Type IV pili (T4P) are surface-exposed fibers that mediate many functions in bacteria, including locomotion, adherence to host cells, DNA uptake (competence), and protein secretion and that can act as nanowires carrying electric current. T4P are composed of a polymerized protein, pilin, and their assembly apparatuses share protein homologs with type II secretion systems in eubacteria and the fl...

A rapid method for demonstration of gram-positive and gram-negative bacteria in milk is described. The technique is based on dilution of the sample in a medium, followed by filtration through a porous polysulfone membrane with a pore size retaining and concentrating bacteria from the sample. The bacteria concentrated on the surface of the membrane are stained with a cationic dye (toluidine blue...

introduction: thymbra spicata (t. spicata) is a conventional medicinal herb which is commonly used in the folklore medicine system of iran. aim of the study was to assess the antibacterial activity of the essential oil and hudroalcholic extract of the plant t. spicata on some important bacteria. materials & methods: the essential oil and extract of t. spicata were obtained by hydrodistillation ...

Background: Antibacterial proteins are widely expressed in snake venoms. Previously, we have isolated two immunodominant proteins with molecular weights of 14 and 65kD from the snake venom of Naja naja oxiana (N. oxiana). It was demonstrated that they had potent inhibitory effects against gram-positive bacteria, S. aureus and B. subtilis but were less effective against gram-negative bacteria, s...

Inflammatory bowel disease (IBD) is characterized by chronic and relapsing intestinal inflammation of unknown etiology, but immune activation by the commensal microbiota probably plays a major role. The two major categories of IBD are ulcerative colitis and Crohn’s disease. One fifth of the cases present in childhood and Sweden has a high and rising incidence of pediatric IBD. The aim of this t...

A total of 451 strains of gram-positive bacteria were identified with a prototype of the Gram-Positive Identification card used in conjunction with the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.). Of the species that the Gram-Positive Identification card is capable of identifying, 85% of staphylococcal, 50% of beta-hemolytic group A, B, C, F, and G streptococcal, 91% of group D st...

At some point in the evolution of life, the domain Bacteria arose from prokaryotic progenitors. The cell that gave rise to the first bacterium has been given the name (among several other names) "last universal ancestor (LUA)". This cell had an extensive, well-developed suite of biochemical strategies that increased its ability to grow. The first bacterium is thought to have acquired a covering...

Rapid identification and determination of the antibiotic susceptibility profiles of the infectious agents in patients with bloodstream infections are critical steps in choosing an effective targeted antibiotic for treatment. However, there has been minimal effort focused on developing combined methods for the simultaneous direct identification and antibiotic susceptibility determination of bact...

Bacteria are frequently exposed to a range of different circumstances in which the activation of adaptive mechanisms is essential for cell maintenance and survival. The modulation of such activity is intricately driven through gene regulation, involving diverse events at the transcriptional, translational, and posttranslational levels. Thus, transcription initiation could be considered the majo...