Comparative Study on Isolation and Characterization of Various Bacteria Isolated from the Oral Swabs of Healthy and Dental Patients in Dera Ismail Khan

Abstract

Oral diseases such as dental caries and periodontitis are strongly associated with microbial dysbiosis and increasing antibiotic resistance, posing a significant public health challenge. Understanding shifts in oral microbiota, related risk factors, and resistance trends is essential for effective disease management. This study aimed to compare oral bacterial flora between healthy individuals and dental patients, assess associated behavioral and socioeconomic risk factors, and evaluate antibiotic resistance patterns of isolated bacteria. A comparative cross-sectional study was conducted on 120 participants (60 healthy individuals and 60 dental patients) aged 10–65 years. Oral swabs were cultured on selective and non-selective media under aerobic and anaerobic conditions. Bacterial identification was performed using Gram staining and biochemical tests. Antibiotic susceptibility was assessed using the Kirby–Bauer disk diffusion method following CLSI guidelines. Risk factors were recorded via structured questionnaires. Statistical analysis was performed using Chi-square tests and logistic regression (p < 0.05). Microbial growth was observed in 97.5% of samples, with significantly higher colony diversity in dental patients (p < 0.05). Healthy individuals predominantly harbored commensal Streptococcus species, while dental patients showed increased prevalence of pathogenic bacteria, including Streptococcus mutans (70%), Prevotella intermedia (60%), Fusobacterium nucleatum (50%), and Porphyromonas gingivalis (40%) (p < 0.001). Risk factors such as poor oral hygiene, high sugar intake, and infrequent dental visits were significantly associated with disease (p < 0.01). Antibiotic resistance was higher among dental isolates, with multidrug resistance observed in Staphylococcus aureus (55–60%). Dental disease is associated with microbial dysbiosis, behavioral risk factors, and increased antibiotic resistance. Rational antibiotic use, improved oral hygiene practices, and continuous surveillance of resistance trends are strongly recommended.