Carriage ofStaphylococcus schleiferifrom canine otitis externa: antimicrobial resistance profiles and virulence factors associated with skin infection

Abstract

The recent emergence of Staphylococcus schleiferi in dogs with otitis externa or skin and soft tissue infections has become a significant zoonotic issues. In the current study, we investigated 1) the carriage rates of S. schleiferi among major staphylococci in healthy dogs and dogs with otitis externa, 2) antibiotic susceptibility profiles of S. schleiferi, particularly methicillin resistance (MR), and 3) virulence factors associated with skin and soft tissue infections such as ability to form biofilm, resistance to cationic antimicrobial peptides (CAMPs), and carriage of staphylococcal enterotoxin genes. Among the 21 S. schleiferi isolates, 5 isolates (24%) were determined to be methicillin-resistant (MRSS). Staphylococcal cassette chromosome mec (SCC mec ) typing revealed the presence of SCC mec type V in 4 MRSS isolates and type VII in one MRSS. Higher levels of antibiotic resistance, especially multidrug resistance, were observed in MRSS isolates compared to the methicillin-susceptible S. schleiferi (MSSS) isolates. In addition, MRSS isolates exhibited enhanced ability to form biofilm under static condition and all the 5 MRSS isolates carried three or more enterotoxin genes. However, there were no significant differences in resistance to CAMPs between MRSS and MSSS isolates. These findings suggest that coagulase-negative S. schleiferi is becoming more prevalent in canine otitis externa cases. Our results also highlight the presence of multidrug-resistant MRSS isolates with enhanced biofilm production and carriage of multiple enterotoxins.

Prevalence of Antimicrobial Resistance in Bacterial Isolates from Dogs and Cats in a Veterinary Diagnostic Laboratory in Colombia from 2016–2019

“…With regards to skin and ear infections and consistent with other studies, Staphylococcus coagulase-positive (CoPS), and in particular Staphylococcus pseudointermedius, was the most common organism isolated [8][9][10][11]. This was followed by Staphylococcus coagulase-negatives (CoNS), which other studies have identified mostly as S. schleiferi.…”

“…They also showed that multi-drug resistant isolates occurred almost exclusively in CoNS for cats, but it was almost equally distributed between the CoNS and CoPS groups for dogs. Thus, the clinical significance of CoNS may not only be as opportunistic pathogens [ 8 ], but also as clear potential reservoirs of antimicrobial resistance genes that can be transferred to CoPS. Except for the skin, we found a much higher prevalence (6–10 fold) of CoPS than CoNS in samples from ears, wounds, nasal cavity, and abscesses; whether this implies a clinically relevant association is unknown, as the pathogenicity of CoNS has not been clearly established.…”

Identification of hemolysin encoding genes and their association with antimicrobial resistance pattern among clinical isolates of coagulase-negative Staphylococci

“…Our results showed that the frequency of hemolytic agent genes of hla, hlb, hld were higher in cefoxitin resistant isolates compared to susceptible ones. [41][42][43].…”

Virulence and Antimicrobial Resistance in Canine Staphylococcus spp. Isolates

“…The coagulase-positive Staphylococcus pseudointermedius is the most detected species in both healthy and sick dogs, and it is assumed that it is host-adapted [ 9 ]. Though with a lower detection rate, other CoPS and CoNS can be isolated and cause diseases in dogs: Staphylococcus aureus , Staphylococcus schleiferi , Staphylococcus epidermidis , Staphylococcus haemolyticus , Staphylococcus saprophyticus , Staphylococcus sciuri , and Staphylococcus warneri [ 10 , 11 , 12 ]. The exact arrangement of different Staphylococcus species as saprophytic, commensal, opportunistic, or pathogens for dogs is still under evaluation.…”

“…Many studies have been focused on the discovery of some bacterial or host factors that could be at the basis of disease development, even if a mix of these factors are probably involved [ 1 , 7 , 9 , 13 ]. Regarding the bacterial side, different virulence factors have been detected in strains isolated from dogs, in particular from skin lesions, including different types of exfoliative toxins, leucocidins, superantigens, enterotoxins, invasion enzymes, and biofilm producers [ 10 , 11 , 14 , 15 , 16 ].…”