Complete identity and expression of StfZ, the -antisense RNA to the mRNA of the cell division gene , in .

Bacteria regulate FtsZ protein levels through transcriptional and translational mechanisms for proper cell division. A -antisense RNA, StfZ, produced from the intergenic region, was proposed to regulate FtsZ level in . However, its structural identity remained unknown.

A Nonclassical Mechanism of β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus and Its Effect on Virulence.

Methicillin-resistant Staphylococcus aureus (MRSA) is a group of pathogenic bacteria that are infamously resistant to β-lactam antibiotics, a property attributed to the gene. Recent studies have reported that mutations associated with the promoter region of demonstrated high levels of β-lactam resistance, suggesting the role of PBP4 as an important non- mediator of β-lactam resistance. The -promoter-associated mutations have been detected in strains with or without .

In Vivo Detection of Cyclic-di-AMP in .

Cyclic-di-AMP (CDA) is a signaling molecule that controls various cellular functions including antibiotic tolerance and osmoregulation in (). In this study, we developed a novel biosensor ( P6-4) for in vivo detection of CDA in . The fluorescent biosensor is based on a natural CDA riboswitch from connected at its P6 stem to the dye-binding aptamer Spinach.

The HO inherently released by the mycobacterial minor subpopulation enhances the survival of the major kin subpopulation against rifampicin.

Exposure to antibiotics most often generates oxidative stress in bacteria. Oxidative stress survival mechanisms would facilitate the evolution of antibiotic resistance. As part of an effort to understand oxidative stress survival mechanisms in mycobacteria, here we show that the minor subpopulation (s; hort-sized ells constituting 10% of the population) of significantly increased the survival of its major kin subpopulation (s; ormal/long-sized ells constituting 90% of the population) in the mid-log-phase (MLP) cultures against the oxidative stress induced by rifampicin and exogenously added HO (positive control).

Loss of GdpP Function in Staphylococcus aureus Leads to β-Lactam Tolerance and Enhanced Evolution of β-Lactam Resistance.

Infections caused by Staphylococcus aureus are a leading cause of mortality. Treating infections caused by S. aureus is difficult due to resistance against most traditional antibiotics, including β-lactams.

Mycobacterial Populations Partly Change the Proportions of the Cells Undergoing Asymmetric/Symmetric Divisions in Response to Glycerol Levels in Growth Medium.

Twenty to thirty percent of the septating mycobacterial cells of the mid-log phase population showed highly deviated asymmetric constriction during division (ACD), while the remaining underwent symmetric constriction during division (SCD). The ACD produced short-sized cells (SCs) and normal/long-sized cells (NCs) as the sister-daughter cells, but with significant differential susceptibility to antibiotic/oxidative/nitrite stress. Here we report that, at 0.

A Symmetric Molecule Produced by Mycobacteria Generates Cell-Length Asymmetry during Cell-Division and Thereby Cell-Length Heterogeneity.

Diadenosine polyphosphates, ApA, which contain two adenosines in a 5',5' linkage through phosphodiester bonds involving 2-7 phosphates, regulate diverse cellular functions in all organisms, from bacteria to humans, under normal and stress conditions. We had earlier reported consistent occurrence of asymmetric constriction during division (ACD) in 20-30% of dividing mycobacterial cells in culture, irrespective of different growth media, implying exogenous action of some factor of mycobacterial origin. Consistent with this premise, concentrated culture supernatant (CCS), but not the equivalent volume-wise concentrated unused medium, dramatically enhanced the ACD proportion to 70-90%.

Mycobacterial Cultures Contain Cell Size and Density Specific Sub-populations of Cells with Significant Differential Susceptibility to Antibiotics, Oxidative and Nitrite Stress.

The present study shows the existence of two specific sub-populations of and cells differing in size and density, in the id-og hase (MLP) cultures, with significant differential susceptibility to antibiotic, oxidative, and nitrite stress. One of these sub-populations (~10% of the total population), contained hort-sized ells (SCs) generated through highly-deviated asymmetric cell division (ACD) of normal/long-sized mother cells and symmetric cell divisions (SCD) of short-sized mother cells. The other sub-population (~90% of the total population) contained ormal/long-sized ells (NCs).

Highly Deviated Asymmetric Division in Very Low Proportion of Mycobacterial Mid-log Phase Cells.

In this study, we show that about 20% of the septating Mycobacterium smegmatis and Mycobacterium xenopi cells in the exponential phase populationdivideasymmetrically, with an unusually high deviation (17 ± 4%) in the division site from the median, to generate short cells and long cells, thereby generating population heterogeneity. This mode of division is very different from the symmetric division of themajority (about 80%) of the septating cells in the Mycobacterium smegmatis, Mycobacterium marinum, and Mycobacterium bovis BCG exponential phase population, with 5-10% deviation in the division site from the mid-cell site, as reported by recent studies. The short cells and the long cells further grew and divided to generate a population.

Asymmetric cell division in Mycobacterium tuberculosis and its unique features.

Recently, several reports showed that about 80 % of mid-log phase Mycobacterium smegmatis, Mycobacterium marinum, and Mycobacterium bovis BCG cells divide symmetrically with 5-10 % deviation in the septum position from the median. However, the mode of cell division of the pathogenic mycobacterial species, Mycobacterium tuberculosis, remained unclear. Therefore, in the present study, using electron microscopy, fluorescence microscopy of septum- and nucleoid-stained live and fixed cells, and live cell time-lapse imaging, we show the occurrence of asymmetric cell division with unusually deviated septum/constriction in 20 % of the 15 % septating M.