Swinepox virus: an unusual outbreak in free-range pig farms in Sicily (Italy).

BACKGROUND: Two outbreaks of swinepox were investigated in free-range domestic pig farms located in the northeastern side of Sicily, Italy. The disease is generally self-limiting with a low mortality rate, but morbidity can reach high rates in case of poor sanitary conditions, improper husbandry practices and ectoparasitic infestation. The presented cases are the first ever reported on the island and part of the few cases reported in domestic pigs. CASE PRESENTATION: Carcasses condemned at the slaughterhouse and deceased pigs from Farm A and Farm B respectively, were referred for post-mortem examination and further investigations, with a strong suspect of SwinePox virus (SWPV) infection. Twelve deceased pigs were examined in total, showing poor body condition and pustular lesions scattered all over the cutaneous surfaces. Moreover, pigs from Farm B showed ocular lesions classified from Grade I to IV (from mild conjunctivitis to severe keratoconjunctivitis with corneal oedema, opacity, and ulcers). Final diagnosis was pursued by the microscopic assessment of skin lesions in both farms, which revealed the typical SWPV-lesion appearance, such as severe and disseminated ulcerative dermatitis and suspected inclusion bodies multifocally observed in the epidermis. Moreover, negative staining Electron Microscopy (nsEM) was performed on skin lesions and ocular swabs from Farm B, revealing in two samples the presence of brick-shaped viral particles, 220 nm long and 160 nm wide, with irregularly arranged surface tubules, identified as SWPV. The gene encoding the 482-bp fragment of the virus late transcription factor-3 was detected by PCR and sequencing revealed 99.79% identity and 100% query-cover with a strain previously isolated in Germany. Field clinical assessment was then performed in Farm B, revealing high overcrowding, poor sanitary conditions and improper husbandry practices, which are relevant risk factors for SWPV transmission. CONCLUSIONS: The present is the first case report of SWPV in free-range pigs raised in Sicily, an island of the Southern coast of Italy, and wants to raise awareness on a neglected disease, and cause of animal health and welfare issues.

Comparative Study of Mycobacterium bovis and Mycobacterium avium subsp. paratuberculosis In Vitro Infection in Bovine Bone Marrow Derived Macrophages: Preliminary Results.

Bovine tuberculosis and paratuberculosis are endemic in many areas worldwide. This work aims to study cytokines production and gene expression profiles of bovine macrophages infected with Mycobacterium bovis and Mycobacterium paratuberculosis subsp. avium (MAP) strains to identify potential diagnostic biomarkers. Bovine bone marrow stem cells were differentiated into macrophages and subsequently infected in vitro with different spoligotypes of M. bovis and MAP field strains (as single infections and coinfections), using different multiplicity of infection. Supernatant and cell pellets were collected 24 h, 48 h, and one week post-infection. Preliminarily, gene expression on cell pellets of IL-1ß, IL-2, INFγ, IL-6, IL-10, IL-12, and TNFα was assessed by qRT-PCR one week p.i. Subsequently, IL-1ß and IL-6 were measured by ELISA and qRT-PCR to investigated their production retrospectively 24 h and 48 h p.i. A variability in macrophages response related to the concentration of mycobacteria, the coinfection with MAP, and M. bovis spoligotypes was identified. An early and constant IL-6 increase was observed in the M. bovis infection. A lower increase in IL-1ß was also detected at the highest concentration of the two M. bovis spoligotypes one week post-infection. IL-6 and IL-1 ß production was reduced and differently expressed in the MAP infection. IL-6 appeared to be the earliest cytokines produced by bovine macrophages infected with M. bovis.

Geo-epidemiology of animal tuberculosis and Mycobacterium bovis genotypes in livestock in a small, high-incidence area in Sicily, Italy.

Introduction: The persistence of animal tuberculosis (TB) in livestock is a major concern in Sicily, Italy. The objective of this study was to elucidate the transmission dynamics of M. bovis infection in a highly circumscribed, and at the same time geographically diverse, high-risk area of the island through an in-depth geo-epidemiological investigation of TB in cattle and black pigs raised in small-scale extensive farms across the district of Caronia. Methods: We used genotype analysis coupled with geographic information system (GIS) technology and phylogenetic inference to characterize the spatial distribution of TB and M. bovis genotypes in livestock and the genetic relationships between M. bovis isolates. A total of 589 M. bovis isolates collected from slaughtered cattle (n = 527) and Sicilian black pigs (n = 62) over a 5-year period (2014-2018) were included in the study. Results: TB was widespread throughout the district and was most frequent in the north-central area of the district, especially along one of the district's streams. We identified a total of 62 M. bovis genotypes. Identical genetic profiles were isolated from both neighboring and non-neighburing herds. The 10 most frequent genotypes, accounting for 82% of M. bovis isolates, showed geographic specificities in that they tended to cluster in specific spatial niches. The landscape structure of these niches-i.e. steep slopes, rocky ridges, meadows and streams-is likely to have had a significant influence on the distribution of TB among livestock in Caronia. Higher concentrations of TB were observed along streams and in open meadows, while rocky ridges and slopes appeared to have hampered the spread of TB. Discussion: The geographical distribution of TB cases among livestock in Caronia is consistent with several epidemiological scenarios (e.g., high density of infected herds along the streams or in hilly plateau where livestock share pastures). Landscape structure is likely to play an important role in the transmission and persistence of M. bovis infection across the district. Additional potential risk factors, such as livestock trading and extensive breeding methods, are also discussed. Our results will contribute to the improvement of surveillance, control and eradication activities of TB in Sicily by the implementation of ad hoc TB control measures, especially in farms located along streams, sharing common pastures or with mixed animal species.

