Isolation,Identification And Drug Resistance Analysis Of Staphylococci Derived From Canine Skin

Staphylococcus is a conditional pathogen widely present in humans,animals and the environment.This bacterium is one of the main pathogens causing canine pustulosis.Canine pustulosis can occur in dogs of all ages and is characterized by frequent susceptibility,long course of disease,easy recurrence,complex etiology and difficult prevention and treatment.Various antimicrobial drugs remain the main choice for the treatment of associated bacterial infectious diseases in pet clinics,with some quinolones,β-lactam antibiotics,chloramphenicol,lincosamides,and tetracyclines as the drugs of choice in pet clinics.The frequent and long-term use of antibiotics in pet clinics has led to the emergence of clinical isolates of staphylococci resistant to various antibiotics,reducing the effectiveness of various drugs in treating related diseases.Staphylococcus,as a conditionally pathogenic bacteria that can be transmitted between humans and animals,has been reported at home and abroad to isolate homologous Staphylococcus between humans and pets,and the study of the resistance of Staphylococcus of canine origin to various antibiotics and the related resistance genes it carries is important for guiding the clinical use of drugs in pets and maintaining the health of pet owners.Therefore,this study aims to investigate the drug resistance of Staphylococcus spp.of canine origin.A total of 295 samples of skin infections from dogs of various breeds and age stages were selected for this experiment.After the initial isolation and purification of bacteria,the species of Staphylococcus were further identified by a combination of Gram stain microscopy,biochemical identification,and 16S rDNA identification.The Kirby-Bauer paper diffusion method,micro-broth dilution method and PCR technique were used to study the resistance of the isolated staphylococci to nine antibiotics and the carriage of the mecA resistance gene of the multi-drug resistant strain of benzocillin sodium.The following results were obtained.1.The results of bacterial isolation and identification tests showed that a total of 268 strains of various types of staphylococci were isolated from 295 samples of canine skin infections,including 161 strains of Staphylococcus pseudo-intermediate;43 strains of Staphylococcus aureus;21 strains of Staphylococcus epidermidis;11 strains of Staphylococcus squirrel;10 strains of Staphylococcus schlegelii;and a total of 22 strains of other species.The identification results showed that the main pathogenic bacteria of bacterial skin disease in dogs in the area was Staphylococcus pseudintermedius.2.The results of the drug resistance phenotype of the isolated strains showed that there were 62 single resistant strains;61 dual resistant strains;51 triple resistant strains;28quadruple resistant strains;and 19 quintuple resistant strains.Vancomycin sensitivity is the best among the commonly used antibiotics in pet clinic,and no strains resistant to vancomycin were found,followed by florfenicol,cefotaxime,cefadroxil,benzathine sodium,while enrofloxacin,amoxicillin clavulanic acid potassium,doxycycline and lincomycin resistance is serious,and the strains resistant to multiple antimicrobials accounted for about37%.3.The results of resistance testing showed that the MIC of lincomycin was 128 ug/m L for almost all multi-drug resistant strains,and most multi-drug resistant strains showed high resistance to lincomycin;30 strains showed high resistance to enrofloxacin,and their MIC values were all 32 ug/m L and above;24 strains showed high resistance to amoxicillin clavulanate potassium,and their The MIC values of all the strains exceeded 32ug/m L;18strains showed high resistance to cefadroxil,with MIC values of 64 ug/m L and above;2strains showed high resistance to florfenicol,with MIC values of 128 ug/m L;6 strains showed high resistance to benzocillin sodium,with MIC values of 64 ug/m L and above;2 strains showed high resistance to cefotaxime,with MIC values of 64 ug/m L and above.Two strains showed high resistance to cefotaxime,and their MIC values were 128 ug/m L.4.The results of resistance gene detection showed that 45 isolates showing resistance to benzocillin sodium were detected with mecA resistance gene.5、The results of biofilm forming ability assay showed that 25 strains had the ability to form biofilm,and 7 of them were strong biofilm forming ability.Conclusion: A total of 268 strains of various staphylococci were isolated from 295 samples of canine skin infections,and 221 drug-resistant strains were screened by Kirby-Bauer paper diffusion method and micro broth dilution method,and the drug resistance rate was 82.46%,among which 98 strains were multi-drug resistant strains,which showed that the current situation of drug resistance of staphylococci of canine skin origin in this area was relatively serious.