Prevalence of macrolide resistance and in vitro activities of six antimicrobial agents against clinical isolates of Streptococcus pneumoniae from a multi-center surveillance in Malaysia
- Author:
Jayakayatri Jeevajothi Nathan
;
Niazlin Mohd Taib
;
Mohd Nasir Mohd Desa
;
Siti Norbaya Masri
;
Rohani Md Yasin
;
Farida Jamal
;
Sreenivasa Rao Sagineedu
;
Arunkumar Karunanidhi
- Publication Type:Journal Article
- From:
The Medical Journal of Malaysia
2013;68(2):119-124
- CountryMalaysia
- Language:English
-
Abstract:
The in vitro activities of 6 antimicrobial agents against
clinical isolates of Streptococcus pneumoniae
(pneumococci) were investigated and the erythromycin
minimum inhibitory concentrations (MICs) were correlated
with the two major macrolide resistance determinants,
mef(A) and erm(B). MICs of commonly used antibiotics as
well as the presence of macrolide resistance determinant
genes in all isolates were tested. Seventy one
pneumococcal isolates collected at Institute for Medical
Research (IMR) were included in this study. Phenotypic
characterization, MIC determination using E-test strips and
polymerase chain reactions for antibiotic resistance
determination were included. Among the isolates, 25 (35.2%)
isolates were erythromycin susceptible, 3 (4.2%) were
intermediate and 42 (60.6%) were resistant. Fifty three
isolates (74.7%) were found with mef(A) alone, 15 (21.1%)
isolates with erm(B) + mef(A) combination and 3 (4.2%)
isolates with none of the two genes. The in vitro activity of penicillin, amoxicillin clavulanic acid, ceftriaxone and
cefotaxime is superior to trimethoprim-sulfamethoxazole
and erythromycin. In conclusion, pneumococcal isolates in
this study were highly susceptible to penicillin with very low MICs. However, a very high prevalence rate of erythromycin resistance was observed. Erythromycin resistant S.pneumoniae isolates with both mef(A) and erm(B) showed very high MICs ≥256 μg/mL.
