Determination of prevalence and antibiotic susceptibility pattern of the bacterial isolates collected from different parts of restaurant refrigerators of Mohakhali, Dhaka, Bangladesh

Abstract

Refrigeration is an essential food storage technique and an important link in wide chain of cross contamination which leads to the outbreak of many food borne disease. In this study samples were obtained from various parts (drawer, handle, egg tray, surface) of two restaurant’s refrigerators of Mohakhali, Dhaka, Bangladesh. A total of 41 isolates were collected from 8 different parts and identified through conventional biochemical tests according to Bergey’s Manual of Systematic Bacteriology. Antibiotic susceptibility pattern was determined by using Kirby-Bauer disc diffusion method for all the 41 isolates against nine commercial antibiotic discs [Ampicillin (10 μg), Ciprofloxacin (5 μg), Chloramphenicol (30 μg), Gentamycin (10 μg), Azithromycin (15μg), Penicillin-G (10 μg), Nalidixic acid (30 μg), Streptomycin (10μg), Tetracycline (30 μg)]. In result, Staphylococcus spp. showed the highest prevalence 11 (26.82%), followed by Salmonella spp. 7 (17.07%), Klebsiella spp. 7 (17.07%), Vibrio spp. 6 (14.63%), Bacillus spp. 4 (9.75%), Pseudomonas spp. 4 (9.75%) and E.coli 2 (4.87%) respectively. Among the 41 isolates, 43.90% were found resistant to more than two antibiotics and highest percentage of resistance was observed against ampicillin (73.17%). On the other hand only 2.43% isolates showed resistance against ciprofloxacin and gentamycin. Temperature tolerance of the organisms also determined by growing the isolates in different temperature like 45°C, 50°C and 55°C. Growth was observed for all organisms at 45°C but in 50°C, 29.26% isolates showed viable growth. In 55º C no growth was observed. These results indicate that the pathogenic bacteria can survive in refrigerator surfaces and can cause cross contamination. It is needed to maintain appropriate food storage and refrigerator management, and proper hand hygiene is recommended.