The occurrence of antimicrobial resistance in commensal strains of Escherichia coli and Staphylococcus spp. was investigated in 320 samples collected from patients and the environment of a veterinary university hospital—specifically, the consultation area (CA) and intensive care unit (ICU). E. coli was isolated in 70/160 samples (44%), while Staphylococcus spp. were isolated in 110/160 (69%) samples. The occurrence of multidrug-resistant (MDR) isolates from CA and ICU admission were similar for E. coli (1/12 (8%) versus 4/27 (15%), respectively) and Staphylococcus spp. (10/19 (53%) versus 26/50 (52%), respectively). MDR E. coli isolates increased significantly at hospital discharge (18/31; 58%; p = 0.008). Antimicrobial treatment administered during hospitalization was a risk factor for carriage of MDR E. coli (OR, 23.9; 95% CI: 1.18–484.19; p = 0.04) and MDR Staphylococcus spp. (OR, 19.5; 95% CI 1.30–292.76; p = 0.02), respectively. The odds ratio for MDR E. coli was 41.4 (95% CI 2.13–806.03; p = 0.01), if the administration of fluoroquinolones was evaluated. The mecA gene was detected in 19/24 (79%) coagulase-positive Staphylococcus spp. isolates resistant to oxacillin. High rates of MDR Staphylococcus spp. were reported. Hospitalization in the ICU and antimicrobial treatment were risk factors for colonization by MDR commensal bacteria.

The role of companion animals in the spread of antimicrobial resistance (AMR) is still not well known. As part of a wider surveillance system, this study aimed to provide data about AMR in bacterial isolates from infections in companion animals referred to an Italian University Veterinary Hospital (VUH) from November 2020 to September 2022. A total of 940 isolates were identified with MALDI-TOF MS and subsequently the antimicrobial susceptibility test (AST) for 12 antimicrobials was performed. Urine was the most commonly submitted specimen (54.92%) and Escherichia coli was the most common bacterial species isolated (36.06%). Out of the 940 isolates, 747 (79.47%) were nonsusceptible to at least one drug (AMR), while 420 (44.68%) were considered multidrug resistant (MDR). The highest nonsusceptibility percentages were recorded for clindamycin (59.65 %), erythromycin (58.96 %), ampicillin (52.85%), and enrofloxacin (48.19%). Alarming percentages were recorded also for ceftiofur (25.51%), amoxicillin–clavulanate (22.99%), and piperacillin–tazobactam (15.85%). In multivariable risk factors analysis, previous use of invasive devices ( in both cases) and previous use of antimicrobials ( in both cases) were statistically related with higher AMR and MDR percentages. Apart from a general evaluation, the study focused on specific bacterial species (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and specimens (blood cultures, urine from suspected healthcare-associated urinary tract infections, and surgical site infections), showing in both cases higher AMR and MDR percentages compared to average. These data highlight the urgency to further investigate AMR spread in pets and how passive surveillance systems can be effective tools to monitor AMR and to optimize antimicrobial use.

The phenomenon of antibiotic resistance stands as a paramount health challenge in the contemporary era. Within a One Health approach, it becomes crucial to effectively track the dissemination of antibiotic resistance, not only within humans and animals but also within the environment. To investigate the environment, the honey bee (Apis mellifera) has emerged as a prominent environmental bioindicator due to its social, behavioral, and morphological features. The objective of this study was to describe the antimicrobial resistance (AMR) patterns of bacterial isolates from the body surface and the gut of honey bees sampled from 33 colonies throughout the Emilia-Romagna region (Italy). A total of 608 strains were examined for 19 distinct antimicrobial compounds from various classes, and the results showed that more than 50% of the isolates for eight out of nine provinces showed characteristics of nonsusceptibility toward amoxicillin and penicillin, and, generally, 98.19% of isolated strains were considered AMR and 74.67% exhibited multidrug resistance (MDR) characteristics, more frequent in Gram-negative strains (87.74%) than in Gram-positive ones (60.34%). Additionally, a significant correlation with a lower prevalence of MDR bacteria was demonstrated for one province (Ferrara, odds ratio (OR) = 3.33, (1.67; 6.64), $p=0.0006$ ). In conclusion, this study provides evidence for the utility of A. mellifera colonies as bioindicators for MDR bacteria, enabling their characterization and distribution at a geographical level. Additional investigations are required to further explore the potential role of honey bees as bioindicators for antimicrobial-resistant bacteria, particularly in terms of their association with environmental characteristics.

