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In this study, the antimicrobial resistance profiles of bacterial strains obtained from wild avian species recovered in wetlands of Northern Italy were described. Cloacal swabs collected from 67 aquatic birds, hunted or found dead in two private hunting grounds, were submitted to microbiological investigations and antimicrobial susceptibility testing using the Vitek 2 system, while specific PCR protocols were applied to screen for genes associated with the resistance. One hundred fifty-seven bacterial strains were characterized. The most frequent isolates were Enterococcus faecalis (36/157; 22.9%) and Escherichia coli (23/157; 14.6%). Seventy-seven isolates (77/157; 49%) were resulted resistant to at least one antibiotic, and eight isolates (8/157; 5%) were classified as multidrug resistant bacteria. Resistance for critically important antibiotics (linezolid, vancomycin, carbapenems, third-generation cephalosporins, and fluoroquinolones) was also described. Salmonella spp. was obtained from a Eurasian teal (Anas crecca), and it was subsequently analyzed by whole genome sequencing, revealing the serovar Salmonella Braenderup ST22. The phylogenetic analysis, performed with all ST22 described in 2021 and 2022, placed the strain under study in a large clade associated with human salmonellosis cases. These results suggest that migratory aquatic birds may be considered as relevant carriers of critically important antibiotic resistant bacteria and zoonotic food-borne pathogens potentially able to impact public health. [ABSTRACT FROM AUTHOR]

The Apennine wolf (Canis lupus italicus) is a subspecies of gray wolf that is widespread throughout Italy. Due to hunting and habitat loss, their population declined dramatically in the late 19th and early 20th centuries, but conservation efforts improved to restore the species to an estimated population of 3300 individuals. The presence of antibiotic-resistant bacteria in Apennine Wolf may pose a risk to its health and survival, as well as the health of other animals in its environment. In this study, we investigated the antibiotic resistance profiles of bacteria collected from Apennine wolves admitted to the Wildlife Research Center of Maiella National Park (Italy) in 2022. A total of 12 bacteria collected from four wolves were isolated and tested for susceptibility to antibiotics used in veterinary medicine and to critically important antibiotics for human health by means of the Vitek 2 system. All isolates were resistant to at least one antibiotic, and six bacteria were multidrug resistant to critically important antibiotics (third-generation cephalosporins, carbapenems and fluoroquinolones). The results of this pilot study have allowed for the characterization of resistant profiles in Escherichia coli, Enterococcus faecalis and other bacterial species not previously reported in Apennine wolves. Our findings provide important insights into antibiotic resistance in wildlife and its potential implications for the conservation of biodiversity and public health. [ABSTRACT FROM AUTHOR]

Simple Summary: Antibiotic resistance is a global problem that involves humans, animals and the environment. To counter this threat, a multidisciplinary strategy that addresses human, animal, and environmental health is needed. This approach, called One Health, was applied in this study involving wild and domestic species living in the Maiella national park (Italy). Feces and water samples from the same areas were collected to identify gram-positive and gram-negative bacteria and to define their susceptibility to several antibiotics. The results of this study showed several bacterial species with interesting resistance profiles, and in some cases, resistance against antibiotics that are critically important for human medicine. The sharing of environments between wild and domestic animals was confirmed as a key factor in antibiotic resistance dissemination at the human–animal–environment interface. Antimicrobial resistance (AMR) is a global health concern that has been linked to humans, animals, and the environment. The One Health approach highlights the connection between humans, animals, and the environment and suggests that a multidisciplinary approached be used in studies investigating AMR. The present study was carried out to identify and characterize the antimicrobial resistance profiles of bacteria isolated from wildlife and livestock feces as well as from surface water samples in Maiella National Park, Italy. Ecological and georeferenced data were used to select two sampling locations, one where wildlife was caught within livestock grazing areas (sympatric group) and one where wildlife was caught outside of livestock grazing areas (non-sympatric group). Ninety-nine bacterial isolates from 132 feces samples and seven isolates from five water samples were collected between October and December 2019. The specimens were examined for species identification, antibiotic susceptibility and molecular detection of antibiotic resistance. Forty isolates were identified as Escherichia coli, forty-eight as Enterococcus spp., eight as Streptococcus spp. and ten as other gram-negative bacteria. Phenotypic antibiotic resistance to at least one antimicrobial agent, including some antibiotics that play a critical role in human medicine, was detected in 36/106 (33.9%, 95% CI: 25–43) isolates and multidrug resistance was detected in 9/106 isolates (8.49%, 95% CI: 3.9–15.5). In addition, genes associated with antibiotic resistance were identified in 61/106 (57.55%, 95% CI: 47.5–67) isolates. The samples from sympatric areas were 2.11 (95% CI: 1.2–3.5) times more likely to contain resistant bacterial isolates than the samples from non-sympatric areas. These data suggest that drug resistant bacteria may be transmitted in areas where wildlife and livestock cohabitate. This emphasizes the need for further investigations focusing on the interactions between humans, wildlife, and the environment, the results of which can aid in the early detection of emerging AMR profiles and possible transmission routes. [ABSTRACT FROM AUTHOR]

