Diagnostic performance of a rapid immunochromatographic test for the simultaneous detection of antibodies to Theileria equi and Babesia caballi in horses and donkeys

BACKGROUND

Equine piroplasmosis is caused by two tick-borne protozoan parasites, Theileria equi and Babesia caballi,, which are clinically relevant in susceptible horses, donkeys, and mules. Moreover, equine piroplasmosis significantly constrains international trading and equestrian events. Rapidly diagnosing both parasites in carrier animals is essential for implementing effective control measures. Here, a rapid immunochromatographic test for the simultaneous detection of antibodies to T. equi and B. caballi was evaluated using samples from horses and donkeys collected in Greece, Israel, and Italy. The results were compared with an improved competitive enzyme-linked immunosorbent assay (cELISA) for detecting antibodies to both parasites using the same panel of samples.

METHODS

Blood samples were collected from 255 horses and donkeys. The panel consisted of 129 horses sampled at four locations in northern Greece, 105 donkeys sampled at four locations in Sicily, and 21 horses sampled at two locations in Israel. The rapid test and the cELISA were performed according to the manufacturer's instructions, and the results were subjected to a statistical analysis to determine the sensitivity and specificity of both tests and their association.

RESULTS

The immunochromatographic test provided a result within 15 min and can be performed in the field, detecting both pathogens simultaneously. The overall coincidence rate between the rapid test and the cELISA for detecting antibodies against T. equi was 93% and 92.9% for B. caballi. The rapid test's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for T. equi were above 91.5%. Sixteen samples were positive for both parasites in the rapid test and eight in the cELISA. Either test had no significant association between T. equi and B. caballi detection. The detection rates of both parasites were significantly higher in Italy than in Greece or Israel and in donkeys than in horses. The agreement for T. equi between the results of both tests was high in Greece (93.8%) and Italy (95.2%) and moderate in Israel (76.2%). For B. caballi, the specificity and NPV of the rapid test were high (94.2% and 98.3%, respectively), although the sensitivity and PPV were moderate (69.2% and 39.1%, respectively) due to the small sample size. However, for B. caballi, the sensitivity was higher with the rapid test.

CONCLUSIONS

The rapid test detected T. equi and B. caballi simultaneously in the field, potentially replacing laborious cELISA testing and is recommended for import/export purposes. The test can also be helpful for the differential diagnosis of clinical cases, since seropositivity may rule out equine piroplasmosis since it does not indicate current or active infection.

Persistence of clock gene expression in peripheral blood in dogs maintained under different photoperiod schedules

Dogs are the common pets adopted by humans, and their circadian behavior and physiology are influenced by human habits. In many families, there is a change of lifestyle with respect to the natural daylight (NDL) cycle. Exposure to constant light disrupts some central and peripheral circadian rhythms. The aim of the present study was to improve the knowledge about the circadian changes of clock components in the peripheral blood in dogs housed under NDL and constant light (LL) conditions. Blood samples were collected on five female Beagle dogs (2 years old, 14 ± 0.5 kg) every 4 hours for a 24-hour period during an NDL (Sunrise 05:05 h - Sunset 20:55  h) and 24-hour period of constant light (LL). Blood samples were stored in a PAX gene Blood RNA Tube, real-time RT-quantitative polymerase chain reaction was performed to determine Clock, Per1-3, and Cry1-2 gene expression. During the NDL, all genes investigated showed robust diurnal daily rhythmicity. During the constant light, only Clock maintained its daily rhythmicity. Clock acrophase was observed close to sunrise (ZT 0) and was statistically different from the other clock genes except for Per3. Per3 daily oscillations were not statistically significant. No differences were observed among the clock genes tested in the amplitude and robustness values. Our results can be considered preliminary data to provide new insights into the adaptation mechanism of the canine peripheral circadian clock. The persistence of Clock gene expression during the LL indicated the presence of an endogenously generated signal in blood. Because peripheral blood is an easily accessible sample in dogs, the analysis of clock gene expression in this tissue could be useful to investigate the adaptive capacity of this species housed in different environmental conditions linked to the owner's lifestyle.

Molecular epidemiology of canine parvovirus type 2 in Sicily, southern Italy: A geographical island, an epidemiological continuum

Since it emerged as a major dog pathogen, canine parvovirus type 2 (CPV-2) has featured a remarkable genetic and phenotypic heterogeneity, whose biological, epidemiological, and clinical impact is still debated. The continuous monitoring of this pathogen is thus of pivotal importance. In the present study, the molecular epidemiology of CPV-2 in Sicily, southern Italy, has been updated by analysing 215 nearly complete sequences of the capsid protein VP2, obtained from rectal swabs/faeces or tissue samples collected between 2019 and 2022 from 346 dogs with suspected infectious gastrointestinal disease. The presence of the original CPV-2 type (4%) and CPV-2a (9%), CPV-2b (18%), or CPV-2c (69%) variants was documented. Over the years, we observed a decrease in the frequency of CPV-2a/-2b and a rapid increase of CPV-2c frequency, with a progressive replacement of the European lineage of CPV-2c by the Asian lineage. The observed scenario, besides confirming epidemiological relevance of CPV-2, highlights the occurrence of antigenic variant shifts over time, with a trend toward the replacement of CPV-2a, CPV-2b, and the European lineage of CPV-2c by the emerging Asian CPV-2c lineage. The comparison with other Italian and international sequences suggests the occurrence of viral exchange with other Italian regions and different countries, although the directionality of such viral flows could not be often established with confidence. In several instances, potential CPV-2 introductions led to epidemiological dead ends. However, major, long-lasting clades were also identified, supporting successful infection establishment, local spreading, and evolution. These results, besides demonstrating the need for implementing more effective control measures to prevent viral introductions and minimize circulation, stress the relevance of routine monitoring activities as the only tool to effectively understand CPV-2 epidemiology and evolution, and develop adequate countermeasures.

