The ovine respiratory syncytial virus F gene sequence and its diagnostic application

The role of Mycoplasma ovipneumoniae and Mycoplasma arginini in the respiratory mycoplasmosis of sheep and goats in Italy: Correlation of molecular data with histopathological features

Mycoplasma infections are commonly found in the respiratory system of small ruminants; the species most commonly detected are Mycoplasma ovipneumoniae and Mycoplasma arginini, associated with the so-called "atypical non-progressive pneumonia". The pathogenic role of M. ovipneumoniae in pneumonia has been demonstrated in sheep but still needs to be verified in goats; on the other hand, the role of M. arginini in sheep is not well understood, while in goats seems to be of low pathogenic value. The present study aims to investigate the aetiology of pneumonia in sheep and goats that died from respiratory disease using anatomopathological, histopathological, and molecular investigations and to clarify the role of respiratory mycoplasmas by the association of molecular data with histopathological features. First, to better understand which histological changes are actually suggestive of atypical pneumonia in sheep and goats, the study identified the histological lesions significantly associated with Mycoplasma spp. infection. Then, the histological score of lesions considered suggestive of atypical pneumonia was used to estimate the pathogenicity of each mycoplasma detected. The results showed that M. ovipneumoniae and M. arginini (alone or in mixed infections) are pathogenic both in sheep, as well as in goats with similar histology and severity of lesions. Moreover, young animals were statistically more susceptible to M.ovipneumoniae and M. arginini infection than adults. Animals appeared more at risk to the development of M. ovipneumoniae and M. arginini infection in summer.

African Swine Fever: The State of the Art in Italy

African swine fever (ASF) is a severe viral disease of domestic pigs and Eurasian wild boars (Sus scrofa) caused by the African swine fever virus (ASFV). ASF is endemic in sub-Saharan Africa, where 24 genotypes of the virus have been reported. Between the late 1950s and the early 1980s, genotype I ASFV emerged in Europe, including Italy. In June 2007, a second ASF epidemic wave caused by genotype II was registered, involving several European and extra-European countries, including Italy in 2022. The present paper aims to provide the state of the art of ASF in Italy, describing the course of ASF in wild boars and domestic pigs as an example of multiple concurring different scenarios. Sardinia is coping with the last phase of the eradication of the disease by applying the exit strategy. Conversely, four clusters of infection located in North, Central, and South Italy are still ongoing. The unique and complex Italian experience in ASF-controlling may be useful to increase know-how on the efficacy of strategies and measures, as well as issues that could be further improved.

Isolation and Identification of Aeromonas veronii in Sheep with Fatal Infection in China: A Case Report

According to the findings of a sheep breeding farm in Shaanxi, China, 2.53% (15/594) of sheep exhibited respiratory (clinical) symptoms such as dyspnoea, nasal discharge, wet cough, fever, and progressive emaciation. Although multi-drug treatment strategies (including ampicillin, tylosin, florfenicol, and ceftiofur) have been attempted to improve clinical outcomes, they have only been met with limited success, with a mortality rate of 40%. Ultimately, Aeromonas veronii (A. veronii) was identified as the causative pathogen for respiratory disease. The rates of symptomatic and asymptomatic sheep positive to A. veronii were 64.28% (95% CI 52.25-76.31%) and 8.02% (95% CI 6.96-9.08%), respectively. Pathogenicity tests demonstrated that the A. veronii is pathogenic to sheep and mice. The results of the antibiotic susceptibility tests revealed that the strain was sensitive to cefotaxime, gentamicin, and enrofloxacin and resistant to ampicillin, ceftiofur, amoxicillin, kanamycin, neomycin, streptomycin, tetracycline, florfenicol, and tylosin. We suggest that the combination of cefotaxime and gentamicin is an effective treatment based on the results of an antimicrobial susceptibility test, which exhibited good therapeutic efficacy. To the best of our knowledge, this is the first report in which pathogenic A. veronii has been documented as the cause of death in sheep in China. We concluded that pathogenic A. veronii poses a potential risk to the industry of sheep husbandry. This study's findings can help guide prevention and treatment plans for A. veronii infection in sheep.

Respiratory Syncytial Virus Infection Induces Expression of Inducible Nitric Oxide Synthase, CD3, and CD8 in Naturally Occurring Pneumonia in Lambs

Respiratory syncytial virus (RSV) is an RNA virus that belongs to the Pneumovirus genus of the Paramyxoviridae family. The aim of this study was to evaluate the expressions of inducible nitric oxide synthetase (iNOS), CD3 (pan T cells), and CD8 (cytotoxic T cells) in lamb lungs naturally infected with RSV using immunohistochemistry (IHC). For this purpose, 100 pneumonic and 10 control lung tissue samples were taken from lambs slaughtered in the slaughterhouse after macroscopic examination. The streptavidin– peroxidase method (ABC) was used for IHC staining, and it revealed RSV positivity in 18 of 100 examined lungs with pneumonia (18%). These positive cases were then immunostained for iNOS, CD3, and CD8, and compared to controls. In all these cases, an increase in iNOS expression (100%) was detected, the higher number of CD3+ T lymphocytes was detected in 14 (78%) cases while CD8+ T lymphocytes were detected in five (28%) cases, only. Given the increase of iNOS immunoexpression in all RSV-positive cases and increase in the number of CD3+ T lymphocytes in most cases, it was concluded that iNOS and CD3+ T lymphocytes play an important role in the immune response in lamb pneumonia with naturally occurring RSV infection. With this study, the role of the mentioned markers was evaluated for the first time in lambs naturally infected with RSV.

