenotype and related drug resistance genes.The results showed that 102 PM strains were isolated and identified from 247 samples of dairy/meat calves with diarrhea,and of which 72 isolates that caused the disease and death in mice were pathogenic PM,and the mortality rate of mice ranged from 40%to 100%.The detection rates of virulence genes fliL,zapA,pmfA,atfA,rsbA,ureC and atfC in 72 pathogenic PM isolates ranged from 63.4%to 100%,while they were 2.7%-8.1%for other virulence genes.More than 51.4%of the 72 PM isolates were resistant to 12 drugs such as amoxicillin,ampicillin,and apramycin,and 6.9%-33.3%of the isolates were resistant to other drugs,presenting multiple drug resistance(MDR)and resistance to at least 3 types of drugs.The detection rates of β-lactam resistance genes blaOXA,blaCTX-M,and blaTEM,sulfonamide resistance genes Sul1,Sul2,and Sul3,aminoglycoside resistance genes adA and aac(6')-Ib,tetracycline resistance genes TetA and TetM in the 72 PM isolates ranged from 43.2%to 98.6%,and they were 4.2%-33.3%for other resistance genes,and the drug resistance phenotype was basically positively correlated with the drug resistance genotype(except for polymyxin and macrolide).This study provides a reference basis for the prevention and control of diarrhea caused by Proteus disease in dairy and meat calves.
NETL
NSTL
维普
万方数据