A Canine Leptospirosis Clinical Case Due to Leptospira interrogans (Serogroup Icterohaemorrhagiae) in a Dog Kennel in Castelvetrano (Western Sicily, South Italy)

Leptospirosis is a worldwide widespread zoonosis caused by Leptospira genus. We report an acute leptospirosis case in a puppy housed at a municipal kennel and the subsequent diagnostic investigations carried out on all dogs housed in the kennel. Laboratory investigation included mainly a microagglutination test, real-time PCR, and multi-locus sequence typing (MLST) for Leptospira genus. Other agents of infection were excluded. The puppy resulted positive for Leptospira interrogans Icterohaemorrhagiae both with serological and molecular assays. All of the other 66 dogs in the kennel underwent clinical and laboratory investigations twice, 15 days apart. No other dog showed leptospirosis clinical signs. At the first sampling, eight dogs (12%) showed antibodies against Leptospira interrogans serogroup Icterohaemorragiae serovar Copenhageni. Real-time PCR on urine samples of seropositive dogs detected Leptospira spp. DNA in one sample, then identified as Leptospira interrogans serogroup Icterohaemorragiae by MLST. Fifteen days after, four of the previous seropositive dogs still showed antibodies against Leptospira spp. All urine samples collected from seropositive dogs were negative at real-time PCR. The study allowed the early confirmation of a Leptospirosis case and the identification of at least one asymptomatic carrier of pathogenic Leptospira spp. The prompt activation of all appropriate management measures allowed limiting and extinguishing the infection.

Interplay Among the Daily Rhythm of the Thyroid Hormones, Uncoupling Protein 1 and the Clock Gene Per2 in Horses

During husbandry, domestic animals are exposed to many factors that can influence their circadian physiology organization leading to an increase in animals' discomfort. Thermal homeostasis is at the basis of animal wellness, the aim of the present study was to investigate the daily fluctuation of serum concentrations of 3,5,3'-triiodothyronine (T3) and thyroxine (T4) in association with the daily fluctuation of uncoupling protein 1 (UCP1) and clock gene Per2 in healthy horses housed in individual box, to improve the knowledge on this matter. Seven clinically healthy female Italian Saddle horses (8-10 years old, 510 ± 32 kg), were housed in individual boxes under natural photoperiod and environmental temperature and humidity. Blood samples were collected at 4-hour intervals over a 48-hour period, for the assessment of T3, T4, UCP1, and clock gene Per2. The application of two-way analysis of variance (ANOVA) on raw data showed a statistically significant effect of time of day on all studied parameters. A robust daily rhythm of T3, T4, and Per2 was observed. T3 showed a diurnal rhythm, with the acrophase at about 5 hours after sunrise, T4 acrophase was observed in the middle of the scotophase, Per2 acrophase was observed close to sunrise. In conclusion, we can claim that in horses kept under natural environmental conditions and not subjected to thermal stress, there is a daily rhythm of thyroid hormones associated with a daily rhythm of Per2 expression in the peripheral blood, and UCP1 remained constant during the two days.

Biomolecular Analysis of Canine Distemper Virus Strains in Two Domestic Ferrets (Mustela putorius furo)

Canine distemper is a contagious and severe systemic viral disease that affects domestic and wild carnivores worldwide. In this study, two adult female ferrets (Mustela putorius furo) were evaluated for cutaneous lesions. Scab, fur, and swab samples from the external auditory canal, cutaneous lesions, and scrapings were analyzed. Canine distemper virus (CDV)-positive samples underwent RT-PCR/RFLP with the restriction enzyme PsiI, and the hemagglutinin gene sequence was obtained. According to the restriction enzyme and sequence analyses, the viral strains were typed as CDV field strains that are included within the Europe lineage and distinct from those including vaccinal CDV strains. The sequence analysis showed the highest nucleotide identity rates in older Europe lineage CDV strains collected from dogs and a fox in Europe. This study is the first to report on CDV infection in ferrets in southern Italy and contributes to the current knowledge about natural CDV infection in this species. In conclusion, vaccination remains crucial for preventing the disease and counteracting cross-species infection. Molecular biology techniques can enable the monitoring of susceptible wild animals by ensuring the active surveillance of CDV spread.

Epizootic Hemorrhagic Disease Virus Serotype 8, Italy, 2022

We describe the detection of epizootic hemorrhagic disease virus (EHDV) serotype 8 in cattle farms in Sardinia and Sicily in October-November 2022. The virus has a direct origin in North Africa; its genome is identical (>99.9% nucleotide sequence identity) to EHDV serotype 8 strains detected in Tunisia in 2021.

A Review on the Immunological Response against Trypanosoma cruzi

Chagas disease is a chronic systemic infection transmitted by Trypanosoma cruzi. Its life cycle consists of different stages in vector insects and host mammals. Trypanosoma cruzi strains cause different clinical manifestations of Chagas disease alongside geographic differences in morbidity and mortality. Natural killer cells provide the cytokine interferon-gamma in the initial phases of T. cruzi infection. Phagocytes secrete cytokines that promote inflammation and activation of other cells involved in defence. Dendritic cells, monocytes and macrophages modulate the adaptive immune response, and B lymphocytes activate an effective humoral immune response to T. cruzi. This review focuses on the main immune mechanisms acting during T. cruzi infection, on the strategies activated by the pathogen against the host cells, on the processes involved in inflammasome and virulence factors and on the new strategies for preventing, controlling and treating this disease.

A SARS-CoV-2 full genome sequence of the B.1.1 lineage sheds light on viral evolution in Sicily in late 2020

To investigate the influence of geographic constrains to mobility on SARS-CoV-2 circulation before the advent of vaccination, we recently characterized the occurrence in Sicily of viral lineages in the second pandemic wave (September to December 2020). Our data revealed wide prevalence of the then widespread through Europe B.1.177 variant, although some viral samples could not be classified with the limited Sanger sequencing tools used. A particularly interesting sample could not be fitted to a major variant then circulating in Europe and has been subjected here to full genome sequencing in an attempt to clarify its origin, lineage and relations with the seven full genome sequences deposited for that period in Sicily, hoping to provide clues on viral evolution. The obtained genome is unique (not present in databases). It hosts 20 single-base substitutions relative to the original Wuhan-Hu-1 sequence, 8 of them synonymous and the other 12 encoding 11 amino acid substitutions, all of them already reported one by one. They include four highly prevalent substitutions, NSP12:P323L, S:D614G, and N:R203K/G204R; the much less prevalent S:G181V, ORF3a:G49V and N:R209I changes; and the very rare mutations NSP3:L761I, NSP6:S106F, NSP8:S41F and NSP14:Y447H. GISAID labeled this genome as B.1.1 lineage, a lineage that appeared early on in the pandemic. Phylogenetic analysis also confirmed this lineage diagnosis. Comparison with the seven genome sequences deposited in late 2020 from Sicily revealed branching leading to B.1.177 in one branch and to Alpha in the other branch, and suggested a local origin for the S:G118V mutation.

