- Email: [email protected]
REPLY FROM DR SAMPAIO AND DR LEÃO
944 Clinical Microbiology and Infection, Volume 12 Number 9, September 2006
whether the combined results obtained with the different primers were as discriminative as those obtained with the techniques described above, as has been found by others, including ourselves. J. Esteban, N. Zamora and A. Ortiz Department of Clinical Microbiology, Fundacio´n Jime´nez Dı´az-UTE, Avenida Reyes Cato´licos 2, 28040 Madrid, Spain E-mail: [email protected]
performed with profiles obtained with RAPD1 and OPA2, control strain C6, epidemiologically unrelated to the outbreak, still clustered with the outbreak isolates. This is why we stated that PFGE and ERIC-PCR performed better than RAPD in terms of discriminating among the group of isolates and strains that we analysed [1]. J. L. M. Sampaio and S. C. Lea˜o Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Sa˜o Paulo, Rua Botucatu, 862 3 andar. 04023–062, Sa˜o Paulo, SP, Brazil. E-mail: [email protected]
REPLY FROM DR SAMPAIO AND ˜O DR LEA We thank Dr Esteban and colleagues for their interesting comments. We had the opportunity to read their article [4], and although it also evaluated other rapidly growing mycobacteria, our response here will be limited to Mycobacterium fortuitum. In brief, they investigated 16 M. fortuitum isolates using four different primers and a single method, RAPD, modified from the original protocol described by Zhang et al. [2]; however, ERIC-PCR or PFGE were not used. Consequently, we disagree with their claim that our results are not consistent with their own experience in this area, as this is limited to RAPD. We agree that RAPD analysis with different primer sets may improve clonality analysis, as described for Mycobacterium abscessus by Zhang et al. [2], although RAPD has never been adequately validated for any of the rapid growing mycobacteria as recommended by the consensus guidelines of the ESCMID Study Group for Epidemiological Markers [7]. We also tested M. fortuitum outbreak isolates and unrelated control strains with primer OPA2, but we did not follow the protocol of Zhang et al. [2], as this has not been validated for M. fortuitum. When a combined analysis was
REFERENCES 1. Sampaio JLM, Chimara E, Ferrazoli L et al. Application of four molecular typing methods for analysis of Mycobacterium fortuitum group strains causing post-mammaplasty infections. Clin Microbiol Infect 2006; 12: 142–149. 2. Zhang Y, Rajagopalan M, Brown BA, Wallace RJ. Randomly amplified polymorphic DNA PCR for comparison of Mycobacterium abscessus strains from nosocomial outbreaks. J Clin Microbiol 1997; 35: 3132–3139. 3. Power EGM. RAPD typing in microbiology: a technical review. J Hosp Infect 1996; 34: 247–265. 4. Esteban J, Ferna´ndez Roblas R, Garcı´a Cı´a JI, Zamora N, Ortiz A. Clinical significance and epidemiology of non-pigmented rapidly growing mycobacteria in a university hospital. J Infect 2006; in press. 5. Lai KK, Brown BA, Westerling JA, Fontecchio SA, Zhang Y, Wallace RJ. Long-term laboratory contamination by Mycobacterium abscessus resulting in two pseudo-outbreaks: recognition with use of random amplified polymorphic DNA (RAPD) polymerase chain reaction. Clin Infect Dis 1998; 27: 169–175. 6. Matsiota-Bernard P, Zinzendorf N, Onody C, Guenounou M. Comparison of clarithromycin-sensitive and clarithromycinresistant Mycobacterium avium strains isolated from AIDS patients during therapy regimens including clarithromycin. J Infect 2000; 40: 49–54. 7. Struelens MJ. Consensus guidelines for appropriate use and evaluation of microbial epidemiologic typing systems. Clin Microbiol Infect 1996; 2: 2–11.
2006 Copyright by the European Society of Clinical Microbiology and Infectious Diseases, CMI, 12, 941–944
whether the combined results obtained with the different primers were as discriminative as those obtained with the techniques described above, as has been found by others, including ourselves. J. Esteban, N. Zamora and A. Ortiz Department of Clinical Microbiology, Fundacio´n Jime´nez Dı´az-UTE, Avenida Reyes Cato´licos 2, 28040 Madrid, Spain E-mail: [email protected]
performed with profiles obtained with RAPD1 and OPA2, control strain C6, epidemiologically unrelated to the outbreak, still clustered with the outbreak isolates. This is why we stated that PFGE and ERIC-PCR performed better than RAPD in terms of discriminating among the group of isolates and strains that we analysed [1]. J. L. M. Sampaio and S. C. Lea˜o Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Sa˜o Paulo, Rua Botucatu, 862 3 andar. 04023–062, Sa˜o Paulo, SP, Brazil. E-mail: [email protected]
REPLY FROM DR SAMPAIO AND ˜O DR LEA We thank Dr Esteban and colleagues for their interesting comments. We had the opportunity to read their article [4], and although it also evaluated other rapidly growing mycobacteria, our response here will be limited to Mycobacterium fortuitum. In brief, they investigated 16 M. fortuitum isolates using four different primers and a single method, RAPD, modified from the original protocol described by Zhang et al. [2]; however, ERIC-PCR or PFGE were not used. Consequently, we disagree with their claim that our results are not consistent with their own experience in this area, as this is limited to RAPD. We agree that RAPD analysis with different primer sets may improve clonality analysis, as described for Mycobacterium abscessus by Zhang et al. [2], although RAPD has never been adequately validated for any of the rapid growing mycobacteria as recommended by the consensus guidelines of the ESCMID Study Group for Epidemiological Markers [7]. We also tested M. fortuitum outbreak isolates and unrelated control strains with primer OPA2, but we did not follow the protocol of Zhang et al. [2], as this has not been validated for M. fortuitum. When a combined analysis was
REFERENCES 1. Sampaio JLM, Chimara E, Ferrazoli L et al. Application of four molecular typing methods for analysis of Mycobacterium fortuitum group strains causing post-mammaplasty infections. Clin Microbiol Infect 2006; 12: 142–149. 2. Zhang Y, Rajagopalan M, Brown BA, Wallace RJ. Randomly amplified polymorphic DNA PCR for comparison of Mycobacterium abscessus strains from nosocomial outbreaks. J Clin Microbiol 1997; 35: 3132–3139. 3. Power EGM. RAPD typing in microbiology: a technical review. J Hosp Infect 1996; 34: 247–265. 4. Esteban J, Ferna´ndez Roblas R, Garcı´a Cı´a JI, Zamora N, Ortiz A. Clinical significance and epidemiology of non-pigmented rapidly growing mycobacteria in a university hospital. J Infect 2006; in press. 5. Lai KK, Brown BA, Westerling JA, Fontecchio SA, Zhang Y, Wallace RJ. Long-term laboratory contamination by Mycobacterium abscessus resulting in two pseudo-outbreaks: recognition with use of random amplified polymorphic DNA (RAPD) polymerase chain reaction. Clin Infect Dis 1998; 27: 169–175. 6. Matsiota-Bernard P, Zinzendorf N, Onody C, Guenounou M. Comparison of clarithromycin-sensitive and clarithromycinresistant Mycobacterium avium strains isolated from AIDS patients during therapy regimens including clarithromycin. J Infect 2000; 40: 49–54. 7. Struelens MJ. Consensus guidelines for appropriate use and evaluation of microbial epidemiologic typing systems. Clin Microbiol Infect 1996; 2: 2–11.
2006 Copyright by the European Society of Clinical Microbiology and Infectious Diseases, CMI, 12, 941–944