Porcine reproductive and respiratory syndrome (PRRS) affects farmed swine causing heavy direct and indirect losses. The infections sustained by PRRS viruses (PRRSV-1 and PRRSV-2) may give rise to severe clinical cases. This highlights the issue of PRRSV pathogenicity and relevant markers thereof. Since PRRSV strains can be discriminated in terms of immunotypes, we aimed to detect possible correlates of virulence in vitro based on the profile of innate immune responses induced by strains of diverse virulence. To this purpose, 10 field PRRSV isolates were investigated in assays of innate immune response to detect possible features associated with virulence. Tumor necrosis factor-α, interleukin (IL)-1beta, IL-8, IL-10, and caspase-1 were measured in cultures of PRRSV-treated peripheral blood mononuclear cells of PRRS-naive pigs, unable to support PRRSV replication. Two reference PRRSV strains (highly pathogenic and attenuated, respectively), were included in the screening. The PRRSV strains isolated from field cases were shown to vary widely in terms of inflammatory cytokine responses in vitro, which were substantially lacking with some strains including the reference, highly pathogenic one. In particular, neither the field PRRSV isolates nor the reference highly pathogenic strain gave rise to an IL-1beta response, which was consistently induced by the attenuated strain, only. This pattern of response was reversed in an inflammatory environment, in which the attenuated strain reduced the ongoing IL-1beta response. Results indicate that some pathogenic PRRSV strains can prevent a primary inflammatory response of PBMCs, associated with reduced permissiveness of mature macrophages for PRRSV replication in later phases.

The complex health problem of antimicrobial resistance (AMR) involves many host species, numerous bacteria and several routes of transmission. Extended-spectrum β-lactamase and AmpC (ESBL/AmpC)-producing Escherichia coli are among the most important strains. Moreover, wildlife hosts are of interest as they are likely antibiotics free and are assumed as environmental indicators of AMR contamination. Particularly, wild boar (Sus scrofa) deserves attention because of its increased population densities, with consequent health risks at the wildlife–domestic–human interface, and the limited data available on AMR. Here, 1504 wild boar fecal samples were microbiologically and molecularly analyzed to investigate ESBL/AmpC-producing E. coli and, through generalized linear models, the effects of host-related factors and of human population density on their spread. A prevalence of 15.96% of ESBL/AmpC-producing E. coli, supported by blaCTX-M (12.3%), blaTEM (6.98%), blaCMY (0.86%) and blaSHV (0.47%) gene detection, emerged. Young animals were more colonized by ESBL/AmpC strains than older subjects, as observed in domestic animals. Increased human population density leads to increased blaTEM prevalence in wild boar, suggesting that spatial overlap may favor this transmission. Our results show a high level of AMR contamination in the study area that should be further investigated. However, a role of wild boar as a maintenance host of AMR strains emerged.

No abstract

Information regarding the relationship between animal welfare (AW) and antimicrobial use (AMU) in dairy cows is limited. The current study aimed to investigate this relationship on Italian farms and to identify potential targets of AMU reduction. The study was performed at 79 Italian dairy farms housing over 15,000 cows during 2019. AW was scored with an on-farm protocol assessing farm management and staff training, housing systems, and animal-based measures. AMU was estimated using a defined daily dose per kg of animal biomass (DDDAit/biomass) for Italy. The median AW score was 73% (range: 56.6–86.8%). The median AMU was 4.8 DDDAit/biomass (range: 0–11.8). No relationship between the total AMU and AW was found. Management and staff training were positively associated with the use of the European Medicines Agency’s category B antimicrobials, which are critical for human medicine, and with intramammary products for dry cow therapy. In those farms, antimicrobial stewardship should aim to reduce the category B antimicrobials and selective dry cow therapy. Our results underline the importance of implementing both an integrated monitoring system (AW, AMU, etc.) and antimicrobial stewardship tailored to the specific needs of each dairy farm.

Data on antimicrobial use (AMU) in heavy pig production (>150 kg) are limited. The aim of this study was to investigate the AMU in this production. Data from 2015 were collected for 143 fattening farms. The AMU was estimated through a treatment index per 100 days (TI100) using the defined daily dose animal for Italy (DDDAit). When possible, a comparison with the European Medicines Agency’s defined daily doses for animals (DDDvet) was performed. The median TI100 was 10.7 (range, 0.2–49.5). Group treatments represented 94.6% of overall consumption. The AMU calculated using DDDAit and DDDvet were strongly correlated (ρ = 0.976; p < 0.001). The AMU was negatively correlated with injectables use (ρ = −0.46, p < 0.001) and positively correlated with oral products (ρ = 0.21, p = 0.014), premixes (ρ = 0.26, p = 0.002), and mortality (ρ = 0.18; p = 0.027). Farm size was negatively correlated with AMU (ρ = −0.29, p < 0.001). Smaller farms were more frequently above the median TI100 (odds ratio = 2.3, 95% confidence interval = 1.2–4.7), suggesting that they may have lower biosecurity and management standards. The results of this study should provide useful insights for the development of an Italian monitoring system.