Persistence of DNA from canine parvovirus modified-live virus in canine tissues

Canine parvovirus (CPV-2) modified-live virus vaccine strain can replicate in lymphoid tissues and intestinal mucosa after administration, being shed through canine faeces. Detection of vaccine strains has been reported in the bloodstream and faeces, potentially interfering with molecular diagnostic tests. The persistence of these strains in canine tissues has not yet been described. With this aim, canine tissues were tested during a molecular survey to screen for the presence of canine enteric viruses. Tissue samples from 165 dead dogs were tested by a conventional PCR assay. Positive samples and five commercial vaccines were subjected to sequence analysis. Vaccinal strains were detected and virus load was measured by using a set of real-time PCR assays using minor-groove binder (MGB) probes. Seventy-five dogs (45.4%) tested positive for CPV-2. Strains from 70 dogs were characterised as field variants. The presence of CPV sequences of vaccine origin was observed in the spleen, intestine, and mesenteric lymph nodes of five young dogs. Vaccinal strains were detected from 12 to 24 days after the last vaccine administration. Viral loads comprised between 6.3 × 10² and 9.95 × 10⁴ DNA copies/10 µl of template. This study confirms that CPV vaccinal strains can be detected in canine tissues after vaccination, so post-mortem diagnosis of CPV infection needs further molecular analyses to assess the viral type (vaccine or field strains). The present study updates the current information on the persistence of CPV vaccine strains in canine tissues and their possible interference with molecular assays.

Study on the Canine Adenovirus Type 1 (CAdV-1) Infection in Domestic Dogs in Southern Italy

Canine adenovirus type 1 (CAdV-1) is the causative agent of a systemic and potentially fatal viral disease of domestic and wild canids. In Italy, CAdV-1 infection has also been occasionally described in dogs, but information on the epidemiology and its genomic features is still limited. A study was conducted on 291 dogs suspected of infectious gastrointestinal disease. Samples collected from dogs in southern Italy between 2017 and 2020 were analyzed. Virological and histopathological assays were carried out. The presence of CAdVs and other canine viral enteropathogens was investigated, and sequence and phylogenetic analyses were performed. CAdV-1 was detected in six (2.1%) dead stray dogs alone or in mixed infections with other viruses. Gross lesions and histopathological findings referred to CAdV infection were observed, also involving the central nervous system tissues. All inoculated samples were successfully isolated. Sequence analysis evidenced divergences with the circulating strains previously described in Italy and a closer relation with older CAdV-1 strains collected from other countries, suggesting a genetic heterogeneity of CAdV-1 in Italy. The evidence of the circulation of CAdV-1 and its genomic features allows us to have more in-depth knowledge of the epidemiology and evolution of the CAdV-1 genomic variants.

Pilot Investigation of SARS-CoV-2 Variants in the Island of Sicily Prior to and in the Second Wave of the COVID-19 Pandemic

After 2 years of the COVID-19 pandemic, we continue to face vital challenges stemming from SARS-CoV-2 variation, causing changes in disease transmission and severity, viral adaptation to animal hosts, and antibody/vaccine evasion. Since the monitoring, characterization, and cataloging of viral variants are important and the existing information on this was scant for Sicily, this pilot study explored viral variants circulation on this island before and in the growth phase of the second wave of COVID-19 (September and October 2020), and in the downslope of that wave (early December 2020) through sequence analysis of 54 SARS-CoV-2-positive samples. The samples were nasopharyngeal swabs collected from Sicilian residents by a state-run one-health surveillance laboratory in Palermo. Variant characterization was based on RT-PCR amplification and sequencing of four regions of the viral genome. The B.1.177 variant was the most prevalent one, strongly predominating before the second wave and also as the wave downsized, although its relative prevalence decreased as other viral variants, particularly B.1.160, contributed to virus circulation. The occurrence of the B.1.160 variant may have been driven by the spread of that variant in continental Europe and by the relaxation of travel restrictions in the summer of 2020. No novel variants were identified. As sequencing of the entire viral genome in Sicily for the period covered here was restricted to seven deposited viral genome sequences, our results shed some light on SARS-CoV-2 variant circulation during that wave in this insular region of Italy which combines its partial insular isolation with being a major entry point for the African immigration.

Leptospira in Slaughtered Fattening Pigs in Southern Italy: Serological Survey and Molecular Typing

Simple Summary

In this study, serological and molecular assays in 55 pigs in Sicily were conducted in order to investigate Leptospira spp. prevalence and to carry out strain characterization. A seropositivity rate of 16.4% was determined; 3.64% of kidney samples tested positive for pathogenic Leptospiral DNA. Obtained data showed that Leptospira infection is common among pigs in southern Italy, confirming the importance of Leptospiral infection in pigs and reaffirming the potential role of these animals as a source of infection for humans (occupational risk) and other animals. Our study delivers a comprehensive overview based on up-to-date data to deepen the knowledge of swine leptospiral infections, characterize new potential emerging strains, and reinforce control measures able to reduce the infection risk in swine herds.

