Characterization of macrolide resistance in Gram-positive cocci from Colombian hospitals: a countrywide surveillance.
OBJECTIVE
The characterization of macrolide resistance in Gram-positive cocci recovered from Colombian hospitals.


METHODS
The resistance profiles and mechanism of macrolide resistance were investigated in isolates of Streptococcus pneumoniae (1679), Staphylococcus aureus (348), coagulase-negative staphylococci (CoNS) (175), and Enterococcus spp (123). Minimum inhibitory concentrations (MICs) for erythromycin (ERY) and clindamycin (CLI), detection of macrolide resistance genes, phenotypic characterization, and pulsed field gel electrophoresis (PFGE) of macrolide-resistant pneumococci were performed.


RESULTS
Resistance to ERY and CLI was 3.3% and 2.3% for S. pneumoniae, 58% and 57% for S. aureus (94% for both compounds in methicillin-resistant Staphylococcus aureus (MRSA)), and 78.6% and 60.7% in methicillin-resistant Staphylococcus epidermidis, respectively. ERY resistance was 62% in Enterococcus faecalis and 82% in Enterococcus faecium. The MLS(B)-type accounted for 71% of S. pneumoniae and 100% of MRSA. The erm(A) gene was prevalent in MRSA, erm(B) in S. pneumoniae and enterococci, and erm(C) in CoNS isolates. Efflux pump genes (mef(A) genes) were mostly identified in S. pneumoniae (24%). The most common genotype amongst ERY-resistant pneumococci was the Spain(6B)-2 clone.


CONCLUSIONS
The prevalence of macrolide resistance is low in Colombian pneumococci and high in MRSA (cMLS(B)-type).
Reyes
Jinnethe
J
Bacterial Molecular Genetics Unit, Centro de Investigaciones, Universidad El Bosque, Bogotá, Colombia.
Hidalgo
Marylin
M
Díaz
Lorena
L
Rincón
Sandra
S
Moreno
Jaime
J
Vanegas
Natasha
N
Castañeda
Elizabeth
E
Arias
César A
CA
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003105:Colombia / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D006095:Gram-Positive Cocci / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010641:Phenotype
D000900:Anti-Bacterial Agents; D018942:Macrolides