Streptococcus pneumoniae in children in Spain: 1990-1999.

UNLABELLED: This study analyses the serogroups/types (SGTs) and resistance to penicillin and erythromycin of 3921 strains isolated from 1990 to 1999 in children aged 0-14 y in Spanish hospitals of all the autonomous communities. Based on the age of the children, strains have been divided into five groups: 0-6 mo, > 6-1 y, > 1-2 y, > 2-5 y and > 5 y. While only eight SGTs were responsible for 80% of the infections in children from 6 mo to 2 y of age, this number increased to 11 and 16 for the groups > 2-5 y and > 5-14 y, respectively. SGTs 6, 14 and 19 were prevalent in blood and otic exudates. SGTs 1, 4, 5, 12 and 18 were more frequent in invasive disease but serotype 3 was clearly associated with otitis. Serotypes I and 5 were quite significant in children of over 2 y of age, and this should be taken into account in future vaccine formulations. CONCLUSION: Although high, the rate of penicillin resistance in the paediatric population has remained stable in recent years. Conversely, erythromycin resistance is still increasing in our country. Coverage by the 7-valent vaccine was 78 and 81% for blood and otic isolates, respectively. These coverage levels would be increased by 9% and 3% if 9-valent (plus 1 + 5 serotypes) were used and by an additional 2.6% and 7.6% using the 11-valent (plus 3 + 7) formulation.

Dot blot assay for the serotyping of pneumococci.

To simplify the serotyping of Streptococcus pneumoniae, a dot bot assay has been developed and compared with the standard quellung reaction in 1,082 isolates. The technique has been demonstrated to be sensitive, specific, easy to perform, and inexpensive. The dot blot assay could be useful when large numbers of pneumococci have to be studied.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates causing systemic infections in Spain, 1979-1989.

Serotypes and antibiotic susceptibilities were determined for 2,197 Streptococcus pneumoniae strains isolated from patients with systemic infections over an 11-year period. The predominant serogroups and serotypes, in order of decreasing frequency, were 3, 6, 23, 19, 9, 1, 5, 8, 7, 14, 4, and 15; these types accounted for more than 75% of the strains studied. Altogether, 93% of the pneumococci belonged to groups or types included in the 23-valent pneumococcal vaccine. Overall, 65.5% of pneumococci were resistant to one or more drugs. The incidence of penicillin-resistant pneumococci rose from 6% in 1979 to 44% in 1989, and the degree of penicillin resistance also increased throughout the study. Overall, the resistance rates were 28% for penicillin, 56% for tetracycline, 43% for chloramphenicol, and 5% for erythromycin. Seventy-one pneumococcal isolates resistant to all four antibiotics tested were found. The prevalence of pneumococcal resistance in Spain is, as far as we know, among the highest published to date.

Optochin-resistant variants of Streptococcus pneumoniae.

Ten Streptococcus pneumoniae clinical isolates, possessing physiologically typical pneumococcal characteristics, showed optochin-susceptible and optochin-resistant colonies around the optochin disk, when tested for optochin susceptibility. Equivocal optochin disk test results should be confirmed by bile solubility, agglutination tests, or both.