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Feline respiratory disease complex (FRDC) is a highly prevalent syndrome in cats that often result in fatal outcomes. FRDC etiology is complex, and often, multiple viral and bacterial pathogens are simultaneously associated with disease causation. There is limited information about the role of co-infections in pathogenesis and the current prevalence of pathogens in North America. We aimed to conduct a study using technical advances in molecular diagnosis and statistical modeling analysis to elucidate the occurrence of pathogens and how co-infections affect disease severity. We attained information from three diagnostic laboratories in North America regarding the occurrence of Bordetella bronchiseptica, Chlamydia felis, Mycoplasma, Felid alphaherpesvirus 1 (FeHV-1), feline calicivirus (FCV), and influenza A, along with age, seasonality, sex, and clinical signs. We also evaluated the role of co-infections in disease severity. These pathogens were also investigated in clinically normal cats (control). The most detected pathogens were Mycoplasma, FCV, and FeHV-1. Most pathogens were detected in the control group, highlighting the challenge of interpreting positive testing results. Co-infections of Mycoplasma and FCV, as well as Mycoplasma and FeHV-1, were important predictors of disease severity. Age, sex, and season had a minor impact on pathogen occurrence. This study provides new insights into FRDC and underlines the relevance of diagnostic panels to screen for a range of pathogens, providing knowledge for timely diagnosis and therapeutic interventions. [ABSTRACT FROM AUTHOR]

Canine respiratory coronavirus (CRCoV) is one of the main causative agents of canine infectious respiratory disease (CIRD), an illness whose epidemiology is poorly understood. We assessed the prevalence, risk factors, and genetic characterization of CRCoV in privately owned dogs in the Southeastern United States. We PCR-screened 189 nasal swabs from dogs with and without CIRD clinical signs for 9 CIRD-related pathogens, including CRCoV; 14% of dogs, all diagnosed with CIRD, were positive for CRCoV, with a significantly higher rate of cases in younger dogs and during warmer weather. Notably, the presence of CRCoV, alone or in coinfection with other CIRD pathogens, was statistically associated with a worse prognosis. We estimated a CRCoV seroprevalence of 23.7% retrospectively from 540 serum samples, with no statistical association to dog age, sex, or season, but with a significantly higher presence in urban counties. Additionally, the genomes of 6 CRCoVs were obtained from positive samples using an in-house developed targeted amplicon-based approach specific to CRCoV. Subsequent phylogeny clustered their genomes in 2 distinct genomic groups, with most isolates sharing a higher similarity with CRCoVs from Sweden and only 1 more closely related to CRCoVs from Asia. We provide new insights into CIRD and CRCoV epidemiology in the Southeastern United States and further support the association of CRCoV with more severe cases of CIRD. Additionally, we developed and successfully tested a new amplicon-based approach for whole-genome sequencing of CRCoV that can be used to further investigate the genetic diversity within CRCoVs. [ABSTRACT FROM AUTHOR]

A mortality event among recently captured feral donkeys (Equus asinus) occurred in south-central Utah in 2016. The deaths were sporadic, and clinical signs were indicative of respiratory disease, likely associated with an infectious etiology. Ten of 13 donkeys autopsied had moderate-to-severe interstitial fibrosing pneumonia, and one had pyogranulomatous pneumonia. Consensus PCRs directed toward the DNA polymerase and DNA packaging terminase subunit 1 for herpesviruses were performed followed by sequencing of the PCR amplicons and phylogenetic analysis. Asinine herpesvirus 4 (AsHV4) and 5 (AsHV5) were consistently identified in lung tissues of affected donkeys. No other herpesviruses were identified, and herpesviral DNA was not detected in lung tissues of 2 donkeys without evidence of respiratory disease. The detection of asinine gammaherpesviruses may have been associated with the lesions described. AsHV4 and AsHV5 have been reported in previous studies as novel gammaherpesviruses based on sequences obtained from donkeys with interstitial pneumonia and marked syncytial cell formation. Our findings suggest that the association of asinine gammaherpesviruses with respiratory conditions in equids deserves further attention. [ABSTRACT FROM AUTHOR]

The Pasteurellaceae family has been associated with fatal diseases in numerous avian species. Several new taxa within this family, including Bisgaard taxon 40, have been recently described in wild birds, but their genomic characteristics and pathogenicity are not well understood. We isolated Bisgaard taxon 40 from four species of seabirds, including one sampled during a mass, multi-species mortality event in Florida, United States. Here, we present a comprehensive phenotypic and genetic characterization of Bisgaard taxon 40 and comparative genomic analysis with reference strains from the Pasteurellaceae family, aiming at determining its phylogenetic position, antimicrobial susceptibility profile, and identifying putative virulence factors. In silico multilocus sequence-based and whole-genome-based phylogenetic analysis clustered all Bisgaard taxon 40 strains together on a distinct branch separated from the other members of the Pasteurellaceae family, indicating that Bisgaard taxon 40 could represent a new genus. These findings were further supported by protein similarity analyses using the concatenation of 31 conserved proteins and other taxonomic approaches such as the percentage of conserved protein test. Additionally, several putative virulence factors were identified, including those associated with adhesion (capsule, ompA , ompH) and colonization (exbD , fur , galU , galE , lpxA , lpxC , and kdsA) of the host and a cytolethal distending toxin (cdt), which may have played a role in disease development leading to the mortality event. Considerably low minimum inhibitory concentrations (MICs) were found for all the drugs tested, in concordance with the absence of antimicrobial resistance genes in these genomes. The novel findings of this study highlight genomic and phenotypic characteristics of this bacterium, providing insights into genome evolution and pathogenicity. We propose a reclassification of these organisms within the Pasteurellaceae family, designated as Mergibacter gen. nov., with Mergibacter septicus sp. nov. as the type species. The type strain is Mergibacter septicus A25201T (=DSM 112696). [ABSTRACT FROM AUTHOR]