The available data on antimicrobial resistance in pets are limited compared to those collected for food-producing animals. Bacterial urinary tract infections are some of the most important indications for antimicrobial use in pets, and empiric antimicrobial treatments are often administered in the presence of clinical signs. In this study, the results obtained from the laboratory investigations carried out on dogs and cats with urinary tract infections coming from veterinary clinics and practices in Central Italy were evaluated to provide additional data concerning the bacterial urinary pathogens and their antimicrobial resistance patterns in pets. A total of 635 isolates were collected from urine samples. Escherichia coli was the most common species recovered in dogs and cats, followed by Proteus mirabilis and Enterococcus spp. Furthermore, it was possible to isolate bacteria not usually described in other studies concerning pets such as Pantoea dispersa, Raoultella ornithinolytica, and Pasteurella pneumotropica (also known as Rodentibacter pneumotropicus). Based on the antimicrobial susceptibility results, 472/635 (74.3%) isolates were resistant to at least one antibiotic and 285/635 (44.8%) isolates were classified as multidrug-resistant. Monitoring the antibiotic resistance profiles in pet infections is important not only for the public health implications, but also to collect data useful for the treatment of diseases in pets. [ABSTRACT FROM AUTHOR]

Simple Summary: Antibiotic resistance represents an emergent threat for animals, humans, and the environment. Food-producing animals are directly involved in the dissemination and maintenance of resistant bacteria and their genetic determinants. The genes responsible for resistance mechanisms in bacteria can be located at the chromosomal level or in extra-chromosomal mobile genes, and are transferrable to other bacteria by different modalities. The use of antibiotics in livestock can exercise a selective pressure on resistance determinants and their persistence in intestinal microbiota. In this respect, poultry farming represents a potential driver of resistance genes as these genes can reach the environment or the food chain from poultry litter. In this study, litter samples from conventional flocks (where antibiotics are allowed only for therapeutic purposes) and antibiotic-free farms (where these molecules are excluded) are screened for some resistance genes against antibiotics routinely used in veterinary practice (tetracyclines, aminoglycosides, lincomycin), along with some critically/highly important antibiotics exclusively intended for humans (chloramphenicol, colistin, vancomycin, carbapenems). The results showed the presence of several resistance genes in poultry litter from both farming systems. Interestingly, the highest positivity was observed for tetracycline genes in antibiotic-free flocks, raising some concerns about the role of alternative farming systems in the reduction in antibiotic resistance in food-producing animals. Antimicrobial resistance is a complex and widespread problem threatening human and animal health. In poultry farms, a wide distribution of resistant bacteria and their relative genes is described worldwide, including in Italy. In this paper, a comparison of resistance gene distribution in litter samples, recovered from four conventional and four antibiotic-free broiler flocks, was performed to highlight any influence of farming systems on the spreading and maintenance of resistance determinants. Conventional PCR tests, targeting the resistance genes related to the most used antibiotics in poultry farming, along with some critically important antibiotics for human medicine, were applied. In conventional farms, n. 10 out of n. 30 investigated genes were present in at least one sample, the most abundant fragments being the tet genes specific for tetracyclines, followed by those for aminoglycosides and chloramphenicol. All conventional samples resulted negative for colistin, carbapenems, and vancomycin resistance genes. A similar trend was observed for antibiotic-free herds, with n. 13 out of n. 30 amplified genes, while a positivity for the mcr-1 gene, specific for colistin, was observed in one antibiotic-free flock. The statistical analysis revealed a significant difference for the tetM gene, which was found more frequently in the antibiotic-free category. The analysis carried out in this study allowed us to obtain new data about the distribution of resistance patterns in the poultry industry in relation to farming types. The PCR test is a quick and non-expensive laboratory tool for the environmental monitoring of resistance determinants identifying potential indicators of AMR dissemination. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the resistance patterns against selected critically and highly important antibiotics (quinupristin/dalfopristin, vancomycin, and linezolid) in 48 Enterococcus isolates obtained from wild (red deer and Apennine chamois) and domestic (cattle, sheep, and goats) ruminants living with varying degrees of sympatry in the protected area of Maiella National Park (central Italy). According to CLSI breakpoints, 9 out of 48 isolates (18.8%) showed resistance to at least one antibiotic. One Apennine chamois isolate was resistant to all tested antibiotics. The PCR screening of related resistance genes highlighted the occurrence of msrC or cfrD in seven Enterococcus resistant isolates. In addition, msrC and vanC genes were amplified in susceptible isolates. Specific sequences of virulence genes (gelE, ace, efa, asa1, and esp) related to pathogenic enterococci in humans were amplified in 21/48 isolates (43.75%), belonging mostly to wild animals (15/21; 71.42%). This is the first report of linezolid-resistant enterococci harboring virulence genes in Italian wildlife with special regard to the red deer and Apennine chamois species. The results allow us to evaluate the potential role of wild animals as indicators of antibiotic resistance in environments with different levels of anthropic pressure. [ABSTRACT FROM AUTHOR]