The spread of resistant bacteria from livestock to the food industry promoted an increase of alternative poultry production systems, such as organic and antibiotic-free ones, based on the lack of antimicrobial use, except in cases in which welfare is compromised. We aimed to investigate the antibiotic susceptibility of commensal Escherichia coli isolated from organic, antibiotic-free, and conventional broiler farms and slaughterhouses toward several antimicrobials critically important for human health. To assess antimicrobial susceptibility, all E. coli isolates and extended spectrum beta-lactamase (ESBL) E. coli were analysed by the microdilution method. The prevalence of tigecycline, azithromycin and gentamicin E. coli-resistant strains was highest in organic samplings. Conversely, the lowest prevalence of resistant E. coli strains was observed for cefotaxime, ceftazidime and ciprofloxacin in organic systems, representing a significant protective factor compared to conventional systems. All E. coli strains were colistin-susceptible. Contamination of the external environment by drug-resistant bacteria could play a role in the presence of resistant strains detected in organic systems. Of interest is the highest prevalence of cephalosporin resistance of E. coli in conventional samplings, since they are not permitted in poultry. Our results suggest that monitoring of antibiotic resistance of the production chain may be helpful to detect “risks” inherent to different rearing systems.

Local livestock breeds are pivotal to ensure sustainable agriculture and represent a real genetic resource in the context of genetic variability reduction. This study aimed at broadening the knowledge about hematological values in female Verzaschese and Camosciata delle Alpi goats (an Italian local and a cosmopolitan goat breed, respectively) and investigating factors affecting them (i.e., breed, age, season). Blood samples were collected monthly from 34 Verzaschese and 37 Camosciata delle Alpi female goats kept under the same semi-extensive farming system for a whole year. The main hematological parameters were evaluated, and descriptive as well as inferential statistical analyses were performed. Reference intervals for complete blood cell count were established and several inter-breed differences were found. In particular, most of the red blood cell parameters were higher in Verzaschese than Camosciata delle Alpi (p < 0.05) suggesting a greater gastrointestinal parasites’ resilience of the local breed. The age effect (p < 0.05) was consistent with the literature while the season effect (p < 0.05) could be explained by the melatonin immunostimulant action and gastrointestinal parasitism influence. Overall, differences in blood values could be attributed to physiological changes and adaptive strategies developed through centuries highlighting the remarkable rusticity and adaptation to the environment and farming system of the local breed.

This work aimed to evaluate phenotypically and genotypically the colistin susceptibility of 85 Salmonella Infantis strains isolated in Italy from the broiler production chain, and to apply a whole-genome approach for the determination of genes conferring antimicrobial resistance (AMR). All isolates were tested by the broth microdilution method to evaluate the colistin minimum inhibitory concentrations (MICs). A multiplex PCR was performed in all isolates for the screening of mcr-1, mcr-2, mcr-3 mcr-4, mcr-5 genes and whole-genome sequencing (WGS) of six S. Infantis was applied. Three out of 85 (3.5%) S. Infantis strains were colistin resistant (MIC values ranged from 4 to 8 mg/L) and mcr-1 positive. The mcr-1.1 and mcr-1.2 variants located on the IncX4 plasmid were detected in three different colistin-resistant isolates. The two allelic variants showed identical sequences. All six isolates harbored blaCTXM-1, aac(6′)-Iaa and gyrA/parC genes, mediating, respectively, beta-lactam, aminoglycoside and quinolone resistance. The pESI-megaplasmid carrying tet(A) (tetracycline resistance), dfrA1, (trimethoprim resistance) sul1, (sulfonamide resistance) and qacE (quaternary ammonium resistance) genes was found in all isolates. To our knowledge, this is the first report of the mcr-1.2 variant described in S. Infantis isolated from broilers chickens. Our results also showed a low prevalence of colistin- resistance, probably due to a reduction in colistin use in poultry. This might suggest an optimization of biosecurity control both on farms and in slaughterhouses.

The study was aimed at evaluating the presence of antibiotic-resistant Staphylococcus aureus in retailed raw chicken meat from retail stores intended for human consumption. The presence, characterization, and antibiotic susceptibility of S. aureus from 38 retail raw chicken meat samples was performed using a standard microbiological method involving mannitol salt agar (MSA) and Mueller-Hinton agar (MHA). All the samples were positive for Staphylococcus species, of which 34 (89.5%) were positive for S. aureus. The S. aureus isolates were most resistant to tetracycline (88.24%), erythromycin (82.35%), and chloramphenicol (61.77%). Nevertheless, decreased resistance towards gentamycin (23.53%) and cotrimoxazole (38.24%) were recorded. All the S. aureus isolates in this study were resistant to cloxacillin, amoxicillin, and augmentin (amoxicillin + clavulanic acid). The present findings show how the raw chicken meat samples could be a potential source of multidrug-resistant S. aureus strains dissemination. Therefore, this study suggests high-level contamination of meat with multidrug-resistant S. aureus and highlights the public health consequences of consuming such products. Undoubtedly, uncontrolled drugs in food animal production as growth stimulators or medicinal treatment present a possible consequence to people’s health. Having the aforementioned in mind, there is a necessity to control the use of drugs and monitor any residues left in the food intended for human consumption.

Colibacillosis, a bacterial infection caused by pathogenic Escherichia coli strains, poses significant challenges to contemporary poultry farming. This paper provides a succinct overview of key aspects related to the disease. Colibacillosis manifests with respiratory, enteric, and systemic clinical signs, impacting broilers, layers, and breeders. The etiology involves virulent E. coli strains with specific adhesion and invasion mechanisms. The avian immune response plays a crucial role, influenced by factors such as age, stress, and vaccination. The epidemiology exhibits global prevalence, influenced by geographical, seasonal, and farm-specific factors. Control strategies encompass biosecurity measures, vaccination, responsible antimicrobial use, genetic selection, and environmental management. Comprehensive understanding and proactive management of colibacillosis are essential to mitigate economic losses and sustain the health and productivity of poultry in modern production systems. In conclusion colibacillosis remains a significant challenge in modern poultry production, with economic implications for the industry. Efforts to control and manage colibacillosis in poultry production should take into consideration these multifaceted factors and focus on prevention, early detection, and responsible antimicrobial use.

Salmonella in pork is still a relevant safety issue in the EU, and specific regulations are in force to control this hazard in the meat chain, in a from farm to fork perspective. In Italy, the control is mainly based on official sampling at the slaughterhouse level. The prevalence of Salmonella, and isolated serovars, was investigated during a three-year survey in small and medium slaughterhouses in central Italy. A total of 400 pig carcasses samples were collected by official authorities during the observation period. Data were also analyzed according to the year and season of sampling. The overall Salmonella prevalence in the five selected abattoirs was 13%, with no differences due to the slaughterhouses size and seasons of sampling. An increasing trend in Salmonella prevalence was registered over the years. The main serovars detected were Salmonella enterica 4,[5],12:i:- and Derby. The data emphasized that the number of contaminated carcasses is relatively high with respect to the level set by EU legislation, and equally distributed in the area, and therefore, appropriate monitoring and control strategies also need to be developed at the farm level.