Abstract

Leptospirosis is a re-emerging zoonosis of worldwide significance; a wide spectrum of wild and domestic animal species act as natural or accidental hosts. Swine can act as maintenance or accidental hosts of pathogenic Leptospira spp. This study aimed at investigation of Leptospira spp. prevalence and diversity in slaughtered pigs in southern Italy (Sicily). In total, 55 samples of kidneys and blood were collected. Microscopic agglutination test and real-time PCR were performed to detect pathogenic and intermediately pathogenic Leptospira. Partial rpoB gene sequencing and multi-locus sequence typing (MLST) were performed to characterize Leptospira species. The analysis showed a seropositivity rate of 16.4%, with Australis representing the most frequently identified serogroup (63.64%); Pomona and Sejroe were detected with a prevalence of 27.27% and 9.09%, respectively. Pathogenic Leptospiral DNA was detected in 2 kidney samples (3.64%). Leptospira were identified through MLST as L. borgpetersenii serovar Tarassovi (serogroup Tarassovi). Obtained data confirmed the presence of Leptospira infection among pigs in southern Italy, suggesting that management of these animals may be considered an occupational risk for humans.

Silk-based matrices and c-Kit positive cardiac progenitor cells for a cellularized silk fibroin scaffold: study of an in vivo model

The production of a cellularized silk fibroin scaffold is very difficult because it is actually impossible to differentiate cells into a well-organized cardiac tissue. Without vascularization, not only do cell masses fail to grow, but they may also exhibit an area of necrosis, indicating a lack of oxygen and nutrients. In the present study, we used the so-called tyrosine protein kinase kit (c-kit)-positive cardiac progenitor cells (CPCs) to generate cardiac cellularized silk fibroin scaffolds, multipotent cells isolated from the adult heart to date that can show some degree of differentiation toward the cardiac phenotype. To test their ability to differentiate into the cardiac phenotype in vivo as well, CPC and collagen organoid-like masses were implanted into nude mice and their behavior observed. Since the three-dimensional structure of cardiac tissue can be preserved by scaffolds, we prepared in parallel different silk fibroin scaffolds with three different geometries and tested their behavior in three different models of immunosuppressed animals. Unfortunately, CPC cellularized silk fibroin scaffolds cannot be used in vivo. CPCs implanted alone or in collagen type I gel were destroyed by CD3+ lymphocytes’ aggregates, whereas the porous and partially oriented scaffolds elicited a consistent foreign body response characterized by giant cells. Only the electrospun meshes were resistant to the foreign body reaction. In conclusion, c-kit-positive CPCs, although expressing a good level of cardiac differentiation markers in vitro with or without fibroin meshes, are not suitable for an in vivo model of cardiac organoids because they are degraded by a T-cell-mediated immune response. Even scaffolds, which may preserve the survival of these cells in vivo, also induced a host response. However, among the tested scaffolds, the electrospun meshes (F-scaffold) induced a lower response compared to all the other tested structures.

Antimicrobial Resistance (AMR) of Bacteria Isolated from Dogs with Canine Parvovirus (CPV) Infection: The Need for a Rational Use of Antibiotics in Companion Animal Health

Canine parvovirus type 2 (CPV-2) represents a major viral threat to dogs. Considering the potential effects of pets on antimicrobial resistance, information on the CPV and associated bacterial co-infections is limited. The aim of this study was to analyze the antimicrobial susceptibility and multidrug-resistance profiles of bacterial species from tissue samples of dogs with canine parvovirus infection. A set of PCR assays and sequence analyses was used for the detection and the molecular characterization of the CPV strains and other enteric viruses. Bacterial isolation, the determination of antimicrobial susceptibility via the disk diffusion method, and the determination of the minimum inhibitory concentration were performed. The detection of β-lactamase genes and toxin genes for specific bacteria was also carried out. CPV infection was confirmed in 23 dogs. Forty-three bacterial strains were isolated and all showed phenotypic resistance. Seventeen multidrug-resistant bacteria and bacteria with high resistance to third- and fourth-generation cephalosporins and metronidazole were detected. Almost 50% of the isolated Enterobacteriaceae were positive for at least one β-lactamase gene, with the majority carrying more genes as well. The evidence for multi-resistant bacteria with the potential for intra- or cross-species transmission should be further considered in a One Health approach.

Peste des petits ruminants in Nigeria: identification and variations of lineage II and lineage IV in sheep and goats

Peste des petits ruminants virus (PPRV) is the aetiologic agent of Peste des petits ruminants (PPR), an important viral disease of sheep and goats. PPR is endemic in Nigeria and leads to social and economic losses. The objective of this study was to determine the prevalence of PPR infection and genetically characterize PPRV strains obtained from sheep and goats in three States of Southeast Nigeria. A total of 285 nasal swab samples collected in 2017‑2018 were processed for PPRV genome detection by RT‑PCR. Sixty‑five (22.81%) of the samples were positive for PPRV. Sequence and phylogenetic analyses revealed that the PPRV belonged to lineages II (11/38, 28.9%) and IV (27/38, 71.1%). The N gene fragment sequence showed a 99.77%‑100% and 99.98%‑100% identity among the strains of lineages II and IV, respectively. Fourteen amino acid substitutions, previously unreported in PPRV strains from Nigeria, were recorded. This study confirms the circulation of PPRV lineages II and IV in Southeast Nigeria, the dominance of strains belonging to lineage IV in recent years, and their close genetic relationship with those previously reported in other parts of Nigeria and neighboring countries.

Recent Advances on the Innate Immune Response to Coxiella burnetii

Coxiella burnetii is an obligate intracellular Gram-negative bacterium and the causative agent of a worldwide zoonosis known as Q fever. The pathogen invades monocytes and macrophages, replicating within acidic phagolysosomes and evading host defenses through different immune evasion strategies that are mainly associated with the structure of its lipopolysaccharide. The main transmission routes are aerosols and ingestion of fomites from infected animals. The innate immune system provides the first host defense against the microorganism, and it is crucial to direct the infection towards a self-limiting respiratory disease or the chronic form. This review reports the advances in understanding the mechanisms of innate immunity acting during C. burnetii infection and the strategies that pathogen put in place to infect the host cells and to modify the expression of specific host cell genes in order to subvert cellular processes. The mechanisms through which different cell types with different genetic backgrounds are differently susceptible to C. burnetii intracellular growth are discussed. The subsets of cytokines induced following C. burnetii infection as well as the pathogen influence on an inflammasome-mediated response are also described. Finally, we discuss the use of animal experimental systems for studying the innate immune response against C. burnetii and discovering novel methods for prevention and treatment of disease in humans and livestock.

