RESUMEN

Cantaloupes contaminated with pathogens have led to many high-profile outbreaks and illnesses. Since bacterial virulence genes (VGs) can act in tandem with antibiotic-resistance and mobile genetic elements, there is a need to evaluate these gene reservoirs in fresh produce, such as cantaloupes. The goal of this study was to assess the distribution of antibiotic-resistance, virulence, and mobile genetic elements genes (MGEGs) in cantaloupe farm environments. A total of 200 samples from cantaloupe melons (n = 99), farm workers' hands (n = 66), and production water (n = 35) were collected in México. Each sample was assayed for the presence of 14 antibiotic-resistance genes, 15 VGs, and 5 MGEGs by polymerase chain reaction. Our results indicated that tetracycline (tetA and tetB) (18% of cantaloupe, 45% of hand samples) and sulfonamide (sul1) (30% of cantaloupe, 71% of hand samples) resistance genes were frequently detected. The colistin resistance gene (mcr1) was detected in 10% of cantaloupe and 23% of farm workers' hands. Among VGs, Salmonella genes invA and spiA were the most abundant. There was a significantly higher likelihood of detecting antibiotic-resistance, virulence, and MGEGs on hands compared with water samples. These results demonstrate a diverse pool of antibiotic-resistance and VGs in cantaloupe production.

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RESUMEN

The safety and bioactive potential of crude carotenoid extract from Cantaloupe melon nanoencapsulated in porcine gelatin (EPG) were evaluated in a chronic inflammatory experimental model. Animals were fed a high glycemic index and high glycemic load (HGLI) diet for 17 weeks and treated for ten days with 1) HGLI diet, 2) standard diet, 3) HGLI diet + crude carotenoid extract (CE) (12.5 mg/kg), and 4) HGLI diet + EPG (50 mg/kg). General toxicity signals were investigated, considering body weight, food intake, hematological, biochemical parameters, relative weight, morphology, and histopathology of organs. The biochemical parameters indicated the low toxicity of EPG. Acute hepatitis was observed in animals' livers, but CE and EPG groups presented improved tissue appearance. Chronic enteritis was observed in animals, with villi and intestinal glands preservation in the EPG group. The results suggest the safety and the bioactive effect of EPG, possibly related to its anti-inflammatory potential.

RESUMEN

The increase in the consumption of fresh produce has correlated with a rise in the number of reported foodborne illnesses. To identify potential risk factors associated with postharvest practices, the present study employed multilocus sequence typing (MLST) for the genotypic classification of Escherichia coli isolates recovered from three sources sampled at seven operational stages in a cantaloupe packinghouse in Northwestern Mexico. The MLST analysis results indicated that the E. coli isolates were classified into 18 different sequence types (ST), and 11 of these STs were found to be novel. ST-171 was the predominant type and was found in 19% (7/36) of the recovered isolates. Interestingly, the novel ST-827 was found to be significantly associated with isolates recovered from workers' hands, sampled during final postwash stages. Further phylogenetic analyses to examine the relatedness of the STs revealed genetic heterogeneity. Fourteen of the identified STs were assigned to known clonal groups, while the remaining four novel STs were distinct and did not cluster with any clonal group. The present study has provided the first evidence indicating that several sources from distinct operational stages in a cantaloupe packinghouse may contribute to a genotypic and phylogenetic diverse set of E. coli isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: Packinghouses can be considered as a potential source of microbial contamination. Using multilocus sequence typing, this study identified a genotypic and phylogenetic diverse set of Escherichia coli isolates recovered from the surfaces of cantaloupes, workers' hands and processing equipment at a cantaloupe packinghouse. A total of 61% of the sequence types identified were novel, and a distinct sequence type, ST-827, was significantly associated with worker's hands, sampled during the final postwash operational stages in the packinghouse. These findings serve as a baseline to identify potential sources of microbial contamination at distinct operational stages in a cantaloupe packinghouse.

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