Prevalence of Listeria spp. and antibiotic susceptibility of Listeria monocytogenes isolated from raw chicken and ready-to-eat chicken products in Jordan

Prediction of Listeria innocua survival in fully cooked chicken breast products during postpackage thermal treatment

The effectiveness of postpackage hot water thermal treatment on survival of Listeria innocua in fully cooked chicken breast products was investigated at 60, 70, 80, and 90°C. Primary models based on log-linear and Weibull models were used to fit bacterial survival curves at different temperatures. The prediction plot and fit statistics indicated that the Weibull model provided a better fit than the log-linear model and was selected as the primary model. A secondary model based on linear regression was developed to describe the effect of temperature on the kinetic parameters of Listeria innocua survival derived from the Weibull model. The root mean square error and coefficients of determination indicated a good fit of the secondary model. The models were validated by independent data from pilot plant tests, and the values of bias factor and accuracy factor fell into the acceptable range. The models developed in this study can assist poultry producers and risk managers in designing appropriate thermal treatment regimens to minimize the risk associated with Listeria in ready-to-eat poultry products.

Management of microbial food safety in Arab countries

Microbial food safety remains a major economic and public health concern in Arab countries. Over the past several years, many of these countries have attempted to revise and upgrade food quality control and surveillance programs; however, these systems vary in scope and effectiveness. This review addresses the major reported foodborne outbreaks and multidrug resistance of pathogenic microorganisms isolated from food products. Major foodborne pathogens of concern included Brucella spp., Clostridium botulinum, fecal coliforms, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and Staphylococcus aureus. Measures for managing microbial food hazards based on a comprehensive risk analysis also are proposed.

Current status of antibiograms of Listeria ivanovii and Enterobacter cloacae isolated from ready-to-eat foods in Alice, South Africa

This study assessed the antimicrobial susceptibility of 51 Listeria ivanovii and 33 Enterobacter cloacae strains isolated from various ready-to-eat foods sold in Alice, South Africa. Isolates were identified using standard microbiological tests and further confirmed using API 20E and API Listeria kits. The disc diffusion technique was used to screen for antimicrobial susceptibility against 15 antimicrobials; minimum inhibitory concentration of five antibiotics was determined by the broth dilution method. All the strains of E. cloacae (100%) and 96% of L. ivanovii isolates were resistant to at least four or more of the antibiotics; nineteen antibiotypes were obtained based on the antibiotics used in the study. Antibiotype A5: A^R PG^R VA^R E^R AP^R was predominant in both L. ivanovii (23.5%) and E. cloacae (57.5%) isolates. Marked susceptibility of Listeriaivanovii was observed against chloramphenicol, ciprofloxacin, streptomycin and trimethoprim/sulfamethoxazole (100%) each while E. cloacae registered 100% susceptibility to ciprofloxacin only. Various percentages of susceptibility was reported to chloramphenicol and gentamicin (91%) each, nalidixic acid (97%) and streptomycin (94%). The MIC₉₀ ranged from 0.004–7.5 µg/mL with E. cloacae being the most susceptible organism. The study demonstrated the presence of multi-resistant strains of bacteria in ready-to-eat-foods and speculates that these foods could serve as important vehicles transmitting multi-resistant bacteria to humans.