Isolation and characterization of an uncoupler-resistant mutant of<i>Methanothermobacter thermautotrophicus</i>

Čuboňová, Ľubomíra; Šurín, Stanislav; Majerník, Alan I.; Šmigáň, P.

doi:10.1016/j.femsle.2004.01.033

Cited by 5 publications

(1 citation statement)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the spontaneous mutation assay, we were not able to detect a single S. aureus or E. faecium isolate with increased tolerance to JBC 1847, in contrast to the relatively high resistance frequencies of the same species against fusidic acid and, to a lesser extent, mupirocin (Table 1). The finding of these low spontaneous resistance frequencies of JBC 1847 is somewhat surprising, as bacterial resistance to uncouplers have been described numerous times for both Gram-positive and Gramnegative bacteria (Krulwich et al, 1990;Lewis et al, 1994;Čubopová et al, 2004). However, the multitarget activity of JBC 1847 as proposed by the results in the present study (uncoupling effect combined with inhibition of the histidine biosynthesis and nitrate reductase pathways) seems difficult for the bacteria to counteract with an increased tolerance response, as shown in the present study for single-step mutations and in a previous study using an induced tolerance (daily sub-culturing, low concentrations) assay (Ronco et al, 2020).…”

Section: Discussionmentioning

confidence: 98%

Insight Into the Anti-staphylococcal Activity of JBC 1847 at Sub-Inhibitory Concentration

et al. 2022

View full text Add to dashboard Cite

Multidrug-resistant pathogens constitute a serious global issue and, therefore, novel antimicrobials with new modes of action are urgently needed. Here, we investigated the effect of a phenothiazine derivative (JBC 1847) with high antimicrobial activity on Staphylococcus aureus, using a wide range of in vitro assays, flow cytometry, and RNA transcriptomics. The flow cytometry results showed that JBC 1847 rapidly caused depolarization of the cell membrane, while the macromolecule synthesis inhibition assay showed that the synthesis rates of DNA, RNA, cell wall, and proteins, respectively, were strongly decreased. Transcriptome analysis of S. aureus exposed to sub-inhibitory concentrations of JBC 1847 identified a total of 78 downregulated genes, whereas not a single gene was found to be significantly upregulated. Most importantly, there was downregulation of genes involved in adenosintrifosfat (ATP)-dependent pathways, including histidine biosynthesis, which is likely to correlate with the observed lower level of intracellular ATP in JBC 1847–treated cells. Furthermore, we showed that JBC 1847 is bactericidal against both exponentially growing cells and cells in a stationary growth phase. In conclusion, our results showed that the antimicrobial properties of JBC 1847 were primarily caused by depolarization of the cell membrane resulting in dissipation of the proton motive force (PMF), whereby many essential bacterial processes are affected. JBC 1847 resulted in lowered intracellular levels of ATP followed by decreased macromolecule synthesis rate and downregulation of genes essential for the amino acid metabolism in S. aureus. Bacterial compensatory mechanisms for this proposed multi-target activity of JBC 1847 seem to be limited based on the observed very low frequency of resistance toward the compound.

show abstract

Section: Discussionmentioning

confidence: 98%

Insight Into the Anti-staphylococcal Activity of JBC 1847 at Sub-Inhibitory Concentration

et al. 2022

View full text Add to dashboard Cite

show abstract

Biochemical characteristics of a mutant of the methanoarchaeonMethanothermobacter thermautotrophicus resistant to the protonophoric uncoupler TCS

2004

View full text Add to dashboard Cite

In an attempt to more closely define a protein basis of differences in ATPase and ATP synthase activities in a mutant of the methanoarchaeon Methanothermobacter thermautotrophicus resistant to the protonophoric uncoupler TCS (3,3',4',5-tetrachlorosalicylanilide), the composition of membrane associated proteins from the wild-type and mutant strains has been compared. The uncoupler-resistance in the mutant strain was not accompanied by changes in a protein size or changes in the level of subunits A, B and c (proteolipid) of the A1A0-type ATPase-synthase. On the other hand, we revealed a 670-kDa membrane-associated protein complex that is abundantly present only in the mutant strain; it is composed of at least 5 different subunits of 95, 52, 42, 29 and 22 kDa.

show abstract

Membrane proteins and squalene-hydrosqualene profile in methanoarchaeon Methanothermobacter thermautotrophicus resistant to N,N′-dicyclohexylcarbodiimide

et al. 2008

View full text Add to dashboard Cite

The biochemical basis of a defective bioenergetic system was attempted to be determined in N,N'-dicyclohexylcarbodiimide (DCCD)-resistant mutant of Methanothermobacter thermautotrophicus. Components participating in the maintenance of methanoarchaeal membrane structure and function, such as the composition of the mixture of squalene and its hydrosqualene derivatives and also properties of membrane-associated proteins were compared in wild-type and mutant cells. The impairment of the bioenergetic system in DCCD-resistant mutant was detectable in the membrane-protein profile; it was also accompanied by changes in proportions of squalene-hydrosqualenes.

show abstract

Isolation and characterization of an uncoupler-resistant mutant ofMethanothermobacter thermautotrophicus

Cited by 5 publications

References 38 publications

Insight Into the Anti-staphylococcal Activity of JBC 1847 at Sub-Inhibitory Concentration

Insight Into the Anti-staphylococcal Activity of JBC 1847 at Sub-Inhibitory Concentration

Biochemical characteristics of a mutant of the methanoarchaeonMethanothermobacter thermautotrophicus resistant to the protonophoric uncoupler TCS

Membrane proteins and squalene-hydrosqualene profile in methanoarchaeon Methanothermobacter thermautotrophicus resistant to N,N′-dicyclohexylcarbodiimide

Contact Info

Product

Resources

About