Phenotypic Study on the Capacity of Biofilm Production in Staphylococcus Aureus Isolated From Bovine Subclinical Mastitis and Their Impact on Resistance to Antimicrobials

Abstract

The study was intended for identification and characterization of Staphylococcus aureus isolated from bovine subclinical mastitis cases. A total of 143 milk samples were collected from apparently normal cows from Basrah province. California mastitis test was used to detect 81 (56.6%) samples as subclinical mastitis. However, by using bacteriological and biochemical tests 36(44.44%) isolates were confirmed as S. aureus. Antimicrobials susceptibility assays of isolates revealed that, all of them were completely susceptible to chloramphenicol, gentamycin and vancomycin. Oxacillin and cefoxitin susceptibility illustrated that 22(61.1%) isolates were resistant to methicillin (MRSA) and 14 (38.9%) isolates were methicillin susceptible (MSSA). Phenotypic production of slime and biofilm were evaluated by using Congo red agar and microtiter plate techniques, 31 (86.1%) isolates were slime producer and 29 (80.6%) were biofilm producers from all tested isolates. The production of slime and biofilm of MRSA isolates were 95.5% and 90.9%, whereas, for MSSA were 71.4% and 64.3% respectively. The differences in slime and biofilm production among MRSA and MSSA isolates were statistically significant. All MRSA isolates were resistant to oxacillin, penicillin, cefoxitin, ampicillin and cefotaxime, and these isolates showed low resistance to erythromycin and lincomycin each (9.1%) and doxycycline (18.2%). However, these isolates were susceptible to vancomycin, gentamycin, nitrofurantoin and chloramphenicol. All MSSA isolates

Isolation and molecular characterization of staphylococcus aureus isolated from clinical cases in broilers

“…In recent years, MRSA has become a particularly significant problem in many regions on the world because of its ability to getting resistance to antimicrobial drugs (84), thus, the rapid recognition of MRSA was necessary for prompting effective treatment and preventing the dissemination of infection (85). Furthermore, the prevalence of MRSA differs considerably from one region to another and among farms in the same district, the data on the prevalence of MRSA in Iraq is limited, few studies were reported different prevalence rate in chickens, and slaughterhouses as follows: 61.1% and 53.8% (86,87), and 66.6%, 20.3%, and 27.3% among chickens and attached stations for slaughterhouses and poultry fields (42,88,89). Meanwhile, the prevalenve rate of MRSA in other countries was as follow 44% among chickens carcasses in Egypt (90), 9.5% among poultry meat in Jordan (91), in Algeria the prevalence of MRSA among broilers was 20%-50% according to (62,92) while in layer chickens in Egypt the prevalence was 60% (93).…”