Bacteriological Profile and Antibiotic Sensitivity Patterns of Deep Neck Space Infections in Tertiary Institutions in South West Nigeria

Deep neck space infections (DNSIs) are life-threatening polymicrobial infections that may originate from dental sources, pharyngeal infections, or trauma, requiring prompt surgical drainage and targeted antimicrobial therapy. In South West Nigeria, empirical antibiotic prescribing for DNSIs is common due to limited access to rapid microbiological diagnostics, but the appropriateness of these empirical choices has not been validated against institutional bacteriological data. This prospective analytical study determines the bacteriological profile and antibiotic sensitivity patterns of DNSI pathogens isolated from surgical drainage specimens at three tertiary institutions in Ogun, Lagos, and Osun States, over a 30-month study period. Purulent specimens from 88 consecutive DNSI patients were cultured using standard aerobic and anaerobic protocols, and antibiotic sensitivity testing was performed using the Kirby-Bauer disc diffusion method. Mixed polymicrobial infections were identified in 61.4% of specimens. The most common isolates were Streptococcus viridans, Staphylococcus aureus, Prevotella species, and Fusobacterium nucleatum. Methicillin-resistant Staphylococcus aureus (MRSA) was identified in 14.8% of Staphylococcal isolates. Sensitivity to amoxicillin-clavulanic acid and metronidazole was 74%, while clindamycin resistance was present in 38% of anaerobic isolates. The study provides the first multi-centre bacteriological dataset for DNSIs in South West Nigeria and strongly recommends mandatory microbiological culture for all surgically drained deep neck infections to guide rational antibiotic therapy. Keywords: deep neck space infections, bacteriology, antibiotic sensitivity, South West Nigeria, polymicrobial.