First there was Staphylococcus intermedius.

What is Staphylococcus pseudintermedius Andrew Hillier BVSc, MACVSc, Dipl. ACVD The Ohio State University First there was Staphylococcus intermedius. Hillier Cremona March 2011 1

Then came Staphylococcus schleiferi. Then came Staphylococcus schleiferi. Hillier Cremona March 2011 2

Then came Staphylococcus schleiferi. Then came Staphylococcus schleiferi. Hillier Cremona March 2011 3

Then came Staphylococcus schleiferi. And finally Staphylococcus pseudintermedius Hillier Cremona March 2011 4

And finally Staphylococcus pseudintermedius And finally Staphylococcus pseudintermedius Hillier Cremona March 2011 5

And finally Staphylococcus pseudintermedius Hillier Cremona March 2011 6

DOGS S. intermedius = S. pseudintermedius Staphylococci causing pyoderma S. pseudintermedius is the primary pathogen S. aureus S. schleiferi S. schleiferi coagulans? S. intermedius Pathogen of wild pigeons Coagulase Staph. S. epidermidis S. sciuri S. schleiferi schleiferi? Hillier Cremona March 2011 7

Differentiating the Staph. species Coagulase test (+ or ) Colony characteristics S. aureus vs. S. pseudintermedius vs. S. schleiferi S. pseudintermedius vs. S. schleiferi coagulans Automated ID systems?? Specific biochemical tests VP test and sugar fermentation Molecular techniques (PCR) IS THIS IMPORTANT? WHO CARES? Speciation: METHICILLIN RESISTANCE Species does not alter AMD treatment BUT, species will alter How methicillin resistance is interpreted in vitro Public health implications MRSA significant human pathogen MRSP + MRSS rare human pathogen Infection control measures Hillier Cremona March 2011 8

Staphylococci at carriage sites Primary carriage sites Staphylococci at carriage sites Other (secondary) carriage sites Hillier Cremona March 2011 9

Dogs with pyoderma: Staphylococci at carriage sites Dogs with pyoderma: larger populations at nasal and anal sites than normal dogs Hillier Cremona March 2011 10

AJVR 67 (8) 2006; 1337 1346 40 dogs with superficial bacterial folliculitis Bacterial culture from: 3 pustules 3 carriage sites Anal Nasal Unaffected axillary skin PFGE 6 S. intermedius isolates Site ST P1 P2 P3 AR AX NM ST Lane 1 2 3 4 5 6 7 8 Lanes 3, 5, 6, and 7 had the same PFGE pattern. Lanes 2 and 4 had different PFGE patterns. Hillier Cremona March 2011 11

Dogs with pyoderma: Staph. at carriage sites genotypically related to Staph. in pustules (94.4% of dogs) (Pinchbeck et al, 2006) Hillier Cremona March 2011 12

Staphylococci at carriage sites following treatment of superficial pyoderma: Hillier et al, NAVDF April 2007 18 dogs treated with cefpodoxime proxetil (Simplicef ) to resolution of infection 3 carriage sites cultured before and immediately after antibiotic therapy Were Staph. still present at carriage sites after antibiotics? If so, were they the same strain? Post resolution of pyoderma: Staph. at carriage site 14/18 dogs Same Staph. as in pustules pretreatment 7/18 dogs (Hillier et al, 2007) Hillier Cremona March 2011 13

Post resolution of pyoderma: Anal mucosa more often positive culture than other carriage sites posttreatment (Hillier et al, 2007) Dogs with pyoderma with Staphylococci at carriage sites Hillier Cremona March 2011 14

Dogs with pyoderma with Staphylococci at carriage sites 1. Do they keep getting reinfected from carriage sites? 2. Traditionally, prevent recurrence by controlling underlying disease (allergy etc.) 3. Should we be treating carriage sites as well as the active infection? Hillier Cremona March 2011 15

Staph. Virulence Hillier Cremona March 2011 16

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