Mycobacterium bovis is the main causative agent of bovine tuberculosis (BTB) in cattle and it is also responsible for a proportion of human TB cases. The annual cost of BTB worldwide is estimated at US$3 billion. Zebu cattle are considered to be more resistant to some infectious diseases than Holstein-Friesian (HF) cattle, including BTB. However, epidemiological studies do not necessarily take into account usage differences of the two types of cattle. It could be argued that HF cattle suffer greater metabolic stress due to their mainly dairy use, whereas Zebu cattle are mainly used for beef production. However, in experiments comparing Zebu and European cattle, the number of animals has been too small to draw statistically robust conclusions on the differences in the level of resistance between these breeds of cattle. Here, we used a recently developed vaccination-and-BCG challenge model to compare the ability of naïve and vaccinated Zebu and HF cattle to control/kill mycobacteria. Young male cattle of both breeds with similar ages were housed in the same accommodation for the duration of the experiment; after correcting for multiple comparison, we found that there was a trend for vaccinated HF cattle to have lower cfu numbers than non-vaccinated HF cattle (ρ = 0.057). No such trend was observed between vaccinated and non-vaccinated Zebu cattle (ρ = 0.560); similarly, no difference was observed between naïve HF and Zebu (ρ = 0.862) cattle. In contrast, evaluation of antigen-specific IFNγ secretion indicated that Zebu and HF cattle differed in their response to mycobacteria. Thus, under the conditions used in this work, the data indicate that there are no differences between Zebu and HF cattle. Further experiments, using larger numbers of animals may be required to determine whether Zebu and HF cattle differ in their susceptibility to infection with M. bovis.
Bovine tuberculosis (bTB) prevalence substantially increased over the past two decades with relatively high impact on large dairy herds, raising the concern of regulatory authorities and industry stakeholders, and threatening animal and public health. Lack of resources, together with the economic and social consequences of whole-herd stamping-out, makes depopulation an impractical disease control alternative in these herds. The increase in bTB-prevalence was associated with demographic and management changes in the dairy industry in Uruguay, reducing the efficacy of the current control program (i.e. status quo) based on intradermal serial testing with caudal fold- and comparative cervical- tuberculin test-and slaughter of reactors (CFT-CCT). Here, we aimed to assess the epidemiological effectiveness of six alternative control scenarios based on test-and-slaughter of positive animals, using mathematical modeling to infer bTB-within-herd dynamics. We simulated six alternative control strategies consisting of testing adult cattle (>1 year) in the herd every three months using one test (in-vivo or in-vitro) or a combination in parallel of two tests (CFT, interferon-gamma release assay –IGRA- or Enzyme-linked immunosorbent assay). Results showed no significant differences overall in the time needed to reach bTB-eradication (median ranging between 61 to 82 months) or official bovine tuberculosis-free status (two consecutive negative herd-tests) between any of the alternative strategies and the status quo (median ranging between 50 and 59 months). However, we demonstrate how alternative strategies can significantly reduce bTB-prevalence when applied for restricted periods (6, 12, or 24 months), and in the case of IGRAc (IGRA using peptide-cocktail antigens), without incurring on higher unnecessary slaughter of animals (false-positives) than the status quo in the first 6 months of the program (P-value <0.05). Enhanced understanding bTB-within-herd dynamics with the application of different control strategies help to identify optimal strategies to ultimately improve bTB-control and -eradication from dairies in Uruguay and similar endemic settings.
Carnivore protoparvovirus 1 is one of the most important pathogens affecting both wild and domestic carnivores. Here, we reported the genetic characterization of canine parvovirus strains from a rescued guiña (Leopardus guigna) and domestic dogs from Chile. Guiña sequence was classified as CPV-2c and phylogenetic analysis of the complete coding genome showed that the guiña CPV-2c strain share a recent common ancestor with Chilean domestic dogs strains. These viruses presented >99% identity and showed three changes in the NS1 protein, CHL-17 V596A, CHL-71 E661K and CHL-guigna L582F. This is the first detection and genetic characterization of CPV-2c infection in guiña worldwide and one of the few comparative studies that undoubtedly determine that the source of infection were domestic dogs. The current findings highlight that guiña is a susceptible species to protoparvovirus infection and that domestic dogs represent an important thread to its conservation. The CPV cross-species transmission between domestic dogs and guiña should be taken into account for protection programs of this endangerous species.
