Aim: Data are limited regarding the antibiotic susceptibility of Legionella pneumophila in India. The aim of this study was to determine the drug susceptibility of environmental L. pneumophila isolates in India for antibiotics commonly used in clinical practice for Legionnaires' disease treatment. Materials & methods: The activities of seven antibiotics against 46 environmental isolates of L. pneumophila were evaluated by using E-test on buffered charcoal yeast extract-α agar. Results: Among the L. pneumophila isolates tested, no tendency toward drug resistance was observed. Rifampicin was the most potent drug followed by levofloxacin, while doxycycline and tetracycline were found to be the less active agents. Conclusion: Susceptibility testing of Legionella environmental isolates could be beneficial to notify resistance to antibiotics in the environment before it becomes evident in clinical strains.
Keywords: serogroup 1; E-test; antibiotic susceptibility testing; drug resistance; fluoroquinolones; macrolides; rifampicin; tetracyclines.