Hepatitis E Virus seroprevalence among cows in a rural area of southern Italy

Hepatitis E virus (HEV) is considered to be an emerging zoonotic disease, which causes numerous cases of hepatitis and deaths worldwide each year. Pigs are a host reservoir of HEV, but numerous other wild and domestic species can be infected. The aim of this study was to carry out serological screening of anti-HEV antibodies in cattle in the Sicily region (Southern Italy). Between April and December 2018, 231 serum samples were collected from cows and analysed with enzyme-linked immunosorbent assay (ELISA), for detection of HEV antibodies (IgG). The overall prevalence of anti-HEV antibodies was 36.36% (84/231; 95% CI 30-43). There were statistically significant differences in the HEV seroprevalence in animals of different ages (<11 months: 11.41%; >12 months: 39.30%; >24 months: 54.10%) (P<0.05). No statistically significant differences were detected between genders (31.37% in male and 37.38% in female) (P >0.05). This study shows that further investigation of HEV in cattle is required to understand better the epidemiology in farm animals and the potential zoonotic risks for humans. This is the first report of HEV seroprevalence for cows in Italy, which provides baseline data for further studies and for control of HEV infection in cattle.

First neuroinvasive human case of West Nile Disease in Southern Italy: Results of the 'One Health' approach

Background

West Nile Disease (WND) is a zoonotic mosquito‐borne infection involving viral pathogens, human and animal hosts, vectors and environment. Cooperation among medical, veterinary and entomological fields has been promoted by the Italian Public Health Authorities, and an integrated West Nile Virus (WNV) Surveillance Plan has been in force in Italy since 2016 to prevent the transmission risk of WND to humans through an early detection of viral circulation by animal and entomological surveillance. This managing model is unique in Europe.

Objectives

This survey aimed at presenting the ‘One Health’ approach applied in 2016 to the first autochthonous human case of West Nile Neuroinvasive Disease (WNND) in Sicily (Southern Italy).

Methods

Serological (anti‐WNV IgM and IgG ELISA, anti‐WNV neutralizing antibodies) and molecular tests were conducted on blood, liquor and urine of a 38‐year‐old man with encephalitis and meningitis. Overall, 2704 adult culicides from 160 mosquito catches were morphologically identified. Female mosquitoes were analysed in pools for WNV RNA detection. Serological (anti‐WNV IgM and IgG ELISA) and molecular analyses for WNV were carried out in 11 horses, 271 chickens and two dogs sampled in farms around the man's residence.

Results and conclusions

WNND was confirmed by serological analysis on patient's liquor and serum. Collected mosquito species included Culex pipiens (93.56%, CI_95% 92.64%–94.49%), Aedes albopictus (5.25%, CI_95% 4.41%–6.09%), Culex hortensis (0.59%, CI_95% 0.30%–0.88%), Culiseta longiareolata (0.55%, CI_95% 0.27%–0.83%) and Anopheles maculipennis s.l. (0.04%, CI_95% –0.04% to 0.11%). Mosquito pools were negative for WNV RNA. Two dogs (100%) and two horses (18.18%, CI_95% –4.61 to 40.97%) resulted positive for anti‐WNV specific antibodies.

The ‘One Health’ approach allowed to report the first human neuroinvasive WND in Sicily and to confirm the local circulation of WNV in animals of the same area where the clinical case occurred, defining the autochthonous origin of the infection.

Detection and Molecular Characterization of Two Gammaherpesviruses from Pantesco Breed Donkeys during an Outbreak of Mild Respiratory Disease

Equid and asinine gammaherpesviruses (GHVs; genus Percavirus) are members of the Herpesviridae family. Though GHVs have been reported in horse populations, less studies are available on gammaherpesviral infections in donkeys. This study reports the co-infection with two GHVs in Pantesco breed donkeys, an endangered Italian donkey breed. Samples (n = 124) were collected on a breeding farm in Southern Italy from 40 donkeys, some of which were healthy or presented erosive tongue lesions and/or mild respiratory signs. Samples were analysed by using a set of nested PCRs targeting the DNA polymerase, glycoprotein B, and DNA-packaging protein genes, and sequence and phylogenetic analyses were performed. Twenty-nine donkeys (72.5%) tested positive, and the presence of Equid gammaherpesvirus 7 and asinine herpesvirus 5 was evidenced. In 11 animals, we found evidence for co-infection with viruses from the two species. Virions with herpesvirus-like morphology were observed by electron microscopic examination, and viruses were successfully isolated in RK-13-KY cell monolayers. The histological evaluation of tongue lesions revealed moderate lympho-granulocytic infiltrates and rare eosinophilic inclusions. The detection of GHVs in this endangered asinine breed suggests the need long-life monitoring within conservation programs and reinforces the need for further investigations of GHV’s pathogenetic role in asinine species.

The Effect of a 7 Year-Long Cryopreservation on Stemness Features of Canine Adipose-Derived Mesenchymal Stem Cells (cAD-MSC)

Mesenchymal stem cells (MSCs) are used in therapy in animal models and veterinary medicine, due to their capacity of inducing tissue regeneration and immunomodulation. Their clinical application requires a ready off-the-shelf amount of viable therapeutics doses. For this purpose, it is useful to cryopreserve MSCs to gain a ready and controlled source of abundant autologous stem cells. We evaluated the effect of 7 years cryopreservation using 10% dimethyl sulfoxide (DMSO) with different fetal bovine serum (FBS) concentrations (from 10 to 90%) on different passages of MSCs isolated from canine adipose tissue (cAD-MSCs). The study aimed to evaluate the most adequate cell passage and FBS percentage for the long-term cryopreservation of cells by maintaining the stemness features. Phenotype morphology, cell viability, osteogenic and adipogenic differentiation potentials, proliferative potential and expression of pluripotency markers were analyzed in thawed cells and compared with fresh ones. We demonstrated that cells cryopreserved with at least 80% FBS maintain unaltered the stemness characteristics of the freshly isolated cells. In particular, cells of P0-P1 passages have to be expanded in vitro and subsequently cryopreserved and cells of P2-P4 passages should be considered in the studies on therapeutic application and in vitro study of cAD-MSCs.

