Characterization of the biofilm forming ability of Staphylococcus pseudintermedius from dogs

Abstract

BackgroundStaphylococcus pseudintermedius is an opportunistic pathogen of dogs and has emerged as a leading cause of skin, wound and surgical site infections worldwide. Methicillin resistance is common and clinical infections as a result of methicillin-resistant S. pseudintermedius (MRSP) pose a clinical challenge. In other staphylococci, biofilm formation has been shown to be a virulence factor for infection, however, it has received little attention in S. pseudintermedius. The objectives of this study were to evaluate the biofilm forming ability of clinical isolates of S. pseudintermedius obtained from dogs using phenotypic and genotypic techniques.Results96% (136/140) of S. pseudintermedius isolates were classified as strong or moderate biofilm producers, with the majority of isolates being able to produce biofilm. There was no difference in biofilm formation between MRSP and MSSP (p=0.8), amongst isolates from clinical infections compared with isolates obtained from colonized dogs (p=0.08), and between isolates from sequence type (ST) 71 and ST 68 (P=0.09). icaA was detected in 77.9% (109/140) of isolates and icaD was detected in 75.7% (106/140) of isolates. Scanning electron microscopic evaluation of S. pseudintermedius biofilm production revealed aggregates of cocci and irregularly produced extracellular polymeric matrix.ConclusionThe majority of S. pseudintermedius isolates evaluated in this study were able to produce biofilm and this may be an important virulence factor in the rapid emergence of this bacterium in veterinary hospitals worldwide. Further study into the mechanisms of biofilm formation by S. pseudintermedius is warranted.

Comparative RNA-seq-Based Transcriptome Analysis of the Virulence Characteristics of Methicillin-Resistant and -Susceptible Staphylococcus pseudintermedius Strains Isolated from Small Animals

“…Yet, the study failed to find differences in the biofilm formation between MRSP and MSSP isolates. The number of MSSP isolates that was studied was low, and the authors suggested that further experiments with a larger number of isolates were warranted (6). By using a larger set of isolates, we observed that biofilm production in the BHIB and BHIB-1% glucose media was significantly higher in MSSP than in MRSP isolates.…”

“…This capacity might further complicate the treatment of already challenging infections due to the decrease in effectiveness of antimicrobials on biofilms (5). In one study, all S. pseudintermedius isolates produced biofilms, suggesting that biofilm production might be essential for the pathogenicity of S. pseudintermedius (6). Yet, the study failed to find differences in the biofilm formation between MRSP and MSSP isolates.…”

“…The frequent carriage of prophages in the MRSP sequence type 71 (ST71) and ST68 genomes suggested they have a role in the fitness of MRSP and that the predominant transfer of genetic material in these isolates is through bacteriophage transduction, rather than plasmid conjugation, as happens in methicillin-resistant Staphylococcus aureus (MRSA) (1). MRSP isolates are able to produce biofilm, and MRSP ST71 isolates, in particular, are better biofilm producers than other MRSP clones (5,6). The icaA gene can be significantly upregulated in biofilm samples, suggesting a role in the biofilm production by S. pseudintermedius (7).…”

“…The icaA gene can be significantly upregulated in biofilm samples, suggesting a role in the biofilm production by S. pseudintermedius (7). The ability to form biofilm may play an important role in the pathophysiology of bacterial infections and can be related to survival and persistence of S. pseudintermedius, namely, MRSP, in the environment (5,6). The MRSP ST71 isolates also show greater adherence to corneocytes than MRSP non-ST71 and methicillinsusceptible S. pseudintermedius (MSSP) isolates, and thus it has been suggested that the enhanced adherence of ST71 might be a factor contributing to the epidemiological success of this MRSP lineage (2).…”

Emergence of biofilm-producingStaphylococcus pseudintermediusisolated from healthy dogs in South Korea

“…Among staphylococci, Staphylococcus epidermidis is widely known as the predominant cause of biofilminduced catheter-and medical device-related sepsis in humans (O'Gara & Humphreys 2001). Recently, several studies reported that MRSP, especially sequence type (ST) 71, also has an ability to produce biofilms, suggesting the necessity of investigation for the prevalence of biofilm-producing S. pseudintermedius in veterinary practices (Dicicco et al 2012;Osland et al 2012;Singh et al 2013). In South Korea, several studies have reported a high prevalence of MRSP in dogs Yoon et al 2010).…”