Optochin resistance in Streptococcus pneumoniae: mechanism, significance, and clinical implications - PubMed (original) (raw)

. 2001 Sep 1;184(5):582-90.

doi: 10.1086/322803. Epub 2001 Jul 26.

Affiliations

Optochin resistance in Streptococcus pneumoniae: mechanism, significance, and clinical implications

A Pikis et al. J Infect Dis. 2001.

Abstract

Traditionally, Streptococcus pneumoniae is identified in the laboratory by demonstrating susceptibility to optochin. Between 1992 and 1998, 4 pneumococcal isolates exhibiting optochin resistance were recovered from patients at Children's National Medical Center. Three of the 4 isolates consisted of mixed populations of optochin-resistant and -susceptible organisms. Both subpopulations had identical antibiograms, serotypes, and restriction fragment profiles. The other isolate was uniformly resistant to optochin. Resistant strains had MICs of optochin 4-30-fold higher than susceptible strains, belonged to different serotypes, and had dissimilar restriction fragment profiles, indicating clonal unrelatedness. Resistance arose from single point mutations in either the a-subunit (W206S) or the c-subunit (G20S, M23I, and A49T) of H(+)-ATPase. There is speculation of a possible association between exposure to antimalarial drugs and evolution of optochin resistance. alpha-Hemolytic streptococci resistant to optochin, particularly invasive isolates, should be tested for bile solubility or with an S. pneumoniae DNA probe before identification as viridans streptococci.

PubMed Disclaimer

Similar articles

Cited by

MeSH terms

Substances

LinkOut - more resources