A novel PhoPQ-potentiated mechanism of colistin resistance impairs membrane integrity in .

Polymicrobial communities are often recalcitrant to antibiotic treatment because interactions between different microbes can dramatically alter their responses and susceptibility to antimicrobials. However, the mechanisms of evolving antimicrobial resistance in such polymicrobial environments are poorly understood. We previously reported that Mg depletion caused by the fungus can enable to acquire significant resistance to colistin, a last-resort antibiotic targeting bacterial membrane.

Widespread fungal-bacterial competition for magnesium lowers bacterial susceptibility to polymyxin antibiotics.

Fungi and bacteria coexist in many polymicrobial communities, yet the molecular basis of their interactions remains poorly understood. Here, we show that the fungus Candida albicans sequesters essential magnesium ions from the bacterium Pseudomonas aeruginosa. To counteract fungal Mg2+ sequestration, P.

Stickiness of extracellular polymeric substances on different surfaces via magnetic tweezers.

Organic particle dynamics in the surface ocean plays a critical part in the marine carbon cycle. Aggregation of marine organic particles drives their downward transport to support various marine organisms on their transit to the sediments. Extracellular polymeric substances (EPS) from various microbes are a major contributor to the oceanic organic particle pool.

Klotho Exerts an Emerging Role in Cytokinesis.

The Klotho gene functions as an anti-aging gene. A previous klotho-knockout mice study indicated that neither male nor female gametocytes could accomplish the first meiotic division. It suggested that Klotho might regulate cell division.

Hsp90 regulates nongenetic variation in response to environmental stress.

Nongenetic cell-to-cell variability often plays an important role for the survival of a clonal population in the face of fluctuating environments. However, the underlying mechanisms regulating such nongenetic heterogeneity remain elusive in most organisms. We report here that a clonal yeast population exhibits morphological heterogeneity when the level of Hsp90, a molecular chaperone, is reduced.

The evolution of low mutation rates in experimental mutator populations of Saccharomyces cerevisiae.

Mutation is the source of both beneficial adaptive variation and deleterious genetic load, fueling the opposing selective forces than shape mutation rate evolution. This dichotomy is well illustrated by the evolution of the mutator phenotype, a genome-wide 10- to 100-fold increase in mutation rate. This phenotype has often been observed in clonally expanding populations exposed to novel or frequently changing conditions.

Molecular packing and lateral interactions of distearoylphosphatidylcholine with dihexadecyldimethylammonium bromide in Langmuir monolayers and vesicles.

The behavior of distearoylphosphatidylcholine (DSPC) mixed with dihexadecyldimethylammonium bromide (DHDAB) in the monolayer was investigated by means of Langmuir trough, interfacial thermodynamic analysis, and Brewster angle microscopy. It was found that the cationic surfactant, DHDAB, was miscible with DSPC and a condensing effect, indicating stronger contraction of area per molecule and stronger ordering molecular packing, appeared in the mixed DSPC/DHDAB monolayers. Condensed structures of the mixed monolayers were visible as the molar fraction of DHDAB (X(DHDAB)) ≤ 0.