The objectives of this study were to ascertain the fecal ESBL/AmpC-E. coli prevalence and to detect risk factors for their occurrence in young pre-weaned calves and their dams on large dairy farms in Germany. From 2018–2019 we investigated 2816 individual fecal samples from pre-weaned dairy calves and their dams, representing seventy-two farms (mean = 667 milking cows) from eight German federal states. To assess possible risk factors associated with ESBL/AmpC-E. coli prevalence in calves and dams, a questionnaire was performed, collecting management data. We observed an ESBL/AmpC-E. coli prevalence of 63.5% (95% CI: 57.4–69.5) among the sampled calves and 18.0% (95% CI: 12.5–23.5) among the dams. On all farms, at least one positive sample was obtained. To date, this is the highest ESBL/AmpC-E. coli prevalence observed in dairy herds in Europe. Feeding with waste milk was identified as a significant risk factor for a high prevalence of ESBL/AmpC-E. coli in calves. Many calves at large dairies in Germany are fed with waste milk due to the large amounts generated as a result of antibiotic dry-off routines and mastitis treatment with antibiotics. Other notable risk factors for high ESBL/AmpC-E. coli in calves were the general fitness/health of dams and calves, and the quality of farm hygiene. Taken together, these findings suggest that new or improved approaches to animal health management, for example, antibiotic dry cow management (selective dry cow therapy) and mastitis treatment (high self-recovery), as well as farm hygiene, should be researched and implemented.

Antimicrobial resistance (AMR) is a serious global health threat and extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales are a major contributor. This study aimed to gain a deeper insight into the AMR burden of wild animals. In total, 1595 fecal samples were collected by two systematic searches in Mecklenburg-Western Pomerania, north-east Germany. Samples were screened for ESBL-carrying Escherichia (E.) coli and isolates found were further analyzed using antimicrobial susceptibility testing and whole-genome sequencing. We found an estimated prevalence of 1.2% ESBL-producing E. coli in wild boar and 1.1% in wild ruminants. CTX-M-1 was the most abundant CTX-M type. We also examined fecal samples from wild boar and wild ruminants using shotgun metagenomics to gain insight into the resistome in wild animals. The latter revealed significantly lower normalized counts for AMR genes in wildlife samples compared to farm animals. The AMR gene levels were lower in wild ruminants than in wild boar. In conclusion, our study revealed a low prevalence of ESBL-producing E. coli and a low overall AMR gene burden in wild boar and wild ruminants, probably due to the secluded location of the search area.

Antimicrobial resistance (AMR) is a serious global health threat with extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales as the most critical ones. Studies on AMR in wild birds imply a possible dissemination function and indicate their potential role as sentinel animals. This study aimed to gain a deeper insight into the AMR burden of wild waterfowl by sampling semi-wild mallard ducks used as sentinels and to identify if AMR bacteria could be recommended to be added to the pathogens of public health risks to be screened for. In total, 376 cloacal and pooled fecal samples were collected from the sentinel plant over a period of two years. Samples were screened for ESBL-carrying E. coli and isolates found further analyzed using antimicrobial susceptibility testing and whole-genome sequencing. Over the sampling period, 4.26% (16/376) of the samples were positive for ESBL-producing E. coli. BlaCTX-M-1 and blaCTX-M-32 were the most abundant CTX-M types. Although none of the top global sequence types (ST) could be detected, poultry-derived ST115 and non-poultry-related STs were found and could be followed over time. The current study revealed low cases of ESBL-producing E. coli in semi-wild mallard ducks, which proves the suitability of sentinel surveillance for AMR detection in water-associated wildlife.

Yersinia (Y.) pseudotuberculosis is an important pathogen for both humans and animals. It can infect livestock as well as pets and wild animals. During the last years, a number of reports describe the isolation of Y. pseudotuberculosis from zoo animals, mainly birds and mammals, for which the infection was mostly lethal. Between 2005 and 2019, there were at least 17 cases of deceased mammals belonging to five different species at the Zoo Wuppertal, Germany, which suffered from a Y. pseudotuberculosis infection. Since only scarce information exists on properties of Y. pseudotuberculosis from zoo animals, we characterized eight isolates, covering all infected species, in detail. All of them are members of biotype 1, but belong to five serotypes, five sequence types (STs) and even seven cgMLST types. Using Pulsed-Field Gel Electrophoresis (PFGE) analysis and whole-genome sequencing (WGS), seven isolates could be discriminated from each other. They differ significantly regarding their virulence genes and mobile genetic elements. While the virulence plasmid pYV existed in all serotypes (five isolates), a complete high pathogenicity island (HPI) was detected only in the serotypes O:1a, O:1b and O:13 (four isolates), but not in O:2a and O:2b. Similarly, the content of other plasmids and prophages varies greatly between the isolates. The data demonstrates that the deceased mammals were infected by seven individual isolates and not by a single type predominating in the zoo animals.

This study investigated the presence of extended-spectrum beta-lactamase-producing Enterobacterales in selected surface waters in the Ashanti Region in Ghana. Subsequent genomic analysis revealed that one-fifth of the isolates were genotypically carbapenem-resistant. Phenotypic susceptibility testing not only confirmed their carbapenem resistance, but also uncovered two cefiderocol-resistant isolates.