Ecological features, pathogenic properties, and role of Staphylococcus intermedius group representatives in animal and human infectious pathology

Investigation on biofilm composition and virulence traits of S. pseudintermedius isolated from infected and colonized dogs

Staphylococcus pseudintermedius, which is part of the skin microbiome of dogs, causes a variety of opportunistic infections. These infections may become more difficult to treat due to the formation of biofilm. The capacity of S. pseudintermedius to form biofilm, as well as the associated genes, has not been elucidated. This study evaluated the production and composition of S. pseudintermedius biofilm. Samples were collected from both infected dogs and asymptomatic dogs. Isolates were identified using mass spectrometry and Multiplex-PCR. Biofilm production and composition were assessed using a quantitative microtiter plate assay. The presence of ica operon genes and sps genes was investigated using conventional PCR. The investigation of Agr type and virulence genes was conducted in silico on 24 sequenced samples. All strains could produce strong biofilms, with most of the isolates presenting a polysaccharide biofilm. 63.6% of the isolates carried the complete ica operon (ADBC). All samples showed the presence of the genes spsK, spsA, and spsL, while the distribution of other genes varied. Agr type III was the most prevalent (52.2%). All sequenced samples carried the cytotoxins hlb, luk-S, luk-F, as well as the exfoliative toxins siet and se_int. No isolate displayed other exfoliative toxins. Only LB1733 presented a set of different enterotoxins (sea, seb, sec_canine, seh, sek, sel, and seq). Our findings suggest that S. pseudintermedius is a strong producer of biofilm and carries virulence genes.

Hybrid Assembly from a Pathogenic Methicillin- and Multidrug-Resistant Staphylococcus pseudintermedius Strain Isolated from a Case of Canine Otitis in Spain

Here we report the genome assembly, using a hybrid approach with Illumina and Nanopore sequencing, of a pathogenic Staphylococcus pseudintermedius strain isolated from a case of canine otitis. Genome assembly confirmed the antimicrobial resistance profile (disk diffusion testing) with specific genes and mutations.