Pathogens isolated from bovine clinical mastitis and their antimicrobial resistance


ARDIÇLI Ö. , KAHYA DEMİRBİLEK S. , CARLI K. T.

MEDYCYNA WETERYNARYJNA-VETERINARY MEDICINE-SCIENCE AND PRACTICE, vol.78, no.1, pp.19-24, 2022 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 78 Issue: 1
  • Publication Date: 2022
  • Doi Number: 10.21521/mw.6606
  • Title of Journal : MEDYCYNA WETERYNARYJNA-VETERINARY MEDICINE-SCIENCE AND PRACTICE
  • Page Numbers: pp.19-24
  • Keywords: mastitis, antimicrobial resistance, dairy cattle, bacterial strains, SUBCLINICAL MASTITIS, DAIRY-COWS, STAPHYLOCOCCUS-AUREUS, STREPTOCOCCUS-DYSGALACTIAE, ETIOLOGIC AGENTS, UDDER PATHOGENS, SUSCEPTIBILITY, PREVALENCE, HERDS, LACTATION

Abstract

This study aimed to isolate aerobic and microaerophilic bacteria from mastitis milk samples, as well as to determine their antibiotic resistance. A total of 196 bovine mastitis milk samples were tested by standard bacteriological methods and with API identification test kits. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method. The results revealed that the predominant isolate was S. aureus, with an isolation rate of 28%, followed by Streptococcus spp. (27%) and E. coli (19%). Isolation rates for Corynebacterium spp., Mycoplasma spp., and Pseudomonas aeruginosa were 11%, 6%, and 4%, respectively. Compared to the bacteria mentioned above, lower percentages were observed for Trueperella pyogenes (2%), Pasteurella multocida (2%), and Klebsiella pneumoniae (1%). A broad evaluation of antimicrobial resistance showed that the pathogens were resistant to tetracycline (68.63%), oxytetracycline (41.57%), ampicillin (39.08%), ceftiofur (38.1%), cephalexin (32.26%), penicillin (31.25%), amoxicillin/clavulanic acid (24.53%), enrofloxacin (24.44%), gentamycin (23.68%), and trimethoprim/sulfamethoxazole (22.09%). This study demonstrated that the sources of bacteria isolated from mastitis bovine milk samples were both contagious and environmental. More importantly, the present results demonstrate a critically high antimicrobial resistance in dairy cattle. For instance, E. coli isolates showed a crucial resistance to commonly used and recommended antimicrobials, including ceftiofur (100%), cephalexin (83.33%), and tetracycline (94.44%). The results of this study may provide valuable information about clinical aspects of bovine mastitis infections and current antimicrobial resistance levels in dairy cattle.