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Antimicrobial susceptibility of viridans group streptococci

M Tuohy1, J A Washington

  • 1Cleveland Clinic Foundation, Ohio 44195-5140, USA.

Diagnostic Microbiology and Infectious Disease
|February 12, 1998
PubMed

Insights

Viridans group streptococci exhibit varying susceptibility to common antibiotics. Levofloxacin, quinupristin/dalfopristin, and rifampin demonstrated high activity against all tested strains, including Streptococcus sanguis, mitis, salivarius, and milleri.

Area of Science:

  • Clinical Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Viridans group streptococci are common causes of various infections.
  • Understanding antibiotic susceptibility patterns is crucial for effective treatment.
  • Resistance to traditional antibiotics is an increasing concern in clinical settings.

Purpose of the Study:

  • To determine the in vitro antibiotic susceptibility of clinical isolates of viridans group streptococci.
  • To evaluate the efficacy of a broad range of antibiotics against Streptococcus sanguis, Streptococcus mitis, Streptococcus salivarius, and Streptococcus milleri.

Main Methods:

  • A total of 68 viridans group streptococci isolates were tested.
  • Antibiotic susceptibility was assessed using the microdilution method.
  • Isolates included Streptococcus sanguis, Streptococcus mitis, Streptococcus salivarius, and Streptococcus milleri from blood and sterile sites.

Main Results:

  • High susceptibility rates (≥94%) were observed for Streptococcus sanguis against ceftriaxone, clindamycin, and vancomycin.
  • Streptococcus mitis showed variable susceptibility, with 100% susceptibility to clindamycin and vancomycin.
  • Streptococcus milleri isolates were 100% susceptible to penicillin, amoxicillin, ceftriaxone, clindamycin, and vancomycin.
  • Levofloxacin, quinupristin/dalfopristin, and rifampin demonstrated high activity against all tested viridans group streptococci.

Conclusions:

  • Antibiotic susceptibility varies significantly among different species of viridans group streptococci.
  • Vancomycin and clindamycin are highly effective against most tested strains.
  • Levofloxacin, quinupristin/dalfopristin, and rifampin represent promising therapeutic options for infections caused by these bacteria.

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