The outbreak of COVID-19 as a pandemic has shaken the global health system and economy by their roots. This epidemic is still spreading and showing no signs of decreasing trend. Vaccination is the only effective and economical means to control this pandemic. A number of research institutions and pharmaceutical companies have plunged into the race of vaccine development against COVID-19 which are in various stages of development. An intriguing fact of coronavirus infections is that in every decade of 21st century there is a new major coronavirus epidemic viz. SARS in 2002, MERS in 2012, and now COVID-19; and such epidemics are expected in future too. Since, maximum biological characteristics of SARS-CoV-2 are still obscure the scientists are relying on the information available on SARS-CoV and to some extent on MERS-CoV for designing and development of COVID-19 vaccines. But there is a need of vigorous testing for immunogenicity, safety, efficacy, and level of protection conferred in the hosts. This review focuses on the challenges and prospects of vaccine development against COVID-19. It highlights seriousness, bottlenecks in vaccine development, possible vaccine candidates, different vaccine strategies, safety evaluation issues, and vaccine production process pertaining to COVID-19 based on the knowledge acquired on SARS and MERS vaccine development in the past.
After its first description in Wuhan (China), SARS-CoV-2 the agent of coronavirus disease 2019 (COVID-19) rapidly spread worldwide. Previous studies suggested that pets could be susceptible to SARS-CoV-2. Here, we investigated the putative infection of SARS-CoV-2 in 22 cats and 11 dogs from owners previously infected or suspected of being infected by SARS-CoV-2. For each animal, rectal, nasopharyngeal swabs and serum were taken. Swabs were submitted to RT-qPCR assays targeting 2 genes of SARS-CoV-2. All dogs were tested SARS-CoV-2 negative. One cat was tested positive by RT-qPCR on rectal swab. Nasopharyngeal swabs from this animal were tested negative. This cat showed mild respiratory and digestive signs. Serological analysis confirm the presence of antibodies against the SARS-CoV-2 in the two serum samples taken 10 days apart. Genome sequence analysis revealed that the cat SARS-CoV-2 belongs to the phylogenetic clade A2a like most of the French human SARS-CoV-2. This study reports for the first time the natural infection of a cat in France (near Paris) probably through their owners. There is currently no evidence that cats can spread COVID-19 and owners should not abandon their pets or compromise their welfare.
In the present study one hundred and sixteen partial G gene sequences of Avian metapneumovirus (aMPV) subtype B, obtained during routine diagnostics in different European Countries in the last few years (2014-2019), were analysed by sequence and phylogenetic analyses in order to draw an updated picture of the molecular characteristics of circulating strains. Nucleotide sequences were compared with other sequences of European and extra-European aMPV-Bs collected prior to that period or retrieved from GenBank. Phylogenetic relationships among the aMPV-B strains, reconstructed using the Maximum Likelihood method implemented in MEGA X, demonstrated that aMPV-B has evolved in Europe from its first appearance, frequently displaying a clear relation with the geographic area of detection. The 40% of aMPV-B viruses analysed were classified as vaccine-derived strains, being phylogenetically related, and showing high nucleotide identity with live commercial vaccine strains licensed in Europe. The remaining 60% were classified as field strains since they clustered separately and showed a low nucleotide identity with vaccines and vaccine-derived strains. The phylogenetic tree showed that the virus has continued to evolve from its first appearance in the ’80s since more recently detected strains belonged to clades phylogenetically distant from the older strains. Unlike vaccine-derived strains, field strains tended to cluster according to their geographic origin and irrespective of the host species where the viruses had been detected. In conclusion, the molecular characterization of aMPV-B and the differentiation between vaccines and field strains through G gene sequence analysis can be a useful tool towards correct diagnosis and should be routinely applied in order to better address the control strategies.
Even though antimicrobial-resistant bacteria have begun to be detected in wildlife, raising important issues related to their transmission and persistence of clinically important pathogens in the environment, little is known about the role of these bacteria on wildlife health, especially on endangered species. The Brazilian merganser (Mergus octosetaceus) is one of the most threatened waterfowl in the world, classified as Critically Endangered by the International Union for Conservation of Nature. In 2019, a fatal case of sepsis was diagnosed in an 8-day-old Brazilian merganser inhabiting a zoological park. At necropsy, major gross lesions were pulmonary and hepatic congestion. Using microbiologic and genomic methods, we identified a multidrug-resistant (MDR) extended-spectrum β-lactamase (ESBL) CTX-M-8-producing Escherichia coli (designed as PMPU strain) belonging to the international clone ST58, in celomic cavity, esophagus, lungs, small intestine and cloaca samples. PMPU strain harbored a broad resistome against antibiotics (cephalosporins, tetracyclines, aminoglycosides, sulfonamides, trimethoprim, and quinolones), domestic/hospital disinfectants, and heavy metals (arsenic, mercury, lead, copper, and silver). Additionally, the virulence of E. coli PMPU strain was confirmed using a wax moth (Galleria mellonella) infection model, and it was supported by the presence of virulence genes encoding toxins, adherence factors, invasins and iron acquisition systems. Broad resistome and virulome of PMPU contributed to therapeutic failure and death of the animal. In brief, we report for the first time a fatal colibacillosis by MDR-ESBL-producing E. coli in critically endangered Brazilian merganser, highlighting that besides colonization, critical priority pathogens are threatening wildlife. E. coli ST58 clone has been previously reported in humans, food-producing animals, wildlife, and environment, supporting broad adaptation and persistence at human-animal-environment interface.
