Farhana Jahan
Upazilla Livestock Office, Chandpur Sadar, Chandpur, Bangladesh;
A. T. M. Mahbub-E-Elahi
Department of Microbiology &Hygiene, Sylhet Agricultural University, Bangladesh
A. B. Siddique
Department of Microbiology &Hygiene, Sylhet Agricultural University, Bangladesh
Total viable count, Conventional beef, Public health hazard, Food borne infection, Intoxication
Seven major markets (Shibgonj, Mirabazar, Kazitula, Ambarkhana, Madina market, Bandar bazar and Sheikh ghat) of Sylhet Sadar
Postharvest and Agro-processing
Fresh and processed food
Sample collection: Seventy five samples of fresh cattle meat (beef) were randomly purchased from 7 major markets (Shibgonj, Mirabazar, kazitula, Ambarkhana, Madina market, Bandar bazar and Sheikh ghat) of Sylhet Sadar. These were collected from different portions of carcasses. During the study period of October, 2011 to December, 2011, the samples were collected twice from each market. The samples were aseptically collected in different clean polyethylene bags and were transferred immediately to the laboratory for bacteriological quality assessment as described in FAO Corporate Document Repository (2007).
Culturing, enumeration and isolation of bacteria: All the chemicals and reagents used were of analytical grade, obtained from Hi-media Laboratories Pvt. Limited, India. Media used in this study included: Nutrient Agar (NA) and Peptone Water (PW) as general and enriched media. Other media with selective and differential characteristics used were Violet Red Bile Agar (VRBA), Mannitol Salt Agar (MSA), Eosin Methylene Blue (EMB), Salmonella-Shigella (SS) Agar, Brilliant Green Agar (BGA), Blood Agar (BA), Mac Conkey Agar (MCA) etc. All media were prepared according to the manufacturer’s specification and sterilized at 121°C and 15 lb pressure for 15 min. Total viable aerobic bacteria count was performed on Nutrient Agar. For this-Meat sample (10 gram meat+ 90 ml sterile distilled water) were homogenized in a sterile blender (first dilution). One ml from first dilution (101) was transferred to second test tube (test tube contains 9 ml. of sterile distilled water) (2nd dilution or 102) so on up to the 6th dilution. Then, inoculation of sample was done. Inoculation of sample was done by pipetting 1 ml from 3rd dilution and was transferred to the sterile petridish, also from the 4th dilution to another sterile petridish up to the 6th dilution. The inoculation was followed by the pour plate method, where the sample was first put into the petridish and 15 ml agar (liquefied in a water bath at 44-46°C) were poured into the plate afterwards. Agar and sample were thoroughly mixed by rotating the petridish. After that, incubation for 24 hours at 37°C and counting of normal plates of 25-250 colonies were carried out. The counts for each plate were expressed as colony forming unit of the suspension (cfu/g). Discrete colonies were sub cultured into differential and selective media aseptically to obtain pure cultures of the isolates. Pure isolates of the resulting growth were then stored at 4°C.
Identification of bacterial isolates: Colonies identifiable as discrete on the selective media were carefully examined macroscopically for cultural characteristics such as the shape, color, size and consistency. Bacterial isolates were characterized based on microscopic appearance, colonial morphology and Gram’s staining reactions as well as appropriate biochemical tests i.e. Lysine Iron Agar (LIA) test, Triple Sugar Iron (TSI) test, Indole production test, Methyl Red (MR) test, Voges-Proskauer (VP) test, Citrate utilization test, Catalase test and Carbohydrate fermentation test as described by Buxton and Fraser (1977), Cheesbrough (1985) and Carter et al. (1995) were carried out. The isolates were identified by comparing their characteristics with those of known taxa, as described by Bergey’s Manual for Determinative Bacteriology (Buchanan and Gribbons, 1974). Data were analyzed statistically using the general linear model procedure.
The Agriculturists 13(2):09-16 (2015) ISSN 2304-7321 (Online), ISSN 1729-5211 (Print) A Scientific Journal of Krishi Foundation
Journal