First report of Salmonella 1,4,[5],12:i:- in free-ranging striped dolphins (Stenella coeruleoalba), Italy

Between 2015 and the beginning of 2018 (January-March), 30 cetaceans were found stranded along the Ligurian Sea coast of Italy. Necropsies were performed in 22 cases and infectious diseases resulted the most common cause of death. Three striped dolphins, showed a severe coinfection involving the monophasic variant of Salmonella Typhimurium (Salmonella 1,4,[5],12:i:-). The isolates were characterized based on antimicrobial resistance, Multiple-Locus Variable-number tandem-repeat Analysis (MLVA) and whole-genome sequencing (WGS). All isolates demonstrated the same multidrug resistant genotype (ASSuT isolates), showed three different MLVA profiles, two of which closely related, and were identified as Sequence Type 34. Moreover, Single nucleotide polymorphisms (SNP) analysis confirmed strong correlations between two out of the three isolates. To our knowledge, S. 1,4,[5],12:i:-, one of the most common serovars in cases of human infection and food sources worldwide, has not previously been described in marine mammals, and reports of Salmonella-associated disease in free-ranging cetaceans are rare. These results highlight the role of cetaceans as sentinel species for zoonotic and terrestrial pathogens in the marine environment, suggest a potential risk for cetaceans and public health along the North Western Italian coastline and indicate cetaceans as a novel potential reservoir for one of the most widespread Salmonella serovars.

A cross-sectional study to identify a set of risk factors for caprine herpesvirus 1 infection

BACKGROUND

Caprine herpesvirus 1 (CpHV-1) causes neonatal mortality and reproductive failure in goats. Despite its impact on herd reproductive performance, few studies have investigated the risk factors associated with CpHV-1 infection. The aim of this cross-sectional study was to identify potential herd- and host-level risk factors associated with CpHV-1 prevalence in a goat population with heterogeneous seropositivity for CpHV-1.

RESULTS

Blood samples and individual data from 4542 goats were collected from 255 herds in Piedmont, Italy. Enzyme-linked immunosorbent assay (ELISA) and serum neutralization tests were carried out to detect antibodies against CpHV-1. A mixed-effects model was applied to identify any statistical association between CpHV-1 seropositivity and a set of putative host-level and herd-level risk factors. A total of 630 samples tested were found positive by ELISA (prevalence = 13.9%; 95% confidence interval (CI) 12.9-14.9). Of the 255 tested herds, 85 were classified as positive for the presence of at least one gB-positive animal (herd prevalence 33.3%, 95% CI 27.5-39.2), with a within-herd prevalence between 0.7 and 100% (Q1 = 17.6%; median = 32.3%; Q3 = 50%) (Q = quartiles). The prevalence ratios showed a statistical association with the following risk factors: breeds other than Saanen, older age, larger herd size, meat and extensive herds, and co-existence of CAEV-infected animals.

CONCLUSIONS

Results from this cross sectional study may help to elucidate the natural history of the infection and inform targeted strategies to control a disease with a potentially important impact on animal health and goat farming economy.

Prevalence of antibodies against Bubaline herpesvirus (BuHV-1) among Mediterranean water buffalo (Bubalus bubalis) with implications in buffalo trade

BACKGROUND

Both Bovine herpesvirus (BoHV-1) and Bubaline herpesvirus (BuHV-1) have been reported to cross the species barrier. Antibody seroconversion in glycoprotein E (gE) blocking ELISA during BuHV-1 infection has been documented. Recent diagnostic efforts have focused on the development and application of discriminatory tests to distinguish between infections with BoHV-1 and BuHV-1.

OBJECTIVE

To evaluate the impact and distribution of these two infections in water buffalo farms in two regions (Piedmont (n = 3) and Campania (n = 10), Italy) where infectious bovine rhinotracheitis control programs have been implemented.

ANIMALS AND METHODS

Sampling was carried out on 13 buffalo farms comprising 1089 animals using specific gE-indirect ELISA's test able to discriminate among BoHV-1 and BuHV-1 infections.

