M. S. Hossain
Department of Pharmacy, University of Rajshahi, Rajshahi-6205, Bangladesh.
M. A. A. Al-Bari
Department of Pharmacy, University of Rajshahi, Rajshahi-6205, Bangladesh.
M. I. I. Wahed
Department of Pharmacy, University of Rajshahi, Rajshahi-6205, Bangladesh.
Probiotic products; Lactic acid bacteria; Antibiotic susceptibility
Animal Health and Management
Five probiotic pharmaceutical preparations namely Probio (Square Pharma Ltd, Bangladesh), Prolacto (Drug International Ltd, Bangladesh), Protik Vitality (Kemiko Pharma Ltd, Bangladesh), Preotik (Meridian Medicare Ltd, India) and TS6 (TensallBio-Tech Company Ltd, Taiwan) were procured randomly from retailed pharmacy in Rajshahi division. The collected samples were stored in a refrigerator to maintain physical stability of the products. Total viable lactic acid bacteria counts in each sample were analyzed by spread plating the serially diluted samples onto the culture media, De Man, Rogosa and Sharpe (MRS) medium and nutrient broth and agar. After incubation at 15-37°C for 72 h, colonies with clear zones were counted. Some of these colonies are selected and purified on nutrient agar medium and preserved the slants for a long time.For morphological characterization of probiotic bacteria, at first all colonies were used for microscopic observations such as colony morphologies including sporulation, margin elevation, surface pigmentation, opacity, growth patterns inside, at the bottom or on the surface of the medium and the rate of growth. The colony cultures were identified according to their physiological and biochemical characteristics [11, 12]. The biochemical tests used were Gram staining; production of catalase; growth at different temperatures (15°C, 25°C, 37°C and 45°C) for 3 days; growth resistance at 60°C for 30 min (Sherman test); growth at different NaCl concentrations and different pHs (2.5-6.5); fermentation profile of different sugars such as cellobiose, dextrin, fructose, glucose, galactose, lactose, mannose, sucrose, salicin or maltose in 1% w/v, lactic acid production from 1% w/v lactose and motility [13,14]. For catalase test, in brief, growth from an overnight culture of the microbe was smeared on a microscope slide. A drop of 3% hydrogen peroxide (H 2O2 ) was added. If copious bubbles were observed, the microbe was positive for catalase otherwise negative. Colonies were characterized on nutrient and MRS agar and broth media. Strains with gram positive and catalase negative reactions were finally used for further identification [15]. Bacterial antibiotic resistance was determined on solid MRS agar by the use of nine different antibiotic discs. The results (average of 3 readings) were expressed as sensitive (S) or resistant (R) by following the standard disc diffusion method [14, 16]. Standard antibiotics such as penicillin G (10 μg), amoxicillin (30 μg), ceftriaxone (30 μg), ceftazidime (30 μg), kanamycin (30 μg), tetracycline (30 μg), streptomycin (10 μg), erythromycin (15 μg) and ciprofloxacin (5 μg) were used for this study [16, 17].
J. Sci. Res. 8 (1), 101-108 (2016), ISSN: 2070-0237 (Print); 2070-0245 (Online).
Journal