The role of animal feed as a vehicle for the transport and transmission of viral diseases was first identified during the porcine epidemic diarrhea virus (PEDV) epidemic in North America. Since that time, various feed additives have been evaluated at the laboratory level to measure their effect on viral viability and infectivity in contaminated feed using bioassay piglet models. While a valid first step, the conditions of these studies were not representative of commercial swine production. Therefore, the purpose of this study was to evaluate the ability of feed additives to mitigate the risk of virus-contaminated feed using a model based on real-world conditions. This new model used an “ice-block” challenge, containing equal concentrations of porcine reproductive and respiratory syndrome virus (PRRSV), Seneca-virus A (SVA) and PEDV, larger populations of pigs, representative commercial facilities and environments, along with realistic volumes of complete feed supplemented with selected additives. Following supplementation, the ice block was manually dropped into designated feed bins and pigs consumed feed by natural feeding behavior. After challenge, samples were collected at the pen level (feed troughs, oral fluids) and at the animal level (clinical signs, viral infection, growth rate, and mortality) across five independent experiments involving 15 additives. In 14 of the additives tested, pigs on supplemented diets had significantly greater average daily gain (ADG), significantly lower clinical signs and infection levels, and numerically lower mortality rates compared to non-supplemented controls. In conclusion, the majority of the additives evaluated mitigated the effects of PRRSV 174, PEDV, and SVA in contaminated feed, resulting in improved health and performance.
Canine parvovirus (CPV) is a major enteric pathogen of dogs worldwide that emerged in the late 1970s from a feline parvovirus (FPV)-like ancestral virus. Shortly after its emergence, variant CPVs were generated by acquiring amino-acid (aa) mutations in key capsid residues, associated with biological and/or antigenic changes. This study aimed to identify CPV variants amongst Australian dogs, to gain insights into the evolution of CPV in Australia through phylogenetic analysis of these variants, and to investigate relationships between the disease and vaccination status of dogs from which isolates were collected. CPV VP2 sequences were amplified from 79 faecal samples collected from dogs with parvoviral enteritis at 20 veterinary practices in 5 Australian states. The median age at diagnosis was 4 months (range 1 to 96 months). Only 3.7% of dogs with vaccination histories had completed recommended vaccination schedules, while 49% were incompletely vaccinated and 47.2% were unvaccinated. For the first time, CPV-2b has emerged as the dominant antigenic CPV variant circulating in dogs with parvoviral enteritis in Australia, comprising 54.4% of strains, while CPV-2a and CPV-2 comprised 43.1% and 2.5% of strains. CPV-2c strains were not identified. Analysis of translated VP2 sequences revealed a vast repertoire of aa mutations. Several Australian CPV strains displayed signatures in the VP2 protein typical of Asian CPVs, suggestion introduction of CPV strains from Asia, and/or CPV circulation between Asia and Australia. Strains of CPV were identified containing aa residues typical of FPV at capsid (VP2) key positions, representing reverse mutations or residual mutations retained from CPV-2 during adaptation from an FPV-like ancestor, suggesting that evolutionary intermediates between CPV-2 and FPV are circulating in the field. Similarly, intermediates between CPV-2a-like viruses and CPV-2 were also identified. These findings help inform a better understanding of the evolution of CPV in dogs.
