Among the seven species of Entamoeba known to infect humans, E. histolytica is widely recognized as a pathogen. It is reported that Entamoeba infections are common in the developing world, but rare in developed countries. The best way to diagnose these protozoan parasites is to detect antigens or DNA in the stool. This study aimed to review the prevalence, distribution, and diagnosis methods of Entamoeba spp. infecting humans in the Americas between 1990 and 2022. A systematic review and meta-analysis were performed, including 227 studies on Entamoeba infections from 30 out of 35 American countries. The pooled prevalence of each species of Entamoeba was calculated using the random-effects model. The assignment of Entamoeba species was mainly performed by microscopy. The most widely distributed and prevalent species was E. coli (21.0%). Of the studies, 49% could not differentiate the species of the Entamoeba complex. The pathogenic species E. histolytica was distributed among 22 out of 30 American countries studied, with a pooled prevalence of 9%. Molecular data on Entamoeba species are still scarce. This is the first study that reviewed and summarized data on the prevalence of this protozoan genera among American countries.

Between June and September 2023, a total of 80 meat samples from pork and chicken meat were collected from 16 retail markets in La Plata, Argentina. Eighty-four highest priority critically important antimicrobial-resistant Escherichia coli and two Salmonella spp. were isolated. Resistance to ciprofloxacin and cefotaxime was observed in 65 and 49 E. coli isolates, respectively. Seventy-five E. coli isolates were multidrug resistant. Fourteen E. coli isolates from chicken meat showed resistance to three of the HPCIA. Resistance to third-generation cephalosporin was associated with bla_CTX-M. It is 15 times more likely to find HPCIA-resistant E. coli in chicken meat than in pork.

The occurrence of Escherichia coli resistant to high-priority critically important antimicrobials (HPCIA) in the food chain is a growing concern for food safety and public health. This study aimed to evaluate whether HPCIA-resistant E. coli isolated from pork and chicken meat at retail markets in La Plata, Buenos Aires, Argentina, exhibit source-associated genomic differentiation through whole-genome sequencing. The isolates displayed a polyclonal population structure, encompassing multiple phylogenetic groups and sequence types. Virulence gene profiles were highly diverse, with chicken-derived isolates harbouring a substantially higher number of virulence genes than pork isolates. Notably, one pork isolate carried a complete set of virulence genes characteristic of diarrheagenic E. coli. Single Nucleotide Polymorphism-based phylogenetic analysis revealed several closely related subclusters, including strains recovered from both pork and chicken meat from the same retail markets, suggesting recent clonal sharing or cross-contamination at the point of sale. These findings highlight the circulation of genetically diverse HPCIA-resistant E. coli in retail meat, underscoring the potential public health risk and the importance of monitoring resistance and virulence determinants throughout the food production chain.

The occurrence of Escherichia coli resistant to high-priority critically important antimicrobials (HPCIA) in the food chain is a growing concern for food safety and public health. This study aimed to evaluate whether HPCIA-resistant E. coli isolated from pork and chicken meat at retail markets in La Plata, Buenos Aires, Argentina, exhibit source-associated genomic differentiation through whole-genome sequencing. The isolates displayed a polyclonal population structure, encompassing multiple phylogenetic groups and sequence types. Virulence gene profiles were highly diverse, with chicken-derived isolates harbouring a substantially higher number of virulence genes than pork isolates. Notably, one pork isolate carried a complete set of virulence genes characteristic of diarrheagenic E. coli. single Nucleotide Polymorphism-based phylogenetic analysis revealed several closely related subclusters, including strains recovered from both pork and chicken meat from the same retail markets, suggesting recent clonal sharing or cross-contamination at the point of sale. These findings highlight the circulation of genetically diverse HPCIA-resistant E. coli in retail meat, underscoring the potential public health risk and the importance of monitoring resistance and virulence determinants throughout the food production chain.

High-risk clones represent a major concern, as they are very efficient vehicles for mobile genetic elements carrying antimicrobial resistance genes and therefore promote their spread, especially if they confer resistance to cefotaxime, ciprofloxacin, and fosfomycin, included within the highest-priority, critically important antimicrobial agents (HPCIA). Between February 2022 and April 2024, 138 pork samples were obtained from 46 butcher shops in La Plata, Buenos Aires, Argentina. A total of 102 HPCIA-resistant E. coli were isolated. Eighty-five HPCIA-resistant E. coli were selected for whole-genome sequencing. Of these, 27 belonged to 9 clones described as high risk: ST101 (n = 5), ST10 (n = 4), ST48 (n = 4), ST744 (n = 4), ST23 (n = 3), ST58 (n = 2), ST88 (n = 2), ST117 (n = 2), and ST410 (n = 1). Twelve of them were third-generation cephalosporin-resistant. Resistance was mediated by bla_CTX-M-55 (n = 7), bla_CTX-M-14 (n = 4), bla_CTX-M-8 (n = 1), and bla_CMY-2 (n = 1). This study highlights the importance of food products and the food production chain as reservoirs of high-risk clones and resistance genes of epidemiological relevance to public health.