[Staphylococcus aureus prevalence among preschool- and school-aged pupils].
OBJECTIVE
To determine the prevalence and incidence of Staphylococcus aureus strains among preschool- and school-aged pupils and susceptibility of these strains to antimicrobial materials.


METHODS
A study of 243 preschool- and 300 school-aged pupils was conducted during 2003-2004. Identification of Staphylococcus aureus was made with plasmacoagulase and DNase tests. The resistance of Staphylococcus aureus to antibiotics, beta-lactamase activity, phagotypes, and phage groups were determined. The isolated Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 microg per disk and oxacillin 1 microg per disk).


RESULTS
A total of 292 (53.8%) Staphylococcus aureus strains were isolated and identified (113 (46.5%) from preschool- and 179 (59.7%) from school-aged pupils). The prevalence of Staphylococcus aureus strains among preschool-aged pupils varied from 46.5% to 47%. It increased to 59.0% (P>0.05) among schoolchildren aged from 11 to 15 years and to 73.0% (P<0.001) among schoolchildren aged from 16 to 19 years. Six methicillin-resistant Staphylococcus aureus strains were isolated: two (1.8%) of them were from preschool-aged and four (2.2%) from school-aged pupils. The prevalence of Staphylococcus aureus strains with beta-lactamase activity increased from 70.7 to 76.6% in preschool-aged pupils, and it varied from 72.0 to 79.0% in school-aged pupils (P>0.05). Staphylococcus aureus strains of phage group II (32.2-43.4%) were prevailing; nontypable Staphylococcus aureus strains made up 19.2-33.6%.


CONCLUSIONS
The prevalence of Staphylococcus aureus among preschool-aged children is 41.7 to 48.8%, and it increases among 9th-12th-grade pupils (73.0%, P<0.001). Some Staphylococcus aureus strains (2.1%) were resistant to methicillin. Staphylococcus aureus strains of phage group II (39.0%, P<0.05) are most prevalent among preschool- and school-aged pupils. Pupils were colonized with methicillin-resistant Staphylococcus aureus strains belonging to phage group III phagotype 83A and 77.
Pavilonyte
Zaneta
Z
Department of Microbiology, Kaunas University of Medicine, Kaunas, Lithuania. mikrobas@kmu.lt
Kacerauskiene
Justina
J
Budryte
Brigita
B
Keizeris
Tadas
T
Junevicius
Jonas
J
Pavilonis
Alvydas
A
D000293:Adolescent; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques; D001434:Bacteriophage Typing; D002353:Carrier State / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D003470:Culture Media; D003627:Data Interpretation, Statistical; D006801:Humans; D008712:Methicillin / Q000494:pharmacology*; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000382:microbiology; D009296:Nasal Cavity / Q000382:microbiology; D013204:Staphylococcus Phages; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D003470:Culture Media; D008712:Methicillin