Evaluation of Ready-to-eat Polyethylene Packed Pawpaw (Carica papaya) for the Presence of Antibiotic Resistant Escherichia species

Aims: The study examined ready-to-eat cut polyethylene packed pawpaw (Carica papaya) sold in the University of Port Harcourt community for the presence of antibiotic resistant Escherichia species.

Study Design: The samples were randomly purchased from vendors, who openly display them in trays and composite analysed in duplicate.

Place and Duration of Study: Department of Microbiology, University of Port Harcourt between January and June 2015.

Methodology: A total of 50 ready-to-eat polyethylene packed pawpaw were examined for the presence of presumptive E. coli 0157:H7 and non-0157:H7 E. coli, using MacConkey-Sorbitol agar and eosin methylene blue agar. Isolated were confirmed on the basis of cultural morphology, physiology and biochemical characteristics. Screening for antibiotic susceptibility was done using the disk diffusion method involving Mueller Hinton agar.

Results: Of the 50 samples examined, 34 (68%) were positive for Escherichia species, with counts ranging from 1.6 to 3.5 ×104 cfu/g. Presumptive 0157:H7 E. coli accounted for 5.88% while non-0157:H7 E. coli accounted for 94.12%. The resulting isolates showed varying resistance to augumentin (5.88%), amoxicillin (97.06%), cloxacillin (73.53%), cotrimoxazole (95.58%), erythromycin (5.88%), gentamicin (14.71%), nitrofurantoin (85.29%) and tetracycline (58.82%).

Conclusion: The study clearly reveals that consumption of ready-to-eat cut pawpaw from vendors can be a potential risk for food borne outbreaks because of their contamination level by E. coli and the variable resistance patterns in response to different antibiotics used in the study.