Jf. Sessegolo et al., DISTRIBUTION OF SEROTYPES AND ANTIMICROBIAL RESISTANCE OF STREPTOCOCCUS-PNEUMONIAE STRAINS ISOLATED IN BRAZIL FROM 1988 TO 1992, Journal of clinical microbiology, 32(4), 1994, pp. 906-911
Forty-two serotypes were identified among 288 Streptococcus pneumoniae
strains isolated from patients living in Brazil. Serotyping was deter
mined by the capsular typing test (Quellung reaction). Types 14 (10.4%
), 6B (9.8%), 23F (8.0%), 5 (7.3%), 19F (6.9%), 6A (6.0%), and 1 and 4
(4.6%) were the most commonly identified strains. Two hundred twenty
(76.4%) of the strains were of serotypes that are included in the 23-v
alent pneumococcal polysaccharide vaccine. If vaccine-related serotype
s are also considered, the proportions of coverage in the vaccine are
82.3% (if type 6B alone is added) and 85.7% (if all the vaccine-relate
d types are considered to be cross-protecting). Decreased susceptibili
ty to penicillin, which was identified by using the 1-mug oxacillin di
sk method as a screening test, was detected in 70 (26.7%) strains. The
MICs of nine antimicrobial agents were determined by using the proced
ures recommended by the National Committee for Clinical Laboratory Sta
ndards. Seventy (35.9%) of the strains were resistant to tetracycline,
57 (29.2%) were resistant to sulfamethoxazole-trimethoprim, 3 (1.5%)
were resistant to rifampin, 2 (0.80%) were resistant to penicillin, an
d 1 (0.5%) was resistant to chloramphenicol. The two penicillin-resist
ant strains were also resistant to or had decreased susceptibilities t
o cephalosporins. Forty-seven (17.9%) of the strains were intermediate
ly resistant to penicillin, 17 (8.7%) were intermediately resistant to
tetracycline, 13 (6.7%) were intermediately resistant to chlorampheni
col, 12 (6.1%) were intermediately resistant to erythromycin, and 6 (3
.1%) were intermediately resistant to rifampin.