Whole-genome sequence analysis of Shiga toxin-producing Escherichia coli O157 strains isolated from wild deer and boar in Japan

Antimicrobial resistance in wild game mammals: a glimpse into the contamination of wild habitats in a systematic review and meta-analysis

BACKGROUND

Wild game meat has over the years gained popularity across the globe as it is considered a food source with high protein content, low fat content, and a balanced composition of fatty acids and minerals, which are requirements for a healthy diet. Despite this popularity, there is a concern over its safety as many species of wildlife are reservoirs of zoonotic diseases including those of bacterial origin, more so antibiotic-resistant bacteria.

METHODS

This study aimed to describe the prevalence of antibiotic-resistant bacteria in mammalian wild game, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

The overall pooled prevalence of antibiotic resistance was established at 59.8% while the prevalence of multidrug resistance (MDR) was 17.2%. Resistance was reported in 32 wild game species and the meta-analysis revealed the highest prevalence of antibiotic resistance in Yersinia spp. (95.5%; CI: 76.8 - 100%) followed by Enterococcus spp. (71%; CI: 44.1 - 92%), Salmonella spp. (69.9%; CI: 44.3 - 90.0%), Staphylococcus spp. (69.3%; CI: 40.3 - 92.3%), and Escherichia coli (39.5%; CI: 23.9 - 56.4%). Most notably, resistance to highest priority, critically important antimicrobials, was recorded in all genera of bacteria studied. Additionally, a significantly higher prevalence of antibiotic resistance was observed in studies conducted in remote settings than those in the vicinity of anthropogenic activities, pointing to extensive contamination of wild habitats.

CONCLUSION

This review shows the presence of antibiotic resistance and the carriage of antimicrobial resistance (AMR) genes by bacteria isolated from mammalian wild game species. This is a cause for concern if critical steps to prevent transmission to humans from meat and meat products are not applied in the wild game meat production chain. The extensive occurrence of antibiotic resistance in the wild calls for expansion and adaptation of future AMR surveillance plans to include areas with various anthropogenic pressures including in sylvatic habitats.

Within-host genetic diversity of extended-spectrum beta-lactamase-producing Enterobacterales in long-term colonized patients

Despite recognition of the immediate impact of infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-PE) on human health, essential aspects of their molecular epidemiology remain under-investigated. This includes knowledge on the potential of a particular strain to persist in a host, mutational events during colonization, and the genetic diversity in individual patients over time. To investigate long-term genetic diversity of colonizing and infecting ESBL-Klebsiella pneumoniae species complex and ESBL-Escherichia coli in individual patients over time, we performed a ten-year longitudinal retrospective study and extracted clinical and microbiological data from electronic health records. In this investigation, 76 ESBL-K. pneumoniae species complex and 284 ESBL-E. coli isolates were recovered from 19 and 61 patients. Strain persistence was detected in all patients colonized with ESBL-K. pneumoniae species complex, and 83.6% of patients colonized with ESBL-E. coli. We frequently observed isolates of the same strain recovered from different body sites associated with either colonization or infection. Antimicrobial resistance genes, plasmid replicons, and whole ESBL-plasmids were shared between isolates regardless of chromosomal relatedness. Our study suggests that patients colonized with ESBL-producers may act as durable reservoirs for ongoing transmission of ESBLs, and that they are at prolonged risk of recurrent infection with colonizing strains.

Presence of Foodborne Bacteria in Wild Boar and Wild Boar Meat-A Literature Survey for the Period 2012-2022

The wild boar is an abundant game species with high reproduction rates. The management of the wild boar population by hunting contributes to the meat supply and can help to avoid a spillover of transmissible animal diseases to domestic pigs, thus compromising food security. By the same token, wild boar can carry foodborne zoonotic pathogens, impacting food safety. We reviewed literature from 2012-2022 on biological hazards, which are considered in European Union legislation and in international standards on animal health. We identified 15 viral, 10 bacterial, and 5 parasitic agents and selected those nine bacteria that are zoonotic and can be transmitted to humans via food. The prevalence of Campylobacter, Listeria monocytogenes, Salmonella, Shiga toxin-producing E. coli, and Yersinia enterocolitica on muscle surfaces or in muscle tissues of wild boar varied from 0 to ca. 70%. One experimental study reported the transmission and survival of Mycobacterium on wild boar meat. Brucella, Coxiella burnetii, Listeria monocytogenes, and Mycobacteria have been isolated from the liver and spleen. For Brucella, studies stressed the occupational exposure risk, but no indication of meat-borne transmission was evident. Furthermore, the transmission of C. burnetii is most likely via vectors (i.e., ticks). In the absence of more detailed data for the European Union, it is advisable to focus on the efficacy of current game meat inspection and food safety management systems.

Whole Genome Sequencing and CRISPR/Cas9 Gene Editing of Enterotoxigenic Escherichia coli BE311 for Fluorescence Labeling and Enterotoxin Analyses

Some prevention strategies, including vaccines and antibiotic alternatives, have been developed to reduce enterotoxigenic Escherichia coli proliferation in animal production. In this study, a wild-type strain of BE311 with a virulent heat-stable enterotoxin gene identical to E. coli K99 was isolated for its high potential for gene expression ability. The whole genome of E. coli BE311 was sequenced for gene analyses and editing. Subsequently, the fluorescent gene mCherry was successfully knocked into the genome of E. coli BE311 by CRISPR/Cas9. The E. coli BE311−mCherry strain was precisely quantified through the fluorescence intensity and red colony counting. The inflammatory factors in different intestinal tissues all increased significantly after an E. coli BE311−mCherry challenge in Sprague−Dawley rats (p < 0.05). The heat-stable enterotoxin gene of E. coli BE311 was knocked out, and an attenuated vaccine host E. coli BE311-STKO was constructed. Flow cytometry showed apoptotic cell numbers were lower following a challenge of IPEC-J2 cells with E. coli BE311-STKO than with E. coli BE311. Therefore, the E. coli BE311−mCherry and E. coli BE311-STKO strains that were successfully constructed based on the gene knock-in and knock-out technology could be used as ideal candidates in ETEC challenge models and for the development of attenuated vaccines.