Analysis of Mycobacterium avium Complex Serovars Isolated from AIDS Patients from Southeast Brazil
Vol. 92(4): 471-475
Maria Helena Féres Saad/+,
Veronique Vincent*, David J Dawson**,
Moisés Palaci*** , Lucilaine Ferrazoli***, Leila de S
Fonseca****
Laboratório de Hanseníase, Instituto
Oswaldo Cruz, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ,
Brasil *Institut Pasteur, Centre Nationale de Reference pour les
Mycobactéries, Paris, France **Queensland Health, Laboratory of
Microbiology and Pathology, Brisbane, Australia ***Instituto
Adolfo Lutz, Laboratório de Referência para Micobactérias,
São Paulo, Brasil ****Instituto de Microbiologia, Universidade
Federal do Rio de Janeiro, RJ, Brasil
The purpose of this study was to assess the distribution of Mycobacterium avium serovars isolated from AIDS patients in São Paulo and Rio de Janeiro. Ninety single site or multiple site isolates from 75 patients were examined. The most frequent serovars found were 8 (39.2%), 4 (21.4%) and 1 (10.7%). The frequency of mixed infections with serovar 8 or 4 was 37.8%. Among the 90 strains examined, M. intracellulare serovars (7 strains) and M. scrofulaceum (4 strains) were found in 11 isolates (12%) indicating that M. avium (88%) was the major opportunistic species in the M. avium complex isolates in Brazilian AIDS patients.
Key words: seroagglutination - serovars - mycoside C - glicopeptidolipids - Mycobacterium avium
Non tuberculous mycobacteria belonging to the Mycobacterium avium complex (MAC) have been increasingly recognized as an important group of organisms causing severe opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS) in the United States (Kiehn et al. 1985, Young et al. 1986, Horsburgh & Selik 1989, Nassos et al. 1991, Havlik et al. 1992), Europe (Yates et al. 1986, Wickman 1986, Peters et al. 1989, Grange et al. 1990) and Australia (Dawson 1990). In Brazil an increase in the frequency of M. avium complex infections has also been found associated with AIDS patients (Barreto et al. 1993, Landgraf et al. 1994). Recognition of the importance of MAC infection in AIDS has stimulated epidemiological studies concerning it. Most of the studies have been done in the USA, some in Europe; however none in Brazil.
MAC may be typed by using a seroagglutina-tion assay described by Schaefer (1965). Currently the serovars 1 through 6, 8 through 11 and 21 are recognized as M. avium, 7, 12 through 28 as M. intracellulare while serotypes 41 through 43 are designated M. scrofulaceum. Serotyping is based on the presence of specific oligosaccharide haptens (Brennan & Goren 1979, Brennan et al. 1981, McNeil et al. 1987) that form the sugar moiety of glycopeptidolipids (GPL), located on the cell surface of smooth-colony-forming strains. Rough colony variants are not amenable for serotyping because they agglutinate spontaneously. However, their GPL can be extracted and analyzed by thin layer chromatography (TLC) procedures (Brennan & Goren 1979).
Significant geographic differences have been reported in the major serotypes infecting AIDS patients (Kiehn et al. 1985, Horsburgh et al 1986). Furthermore, these serotypes infecting AIDS patients also differ from those predominantly infecting non-AIDS patients (Yakrus & Good 1990, Tsang et al. 1992).
In order to examine the predominant serotypes infecting patients, we analyzed MAC strains isolated from AIDS patients combining both agglutination according to Schaefer (1980) and the nature of the GPLs identified by TLC. The MAC strains were isolated from São Paulo and Rio de Janeiro, where the rate of AIDS infection is the highest in Brazil (Ministério da Saúde 1996).
ACKNOWLEDGEMENTS
To Dr Angela W Barreto and Dr Fátima Martins from Centro de Referência Prof. Hélio Fraga, and Dr Fátima Fandinho and Cristina L Almeida from Fundação Oswaldo Cruz, for supplying several of the clinical Mycobacterium avium complex isolates for analysis. To Dr Hugo David from Instituto de Higiene e Medicina, Universidade de Lisboa, Portugal for reviewing the manuscript. To Anne Varnerot from Institute Pasteur for technical advice.
This work was supported by CNPq and FINEP (Brasil).
+Corresponding author. Fax: +55-21-270.9997. E- mail: Saad@gene.dbbm.fiocruz.br
Received 4 December 1996
Accepted 22 April 1997
