Neisseria gonorrhoeae is an obligate human pathogen that colonizes the genital tract and causes gonorrhoea. Neisseria gonorrhoeae can form biofilms during natural cervical infections, on glass and in continuous flow-chamber systems. These biofilms contain large amounts of extracellular DNA, which plays an important role in biofilm formation. Many clinical isolates contain a gonococcal genetic i...

The Brucella abortus type IV secretion system (T4SS), encoded by the virB operon, is essential for establishing persistent infection in the murine reticuloendothelial system. To gain insight into the in vivo interactions mediated by the T4SS, we compared host responses elicited by B. abortus with those of an isogenic mutant in the virB operon. Mice infected with the B. abortus virB mutant elici...

Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA) was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular sur...

The aim of this study was to develop a Turkish version of the Turkish Pediatric Rhinitis Quality of Life Questionnaire (PRQLQ) that is conceptually equivalent to the original and to evaluate its validity and reliability. The study included 102 children with allergic rhinitis (AR) aged 5 to 16 years. Demographic information, family history of allergy, and duration of AR were recorded. All patien...

We have studied the evolution of a type IV secretion system (T4SS), in Bartonella, which is thought to have changed function from conjugation to erythrocyte adherence following a recent horizontal gene transfer event. The system, called Trw, is unique among T4SSs in that genes encoding both exo- and intracellular components are located within the same duplicated fragment. This provides an oppor...

Helicobacter pylori infects nearly half the world's population and is associated with a spectrum of gastric maladies. Infections with cytotoxin-associated gene pathogenicity island (cag PAI)-containing strains are associated with an increased risk for gastric cancer. The cag PAI contains genes encoding a type IV secretion system (T4SS) and a delivered effector, CagA, that becomes tyrosine phosp...

Type IV secretion systems (T4SS) are multiprotein structures that direct the translocation of specific molecules across the bacterial cell envelope. As in other bacteria, pathogenicity of the genus Brucella essentially depends on the integrity of the T4SS-encoding virB operon, whose expression is regulated by multiple transcription factors belonging to different families. Previously, we identif...

The duodenal ulcer promoting (dupA) gene, located in the plasticity region of Helicobacter pylori, is associated with duodenal ulcer development. dupA was predicted to form a type IV secretory system (T4SS) with vir genes around dupA (dupA cluster). We investigated the prevalence of dupA and dupA clusters and clarified associations between the dupA cluster status and clinical outcomes in the U....

BACKGROUND Biofilm formation by Helicobacter pylori may be one of the factors influencing eradication outcome. However, genetic differences between good and poor biofilm forming strains have not been studied. MATERIALS AND METHODS Biofilm yield of 32 Helicobacter pylori strains (standard strain and 31 clinical strains) were determined by crystal-violet assay and grouped into poor, moderate an...

Understanding the molecular pathogenesis of Coxiella burnetii, the causative agent of human Q fever, has historically been hindered by the technical difficulties of genetically manipulating obligate intracellular bacteria. The recent development of culture conditions suitable for axenic propagation of C. burnetii has paved the way for the application of a range of genetic techniques to address ...