Mycobacterium bovis Tuberculosis in Two Goat Farms in Multi-Host Ecosystems in Sicily (Italy): Epidemiological, Diagnostic, and Regulatory Considerations.

Mycobacterium bovis (M. bovis) is the causative agent of animal tuberculosis (bTB), infecting and causing disease in several animal species. In areas where there are complex interactions between reservoir hosts and susceptible species, the control of this pathogen is a challenge. The authors report two outbreaks of goat tuberculosis caused by M. bovis in multi-host ecosystems within two protected natural areas of Sicily, where TB is historically endemic. The first outbreak (Farm A) was identified after the incidental detection at the slaughterhouse of TB-like lesions in goat viscera ready to be disposed. Single intradermal cervical tuberculin test (SICT) was performed in Farm A on 205 goats, resulting positive in 10 (4.9%). After slaughtering, six out of ten animals showed TB-like lesions, from which M. bovis spoligotype SB0841 was isolated. The typing did not reveal any epidemiological connection with the neighboring cattle, suggesting that free-ranging type of management exposed the affected goat livestock or wildlife infected with other strains. The second outbreak (Farm B) was detected in a mixed farm (bovine, caprine, and ovine), where relapsing outbreaks of TB in cattle were registered in the previous years after performing the SICT in cohabiting goats. SICT resulted positive in 6/153 (3.9%), and two animals showed bTB-like lesions. No mycobacteria were cultured, and the final diagnosis of TB was achieved by histopathology and immunohistochemistry. The reported outbreaks highlight the importance of assessing the epidemiological, diagnostic, and regulatory critical issue, which is fundamental to optimizing the strategies of eradicating TB in the endemic multi-host ecosystem described.

Leptospira interrogans Serogroup Pomona in a Dairy Cattle Farm in a Multi-Host Zootechnical System.

Bovine leptospirosis is an infectious zoonotic disease causing reproductive problems and economic losses in livestock. This work reports, for the first time in Sicily (South Italy), an outbreak of Leptospira interrogans serogroup Pomona that occurred in cattle farms within the Nebrodi Park and was mainly characterized by full-term abortion. Blood and urine samples were collected at different time points from animals of six different farms (Farms A-F) sharing the same grazing area. Research of antibodies against pathogenic Leptospira species in serum samples was carried out via Micro Agglutination Test (MAT). Urine samples were subjected to pathogen isolation and molecular analyses via TaqMan Real Time-PCR. Genotyping of Leptospira species was obtained by Multi-locus sequence typing. MAT detected antibodies against Leptospira interrogans serogroup Pomona in serum samples of all the farms. Pathogenic Leptospira spp. DNA and culture isolation was obtained from urine samples. Genotyping confirmed the excretion of L. interrogans serogroup Pomona. This study describes clinical manifestations, diagnostic implications and epidemiological characteristics of an outbreak in cattle due to L. interrogans Pomona in a protected multi-host area, where domestic and wild animals share the same habitat, suggesting a role of wild species in transmission and persistence of Pomona serogroup among cattle.

Development and evaluation of a multi-antigen serological assay for the intra-vitam diagnosis of Tuberculosis caused by Mycobacterium bovis in pigs.

Bovine Tuberculosis (bTB) is a chronic disease caused by Mycobacterium bovis, affecting cattle and other mammalian species, such as pigs. In the present work, we developed a novel multi-antigen assay (The TB-Luminex multiplex test) to diagnose bTB in pig sera. Moreover, we investigated the seroreactivity to the different antigens employed (MPB83, MPB70, CFP10 and ESAT6) and the possible correlation with bTB lesions distribution in the positive pigs. The serum samples were collected from 59 bTB positive pigs and 186 pigs reared in an officially Tuberculosis free area. Sera were processed according to an optimized protocol for the detection of antibodies by a multiantigen assay using Luminex technology. The positive group showed visible lesions with localized (54.2%) or generalized (45.8%) distribution. Culture confirmed the infection in 62.7% of the cases, and histopathology and intra-vitam assays were used as additional confirmatory tests. Within the set of antigens tested, the immunodominant was MPB83 (positive in 94.9% of the affected pigs), followed by CFP10, MPB70 and ESAT6 (positivity shown in 81.3%, 67.8% and 25.4% of the positive pigs tested, respectively). The best antigens combination was MPB83/CFP10, with a 96.6% sensitivity and 96.8% specificity. Overall, the test showed high sensitivity (98.3% and 86.4%) and specificity (96.2% and 97.8%), if sera were considered positive according to the positivity to a single antigen or at least two antigens, respectively. The TB-Luminex multiplex test results did not give significantly different outcomes according to lesions distribution. Given the present study results, the TB-Luminex multiplex test is a reliable test capable of detecting bTB in most infected pigs with good Se and Sp, regardless of the stage of the disease. In conclusion, multi-antigen tests can be used as individual tests and screening tools for domestic and wild suids within bTB eradication programs.

