Prevalence and antimicrobial resistance profiles of Salmonella spp. in poultry meat.

The spread of multidrug resistant (MDR) Salmonella strains, along the poultry supply chain, can represent a relevant threat to human health. This study aimed to evaluate the prevalence and antimicrobial resistance of Salmonella spp. isolated from poultry meat for human consumption. Between 2019 and 2021, 145 samples were analyzed according to ISO 6579-1:2017. The strains isolated were identified by using biochemical-enzymatic assays and serotyping, according to the Kauffmann-White-Le Minor scheme. The antibiotic susceptibility tests were determined using the Kirby-Bauer method. Forty Salmonella spp. strains were isolated and serotyping showed Salmonella Infantis to be predominant. 80% of the isolated strains were MDR and identified as S. Infantis. This study confirms the circulation of MDR Salmonella isolated from poultry meat and highlights the predominance of the S. Infantis serovar, which represents an emerging risk factor under the One Health holistic approach.

Cultivable Bacteria Associated with the Microbiota of Troglophile Bats.

BACKGROUND: The study of bats is of significant interest from a systematic, zoogeographic, ecological, and physiological point of view. The aim of this study is to investigate the culturable aerobic enteric, conjunctival, and oral bacterial flora of bats to determine their physiological microbiome and to investigate the possible occurrence of pathogenic bacteria. METHODS: Five hundred and sixty-seven samples were collected from 189 individuals of four species of troglophile bats (Myotis myotis, Myotis capaccinii, Miniopterus schreibersii, and Rhinolophus hipposideros) living in Sicilian and Calabrian territory (Italy). All samples were tested for Gram-negative bacteria; conjunctival and oral swabs were also submitted to bacteriological examination for Gram-positive bacteria. RESULTS: Four hundred thirteen Gram-negative strains were isolated. Of these, 377 belonged to 17 different genera of the family Enterobacteriaceae and 30 to five other families. One hundred eighty-three Gram-positive strains were isolated. Of these, 73 belonged to the Staphylococcaceae family, 72 to the Bacillaceae family and 36 to four other families. Besides some potentially pathogenic strains, several bacterial species have been found that are common to all the bat species studied. These could perhaps play a physiological or nutritional role. CONCLUSION: A great variety of bacterial species were identified in the cultivable microbiota of southern-Italian troglophile bats, including several potentially pathogenic strains and numerous putatively symbiotic species.

Food Is Reservoir of MDR Salmonella: Prevalence of ESBLs Profiles and Resistance Genes in Strains Isolated from Food.

Salmonella spp. are among the most frequent causes of foodborne diseases, and the increasing occurrence of MDR strains is an additional cause for concern. In the three-year period 2019-2021, we collected Salmonella spp. strains isolated from different food categories analysed in the context of Regulation (EC) No 2073/2005 in order to assess their antibiotic susceptibility profiles and ESBL production. To determine the susceptibility profiles and identify MDR strains, we used the Kirby-Bauer method to test 17 antibiotics. Double-disc and PCR testing then allowed us to assess the production of ESBLs and the presence of beta-lactamase resistance genes. Phenotypic tests showed that 36 out of 67 strains were MDR and 52.7% of these were ESBL producers. Finally, molecular investigations conducted on ESBL-producing strains revealed the presence of blaSHV, blaCTX-M and blaTEM genes. Our results confirmed the prevalence of S. Infantis, an MDR strain and ESBL producer, in chicken meat. This suggests that further research on the prevalence of antibiotic resistance genes (ARGs) in foodborne strains is needed, especially from a One Health perspective.

Diagnostic Findings in a Confirmed Outbreak of Brucella ovis Infection in a Traditional Sheep Farm in Sicily (South-Italy).

Aim of this study is to report a laboratory investigation performed following the isolation of Brucella ovis, causing ovine epididymitis, in a traditional sheep farm in Sicily (South Italy). This disease represents a newly emerging risk for Italian livestock and is listed among diseases of EU priority (EU Reg 2016/429). Blood samples from 56 rams and 143 ewes were analyzed by both Enzyme-Linked Immunosorbent Assay (ELISA) and Complement Fixation Test (CFT). Genital swabs from all rams and 15 lactating ewes were collected to perform real-time PCR. Eighteen serologically positive rams were slaughtered and postmortem-inspected. Samples of testicle, epididymis, lymph nodes, and urine were also collected in order to perform microbiological, molecular, and histopathological analysis. Twelve slaughtered rams showed anatomo-pathological lesions. Real-time PCR for B. ovis BOV_A0504 gene was positive for 13 testicles and epididymis and 11 urine while B. ovis was isolated from epididymis and testicles of 7 slaughtered rams. This is the first exhaustive laboratory report of a microbiological, molecular, and serological pattern of the disease in sheep in Italy. Despite the impact on health and animal welfare, the epidemiology of B. ovis infection is still unknown, particularly in our country where the disease is considered endemic.

