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Despite extensive characterisation of uropathogenic Escherichia coli (UPEC) causing urinary tract infections (UTIs), the genetic background of non-urinary extraintestinal pathogenic E. coli (ExPEC) in companion animals remains inadequately understood. In this study, we characterised virulence traits of 104 E. coli isolated from canine pyometra (n = 61) and prostatic abscesses (PAs) (n = 38), and bloodstream infections (BSIs) in dogs (n = 2), and cats (n = 3). A stronger association with UPEC of pyometra strains in comparison to PA strains was revealed. Notably, 44 isolates exhibited resistance to third-generation cephalosporins and/or fluoroquinolones, 15 were extended-spectrum ß-lactamase-producers. Twelve multidrug-resistant (MDR) strains, isolated from pyometra (n = 4), PAs (n = 5), and BSIs (n = 3), along with 7 previously characterised UPEC strains from dogs and cats, were sequenced. Genomic characteristics revealed that MDR E. coli associated with UTIs, pyometra, and BSIs belonged to international high-risk E. coli clones, including sequence type (ST) 38, ST131, ST617, ST648, and ST1193. However, PA strains belonged to distinct lineages, including ST12, ST44, ST457, ST744, and ST13037. The coreSNPs, cgMLST, and pan-genome illustrated intra-clonal variations within the same ST from different sources. The high-risk ST131 and ST1193 (phylogroup B2) contained high numbers of ExPEC virulence genes on pathogenicity islands, predominating in pyometra and UTI. Hybrid MDR/virulence IncF multi-replicon plasmids, containing aerobactin genes, were commonly found in non-B2 phylogroups from all sources. These findings offer genomic insights into non-urinary ExPEC, highlighting its potential for invasive infections in pets beyond UTIs, particularly with regards to high-risk global clones., (© 2024. The Author(s).)

Objective: In the literature, the BRAF mutation is reported to have been identified in 80 % of the examined canine prostate carcinomas (PCa). The objectives of this study were to test for the BRAF mutation in canine PCa in our cohort of canine patients, to determine the specificity and sensitivity of the test for this mutation, as well as to identify the association between the presence of the BRAF mutation and the histologic picture of PCa. Moreover, the method was to be established in cytology samples., Material and Methods: Biopsy samples (n = 70) and cytologic slides (n = 17) of 87 dogs with prostatic diseases were selected. Prostatic diseases were classified according to the literature as benign prostate hyperplasia (BPH, n = 22), prostatitis (n = 14), squamous cell metaplasia of the prostate (PM, n = 2), atrophy following castration (n = 3) und PCa (n = 46; histologic diagnosis n = 35, cytologic diagnosis n = 11). Additionally, the Gleason score was determined for each PCa. DNA isolation was performed using commercially available kits. Exon 15 was examined using the TaqMan ® SNP assay. The specificity and sensitivity of the test were calculated., Results: A Gleason score of 6 and 7 was shown in 1 PCa each, in 33 cases the score ranged between 8 and 10. Sufficient amount of good-quality DNA was isolated from all samples. 28/46 PCa were tested positive for the BRAF mutation (sensitivity 61 %). The BRAF mutation was not evident in any of the dogs with BPH, prostatitis, PM or atrophy (specificity 100 %). PCa positive for the BRAF mutation exhibited a significantly higher Gleason score (p = 0.002) in comparison to PCa without this mutation., Conclusion and Clinical Relevance: BRAF mutation analysis is a highly specific method and may aid in confirming the diagnosis of PCa in histologically and cytologically questionable cases. PCa positive for BRAF mutation exhibited more criteria of malignancy than PCa without this mutation. The clinical, therapeutic, and prognostic relevance of these findings needs to be evaluated by further studies., Competing Interests: Die Autorinnen Grassinger, Aupperle-Lellbach und Erhard arbeiten bei der Firma LABOKLIN GmbH & Co. KG, die die Untersuchung auf die BRAF-Variante V595E kommerziell anbietet., (© Georg Thieme Verlag KG Stuttgart · New York.)