An international serotype 3 clone causing pediatric noninvasive infections in Israel, Costa Rica, and Lithuania.
BACKGROUND
Serotype 3 is known for its ability to cause invasive diseases worldwide. In the United States, after introduction of the 7-valent pneumococcal conjugate vaccine (PCV7), the prevalence of a serotype 3 clone (Netherlands-31/ST180) increased. The present study was aimed to evaluate the importance of serotype 3 clones in noninvasive infections in Israel, Costa Rica, and Lithuania.


METHODS
Molecular typing and antibiotic resistance were performed on 77 serotype 3 strains recovered from pediatric noninvasive infections during 2003-2005, and on 50 carried strains from healthy carriers.


RESULTS
Serotype 3 ranked second among isolates from noninvasive infections in Costa Rica and Lithuania, and seventh among the Israeli isolates. Pulsed field gel electrophoresis (PFGE) analysis revealed the presence of 1 major cluster (64/77, 83%); this cluster comprised 60/64 fully susceptible strains that corresponded to the Netherlands-31/ST180 clone, and 4/64 multidrug-resistant strains, all from Lithuania, that corresponded to ST505, a double locus variant of ST180. Two additional fully susceptible clones, ST458 (11/77, 14%) and ST1116 (2/77, 3%), were found among the Israeli and Costa Rican strains, respectively. The same PFGE clusters identified among noninvasive infections were found among 50 isolates from carriers, with the same molecular characteristics.


CONCLUSIONS
Serotype 3 accounts for a large proportion of mucosal disease in children, even before the introduction of PCV7. The data presented here describe for the first time the importance of a multidrug-resistant serotype 3 clone, ST505, in noninvasive infections.
Porat
Nurith
N
Pediatric Infectious Disease Unit, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. npurat@bgumail.bgu.ac.il
Soley
Carolina
C
Marengolciene
Marija M
MM
Greenberg
David
D
Givon-Lavi
Noga
N
Trefler
Ronit
R
Arguedas
Adriano
A
Dagan
Ron
R
D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D003364:Costa Rica / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007557:Israel / Q000453:epidemiology; D008097:Lithuania / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins