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198 SEcTioN ii Microbiology ` microbiology—aNtimicrobials Microbiology ` microbiology—aNtimicrobials

Antimicrobial cliNical sceNario meDicatioN
prophylaxis Exposure to meningococcal infection Ceftriaxone, ciprofloxacin, or rifampin

High risk for endocarditis and undergoing Amoxicillin
surgical or dental procedures
History of recurrent UTIs TMP-SMX
Malaria prophylaxis for travelers Atovaquone-proguanil, mefloquine, doxycycline,
primaquine, or chloroquine (for areas with
sensitive species)

Pregnant woman carrying group B strep Intrapartum penicillin G or ampicillin
Prevention of gonococcal conjunctivitis in Erythromycin ointment on eyes
newborn
Prevention of postsurgical infection due to Cefazolin
S aureus
Prophylaxis of strep pharyngitis in child with Benzathine penicillin G or oral penicillin V
prior rheumatic fever

Prophylaxis in HIV/AIDS patients
cell coUNt ProPHylaXis iNFectioN
CD4 < 200 cells/mm 3 TMP-SMX Pneumocystis pneumonia
CD4 < 100 cells/mm 3 TMP-SMX Pneumocystis pneumonia and toxoplasmosis
CD4 < 50 cells/mm 3 Azithromycin or clarithromycin Mycobacterium avium complex

Treatment of highly MRSA: vancomycin, daptomycin, linezolid, tigecycline, ceftaroline, doxycycline.
resistant bacteria VRE: linezolid, tigecycline, and streptogramins (quinupristin, dalfopristin).
Multidrug-resistant P aeruginosa, multidrug-resistant Acinetobacter baumannii: polymyxins B and
E (colistin).

Antifungal therapy

FUNGAL CELL
LANOSTEROL SYNTHESIS CELL WALL SYNTHESIS

Terbinafine – Cell wall Echinocandins
Squalene – Anidulafungin
Caspofungin
Squalene epoxidase Micafungin
Squalene epoxide
CELL MEMBRANE INTEGRITY
Nucleus
ERGOSTEROL SYNTHESIS Lanosterol Polyenes
Amphotericin B
14–α–demethylase Nystatin
Azoles Ergosterol
Clotrimazole
Fluconazole Ergosterol
Itraconazole NUCLEIC ACID SYNTHESIS
Ketoconazole – Cell membrane
Miconazole –
Voriconazole Flucytosine

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