Dominic Agbo OCHEB. BSc. (UDUS) 20122023-09-212023-09-212020-01-16https://teras.ng/api/asset/document/23f914fc-1daa-4202-bdb1-6fe1ba57cc23https://teras.ng/catalog-item/60507fa3-bbb6-44a9-9c12-91a8e540b94dhttp://dspace.teras-network.net:4000/handle/123456789/16571Staphylococcus aureus is a Gram-positive pathogens causing a wide range of health-care and community acquired infections. Its ability to form small-colony variants (SCV), biofilm and acquire resistant genes have resulted in its persistence in patients and also putting health-care workers at risk. This study evaluated the antibiotic resistance profile and biofilm forming capacity of S. aureus isolated from clinical samples of hospitalized patients in National Orthopaedic Hospital Dala (NOHD), Kano, Nigeria. A total of 189 samples consisting of 49 wound swabs, 49 nasal swab, 49 bed swab and 42 urine samples were collected over a period of 3 months. These samples were cultured on mannitol salt agar (MSA) and the isolates were subjected to Gram staining, catalase test, and coagulase test. And the coagulase positive isolates were further screened using Staphylococcal Microgen identification kit to identify S. aureus isolates. A total of 28 S. aureus were identified from the189 clinical samples collected. The S. aureus isolates were screened for small-colony variants (SCVs) by culturing the isolates on Columbia blood agar (CBA) to detect pin-point or tiny colonies that are non-haemolytic and non-pigmented and they were evaluated for biofilm-formation using the microtiter plate (MTP) method. Also, antibiotics susceptibility pattern and inducible clindamycin (D-test) resistance of the S. aureus isolates were determined using the agar disc diffusion method. Molecular analysis of the isolates was done to determine the presence of biofilm associated genes (icaA and bbp) and antibiotics resistance genes (mecA and vanA) in the S. aureus isolates using polymerase chain reaction (PCR) to amplify the genes if present. Of the 189 samples collected, 28 (14.3%) were confirmed to be S. aureus. Biofilm production was observed in 27 (96.4%) of the S. aureus isolates with 1 (3.6%) S aureus isolate as non-biofilm producer. From the biofilm producers, 3 (10.7%) of the biofilm-producing isolates were strong biofilm-formers, 6(21.4%) were moderate biofilm-formers and 18 (64.3%) were weak biofilm-formers. Antibiotics susceptibility showed that the S. aureus isolates were generally resistant to Amoxicillin-Clavulanic (67.9%), Tetracycline (67.9%), Ciprofloxacin (67.9%), Norfloxacin (64.3%), Cefoxitin (67.9%), Clindamycin (57.1%) and Gentamicin (53.6%). But they were significantly susceptibility to Linezolid (85.7%), Mupirocin (64.3%), Erythromycin (53.6%), Trimethoprim-Sulfamethoxazole (57.1%) and Quinipristin- Dalfopristin (60.7%). High percentage (85.7%) of the S. aureus isolates had MAR index˃ 0.2, and 85.7% of the isolates were multi-drug resistant (MDR) also. A total of 2 (7.1%) S. aureus isolates tested positive for inducible clindamycin resistance and 57.1% showed constitutive clindamycin resistance. The high-level mupirocin resistance was found in 21.4% of the isolates while the low-level mupirocin resistance was found in 25% of the isolates. Molecular analysis of these isolates showed that 30% harboured icaA gene that was amplified at 188bp, 37.5% harboured bbp gene that was amplified at 500bp, 33.3% harboured mecA gene that was amplified at 533bp and 20% harboured VanA gene that was amplified at 1030bp.Post Graduate Theses