The survival of rare beneficial mutations can be extremely sensitive to the organism's life history and the trait affected by the mutation. Given the tremendous impact of bacteria in batch culture as a model system for the study of adaptation, it is important to understand the survival probability of beneficial mutations in these populations. Here we develop a life-history model for bacterial p...

The susceptibility of coliform bacteria and bacterial pathogens to free chlorine residuals was determined before and after incubation with amoebae and ciliate protozoa. Viability of bacteria was quantified to determine their resistance to free chlorine residuals when ingested by laboratory strains of Acanthamoeba castellanii and Tetrahymena pyriformis. Cocultures of bacteria and protozoa were i...

Acinetobacter baumannii is emerging as a leading global multiple-antibiotic-resistant nosocomial pathogen. The identity of genes essential for pathogenesis in a mammalian host remains largely unknown. Using transposon-directed insertion-site sequencing (TraDIS), we identified A. baumannii genes involved in bacterial survival in a leukopenic mouse model of bloodstream infection. Mice were inocul...

The pathogen virulence is traditionally thought to co-evolve as a result of reciprocal selection with its host organism. In natural communities, pathogens and hosts are typically embedded within a web of interactions with other species, which could affect indirectly the pathogen virulence and host immunity through trade-offs. Here we show that selection by predation can affect both pathogen vir...

Pseudomonas aeruginosa is known to invade epithelial cells during infection and in vitro. However, little is known of bacterial or epithelial factors modulating P. aeruginosa intracellular survival or replication after invasion, except that it requires a complete lipopolysaccharide core. In this study, real-time video microscopy revealed that invasive P. aeruginosa isolates induced the formatio...

aims: the internal unit and icu of hospitals are a suitable environment for growing of bacteria such as staphylococcus epidermidis, pseudomonas and acinetobacters. the aim of this study was to evaluate the efficacy of using disinfectants on bacterial remove in isfahan city, iran, hospitals. instrument & methods: this descriptive study was performed in isfahan city, iran, hospitals in 2015. 200 ...

Tuberculosis is a leading global killer that has not been effectively controlled to date. The ability of the causative agent, Mycobacterium tuberculosis, to become dormant is one of the major reasons for extended chemotherapeutic regimens and wide epidemicity. The underlying mechanisms of M. tuberculosis dormancy are not fully understood. In the present work, a LuxR family transcription factor ...

The pathogenesis of Mycobacterium tuberculosis is associated with its ability to survive inside the human host and the bacteria use a variety of mechanism to evade the host’s defence. A clearer understanding of the host–pathogen interaction is needed to follow the pathogenicity and virulence. Recent advances in the study of inter and intra-cellular communication in bacteria had prompted us to s...

This report describes a previously unrecognized role for bacterial surface layers as barriers that confer protection against antimicrobial peptides. As antimicrobial peptides exist in natural environments, S-layers may provide a bacterial survival mechanism that has been selected for through evolution.

MgtC is important for the survival of several bacterial pathogens in macrophages and for growth under magnesium limitation. Among eukaryotes, a gene homologous to mgtC was found only in the pathogenic fungus Aspergillus fumigatus. Our data show that the A. fumigatus MgtC (AfuMgtC) protein does not have the same function as the bacterial MgtC proteins.