Evidence of Circulation and Phylogenetic Analysis of Hepatitis E Virus (HEV) in Wild Boar in South-East Italy.

Hepatitis E virus (HEV) is an important cause of acute viral hepatitis in humans worldwide. The food-borne transmission of HEV appears to be a major route in Europe through the consumption of pork and wild boar meat. HEV epidemiology in wild boars has been investigated mainly in Northern and Central Italian regions, whilst information from Southern Italy is limited. We investigated the occurrence of HEV in wild boar in the Apulia and Basilicata regions (Southern Italy). Thirteen (10.4%) out of one hundred and twenty-five wild boar samples tested positive for HEV using a quantitative reverse transcription PCR. HEV prevalence was 12% in Apulia and 9.3% in Basilicata. Seven samples were genotyped, and different subtypes (c, f, m) of genotype 3 were identified. The complete genome of a 3m strain was determined, and the virus showed the highest nucleotide identity to a human HEV strain identified in France in 2017. These findings demonstrate the substantial circulation of HEV in the wild boar population in Italian Southern regions. Gathering information on the HEV strains circulating in different geographical areas is useful for tracking the origin of HEV outbreaks and assessing the epidemiological role of wild boar as a potential virus reservoir for domestic pigs.

Occurrence of a New Variant of Salmonella Infantis Lacking Somatic Antigen.

Salmonella Infantis is one of the most frequent serovars reported in broilers and is also regularly identified in human salmonellosis cases, representing a relevant public health problem. In the laboratories of the Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZSPB), six Salmonella Infantis strains with antigenic formula -:r:1,5 have been isolated from the litter and carcass of broilers between 2018 and 2022. The strains were investigated to evaluate their phenotype, antibiotic resistance and genomic profiles. Genomic analysis confirmed that the isolates belonged to the Infantis serotype and to the sequence type ST32. Moreover, all strains showed a multidrug-resistant (MDR) profile and were characterised by the presence of the IncFIB plasmid incompatibility group. Three strains had the blaCTX-M-1 gene, and one of them carried IncX1. The presence of this new variant of S. Infantis is particularly relevant because it could expand the landscape of the S. Infantis population. The absence of the somatic antigen could pose a problem in both isolation and serotyping and a consequent public health concern due to the spread of Salmonella infection.

Systematic Survey of Vibrio spp. and Salmonella spp. in Bivalve Shellfish in Apulia Region (Italy): Prevalence and Antimicrobial Resistance.

The emergence of antimicrobial resistance (AMR) is increasingly common across the globe and aquatic ecosystems could be considered a reservoir of antibiotic-resistant bacteria. This study aimed to determine prevalence and antibiotic susceptibility of the potential pathogenic bacteria Salmonella spp. and Vibrio spp. in bivalve molluscs intended for human consumption, collected over a period of 19 months along the northern coast of Apulia region. The AMR profile was also determined in non-pathogenic Vibrio species, common natural inhabitants of seawater and a useful indicator for the surveillance of AMR in the environment. The current study presents data on the AMR of 5 Salmonella and 126 Vibrio isolates by broth microdilution MIC. Multidrug resistance (MDR) was observed in one S. Typhimurium strain towards sulfamethoxazole, trimethoprim, tetracycline, gentamicin, and ampicillin and in 41.3% of the Vibrio strains, mostly towards sulphonamides, penicillin, and cephems. All Vibrio isolates were sensitive to azithromycin, chloramphenicol, tetracycline, amoxicillin/clavulanic acid, gentamicin, streptomycin, amikacin, and levofloxacin. The AMR phenomenon in the investigated area is not highly worrying but not entirely negligible; therefore, in-depth continuous monitoring is suggested. Results concerning the antibiotic agents without available specific clinical breakpoints could be useful to upgrade the MIC distribution for Vibrio spp. but, also, the establishment of interpretative criteria for environmental species is necessary to obtain a more complete view of this issue.

Isolation and characterization of Yersinia enterocolitica from foods in Apulia and Basilicata regions (Italy) by conventional and modern methods.

Yersiniosis is the third most reported food-borne zoonosis in Europe. The aim of the present study was to perform the search for Yersinia enterocolitica in food samples collected from Apulia and Basilicata regions (Southern Italy) and to characterize any isolates by classical and modern analytical methods. A total of 130 samples were analyzed between July 2018 and July 2019: most of them were raw milk and dairy products made from it. Furthermore, 8 out of 130 samples were individual milk samples collected from bovines reared in a Brucella-free farm which showed false positive serological reaction for brucellosis due to the presence of pathogenic Y. enterocolitica O:9 biotype 2 in faeces. The Real Time PCR targeting the ail gene and the culture method were performed to detect pathogenic Y. enterocolitica. Isolates were subjected to API 20E (Biomerieux) and MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time-of-Flight) for species identification. All samples were negative for the ail gene. The culture method allowed to isolate suspicious colonies from 28 samples. The API 20E system and the MALDI-TOF MS technique identified 20 Y. enterocolitica and 1 Y. intermedia in a concordant way. The remaining 7 strains were all identified as Y. enterocolitica by the API 20E system, while the MALDI-TOF MS recognized 4 Y. intermedia, 1 Y. bercovieri and 2 Y. massiliensis. Genotypic characterization of the discordant strains was performed by rMLST and it confirmed the MALDI-TOF MS' results. Only non-pathogenic Y. enterocolitica biotype 1A strains were found, although with a non-negligible prevalence (P = 0.15 with CI 95% = ± 0.06). This study indicates a poor circulation of pathogenic Y. enterocolitica in food products made and marketed in the investigated areas. However, the small number of samples, insufficient for some food categories such as meat and vegetable, does not allow to exclude the presence of pathogenic strains at all.

