We need you! Join our contributor community and become a WikEM editor through our open and transparent promotion process.
Viridans-Group Streptococci
From WikEM
Contents
Background
- A Gram Positive Bacteria in the Streptococcus Genus
- In general, low virulence pathogens and likely Blood Culture Contaminant unless risk factor (21-50% of positive blood cultures are clinically significant)[1]
Types
- Streptococcus milleri
- Streptococcus sanguis
- Streptococcus mitis
- Streptococcus bovis
Risk Factors for Viridans Bacteremia[2]
- neutropenia
- oral mucositis
- irradiation to the oral cavity
- antibiotic prophylaxis with trimethoprim-sulfamethoxazole or fluoroquinolones
- intravenous hyperalimentation
- high dose chemotherapy
Antibiotic Sensitivities[3]
| Category | Antibiotic | Viridans strep |
| Penicillins | Penicillin G | I |
| Penicillin V | I | |
| Methicillin | I | |
| Nafcillin/Oxacillin | I | |
| Cloxacillin/Diclox. | I | |
| Amino-Penicillins | AMP/Amox | I |
| Amox-Clav | I | |
| AMP-Sulb | I | |
| Anti-Pseudomonal Penicillins | Ticarcillin | I |
| Ticar-Clav | I | |
| Pip-Tazo | I | |
| Piperacillin | I | |
| Carbapenems | Doripenem | S |
| Ertapenem | S | |
| Imipenem | S | |
| Meropenem | S | |
| Aztreonam | R | |
| Fluroquinolones | Ciprofloxacin | R |
| Ofloxacin | R | |
| Pefloxacin | X1 | |
| Levofloxacin | S | |
| Moxifloxacin | S | |
| Gemifloxacin | S | |
| Gatifloxacin | S | |
| 1st G Cephalo | Cefazolin | S |
| 2nd G. Cephalo | Cefotetan | S |
| Cefoxitin | S | |
| Cefuroxime | S | |
| 3rd/4th G. Cephalo | Cefotaxime | S |
| Cefizoxime | S | |
| CefTRIAXone | S | |
| Ceftaroline | S | |
| CefTAZidime | I | |
| Cefepime | S | |
| Oral 1st G. Cephalo | Cefadroxil | S |
| Cephalexin | S | |
| Oral 2nd G. Cephalo | Cefaclor/Loracarbef | S |
| Cefproxil | R | |
| Cefuroxime axetil | S | |
| Oral 3rd G. Cephalo | Cefixime | S |
| Ceftibuten | R | |
| Cefpodox/Cefdinir/Cefditoren | S | |
| Aminoglycosides | Gentamicin | X1 |
| Tobramycin | X1 | |
| Amikacin | X1 | |
| Chloramphenicol | X1 | |
| Clindamycin | X1 | |
| Macrolides | Erythromycin | X1 |
| Azithromycin | X1 | |
| Clarithromycin | X1 | |
| Ketolide | Telithromycin | X1 |
| Tetracyclines | Doxycycline | X1 |
| Minocycline | X1 | |
| Glycylcycline | Tigecycline | X1 |
| Daptomycin | X1 | |
| Glyco/Lipoclycopeptides | Vancomycin | X1 |
| Teicoplanin | X1 | |
| Telavancin | X1 | |
| Fusidic Acid | X1 | |
| Trimethoprim | X1 | |
| TMP-SMX | X1 | |
| Urinary Agents | Nitrofurantoin | X1 |
| Fosfomycin | X1 | |
| Other | Rifampin | X1 |
| Metronidazole | X1 | |
| Quinupristin dalfoppristin | X1 | |
| Linezolid | X1 | |
| Colistimethate | X1 |
Key
- S susceptible/sensitive (usually)
- I intermediate (variably susceptible/resistant)
- R resistant (or not effective clinically)
- S+ synergistic with cell wall antibiotics
- U sensitive for UTI only (non systemic infection)
- X1 no data
- X2 active in vitro, but not used clinically
- X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
- X4 active in vitro, but not clinically effective for strep pneumonia
Table Overview
| ||||||||||||||||||||||||||||||||||||||||
See Also
References
- ↑ Antibiotic Therapy for Positive Blood Cultures. Perez-Jorge EV, et al. Antimicrobe. http://www.antimicrobe.org/new/e38rev2.asp
- ↑ Antibiotic Therapy for Positive Blood Cultures. Perez-Jorge EV, et al. Antimicrobe. http://www.antimicrobe.org/new/e38rev2.asp
- ↑ Sanford Guide to Antimicrobial Therapy 2014
