METHODS: Specimens were further studied with universal and species-specific CoV and CCoV 1-step RT-PCR assays, and viral isolation was performed in A72 canine cells. Complete genome sequencing was conducted using the Sanger method.
RESULTS: Two of 8 specimens contained sufficient amounts of CCoVs as confirmed by less-sensitive single-step RT-PCR assays, and 1 specimen demonstrated cytopathic effects in A72 cells. Complete genome sequencing of the virus causing cytopathic effects identified it as a novel canine-feline recombinant alphacoronavirus (genotype II) that we named CCoV-human pneumonia (HuPn)-2018. Most of the CCoV-HuPn-2018 genome is more closely related to a CCoV TN-449, while its S gene shared significantly higher sequence identity with CCoV-UCD-1 (S1 domain) and a feline CoV WSU 79-1683 (S2 domain). CCoV-HuPn-2018 is unique for a 36-nucleotide (12-amino acid) deletion in the N protein and the presence of full-length and truncated 7b nonstructural protein, which may have clinical relevance.
CONCLUSIONS: This is the first report of a novel canine-feline recombinant alphacoronavirus isolated from a human patient with pneumonia. If confirmed as a pathogen, it may represent the eighth unique coronavirus known to cause disease in humans. Our findings underscore the public health threat of animal CoVs and a need to conduct better surveillance for them.
OBJECTIVES: This study investigated the status of Bartonella infection in cats from eight (n = 8) shelters by molecular and serological approaches, profiling the CD4:CD8 ratio and the risk factors associated with Bartonella infection in shelter cats.
METHODS: Bartonella deoxyribonucleic acid (DNA) was detected through polymerase chain reaction (PCR) targeting 16S-23S rRNA internal transcribed spacer gene, followed by DNA sequencing. Bartonella IgM and IgG antibody titre, CD4 and CD8 profiles were detected using indirect immunofluorescence assay and flow cytometric analysis, respectively.
RESULTS: B. henselae was detected through PCR and sequencing in 1.0% (1/101) oral swab and 2.0% (1/50) cat fleas, while another 3/50 cat fleas carried B. clarridgeiae. Only 18/101 cats were seronegative against B. henselae, whereas 30.7% (31/101) cats were positive for both IgM and IgG, 8% (18/101) cats had IgM, and 33.7% (34/101) cats had IgG antibody only. None of the eight shelters sampled had Bartonella antibody-free cats. Although abnormal CD4:CD8 ratio was observed in 48/83 seropositive cats, flea infestation was the only significant risk factor observed in this study.
CONCLUSIONS: The present study provides the first comparison on the Bartonella spp. antigen, antibody status and CD4:CD8 ratio among shelter cats. The high B. henselae seropositivity among shelter cats presumably due to significant flea infestation triggers an alarm of whether the infection could go undetectable and its potential transmission to humans.