scholarly journals Antimycobacterial activity of 1-deaza-7,8-dihydropteridine derivatives against Mycobacterium tuberculosis and Mycobacterium avium complex in vitro

2001 ◽  
Vol 47 (4) ◽  
pp. 451-454 ◽  
Author(s):  
W. J. Suling
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Antimycobacterial Activity

scholarly journals Comparative In Vitro Antimicrobial Activities of the Newly Synthesized Quinolone HSR-903, Sitafloxacin (DU-6859a), Gatifloxacin (AM-1155), and Levofloxacin againstMycobacterium tuberculosis and Mycobacterium avium Complex

1999 ◽  
Vol 43 (12) ◽  
pp. 3001-3004 ◽  
Author(s):  
Haruaki Tomioka ◽  
Katsumasa Sato ◽  
Tatsuya Akaki ◽  
Hiroko Kajitani ◽  
Shin Kawahara ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Antimycobacterial Activity ◽  
Antimicrobial Activities ◽  
Type Ii ◽  
Alveolar Cells ◽  
Strong Activity ◽  
Type Ii Alveolar Cells ◽  
Gram Positive Cocci

ABSTRACT We compared the in vitro antimycobacterial activity of a new fluoroquinolone, HSR-903, with strong activity against gram-positive cocci with those of levofloxacin (LVFX), sitafloxacin (STFX), and gatifloxacin (GFLX). The MICs of the quinolones for Mycobacterium tuberculosis and Mycobacterium avium complex were in the order STFX ≈ GFLX < LVFX ≦ HSR-903 and STFX ≦ GFLX ≦ HSR-903 ≦ LVFX, respectively. HSR-903 effectively eliminated intramacrophagial M. tuberculosis, as did LVFX, and exhibited bacteriostatic effects against M. tuberculosis replicating in type II alveolar cells.

On the Relationship between the Structure and Antimycobacterial Activity of Substituted N-Benzylsalicylamides

2003 ◽  
Vol 68 (7) ◽  
pp. 1275-1294 ◽  
Author(s):  
Karel Waisser ◽  
Milan Peřina ◽  
Věra Klimešová ◽  
Jarmila Kaustová
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Avium ◽  
Antimycobacterial Activity ◽  
Acyl Moiety ◽  
Mycobacterium Kansasii ◽  
Hammett Constants ◽  
Substituent Constants ◽  
The Relationship ◽  
Lipophilicity Parameters

Sixty-six N-benzylsalicylamides substituted in the acyl moiety in positions 3, 4 or 5 and in position 4 on the benzylic aromatic ring were synthesized. The compounds were tested for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. To evaluate structure-antimycobacterial activity relationships (QSARs), approaches based on the Free-Wilson as well as a combination of the Free-Wilson and Hansch methods were employed (substituent constants were used to describe the influence of the benzyl substituents, indicator parameters were used for the substituents on the acyl moiety). The use of the Hammett constants for benzyl substituents was not important for QSAR equations. The quadratic representation of lipophilicity parameters (π2) was significant only in QSAR equations of antimycobacterial activity against M. avium.

scholarly journals Biofilm formation in the lung contributes to virulence and drug tolerance of Mycobacterium tuberculosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Poushali Chakraborty ◽  
Sapna Bajeli ◽  
Deepak Kaushal ◽  
Bishan Dass Radotra ◽  
Ashwani Kumar
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Immune System ◽  
Biofilm Formation ◽  
Antimycobacterial Activity ◽  
Drug Tolerance ◽  
Host Immune System ◽  
Tissue Sections ◽  
Slow Growing

AbstractTuberculosis is a chronic disease that displays several features commonly associated with biofilm-associated infections: immune system evasion, antibiotic treatment failures, and recurrence of infection. However, although Mycobacterium tuberculosis (Mtb) can form cellulose-containing biofilms in vitro, it remains unclear whether biofilms are formed during infection in vivo. Here, we demonstrate the formation of Mtb biofilms in animal models of infection and in patients, and that biofilm formation can contribute to drug tolerance. First, we show that cellulose is also a structural component of the extracellular matrix of in vitro biofilms of fast and slow-growing nontuberculous mycobacteria. Then, we use cellulose as a biomarker to detect Mtb biofilms in the lungs of experimentally infected mice and non-human primates, as well as in lung tissue sections obtained from patients with tuberculosis. Mtb strains defective in biofilm formation are attenuated for survival in mice, suggesting that biofilms protect bacilli from the host immune system. Furthermore, the administration of nebulized cellulase enhances the antimycobacterial activity of isoniazid and rifampicin in infected mice, supporting a role for biofilms in phenotypic drug tolerance. Our findings thus indicate that Mtb biofilms are relevant to human tuberculosis.

