STUDIES ON THE BACTERIAL COMMUNITIES ASSOCIATED WITH COCKROACH (Periplaneta americana) SAMPLED FROM INDOOR SPACE AND THEIR ANTIBIOTIC RESISTANCE

Abstract

Indoor cockroaches are potential carriers of pathogenic and antibiotic-resistant bacteria. This study examined bacteria present on the external surfaces of Periplaneta americana collected from indoor environments in Malappuram District, Kerala, India, and evaluated their antibiotic resistance profiles. Bacteria were isolated using a blood agar contact method and identified through morphological, biochemical, and 16S rRNA gene sequencing analyses. Antibiotic susceptibility was assessed using the Kirby–Bauer disk diffusion method following CLSI guidelines. Two Gram-negative bacteria, Serratia marcescens and Shimwellia blattae, were consistently isolated, each showing 99% sequence similarity with reference strains. Both isolates exhibited multidrug resistance, with reduced susceptibility to penicillin G, tetracycline, cefalexin, azithromycin, streptomycin, and amoxicillin. These findings demonstrate that indoor P. americana can harbor multidrug-resistant bacteria, underscoring the need for improved sanitation and integrated pest management to reduce potential public health risks.