Summary: Members of the Mycobacterium abscessus complex are emerging pathogens of increasing importance, causing both respiratory and soft tissue infections, but precise speciation is problematic. This study was performed to examine the subspecies and antibiotic susceptibility of M. abscessus complex isolates collected during 2013 at the statewide New South Wales Mycobacterium Reference Laboratory (NSW MRL), Australia. Mycobacterium abscessus subsp. abscessus accounted for more than half of all M. abscessus isolates (n = 24, 57.1%), and M. abscessus subsp. massiliense comprised the remainder of the isolates (n = 18, 42.9%). There were no M. abscessus subsp. bolletii isolates. The prevalence of antibiotic resistance to all antibiotics, apart from amikacin was high, with 26.3% of isolates being reliably susceptible to only amikacin. Most M. abscessus subsp. abscessus isolates (80%) demonstrated inducible clarithromycin resistance whereas the majority of M. abscessus subsp. massiliense isolates (94.4%) remained susceptible to clarithromycin. There was a good correlation between the erm(41) genotype and clarithromycin susceptibility results after 14 days of incubation for most isolates with only three exceptions. Further studies correlating in vitro susceptibility profiles with clinical outcomes of M. abscessus infections treated with combination antimicrobial therapy are warranted.
1Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research - Pathology West, Westmead Hospital, Westmead
2Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
Address for correspondence: Dr Kyra Y. L. Chua, Department of Microbiology and Immunology, The University of Melbourne, Parkville, Vic 3010, Australia. E-mail: firstname.lastname@example.org
Received 7 May, 2015
Revised 3 July, 2015
Accepted 8 July, 2015
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