Antimicrobial resistance and plasmid detection in strains of the Bacteroides fragilis group

Avila-Campos, Mario Julio; Carvalho, Maria Auxiliadora Roque de; Magalhães, Paula Prazeres; Damasceno, Carlos Américo Veiga; Chartone-Souza, Edmar; Cisalpino, Eduardo Osório

doi:10.1590/S0036-46651993000100016

Abstracts

Resistant populations of the Bacteroides fragilis group bacteria (two reference ones and two isolated from human and Callithrix penicillata marmoset) were obtained by the gradient plate technique, to clindamycin, penicillin G, metronidazole and mercuric chloride. All the four tested strains were originaly susceptible to the four antimicrobial drugs at the breakpoint used in this study. MICs determination for the four cultures gave constant values for each antimicrobial, on the several steps by the gradient plate technique. The intestinal human B. fragilis strains showed three DNA bands, that could be representative of only two plasmids in the closed covalently circular (CCC) form with molecular weights of approximately 25 and 2.5 Md. The results do not permit an association between the presence of plasmid in the human strain with the susceptibility to the studied drugs. The four strains were ß-lactamase negative in the two methods used, and no particular chromosomal genetic resistance marker was demonstred. The resistance (MIC) observed, after contact with penicillin G and mercuric chloride, were two-fold in the four tested strains

Bacteroides fragilis group; Antimicrobial resistance; Plasmid DNA

Cepas resistentes de bactérias do grupo Bacteroides fragilis (2 isoladas de humano e de sagui Callithrix penicillata e 2 de referência) foram obtidas pela técnica da placa gradiente para clindamicina, penicilina G, metronidazol e bicloreto de mercúrio. Todas as quatro cepas testadas foram originalmente sensíveis às quatro drogas antimicrobianas em relação ao ponto crítico usado neste estudo. A determinação das CIMs para as quatro cepas testadas mostrou valores constantes para cada antimicrobiano nas diversas concentrações usadas nas placas gradientes. A cepa B. fragilis de origem humana apresentou três bandas de ADN que devem corresponder a apenas dois plasmídios circulares covalentemente fechados (CCC), com pesos moleculares de aproximadamente 25 e 2.5 Md. Não se detectou a produção de ß-lactamase em nenhuma das cepas nos dois métodos usados. Os resultados não permitem uma associação entre a presença de plasmídios na cepa humana com a susceptibilidade às drogas estudadas. As quatro cepas mostraram-se B-lactamase negativas nos dois métodos usados, não se demonstrando qualquer marcador genético de resistência cromossômica. A resistência observada (CIM), após contato com a penicilina G e bicloreto de mercúrio, foi duas vezes maior nas quatro cepas testadas

BRIEF COMMUNICATION

Antimicrobial resistance and plasmid detection in strains of the Bacteroides fragilis group

Resistência antimicrobiana e detecção de plasmídios em cepas do grupo Bacteroides fragilis

Mario Julio Avila-Campos^I; Maria Auxiliadora Roque de Carvalho^II; Paula Prazeres Magalhães^II; Carlos Américo Veiga Damasceno^II; Edmar Chartone-Souza^II; Eduardo Osório Cisalpino^II

^IDepartamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo,S.P.

^IIDepartamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte,M.G.

^{Address for correspondence} Address for correspondence: Profa. Maria Auxiliadora R. de Carvalho Departamento de Microbiologia,ICB/UFMG CEP. 30.161, Belo Horizonte,M.G., Brasil

SUMMARY

Resistant populations of the Bacteroides fragilis group bacteria (two reference ones and two isolated from human and Callithrix penicillata marmoset) were obtained by the gradient plate technique, to clindamycin, penicillin G, metronidazole and mercuric chloride. All the four tested strains were originaly susceptible to the four antimicrobial drugs at the breakpoint used in this study. MICs determination for the four cultures gave constant values for each antimicrobial, on the several steps by the gradient plate technique. The intestinal human B. fragilis strains showed three DNA bands, that could be representative of only two plasmids in the closed covalently circular (CCC) form with molecular weights of approximately 25 and 2.5 Md. The results do not permit an association between the presence of plasmid in the human strain with the susceptibility to the studied drugs. The four strains were ß-lactamase negative in the two methods used, and no particular chromosomal genetic resistance marker was demonstred. The resistance (MIC) observed, after contact with penicillin G and mercuric chloride, were two-fold in the four tested strains.

Key words: Bacteroides fragilis group; Antimicrobial resistance; Plasmid DNA.

