ABSTRACT
Aims: Search for novel antimicrobials such as bacterial pigments is an issue of priority now. This study aims to isolate pigments with anti-bacterial activity from soil bacteria. Methodology: In this study, Pigment forming bacteria was isolated from soil samples collected from different sites of Dhaka city and its adjoining areas. Colonies of various colors such as yellow, golden yellow, red, pink, blue, green, purple and cream with both diffusible and non-diffusible pigments were isolated in pure cultures on nutrient agar plus 2 percent glycerol at pH 7.2 and 37ºC. Anti-bacterial activity of the pigments extracted from the bacteria were determined. Results: 15 pigment forming bacteria was isolated from soil and identified to genus level as Pseudomonas, Flavobacterium, chromobacterium, Xanthomonas, Aeromonas, Escherichia and Bacillus. All the pigments showed to be broad spectrum in terms of inhibitory activity against all the pathogens included in this study. Most of the pigments showed better anti-bacterial activity against gram-negative bacteria. Highest zone of inhibition was resulted by pigment no 15 against Salmonella typhi and lowest zone of inhibition was observed for pigment 13 against Staphylococcus aureus. Most of the pigments except four (pigment no- 3, 10, 12, 15) were found to be bacteriostatic to the test pathogens. MIC value of the pigments ranged from 1500-4000 μg/ml and most of the pigments showed lower MIC value against gram-negative organisms. Conclusion: On the basis of anti-bacterial activity and minimum inhibitory concentration (MIC) pigment form Aeromonas (no- 6), Escherichia (no-10) and Pseudomonas (no-15) can be selected as effective anti-bacterial agent. Further studies are needed to use these pigments in food, cosmetic and textile industries.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the bacterial load and antibiotic resistance pattern of bacterial isolates obtained from (ready to cook) frozen food samples of animal origin in Dhaka, Bangladesh.</p><p><b>METHODS</b>A total of 20 samples of frozen ready to cook food of animal origin were purchased from different separate grocery stores in Dhaka, Bangladesh. Bacteria were isolated and identified based on the basis of biochemical properties.</p><p><b>RESULTS</b>A total of 57 isolates has been isolated from 20 samples, of them 35.08% were Gram positive and 64.92% were Gram negative organisms. Highest percentages of isolated organisms were Staphylococcocus spp. (24.56%), Alcaligene spp. (17.54%), Klebshiella spp. (12.28%) and the lowest percentages of organisms were Enterococcus spp., Actinobacillus spp. and Proteus spp. Antibiogram results clearly showed that levofloxacin and imipenem were the most effective drug against the isolates. The less effective antibiotics were chloramphenicol and nalidixic acid and resistance was highest against ciprofloxacin. The most contaminated food was chicken nuggets.</p><p><b>CONCLUSIONS</b>This type of frozen food contaminated with multi-antibiotic resistant microorganisms can be potential vehicles for transmitting food-borne diseases.</p>
ABSTRACT
Objective: To investigate the bacterial load and antibiotic resistance pattern of bacterial isolates obtained from (ready to cook) frozen food samples of animal origin in Dhaka, Bangladesh. Methods: A total of 20 samples of frozen ready to cook food of animal origin were purchased from different separate grocery stores in Dhaka, Bangladesh. Bacteria were isolated and identified based on the basis of biochemical properties. Results: A total of 57 isolates has been isolated from 20 samples, of them 35.08% were Gram positive and 64.92% were Gram negative organisms. Highest percentages of isolated organisms were Staphylococcocus spp. (24.56%), Alcaligene spp. (17.54%), Klebshiella spp. (12.28%) and the lowest percentages of organisms were Enterococcus spp., Actinobacillus spp. and Proteus spp. Antibiogram results clearly showed that levofloxacin and imipenem were the most effective drug against the isolates. The less effective antibiotics were chloramphenicol and nalidixic acid and resistance was highest against ciprofloxacin. The most contaminated food was chicken nuggets. Conclusions: This type of frozen food contaminated with multi-antibiotic resistant microorganisms can be potential vehicles for transmitting food-borne diseases.