Mycobacterium massiliense BRA100 strain recovered from postsurgical infections: resistance to high concentrations of glutaraldehyde and alternative solutions for high level disinfection / Mycobacterium massiliense clone BRA100 associado a infecções pós-cirúrgicas: resistência a altas concentrações de glutaraldeído e produtos alternativos para desinfecção de alto nível

PURPOSE: To evaluate the minimum inhibitory concentration (MIC) of GTA against these microorganisms and alternative disinfectants for high-level disinfection (HLD). METHODS: Reference mycobacteria and clinical M. massiliense strains were included in this study. Active cultures were submitted to susceptibility qualitative tests with GTA dilutions (ranging from 1.5 percent to 8 percent), and commercial orthophthaldehyde (OPA) and peracetic acid (PA) - based solutions, during the period of exposure as recommended by National Agency of Sanitary Surveillance for HLD. RESULTS: All reference and M. massiliense non-BRA100 strains, recovered from sputum, were susceptible to any GTA concentration, OPA and PA solutions. M. massiliense BRA100 strains presented MIC of 8 percent GTA and were susceptible to OPA and PA. CONCLUSION: M. massiliense BRA100 strain is resistant to high GTA concentrations (up to 7 percent), which proves that this product is non-effective against specific rapidly growing mycobacteria and should be substituted by OPA or PA - based solutions for HLD.

OBJETIVO: Avaliar a concentração mínima inibitória (CMI) de GTA frente a M. massiliense e a susceptibilidade a produtos alternativos para desinfecção de alto nível (DAN). MÉTODOS: Cepas de M. massiliense de origem clínica e de referência foram incluídas no estudo. As culturas ativadas foram submetidas a testes qualitativos com diluições de GTA (de 1,5 por cento a 8 por cento) e com soluções comerciais de ortoftaldeído (OPA) ou ácido peracético (PA), utilizando os tempos de exposição recomendados pela Agência Nacional de Vigilância Sanitária para DAN. RESULTADOS: Todas as cepas de referência e M. massiliense não-BRA100, obtida de escarro, foram susceptíveis às concentrações de GTA, e soluções de OPA e PA. As cepas de M. massiliense BRA100 apresentaram CMI de 8 por cento para GTA e foram susceptíveis a OPA e PA. CONCLUSÃO: M. massiliense BRA100 é resistente a altas concentrações de GTA (até 7 por cento), o que demonstra que esse composto não é eficaz, e deve ser substituído por OPA ou PA nos processos de DAN.

Mycobacterium massiliense BRA100 strain recovered from postsurgical infections: resistance to high concentrations of glutaraldehyde and alternative solutions for high level disinfection.

PURPOSE: To evaluate the minimum inhibitory concentration (MIC) of GTA against these microorganisms and alternative disinfectants for high-level disinfection (HLD). METHODS: Reference mycobacteria and clinical M. massiliense strains were included in this study. Active cultures were submitted to susceptibility qualitative tests with GTA dilutions (ranging from 1.5% to 8%), and commercial orthophthaldehyde (OPA) and peracetic acid (PA)-based solutions, during the period of exposure as recommended by National Agency of Sanitary Surveillance for HLD. RESULTS: All reference and M. massiliense non-BRA100 strains, recovered from sputum, were susceptible to any GTA concentration, OPA and PA solutions. M. massiliense BRA100 strains presented MIC of 8% GTA and were susceptible to OPA and PA. CONCLUSION: M. massiliense BRA100 strain is resistant to high GTA concentrations (up to 7%), which proves that this product is non-effective against specific rapidly growing mycobacteria and should be substituted by OPA or PA-based solutions for HLD.

Infecção por micobactérias de crescimento rápido após procedimentos videocirúrgicos: a hipótese do glutaraldeído / Rapidly growing mycobacteria infection after videosurgical procedures: the glutaraldehyde hypothesis

Between August 2006 and February 2007, in the state of Rio de Janeiro, Brazil, a massive outbreak of RGM infections after video laparoscopy was mainly associated to the recently described Mycobacterium massiliense species. All confirmed and probable cases reports described the use of high-level disinfection of medical devices by using 2 percent glutaraldehyde (2 percent GA) for 30 min before the surgical procedures. We investigated the susceptibility of the M. massiliense isolates recovered during the outbreak to high-level disinfection after 30 min, 1h, 6h and 10h of exposure to the commercial disinfectants. Reference strains for official mycobactericidal tests such as Mycobacterium abscessus, Mycobacterium bovis, Mycobacterium chelonae, Mycobacterium neoaurum and Mycobacterium smegmatis were included as controls. Although all the reference strains were eliminated in 30 min of exposure to 2 percent GA, we observed the recovery of all M. massiliense clinical isolates even after 10h of exposure. This study suggests that failures in high-level disinfection and the high tolerance of these M. massiliense clinical strains to the 2 percent GA were strongly associated to the magnitude of the outbreak.

Epidemic of postsurgical infections caused by Mycobacterium massiliense.

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.

[Rapidly growing mycobacteria infection after videosurgical procedures - the glutaraldehyde hypothesis]. / Infecção por micobactérias de crescimento rápido após procedimentos videocirúrgicos - a hipótese do glutaraldeído.

Between August 2006 and February 2007, in the state of Rio de Janeiro, Brazil, a massive outbreak of RGM infections after video laparoscopy was mainly associated to the recently described Mycobacterium massiliense species. All confirmed and probable cases reports described the use of high-level disinfection of medical devices by using 2% glutaraldehyde (2% GA) for 30 min before the surgical procedures. We investigated the susceptibility of the M. massiliense isolates recovered during the outbreak to high-level disinfection after 30 min, 1h, 6h and 10h of exposure to the commercial disinfectants. Reference strains for official mycobactericidal tests such as Mycobacterium abscessus, Mycobacterium bovis, Mycobacterium chelonae, Mycobacterium neoaurum and Mycobacterium smegmatis were included as controls. Although all the reference strains were eliminated in 30 min of exposure to 2% GA, we observed the recovery of all M. massiliense clinical isolates even after 10h of exposure. This study suggests that failures in high-level disinfection and the high tolerance of these M. massiliense clinical strains to the 2% GA were strongly associated to the magnitude of the outbreak.