scholarly journals Meropenem-Clavulanic Acid Has HighIn VitroActivity against Multidrug-Resistant Mycobacterium tuberculosis

2015 ◽  
Vol 59 (6) ◽  
pp. 3630-3632 ◽  
Author(s):  
L. Davies Forsman ◽  
C. G. Giske ◽  
J. Bruchfeld ◽  
T. Schön ◽  
P. Juréen ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clavulanic Acid ◽  
Treatment Option ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Potential Treatment ◽  
Drug Resistant Tuberculosis ◽  
Content Type ◽  
Resistant Tuberculosis ◽  
Extensively Drug Resistant

ABSTRACTWe investigated the activity of meropenem-clavulanic acid (MEM-CLA) against 68Mycobacterium tuberculosisisolates. We included predominantly multi- and extensively drug-resistant tuberculosis (MDR/XDR-TB) isolates, since the activity of MEM-CLA for resistant isolates has previously not been studied extensively. Using Middlebrook 7H10 medium, all but four isolates showed an MIC distribution of 0.125 to 2 mg/liter for MEM-CLA, below the non-species-related breakpoint for MEM of 2 mg/liter defined by EUCAST. MEM-CLA is a potential treatment option for MDR/XDR-TB.

scholarly journals Intra- and Extracellular Activities of Trimethoprim-Sulfamethoxazole against Susceptible and Multidrug-Resistant Mycobacterium tuberculosis

2014 ◽  
Vol 58 (12) ◽  
pp. 7557-7559 ◽  
Author(s):  
L. Davies Forsman ◽  
T. Schön ◽  
U. S. H. Simonsson ◽  
J. Bruchfeld ◽  
M. Larsson ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Treatment Option ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Potential Treatment ◽  
Time Curve ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Concentration Time ◽  
Strain H37rv

ABSTRACTWe investigated the activity of trimethoprim-sulfamethoxazole (SXT) againstMycobacterium tuberculosis, the pathogen that causes tuberculosis (TB). The MIC distribution of SXT was 0.125/2.4 to 2/38 mg/liter for the 100 isolates tested, including multi- and extensively drug-resistant isolates (MDR/XDR-TB), whereas the intracellular MIC90of sulfamethoxazole (SMX) for the pansusceptible strain H37Rv was 76 mg/liter. In an exploratory analysis using a ratio of the unbound area under the concentration-time curve from 0 to 24 h over MIC (fAUC0–24/MIC) using ≥25 as a potential target, the cumulative fraction response was ≥90% at doses of ≥2,400 mg of SMX. SXT is a potential treatment option for MDR/XDR-TB.

scholarly journals Bazedoxifene Suppresses Intracellular Mycobacterium tuberculosis Growth by Enhancing Autophagy

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Qi Ouyang ◽  
Kehong Zhang ◽  
Dachuan Lin ◽  
Carl G. Feng ◽  
Yi Cai ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
New Host ◽  
Drug Resistant Tuberculosis ◽  
Content Type ◽  
Receptor Modulator ◽  
Resistant Tuberculosis ◽  
Negative Side Effects

ABSTRACT Tuberculosis (TB) is still the leading killer caused by Mycobacterium tuberculosis infection. There is a clear need for new treatment strategy against TB. It has been reported that tamoxifen, known as a selective estrogen receptor modulator (SERM), exhibits antimycobacterial activity and inhibits M. tuberculosis growth in macrophages. However, it remains unknown whether such antimicrobial activity is a general property of all SERMs and how it works. In this study, we identified that bazedoxifene (BZA), a newer SERM, inhibits intracellular M. tuberculosis growth in macrophages. BZA treatment increases autophagosome formation and LC3B-II protein expression in M. tuberculosis-infected macrophages. We further demonstrated that the enhancement of autophagy by BZA is dependent on increased reactive oxygen species (ROS) production and associated with phosphorylation of Akt/mTOR signaling. In summary, our data reveal a previously unappreciated antimicrobial function of BZA and suggest that future investigation focusing on the mechanism of action of SERMs in macrophages may lead to new host-directed therapies against TB. IMPORTANCE Since current strategies for the treatment of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) have low efficacy and highly negative side effects, research on new treatments including novel drugs is essential for curing drug-resistant tuberculosis. Host-directed therapy (HDT) has become a promising idea to modulate host cell responses to enhance protective immunity against pathogens. Bazedoxifene (BZA), which belongs to a new generation of SERMs, shows the ability to inhibit the growth of M. tuberculosis in macrophages and is associated with autophagy. Our findings reveal a previously unrecognized antibacterial function of BZA. We propose that the mechanism of SERMs action in macrophages may provide a new potential measure for host-directed therapies against TB.

scholarly journals Comparison of In Vitro Activity and MIC Distributions between the Novel Oxazolidinone Delpazolid and Linezolid against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis in China

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Zhaojing Zong ◽  
Wei Jing ◽  
Jin Shi ◽  
Shu'an Wen ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Novel Mutation ◽  
Multidrug Resistant ◽  
23S Rrna ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Significant Difference ◽  
Mdr Tb

