Anaphylatoxins: their role in bacterial infection and inflammation.

Activation of the complement system plays a crucial role in the pathogenesis of infection and inflammation. Especially the complement activation products C3a and C5a, known as the anaphylatoxins, are potent proinflammatory mediators. In addition to their evident role in innate immunity, it is clear that the anaphylatoxins also play a role in regulation of adaptive immune responses.

Increased detection of respiratory syncytial virus, influenza viruses, parainfluenza viruses, and adenoviruses with real-time PCR in samples from patients with respiratory symptoms.

Respiratory samples (n = 267) from hospitalized patients with respiratory symptoms were tested by real-time PCR, viral culture, and direct immunofluorescence for respiratory syncytial virus, influenza virus, parainfluenza viruses, and adenoviruses. Compared with conventional diagnostic tests, real-time PCR increased the diagnostic yields for these viruses from 24% to 43% and from 3.5% to 36% for children and adults, respectively.

Key reports from the XV International HIV Drug Resistance Workshop 2006.

The XV International HIV Drug Resistance Workshop recorded advances in basic and clinical science of HIV resistance to antiretrovirals as well as new findings on resistance by hepatitis B virus (HBV) and hepatitis C virus (HCV). In the clinical arena, attendees learned of four cases of resistance to lopinavir/ritonavir monotherapy, correlation between low-frequency pretreatment mutations and failure of a first antiretroviral regimen, emergence of non-nucleoside-related mutations in 20% of patients interrupting a suppressive nonnucleoside regimen, and evolution of mutations conferring resistance to an HIV entry inhibitor that is being studied as a vaginal microbicide. New data reported from the POWER 1, 2 and 3 salvage trials suggested that there is a close correlation between darunavir (TMC114) phenotypic susceptibility, the number of baseline protease inhibitor-related resistance mutations and virological response.

Rubella virus-associated uveitis in a nonvaccinated child.

Purpose: To report presumed Fuchs heterochromic uveitis (FHU) associated with Rubella virus (RV)-specific intraocular antibody production in a child who was not vaccinated against rubella.

Design: Observational case report.

Methods: We examined a 13-year-old boy with chronic anterior uveitis complicated by mature cataract.

HIV protease resistance and viral fitness.

Purpose Of Review: This review focuses on the evolution of protease inhibitor resistance and replication capacity in the presence and absence of protease inhibitor pressure.

Recent Findings: Classically, HIV escapes through mutations in the protease itself causing a decrease in affinity to the inhibitor, leading to resistance. These changes also affect the binding of the enzyme to the natural substrate, and as a consequence cause a decrease in replication capacity of the virus.

Failure to control an outbreak of qnrA1-positive multidrug-resistant Enterobacter cloacae infection despite adequate implementation of recommended infection control measures.

A large outbreak with an aminoglycoside-resistant Enterobacter cloacae (AREC) clone occurred at the University Medical Center Utrecht beginning in 2001 and continued up through the time that this study was completed. This clone (genotype I) contains a conjugative R plasmid carrying the qnrA1, bla(CTX-M-9), and aadB genes, encoding resistance to quinolones, extended-spectrum beta-lactamases, and aminoglycosides, respectively. The aim of this study was to determine whether this clone was more transmissible than other AREC strains.

A novel substrate-based HIV-1 protease inhibitor drug resistance mechanism.

Background: HIV protease inhibitor (PI) therapy results in the rapid selection of drug resistant viral variants harbouring one or two substitutions in the viral protease. To combat PI resistance development, two approaches have been developed. The first is to increase the level of PI in the plasma of the patient, and the second is to develop novel PI with high potency against the known PI-resistant HIV protease variants.

Persistence of HIV-1 variants with multiple protease inhibitor (PI)-resistance mutations in the absence of PI therapy can be explained by compensatory fixation.

Objective: To investigate the mechanism explaining the persistence of human immunodeficiency virus (HIV) type 1 variants with multiple protease inhibitor (PI)-resistance mutations in the absence of PI therapy.

Methods: Longitudinal genotypic analyses were performed on sequential samples obtained from 2 HIV-1-infected patients who had stopped PI therapy for 4 years. Replication capacity (RC) was determined using recombinant viruses.

Selective digestive tract decontamination--will it prevent infection with multidrug-resistant gram-negative pathogens but still be applicable in institutions where methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci are endemic?