Evaluation of Antimicrobial Resistance in Salmonella Strains Isolated from Food, Animal and Human Samples between 2017 and 2021 in Southern Italy.

Salmonella enterica is one of the most common causes of foodborne infection in the world, and the most common one in Italy. Italy collaborates with the other EU member states to survey the antimicrobial resistance of Salmonella on a large scale. This study on the situation in Apulia and Basilicata provides a more focused point of view on the territory, and anticipates the data reported in future Italian reports. Antimicrobial resistance was detected using the MIC detection method, with EUVSEC® plates, on the strains collected between 2017 and 2021. The results of serotyping showed that Salmonella Infantis is the serovar that has increased the most over time in veterinary samples, while Salmonella Tyhimurium and its monophasic variant are the most isolated in human samples. The results of the antimicrobial resistance study comply with European data, showing high resistance to quinolones, tetracyclines, ampicillin and trimethoprim, and low resistance to colistin and cephems. The significant exception was that all strains were resistant to sulphametoxazole. The presence of MDRs, which was 85% in veterinary and 77.4% in human strains, often included critically important antibiotics, which is a sign that more study and action is needed to manage the use of antibiotics.

Salmonella Infection in Turtles: A Risk for Staff Involved in Wildlife Management?

Monitoring of infections that may be transmitted to humans by animals in wildlife rescue centres is very important in order to protect the staff engaged in rehabilitation practices. Salmonella may be a natural inhabitant of the intestinal tract of turtles, rarely causing disease. This may represent a potential risk for humans, increasing the sanitary risk for operators in wildlife rescue centres. In this paper, the occurrence of non-typhoidal Salmonella among terrestrial turtles housed in a wildlife rescue centre in Southern Italy was investigated, in order to assess the serovars more frequently carried by turtles and identify those that may represent a risk for operators involved in wildlife management. Sixty-nine adult turtles (Testudo hermanni hermanni, T. h. boettgeri, T. graeca, and T. marginata) were tested. Detection and serotyping of Salmonella strains were performed according to ISO 6579-1 and ISO/TR 6579-3:2013, respectively. The distribution of Salmonella spp. was significantly higher in T. hermanni hermanni than in other species, independent of the age and gender of the animals. Two different Salmonella species, S. enterica and S. bongori, three S. enterica subspecies (enterica, diarizonae, salamae), and five different serovars (Hermannswerder, Abony, Ferruch, Richmond, Vancouver) within the group S. enterica subspecies enterica were identified. Different combinations of Salmonella types were simultaneously found in specimens of T. h. hermanni. Most of detected Salmonella types may represent a potential risk for public health. Adopting correct animal husbandry procedures and informing on potential sanitary risks may be useful for minimising the risk of transmission of Salmonella to workers involved in wildlife management.

Prevalence of anisakid parasites in fish collected from Apulia region (Italy) and quantification of nematode larvae in flesh.

Anisakis spp. and Hysterothylacium spp. are nematodes that commonly parasitize several fish species. Nematode larvae can be recovered in coelomic cavity and viscera, but also in flesh and have an important economic and public health impact. A total of 1144 subjects of wild teleosts, 340 samples of cephalopods and 128 specimens of farmed fish collected from Apulia region were analysed for anisakid larvae detection by visual inspection of coelomic cavity and viscera and by digestion of the flesh. No nematode larvae were found in farmed fish and cephalopod molluscs. All examined wild-caught fish species were parasitized, except for 5 species for each of which only a few subjects belonging to the same batch were sampled, therefore the results are just indicative. A total of 6153 larvae were isolated; among these, 271 larvae were found in the muscular portion. Larvae were identified by morphological method as belonging to the genera Anisakis (97.2%) (type I and type II) and Hysterothylacium (2.8%). Both nematodes could be found in all fish species, except for round sardinella (Sardinella aurita), infected only by Hysterothylacium spp. and for Mediterranean scaldfish (Arnoglossus laterna), little tunny (Euthynnus alleteratus) and chub mackerel (Scomber japonicus) infected only with Anisakis spp.. A sample of 185 larvae was sent to the National Reference Centre for Anisakiasis (C.Re.N.A.) of Sicily for identification at the species level: 180 larvae belonged to the species A. pegreffii and 2 larvae to A. physeteris. The remaining 3 larvae were identified at genus level as Hysterothylacium. Statistical indices such as prevalence, mean intensity and mean abundance were calculated. Chub mackerel (S. japonicus) was the species with the highest prevalence and mean intensity. Moreover, the average and the median values of larvae per 100 g of edible part for each fish species were determined to estimate the consumer exposure to Anisakis spp.. The obtained values were then recalculated by referring to the edible part of all specimens (infected and non-infected) forming a single parasitized batch, getting more realistic and objective data useful for risk assessment. Our results indicate that the consumption of raw or undercooked wild fish caught off Apulian coasts could result in the acquisition of anisakiasis; on the contrary, farmed fish and cephalopods appear to be safer for the consumer.