Characterization of antimicrobial resistant bacterial pathogens recovered from cases of bovine mastitis with special reference to Staphylococcus aureus

Abstract EN

In this study a total of 20 and 78 milk samples were collected from animals showed clinical and subclinical mastitis criteria respectively for isolation and identification of different pathogens causing clinical and subclinical mastitis in some dairy farms of Beni-Suef Governorate, and investigation of their in vitro sensitivity.

The most prevalent microorganisms recovered were Staphylococcal species (no=79, 80.61%) followed by Enterococcus spp.

(n=28, 28.57%), CAMP negative Streptococci, Pseudomonas aeruginosa (n=7, 7.14%), E.

coli (n=3 ,3.06%) and Proteus vulgaris (n=1 ,1.02% ).

Antibiogram profile for S.

aureus showed that the most effective drug was vancomycin and the least effective drug was penicillin.

In this study also trials were done to detect biofilm production for the recovered isolates of S.

aureus (n=23) by means of phenotypic method named as Congo red agar method (CRA) and genotypic methods by determination of some biofilm related genes by means of PCR.

All the recovered S.

aureus isolates were seeded on the CRA media to detect their biofilm forming ability.

All the tested isolates showed biofilm forming ability either strong or intermediate.

13 (56.52%) of them were strong biofilm producers, while 10 (43.48%) were intermediate biofilm producers.

Detection of some biofilm associated genes (icaA, icaD and bap genes) using polymerase chain reaction revealed that two isolates out of 19 (10.53%) were negative for all the tested genes, 16 isolates (84.21%) harbored both icaA and icaD gene while only one isolate harbored all the tested genes (5.26%)