Screening of Several Anti-Infectives for in Vitro Activity against Mycobacterium smegmatis

Grace Lovia Allotey-Babington^1,2, Henry Nettey^1*, Philip Debrah¹, Ofosua Adi-Dako¹, Clement Sasu¹, Anastasia Antwi¹, Yvonne Darko¹, Newriza Nartey¹, Jida Asare¹

¹University of Ghana School of Pharmacy, Legon, Ghana.
²Mercer University School of Pharmacy, Atlanta, GA, USA.

DOI: 10.4236/aim.2014.416129                

Abstract

Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone or in combination against Mycobacterium smegmatis. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Minimum Inhibitory Concentrations (MIC) were obtained using the agar-well plate diffusion technique. Fractional Inhibitory Concentration Indices (FICI) were calculated for drug combinations using their MIC as obtained from the broth dilution method. Results: Of the thirty (30) anti-infective agents analyzed, ten (10) had MIC equivalent to or better than rifampicin (reference TB drug). Seven (7) drugs had MIC higher than rifampicin, while twelve (12) showed no growth inhibition of M. smegmatis. Analysis of the effect of drug combinations on M. smegmatis indicated that four (4) combinations, including rifampicin/ethambutol showed synergism. One (1) was additive, two (2) were indifferent and one (1) combination showed antagonism. Conclusion: Notable in the results obtained was the high effectiveness of the carbapenems in inhibiting the growth of M. smegmatis. Carbapenems, though not indicated for TB treatment, has a potential of playing a significant role in the treatment of tuberculosis. Also the drug combinations which showed synergism, especially those that involved the macrolide antibiotics, should further be investigated. These results have to be confirmed by in vivo clinical studies to define their roles in tuberculosis treatment.