The purposes of selective decontamination of the digestive tract are to treat infections that may be incubating at the time a patient is admitted to an intensive care unit (ICU), by intravenous administration of antibiotics during the first days of a stay in the ICU, and to prevent ICU-acquired infections, by topical application of antibiotics in the oropharynx and the gastrointestinal tract. Despite multiple trials in which a considerable reduction in the incidence of ventilator-associated pneumonia was demonstrated, major objections against the routine use of selective decontamination of the digestive tract have included a lack of demonstrated reductions in mortality rates and in length of stay (in individual trials), a lack of cost-efficacy data, and the threat of selection of multidrug-resistant bacteria. Recently, 2 controlled, randomized studies reported significant reductions in mortality rates among patients in ICUs who underwent selective decontamination of the digestive tract in combination with reduced selection of antibiotic-resistant pathogens.

Longitudinal European surveillance study of antibiotic resistance of Haemophilus influenzae.

Objectives: We assessed the current resistance rates of Haemophilus influenzae against beta-lactams and other agents in Europe and compared the results with those of our previously performed surveillance study.

Methods: MICs of the antibiotics were determined using broth microdilution. The penicillin-binding domain of PBP3 of beta-lactamase (BL)-negative, amoxicillin-resistant (BLNAR) isolates was sequenced.

Early expression of SCIN and CHIPS drives instant immune evasion by Staphylococcus aureus.

Chemotaxis inhibitory protein of staphylococci (CHIPS) and Staphylococcal complement inhibitor (SCIN) are small, excreted molecules that play a crucial role in the staphylococcal defence against the human innate immune system. Here we show that they both counteract crucial acute responses of our immune system such as complement activation, neutrophil chemotaxis and neutrophil activation. By studying gene expression via promoter-green fluorescent protein fusions, Northern blots and protein expression analyses, we show that SCIN and CHIPS are produced during the early (exponential) growth stages.

Novel mobile variants of staphylococcal cassette chromosome mec in Staphylococcus aureus.

Staphylococcus aureus staphylococcal cassette chromosome mec type IV (SSCmec IV) is associated with virulent community-acquired methicillin-resistant Staphylococcus aureus (MRSA) and frequent horizontal transfer among staphylococci. To gain insight into the mechanism of transfer, we studied the ccrA/B type 2 recombinase-mediated excision of SCCmec IV (n = 5 strains) and SCCmec II (n = 2). In SCCmec IV- but not SCCmec II-containing strains, spontaneous excision of the cassette was observed.

An increase in viral replicative capacity drives the evolution of protease inhibitor-resistant human immunodeficiency virus type 1 in the absence of drugs.

Little is known about the factors which drive the evolution of protease inhibitor-resistant human immunodeficiency virus type-1 in the absence of drugs. To examine if viral replicative capacity (RC) is an important determinant, we performed in vitro evolution experiments in the absence of drugs with a unique panel of 6 drug-resistant human immunodeficiency virus type-1 recombinant protease variants with a range of different RC. The experiments revealed that an increase in viral RC was indeed an important determinant of evolution.

Priorities for antibiotic resistance surveillance in Europe.

Antibiotic resistance is an increasing global problem. Surveillance studies are needed to monitor resistance development, to guide local empirical therapy, and to implement timely and adequate countermeasures. To achieve this, surveillance studies must have standardised methodologies, be longitudinal, and cover a sufficiently large and representative population.

Polymerase chain reaction and Goldmann-Witmer coefficient analysis are complimentary for the diagnosis of infectious uveitis.

Purpose: To determine the relative contribution of the analysis of intraocular antibody production and the polymerase chain reaction (PCR) in aqueous humor (AH) to the diagnosis of infectious uveitis.

Design: Retrospective case-control study.

Methods: Paired AH and serum samples from 230 patients suspected of infectious uveitis were examined for intraocular antibody production against herpes simplex virus (HSV), varicella zoster virus (VZV), and Toxoplasma gondii by calculating the Goldmann-Witmer coefficient (GWC).

Rubella virus is associated with fuchs heterochromic iridocyclitis.

Purpose: To determine whether rubella virus (RV) is involved in the pathogenesis of Fuchs heterochromic iridocyclitis (FHI).

Design: Retrospective patient-controlled study.

