Multilocus Sequence Typing Scheme versus Pulsed-Field Gel Electrophoresis for Typing Mycobacterium abscessus Isolates

Abstract

hOutbreaks of infections by rapidly growing mycobacteria following invasive procedures, such as ophthalmological, laparoscopic, arthroscopic, plastic, and cardiac surgeries, mesotherapy, and vaccination, have been detected in Brazil since 1998. Members of the Mycobacterium chelonae-Mycobacterium abscessus group have caused most of these outbreaks. As part of an epidemiological investigation, the isolates were typed by pulsed-field gel electrophoresis (PFGE). In this project, we performed a large-scale comparison of PFGE profiles with the results of a recently developed multilocus sequence typing (MLST) scheme for M. abscessus. Ninety-three isolates were analyzed, with 40 M. abscessus subsp. abscessus isolates, 47 M. abscessus subsp. bolletii isolates, and six isolates with no assigned subspecies. Forty-five isolates were obtained during five outbreaks, and 48 were sporadic isolates that were not associated with outbreaks. For MLST, seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH) were sequenced, and each isolate was assigned a sequence type (ST) from the combination of obtained alleles. The PFGE patterns of DraI-digested DNA were compared with the MLST results. All isolates were analyzable by both methods. Isolates from monoclonal outbreaks showed unique STs and indistinguishable or very similar PFGE patterns. Thirty-three STs and 49 unique PFGE patterns were identified among the 93 isolates. The Simpson's index of diversity values for MLST and PFGE were 0.69 and 0.93, respectively, for M. abscessus subsp. abscessus and 0.96 and 0.97, respectively, for M. abscessus subsp. bolletii. In conclusion, the MLST scheme showed 100% typeability and grouped monoclonal outbreak isolates in agreement with PFGE, but it was less discriminative than PFGE for M. abscessus.

Multidrug-Resistant Nontuberculous Mycobacteria Isolated from Cystic Fibrosis Patients

“…These results confirmed the elevated discriminatory power of this method for diversity studies of these species, as shown in previous studies (33,34).…”

Epidemiological investigation and successful management of a Burkholderia cepacia outbreak in a neurotrauma intensive care unit

“…Clonal relatedness was established on the basis of MLST analysis. Although pulsed field gel electrophoresis (PFGE) has historically been used to define outbreaks and clusters (Dizbay et al, 2009;De Smet et al, 2013), the technique is cumbersome, requiring dedicated equipment that is not widely available (Machado et al, 2014). Many recent studies have explored the potential of MLST as a tool for detailed investigation of outbreaks (Mali et al, 2017;Singhal et al, 2015;Wang et al, 2015;Sails et al, 2003).…”

“…Many recent studies have explored the potential of MLST as a tool for detailed investigation of outbreaks (Mali et al, 2017;Singhal et al, 2015;Wang et al, 2015;Sails et al, 2003). Also, studies comparing the results of MLST schemes to PFGE have shown 100% agreement between the two techniques (Machado et al, 2014). MLST is also the method of choice for typing BCC due to its ability to differentiate the species in BCC complex (Mahenthiralingam et al, 2008;Vandamme and Dawyndt, 2011;Gautam et al, 2016).…”

New Mycobacteroides abscessus subsp. massiliense strains with recombinant hsp65 gene laterally transferred from Mycobacteroides abscessus subsp. abscessus: Potential for misidentification of M. abscessus strains with the hsp65-based method

“…MLST analyses targeting seven housekeeping genes were applied to investigate the genetic diversity of the two putative recombinant strains. The seven target genes were argH (argininosuccinate lyase), cya (adenylate cyclase), glpK (glycerol kinase), gnd (6-phosphogluconate dehydrogenase), murC (UDP N-acetylmuramate-L-alanine ligase), pta (phosphate acetyltransferase) and purH (phosphoribosylaminoimidazole carboxylase ATPase subunit) [28, 29]. Also, erm (41)-targeted PCR was applied to the reference strain and to two Rec-mas-H strains [30, 31].…”