Staphylococcus spp

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Staphylococcus pseudintermedius infection in the interdigital pad of a dog[1]

Staphylococcus spp are a ubiquitous opportunistic coagulase-positive bacterial pathogen which normally resides on canine skin and within the oropharynx.

The dog is the natural host of Staphylococcus pseudintermedius, but other species of Staphylococcus can cause infections[2].

Species which are pathogenic to dogs include:

  • Staphylococcus intermedius group (SIG)[3]
- Staphylococcus delphini - more commonly found in mustelids[4]
- Staphylococcus intermedius - more commonly found in pigeons
- Staphylococcus pseudintermedius - general skin infections[5], secondary to Demodex spp mites
  • Staphylococcus aureus - exogenous infections, as mainly found in humans[6]
  • Staphylococcus schleiferi[7] (coagulase +ve & -ve) - found in skin, nasal passages, associated with allergic dermatitis[8], otitis externa and pyoderma[9]
  • Staphylococcus lugdunensis[10] - coagulase negative
  • Staphylococcus lentus[11]

Methicillin-resistant S. pseudintermedius (MRSP) strains are reported with increasing frequency in bacterial cultures from cats in Europe, Asia and North America[12]. Resistant bacteria may be transmitted between dogs and the environment and dogs colonised with methicillin-resistant Staphylococcus pseudintermedius may be a source for hospital- and community-acquired infections[13].

Methicillin-resistant S. aureus is also emerging as a problem in veterinary clinics, with recent surveys showing up to 6% of routine dog samples containing this resistant strain[14]. Caution should be exercised in veterinary clinics as once an MRSA strain is introduced into a hospital environment, it can be maintained and spread for extended periods of time[15].

Although some S. pseudintermedius are methicillin resistant and others are methicillin sensitive, there is no real difference in clinical virulence providing the infection is properly diagnosed and appropriate treatment started[16].

It has been shown that cats can carry MRSP for more than a year after a clinically apparent infection. It is therefore prudent to use antimicrobials to which MRSP are sensitive to avoid prolong time of MRSP carriage. Simultaneous sampling of pharynx, perineum, and the corner of the mouth as well as wounds when present is recommended when screening for MRSP[17].

Staphylococcus spp are generally resistant to all β-lactam antibiotics, including cephalosporins, penicillins, ciprofloxacin[18], oxacillin and amoxicillin-clavulanate combinations[19].

S. pseudintermedius, the most common canine pathogen, appears to be sensitive to topical chlorhexidine[20], and parenteral drugs such as ceftiofur[21], enrofloxacin[22], amikacin, rifampicin, chloramphenicol, tetracyclines, linezolid[23], daptomycin, quinupristin/dalfopristin, nitrofurantoin, aminoglycosides, vancomycin, ceftaroline and tigecycline[24].


  1. Leicester skin vet
  2. Bannoehr J & Guardabassi L (2012) Staphylococcus pseudintermedius in the dog: taxonomy, diagnostics, ecology, epidemiology and pathogenicity. Vet Dermatol 23(4):253-266
  3. Kadlec K & Schwarz S (2012) Antimicrobial resistance of Staphylococcus pseudintermedius. Vet Dermatol 23(4):276-282
  4. Guardabassi L et al (2012) Mustelidae are natural hosts of Staphylococcus delphini group A. Vet Microbiol 159(3-4):351-353
  5. Blondeau JM et al (2012) In vitro killing of Escherichia coli, Staphylococcus pseudintermedius and Pseudomonas aeruginosa by enrofloxacin in combination with its active metabolite ciprofloxacin using clinically relevant drug concentrations in the dog and cat. Vet Microbiol 155(2-4):284-290
  6. Sasaki T et al (2012) Population genetic structures of Staphylococcus aureus isolates from cats and dogs in Japan. J Clin Microbiol 50(6):2152-2155
  7. May ER et al(2012) Nasal carriage of Staphylococcus schleiferi from healthy dogs and dogs with otitis, pyoderma or both. Vet Microbiol Jun 25
  8. Cain CL et al (2011) Clinical characterization of Staphylococcus schleiferi infections and identification of risk factors for acquisition of oxacillin-resistant strains in dogs: 225 cases (2003-2009). J Am Vet Med Assoc 239(12):1566-1573
  9. Beck KM et al (2012) Prevalence of meticillin-resistant Staphylococcus pseudintermedius (MRSP) from skin and carriage sites of dogs after treatment of their meticillin-resistant or meticillin-sensitive staphylococcal pyoderma. Vet Dermatol 23(4):369-375
  10. Rook KA et al (2012) Case-control study of Staphylococcus lugdunensis infection isolates from small companion animals. Vet Dermatol 10.1111
  11. Schwendener S & Perreten V (2012) New MLSB Resistance Gene erm(43) in Staphylococcus lentus. Antimicrob Agents Chemother 56(9):4746-4752
  12. Laarhoven LM et al (2011) Longitudinal study on methicillin-resistant Staphylococcus pseudintermedius in households. PLoS One 6(11):e27788
  13. Bergström A et al (2012) Occurrence of methicillin-resistant Staphylococci in surgically treated dogs and the environment in a Swedish animal hospital. J Small Anim Pract 53(7):404-410
  14. Hoet AE et al (2013) Epidemiological Profiling of Methicillin-Resistant Staphylococcus aureus-Positive Dogs Arriving at a Veterinary Teaching Hospital. Vector Borne Zoonotic Dis Mar 8
  15. van Balen J et al (2013) Presence, Distribution, and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Small Animal Teaching Hospital: A Year-Long Active Surveillance Targeting Dogs and Their Environment. Vector Borne Zoonotic Dis Mar 8
  16. Weese JS et al (2012) Factors associated with methicillin-resistant versus methicillin-susceptible Staphylococcus pseudintermedius infection in dogs. J Am Vet Med Assoc 240(12):1450-1455
  17. Windahl U et al (2012) Carriage of methicillin-resistant Staphylococcus pseudintermedius in dogs - a longitudinal study. BMC Vet Res 8:34
  18. Chrobak D et al (2011) Antibiotic resistance of canine Staphylococcus intermedius group (SIG) - practical implications. Pol J Vet Sci 14(2):213-218
  19. Wang Y et al (2012) Methicillin-resistant Staphylococcus pseudintermedius isolated from canine pyoderma in North China. J Appl Microbiol 112(4):623-630
  20. Young R et al (2012) Comparative in vitro efficacy of antimicrobial shampoos: a pilot study. Vet Dermatol 23(1):36-40
  21. Onuma K et al (2012) Antimicrobial resistance of Staphylococcus pseudintermedius isolates from healthy dogs and dogs affected with pyoderma in Japan. Vet Dermatol 23(1):17-22
  22. Blondeau JM et al (2012) In vitro killing of Escherichia coli, Staphylococcus pseudintermedius and Pseudomonas aeruginosa by enrofloxacin in combination with its active metabolite ciprofloxacin using clinically relevant drug concentrations in the dog and cat. Vet Microbiol 155(2-4):284-290
  23. Rubin JE & Chirino-Trejo M (2011) Antimicrobial susceptibility of canine and human Staphylococcus aureus collected in Saskatoon, Canada. Zoonoses Public Health 58(7):454-462
  24. Papich MG et al (2012) Selection of antibiotics for meticillin-resistant Staphylococcus pseudintermedius: time to revisit some old drugs? Vet Dermatol 23(4):352-360