RESUMO
Objective To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows.Methods The milk sample was collected from a cow with mastitis,which was pretreated with 4％ NaOH and inoculated with L-J medium for Mycobacterium isolation.The positive cultures were initially identified by acid-fast staining and multi-loci PCR,then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA,hsp65,ITS and SodA genes.The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay.Results Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis,which were identified as non-tuberculosis mycobacterium by multi-loci PCR,and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis.The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics,including rifampicin and isoniazid,but they were sensitive to amikacin,moxifloxacin,levofloxacin,ethambutol,streptomycin,tobramycin,ciprofloxacin and linezolid.Conclusions Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique.The results of the study can be used as reference for the prevention and control the infection in cows.
RESUMO
Objective To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows.Methods The milk sample was collected from a cow with mastitis,which was pretreated with 4％ NaOH and inoculated with L-J medium for Mycobacterium isolation.The positive cultures were initially identified by acid-fast staining and multi-loci PCR,then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA,hsp65,ITS and SodA genes.The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay.Results Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis,which were identified as non-tuberculosis mycobacterium by multi-loci PCR,and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis.The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics,including rifampicin and isoniazid,but they were sensitive to amikacin,moxifloxacin,levofloxacin,ethambutol,streptomycin,tobramycin,ciprofloxacin and linezolid.Conclusions Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique.The results of the study can be used as reference for the prevention and control the infection in cows.
RESUMO
Mycobacterium thermoresistibile is a non-tuberculous mycobacterium strongly associated with human infections. Since 1966, there have only been six reports of its isolation from clinical samples. We report on the first case from Europe and review all the previous cases. Identification was achieved with sequencing of the 16S rRNA and hsp65 genes. This study presents its phenotypic and biochemical profile, susceptibilities to selected antibiotics and hsp65 polymerase chain reaction-restriction fragment length polymorphism profile with BsteII and Hae III .