Canine parvovirus type 2 (CPV-2) is a small, single-stranded DNA virus causing fatal hemorrhagic enteritis in dogs. Currently, CPV-2 has been classified into CPV-2a, CPV-2b, and CPV-2c based on genetic variation in the VP2 gene. The CPV-2c variant has become ubiquitous worldwide and gained attention for monitoring parvoviral evolution. In this study, we characterized the full-length genome sequences of CPV-2c isolates obtained from 59 dogs in Vietnam. Molecular analysis revealed that Vietnamese CPV-2c shared a common evolutionary pattern with the Asian CPV-2 clade, which is marked by genetic signature patterns in the structural and nonstructural proteins. In addition, these Vietnamese CPV-2c strains exhibited unique Thr112Ile and Ile447Met mutations in the VP1 and VP2 sequence, respectively. Interestingly, phylogenetic analysis indicated that the mutations of amino acid residues in both the structural and nonstructural genes have contributed to the emergence of a new clade, designated here as the Asia-IV clade. The substitution rates, estimated from a dataset containing 199 sequences over the last 40 years, confirmed that CPV-2 showed a high rate of nucleotide substitution, at about 2.49 x 10-4 nucleotide substitutions per site per year (nt/s/y), with VP1/2 and NS1/2 estimates of 3.06 x 10-4 and 3.16 x 10-4 nt/s/y, respectively. Even though no evidence of genetic recombination in these Vietnamese CPV-2c strains was established, potential positive selection sites were observed in both the structural and nonstructural genes, suggesting the viral evolutionary process has occurred in both the structural and nonstructural proteins. Genetic and evolutionary analysis of the full-length genome sequence is necessary to gain evolutionary insight of CPV-2. Further studies are needed to elucidate the potential role of these observed mutations in the novel Asia-IV clade.
In this study, the digital droplet polymerase chain reaction (ddPCR) was used to quantify circulating bovine papillomavirus (BPV; genus: Deltapapillomavirus) levels in blood samples from 25 healthy cows and 15 cows with chronic enzootic hematuria due to papillomavirus-associated bladder tumors. ddPCR detected the BPV DNA in 95% of all the samples (i.e., in 24 of the healthy cows and 14 of the diseased animals), whereas quantitative real time PCR (qPCR) detected it in only 57.5% of the same blood samples, with the percentage differences between ddPCR and qPCR being statistically significant (P value 0.05), according to the 2 test of Campbell and Richardson. Furthermore, ddPCR detected BPV infections by a single genotype and by multiple genotypes in 37% and 63% of the cows, respectively, whereas qPCR detected these in 16% and 16%, respectively. Of the two assays, ddPCR was the more sensitive and accurate clinical diagnostic tool, allowing the detection of otherwise undetectable BPV genotypes, and consequently, a higher number of BPV co-infections. qPCR failed to detect many BPV co-infections by multiple genotypes. Therefore, ddPCR may be an essential tool for improving diagnostic procedures, allowing the identification of the genotypic distribution of BPV and a better understanding about the territorial divergence, if any, of the BPV prevalence in different areas. No significant differences in the blood viral load estimations were observed between the two animal groups, suggesting that the bloodstream could be a site of primary infection. Finally, as BPV DNA was detected in cows affected by noninvasive urothelial tumors, including papilloma and papillary urothelial neoplasms of low malignant potential, the circulating BPVs appeared to be independent of the status of urothelial neoplasms. Therefore, unlike in humans, circulating BPVs cannot be an actual prognostic marker of urothelial tumors in cows.
Previous research has identified a relationship between climate and occurrence of SARS-CoV and MERS-CoV cases, information that can be used to reduce the risk of infection. Using COVID-19 notification and postcode data from New South Wales, Australia during the exponential phase of the epidemic in 2020, we used time-series analysis to investigate the relationship between 749 cases of locally-acquired COVID-19 and daily rainfall, 9am and 3pm temperature, and 9am and 3pm relative humidity. Lower 9am relative humidity (but not rainfall or temperature) was associated with increased case occurrence; a reduction in relative humidity of 1% was predicted to be associated with an increase of COVID-19 cases by 6.11%. During periods of low relative humidity, the public health system should anticipate an increased number of COVID-19 cases.
Tilapia lake virus (TiLV) is an emerging virus that is rapidly spreading across the world. Over the past 6 years (2014–2020), TiLV outbreaks had been reported in at least 16 countries, spanning three continents, including Asia, Africa, and America. Despite its enormous economic impact, its origin, evolution, and epidemiology are still largely poorly characterised. Here, we report eight TiLV whole genome sequences from Thailand sampled between 2014–2019. Together with publicly available sequences from various regions of the world, we estimated the origin of TiLV to be between 2003–2009, 5–10 years before the first report of the virus in Israel in 2014. Our analyses consistently showed that TiLV started to spread in 2000s, and reached its peak in 2014–2016, matching well with the timing of its first report. From 2016 onwards, the TiLV population declined steadily. This could be a result of herd immunity building up in the fish population, and / or a reflection of a better awareness of the virus coupled with a better and more cautious protocol of Tilapia importation. Despite the fact that we included all publicly available sequences, our analyses revealed long unsampled histories of TiLVs in many countries, especially towards its basal diversification. This result highlights the lack and the need for systematic surveillance of TiLV in fish.
