Abstract

IDENTIFICATION AND ANTIMICROBIAL RESISTANCE PROFILE OF BACTERIA ISOLATED FROM SUBCLINICAL MASTITIS IN LACTATING DAIRY COWS IN UMDURMAN LOCALITY, SUDAN

Omnia Hassan Ali*, Hisham Ismail Seri, Mohamed A/Elsalam Abdalla, Yassir A. Almofti, Osama Mohamed Mohamed Khair Ali and Siham Elias Suliman

ABSTRACT

Mastitis and subclinical mastitis are major constrain of dairy cattle health and production. This study aimed to isolate bacteria associated with subclinical mastitis and report their antimicrobial resistance profile. A total of 50 subclinical mastitis samples were collected using California Mastitis Test. Conventional bacteriological and molecular methods were used for identification of the isolates and the antibiotic sensitivity test was performed. Some identified isolates were further sequenced and molecular evolution was studied. 26 isolates (52%) were identified as Staphylococcus aureus, 10 isolates (20%) as E. coli, 8 isolates (16%) as Streptococcus and 6 isolates (12%) as Klebsiella. The phylogentic analysis showed that E. coli was closely related to the strains from China, USA, Sweden, Switzerland and United Kingdom and Klebsiella was closely related to the strain of USA (CP036450). Staphylococcus isolates were found not closely related to the compared strains. Concerning the antibiogram profile, Staphylococcus demonstrated high resistance to Ampicillin, Cephems group, Chloramphenicol, Clindamycin, Erythromycin and Vancomycin and sensitivity to Co-Trimoxazole, Tetracycline, Amikacin and Gentamicin. Streptococcus demonstrated resistance to Ampicillin; Cephems group Amikacin and Co-Trimoxazole. However they showed moderate resistance to Tetracycline and susceptibility to Vancomycin, Chloramphenicol, Clindamycin, Gentamicin and Erythromycin. E. coli and Klebsiella; both showed resistance to Amikacin, Ampicillin, Cefuroxime, Cefotaxime and Co-Trimoxazole. E. coli showed resistance to Ceftriaxone while Klebsiella showed intermediate resistance. Also both showed intermediate resistance to Tetracycline and Vancomycin and susceptibility to Erythromycin, Gentamicin, Chloramphenicol and Clindamycin. In general, the isolates demonstrated high susceptibility to Gentamicin and Erythromycin and high resistance to Penicillins and Cephems. Staphylococci, E. coli, Streptococci and Klebsiella were implicated in subclinical mastitis. The isolates demonstrated multidrug resistance and the potential for transmission of resistant bacteria in milk to human might occurs.

Keywords: Bovine subclinical mastitis, molecular evolution, antibiotic resistance.