RESULTS

59.0% of animals reacted positive to ELISA (irrespective of whether BoHV-1 or BuHV-1 antigen was used) and 86.4% of these were reactive to BuHV-1 only, whereas 11.8% showed absorbance values for both antigens and were classified as inconclusive. There was a statistically significant age-related difference in BuHV-1 infection rates but not in overall individual (47% vs. 58%) or herd prevalence (100% vs. 90%) of infection between the two regions.

CONCLUSION

The low percentage of sera reactive to BoHV-1 (1.8%, 12/643) indicates that BuHV-1 may be the main circulating alphaherpesvirus infection in Mediterranean water buffalo in the two study areas. Since Bubalus bubalis is included in Directive 64/432/EEC on animal health problems affecting intra-community trade in bovine animals, diagnostic testing with nonspecific ELISA for BoHV-1 infection in buffalo may yield false-positive reactions. This scenario could lead to economic losses and hamper buffalo trade and movement, particularly for reproduction purposes.

Hepatitis E Virus: A Cross-Sectional Serological and Virological Study in Pigs and Humans at Zoonotic Risk within a High-Density Pig Farming Area

An increase in autochthonous hepatitis E virus (HEV) infections has been recorded in Italy suspected to be zoonotically transmitted from pigs; this study was carried out to determinate the seroprevalence and risk factors associated with hepatitis HEV exposition, both in swine and humans working in pig farms, located within a high-density pig farming area in Piedmont region, north-western Italy. The presence of viral RNA in human and swine samples was also evaluated, and phylogenetic analysis was performed on HEV-positive samples. Forty-two swine farms were sampled; 142 workers were enrolled in the study and classified into two groups: (i) 69 workers with occupational contact with swine (including veterinarians and farmers) recruited in the 42 sampled farms; (ii) 73 without occupational contact with swine. Forty-one of 42 (97%) swine farms resulted positive to enzyme-linked immunosorbent assay test for HEV antibodies (Abs). Overall seroprevalence in swine was 50% (441/879), with seropositivity rate higher in sows (333/469, 71%). HEV RNA in stool samples was detected in animals from 13 of 42 tested farms (31%), and a higher positivity resulted in weaners (40/246, 16.3%). Phylogenetic analysis classified all HEV isolates within genotype 3 (subtypes 3f, 3e, 3c). All humans were negative for HEV viral genome in blood. Five of 142 sera were positive for IgG anti-HEV with an overall prevalence of 3.52% with no statistically significant differences in prevalence rates between workers at zoonotic risk and the control group (5.7% versus 1.3%). In contrast, a significant difference (OR 10.1) was observed within the subgroup including subjects exposed for short periods (veterinarians) compared with those who worked for long periods (farmers) suggesting a correlation between the time of exposure and the likelihood of HEV infection. Reporting HEV infection is not mandatory in Italy, but a constant epidemiological surveillance should be ensured to clarify the epidemiology of this disease.

Hepatitis E Virus: First Description in a Pet House Rabbit. A New Transmission Route for Human?

In this work, we identified for the first time hepatitis E virus (HEV) in a pet house rabbit, an adult 7 years old female of domestic rabbit (Oryctolagus cuniculus). Importantly, the resulting phylogenetic tree showed that the HEV strain identified in the pet house rabbit was closely related to a human HEV sequence; this finding reawakens concerns regarding the zoonotic risk represented by HEV in animals and expands to house rabbit the spectrum of potential source of infection for humans. Potential for domestic transmission of HEV to humans should be taken into account.

