Expression of cannabinoid and cannabinoid-related receptors in the oral mucosa of healthy cats and cats with chronic gingivostomatitis.

OBJECTIVES: Feline chronic gingivostomatitis (FCGS) is an oral disease. Cats with FCGS experience intense oral pain. Some cats remain refractory to current therapies based on dental extraction and adjuvant medical treatment; it is therefore necessary to investigate alternative therapeutic targets involved in inflammatory mechanisms and pain, namely the endocannabinoid system (ECS). The present study investigated the expression of cannabinoid receptors type 1 (CB1R) and 2 (CB2R), and cannabinoid-related receptors G protein-coupled receptor 55 (GPR55), transient receptor potential ankyrin 1 (TRPA1) and serotonin 1a receptor (5-HT1aR), in the oral mucosa of healthy cats to determine whether there was altered expression and distribution in cats with FCGS. METHODS: Samples of caudal oral mucosa were collected from eight control cats (CTRL cats) and from eight cats with FCGS (FCGS cats). Tissue samples were processed using an immunofluorescence assay with cat-specific antibodies, and the immunolabelling of the receptors studied was semiquantitatively evaluated. RESULTS: The mucosal epithelium of the CTRL cats showed CB1R, TRPA1 and 5-HT1aR immunoreactivity (IR), while CB2R and GPR55 IR were generally not expressed. In the CTRL cats, the subepithelial inflammatory cells expressed CB2R, GPR55 and 5-HT1aR IR. In the FCGS cats, all the receptors studied were markedly upregulated in the epithelium and inflammatory infiltrate. CONCLUSIONS AND RELEVANCE: Cannabinoid and cannabinoid-related receptors are widely expressed in the oral mucosa of healthy cats and are upregulated during the course of FCGS. The presence of cannabinoid and cannabinoid-related receptors in healthy tissues suggests the possible role of the ECS in the homeostasis of the feline oral mucosa, while their overexpression in the inflamed tissues of FCGS cats suggests the involvement of the ECS in the pathogenesis of this disease, with a possible role in the related inflammation and pain. Based on the present findings, ECS could be considered a potential therapeutic target for patients with FCGS.

Whole-genome sequencing of a CTX-M-11-encoding and quinolone-non-susceptible Klebsiella pneumoniae ST194 isolate from a hospitalised dog in Greece.

OBJECTIVES: The emergence and spread of transferable ß-lactamases among Enterobacteriaceae is a major problem both to human and veterinary medicine and is an important contributing factor to the development of multidrug-resistant bacterial isolates. In the present study, whole-genome sequencing of a Klebsiella pneumoniae isolate (LKP817909) resistant to first- and second-generation cephalosporins and non-susceptible to fluoroquinolones, isolated from a urine sample of a hospitalised dog, was performed. METHODS: Genome sequencing was performed on an Illumina MiniSeq Sequencing System. Multilocus sequence typing (MLST) was performed using a BLAST-based approach, whereas antimicrobial resistance genes and plasmid replicons were identified by ResFinder and PlasmidFinder, respectively. The Rapid Annotation using Subsystem Technology (RAST) server v.2.0 was used for genome annotation. RESULTS: Data analyses revealed the complete resistome of isolate LKP817909, which included the cefotaximase-München-11 (CTX-M-11) extended-spectrum ß-lactamase together with 11 other resistance genes. Ten resistance genes were located on plasmids and two on the chromosome. CONCLUSIONS: To the best of our knowledge, this is the first detection of a CTX-M-11-producing K. pneumoniae isolated from a canine. The whole genome sequence of the isolate has been deposited at GenBank to serve as a future reference.

Substance P and the neurokinin-1 receptor expression in dog ileum with and without inflammation.

In the gastrointestinal tract, the tachykinin Substance P (SP) is involved in motility, fluid and electrolyte secretion, and blood flow and regulation of immunoinflammatory response. SP exerts its biological activity on target cells by interacting mainly with the neurokinin-1 receptor (NK1R). The present study aims to quantify the percentage of SP-immunoreactive (SP-IR) enteric neurons and the density of SP-IR nerve fibers in the ileum of control dogs (CTRL-dogs; n=7) vs dogs with spontaneous ileal inflammation (INF-dogs; n=8). In addition, the percentage of enteric neurons bearing NK1R, and nitrergic neurons (nNOS-IR) expressing NK1R immunoreactivity were evaluated in both groups. The percentages of SP-IR neurons were similar in CTRL- and INF-dogs, in either the myenteric (MP) (15±8% vs. 16±7%, respectively) and submucosal plexus (SMP) (26±7% vs. 24±14%, respectively). In INF-dogs, the density of SP-IR mucosal nerve fibers showed a trend to decrease (P=0.07). Myenteric neurons of CTRL- and INF-dogs expressed similar percentages of NK1R-immunoreactivity (39±5% vs. 38±20%, respectively). Submucosal NK1R-IR neurons were occasionally observed in a CTRL-dog. MP nitrergic neurons bearing NK1R showed a trend to decrease in INF-dogs vs. CTRL- dogs (41±22% vs. 65±10%, respectively; P=0.11). In INF-dogs, muscle cells and immune cells overexpressed NK1R immunoreactivity. These findings should be taken as a warning for possible intestinal motility disorders, which might occur during administration of NK1R-antagonist drugs. Conversely, the strong expression of NK1R immunoreactivity observed in muscle and mucosal immune cells of inflamed tissues may provide a rationale for the use of NK1R antagonist drugs in the treatment of intestinal inflammation.