Bacterial Communities Associated with Retail Alfalfa Sprouts

Abstract

Fresh produce, including salad, is increasingly implicated in foodborne outbreaks. Although studies have been carried out to detect specific human pathogens from fresh produce, the total bacterial community associated with fresh produce is poorly understood. In this study, we characterized the bacterial community associated with alfalfa sprouts, using a culture-independent method. Four retail-purchased alfalfa sprout samples were obtained from different producers, and the bacterial community associated with each sample was determined by 16S rDNA profiling. Our results indicate that alfalfa sprouts sampled in our study shared significant similarities in their bacterial communities. Proteobacteria was the dominant phylum detected from all alfalfa sprout samples, with Enterobacteriaceae, Oxalobacteraceae, Moraxellaceae, and Sphingomonadaceae as the most frequently detected families. These results indicate that growth conditions of alfalfa sprouts should be taken into consideration to prevent the proliferation of pathogenic proteobacteria such as Escherichia coli O157 and Salmonella.

Metagenomic Analysis of Total Microbial Diversity and Antibiotic Resistance of Culturable Microorganisms in Raw Chicken Meat and Mung Sprouts (<i>Phaseolus aureus</i>) Sold in Retail Markets of Mumbai, India

“…This suggests sufficient sampling with total microbial flora being represented by identified phyla and genera. Similar curves have been reported earlier for alfalfa sprout and chicken caeca microflora 30,31 . Chicken had higher bacterial diversity and species richness than mung sprout.…”

“…There are very few reports on microbiological diversity of different food samples studied by HT-NGS. Moreover, the available reports on metagenomics have identified limited microbial diversity in alfalfa sprouts, chicken caeca, gut 30,43,44 without much emphasis on pathogenic nature. V3 region was targeted and the total microbial diversity characterized up to species level.…”

“…In mung, bacterial distribution was uneven with microflora like Proteobacteria, Gammaproteobacteria, Enterobacteriales and Enterobacteriaceae being most dominant, represented by >71% OTUs. High prevalence of Enterobacteriaceae in mung is due to moist humid conditions during sprouting which favours proliferation of bacteria 30 . Chicken harbouring Enterobacteriaceae, Moraxellaceae, Pseudomonadaceae, Aeromonadaceae, Staphylococcaceae, Clostridiaceae, Campylobacteraceae, Vibrionaceae could be a source of spread of food-borne pathogens (Supplementary Table S7 46 .…”

“…To analyse MAR patterns in food microflora, 50 AR colonies per food type were isolated, purified and antibiotic susceptibility test was carried out thrice following Clinical and Laboratory Standards Institute (CLSI) guidelines by using commercial antibiotics (g or units/disc) (Himedia Laboratories, Mumbai, India), viz. bacitracin (10 units), ciprofloxacin (5), chloramphenicol (30), cefotaxime (30), doxycycline (30), erythromycin (15), gentamicin (50), kanamycin (5), neomycin (30), penicillin G (10 units), rifampicin (30), streptomycin (25) and trimethoprim (10) 20,21 . Also, the minimum inhibitory concentration (MIC) of the above antibiotics for 18 pathogenic micro-organisms representing different genera was determined by broth microdilution method according to CLSI guidelines.…”

Flow cytometry for rapid detection of Salmonella spp. in seed sprouts

“…Plating experiments indicated that the microbiological quality and character of the sprout samples we used in this work were typical of this food, as reported previously [3,32,33,34,35]. Specifically, mesophilic plate counts for three separate packages of retail alfalfa sprouts sampled over a period of 4 months ranged from 3. .…”