Salmonella serovar distribution from non-human sources in Italy; results from the IT-Enter-Vet network.

The study summarises the results obtained over the period 2002-2013 by the Italian IT-Enter-Vet network, aimed at collecting data on Salmonella isolates from non-human sources. A total of 42,491 Salmonella isolates were reported with a progressive decrease over the years. S. Typhimurium was the most frequent serovar up to 2011, but then, it was overtaken by S. 4,[5],12,:i:-, S. Derby, S. Livingstone and S. Enteritidis alternated as the third most commonly isolated serovars. With regard to the sources of isolation, S. Typhimurium was distributed ubiquitously among the animal species. On the contrary, S. 4,[5],12,:i:- and S. Derby were strictly associated with pigs, whereas S. Livingstone, S. Enteritidis and S. Infantis were clearly related to poultry. Intriguingly, when the frequency of serovar distribution along the food chain was considered, it was evident that S. Typhimurium and S. Derby tended to persist along the chain, as they were isolated even more frequently from foods than from animals. A similar distribution was found for S. Enteritidis and S. Hadar. Despite limitations related to non-mandatory participation of laboratories in the network, the data presented are valuable to obtain a picture of the evolution of Salmonella from non-human sources over time in Italy.

Antibiotic Resistance Profiling, Analysis of Virulence Aspects and Molecular Genotyping of Staphylococcus aureus Isolated in Sicily, Italy.

Staphylococcus aureus is the major cause of foodborne diseases worldwide. In this retrospective study, 84 S. aureus strains were characterized. The collection comprises 78 strains isolated during 1998 and 2014 from dairy products and tissue samples from livestock bred for dairy production in Sicily. One isolate was obtained from a pet (dog), one from an exotic animal (a circus elephant), and four human isolates were obtained during a severe food poisoning outbreak that occurred in Sicily in 2015. All the strains were characterized by pulsed-field gel electrophoresis (PFGE), for antibiotic resistance and presence of toxin genes. PFGE results showed 10 different pulsotypes, with three relatively frequent and three unique. The antibiotic resistance profiling showed that penicillin G (35.7%) and tetracycline (20.2%) resistance is largely spread. Most isolates contained at least one toxin gene making them a potential threat for public health. Enterotoxin sec gene was observed in 28.6% and seg in 23.8% of the strains, respectively; the human isolates were the only ones to concurrently harbor both seg and sei genes. In addition, 24 isolates were randomly selected and analyzed by multilocus sequence typing. Interestingly, the analysis showed the presence of 12 sequence types (STs), of which 6 were novel. One of them, ST700, was detected in 29% of the isolates and was found to be spread throughout Sicily. ST700 has been present in the island for almost 16 years (1998-2014) and it shows no host preference since it was isolated from different ruminant species. Four human isolates shared both the pulsotype (PT10) and the sequence type (ST9), as well as the virulence genes (seg-sei); this observation suggests that the isolates originated from a single clone, although they were obtained from two different individuals.

Staphylococcal food poisoning case and molecular analysis of toxin genes in Staphylococcus aureus strains isolated from food in Sicily, Italy.

A case of staphylococcal food poisoning was observed in two individuals of the same family after consumption of primosale, a semiripened sheep cheese produced in Sicily. Staphylococcus aureus isolated from the cheese produced enterotoxin C (SEC) and carried both the enterotoxin C (sec) and the toxic shock syndrome toxin (tsst-1) gene. Following this case, an extensive survey was conducted on 971 food samples (raw milk, cheese, meat, and food preparations). S. aureus was detected in 102 of 971 food samples, from all types of food with the exception of ricotta cheese. The tsst-1 gene was present in 42% of the strains, either alone or in combination with other toxin genes. The enterotoxin C gene was the most represented enterotoxin, but it was only found in dairy products. Six S. aureus isolates carried the sea gene alone, two isolates carried both sea and seb, and one isolate carried both sea and sec. A significant percentage (46%) of all isolates carried a toxin gene, creating significant concern that virulent S. aureus can be transmitted through food in Sicily.