Production of β-Lactamase Enzyme among Normal Micro-Flora of Human Body and Determining Their Antibiotic Resistance Pattern

Owing to the variety of micro-flora population residing on human's skin and an ever-increasing expansion of antibiotic resistance in bacteria, studying the antibiotic resistance in normal microbial flora of human body (especially normal flora of the skin) is like to be necessary. In this study, 96 samples from certain area of hand or foot of selected persons was cultured using sterile swab and streak plate method in 37°C and bacteria were identified by microbiologic standard methods. Then production of β-lactamase enzyme was studied by acidometery method and antibiotic resistance profile in β-lactamase positive bacteria was determined by Kirby-Bauer method. Finally, the MIC and MBC of penicillin G were determined on bacteria with multiple antibiotic resistances. 180 microorganisms isolated from 96 samples of skin flora and 26 bacteria produced β-lactamase enzyme. All of strains with β-lactamase enzyme were detected as gram positive bacilli or staphylococci that were resistant to the most of related antibiotics. It is indicated that emerged production of β-lactamase enzyme amongst micro-flora of skin in healthy persons of the community is a result of uncontrolled entrance and consumption of penicillins and cephalosporins in medicine markets. Therefore, skin of healthy persons is considered to be one of the most important reservoirs for microorganisms causing hospital-acquired infections.