Aim:The study was conducted for the isolation, identification, and antibiogram of bacteria obtained from fresh guava (Psidium guajava).Materials and Methods:A total of 25 fresh guavas were collected from five markets located in Mymensingh city. Guava samples were cultured onto various selective media such as eosin methylene blue, xylose lysine deoxycholate, thiosulfate-citrate-bile salts-sucrose, blood agar, and mannitol salt agar for the isolation of bacteria. Biochemical tests (dextrose, maltose, lactose, sucrose, mannitol, methyl red, Voges–Proskauer, and indole) were performed to identify the bacteria.Results:Total viable counts of guava were ranged between log 6.56 colony-forming unit (cfu)/ml and 6.62 cfu/ml. A total of 106 bacterial isolates belonged to five genera (Escherichia coli, Salmonella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp.) were identified. Salmonella spp. (23.6%) was the most prevalent, followed by E. coli (22.64%), Bacillus spp. (19.81%), Staphylococcus spp. (17.92%), and Vibrio spp. (16.03%). The results of antibiotic sensitivity test showed that Salmonella spp., Bacillus spp., and E. coli were sensitive to chloramphenicol, ciprofloxacin, and gentamicin and resistant to ampicillin and cephalexin. Vibrio spp. was sensitive to chloramphenicol and gentamicin, intermediately sensitive to ciprofloxacin and ampicillin and resistant to cephalexin.Conclusion:The results of this study indicate that fresh guava contains multidrug-resistant bacteria which might pose a public health risk.

Aim:The present study was undertaken to determine bacterial load as well as characterize bacterial flora of ready to eat (RTE) betel leaf sold at local markets in Mymensingh city.Materials and Methods:A total of 25 RTE betel leaf samples were collected from five local markets such as Kamal-Ranjit (KR) market, Shesh more, Kewatkhali, Jobber more, and Ganginar par.Results:Total viable count of bacteria in betel leaf (log10 mean colony forming unit±standard deviation/ml) was 7.58±0.04 for KR market, 7.72±0.06 for Shesh more, 7.62±0.04 for Kewatkhali, 7.40±0.03 for Jobber more, and 7.60±0.06 for Ganginar par. A total of 98 bacterial isolates belong to five genera (Escherichia coli, Salmonella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp.) were identified. The prevalence of E. coli was 17.34%, Salmonella spp. was 25.51%, Vibrio spp. was 19.39%, Bacillus spp. was 18.37%, and Staphylococcus spp. was 19.39%. Antibiotic sensitivity test showed that all isolates were sensitive to two antibiotics such as ciprofloxacin and gentamicin. Four isolates (E. coli, Salmonella spp., Vibrio spp., and Staphylococcus spp.) were resistant to two antibiotics (ampicillin and cephalexin). Antibiogram profile of bacterial isolates of betel leaf suggests that they were multidrug resistance.Conclusion:Data of this study indicate that betel leaf sold at local market harbors multidrug resistance food-borne bacteria which might cause public health hazards if these antibiotic resistant transfer to human through food chain.

Microplastic (MP) pollution is potentially a big threat to many aquatic organisms. However, we currently know very little about the effects of small MPs on phenotypes and the extent to which genetic and environmental factors modify the effects of MPs. I studied the direct and indirect effects of 9.5 - 11.5 μm polystyrene microspheres on the life history traits (time to maturation, total number of offspring, size of adults) of Daphnia pulex clone Bel 19 and Bel 87. The D. pulex clones were exposed to two different concentrations (low 0.001 mg/l and high 1 mg/l) of MP. Each clone had two groups of individuals. One group of individuals was fed with algae food (no MP aging) to observe direct effects, and another group with algae food (MP aging) to observe indirect effects on the life history traits. MPs were aged in algae suspension for 7 days. Individuals were fed with an amount of carbon concentration 1 mg/l. I used laboratory exposure to answer the research questions - 1) do D. pulex clones differ in the susceptibility to MP pollution in terms of life history traits? and 2) are there any signicant differences between direct and indirect effects of MPs on life history traits of D. pulex clones? The results from the study showed that the D. pulex clones differ signicantly in the susceptibility to MP pollution in terms of the observed life history traits, which demonstrate the importance of incorporating genetic variation into the assessments of the impacts of plastic particle exposure. Signicant differences were also observed between the direct and indirect effects of MP on life history traits of D. pulex clones. Among the observed traits, time to maturation is the most affected one by indirect effect with the largest effect size (almost 3 times higher than the direct effect size). The results indicate that indirect ecological effects might lead to effect thresholds at levels considered eld relevant to the direct effects