Pages: (140-149 )
Abstract
This study investigated the microbial load of fresh produce retailed in Umuahia, Nigeria, and assessed the prevalence and antibiotic resistance of Salmonella. The loads of bacteria and coliforms as well as presence of Salmonella in 42 fresh produce samples were determined by standard microbiological methods. Antimicrobial susceptibility profile of the Salmonella isolates was determined using disc diffusion assay, while the multidrug resistant isolates were assessed for tolerance to different concentrations of acetic acid (0.5-5%) and NaCl (1-5%). The total bacterial and coliform counts ranged from 7.42 to 8.59 and 4.75 to 6.53 log10CFUg-1, respectively. Salmonella was detected in 30 (71.43%) samples. All 24 Salmonella isolates (100%) were resistant to amoxicillin, augmentin, cefuxoxime, cefuroxime and ceftazidime, while absolute susceptibility (100%) was only recorded for ofloxacin. Nine resistance patterns were demonstrated by the isolates, being resistant to at least 5/10 antibiotics and at most 8/10 antibiotics. All selected multidrug resistant isolates except Salmonella sp. cror1 survived in 5% NaCl, while no growth was observed for 7/8 isolates in 1.5% acetic acid. The high prevalence of Salmonella in retailed fresh produce and high frequency of multidrug resistance amongst the isolates suggest the need for increased awareness about hygienic practices and effective regulation of medically important antimicrobials.
Keywords: Antibiotics resistance, Fresh produce, Salmonella, Food Safety,