Retrieving Historical Cases of Aujeszky's Disease in Sicily (Italy): Report of a Natural Outbreak Affecting Sheep, Goats, Dogs, Cats and Foxes and Considerations on Critical Issues and Perspectives in Light of the Recent EU Regulation 429/2016.

Aujeszky's disease is caused by Suid alphaherpesvirus 1, and its main reservoir host is the pig. However, other species are also susceptible. Infection with this virus causes a severe neurological clinical picture named Aujeszky's disease, usually accompanied by itching and death a few days after the onset of symptoms. This study reports a multi-species outbreak of Aujeszky's disease that occurred in Sicily, which led to the death of 2 goats, 15 sheep, 2 dogs, 2 cats and 2 foxes. The diagnosis was made by culture, indirect immunofluorescence on brain samples and confirmed by biological test on rabbits. This study reports the first cases of Aujeszky's disease in Italy in cats, goat and sheep. The finding of Aujeszky's disease in several species in Sicily suggests a potential epizootic risk. In such areas where a multi-host system is recognised, an analysis of the risk factors should be carried out in order to develop targeted strategies for the control and eradication of the disease. The critical issues that hinder the control of Aujeszky's disease in the studied territory and perspectives for eradication in the light of EU regulation 429/2016 are also discussed.

Intra-vitam Diagnosis of Tuberculosis in Pigs: Concordance Between Interferon-Gamma Release Assay and Comparative Tuberculin Skin Test.

The role of pigs in the maintenance of bovine tuberculosis caused by Mycobacterium bovis has been demonstrated in many settings; however, the current control programs usually do not state any intra-vitam diagnostic procedure in this species, as for the cattle. Carcass inspection has shown to be insufficient to detect infection in swine; thus, the assessment of intradermal tuberculin test and interferon-gamma release assay (IGRA) in this species is mandatory. The current study compares the performances of the single intradermal comparative cervical tuberculin (SICCT) test and IGRA. A total of 628 Nebrodi Black pigs raised in free-roaming farms were subjected to the two tests simultaneously. Besides, 124 animals underwent postmortem examination for the detection of tuberculous lesions and isolation of mycobacteria from target organs. The two tests showed a concordance of 94.42% with a Cohen's k coefficient of 0.786 and McNemar chi-square of 4.83 (P = 0.03). Slightly lower levels of concordance (90.32%) between SICCT and IGRA were obtained in the group of 124 animals, with a Cohen's k = 0.797 and McNemar chi-squared value of 0.69 with a non-significant P = 0.41. Moreover, the results showed how IGRA tends to result positive in higher rates, mostly when non-tuberculous mycobacteria (NTM) were isolated, suggesting a possible impairment of specificity in the event of coinfections in the swine. In conclusion, the results obtained support the possibility of the strategic use of IGRA or SICCT in combination or alternatively one to the other, particularly IGRA which showed lower specificity but has evident advantages over SICCT.

Genotype diversity and distribution of Mycobacterium bovis from livestock in a small, high-risk area in northeastern Sicily, Italy.

Bovine tuberculosis (bTB) caused by Mycobacterium bovis is an important re-emerging disease affecting livestock, wildlife and humans. Epidemiological studies are crucial to identifying the source of bTB infection, and its transmission dynamics and host preference, and thus to the implementation of effective strategies to contain it. In this study, we typed M. bovis isolates from livestock, and investigated their genetic diversity and distribution. A total of 204 M. bovis isolates were collected from cattle (n = 164) and Sicilian black pigs (n = 40) reared in a limited area of the province of Messina, northeastern Sicily, an area that had previously been identified as having the highest incidence of bTB in livestock on the island. All M. bovis isolates were typed by both spoligotyping and 12-loci MIRU-VNTR analysis. Results from both methods were then combined in order to improve the discriminatory power of M. bovis typing. We identified 73 combined genetic profiles. Thirty-five point six percent of the profiles were common to at least two animals, whereas 64.4% of profiles occurred in only one animal. A number of genetic profiles were predominant in either cattle or black pigs. We identified common genetic patterns in M. bovis isolates originating not only from neighboring districts, but also from non-neighboring districts. Our findings suggest that bTB is widespread in our setting, and is caused by a large number of genetically diverse M. bovis strains. The ecology and farming practices characteristic of the area may explain the substantial M. bovis heterogeneity observed, and could represent obstacles to bTB eradication.