Evaluation of Microbial Loads on Dried and Fresh Shiitake Mushrooms (Lentinula edodes) as Obtained from Internet and Local Retail Markets, Respectively.

Consumer demand for shiitake mushrooms is increasing. However, food safety information regarding the prevalence of microbial pathogens on the products sold via the Internet or at local retail markets is limited. The present study was conducted to assess the microbial load on shiitake mushrooms sold through the Internet and at local (central Virginia) retail markets. A total of 90 shiitake mushroom products, consisting of locally-purchased whole (LW) and sliced (LS) and Internet-procured whole (IW), sliced (IS), and powdered (IP) forms, were tested. High levels of aerobic mesophiles (6.9 ± 1.3 to 7.5 ± 1.1 log CFU/g), yeast and mold (5.8 ± 0.9 to 6.0 ± 0.3 log CFU/g), and coliforms (1.6 ± 1.0 to 1.9 ± 1.1 log MPN/g) were found in locally-acquired mushrooms. One LW sample and 2 of LS contained Listeria spp. Our findings suggest that shiitake mushroom producers and retailers need to be aware of potential microbial hazards associated with handling fresh shiitake mushrooms and consumers should take appropriate precautions when handling fresh shiitake mushrooms to prevent cross-contamination and possible foodborne illness in the home.

Comparison of the Microbial Quality of Lamb and Goat Meat Acquired from Internet and Local Retail Markets.

This study was conducted to evaluate the microbial quality of lamb and goat meat sold through local (Virginia) and Internet (U. S.) retail markets. A total of 134 frozen meat products consisting of locally purchased lamb ground (LLG) and lamb chops and Internet-procured lamb ground, goat ground, lamb chops (ILC), goat chops (IGC), lamb stew, and goat stew were tested. Significantly higher levels of aerobic mesophiles, psychrotrophs, and coliforms were found in the meat locally acquired than in the meat procured from the Internet. Similar average prevalence (27%) of Escherichia coli was observed regardless of market source. Ground meat had significantly high levels and prevalence of mesophiles, psychrotrophs, coliforms, and Listeria spp. One sample of LLG contained Campylobacter, and one sample of IGC contained Salmonella. Listeria spp. were present in 23 to 40% and 17 to 80% of samples from local and Internet markets, respectively. Pulsed-field gel electrophoresis (PFGE) of isolated E. coli strains revealed brand specificity and genomic diversity. No isolate from different brands and market sources had matching PFGE profiles. The average price of Internet meat ($23.4/kg) was about 1.2 times higher than the price of local meat, except for ILC, whose price was 2.7 times higher. This study revealed differences in microbial quality of lamb and goat meat based on market source; thus, meat products should be handled carefully regardless of market source because of the presence of high microbial levels and the high prevalence of pathogens.