Characterising variation in five genetic loci of cytomegalovirus during treatment for congenital infection.

Cytomegalovirus (CMV) is the most common congenital infection in humans and a leading cause of sensorineural hearing loss. Ganciclovir (6 mg/kg twice daily for 42 days) has been shown to reduce hearing deterioration and is used in clinical practice. Vaccines and passive administration of antibody are being evaluated in randomized controlled trials in allograft candidates, women of childbearing age, and pregnant women with primary CMV infection.

HIV co-receptor tropism prediction remains stable over time in treatment-naïve patients.

HIV co-receptor tropism determination is essential before prescribing the CCR5 antagonist maraviroc. British HIV Association guidelines suggest tropism testing may remain valid for only 90 days in antiretroviral-naïve patients. We aimed to determine the accuracy of this figure.

The role of CXC chemokine receptor 2 in Staphylococcus aureus keratitis.

Staphylococcus aureus is a leading cause of corneal infection. CXC receptor 2 binding chemokines have been implicated in the pathogenesis of Pseudomonas aeruginosa keratitis. The role of this receptor in immune responses during Staphylococcus keratitis remains to be fully understood.

Interleukin 28B gene polymorphisms and Epstein-Barr virus-associated lymphoproliferative diseases.

Objectives: Single-nucleotide polymorphisms (SNPs) near the interleukin (IL) 28B gene encoding a type III interferon (IFN-λ) are the most important genetic predictors of treatment response to hepatitis C virus (HCV). This retrospective study was undertaken to determine any association between IL28B SNPs and the development of viraemia in Epstein-Barr virus (EBV)-driven acute infectious mononucleosis (IM) and post-transplant lymphoproliferative disease (PTLD).

Methods: Genomic DNA extracted from plasma from 45 EBV seropositive controls and 46 acute IM, 23 non-PTLD (transplant) and 21 PTLD patients was tested by PCR for 2 SNPs within IL28B.

Sensitive testing of plasma HIV-1 RNA and Sanger sequencing of cellular HIV-1 DNA for the detection of drug resistance prior to starting first-line antiretroviral therapy with etravirine or efavirenz.

Objectives: This study investigated strategies that may increase the yield of drug resistance testing prior to starting antiretroviral therapy (ART), and whether transmitted and polymorphic resistance-associated mutations (RAMs) correlated with virological outcomes.

Methods: We carried out retrospective testing of baseline samples from patients entering the SENSE trial of first-line ART in Europe, Russia and Israel. Prior to randomization to etravirine or efavirenz plus two nucleos(t)ide reverse transcriptase inhibitors (NRTIs), plasma samples underwent routine Sanger sequencing of HIV-1 RT and protease ((plasma)SS) in order to exclude patients with transmitted RAMs.

Can Simpson's paradox explain co-operation in Pseudomonas aeruginosa biofilms?

Co-operative behaviours, such as the production of public goods, are commonly displayed by bacteria in biofilms and can enhance their ability to survive in environmental or clinical settings. Non-co-operative cheats commonly arise and should, theoretically, disrupt co-operative behaviour. Its stability therefore requires explanation, but no mechanisms to suppress cheating within biofilms have yet been demonstrated experimentally.

Characterization of protease IV expression in Pseudomonas aeruginosa clinical isolates.

Expression of protease IV by Pseudomonas aeruginosa during ocular infections contributes significantly to tissue damage. However, several P. aeruginosa strains isolated from ocular infections or inflammatory events produce very low levels of protease IV.

Role of mutation in Pseudomonas aeruginosa biofilm development.

The survival of bacteria in nature is greatly enhanced by their ability to grow within surface-associated communities called biofilms. Commonly, biofilms generate proliferations of bacterial cells, called microcolonies, which are highly recalcitrant, 3-dimensional foci of bacterial growth. Microcolony growth is initiated by only a subpopulation of bacteria within biofilms, but processes responsible for this differentiation remain poorly understood.

Pseudomonas aeruginosa quorum-sensing signal molecules induce IL-8 production by human corneal epithelial cells.

Objectives: The aim of the present study was to evaluate whether the quorum-sensing molecules of Pseudomonas aeruginosa could induce the production of interleukin-8 (IL-8) in human corneal epithelial (HCE) cells in vitro.

Methods: A confluent monolayer of immortalized HCE cells was treated with 12.5 to 50 microM n-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) or n-butanoyl-L-homoserine lactone (BHL) for 18 hours, or challenged with a wild-type P.

Phenotypic characterization of clonal and nonclonal Pseudomonas aeruginosa strains isolated from lungs of adults with cystic fibrosis.

The emergence of virulent Pseudomonas aeruginosa clones is a threat to cystic fibrosis (CF) patients globally. Characterization of clonal P. aeruginosa strains is critical for an understanding of its clinical impact and developing strategies to meet this problem.

Protease IV production in Pseudomonas aeruginosa from the lungs of adults with cystic fibrosis.

Protease IV is important in the pathogenesis of Pseudomonas aeruginosa-induced microbial keratitis, but little is known of its role in cystic fibrosis (CF) lung infection. In this study protease IV production was examined in 43 P. aeruginosa isolates (24 non-clonal and 19 clonal) from the lungs of chronically infected adult patients attending the Royal Prince Alfred Hospital CF Clinic, Sydney, Australia.

Type III secretion system-associated toxins, proteases, serotypes, and antibiotic resistance of Pseudomonas aeruginosa isolates associated with keratitis.

The association between possession of toxin gene-related type III secretory system, protease profiles, O serotypes, and antibiotic resistance patterns was characterized genetically and phenotypically in 46 keratitis isolates of Pseudomonas aeruginosa. There was no significant difference in exoU or exoS prevalence among the keratitis strains. Distinct protease profiles were seen in isolates harboring either exoU or exoS genes.

Pseudomonas aeruginosa with lasI quorum-sensing deficiency during corneal infection.

Purpose: To understand the importance of Pseudomonas aeruginosa quorum-sensing systems in the development of corneal infection, the genotypic characteristics and pathogenesis of seven ocular isolates with low-protease and acyl homoserine lactone (AHL) activity and quorum-sensing mutants of PAO1 deficient in lasI, lasR, or rhlR were investigated in the study.

Methods: The possession of the quorum-sensing genes lasI, lasR, rhlI, rhlR, and the quorum-sensing controlled genes lasB, aprA, and rhlAB in the clinical isolates were determined by polymerase chain reaction and Southern blot hybridization. Elastinolytic activity, controlled by the las system, was assayed using elastin Congo red and rhamnolipid production controlled by the rhl system was assessed using agar plates containing methylene blue/cetyltrimethyl ammonium bromide.