Virological Investigation in Synanthropic Rodents in North Italy

Intro: Several rodents, including mice and the brown rat, are synanthropic animals usually found in rural and urban environments in contact with other animals and humans. Rodents are natural reservoirs of infectious agents and could harbour a plethora of zoonotic pathogens of public health importance. Taking advantage of a parallel study on presence and distribution of Hantaviruses, we aimed to investigate the occurrence in mice of other viruses with zoonotic or economic impact. Method(s): From May to July 2022, 41 mice (Mus domesticus) were captured and killed by using baited snap traps in 13 selected cattle, goat and poultry farms located in the Piedmont region. Gut and lung samples were homogenised and tested by PCR methods for pan-Coronavirus (CoV) and SARS-CoV-2, pan-Pestivirus, Mammalian orthoreoviruses, Canine Distemper virus (CDV), Flaviviruses, Influenza A (IAV) and D (IDV) viruses. Finding(s): All captured animals did not present at necropsy lesions related to infectious diseases. Virological investigations detected the presence of CoV in six mice. By sequencing Rodent CoVs was identified in two samples (four more pending). Mammalian orthoreovirus was detected in nine animals and typing and characterization are in progress. One mouse, captured in a bovine farm, tested slightly positive for IDV and confirmation of positivity is in progress by complete sequencing with NGS approach. All samples were negative for Flaviviruses, IAV, CDV, pan-Pestivirus and SARS-CoV-2. Conclusion(s): Rodents are well adapted to a wide range of habitats, including peri-urban and rural environments, where they benefit from human activities. These results, although preliminary, underline the importance of enhancing surveillance in rodents in anthropized areas to better assess the presence of zoonotic agents and the potential risk of transmission.Copyright © 2023

Disease threats to tigers and their prey

The contraction of the global tiger population over the last 100 years into small, often isolated subpopulations has made them increasingly vulnerable to the impact of disease. Despite this, the health of wild tigers continues to be insufficiently funded and explored. For example, canine distemper virus (CDV), has been associated with localized declines and increased risk of extinction, and yet has received little research attention in most tiger range countries. The emergence of new pathogenic threats has posed fresh challenges, including African swine fever virus (ASFV), which has the potential to devastate wild boar populations, and severe acute respiratory syndrome coronavirus (SARS-CoV2) with implications for tiger conservation that remain unknown. The objective of this review is to synthesize current research on the health of tigers and their prey that impacts the conservation of tigers in the wild. Published sources are interpreted based on three mechanisms through which disease can affect the viability of tiger populations: (1) by reducing the survival of adult tigers, (2) by reducing breeding productivity, and (3) by reducing the carrying capacity of tiger habitat through decreased prey abundance. Examples of CDV, SARS-CoV2, carnivore protoparvovirus 1 and ASFV are used to illustrate these processes and inform discussion of research and mitigation priorities. Copyright © 2023 Gilbert, Dvornicky-Raymond and Bodgener.

Surveillance and Analysis of Canine Respiratory Coronavirus Infection in Beijing

This study aimed to analyse the pathogenic characteristics and the epidemiological situation of canine respiratory coronavirus (CRCoV) in Beijing. From December 2015 to March 2017, Pharynx nasal swabs from 487 dogs were collected and reverse transcriptional polymerase chain reactions was used to detect CRCoV. Meanwhile, some of the samples were also used to detected canine parainfluenza virus (CPIV), canine adenovirus type 2 (CAV-2) and canine distemper virus (CDV) for exploring the situation of mixed infection. The results showed that: 1) The positive rates of CRCoV was 21.36% (104/487). The mixed infection rates of CRCoV and CPIV, CAV-2, CDV were 3.43% (11/321), 0% (0/156) and 3.85% (6/156) respectively. 2) Among all 455 cases which had respiratory symptom records, dogs which had non-respiratory symptom accounting for 27.19% of all dogs without respiratory symptoms, dogs which had mild respiratory symptoms (coughing and nasal discharging) accounting for 19.73% of all dogs with mild respiratory symptoms, dogs which had moderate to severe respiratory symptoms (pneumonia) accounting for 14.28% of all dogs with moderate to severe respiratory symptoms. 3) From November 2016 to March 2017, the mixed infection between CRCoV and CPIV, CAV-2, CDV in 146 cases was explored. The mixed infection rates of the dogs which were tested CRCoV positive and had non-respiratory symptom was 12.50%. The mixed infection rates of the dogs which were tested CRCoV positive and had mild respiratory symptoms was 41.18%. The mixed infection rates of the dogs which were tested CRCoV positive and had moderate to severe respiratory symptoms was 100.00%. 4) The infection rates of CRCoV varied from 15.56% to 22.97% in different age groups among 454 samples. Except for the high positive rates in July, the positive rates in cold season is higher than warm season. These results indicated that the pathogenicity of CRCoV is rather weak. Dogs suffer pure infection of this virus often show non-respiratory symptom or mild respiratory symptoms. Dogs which are CRCoV positive suffer mixed infection often show mild respiratory symptoms or moderate to severe respiratory symptoms. This virus is more likely to be prevalent in winter and spring. The infection rates has no significant relationship with age. Copyright © 2022 Editorial Board, Institute of Animal Science of the Chinese Academy of Agricultural Sciences. All rights reserved.