Methods: Intraocular immunoglobulin G production against RV, herpes simplex virus (HSV), varicella zoster virus (VZV), and Toxoplasma gondii was determined in the aqueous humor of 14 patients with FHI, 13 control subjects with herpetic uveitis anterior, and 19 control subjects with ocular toxoplasmosis by calculation of the Goldmann-Witmer coefficient (GWC).

Endothelial activation and induction of monocyte adhesion by nontransferrin-bound iron present in human sera.

Nontransferrin-bound iron (NTBI) has been detected in iron overload diseases. This form of iron may exert pro-oxidant effects and modulate cellular function and inflammatory response. The present study has aimed to investigate the effects of serum NTBI on monocyte adherence to endothelium.

Bleomycin has antiviral properties against drug-resistant HIV strains and sensitises virus to currently used antiviral agents.

In this study we performed phenotypic assays to assess involvement of the cancer chemotherapeutic agent bleomycin (BLM) in replication inhibition of mutant HIV-1 viral strains. Three clinically relevant mutant HIV variants, including one containing the Q151M mutation conferring multinucleoside resistance, were equally as sensitive to BLM as the wild-type HXB2 strain. Long-term incubation of BLM with a wild-type HIV(Ba-L) strain did not alter the sensitivity of the strain to BLM (IC(50) of BLM 0.

Surveillance uncovers the smoking gun for resistance emergence.

Today, antibiotic resistance is becoming a major healthcare concern. As global travel increases, more antibiotic-resistant bacteria will be disseminated from one country to another, thereby imposing a problem worldwide. Since the development of resistance is an evolutionary process, constant surveillance is needed to gain insight into the problem and surveillance studies needed to document the spread of antibiotic resistance.

Susceptibility of European beta-lactamase-positive and -negative Haemophilus influenzae isolates from the periods 1997/1998 and 2002/2003.

Aims: To test prospectively the activity of cefixime and comparators against Haemophilus influenzae from Europe and to compare the susceptibilities of isolates from 1997/1998 with isolates from 2002/2003 paying special attention to the epidemiology of amoxicillin resistance.

Methods: MICs of antibiotics were determined using broth microdilution. For beta-lactamase-negative isolates with reduced susceptibility to amoxicillin, the nucleotide sequence of the penicillin-binding domain of PBP3 was determined.

Spectrum of antiviral activity of o-(acetoxyphenyl)hept-2-ynyl sulphide (APHS).

Since some antiviral drugs have a broad spectrum of action, the aim of this study was to assess whether o-(acetoxyphenyl)hept-2-ynyl sulphide (APHS), a recently described inhibitor of human immunodeficiency virus type 1 (HIV-1) replication, has an effect on the replication of other retroviruses, (-) and (+) RNA viruses and DNA viruses. APHS did not affect the replication of feline immunodeficiency virus, HIV-2 and a HIV-1 strain resistant to non-nucleoside reverse transcriptase inhibitors (NNRTI). APHS could also not inhibit the replication of the RNA viruses, respiratory syncytium virus or mouse hepatitis virus.

Anti-HIV drug development--an overview.

Highly active antiretroviral therapy (HAART) has markedly decreased mortality and morbidity in the developed world. HAART consists of a combination of three or more of the following classes of antiretroviral (ARV) drug: reverse transcriptase inhibitors, protease inhibitors and a recently approved fusion inhibitor. However, HAART cannot completely eradicate HIV from the body, results in long-term toxicity and eventually leads to the emergence of drug-resistant HIV strains.

Intracellular labile iron modulates adhesion of human monocytes to human endothelial cells.

Objective: Elevated iron stores and high plasma iron concentration have been linked to an increased risk of atherosclerosis. Iron may thereby affect the interaction of monocytes to endothelium, an initial event in the formation of atherosclerotic plaques.

Methods And Results: Addition of 10 mumol/L non-transferrin-bound iron to the incubation medium caused a 2-fold increase in monocyte adhesion to human umbilical vein endothelial cells (HUVECs).

Mechanism of inhibition of the human immunodeficiency virus type 1 by the oxygen radical generating agent bleomycin.

Alternative targets of attack of the human immunodeficiency virus (HIV) are necessary in light of infection persistence due to onset of resistance after conventional reverse transcriptase and protease inhibitor therapy. We have recently shown that the cancer chemotherapeutic agent bleomycin (BLM) dose-dependently inhibits HIV-1 replication. The mechanism of this viral inhibition in vitro was investigated.