In vitro synergistic interactions of oleanolic acid in combination with isoniazid, rifampicin or ethambutol against Mycobacterium tuberculosis

2010 ◽  
Vol 59 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Fa Ge ◽  
Fanli Zeng ◽  
Siguo Liu ◽  
Na Guo ◽  
Haiqing Ye ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Oleanolic Acid ◽  
Antimycobacterial Activity ◽  
Vero Cells ◽  
Drug Resistant ◽  
Synergistic Interactions ◽  
Combination Treatments ◽  
Low Cytotoxicity ◽  
Drug Resistant Strains

Reports have shown that oleanolic acid (OA), a triterpenoid, exists widely in food, medicinal herbs and other plants, and that it has antimycobacterial activity against the Mycobacterium tuberculosis strain H37Rv (ATCC 27294). In this study it was found that OA had antimycobacterial properties against eight clinical isolates of M. tuberculosis and that the MICs of OA against drug-sensitive and drug-resistant isolates were 50–100 and 100–200 μg ml−1, respectively. The combination of OA with isoniazid (INH), rifampicin (RMP) or ethambutol (EMB) showed favourable synergistic antimycobacterial effects against six drug-resistant strains, with fractional inhibitory concentration indices of 0.121–0.347, 0.113–0.168 and 0.093–0.266, respectively. The combination treatments of OA/INH, OA/RMP and OA/EMB displayed either a synergistic interaction or did not show any interaction against two drug-sensitive strains. No antagonism resulting from the OA/INH, OA/RMP or OA/EMB combination was observed for any of the strains tested. OA exhibited a relatively low cytotoxicity in Vero cells. These results indicate that OA may serve as a promising lead compound for future antimycobacterial drug development.

scholarly journals Ambroxol Induces Autophagy and Potentiates Rifampin Antimycobacterial Activity

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Seong Won Choi ◽  
Yuexi Gu ◽  
Ryan Scott Peters ◽  
Padmini Salgame ◽  
Jerrold J. Ellner ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antimycobacterial Activity ◽  
Lead Compound ◽  
Content Type ◽  
Tuberculosis Model

ABSTRACT Host-directed therapy in tuberculosis is a potential adjunct to antibiotic chemotherapy directed at Mycobacterium tuberculosis. Ambroxol, a lead compound, emerged from a screen for autophagy-inducing drugs. At clinically relevant doses, ambroxol induced autophagy in vitro and in vivo and promoted mycobacterial killing in macrophages. Ambroxol also potentiated rifampin activity in a murine tuberculosis model.

scholarly journals The 8-Pyrrole-Benzothiazinones Are Noncovalent Inhibitors of DprE1 from Mycobacterium tuberculosis

2015 ◽  
Vol 59 (8) ◽  
pp. 4446-4452 ◽  
Author(s):  
Vadim Makarov ◽  
João Neres ◽  
Ruben C. Hartkoorn ◽  
Olga B. Ryabova ◽  
Elena Kazakova ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nitro Group ◽  
Covalent Bond ◽  
Antimycobacterial Activity ◽  
Content Type ◽  
Sar Studies ◽  
Covalent Bond Formation

ABSTRACT8-Nitro-benzothiazinones (BTZs), such as BTZ043 and PBTZ169, inhibit decaprenylphosphoryl-β-d-ribose 2′-oxidase (DprE1) and display nanomolar bactericidal activity againstMycobacterium tuberculosisin vitro. Structure-activity relationship (SAR) studies revealed the 8-nitro group of the BTZ scaffold to be crucial for the mechanism of action, which involves formation of a semimercaptal bond with Cys387 in the active site of DprE1. To date, substitution of the 8-nitro group has led to extensive loss of antimycobacterial activity. Here, we report the synthesis and characterization of the pyrrole-benzothiazinones PyrBTZ01 and PyrBTZ02, non-nitro-benzothiazinones that retain significant antimycobacterial activity, with MICs of 0.16 μg/ml againstM. tuberculosis. These compounds inhibit DprE1 with 50% inhibitory concentration (IC50) values of <8 μM and present favorablein vitroabsorption-distribution-metabolism-excretion/toxicity (ADME/T) andin vivopharmacokinetic profiles. The most promising compound, PyrBTZ01, did not show efficacy in a mouse model of acute tuberculosis, suggesting that BTZ-mediated killing through DprE1 inhibition requires a combination of both covalent bond formation and compound potency.

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