Antiviral activity of canine interferon lambda 3 expressed using a recombinant adenovirus against canine coronavirus, canine parvovirus, and canine distemper virus.

Canine coronavirus (CCoV), canine parvovirus (CPV), and canine distemper virus (CDV) are highly contagious canine pathogens; dogs with these diseases are difficult to treat. In a previous study, we developed a recombinant adenovirus expressing canine interferon lambda 3 (Ad-caIFNλ3) in canine epithelial cells. In this study, we aimed to investigate the antiviral activity of Ad-caIFNλ3 against CCoV, CPV, and CDV in two canine cell lines, A72 and MDCK. Ad-caIFNλ3 transduction suppressed replication of these viruses without cytotoxicity. Our results suggest that Ad-caIFNλ3 may be a therapeutic candidate for canine viral diseases.

Serum Calprotectin Levels in Dogs with Diarrhea

Background: Diarrhea induced by infectious factors may lead to significant health problems in dogs. Canine parvovirus (CPV), canine coronavirus (CCV), canine distemper virus (CDV), Giardia spp., Escherichia coli (E. coli), and Salmonella spp. are the important infectious agents that may induce diarrhea in dogs. The present study aimed to investigate the effect of CPV, CCV, CDV, Giardia spp., E. coli, and Salmonella spp. infections on the change in serum calprotectin (Calp) concentration. Materials, Methods & Results: A total of 30 dogs were enrolled in the study. The study dogs were divided into 3 groups. Healthy animals as confirmed by clinical examination and animals negative for the specified pathogens were placed in Group 1. Animals infected by one or more agents, including CPV, CCV, CDV, and Giardia spp., but negative for E. coli or Salmonella spp. were placed in Group 2. Finally, animals positive for E. coli or Salmonella spp. and infected or not infected by one or more agents, including CPV, CCV, CDV, and Giardia spp., were placed in Group 3. Stool samples and rectal and conjunctival swab samples were collected to investigate the etiologic agents that induced diarrhea. Blood samples were collected through vena cephalica antebrachii for hematological and biochemical examinations. The samples were obtained via routine clinical examinations at the Prof. Dr. Servet Sekin outpatient clinic at Dicle University Veterinary Faculty. CPV, CCV, CDV, and Giardia spp. diagnoses were made based on immunochromatographic test kits. The bacteriological analysis of stool samples was used to diagnose E. coli and Salmonella spp. infection. Serum Calp concentrations were measured by Enzyme-Linked Immunosorbent Assay (ELISA). The analysis of swab and stool samples by immunochromatographic rapid diagnosis kits and microbiological methods showed that 5 animals were infected with CPV, 10 with CCV, 6 with CDV, 3 with Giardia spp., 12 with E. coli, and 2 with none of the specified agents. Total leukocyte count (WBC), lymphocyte (Lym - %), and granulocyte (Gra - %) values were higher in the diarrheal dogs when compared with the control group. In the biochemical examination of serum samples, total bilirubin (TBIL) and phosphorus (P) levels were higher and sodium (Na) levels were lower in Group 3 when compared to the control group (P = 0.025, 0.024, and 0.018, respectively). Total protein (TP) and albumin (Alb) values were lower in Group 2 compared to Groups 1 and 3 [P = 0.001 and 0.019 for TP, P = 0.000 and 0.01 for Alb, respectively]. There was a statistically significant difference in creatine kinase (CK) levels between Group 1 and Group 2 (P = 0.013). Serum Calp level was higher in the E. coli infected group (Group 3) compared to the other groups, no significant differences were noted between the groups (P > 0.05). Discussion: In conclusion, to the best of authors knowledge, this study is the first to evaluate serum Calp levels in dogs with diarrhea induced by viral, bacterial, and protozoan infections. The Calp level was higher in the sick dogs that were infected by at least one agent, including CPV, CCV, CDV, and Giardia spp., and were at the same time E. coli positive when compared with the control group and the group without E. coli infections. It was concluded that new studies could be useful to reveal the diagnostic importance of serum Calp concentration in dogs with diarrhea and that these results may contribute to future studies in this area.

