Routine use of a highly automated and internally controlled real-time PCR assay for the diagnosis of herpes simplex and varicella-zoster virus infections.

Background: Detection of herpes viruses can be significantly improved by PCR. The development of real-time PCR, which has overcome several limitations of conventional PCR, improved the prospects for implementation of PCR-based assays in diagnostic laboratory.

Objectives: To compare the diagnostic performance of an automated sample extraction procedure in combination with an internally controlled real-time PCR assay for detection of herpes simplex virus (HSV) and varicella-zoster virus (VZV) to conventional shell vial culture.

Resistance integrons and super-integrons.

Integrons are genetic elements composed of a gene encoding an integrase, gene cassettes and an integration site for the gene cassettes (att). The integrase excises and integrates the gene cassettes from and into the integron, but integrons themselves are not mobile. Two groups of integrons are known: resistance integrons and super-integrons.

Sequential switching of DNA polymerase and thymidine kinase-mediated HSV-1 drug resistance in an immunocompromised child.

Sequential herpes simplex virus type 1 (HSV-1) isolates were obtained from a paediatric haematopoietic stem cell transplant (HSCT) patient who received prolonged therapy with acyclovir (ACV) followed by foscarnet (PFA) and topical cidofovir (HPMPC) for severe persistent mucocutaneous HSV-1 infection. The isolates were retrospectively studied for drug resistance. The first resistant isolate associated with clinical failure of antiviral therapy emerged 44 days post-ACV treatment initiation.

False-positive results and contamination in nucleic acid amplification assays: suggestions for a prevent and destroy strategy.

Contamination of samples with DNA is still a major problem in microbiology laboratories, despite the wide acceptance of PCR and other amplification techniques for the detection of frequently low amounts of target DNA. This review focuses on the implications of contamination in the diagnosis and research of infectious diseases, possible sources of contaminants, strategies for prevention and destruction, and quality control. Contamination of samples in diagnostic PCR can have far-reaching consequences for patients, as illustrated by several examples in this review.

Identification of a new geographically widespread multiresistant Acinetobacter baumannii clone from European hospitals.

The aim of the study was to investigate the genetic diversity of Acinetobacter baumannii clinical strains that had previously been allocated to three major groups based on automated ribotyping. Forty-seven isolates from European hospitals and one isolate from a South African hospital, geographically representative of the three ribogroups (ribogroups 1, 2 and 3 with 10, 23 and 15 isolates, respectively), were analysed using the highly discriminatory fingerprinting methods AFLP and pulsed-field gel electrophoresis (PFGE). Based on AFLP data, the isolates clustered into three main groups, each corresponding to one ribogroup.

Multiple effects of HIV-1 trans-activator protein on the pathogenesis of HIV-1 infection.

The HIV-1 trans-activator (Tat) protein is proposed as an important factor in the complex HIV-induced pathogenesis of AIDS. In this paper, multiple effects of this viral protein are described. Originally discovered as an intracellular activator of HIV-1 transcription, Tat was found to regulate viral reverse transcription as well.

Worldwide transmission of drug-resistant HIV.

The availability of highly active antiretroviral therapy (HAART), that suppresses replication of the human immunodeficiency virus type 1 (HIV-1), has dramatically improved the prognosis of HIV-infected patients. In populations with access to HAART, the course of the infection has changed from an inevitably fatal disease, characterized by a high incidence of opportunistic infections, into a potentially-treatable chronic condition. Unfortunately, HAART does not durably suppress HIV replication in 20-50% of treatment-naive patients and in up to 50-70% of treatment-experienced patients.

High levels of hydrolytic enzymes secreted by Candida albicans isolates involved in respiratory infections.

Differences in production of two putative virulence factors of Candida albicans, phospholipase and proteinase, were determined for a large panel of clinical C. albicans isolates (n = 186) obtained from the European SENTRY programme. Seventy-two per cent of isolates produced detectable amounts of phospholipase and 95 % of isolates produced detectable amounts of proteinase.

Aspirin-like molecules that inhibit human immunodeficiency virus 1 replication.