A new pathogenic virus, COVID-19, appeared in 2019, in Wuhan, China, typically causing fever, cough, diarrhea and fatigue and significant mortality. COVID-19 has also shown about 80% genetic similarity to the Severe Acute Respiratory Symptom (SARS) virus, which is already known to be derived from a bat virus. Arterial thrombosis and venous thrombosis, variously attributed to long term patient immobilizations, inflammation, autoimmune reactions or endothelial cell damage to the blood vessels, have also been reported for COVID-19 infections. However, there is another explanation for thrombosis (blood clots) in many patients infected with COVID-19.
African swine fever (ASF) is emerging in Vietnam and poses a continuing severe threat to the swine industry. A histopathological study of clinical samples collected during the August to September 2019 outbreak of ASF was performed to determine the characteristic lesions. We analyzed samples from eight ASFV-infected farms. Histopathological results revealed the characteristic lesions of the acute to the subacute clinical form of ASF. Immunohistochemical results showed ASFV viral antigen distribution in mononuclear cells/macrophage in various organs, hepatocytes, and renal tubular epithelium. Molecular analysis of partial capsid protein 72 gene revealed that ASFV strain from the eight separate outbreaks belonged to genotype II.
Repurposing of existing antiviral drugs, immunological modulators, and supportive therapies represents a promising path toward rapidly developing new control strategies to mitigate the devastating public health consequences of the COVID-19 pandemic. A comprehensive text-mining and manual curation approach was used to comb and summarize the most pertinent information from existing clinical trials. Drugs with previous efficacy against related betacoronaviruses like SARS and MERS were also systematically evaluated as potentially promising candidates for drug repositioning.
New technologies in the field of vaccinology arise as necessity for treatment and control of many diseases. Currently modified live virus and inactivated vaccines used for Bovine Herpesvirus-1 (BoHV-1) have several disadvantages. Previous works for preventive treatment of BoHV-1 with DNA based vaccines have demonstrated the capability to induce humoral and cellular immune response. Nevertheless, it is well known that “naked” DNA induces low immunogenic response. Thus, loading of antigen encoding DNA sequences in liposomal formulations targeting dendritic cell receptors could be a promising strategy to better activate these antigen presenting cells (APC). In this work, DNA based vaccine encoding the truncated version of gD glycoprotein (pCIgD) of BoHV-1 was investigated alone and upon encapsulation on liposomal formulation coated with MANα1-2MAN-PEG-DOPE and LPS from Brucella ovis (pCIgD-Man-L) in mice and cattle assay. Results showed that the use of pCIgD-Man-L was capable to enhance the immune response in both animal models. Significant levels of humoral immunity were achieved when total antibody titers and isotypes were detected in sera and mucosa. For cellular immunity, specific viral lymphoproliferation was detected in the animals inoculated with pCIgD-Man-L. In addition, positively modulation of CD40 molecules on the surface of bovine dendritic cells (DCs) was observed when cells were stimulated and activated with vaccine formulations. When challenge assay was performed, bovines inoculated with pCIgD and liposome decorated with MANα1-2MAN-PEG-DOPE elicited better protection and diminished viral excretion. The results demonstrate the targeting of the MANα1-2MAN coated liposomes toward dendritic cells and their ability to boost the immunogenicity according to an adjuvant effect that results in long-lasting immunity. Liposome decorated with MANα1-2MAN-PEG-DOPE were for the first time tested as DNA based vaccine in cattle as preventive treatment of BoHV-1. These results open up new perspectives for the design of vaccine for the control of bovine rhinotracheitis.
Event-based surveillance (EBS) systems monitor a broad range of information sources to detect early signals of disease emergence, including new and unknown diseases. Following the emergence of a newly identified coronavirus –so-called COVID-19, in humans in December 2019 in Wuhan, China, we conducted a retrospective analysis of the capacity of three Event-Based Systems (EBS) systems (ProMED, HealthMap and PADI-web) to detect early signals of this emergence. We evaluated the changes in the online news vocabulary coinciding with the period before / after the identification of COVID-19, as well as the assessment of its contagiousness and pandemic potential. ProMED was the timeliest EBS, detecting signals one day before the official notification. At this early stage, the specific vocabulary was related to “pneumonia symptoms” and “mystery illness”. Once COVID-19 was identified, the vocabulary changed to virus family and specific COVID-19 acronyms. Our results suggest the three EBS systems are complementary regarding data sources, and all need improvements regarding timeliness. EBS methods should be adapted to the different stages of disease emergence to improve the early detection of future emergence of unknown pathogens.