Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2004 Sep;65(5):423-32.
doi: 10.1016/j.curtheres.2004.10.005.

Phenotypic and genotypic characterization of invasive Streptococcus pneumoniae clinical isolates

Abdulaziz M Al-Swailem  1 , Ashraf A Kadry  2 , Soliman I Fouda  2 , Atef M Shibl  2 , Omar H Shair  1
Affiliations

Phenotypic and genotypic characterization of invasive Streptococcus pneumoniae clinical isolates

Abdulaziz M Al-Swailem et al. Curr Ther Res Clin Exp. 2004 Sep.

Abstract

Background: The emergence of infection caused by invasive penicillinnonsusceptible (PNS) and multidrug-resistant strains of Streptococcus pneumoniae has become a worldwide concern, necessitating the epidemiologic surveillance of such strains.

Objectives: One aim of this study was to identify clones of invasive PNS S pneumoniae among isolates in Riyadh, Saudi Arabia. The second aim was to compare these clones with international clones to track their spread in Saudi Arabia.

Methods: The phenotypes of invasive isolates characterized as S pneumoniae were determined using susceptibility testing and serotyping (capsular test and E-test). The genotypes of PNS isolates were determined using random amplified polymorphic DNA analysis. The genetic relatedness of these local strains to the international widespread clones was investigated.

Results: Of 296 S pneumoniae isolates identified using biochemical and culture characteristics, 89 (30.1%) were invasive. Susceptibility testing using the E-test revealed that 17 of the 89 invasive isolates (19.1%) were PNS. Most of the 89 isolates (89.9%) were resistant to sulfamethoxazole-trimethoprim; 32.6% and 23.6% of isolates were resistant to chloramphenicol and tetracycline, respectively. All of the isolates (100.0%) were fully susceptible to ceftriaxone and vancomycin. Capsular serotyping of the 89 isolates showed that 19A (18.0%), 613 (14.6%), 23F (13.5%), 9V (11.2%), 14 (6.7%), 19F (5.6%), and 18C (4.5%) were the most predominant serogroups/serotypes. The 17 PNS strains were confirmed on polymerase chain reaction to have penicillin resistance genes. Of these 17 strains, international clone 19A-a was the most predominant (41.2%), followed by 6B-a (17.6%), and 23F-a and 9V-a (each, 11.8%).

Conclusions: The present study identified the spread of the 4 most commonPNS S pneumoniae isolates (clones)-19A, 613, 23F, and 9V-to Riyadh, but identified no new clones among patients having invasive infection with S pneumoniae in Riyadh. This study emphasizes that international PNS clones have contributed to the prevalence and spread of PNS pneumococci among the clinical isolates in Saudi Arabia.

Keywords: Streptococcus pneumoniae; randomamplified polymorphic DNA analysis; serotyping; susceptibility.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. Bogaert D., Syrogiannopoulos G.A., Grivea I.N. Molecular epidemiology of penicillin-nonsusceptible Streptococcus paeumoaiae among children in Greece. J Clin Microbiol. 2000;38:4361–4366. - PMC - PubMed
    1. Rudolph K.M., Parkinson A.J., Roberts M.C. Molecular analysis by pulsed-field gel electrophoresis and antibiogram of Streptococcus paeumoaiae serotype 6B isolates from selected areaswithin the United States. J Clin Microbiol. 1998;36:2703–2707. - PMC - PubMed
    1. Twum-Danso K., Al-Mazrou A.M., Kambal A.M., Al-Zamil F.A. Penicillin resistance in serogroups/serotypes of Streptococcus paeumoaiae causing invasive infections in Central Saudi Arabia. Saudi Med J. 2003;24:1210–1213. - PubMed
    1. Dunne W.M., Jr, K.S. Kehl, Holland-Staley C.A. Comparison of results generated by serotyping, pulsed-field restriction analysis, ribotyping, and repetitive-sequence PCR used to characterize penicillin-resistant pneumococci from the United States. J Clin Microbiol. 2001;39:1791–1795. - PMC - PubMed
    1. Overweg K., Hermans P.W., Trzcinski K. Multidrug-resistant Streptococcus pneumoniae in Poland: Identification of emerging clones. J Clin Microbiol. 1999;37:17391745. - PMC - PubMed

LinkOut - more resources