Bacteriological and Antibiogram Profile of Cellulitis Infection in Khyber Pukhtunkhwa

Abstract

Cellulitis, a common skin and soft tissue infection, poses significant health risks if not properly managed. This study aimed to investigate the bacteriological profile and antibiotic susceptibility patterns of pathogens isolated from cellulitis patients in Khyber Pakhtunkhwa, Pakistan, and evaluate the antibacterial potential of Bacillus-derived secondary metabolites against Staphylococcus aureus. A total of 25 pus swab samples were collected from patients admitted to Lady Reading Hospital, Peshawar, and Bacha Khan Medical Complex, Swabi. Of these, 21 showed positive bacterial growth upon primary culturing. The isolated bacteria were identified using standard morphological and biochemical tests, revealing Escherichia coli (9.5%), Streptococcus spp. (33.3%) and Staphylococcus aureus (57.1%) as the most prevalent pathogen. Antibiotic susceptibility testing was conducted using the disc diffusion method on Mueller-Hinton Agar. Results indicated that S. aureus isolates were most susceptible to Gentamicin, Fosfomycin, and Nalidixic Acid, while showing resistance to Ciprofloxacin and Amikacin. Streptococcus spp. demonstrated sensitivity to Ciprofloxacin, Nalidixic Acid, and Fosfomycin, whereas E. coli was sensitive to all tested antibiotics. The antibacterial activity of secondary metabolites extracted from Bacillus species was assessed using the agar well diffusion method. The highest activity was observed in the 15 mL chloroform extract, followed closely by the pure extract with DMSO. Lower activity was noted in aqueous and diluted chloroform extracts, while Ciprofloxacin served as a positive control and DMSO showed no activity. These findings underscore the prevalence of antibiotic-resistant bacteria in cellulitis and highlight the moderate antibacterial potential of Bacillus-derived metabolites, suggesting their possible role in future therapeutic development. KEYWORDS Cellulitis; Bacillus specie; Staphylococcus aures