Clock genes determination in whole blood in goats housed under a long light cycle

An innate 24 h circadian clock drives various behavioral processes via expression of clock genes that regulate circadian rhythmicity and temporal signals. Elucidating the gene expression in goats may contribute to improving the knowledge of the regulation of circadian rhythms in this species. Five nonpregnant and nonlactating Maltese goats with no evidence of disease were kept in an indoor pen under the natural long photoperiod (05:05-20:56 h) and natural environmental temperature (23°C and 60% RH). They were fed an Alfalfa hay and concentrate mixture provided twice a day; water was available ad libitum. Blood samples were collected every 4 h over a 48 h period into PAX gene Blood RNA Tubes and stored at -80°C until processing. Clock genes (Clock; Cry1; Cry2; Per2; Per3) were determined using real-time quantitative polymerase chain reaction. During the experimental period, locomotor activity was monitored by an actigraphy-based data logger that records a digitally integrated measure of motor activity as a means to assess indices of discomfort during study and stability of the circadian rhythm. All of the tested genes showed daily rhythmicity in their expression in whole blood. Differences in their circadian parameters were observed. Mesor and amplitude were statistically different among the tested gene (Mesor: F_(4.30) = 205.30; p < .0001; amplitude: F_(4.30) = 104.80; p < .0001), with each gene showing its acrophase at a different time of day (F_(4.30) = 81.17; p < .0001), and differences were observed between the two days of monitoring (F_(1.30) = 10.25; p = .003). The application of two-way analysis of variance (ANOVA) on robustness of rhythm values did not show statistical differences among the tested genes (F_(4.30) = 1.83; p = .14) and between the two days of monitoring (F_(1.30) = 1.16; p = .28). Locomotor activity data recording were in accordance with the data reported in literature, indicating the absence of discomfort or alteration of circadian rhythms during the experimental period. Our results support the presence of a cyclic transcription of clock genes in whole blood of healthy goats housed under a long light natural photoperiod and natural environmental conditions.

Serological and Molecular Evidence of Bartonella henselae in Stray Cats from Southern Italy

Bartonella henselae is a slow growing and facultative intracellular pathogen mainly transmitted by arthropod vectors adapted to domestic and wild mammalian reservoir hosts. Since cats are the major source of the B. henselae infection, this study aimed to evaluate the seroprevalence and the DNA presence in randomly sampled stray cats. Blood samples of 429 cats were collected from shelter of Palermo (Southern Italy) and sera and whole blood were analyzed for the presence of antibodies against B. henselae by indirect immunofluorescence assay (IFA) and by real-time polymerase chain reaction (PCR), respectively. Two hundred and three sera (47.3%) were positive to IFA and 148 blood samples (34.5%) to real-time PCR. Based on serological results, the evaluation of the potential risk factors (sex, age, coat color) was carried out. The multivariate analysis indicated that cats more than 12 months old were more likely to be seropositive to B. henselae than cats <12 months. These data will add useful information to the understanding of the spread of B. henselae in stray cats in Southern Italy.

Current status and risk factors of canine parvovirus type 2 in North Central Nigeria

Since its emergence in Nigeria, canine parvovirus type 2 (CPV-2) infection has posed problems to dog breeding and requires constant awareness and monitoring. In this study, the status, the assessment of extrinsic risk factors of parvoviral infection in dog kennels in North Central Nigeria, and isolation of the CPV-2 were carried out. Potential risk factors were considered during sampling: age, breed, sex, location, vaccination and health status, using well-structured questionnaires on dog owners with experience of CPV-2 infection. There was high prevalence which depended on age, breed, location, clinical status of the dog while vaccination status of the dogs did not influence the prevalence. CPV-2 vaccination compliance by the breeders and management system of the kennels were also observed as risk factors. Isolation of CPV-2a and -2c strains from Nigeria for further study has been reported. The spread of CPV-2 in Nigeria is increasing, hence needs for continual epidemiological monitoring and review.

Molecular epidemiology of canine parvovirus type 2 in Italy from 1994 to 2017: recurrence of the CPV-2b variant

Background

Canine parvovirus type 2 (CPV-2) is the most important enteric virus infecting canids. It is a rapidly evolving virus; after its emergence in the 1970s, new antigenic variants (called CPV-2a, 2b and 2c) emerged and replaced the original antigenic type. The three antigenic variants are globally distributed with different frequencies and levels of genetic variability. This study focused on VP2 gene sequence analysis and the phylodynamics of CPV-2 which were detected in 123 dogs showing clinical signs of gastroenteritis collected in Italy from 1994 to 2017.

Results

For the most part, the sick dogs were young, and a third of them (32.5%) had been vaccinated. No statistical association was found between the CPV-2 antigenic variants, and sex, age, breed and vaccination status. Sequence analysis showed that all three antigenic types circulated in Italy; the CPV-2a type was the prominent genotype, followed by CPV-2c and CPV-2b, with notable differences regarding regional bases and significant fluctuations over time. Nucleotide sequence data showed high genetic heterogeneity with 67 nucleotide sequence types (ntSTs) identified, corresponding to 21 amino acid sequence types (aaSTs). The aaSTs and ntSTs obtained were distributed differently among the three CPV-2 antigenic variants: CPV-2a grouped 12/21 (57.1%) aaSTs and 41/67 (61.2%) ntSTs; CPV-2b grouped 5/21 (23.8%) aaSTs and 6/67 (8.9%) ntSTs, and CPV-2c grouped 4/21 (19.1%) aaSTs and 20/67 (29.9%) ntSTs. Canine parvovirus 2a was characterised by the highest genetic variability while CPV-2c was characterised by notable stability with a predominant amino acid profile during the entire sampling time. Canine parvovirus 2b re-emerged in recent years, showing a new and distinctive amino acid profile of the VP2 protein.

Conclusions

The findings of the present study provided new insights regarding the phylodynamics and evolution of CPV-2 in Italy, pointing out notable differences at the local level in the distribution of the CPV-2 variants and the selection of genetic subtypes. The evolution of CPV-2 has raised questions regarding the efficacy of vaccination; therefore, continuous monitoring regarding the evolution and spread of new CPV-2 variants should be a key aim of ongoing research.

