Isolation,Identification and Mouse Infection Tests of Klebsiella pneumoniae and Escherichia coli from Rabbits
To investigate the pathogens of respiratory tract infection and diarrhea leading to mortality in rabbits in a large-scale rabbit farm in Liaocheng,Shandong province.Viral and bacterial pathogens were a-septically isolated and cultured from the trachea,lungs and liver.The strains were subjected to bacterial iso-lation and culture,Gram staining,biochemical identification,homology comparison analysis of the 16S rRNA sequence and construction of a phylogenetic tree in order to determine their species.The drug resist-ance and pathogenicity of the isolates were evaluated by conducting drug sensitivity testing,detecting of drug resistance genes and performing animal regression analysis.The results demonstrated that all of the viruses tested were negative and the isolation of two strains,Klebsiella pneumoniae KF1 and KQ2,from the lungs and trachea of a single rabbit.Additionally,a strain of Escherichia coli was obtained from its liv-er,designated as EG3.The drug susceptibility test results revealed that strains KF1,KQ2 and EG3 exhibi-ted resistance to colistin and ampicillin sodium,while demonstrating sensitive to amikacin and flufenicol.The presence of drug resistance genes mcr-1 and blaTEM was observed in all three strains.Animal pathoge-nicity tests showed that in the KF1 group,50％of the SPF mice succumbed within 5 hours,exhibiting com-plete mortality at 24 hours;whereas all mice in the mixed group experienced total mortality after 12 hours.The mortality rate was 100％within 48 hours for all groups exposed to KQ2 and EG3 while the control group exhibited normal survival without any observed abnormalities.The above study indicated that the mixed infection of Escherichia coli and Klebsiella pneumoniae was the main reason of mortality of young rabbits,and the three isolates can cause death of mice by single and mixed infections.
RabbitKlebsiella pneumoniaeEscherichia coliIsolation and identificationDrug resistance gene
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维普
