Effects of clofazimine on planktonic and biofilm growth of Mycobacterium tuberculosis and Mycobacterium smegmatis

Mothiba, Maborwa Tebogo; Fourie, Bernard; Germishuizen, Willem Andreas; Cholo, Moloko C.

doi:10.1016/j.jgar.2014.12.001

Cited by 16 publications

(17 citation statements)

References 28 publications

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“…A bacterial inoculum was prepared as described, with minor modifications [ 16 ]. Briefly, a seed culture of Mtb cells was inoculated into 50 mL of 7H9-OGT broth and grown to mid-log phase at 37°C under stirring conditions.…”

Section: Methodsmentioning

confidence: 99%

“…Biofilm Quantification. The amounts of biofilm biomass in the CSC-treated and control cultures were quantified using a crystal violet-based staining procedure as described [16] with minor modifications. The supernatants, containing planktonic cells in the biofilm-forming cultures, were removed, and the residual biomass in the wells was washed once with 1 mL distilled water and air dried.…”

Section: Biomed Research Internationalmentioning

confidence: 99%

“…Determination of Bacterial Survival. Bacterial viability was determined using a colony-counting procedure as described [16,30]. The cultures were prepared as for measurement of growth.…”

Section: Biomed Research Internationalmentioning

confidence: 99%

“…During infection, a mixture of heterogenous populations of Mtb organisms is found in TB lesions, with actively-replicating(AR) bacilli located predominantly in macrophages, while persistent, slow-replicating (SR) and dormant, nonreplicating(NR) organisms are found in the central foci of granuloma lesions [11][12][13][14] and AR in macrophages that accumulate at the peripheral rim of the granuloma [13]. With respect to the in vitro setting, the AR, SR, and NR Mtb populations are found predominantly in planktonic, biofilmforming and preformed biofilm cultures, respectively [15,16].…”

Section: Introductionmentioning

confidence: 99%

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Effects of Cigarette Smoke Condensate on Growth and Biofilm Formation by Mycobacterium tuberculosis

Cholo

Rasehlo

Venter

et al. 2020

BioMed Research International

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Background and Objectives. Cigarette smoke (CS) is a major risk factor contributing to the burden of tuberculosis. Little is known, however, about the effects of CS exposure on growth and persistence of Mycobacterium tuberculosis (Mtb) organisms. This issue has been addressed in the current study, which is focused on the effects of cigarette smoke condensate (CSC) on the growth and viability of Mtb planktonic and biofilm-forming cultures. Materials and Methods. The planktonic and biofilm-forming cultures were prepared in Middlebrook 7H9 and Sauton broth media, respectively, using Mtb strain, H37Rv. The effects of CSC at concentrations of 0.05-3.12 mg/L on growth, biofilm formation and structure were evaluated using microplate Alamar Blue assay, spectrophotometric procedure and scanning electron microscopy (SEM), respectively. Involvement of reactive oxygen species in CSC-mediated biofilm formation was investigated by including catalase in biofilm-forming cultures. Results. CSC did not affect the growth of planktonic bacteria, but rather led to a statistically significant increase in biofilm formation at concentrations of 0.4-3.12 mg/L, as well as in the viability of biofilm-forming bacteria at CSC concentrations of 0.2-1.56 mg/L. SEM confirmed an agglomerated biofilm matrix and irregular bacterial morphology in CSC-treated biofilms. Inclusion of catalase caused significant attenuation of CSC-mediated augmentation of biofilm formation by Mtb, implying involvement of oxidative stress. These findings demonstrate that exposure of Mtb to CSC resulted in increased biofilm formation that appeared to be mediated, at least in part, by oxidative stress, while no effect on planktonic cultures was observed. Conclusion. Smoking-related augmentation of biofilm formation by Mtb may contribute to persistence of the pathogen, predisposing to disease reactivation and counteracting the efficacy of antimicrobial chemotherapy.

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Section: Methodsmentioning

confidence: 99%

Section: Biomed Research Internationalmentioning

confidence: 99%

“…Determination of Bacterial Survival. Bacterial viability was determined using a colony-counting procedure as described [16,30]. The cultures were prepared as for measurement of growth.…”

Section: Biomed Research Internationalmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Cigarette Smoke Condensate on Growth and Biofilm Formation by Mycobacterium tuberculosis

Cholo

Rasehlo

Venter

et al. 2020

BioMed Research International

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“…56 CLO exerts mainly bacteriostatic effects, while bactericidal actions against actively replicating bacilli are regarded as minor pharmacodynamic properties, with MIC values ranging from 0.06 to 2 µg/ml for M. tuberculosis. 52,57 With regard for M. avium, a CLO MIC of 0.12 µg/ml has been estimated in vitro. 58 The actual anti-mycobacterial activity of CLO remains unclear.…”

Section: Therapeutic Management Of Map Infectionmentioning

confidence: 99%