Bangladesh Journal of Microbiology 

About: Bangladesh Journal of Microbiology is an academic journal published by Bangladesh Journals Online. The journal publishes majorly in the area(s): Fecal coliform & Fermentation. It has an ISSN identifier of 1011-9981. It is also open access. Over the lifetime, 264 publications have been published receiving 1325 citations.

Antibacterial Activity of Ethanol Extract of Betel Leaf (Piper betle L.) Against Some Food Borne Pathogens

Abstract: The ethanol extract of Betel leaf ( Piper betle L.), an indigenous climber plant of Bangladesh was screened for its antibacterial activity against some foodborne pathogens viz. Vibrio cholerae ATCC 6395 , E. coli ATCC 25922 , E. coli O157:H7 NCTC 12049, Shigella dysenteriae- 1 MJ-84 and Staphylococcus aureus ATCC 25923. Experimental findings revealed that the ethanol extract of betel leaves potentially inhibit the growth of these foodborne pathogens. Minimum inhibitory concentration (MIC) was ranged from 0.625% (w/v) to 0.75% (w/v). The ethanol extract of betel leaf showed the highest MIC values for E. coli ATCC 25922 (0.625 mm), Vibrio cholera ATCC 6395 (0.625 mm), and Staphylococcus aureus ATCC 25923 (0.625 mm). It was revealed that the antibacterial activity was highest at around neutral pH and at moderate temperature. The highest temperature (100°C) and the pH (10.0) treated ethanol extract showed a little less activity than the maximum activity at moderate temperature and at neutral pH, suggesting that the ethanol extract of the betel leaf was to some extent high temperature and high pH tolerant. The ethanol extract of betel leaf might have a potential application as natural food preservative to improve the microbiological safety of the foods. DOI: http://dx.doi.org/10.3329/bjm.v28i2.11817 Bangladesh J Microbiol, Volume 28, Number 2, December 2011, pp 58-63

Multiple-Antibiotic Resistance Mediated by Plasmids and Integrons in Uropathogenic Escherichia coli and Klebsiella pneumoniae

Abstract: Antibiotic resistance in urinary tract infection (UTI) is a growing public health problem in the world. In this study, a total of 182 uropathogens were isolated from patients with symptoms of urinary tract infection (UTI). Escherichia coli (88%) was the most prevalent isolate, while Klebsiella pneumoniae was recovered from 12% cases. The male/female ratio was 1:3. About 56% female and 51% male patients belonged to the age group >40 years. The antibiotic resistance rates of the isolates to fifteen different drugs were investigated. E. coli and K. pneumoniae showed variable pattern of susceptibility. The percentage of resistance to different drugs was higher in E. coli isolates compared to that of K. pneumoniae . Among the total number of isolates about 87% were resistant to at least three commonly used antibiotics. All the isolates were sensitive to imipenem. Analysis of the plasmid DNA had shown that the plasmid pattern was very diverse in both E. coli and K. pneumoniae. All the isolates contained multiple numbers of plasmid ranging from 1.0 to >140 MDa. Middleranged plasmids (30 to 80 MDa), the transferable resistance plasmids, were found to be present in 86% E. coli and 85% K. pneumoniae isolates. The strong association observed between plasmid profiles and drug resistance patterns suggest that plasmids other than the common plasmids may have epidemiological significance. The presence of class 1 and class 2 integrons were also investigated. A relatively high occurrence of class 1 integrons, that are associated with lateral transfer of antibacterial resistance genes, was observed in K. pneumoniae (88%) than in E. coli isolates (54%). Class 2 integrons were not found in any of the E . coli and K. pneumoniae isolates. These results show the high rate of drug resistance and the presence of high rate of transferable elements in these MDR isolates.

Microbial Degradation of Petroleum Hydrocarbon

Abstract: The present research was undertaken to isolate and characterize petroleum hydrocarbon degrading microbes from ship-breaking yards at Vatiary and Kumira coast in Chittagong. Twenty different petroleum hydrocarbon contaminated composite samples were collected and the total bacterial count was found to vary between 2.7×10 3 cfu/ gm and 1.77×10 7 cfu/ gm. Ten isolates were finally selected through secondary screening by Bushnell-Hass mineral salt medium using kerosene, diesel and engine oil as carbon source. They were provisionally identified and found closely related to the species Listeria monocytogenes , Staphylococcus aureus, Pseudomonas alcaligenes, Listeria grayi, Bacillus pasteurii, Bacillus badius, Bacillus cirroflagellosus, Bacillus circulans, Bacillus brevis and Citrobacter freundii . Greasy spot test was used as the primary indicator of microbial degradation of kerosene, diesel and engine oil. A more specific experiment was carried out to estimate the rate of degradation by the isolates. The highest (96.8%) degradation of diesel was shown by B. brevis , followed by 92%, 88.8% and 84.8% of diesel degradation by the strains of P. alcaligenes , B. cirroflagellosus and C. freundii , respectively. The highest degradation of kerosene (78.26%) and engine oil (43.97%) by S. aureus and L. monocytogenes respectively, were also observed. Keywords: Microbes; Petroleum hydrocarbon; Degradation DOI: http://dx.doi.org/10.3329/bjm.v27i1.9161 BJM 2010; 27(1): 10-13

Antifungal Activity of Forty Higher Plants against Phytopathogenic Fungi

Abstract: Ethanolic extract of 40 higher plants representing 23 families were tested for antifungal activity against some phytopathogenic fungi. The two most active plants showing potent antifungal activity were Acorus calamus and Piper betel . The rhizome extract of A. calamus exhibited highest antifungal activity inhibiting the mycelial growth completely (100%) against all the 6 test pathogens. P. betel exhibited more than 50% inhibition against most of the test fungi. The ethanolic extract of several higher plants could be used as alternative source of antifungal agents for protection of plants or crops against fungal infection. Keywords: Antifungal activity, Phytopathogenic fungi, Higher plants DOI: http://dx.doi.org/10.3329/bjm.v24i1.1245 Normal 0 false false false MicrosoftInternetExplorer4 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 76-78

Plasmid Curing of Escherichia coli Cells with Ethidium Bromide, Sodium Dodecyl Sulfate and Acridine Orange

Abstract: The plasmid eliminating abilities of acridine orange, ethidium bromide and sodium dodecyl sulfate were investigated on multi drug resistant Escherichia coli from urinary tract infection specimens. Three different concentrations of each curing agent (Et-Br, SDS and AO) were used. The frequencies of cured cells were 5.55 % (with 50 μg/ml) and 11.76 % (with 75 μg/ml) for acridine orange, 14.29 % (with 100 μg/ml), 21.05 % (with 100 μg/ ml), 17.65 % (with 125 μg/ml) for ethidium bromide and 7.4 % (with 10 % w/v) & 6.67 % (with 10 % w/v) for sodium dodecyl sulfate. However, no cured cells were obtained from 100 μg/ml acridine orange, 75 μg/ml ethidium bromide and 8 and 12 % SDS. Analysis of profiles of wild type and plasmid cured strains by electrophoresis yielded bands of varying sizes for wild type cells, but none were obtained for Et-Br cured cells. Acridine orange treated cells could eliminate only plasmids of 2.7 MDa and another smaller than 2 MDa. Key Words: Plasmid curing; Escherichia coli ; Ethidium Bromide; Sodium Dodecyl Sulfate; Acridine Orange. DOI: http://dx.doi.org/10.3329/bjm.v27i1.9165 BJM 2010; 27(1): 28-31