Carbapenems are considered one of the most important last‐resort classes of antibiotics, and the spread of carbapenem‐resistant Enterobacterales (CRE) is a serious concern worldwide. From a One Health point of view, reports on CRE in companion animals are increasing, requiring attention regarding their role in maintenance and direct transmission to humans. The aim of this study was to assess the frequency of detection at admission and the in‐hospital acquisition of CRE from perirectal swabs in dogs and cats hospitalized in an Italian Veterinary Teaching Hospital (VTH). Of the 150 patients sampled, 11.3% ( n = 17) were CRE carriers at admission, 25.6% ( n = 34) acquired CRE in their commensal microbiota during their hospital stay, and 2% ( n = 3) developed an infection caused by CRE. Genotypical analysis showed that in 100% (78/78) of the CRE isolates (44 Escherichia coli , 33 Klebsiella pneumoniae , and 1 Klebsiella aerogenes ) carbapenem resistance was conferred by the carbapenemase gene bla _NDM , suggesting an endemic presence of such gene within the hospital. Co‐occurrent β ‐lactamase‐encoding genes were found in most of the isolates. Risk factors associated with CRE acquisition were length of hospitalization ( p = 0.0002) and treatment with piperacillin–tazobactam (PTZ; p = 0.0380), indicating potential cross‐selection of CRE. These results reinforce the suspicion that companion animals could silently contribute to the maintenance and dissemination of CRE in the local community, posing a threat to global health.

Bacterial urinary tract infections (UTIs) are common in small animal practice and their inappropriate treatment contributes to the antimicrobial resistance (AMR) spreading. This study assessed bacterial prevalence, non-susceptibility percentages, antimicrobial prescription and the impact of the application of international guidelines redacted by the International Society for Companion Animals Infectious Disease (ISCAID) in dogs and cats with UTIs evaluated at a European veterinary university hospital, over a 30-month period. A total of 729 bacterial isolates were included. The most frequently isolated bacterial species was Escherichia coli in both dogs (52.8%) and cats (45.7%). Following ISCAID guidelines, almost half of the cases were classified as upper UTIs (24.9%) or recurrent cystitis (24.8%). Multidrug resistance (MDR) percentage was 37.3% (n = 272). Over five semesters, MDR significantly decreased (p = 0.001). Additionally, a significant decrease was recorded for specimens from patients previously treated (p = 0.018) and under treatment at sampling (p < 0.001). Previous treatment with amoxicillin-clavulanate (p = 0.001), marbofloxacin (p < 0.001), enrofloxacin (p < 0.001) and piperacillin-tazobactam (p = 0.016) was linked with higher MDR rates. This study highlighted that companion animals are potential reservoirs for AMR; moreover, international guidelines applied in the daily practice guiding antimicrobial stewardship can lead to a reduction in AMR over time.

Paratuberculosis is considered one of the most economically devastating infectious diseases of domestic livestock, and the most effective control strategy is a combination of 'test-and-cull' and on-farm biosecurity measures. In Italy, a Voluntary National Control Plan (VNCP) and guidelines have been introduced to reduce the impact of the disease, and farmers can voluntarily enroll in the control plan. The main aims of this study were: i) the description of the trend over a 4-year period on total, within-herd (WH) and between herd (BH) apparent seroprevalences observed in 64 dairy herds members of a mutual company located in Italy after the introduction of a proposed "Customized Control Plan" (CCP); ii) the evaluation of its effectiveness in terms of percentage of participating farms that decided to join the VNCP. Analyses on serum samples were performed with Enzyme-Linked Immuno Sorbent Assay (ELISA) method and revealed a general decrease in both total, WH and BH apparent seroprevalence. Total average apparent seroprevalence decreased from 2.39% in 2017 to 1% in 2020. Negative herds raised from 51.9% in 2017 to 71.1% in 2020, while farms with WH apparent seroprevalence > 5% decreased from 17.3% in 2017 to 4.4% in 2020. BH apparent seroprevalence decreased from 51.2% in 2017 to 29.2% in 2020. Among the 52 out of 64 herds that accepted to continue the proposed CCP after the first year, 41 (78.8%) joined in 2020 the VNCP, that assessed the health ranking of the herds. The results provide evidence that a control plan based on a farm-specific strategy and a subsidized testing process can effectively reduce the impact of paratuberculosis in dairy herds, especially in convincing farmers to continue in paratuberculosis control by joining the VNCP, including them in a National context and increasing their awareness of the disease.