Sensitivity of Aeromonas Obtained from Poultry Sources of Dhaka, Bangladesh

About 30% poultry samples harboured Aeromonas spp. Sensitivity tests of 100 selected strains against 12 antibiotics revealed that 20 100% were resistant to nine and 18 85% were sensitive to eight antibiotics, respectively. All isolates showed multiple resistance to six to nine antibiotics and thus pose a risk for both chicken farms and public health. Aeromonads are major causative agents of infections in fish as well as in poultry (Austin and Adams 1996) and have been associated with human diarrhoeal disease, wound infections and severe dysentery (Kuhn et al. 1997). The occurrence of different Aeromonas species in foods of animal origin, especially commercially obtained meats have been reported by several investigators (Gill and Jones 1995). In Bangladesh, poultry meat and eggs are among the most important and popular dishes in the daily diet in addition to their use in many fast food items. Food contamination with antibioticresistant bacteria is a major threat to public health. Among food-borne pathogens, the prevalence of antibiotic resistant strains has increased recently (Chiu et al. 2002) because of indiscriminate use and misuse of antibiotics in food-producing animal farms (Teuber 2001). The present study was designed to isolate Aeromonas from five poultry sources of Dhaka, Bangladesh for assessing their susceptibility patterns to some common antibiotics, conventionally used in Bangladesh. A total of 150 samples, 30 from each source such as cloacal swabs and intestinal fluid of chicken, egg surface, soil of chicken market and hand wash of chicken salesman from different poultry markets of Mohakhali, New market, Mirpur and Malibag were collected. All the samples were transported to the laboratory immediately in an ice box (4 6° C). In case of samples of cloacal swab, the test tubes containing APW were incubated for 24 hr at 37° C. The isolation of bacteria was done by viable culture method using spread plating, pour plating and membrane filter technique (Akond et al. 2009). For successful isolation of typical colonies, triplicate plates of xylose deoxycholate citrate agar (XDCA) medium (Hi-Media, India) were made and incubated for 24 hr at 37o C. The isolated cultures were purified by subculture into single identical colonies. Identification was confirmed following standard morphological and biochemical tests of Buchanan and Gibbons (1974). Sensitivity tests were carried out by single disc diffusion method (Bauer et al. 1966) recommended by the Clinical and Laboratory Standards Institute (CLSI 2005). A total of 12 antibiotic discs (Becton Dickinson, U.S.A.) such as streptomycin (10 μg), erythromycin (15 μg), chloramphenicol (30 μg), ciprofloxacin (5 μg), tetracycline (30 μg), penicillin (10 μg), norfloxacin (10μg), riphampicin (5 μg), neomycin (30μg), ampicillin (10 μg), nalidixic acid (30 μg) and gentamicin (10 μg) were used. An inoculum was transferred from a single and well-isolated colony to 2 ml of Mueller-Hinton broth by a sterile inoculating loop and incubated at 37° C for 4 hr to obtain the seed culture. The turbidity of broth culture was then adjusted to a 0.5 McFarland (McFarland 1907) standard with sterile physiological saline water and then a sterile cotton swab *Corresponding author. Institute of Public Health, Mohakhali, Dhaka-1212, Bangladesh. Present address: Laboratory of Environmental Bioscience, Faculty of Agriculture, Yamaguchi University, Japan 753-8515.