ABSTRACT Oxazolidinones are efficacious in treating mycobacterial infections, including tuberculosis (TB) caused by drug-resistant Mycobacterium tuberculosis. In this study, we compared the in vitro activities and MIC distributions of delpazolid, a novel oxazolidinone, and linezolid against multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) in China. Additionally, genetic mutations in 23S rRNA, rplC, and rplD genes were analyzed to reveal potential mechanisms underlying the observed oxazolidinone resistance. A total of 240 M. tuberculosis isolates were included in this study, including 120 MDR-TB isolates and 120 XDR-TB isolates. Overall, linezolid and delpazolid MIC90 values for M. tuberculosis isolates were 0.25 mg/liter and 0.5 mg/liter, respectively. Based on visual inspection, we tentatively set epidemiological cutoff (ECOFF) values for MIC determinations for linezolid and delpazolid at 1.0 mg/liter and 2.0 mg/liter, respectively. Although no significant difference in resistance rates was observed between linezolid and delpazolid among XDR-TB isolates (P > 0.05), statistical analysis revealed a significantly greater proportion of linezolid-resistant isolates than delpazolid-resistant isolates within the MDR-TB group (P = 0.036). Seven (53.85%) of 13 linezolid-resistant isolates were found to harbor mutations within the three target genes. Additionally, 1 isolate exhibited an amino acid substitution (Arg126His) within the protein encoded by rplD that contributed to high-level resistance to linezolid (MIC of >16 mg/liter), compared to a delpazolid MIC of 0.25. In conclusion, in vitro susceptibility testing revealed that delpazolid antibacterial activity was comparable to that of linezolid. A novel mutation within rplD that endowed M. tuberculosis with linezolid, but not delpazolid, resistance was identified.

scholarly journals Use of fluorescein diacetate (FDA) staining to detect viable Mycobacterium tuberculosis

2012 ◽  
Vol 11 (4) ◽  
pp. 322-330 ◽  
Author(s):  
Shamima Islam ◽  
Farjana Rahman ◽  
Saurab Kisore Munshi ◽  
Jewel Ahmed ◽  
S M Mostafa Kamal ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Treatment Failure ◽  
Medical Science ◽  
Multidrug Resistant ◽  
Fluorescein Diacetate ◽  
Drug Resistant ◽  
Drug Resistant Tuberculosis ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Auramine O

Objective: Drug resistant tuberculosis has long been a common problem prevailing in developing countries including Bangladesh. Present study focused on the rapid identification of live Mycobacterium tuberculosis among treatment failure cases.Materials and Methods: Sputum samples from a total of 100 category-I and category-II treatment failure cases, assumed as multidrug resistant tuberculosis, were studied through fluorescein diacetate (FDA) staining under light emitting diode (LED) fluorescence microscope. Considering culture method as gold standard, we also compared the results of FDA staining with that of auramine O staining.Results: A total of 85% acid-fast bacilli were detected by FDA staining, 82% by auramine O staining and a total of 85% isolates were detected in Lowenstein-Jensen (LJ) culture. The sensitivity of FDA staining (96.47%) was estimated to be slightly higher than that of auramine O staining (91.76%). Moreover,76.47% cases were detected as multidrug resistant tuberculosis (MDR-TB). Conclusion: Taken together, FDA staining method has been proposed to be appropriate for the rapid diagnosis of drug resistant tuberculosis. DOI: http://dx.doi.org/10.3329/bjms.v11i4.12605 Bangladesh Journal of Medical Science Vol. 11 No. 04 Oct’12

scholarly journals Tuberculose Multirresistente por Estirpes da Família Beijing, em Doentes de Lisboa, Portugal: Estudo Preliminar

2017 ◽  
Vol 30 (3) ◽  
pp. 175 ◽  
Author(s):  
Fernando Maltez ◽  
Teresa Martins ◽  
Diana Póvoas ◽  
João Cabo ◽  
Helena Peres ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Past History ◽  
Multidrug Resistant ◽  
Resistance Pattern ◽  
Drug Resistant ◽  
Beijing Family ◽  
Resistant Tuberculosis ◽  
Extensively Drug Resistant ◽  
Number Of Patients ◽  
Drug Resistant Strains

Introduction: Beijing family strains of Mycobacterium tuberculosis are associated with multidrug-resistance. Although strains of the Lisboa family are the most common among multidrug-resistant and extensively drug-resistant patients in the region, several studies have reported the presence of the Beijing family. However, the features of patients from whom they were isolated, are not yet known.Material and Methods: Retrospective study involving 104 multidrug-resistant and extensively drug-resistant strains of Mycobacterium tuberculosis, from the same number of patients, isolated and genotyped between 1993 and 2015 in Lisbon. We assessed the prevalence of strains of both families and the epidemiologic and clinical features of those infected with Beijing family strains.Results: Seventy-four strains (71.2%) belonged to the Lisboa family, 25 (24.0%) showed a unique genotypic pattern and five (4.8%) belonged to the Beijing family, the latter identified after 2009. Those infected with Beijing family strains were angolan (n = 1), ukrainian (n = 2) and portuguese (n = 2), mainly young-aged and, four of five immunocompetent and with no past history of tuberculosis. All had multidrug-resistant tuberculosis. We did not find any distinctive clinical or radiological features, neither a predominant resistance pattern. Cure rate was high (four patients).Discussion: Although the number of infected patients with Beijing strains was small, it suggests an important proportion of primary tuberculosis, a potential for transmission in the community but also a better clinical outcome when compared to other reported strains, such as W-Beijing and Lisboa.Conclusion: Although Lisboa family strains account for most of the multidrug and extensively drug-resistant tuberculosis cases in Lisbon area, Beijing strains are transmitted in the city and might change the local characteristics of the epidemics.

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