Antimicrobial susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis collected from five centers in Brazil, 1997-98.
OBJECTIVE
To assess the susceptibility of the key respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to antimicrobial agents used to treat respiratory tract infections.


METHODS
Isolates were collected from five centers in Brazil during 1997-98, and susceptibility testing was conducted at a central laboratory according to National Committee for Clinical Laboratory Standards criteria.


RESULTS
Of the 359Streptococcus pneumoniae isolates tested, 77% were susceptible, 19% were intermediate and 4% were resistant to penicillin. The susceptibility of S. pneumoniae to other beta-lactams and macrolides was greater than 90%, but cotrimoxazole was active against only 48% of the isolates. The prevalence of susceptible isolates was 100.0% for vancomycin and 99.7% for levofloxacin. beta-Lactam, macrolide, and cotrimoxazole activities were negatively associated with penicillin resistance. Of the 219 isolates of Haemophilus influenzae tested, 11% produced beta-lactamase and 11% were not susceptible to ampicillin. Nearly all H. influenzae isolates were susceptible to all other drugs, except cotrimoxazole (47% susceptibility). Of the 52 Moraxella catarrhalis isolates, 98% produced beta-lactamase, and the MIC of all drugs was </=4 mg/L, with the exception of ampicillin, where the MIC90 was> 8 mg/L.


CONCLUSIONS
When these data are compared with previous reports, our findings suggest that the prevalence of pneumococci that are resistant to agents such as penicillin and cotrimoxazole may be increasing in Brazil, which highlights the need to continue surveillance programs.
Critchley
I A
IA
MRL Pharmaceutical Services, Herndon, VA, USA. icritchley@thetsn.com
Thornsberry
C
C
Piazza
G
G
Jones
M
M
Hickey
M L
ML
Barth
A L
AL
Mendes
C
C
Rossi
F F
FF
Sader
H S
HS
Teixeira
L M
LM
Sahm
D F
DF
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001938:Brazil; D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects*; D010403:Penicillin Resistance; D012141:Respiratory Tract Infections / Q000188:drug therapy* / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects*
D000900:Anti-Bacterial Agents