Epidemic of postsurgical infections caused by Mycobacterium massiliense

Abstract

An epidemic of infections after video-assisted surgery (1,051 possible cases) caused by rapidly growing mycobacteria (RGM) and involving 63 hospitals in the state of Rio de Janeiro, Brazil, occurred between August 2006 and July 2007. One hundred ninety-seven cases were confirmed by positive acid-fast staining and/or culture techniques. Thirty-eight hospitals had cases confirmed by mycobacterial culture, with a total of 148 available isolates recovered from 146 patients. Most (n = 144; 97.2%) isolates presented a PRA-hsp65 restriction pattern suggestive of Mycobacterium bolletii or Mycobacterium massiliense. Seventy-four of these isolates were further identified by hsp65 or rpoB partial sequencing, confirming the species identification as M. massiliense. Epidemic isolates showed susceptibility to amikacin (MIC at which 90% of the tested isolates are inhibited [MIC(90)], 8 microg/ml) and clarithromycin (MIC(90), 0.25 microg/ml) but resistance to ciprofloxacin (MIC(90), >or=32 microg/ml), cefoxitin (MIC(90), 128 microg/ml), and doxycycline (MIC(90), >or=64 microg/ml). Representative epidemic M. massiliense isolates that were randomly selected, including at least one isolate from each hospital where confirmed cases were detected, belonged to a single clone, as indicated by the analysis of pulsed-field gel electrophoresis (PFGE) patterns. They also had the same PFGE pattern as that previously observed in two outbreaks that occurred in other Brazilian cities; we designated this clone BRA100. All five BRA100 M. massiliense isolates tested presented consistent tolerance to 2% glutaraldehyde. This is the largest epidemic of postsurgical infections caused by RGM reported in the literature to date in Brazil.

FIG. 1.

Distribution of positive laboratory tests among 302 probable cases with notified laboratory diagnosis during the epidemic of RGM postsurgical infections in Rio de Janeiro, Brazil (2006 to 2007).

FIG. 2.

PRA-hsp65 profiles of six representative M. massiliense epidemic isolates. Lanes 1 and 15, 50-bp DNA ladder; lane 8, 25-bp DNA ladder; lanes 2 to 7, amplicons digested with BstEII; lanes 9 to 14, amplicons digested with HaeIII. Each lane represents a different strain: lane 2, CRM-0006; 3, CRM-0018; 4, CRM-0029; 5, CRM-0181; 6, CRM-0189; 7, CRM-0195; 9, CRM-0006; 10, CRM-0018; 11, CRM-0029; 12, CRM-0181; 13, CRM-0189; and 14, CRM-0195.

FIG. 3.

PFGE profiles of genomic DNA from M. massiliense isolates after digestion with DraI. Lanes 1 and 15, molecular size markers (Lambda DNA concatemers ranging from 48.5 to 1,018.5 kb); 2, CRM-0006; 3, CRM-0013; 4, CRM-0018; 5, CRM-0019; 6, CRM-0020; 7, CRM-0029; 8, CRM-0169, 9, CRM-0172; 10, CRM-0181; 11, CRM-0185; 12, CRM-0189; 13, CRM-0191; and 14, CRM-0195.

FIG. 4.

Dendrogram resulting from computer-assisted analysis of the PFGE profiles of 43 representative M. massiliense isolates. The Dice coefficient was used for calculating the percentages of similarity among the profiles. M. massiliense isolates recovered during outbreaks in other Brazilian cities are marked in bold. Diag., diagnosis. Footnotes: a, the mycobacterial isolate was recovered from a patient who submitted to video laparoscopic surgery headed by the Dr.n team; b, the mycobacterial isolate was obtained from a patient who submitted to surgery at hospital (H) n; c, RJ, Rio de Janeiro city; d, NR, not reported; e, NA, not applicable.