Keywords

Antimicrobials, Minimum Inhibitory Concentration, M. smegmatis, Tuberculosis

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	North, R.J. and Jung, Y.-J. (2004) Immunity to Tuberculosis. Annual Review of Immunology, 22, 599-623.http://dx.doi.org/10.1146/annurev.immunol.22.012703.104635 http://www.ncbi.nlm.nih.gov/pubmed/15032590
[2]	Ducati, R.G., et al. (2006) The Resumption of Consumption—A Review on Tuberculosis. Memórias do Instituto Oswaldo Cruz, 101, 697-714. http://dx.doi.org/10.1590/S0074-02762006000700001 http://www.ncbi.nlm.nih.gov/pubmed/17160276
[3]	Russell, D.G., et al. (2009) Foamy Macrophages and the Progression of the Human Tuberculosis Granuloma. Nature Immunology, 10, 943-948. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2759071&tool=pmcentrez&rendertype=abstract
[4]	Zignol, M., et al. (2006) Global Incidence of Multidrug-Resistant Tuberculosis. The Journal of Infectious Diseases, 194, 479-485. http://dx.doi.org/10.1086/505877 http://www.ncbi.nlm.nih.gov/pubmed/16845631
[5]	Sareen, D., et al. (2003) Mycothiol Is Essential for Growth of Mycobacterium tuberculosis Erdman. Journal of Bacteriology, 185, 6736-6740. http://dx.doi.org/10.1128/JB.185.22.6736-6740.2003 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=262099&tool=pmcentrez&rendertype=ab stract
[6]	Parish, T. and Stoker, N.G. (2001) Mycobacterium tuberculosis Protocols. Humana Press, Clifton. http://link.springer.com/10.1385/1592591477
[7]	Shiloh, M.U. and Champion, P.A.D. (2010) To Catch a Killer. What Can Mycobacterial Models Teach Us about Mycobacterium tuberculosis Pathogenesis? Current Opinion in Microbiology, 13, 86-92. http://dx.doi.org/10.1016/j.mib.2009.11.006 http://www.sciencedirect.com/science/article/pii/S1369527409001775
[8]	Barry, C.E., et al. (2009) The Spectrum of Latent Tuberculosis: Rethinking the Biology and Intervention Strategies. Nature Reviews Microbiology, 7, 845-855. http://dx.doi.org/10.1038/nrmicro2236
[9]	Altaf, M., et al. (2010) Evaluation of the Mycobacterium smegmatis and BCG Models for the Discovery of Mycobacterium tuberculosis Inhibitors. Tuberculosis (Edinburgh, Scotland), 90, 333-337. http://dx.doi.org/10.1016/j.tube.2010.09.002 http://www.sciencedirect.com/science/article/pii/S1472979210001034
[10]	EUCAST of ESCMID (2000) EUCAST Definitive Document Terminology Relating to Methods for the Determination of Susceptibility of Bacteria to Antimicrobial Agents. Clinical Microbiology and Infection, 6, 503-508.
[11]	Orhan, G., et al. (2005) Synergy Tests by E Test and Checkerboard Methods of Antimicrobial Combinations against Brucella melitensis. Journal of Clinical Microbiology, 43, 140-143. http://dx.doi.org/10.1128/JCM.43.1.140-143.2005 http://jcm.asm.org/content/43/1/140.full#ref-3
[12]	Pankey, G.A. and Sabath, L.D. (2004) Clinical Relevance of Bacteriostatic versus Bactericidal Mechanisms of Action in the Treatment of Gram-Positive Bacterial Infections. Clinical Infectious Diseases, 38, 864-870. http://dx.doi.org/10.1086/381972 http://cid.oxfordjournals.org/content/38/6/864.full
[13]	Neal, M.J. (2010) Medical Pharmacology at a Glance, Custom. John Wiley & Sons, Hoboken. http://books.google.com.gh/books/about/Medical_Pharmacology_at_a_Glance_Custom.html?id=mj BaK0o0SIwC&pgis=1
[14]	Fernandes, P.B., et al. (1986) In Vitro and in Vivo Evaluation of A-56268 (TE-031), a New Macrolide. Antimicrobial agents and Chemotherapy, 30, 865-873. http://dx.doi.org/10.1128/AAC.30.6.865 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=180609&tool=pmcentrez&rendertype=ab stract
[15]	Haight, T.H. and Finland, M. (1952) Observations on Mode of Action of Erythromycin. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine, 81, 188-193.http://dx.doi.org/10.3181/00379727-81-19817 http://www.ncbi.nlm.nih.gov/pubmed/13047353
[16]	Piscitelli, S.C., Danziger, L.H. and Rodvold, K.A. (1992) Clarithromycin and Azithromycin: New Macrolide Antibiotics. Clinical Pharmacy, 11, 137-152. http://www.ncbi.nlm.nih.gov/pubmed/1312921
[17]	Heifets, L. and Lindholm-Levy, P. (1989) Comparison of Bactericidal Activities of Streptomycin, Amikacin, Kanamycin, and Capreomycin against Mycobacterium avium and M. Tuberculosis. Antimicrobial Agents and Chemotherapy, 33, 1298-1301. http://dx.doi.org/10.1128/AAC.33.8.1298
[18]	Nastro, L.J. and Finegold, S.M. (1972) Bactericidal Activity of Five Antimicrobial Agents against Bacteroides fragilis. Journal of Infectious Diseases, 126, 104-107. http://dx.doi.org/10.1093/infdis/126.1.104 http://jid.oxfordjournals.org/content/126/1/104.abstract?ijkey=0bf210afc1a0bce6e48e57950037e366e1510232&keytype2=tf_ipsecsha
[19]	Sande, M.A. and Johnson, M.L. (1975) Antimicrobial Therapy of Experimental Endocarditis Caused by Staphylococcus aureus. Journal of Infectious Diseases, 131, 367-375. http://dx.doi.org/10.1093/infdis/131.4.367 http://jid.oxfordjournals.org/content/131/4/367.abstract?ijkey=85e9131cb05e5ed9f5aa9b922cd7c6 7eeb8ad535&keytype2=tf_ipsecsha
[20]	Eghianruwa, K. (2014) Essential Drug Data for Rational Therapy in Veterinary Practice (Google eBook). AuthorHouse UK. http://books.google.com/books?id=CtfIAgAAQBAJ&pgis=1
[21]	Staines, H.M. and Krishna, S. (2012) Treatment and Prevention of Malaria: Antimalarial Drug Chemistry, Action and Use. Springer Basel AG, Basel. http://books.google.com/books?id=cNuY6tyyyrUC&pgis=1