Determination of penicillin resistance in Streptococcus pneumoniae isolates from southern Brazil by PCR.
OBJECTIVE
To demonstrate the potential clinical applicability of the PCR technique to the early detection of bacterial resistance in Streptococcus pneumoniae.


METHODS
We studied 153 samples of S. pneumoniae, isolated from different anatomic sites, using polymerase chain reaction (PCR) for the detection of specific amplicons from genes that code for penicillin-binding proteins (PBP) 1a, 2b and 2x, which are responsible for penicillin resistance in this organism. The occurrence of these mutated genes was correlated with the minimum inhibitory concentration (MIC) of penicillin, determined by the agar dilution test.


RESULTS
The rate of penicillin resistance in S. pneumoniae in Porto Alegre, Brazil was 22.8% (16.3% intermediate resistance and 6.5% high resistance). In a statistically significant proportion of cases (p < 0.05), penicillin-susceptible samples had no amplicons, intermediate samples had only one (generally from PBP 2x), and highly resistant samples had amplicons from all three PBPs investigated.


CONCLUSIONS
These results suggest that penicillin resistance in S. pneumoniae in southern Brazil is on the increase, but is still lower than in other countries, and that PCR could be used for its early detection.
Zettler
Eduardo Walker
EW
Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Avenida Ipiranga, 6690 - conjunto 501, Bairro Jardim Botânico, Porto Alegre - RS, CEP: 90660-000, Brazil. ewzettler@terra.com.br
Scheibe
Rosane Machado
RM
Dias
Cícero A G
CA
Santafé
Patrícia
P
Santos
Diógenes Santiago
DS
Moreira
José da Silva
Jda S
Fritscher
Carlos Cezar
CC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D015169:Colony Count, Microbial; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D010403:Penicillin Resistance / Q000235:genetics; D046915:Penicillin-Binding Proteins / Q000235:genetics*; D011008:Pneumococcal Infections / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D046915:Penicillin-Binding Proteins