RESUMO

Cepas resistentes de bactérias do grupo Bacteroides fragilis (2 isoladas de humano e de sagui Callithrix penicillata e 2 de referência) foram obtidas pela técnica da placa gradiente para clindamicina, penicilina G, metronidazol e bicloreto de mercúrio. Todas as quatro cepas testadas foram originalmente sensíveis às quatro drogas antimicrobianas em relação ao ponto crítico usado neste estudo. A determinação das CIMs para as quatro cepas testadas mostrou valores constantes para cada antimicrobiano nas diversas concentrações usadas nas placas gradientes. A cepa B. fragilis de origem humana apresentou três bandas de ADN que devem corresponder a apenas dois plasmídios circulares covalentemente fechados (CCC), com pesos moleculares de aproximadamente 25 e 2.5 Md. Não se detectou a produção de ß-lactamase em nenhuma das cepas nos dois métodos usados. Os resultados não permitem uma associação entre a presença de plasmídios na cepa humana com a susceptibilidade às drogas estudadas. As quatro cepas mostraram-se B-lactamase negativas nos dois métodos usados, não se demonstrando qualquer marcador genético de resistência cromossômica. A resistência observada (CIM), após contato com a penicilina G e bicloreto de mercúrio, foi duas vezes maior nas quatro cepas testadas.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

ACKNOWLEDGEMENTS

The authors would like to thank Dr Ari M. Siqueira and Dr Paul Shafee for critical leading of the manuscript, and Luzia Rosa Resende for technical help.

This work was supported by grants from CPq/UFMG, CNPq, and Finep.

Recebido para publicação em 2/10/1991

Aceito para publicação em 5/1/1993

1. FINEGOLD, S.M. - Anaerobes: problems and controversies in bacteriology, infections, and susceptibility testing. Rev. infect. Dis., 12: 223-229, 1990.
2. FONTAINE, E.A.; ABECK, D.; JOHSON, A.P. & TAYLOR-ROBINSON, D. - Detection of plasmids in strains of Bacteroides ureolyticus isolated from the genital tract. Letter. Appl. Microbiol., 6: 117-120, 1988.
3. HOLDEMAN, E.P. & MOORE, W.E.C. - Anaerobic Laboratory Manual. 4 ed. Virginia, Virginia Polytechnic Institute and State University, 1977.
4. LIVINGSTON, S.J.; KOMINOS, S.D. & YEE, R.B. - New medium for selection and presumptive identification of the Bacteroides fragilis group. J. clin. Microbiol., 7: 448-453, 1978.
5. MANCINI, C. & BEHME, R.J. - Transfer of multiple antibiotic resistance from Bacteroides fragilis to Escherichia coli. J. infect. Dis., 136: 597-600, 1977.
6. POLK, B.F. & KASPER, D.L. - Bacteroides fragilis subspecies in clinical isolates. Ann. Intern. Med., 86: 569-571, 1977.
7. PORTER, F.O.; SILVER, S.; ONG, C. & NAKAHARA, H. - Selection of mercurial resistance in hospital setting. Antimicrob. Agents Chemother., 22: 852-858, 1982.
8. RASHTCHIAN, A., DUBES, G.R. & BOOTH, S J. - Tetracycline-inducible transfer of tetracycline resistance in Bacteroides fragilis in the absence of detectable plasmid DNA. J. Bact., 150: 141-147, 1982.
9. RILEY, T.V. & MEE, B.J. - Susceptibility of Bacteroides spp. to heavy metals. Antimicrob. Agents Chemother., 6: 117-120, 1988.
10. SALYERS, A.A. - Bacteroides of the human lower intestinal tract. Ann. Rev. Microbiol., 38: 293-313, 1984.
11. SUTTER, V.L.; BARRY, A.L.; WILKINS, T.D. & ZABRANSKY, R.J. - Collaborative evaluation of a proposed reference dilution method of susceptibility testing of anaerobic bacteria. Antimicrob. Agents Chemother., 16: 495-502, 1979.
12. SUTTER, V.L.; CITRON, D.M. & FINEGOLD, S.M. - Wadsworth Anaerobic Bacteriology Manual. 3 ed. St. Louis, CV. Mosby, 1980.
13. SZYBALSKI, W. - Gradient plate technique for study of bacterial resistance. Science, 116: 46-48, 1959.
14. TALLY, F.P.; SNYDMAN, D.R.; GORBACH, S.L. & MALAMY, M.H. - Plasmid-mediated, transferable resistance to clindamycin and erythromycin in Bacteroides fragilis. J. infect. Dis., 139: 83-88, 1979.
15. THORNSBERRY, C. - Rapid iodometric test for b-lactamase in Neisseria gonorrhoeae and Haentophilus influenzae Atlanta, Department of Health, Education, and Welfare, 1979. (CDC Laboratory Update,CDC 80-42) (Handout).
16. THORNSBERRY, C. - Chromogenic cephalosporin test for b-lactamase in Neisseria gonorrhoeae and Haemophilus influenzae Atlanta, Department of Health, Education, and Welfare, 1979. (CDC Laboratory Update, CDC 80-42) (Handout).
17. WALLACE, B.L.; BRADLEY, J.E. & ROGOLSKI, M. - Plasmid analysis in clinical isolates of Bacteroides fragilis and other Bacteroides species. J. clin. Microbiol., 14: 383-388, 1981.

