Genome sequence, antibiotic resistance genes, and plasmids in a monophasic variant of Salmonella typhimurium isolated from retail pork.

A Salmonella isolate from retail pork was whole genome sequenced using Illumina NovaSeq6000, with a 5,320,119 bp genome and 51.06% GC content. Several antibiotic resistance genes and plasmids, including blaTEM-1, aac(6')-IIc, IncHI2, and p0111 were obtained from subsequent analysis. These findings provide vital insights into generic determinants of antimicrobial resistance (AMR) in this foodborne pathogen.

Emergence of Extended-Spectrum Cephalosporin- and Colistin-Resistant Enterobacterales in Otherwise Healthy University Students.

Resistance to last resort antibiotics has been increasing, particularly in low- and middle-income countries such as Lebanon, which has well established challenges in antimicrobial stewardship and other public health and environmental issues. However, data on the emergence of antibiotic resistance in the community in Lebanon are limited. In this study, we assessed resistance to last resort antibiotics in the fecal samples of 111 otherwise healthy university students in north Lebanon. The results showed that 47.7% of the samples harbored extended-spectrum cephalosporin-resistant isolates, while 2.7% of the samples yielded colistin-resistant isolates. Furthermore, molecular analyses showed that the ß-lactamase gene group, blaCTX-M-1 group, was detected in the majority (93%) of screened extended-spectrum ß-lactamase isolates. In addition, the colistin-resistant Escherichia coli isolates carried mcr-1, including the novel mcr-1.26 variant, which was previously reported in clinical samples as well as in domesticated animals and the environment in Lebanon. Taken together, these findings highlight the occurrence of resistance to important antibiotics in the community, perhaps suggesting diffuse sources, including clinical and environmental settings, and multiple factors driving the spread of multidrug-resistant bacteria and resistance determinants. There is a pressing need for comprehensive antimicrobial stewardship programs and the implementation of evidence-based practices in clinical and community settings to mitigate the increasing spread of antimicrobial resistance.

Effect of Food Matrix and Treatment Time on the Effectiveness of Grape Seed Extract as an Antilisterial Treatment in Fresh Produce.

Listeriosis outbreaks were associated with contaminated fruits and vegetables, including cantaloupe, apples, and celery. Grape seed extract (GSE) is a natural antimicrobial with potential for reducing Listeria monocytogenes contamination in food. This study assessed the effectiveness of GSE to reduce L. monocytogenes on fresh produce and the impact of food matrices on its antilisterial activity. GSE showed MIC values of 30-35 µg/mL against four Listeria strains used in this study. A total of 100 g portions of cantaloupe, apples, and celery were inoculated with L. monocytogenes and treated with 100-1000 µg/mL of GSE for 5 or 15 min. Results were analyzed using Rstudio and a Tukey's test. Treated produce had significantly lower L. monocytogenes counts than the control samples (p-value < 0.05). The inhibition was significantly higher on apples and lowest on cantaloupe. Moreover, a 15 min treatment was found to be more effective than a 5 min treatment in reducing L. monocytogenes on all produce types. The reduction in L. monocytogenes levels varied between 0.61 and 2.5 log10 CFU reduction, depending on the treatment concentration, duration, and produce matrix. These findings suggest that GSE is an effective antilisterial treatment for fresh produce, with varying levels of effectiveness depending on the food matrix and treatment time.