First report of immunohistochemical detection of Peste des petit ruminants, parainfluenza 3 and respiratory syncytial viral antigens in lungs of Nigerian goats

This study determined the of involvement of PPR, PI3, and RS viruses in the pathology of caprine pneumonia across Nigeria. 150 goats were selected randomly. PI3 and RSV monoclonal antibodies and PPR polyclonal antibody were used for the immunolocalization of the antigens. Histologically, 61 of the goats had broncho-interstitial pneumonia, 25 had interstitial pneumonia, 42 had bronchopneumonia, 12 had bronchiolitis, and 10 were normal. PPR, PI3, and RS viral antigens were demonstrated in: intact and desquamated bronchial, bronchiolar epithelial cells, macrophages, leukocytes, pneumocytes, and giant cells. 23% of the caprine lungs had positive immuno-staining to PI3 viral antigen, 10% were positive for RSV antigen while 34% were positive for PPR viral antigen. 8% showed immunostaining for the two and or three respiratory viral antigens in the goats. PI3 and RSV antigens were more in the young goats, red sokoto breed and during the dry season. This is the first report of immunohistochemical detection of PPR, PI3 and RS viral antigens in caprine lungs in Nigeria. These findings underscore the importance of PI3 and RSV viruses in the control of caprine pneumonia in Nigeria.

A novel parainfluenza virus type 3 (PIV3) identified from goat herds with respiratory diseases in eastern China

Parainfluenza virus type 3 (PIV3) is one of the most important viral respiratory pathogens for humans and for many animals, but goat infection has been rarely reported. Starting in Aug 2013, goats in the Jiangsu and Anhui provinces of eastern China suffered severe respiratory diseases. In order to identify the causative agent, numerous related pathogens were tested with RT-PCR or PCR. A unique PIV3 strain was detected in most of the clinical nasal swabs or serum samples. The virus was isolated on MDBK cells and characterized by RT-PCR, nucleotide sequence analysis and hemagglutination test. The entire M and F gene coding regions, HN, 5'-UTR-N and L gene fragments were amplified using pairs of degenerate primers. Nucleotide, amino acid sequence alignments and phylogenetic analyses based on these genes indicated that the goat-derived PIV3 strain was distinct from previously reported BPIV3 genotypes and HPIV3 strains. The novel isolate, named JS2013, might be a potentially new member of the respirovirus genus. Goats were experimentally infected with JS2013 culture. The virus-inoculated goats displayed coughing and nasal discharges that were related to respiratory diseases. Viremia and virus shedding were detected during 4-10 days post-inoculation (dpi). Virus-specific HI antibodies became positive from 14 dpi. This is the first report of the detection of PIV3 from Chinese goat herds and genetic and pathogenetic characterization of the novel goat-derived PIV3.

Serological study of a population of alpine chamois (Rupicapra r rupicapra) affected by an outbreak of respiratory disease

A serological survey of respiratory virus infections was carried out from 1998 to 2001 in Lecco province, Italy, as part of a health monitoring programme in a population of alpine chamois, many of which died of pneumonia in autumn and winter 2000 to 2001; 194 carcases of all age classes were found over a short period and in a small area. Eighteen of them, which were examined postmortem, consistently showed signs of severe fibrinous lobar pneumonia or catarrhal bronchopneumonia. Samples of serum from 145 chamois collected from hunted animals and carcases were tested by a virus neutralisation test against bovine respiratory syncytial virus (BRSV), bovine viral diarrhoea virus, bovine herpesvirus type 1 and parainfluenzavirus type 3. Positive results were detected only for BRSV. The area was divided into two subunits on the basis of the distribution of deaths; in the areas where fatalities were observed there was a significant increase of BRSV titres at the beginning of the outbreak. Furthermore, during the 2000 and 2001 hunting seasons antibody titres to BRSV were significantly higher in the areas where mortality occurred. The roe deer living in the same area were not affected by pneumonia and had a low prevalence of titres to BRSV which did not vary during the period of the study.

Comparison of targeting F and G protein genes to detect bovine and ovine respiratory syncytial viruses

In this study, 2 reverse transcriptase-polymerase chain reaction (RT-PCR) assays were developed and compared for simultaneous detection of bovine and ovine respiratory syncytial viruses (RSVs). One assay was based on a set of primers, which amplified a 426-bp fragment of either bovine or ovine RSV F gene (RT-PCR F). The F products could be distinguished by EcoRI or BstYI restriction endonuclease cleavage. In the other assay, a set of primers amplified a 542-bp fragment of either ovine or bovine RSV G gene (RT-PCR G). EcoO1091 and RsaI restriction enzymes were used to differentiate between the ovine and bovine PCR-G products. Sequencing of the PCR products confirmed the fidelity of both assays. The 2 assays were evaluated using 18 bovine RSV isolates, 1 ovine RSV, 1 bighorn sheep RSV isolate, 1 caprine RSV isolate, 2 human RSV isolates, and several other viruses associated with bovine respiratory tract disease. RT-PCR G may be more sensitive in detecting viral RNA. Because the target sequence of the F gene is more conserved than that of the G gene, RT-PCR F followed by the appropriate restriction enzyme cleavage may be superior to RT-PCR G to discriminate between the 2 ruminant RSV subgroups. This assay should prove useful for determining the relative contribution of ovine and bovine RSV to the pathogenesis of bovine respiratory tract disease.