Address for correspondence:

Profa. Maria Auxiliadora R. de Carvalho

Departamento de Microbiologia,ICB/UFMG

CEP. 30.161, Belo Horizonte,M.G., Brasil

Publication Dates

Publication in this collection
11 Sept 2006
Date of issue
Feb 1993

History

Received
02 Oct 1991
Accepted
05 Jan 1993

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] 1. FINEGOLD, S.M. - Anaerobes: problems and controversies in bacteriology, infections, and susceptibility testing. Rev. infect. Dis., 12: 223-229, 1990.

[2] 2. FONTAINE, E.A.; ABECK, D.; JOHSON, A.P. & TAYLOR-ROBINSON, D. - Detection of plasmids in strains of Bacteroides ureolyticus isolated from the genital tract. Letter. Appl. Microbiol., 6: 117-120, 1988.

[3] 3. HOLDEMAN, E.P. & MOORE, W.E.C. - Anaerobic Laboratory Manual. 4 ed. Virginia, Virginia Polytechnic Institute and State University, 1977.

[4] 4. LIVINGSTON, S.J.; KOMINOS, S.D. & YEE, R.B. - New medium for selection and presumptive identification of the Bacteroides fragilis group. J. clin. Microbiol., 7: 448-453, 1978.

[5] 5. MANCINI, C. & BEHME, R.J. - Transfer of multiple antibiotic resistance from Bacteroides fragilis to Escherichia coli. J. infect. Dis., 136: 597-600, 1977.

[6] 6. POLK, B.F. & KASPER, D.L. - Bacteroides fragilis subspecies in clinical isolates. Ann. Intern. Med., 86: 569-571, 1977.

[7] 7. PORTER, F.O.; SILVER, S.; ONG, C. & NAKAHARA, H. - Selection of mercurial resistance in hospital setting. Antimicrob. Agents Chemother., 22: 852-858, 1982.

[8] 8. RASHTCHIAN, A., DUBES, G.R. & BOOTH, S J. - Tetracycline-inducible transfer of tetracycline resistance in Bacteroides fragilis in the absence of detectable plasmid DNA. J. Bact., 150: 141-147, 1982.

[9] 9. RILEY, T.V. & MEE, B.J. - Susceptibility of Bacteroides spp. to heavy metals. Antimicrob. Agents Chemother., 6: 117-120, 1988.

[10] 10. SALYERS, A.A. - Bacteroides of the human lower intestinal tract. Ann. Rev. Microbiol., 38: 293-313, 1984.

[11] 11. SUTTER, V.L.; BARRY, A.L.; WILKINS, T.D. & ZABRANSKY, R.J. - Collaborative evaluation of a proposed reference dilution method of susceptibility testing of anaerobic bacteria. Antimicrob. Agents Chemother., 16: 495-502, 1979.

[12] 12. SUTTER, V.L.; CITRON, D.M. & FINEGOLD, S.M. - Wadsworth Anaerobic Bacteriology Manual. 3 ed. St. Louis, CV. Mosby, 1980.

[13] 13. SZYBALSKI, W. - Gradient plate technique for study of bacterial resistance. Science, 116: 46-48, 1959.

[14] 14. TALLY, F.P.; SNYDMAN, D.R.; GORBACH, S.L. & MALAMY, M.H. - Plasmid-mediated, transferable resistance to clindamycin and erythromycin in Bacteroides fragilis. J. infect. Dis., 139: 83-88, 1979.

[15] 15. THORNSBERRY, C. - Rapid iodometric test for b-lactamase in Neisseria gonorrhoeae and Haentophilus influenzae Atlanta, Department of Health, Education, and Welfare, 1979. (CDC Laboratory Update,CDC 80-42) (Handout).

[16] 16. THORNSBERRY, C. - Chromogenic cephalosporin test for b-lactamase in Neisseria gonorrhoeae and Haemophilus influenzae Atlanta, Department of Health, Education, and Welfare, 1979. (CDC Laboratory Update, CDC 80-42) (Handout).

[17] 17. WALLACE, B.L.; BRADLEY, J.E. & ROGOLSKI, M. - Plasmid analysis in clinical isolates of Bacteroides fragilis and other Bacteroides species. J. clin. Microbiol., 14: 383-388, 1981.

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