Antibiogram and Virulence Characteristics of Multi-drug Resistant Staphylococcus aureus from Nasal Cavity of Healthy Students of Niger Delta University, Amassoma, Bayelsa State, Nigeria DC24-DC29
Dr. Adebola Onanuga,
Department of Pharmaceutical Microbiology and Biotechnology, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.
Introduction: Nasal carriage of Staphylococcus aureus (S.aureus) in healthy population has been reported to be a significant risk factor for the development of severe infections with limited clinical treatment options. This is due to the increasing emergence of Multidrug resistance (MDR) which is posing a serious health problem in the society.
Aim: To determine the antibiogram and virulent characteristics of nasal S. aureus by accessing its antibiotic resistance profile and pathogenic potentials among healthy students of Niger Delta University, Bayelsa State, Nigeria.
Materials and Methods: Four-hundred healthy University students were screened for nasal carriage of S. aureus from April to October 2016 using conventional standard techniques. The suspected S. aureus isolates were screened for the presence of nuc and mecA genes for confirmation of S. aureus and Methicillin-resistant S. aureus (MRSA) respectively using Polymerase Chain Reaction (PCR). Antimicrobial susceptibility patterns of confirmed isolates were determined using Kirby-Bauer diffusion technique. Phenotypic expressions of haemolysin and biofilm production among the isolates were determined using Blood-Agar and Congo Red Agar tests.
Results: The prevalence of nasal carriage of S. aureus was 47 (11.8%). Thirty-seven (37/47; 78.7%) and 30 (30/47; 63.8%) of the isolates were haemolysin and biofilm producers respectively. The biofilm producing S. aureus isolates were found to be significantly higher in the males than the females (Odds ratio=2.394; ?2=5.474; p=0.019). No isolate possessed mecA gene but 31 (66%) S. aureus were phenotypic MRSA. The S. aureus isolates exhibited high rates of resistance to erythromycin (87.2%), co-trimoxazole (85.1%), tetracycline (83%), ciprofloxacin (74.5%), amoxicillin/clavulanic acid (51.1%) and low rates to gentamycin (36.2%), and levofloxacin (6.4%). The prevalence of MDR among the isolates was 41 (87.2%) and the most prominent phenotypic antibiogram combinations among the isolates were “E, SXT, TE” and “CIP, SXT, TE”.
Conclusion: The high prevalence of virulent and MDR S. aureus among these healthy individuals may lead to their potential spread in the community thereby constituting a serious health concern.