Serological and virological survey of hepatitis E virus in wild boar populations in northwestern Italy: detection of HEV subtypes 3e and 3f

Although rare in developed countries, most acquired human cases of hepatitis E virus (HEV) infection are associated with travel to developing countries where HEV is endemic. Increasingly, however, sporadic, non-travel-related HEV cases have been reported in developed countries. In Italy, only two studies to date have investigated the presence of HEV in wild boars. Here, we report a serological and virological survey of HEV in wild boar populations in northwestern Italy. During the hunting season, 594 serum and 320 liver samples were collected and screened for antibodies to HEV and HEV RNA. Overall, the seroprevalence was 4.9 %, and HEV RNA was detected in 12 liver samples (p = 3.7 %). No serum samples tested positive for HEV RNA. Phylogenetic analysis of the ORF2 region revealed that the isolates clustered within genotype 3, subtypes 3e and 3f, and were closely related to HEV strains previously detected in domestic pigs farmed in the same geographic area. Although the routes of viral transmission are still poorly understood, our data show that HEV genotypes 3e and 3f circulate in wild boars in northwestern Italy. Also, they provide evidence that autochthonous HEV infections in Italy could also be linked to wild boar populations, suggesting an increased risk for domestically acquired HEV infection in humans through wild animals. The HEV sequences determined in this study may be useful for comparing present and future human isolates to identify transmission events between wild boar, humans, and farmed pigs. Similarly to other more commonly known zoonotic agents, HEV should be included in national or regional disease surveillance programs for wild animals.

Evaluation of viral inactivation of pseudorabies virus, encephalomyocarditis virus, bovine viral diarrhea virus and porcine parvovirus in pancreatin of porcine origin

Pancreatin is a substance containing enzymes, principally amylase, lipase, and protease. It is obtained from bovine or porcine pancreas and used in the treatment of pancreatic endocrine insufficiency in humans. Regulations and safety concerns mandate viral clearance (virus removal or inactivation) in biopharmaceuticals such as pancreatin. A virus validation study was performed to evaluate virus clearance achieved in the final step of drying under vacuum by testing a panel of four animal viruses: Pseudorabies virus (PRV), Encephalomyocarditis virus (EMCV), Bovine viral diarrhea virus (BVDV), and Porcine parvovirus (PPV). Because of the product's virucidal effect and high cytotoxicity, the starting material was diluted to a ratio of 0.67 g of dried pancreatin resuspended in 13.5 mL of cell culture medium followed by a 50-fold dilution in cell culture medium before spiking. After heating at 60±1°C for 5 h, the samples were diluted about 5-fold in cell culture medium and titered by the plaque assay method. The virus reduction factor ranged from 5.59 (for PPV) to 7.07 (for EMCV) and no viral plaque was observed, indicating that the process step was effective in the reduction and removal of virus contamination. Though no virus contamination events in pancreatin have been reported to date, evaluation of the production process for its ability to inactivate and/or remove virus contamination, particularly from zoonotic viral agents such as hepatitis E virus and Norovirus considered emerging pathogens, is necessary to ensure the viral safety of animal-derived biopharmaceuticals.

Expression and antigenic characterization of bubaline herpesvirus 1 (BuHV1) glycoprotein E and its potential application in the epidemiology and control of alphaherpesvirus infections in Mediterranean water buffalo

Bubaline herpesvirus 1 (BuHV1) is a member of ruminant alphaherpesviruses antigenically related to bovine herpesvirus 1 (BoHV1). The impact of BuHV1 infection in infectious bovine rhinotracheitis control program is difficult to establish, due to the lack of specific diagnostic test. The ectodomain of glycoprotein E of BuHV1 was expressed as recombinant secreted protein and used in indirect ELISA as well as in a discriminatory test using the BoHV1 counterpart. A panel of monoclonal antibodies was produced against BuHV1; 6 out of 7 anti-gE monoclonal antibodies specifically recognized the BuHV1 gE. Results indicated BuHV1 gE as a sensitive marker of infection compared to seroneutralization (SN) test or blocking ELISA. When BoHV1 and BuHV1 gEs were immobilized in different wells of the same ELISA microplate, bovine and water buffalo sera were more reactive against the respective infecting virus. About one third of seropositive buffaloes with no history of contact with cattle and having higher SN titres, reacted in BoHV1 gE blocking ELISA, possibly because of steric hindrance. Since in two occasions BuHV1 was also isolated from water buffalo scoring gB+/gE+ BoHV1 blocking ELISA, we conclude that the combination of the two blocking ELISAs is not suitable to differentiate between BoHV1 and BuHV1.