Warren S. Joseph, DPM, FIDSA Roxborough Memorial Hospital, Phila., PA

 Deep soft tissue & Bone cultures grew MSSA & Group B Streptococcus  Patient initially on Vanco + pip/tazo  Given these bugs…what drug do you choose?  Cephalexin

 A marked decrease in patients presenting with MRSA  An increase in ESBL/KPC caused DFI  The approval and release of ceftaroline  The revised IDSA DFI Guidelines

“Aerobic gram-positive cocci (especially Staphylococcus aureus) are the predominant pathogens in diabetic foot infections. Patients who have chronic wounds or who have recently received antibiotic therapy may also be infected with gram-negative rods, and those with ischemia or gangrene may have obligate anaerobes.” CID Oct 1, 2004

Anti-Staph and Strep antibiotic  May be true in mild infection but no definitive data  Polymicrobial flora may worsen prognosis  Caution in severe infection and in osteomyelitis Staphylococcus aureus Beta-haemolytic Strep EnterobacteriaceaeAnaerobes Commensal gram-positive cocci Slide Courtesy of A. Berendt, MD

IDSA Mild (po)  ASOC  Amoxicillin/clavulanic acid  Clindamycin  Oral PRP Moderate/Severe  Β-l actam/ β-l actamase inhibitor compound  Ertapenem  Cefazolin  Clindamycin (IV/PO)  Vancomycin

NEJM Jan 2009 THE ROLE OF HANDWASHING IN THE SPREAD of MRSA

Mild  Later generation tetracycline (PO) Minocycline Doxycycline  TMP/SMX  Clindamycin (+/-) Moderate/Severe  Linezolid (IV/PO)  Vancomycin (IV)  Daptomycin (IV)  Tigecycline (IV)  Ceftaroline (IV)

 An increasing clinical problem  “Staph aureus with reduced susceptibility to vancomycin”  aka “MIC Creep” Difficult to detect MIC on the rise from 0.5 » 1.0 » 2.0 µg Have been associated with Tx failures  PLEASE – Look at your vancomycin MIC if considering its use against MRSA!

Vancomycin MIC on the Move Wang G et al. J Clin Microbiol. 2006;44: % of Isolates MIC=minimum inhibitory concentration.

“If you show a vancomycin MIC against MRSA of >1µg/ml you can not achieve a level of vancomycin that is high enough to be both safe and effective. You should use an alternative agent” paraphrasing Robert Moellering, MD, ICAAC 2009

Courtesy of Lee Rogers, DPM

 This one is easy…pretty much anything you use for Staphylococcus will be active against Group B Streptococcus

 Extended Spectrum β -lactamases (ESBL) Increasing in E. coli, Proteus mirablis & Kleb pneumo along with other gnr Resistant to most penicillins, cephalosporins and β lactamase inhibitor compounds Still susceptible to most carbapenems and tigecycline  Carbapenemase producing gnr (KPC) Not yet as common as ESBL As name implies, resistant to carbapenems  NDM-1  Do we need to concern ourselves??

 Do we really need to treat it? Options  Ciprofloxacin (PO/IV)  Ceftazidime (IV)  Cefepime (IV)  Aztreonam (IV) +/- Aminoglycoside  Other quinolone  Piperacillin/tazobactam *

 “Head of the Snake” principle  Consider empiric “De-escalation” therapy depending on local MRSA prevalence  Watch your vancomycin MICs for “creep”  Be aware of ESBLs and KPCs in your hospital (speak with your IC specialist)  Be alert for “Pseudomonophobia”