Some anti-inflammatory molecules are also known to possess anti-human immunodeficiency virus (HIV) activity. We found that o-(acetoxyphenyl)hept-2-ynyl sulfide (APHS), a recently synthesized non-steroidal anti-inflammatory molecule can inhibit HIV-1 replication. The aim of this study was to clarify the mechanism of action of APHS.

Differential microorganism-induced mannose-binding lectin activation.

Mannose-binding lectin (MBL) is a serum complement factor playing a dominant role in first-line defense. When MBL binds to specific sugar moieties on microorganisms, the lectin complement pathway (LCP) is activated. Changes in the mbl gene and promotor may result in MBL with less activity, predisposing the individual to recurrent infections.

Use of amplified fragment length polymorphism analysis to identify medically important Candida spp., including C. dubliniensis.

Non-Candida albicans Candida species are increasingly being isolated. These species show differences in levels of resistance to antimycotic agents and mortality. Therefore, it is important to be able to correctly identify the causative organism to the species level.

APHS can act synergically with clinically available HIV-1 reverse transcriptase and protease inhibitors and is active against several drug-resistant HIV-1 strains in vitro.

Objectives: The use of multiple drug combinations in current anti-human immunodeficiency virus (HIV) therapy allows lower dosages of individual drugs and results in enhancement of the therapeutic effect due to synergic interactions between different drugs. We have shown that o-(acetoxyphenyl)hept-2-ynyl sulphide (APHS), a recently developed non-steroidal anti-inflammatory drug, shows anti-HIV activity in a dose-dependent manner. The first aim of this study was to investigate whether APHS can act synergically with the clinically available reverse transcriptase and protease inhibitors (RTIs and PIs, respectively) in vitro.

Clinical evaluation of a NASBA-based assay for detection of Candida spp. in blood and blood cultures.

The number of life-threatening opportunistic fungal infections has shown a dramatic increase. However, the diagnosis of candidemia remains difficult. Nucleic acid amplification assays may improve the detection rate and decrease the time needed for detection and identification of Candida spp.

Rapid and sensitive routine detection of all members of the genus enterovirus in different clinical specimens by real-time PCR.

We developed a rapid and sensitive method for the routine detection of all members of the enterovirus genus in different clinical specimens by using real-time TaqMan quantitative PCR. Multiple primer and probe sets were selected in the highly conserved 5'-untranslated region of the enterovirus genome. Our assay detected all 60 different enterovirus species tested, whereas no reactivity was observed with the viruses from the other genera of the picornaviridae family, e.

A hemolytic assay for the estimation of functional mannose-binding lectin levels in human serum.

A simple assay was developed to estimate functional mannose-binding lectin (MBL) levels in serum based on the principle of yeast-induced bystander lysis of chicken erythrocytes (ChE). The assay is sensitive to inhibition by ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) (which allows alternative pathway activation), ethylene diamine tetraacetic acid (EDTA), mannose, N-acetylglucosamine and C1 esterase inhibitor (C1-INH), whereas it was not inhibited by galactose. A high-titer human anti-mannan antibody-containing serum with 0.

Application of real-time PCR for determination of antiviral drug susceptibility of herpes simplex virus.

A quantitative real-time PCR (TaqMan) assay was developed for determination of antiviral drug susceptibility of herpes simplex virus (HSV). After short-time culture of the virus, the antiviral drug susceptibility of HSV isolates for acyclovir (ACV) was determined by measuring the reduction of the HSV type 1 (HSV-1) DNA levels in culture supernatants using real-time PCR. The 50% inhibitory concentration was reported as the concentration of antiviral drug that reduced the number of HSV-1 DNA copies by 50%.

In vitro activity of AZD2563, a novel oxazolidinone, against European Gram-positive cocci.

AZD2563 is a new oxazolidinone that has targeted activity against Gram-positive bacteria. The in vitro activity of AZD2563 and nine comparators against 1543 European enterococcal, staphylococcal and streptococcal isolates was determined. The compound is a potent oxazolidinone, with no isolate tested displaying an MIC > 4 mg/L and 94.