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Epidemiological analysis of pneumococcal carriage in Hungarian children from a day-care centre

Abstract number: P939

Dobay O., Tóthpál A., Kardos S., Hajdú E., Nagy E., Amyes S., Nagy K.

Objectives: The carriage of Streptococcus pneumoniae (pneumococci) plays a major role in the transmission of bacteria to sensitive individuals. The carriage rate can reach 50–100% in small children, especially attending day-care centres. Prevenar was proven also to have an effect on the carriage. As this vaccine became widely available in Hungary for children <2 y in Oct 2008, it was important to examine the carriage of pneumococcal strains before the vaccination programme was implemented.

Methods: Thirty-four pneumococcal isolates were collected from the nasal passages of children attending a day-care centre in Szeged, Hungary. The species identity of all strains was confirmed by the presence of the lytA gene. Their antibiotic sensitivity was determined by E-test, applying the EUCAST breakpoints. Serotyping was done by the combination of the conventional method (with antisera) and a PCR-based method. The genetic relatedness of the strains was examined by PFGE.

Results: We could serotype 25 out of the 34 strains (=73.5%). The detected serotypes were (n): 14 (6), 6A (6), 3 (3), 13 (2), 18C (2), 9L, N (2), 9V (1), 19A (1), 19F (1), 15A (1). None of the strains were resistant (R) to penicillin (pen), the highest MICs (0.5–0.75 mg/L) were detected in sero 14 isolates. Serotypes 6A and 19 also fell in the pen I category. All isolates were sensitive (S) to levofloxacin. Seven strains showed high-level R to erythromycin (ery), these were of different serotypes, and 4 carried the erm(B) gene. Five strains were R to ery (6–24 mg/L), but S to clindamycin (M type), all these were of sero 14, identical by PFGE and had the mef gene. One single sero 14 strain was S to everything, and shared PFGE identity with one sero 13 strains. The six sero 6A strains formed 2 PFGE clones, mirroring the different pen and ery MICs.

Conclusions: It is surprising to observe the absence of the usually frequent serotype 23F among the carried strains, and the presence of the rather rare serotype 13. Based on our data, and taking certain cross-protections into account, Prevenar (serotypes 4, 6B, 9V, 14, 18C, 19F, 23F) would cover 18 out of the 25 isolates (72.0%), or 52.9%, if we relate it to all 34 strains. The presence of a mef+ serotype 14 clone (very probably the England 14–9 PMEN clone) was observed. An interesting serotype switch was detected between sero 14 and 13. This study involves only a small number of isolates; however, this is the first study on pneumococcal carriage in Hungary.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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