Staphylococcus aureus and Pseudomonas aeruginosa Isolates from the Same Cystic Fibrosis Respiratory Sample Coexist in Coculture.

Respiratory infections with bacterial pathogens remain the major cause of morbidity in individuals with the genetic disease cystic fibrosis (CF). Some studies have shown that CF patients that harbor both Staphylococcus aureus and Pseudomonas aeruginosa in their lungs are at even greater risk for more severe and complicated respiratory infections and earlier death. However, the drivers for this worse clinical condition are not well understood.

Cystic Fibrosis Sputum Impairs the Ability of Neutrophils to Kill .

Cystic fibrosis (CF) airway disease is characterized by chronic microbial infections and infiltration of inflammatory polymorphonuclear (PMN) granulocytes. is a major lung pathogen in CF that persists despite the presence of PMNs and has been associated with CF lung function decline. While PMNs represent the main mechanism of the immune system to kill , it remains largely unknown why PMNs fail to eliminate in CF.

Genotypic and Phenotypic Diversity of Staphylococcus aureus Isolates from Cystic Fibrosis Patient Lung Infections and Their Interactions with Pseudomonas aeruginosa.

has recently overtaken as the most commonly recognized bacterial pathogen that infects the respiratory tracts of individuals with the genetic disease cystic fibrosis (CF) in the United States. Most studies of in CF patient lung infections have focused on a few isolates, often exclusively laboratory-adapted strains, and how they are killed by Less is known about the diversity of CF patient lung isolates in terms of both their virulence and their interaction with To begin to address this gap, we recently sequenced 64 clinical isolates and a reference isolate, JE2. Here, we analyzed the antibiotic resistance genotypes, sequence types, clonal complexes, types, types, and presence/absence of other known virulence factor genes of these isolates.

Whole-Genome Sequences of Staphylococcus aureus Isolates from Cystic Fibrosis Lung Infections.

Staphylococcus aureus is an early colonizer in the lungs of individuals with cystic fibrosis (CF), but surprisingly, only a limited number of genomes from CF-associated S. aureus isolates have been sequenced. Here, we present the whole-genome sequences of 65 S.

Diversity of Clinical and Environmental Isolates of Vibrio cholerae in Natural Transformation and Contact-Dependent Bacterial Killing Indicative of Type VI Secretion System Activity.

The bacterial pathogen Vibrio cholerae can occupy both the human gut and aquatic reservoirs, where it may colonize chitinous surfaces that induce the expression of factors for three phenotypes: chitin utilization, DNA uptake by natural transformation, and contact-dependent bacterial killing via a type VI secretion system (T6SS). In this study, we surveyed a diverse set of 53 isolates from different geographic locales collected over the past century from human clinical and environmental specimens for each phenotype outlined above. The set included pandemic isolates of serogroup O1, as well as several serogroup O139 and non-O1/non-O139 strains.

Vibrio cholerae: Measuring Natural Transformation Frequency.

Many bacteria can become naturally competent to take up extracellular DNA across their outer and inner membranes by a dedicated competence apparatus. Whereas some studies show that the DNA delivered to the cytoplasm may be used for genome repair or for nutrition, it can also be recombined onto the chromosome by homologous recombination: a process called natural transformation. Along with conjugation and transduction, natural transformation represents a mechanism for horizontal transfer of genetic material, e.

Competence and natural transformation in vibrios.

Natural transformation is a major mechanism of horizontal gene transfer in bacteria. By incorporating exogenous DNA elements into chromosomes, bacteria are able to acquire new traits that can enhance their fitness in different environments. Within the past decade, numerous studies have revealed that natural transformation is prevalent among members of the Vibrionaceae, including the pathogen Vibrio cholerae.

Natural competence in Vibrio cholerae is controlled by a nucleoside scavenging response that requires CytR-dependent anti-activation.

Competence for genetic transformation in Vibrio cholerae is triggered by chitin-induced transcription factor TfoX and quorum sensing (QS) regulator HapR. Transformation requires expression of ComEA, described as a DNA receptor in other competent bacteria. A screen for mutants that poorly expressed a comEA-luciferase fusion identified cytR, encoding the nucleoside scavenging cytidine repressor, previously shown in V.