Pathogenic Listeria serovars produced hemolysis on agars containing 5% rabbit erythrocytes and 10 micrograms of acriflavin, 40 micrograms of nalidixic acid, and 7.5 activity units of equi factor per ml. Apathogenic Listeria innocua was nonhemolytic on this medium.

In the present work, inhibitory power of alcoholic extracts agro-industrial by-products orange and passion fruit was studied against four bacteria: Listeria monocytogenes, Streptococcus mutans, Salmonella spp., Escherichia coliand two fungi: Penicilliumsp, Rhizopus spp. The peels in concentrations 0,05 0,1% were applied to strains six microorganisms zone inhibition growth curve along 24 h deter...

Objective of the present study was to test the performances of a loop-mediated isothermal amplification (LAMP)-based method for the detection of Listeria monocytogenes, with particular focus on the dairy products. The specificity of the method was evaluated on 42 different Listeria spp. strains from collections, food and environmental samples. 100% (32 of 32) of the L. monocytogenes strains wer...

The YtlI regulator of Bacillus subtilis activates the transcription of the ytmI operon encoding an l-cystine ABC transporter, a riboflavin kinase, and proteins of unknown function. The expression of the ytlI gene and the ytmI operon was high with methionine and reduced with sulfate. Using deletions and site-directed mutagenesis, a cis-acting DNA sequence important for YtlI-dependent regulation ...

The detection of Listeria monocytogenes from food is currently carried out using a double enrichment. For the ISO methodology, this double enrichment is performed using half-Fraser and Fraser broths, in which the overgrowth of L. innocua can occur in samples where both species are present. In this study, we analyzed the induction of phages and phage tails of Listeria spp. in these media and in ...

Queso fresco (QF) is a handmade cheese consumed and produced in Latin America. In Mexico, QF production is associated with a microbiological risk. The aim of the study was to determine the incidence and characterization of Listeria monocytogenes, Salmonella spp., and Shiga toxin-producing Escherichia coli (STEC) in QF from retail markets of the north-western State of Sinaloa, Mexico, and to ass...

INTRODUCTION Raw-milk cheese has been identified in risk assessment as a food of greater concern to public health due to listeriosis. OBJECTIVE To determine the prevalence and levels of Listeria monocytogenes in semi-hard Idiazabal cheese manufactured by different producers in the Basque Country at consumer level. METHODOLOGY A total of 51 Idiazabal cheese samples were obtained from 10 sepa...

Contamination in pigs and pig carcasses by Listeria monocytogenes and Salmonella spp. in an industrial abattoir was co-related with animal origin and their hide status. Animals supplied by farms joining to an integrated quality control program or other pig fatteners were kept in lairage for the night and showered or were slaughtered within few hours. Prevalence in Salmonella was similar in anim...