Isolation and identification of bacteria from fresh guava (Psidium guajava) sold at local markets in Mymensingh and their antibiogram profile

Abstract

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.

Keywords

• antibiogram profile
• bacteria
• guava
• identification
• isolation
• Mymensingh