title: In Vitro Antimicrobial Susceptibility of Nontuberculous Mycobacteria in Iran.
abstract: Many species of nontuberculous mycobacteria (NTM) have long been identified as important causes of human disease, the incidence of which is rising. Several reports have suggested increasing trend of both in vitro and in vivo resistance to available treatment regimes. The aim of this study was to evaluate antibiotic susceptibility of clinically relevant NTM isolates using standard microbroth dilution test. Antimicrobial susceptibility testing was performed following National Committee for Clinical Laboratory Standards methods for NTM isolates, including 85 Mycobacterium fortuitum, 39 Mycobacterium chelonae, and 30 Mycobacterium abscessus subsp. abscessus as rapidly growing mycobacteria and 48 Mycobacterium simiae and 40 Mycobacterium kansasii as slowly growing mycobacteria. All isolates were recovered from various types of clinical samples and identified by multilocus sequence analysis. Trimethoprim-sulfamethoxazole (TMP-SMZ), amikacin, tobramycin, clarithromycin, moxifloxacin, linezolid, and imipenem showed better activity against M. fortuitum rather than meropenem, ciprofloxacin, cefoxitin, and doxycycline. Amikacin was active against 93% of M. abscessus subsp. abscessus. Linezolid, clarithromycin, cefoxitin, ciprofloxacin, imipenem, moxifloxacin, tobramycin, TMP-SMZ, doxycycline, and meropenem showed some activities on M. abscessus subsp. abscessus as well. The majority of M. abscessus subsp. abscessus and M. chelonae strains were multidrug resistant. Among the 40 isolates of M. kansasii, all were susceptible to ethambutol, isoniazid, clarithromycin, moxifloxacin, and linezolid. These isolates were also resistant to doxycycline and 50% were resistant to rifampicin and ciprofloxacin. M. simiae was resistant to clarithromycin, doxycycline, isoniazid, and TMP-SMZ, and the majority of isolates showed high levels of resistance to linezolid, ethambutol, ciprofloxacin, streptomycin, and rifampicin. The majority of M. simiae isolates were multidrug resistant. Our data confirm the need for performing of standard susceptibility testing of any clinically important NTM isolate.
authors.affiliation: 1 Department of Microbiology, School of Medicine, Alborz University of Medical Sciences , Alborz, Iran .
authors.forename: Parvin
authors.initials: P
authors.lastname: Heidarieh
authors.affiliation: 2 Division of Pulmonary and Critical Care, Miller School of Medicine, University of Miami, Miami , Florida.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mirsaeidi
authors.affiliation: 3 Health Research Institute, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences , Ahvaz, Iran .
authors.forename: Mohamad
authors.initials: M
authors.lastname: Hashemzadeh
authors.affiliation: 4 Department of Microbiology, School of Medicine, Tehran University of Medical Sciences , Tehran, Iran .
authors.forename: Mohamad Mehdi
authors.initials: MM
authors.lastname: Feizabadi
authors.affiliation: 5 Biology and Microbiology Department, Islamic Azad University Parand Branch , Tehran, Iran .
authors.forename: Saeed Zaker
authors.initials: SZ
authors.lastname: Bostanabad
authors.affiliation: 6 Reference Health Laboratory of Iran (RHL) , Tehran, Iran .
authors.forename: Mostafa Ghalami
authors.initials: MG
authors.lastname: Nobar
authors.affiliation: 7 Department of Epidemiology, Pasteur Institute of Iran , Tehran, Iran .
authors.forename: Abodolrazagh
authors.initials: A
authors.lastname: Hashemi Shahraki
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004977:Ethambutol / Q000494:pharmacology; D006801:Humans; D007492:Iran; D000069349:Linezolid / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009165:Mycobacterium Infections, Nontuberculous / Q000382:microbiology; D009170:Nontuberculous Mycobacteria / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D015363:Quinolones / Q000494:pharmacology; D013754:Tetracyclines / Q000494:pharmacology
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D015780:Carbapenems; D015363:Quinolones; D013754:Tetracyclines; D004977:Ethambutol; D000069349:Linezolid