[Assessment of in vitro susceptibility to antimicrobials of rapidly growing mycobacteria by E-test].
BACKGROUND
Rapidly growing mycobacteria (RGM) are considered opportunistic pathogens. An increasing number of post traumatic or surgical infections are caused by these microorganisms.


OBJECTIVE
To determine the antimicrobial susceptibility of RGM using the E-test method.


METHODS
A total of 54 isolates of RGM was obtained from several clinical samples and selected for this study Strains were identified to the species level by phenotypic and biochemical characteristics, PCR-restriction enzyme analysis of the hsp65 gene (PRA) and sequencing of the 16S rRNA. Susceptibility was investigated by E-test to amikacin, cefoxitin, ciprofioxacin, clarithromycin, imipenem, quinupristin/dalfopristin, linezolid and tigecycline.


RESULTS
Twelve different species of RGM were identified: Mycobacterium fortuitum (23 strains), M chelonae (11), M abscessus (10), Msenegalense (2), Malvei (1), Mbrumae (1), Mmageritense (1), mucogenicum (1), M neoaurum (1), Mperegrinum (1), M septicum (1) y M smegmatis (1). All the strains were inhibited by low concentrations of amikacin and tigecycline. Susceptibility to cefoxitin, fluoroquinolones, clarithromycin, imipenem and linezolid was variable. All but two strains were resistant to quinupristin/ dalfopristin.


CONCLUSIONS
Due to the uneven antimicrobial susceptibility of different species of RGM, an antimicrobial susceptibility test is mandatory for these microorganisms. The E-test method is well suited to determine minimum inhibitory concentrations.
García-Agudo
Lidia
L
Hospital Universitario de Puerto Real, Cádiz, España. lidiagarciaagudo@gmail.com
García-Martos
Pedro
P
Jesús
Iría
I
Rodríguez-Iglesias
Manuel
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000145:classification / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods*; D008875:Middle Aged; D009161:Mycobacterium / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D055815:Young Adult
D000900:Anti-Bacterial Agents