Fabrication of an Oscillating Thermocycler to Analyze the Canine Distemper Virus by Utilizing Reverse Transcription Polymerase Chain Reaction.

The reverse transcription-polymerase chain reaction (RT-PCR) has been utilized as an effective tool to diagnose the infectious diseases of viruses. In the present work, the oscillating thermocycler is fabricated and performed to carry out the one-step RT-PCR process successfully. The ribonucleic acid (RNA) mixture is pipetted into the fixed sample volume inside an aluminum reaction block. The sample oscillates the pathway onto the linear motion control system and through the specific RT-PCR heating zones with individual homemade thermal control modules. The present oscillating thermocycler combines the merits of the chamber type and the CF type systems. Before PCR, the reaction chamber moves to the low-temperature zone to complete the RT stage and synthesize the complementary deoxyribonucleic acid (DNA). Next, the low-temperature zone is regulated to the annealing zone. Furthermore, the reactive sample is moved back and forth among three isothermal zones to complete PCR. No extra heating zone is required for the RT stage. The total length of the moving displacement of the chamber is within 100 mm. The miniaturization of the oscillating thermocycler can be expected. In our oscillatory device, the denaturation zone located between the annealing and extension zones is suggested as the appropriate arrangement of the heating blocks. Heat management without thermal cross-talk is easy. Finally, an improved oscillating device is demonstrated to execute the RT-PCR process directly, utilized to amplify the canine distemper virus templates successfully, which could be well applied to a low-cost DNA analysis system in the future.

Compatibility between a rabies vaccine and two canine combined vaccines against canine distemper, adenovirosis, parvovirosis, parainfluenza virus disease and leptospirosis, with or without canine coronavirus.

In many countries, vaccination programs still require dogs to be vaccinated against rabies in addition to Canine distemper virus (CDV), adenovirus (CAV), parvovirus (CPV), parainfluenza virus (CPiV), Leptospira (L) or Canine coronavirus (CCV= Cv). Few vaccines containing all these antigens are commercially available and, unless compatibility between the vaccines was demonstrated, concurrent administration of a DAPPi-L(Cv) vaccine and a vaccine against rabies should not be recommended. This may be of concern for practitioners who wish to vaccinate dogs with all components on the same day. This study aimed at evaluating immunological compatibility between a monovalent rabies vaccine (Rabisin™) and two large combination vaccines against CDV, CAV, CPV, CPiV with 2 leptospira components +Cv (Recombitek® C6/Cv) or with 4 Leptospira components (Recombitek® C8), when injected concomitantly at two separate injection sites. Fourteen days after administration of the rabies vaccine, with or without concomitant administration of combo vaccines, all dogs had seroconverted against rabies and maintained protective titers over the duration of the study. In addition, 100% of the puppies vaccinated with one or the other combo vaccines seroconverted against CDV, CAV, CPV, CPiV (CCV) and Leptospira, whatever the vaccination group. Lack of immunological interference between Rabisin™ and all components of the Recombitek® C6/Cv or Recombitek® C8 Combo vaccines was demonstrated by non-inferiority analysis, except for CDV in the Recombitek®C8+ Rabisin™ group. Based on these results, a concomitant administration of Rabisin™ with Recombitek® C6/Cv or Recombitek® C8 can be recommended in daily practice, which can be essential for facilitating vaccination compliance.

Rescue of recombinant canine distemper virus that expresses S1 subunit of SARS-CoV-2 spike protein in vitro.

The coronavirus disease 2019 (COVID-19), as an unprecedented pandemic, has rapidly spread around the globe. Its etiological agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), belongs to the genus Betacoronavirus in the family Coronaviridae. The viral S1 subunit has been demonstrated to have a powerful potential in inducing protective immune responses in vivo. Since April 2020, farmed minks were frequently reported to be infected with the SARS-CoV-2 in different countries. Unfortunately, there has been no available veterinary vaccine as yet. In this study, we used reverse genetics to rescue a recombinant canine distemper virus (CDV) that could express the SARS-CoV-2 S1 subunit in vitro. The S1 subunit sequence was demonstrated to be relatively stable in the genome of recombinant CDV during twenty serial viral passages in cells. However, due to introduction of the S1 subunit sequence into CDV genome, this recombinant CDV grew more slowly than the wild-type strain did. The genomic backbone of recombinant CDV was derived from a virulence-attenuating strain (QN strain). Therefore, if able to induce immune protections in minks from canine distemper and COVID-19 infections, this recombinant would be a potential vaccine candidate for veterinary use.