“drugs for bugs 2011” in diabetic foot infections
DESCRIPTION
“Drugs for Bugs 2011” in Diabetic Foot Infections. Warren S. Joseph, DPM, FIDSA Roxborough Memorial Hospital, Phila ., PA www.leinfections.com. Cellulitis & Osteomyelitis (IDSA Severe) Admission 1/31/11. Cellulitis & Osteomyelitis (IDSA Severe) Admission 1/31/11. - PowerPoint PPT PresentationTRANSCRIPT
Warren S. Joseph, DPM, FIDSARoxborough Memorial Hospital, Phila.,
PAwww.leinfections.com
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 Anti-Staph and Strep antibioticantibiotic
May be true in mild infection but no definitive data
Polymicrobial flora may worsen prognosis
Caution in severe infection and in osteomyelitis
Staphylococcus Staphylococcus aureusaureus
Beta-haemolytic Beta-haemolytic StrepStrep
EnterobacteriaceaeEnterobacteriaceae
AnaerobesAnaerobes
Commensal gram-positive cocciCommensal gram-positive cocci
Slide Courtesy of A. Berendt, MD
IDSA Mild (po) ASOC Amoxicillin/clavulanic acid Clindamycin Oral PRPModerate/Severe Β-lactam/β-lactamase 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!
0
10
20
30
40
50
60
70
80
90
2000 2001 2002 2003 2004
MIC ≤0.5 MIC=1 MIC ≥2
Wang G et al. J Clin Microbiol. 2006;44:3883-3886.
% o
f Is
ola
tes
79.9
19.9
0.2 0.2 0.3 0.2 0.8
80.9
18.9
64.6
35.1
60.1
39.7
70.4
28.8
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”