Nearly full-length genome characterization of canine parvovirus strains circulating in Nigeria

Canine parvovirus type 2 (CPV‐2) emerged suddenly in the late 1970s as pathogen of dogs, causing a severe and often fatal gastroenteric disease. The original CPV‐2 was replaced by three antigenic variants, CPV‐2a, CPV‐2b and CPV‐2c, which to date have gained a worldwide distribution with different relative proportions. All previous studies conducted in Africa were based on partial VP2 gene sequences. The aim of this study was to provide a genome analysis to characterize the CPV strains collected in Nigeria, Africa. Rectal swab samples (n = 320) were collected in 2018 and tested by means of an immunochromatographic assay. Among the 144 positive samples, 59 were selected for further analyses using different molecular assays. The results revealed a high prevalence of CPV‐2c (91.5%) compared to the CPV‐2a variant (8.5%). The VP2 gene sequences showed a divergence from the strains analysed in 2010 in Nigeria and a closer connection with CPV strains of Asian origin. The non‐structural gene analysis evidenced amino acid changes never previously reported. The molecular analysis based on genomic sequences evidenced a geographical pattern of distribution of the analysed strains, suggesting a potential common evolutionary origin with CPV of Asian origin. This study represents the first CPV molecular characterization including all the encoding gene sequences conducted in the African continent and contributes to define the current geographical spread of the CPV variants worldwide.

Spreading of canine parvovirus type 2c mutants of Asian origin in southern Italy

Canine parvovirus type 2 (CPV‐2) emerged as dog pathogen in the late 1970s, causing severe and often fatal epizootics of gastroenteritis in the canine population worldwide. Although to date CPV‐2 is circulating in all continents, most of the current studies have analysed the amino acid changes accounted in the VP2 gene sequence, with limited information on virus introductions from other countries. The aim of this study was to analyse the genetic features of CPV‐2c strains currently spreading in Italy. Swabs and tissue samples were collected from dogs suspected of CPV infection. The nearly complete genome sequence from the CPV‐positive samples was obtained. The co‐circulation of two different but related CPV‐2c strains, with amino acid changes characteristic of CPV strains of Asian origin (NS1: 60V, 544F, 545F, 630P – NS2: 60V, 151N, 152V ‐ VP2: 5A/G, 267Y, 297A, 324I, 370R), were observed. The phylogenetic analyses inferred from the NS1 and VP2 gene sequences confirmed the relationship with Asian CPV‐2c strains. This study reports the spread of novel CPV‐2c mutants in Italy and supports further studies to evaluate the coexistence of genetically divergent CPV strains in the same geographical environment.

A case of bovine trypanosomiasis caused by Trypanosoma theileri in Sicily, Italy

Despite some researchers reporting clinical signs in cattle associated with Trypanosoma theileri, its role as a pathogen is still unclear. We describe here the isolation of Trypanosoma theileri during a routine laboratory investigation. Mature and immature vital parasitic forms were observed within hematopoietic cell cultures from the bone marrow of one cow for monocyte isolation. The animal was submitted to clinical examination and blood sample counting (CBC). Postmortem analysis included gross and histological examination and PCR in the liver, spleen, brain, lymph nodes, and lungs. PCR and Giemsa staining were used for parasite identification. A second cow belonging to the same farm was positive for Trypanosoma theileri by PCR performed on blood sample. In this case, the postmortem analysis included also testis. Clinical examination showed only a reduction in body weight in both cases. The CBC revealed an increase of lymphocytes and neutrophils while red blood cells were within the normal range. Spleen was slightly increased in volume and the histology revealed a proliferative activity of the white and red pulp. The biomolecular analysis identified the parasite as Trypanosoma theileri and its DNA was detected in the bone marrow, testis, and brain. The unusual finding of parasite in the brain, testis, and bone marrow raises new clinical implication on disease course and also possible sexual transmission.

Circulation of a novel strain of dolphin morbillivirus (DMV) in stranded cetaceans in the Mediterranean Sea

Dolphin morbillivirus (DMV) has been responsible for several outbreaks of systemic infection and has resulted in cetacean strandings in the Mediterranean. In August-October 2016, seven striped dolphins (Stenella coeruleoalba) stranded on the Sicilian coastline (Italy) tested positive for DMV. Tissue samples from brain, lung, pulmonary lymph nodes, heart, spleen, liver, stomach, intestine, kidneys and urinary bladder, as well as blowhole swabs, were collected during necropsy for molecular diagnostics and pathology studies. Extracted tissue RNA was screened for DMV by real-time reverse transcription polymerase chain reaction (PCR). Some tissues exhibited microscopic lesions that were consistent with DMV infection on histopathological and immunohistochemical grounds. Conventional reverse transcription PCR to target partial nucleoprotein and phosphoprotein genes yielded sequences used to genetically characterize the associated DMV strain. DMV RNA was detected by both PCR assays in all tested tissues of the seven dolphins, which suggests systemic infections, but was absent from another dolphin stranded on the Sicilian coastline during the same period. The partial phosphoprotein and nucleoprotein gene sequences from the positive dolphins were 99.7% and 99.5% identical, respectively, to the DMV sequences recently observed in cetaceans stranded on the Spanish Mediterranean. Our study suggests that this DMV strain is circulating in the Mediterranean.

Immunological response in horses following West Nile virus vaccination with inactivated or recombinant vaccine

To evaluate the immunological response following vaccination, 40 WNV serologically negative horses were selected and divided in two groups of 20 animals. One group was vaccinated (booster after 28 days) with a whole inactivated viral strain and the second group with a live recombinant canarypox virus expressing the genes coding for the WNV preM/E viral proteins. IgM, IgG and neutralizing antibodies were monitored by class specific ELISAs and serum neutralization assay for 360 days. In both groups, IgM antibodies were first detected 7 days post vaccination (dpv). However, in the group vaccinated with inactivated vaccine, IgM antibodies were detected until day 42 pv, whereas in the group vaccinated with the recombinant vaccine, they were detected up to day 52 pv. A similar (P > 0.05) proportion of horses showed IgM antibodies after vaccination with either recombinant [30%; 95% confidence interval (CI): 14.59%-52.18%] or inactivated (32%; 95% CI: 15.39-54.28%) vaccine. Both vaccines induced in vaccinated horses a detectable IgG antibody response starting from day 7 pv and lasting till the end of the trial. Analogously, both products elicited WNV specific neutralizing antibodies. The response induced by the live canarypox virus-vectored vaccine was higher (mean titres 1:298 vs 1:18.9) and lasted longer than did that induced by the killed-virus vaccines. In fact, one year after the vaccination, neutralizing antibodies were still detectable in the horses which received the canarypox virus-based vaccine but not in the group vaccinated with the killed product. The use of vaccines is a valuable tool to prevent WNV disease in horses and the availability of different products facilitates the control of the disease in endemic areas.

Update on canine distemper virus (CDV) strains of Arctic-like lineage detected in dogs in Italy

Canine distemper virus (CDV) is the etiologic agent of distemper in dogs. It exhibits an elevated potential of crossing species barriers, infecting a wide range of wild and domestic carnivores. Of its encoding genes, hemagglutinin (H) shows high heterogeneity, and it was used to determine the relationship between CDV strains due to its variability and key role in determining cell tropism, host shift, and in eliciting a protective immune response. This study analysed the full-length H gene sequence of Arctic-like CDV strains collected from dogs in Italy during a period in which an increased activity of CDV diffusion was observed. The common amino acid changes and features of Arctic-like CDV strains collected from 2011 to 2016 in Europe were described, providing an updated analysis of the genomic features. A comparison with CDV vaccine strains was carried out to evaluate the increased genomic difference with CDV Arctic-like field strains. This study provides a complete and updated analysis of the current spreading strains of Arctic-like lineage and the main amino acid variations in the hemagglutinin gene sequence circulating in Italy. Moreover, it provides novel information regarding the evolution of the most recent CDV Arctic-like lineage strains collected in Europe.

Bluetongue virus serotype 3 in Western Sicily, November 2017

Bluetongue virus serotype 3 has been detected in a sheep in the Western part of the island of Sicily (Italy). This area is 150 km away from the peninsula of Cap Bon (Tunisia), where recent activities included in the Bluetongue National Surveillance plan demonstrated the widespread circulation of the same BTV strain.

Detection and molecular characterization of betanodaviruses retrieved from bivalve molluscs

Betanodaviruses are small ssRNA viruses responsible for viral encephalopathy and retinopathy, otherwise known as viral nervous necrosis, in marine fish worldwide. These viruses can be either horizontally or vertically transmitted and have been sporadically detected in invertebrates, which seem to be one of the possible viral sources. Twenty-eight new betanodavirus strains were retrieved in three molluscs species collected from different European countries between 2008 and 2015. The phylogenetic analyses revealed that strains retrieved from bivalve molluscs are closely related to viruses detected in finfish in Southern Europe in the period 2000-2009. Nevertheless, a new betanodavirus strain, markedly different from the other members of the RGNNV genotype, was detected. Such a massive and varied presence of betanodaviruses in bivalve molluscs greatly stresses the risks of transmission previously feared for other invertebrates. Bivalve molluscs reared in the same area as farmed and wild finfish could act as a reservoir of the virus. Furthermore, current European regulations allow relaying activities and the sale of live bivalve molluscs, which could pose a real risk of spreading betanodaviruses across different geographic regions. To our knowledge, this is the first study, which focuses on the detection and genetic characterization of betanodaviruses in bivalve molluscs.

Molecular typing of a novel canine parvovirus type 2a mutant circulating in Italy

Canine parvovirus (CPV) is the etiological agent of a severe viral disease of dogs. After its emergence in late 1970s, the CPV original type (CPV-2) was rapidly and totally replaced by three antigenic variants named CPV-2a, CPV-2b and CPV-2c. CPV has an evolutionary rate nearest to those of RNA viruses, with consequences on disease diagnosis and epidemiology. This paper reports the molecular characterization of eight CPV-2a strains collected from dogs in Italy in 2016–2017. Genetic analysis was conducted on a CPV genomic region encompassing both open reading frames (ORFs) encoding for nonstructural (NS1-NS2) and structural proteins (VP1-VP2). Sequence analysis indicates new and unreported sequence changes, mainly affecting the VP2 gene, which included the mutation Tyr324Leu. This study represents the first evidence of a new CPV-2a mutant (VP2 324Leu) and illustrates the importance of a continuous molecular survey in order to obtain more information on effective spread of new CPV mutants.

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Canine parvovirus strains collected from dogs in southern Italy were analyzed.

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Nearly complete genome sequences of the CPV strains were obtained and comparatively analyzed.

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A novel CPV-2a mutant with unreported sequence changes has been characterized.

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This study reports a novel CPV-2a mutant in genus Protoparvovirus.

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Our data confirmed the importance of the continuous epidemiological survey.

Introduction of Asian canine parvovirus in Europe through dog importation

Canine parvovirus (CPV) is an important infectious agent of domestic and wild carnivores, responsible for severe and often fatal haemorrhagic gastroenteritis and leukopenia. This paper reports the genomic characterization of a CPV strain collected from a dog recently imported to Italy from Thailand. The virus was detected in all tissue samples collected. The whole genome encompassing the two open reading frames encoding for non‐structural (NS1/NS2) and structural (VP1/VP2) proteins was amplified and sequenced. On the basis of genetic analysis of the VP2 gene, the isolate was characterized as CPV‐2c, but it presented genetic signatures typical of Asian strains. Sequence analysis revealed the presence of amino acid changes never observed in European CPV‐2c strains (NS1: Ile60Val, Tyr544Phe, Glu545Val, Leu630Pro; VP2: Ala5Gly, Phe267Tyr, Tyr324Ile, Gln370Arg). By phylogenetic analysis of full‐length VP2 gene, the analysed strain clustered together with Asian viruses. Therefore, a possible introduction of the virus from Asia through the imported dog was suggested, thus confirming the important role of movement of dogs in the global spread of viruses. In addition, full‐length genome analysis could help better trace the spread of canine viruses through different continents.