CD66b Overexpression and Loss of C5a Receptors as Surface Markers for Staphylococcus aureus-Induced Neutrophil Dysfunction.

Neutrophil granulocytes constitute the main component of innate immunity in the clearance of bacterial infections. However, during systemic inflammation, immunoparalysis may occur resulting in neutrophil dysfunction. This study presents a new in vitro model for analyzing the dysfunction of human peripheral blood neutrophils resulting from the interaction with Staphylococcus aureus components in whole blood.

Negative impact of linezolid on human neutrophil functions in vitro.

Background/aims: In a recent phase III clinical trial on linezolid, more patients in the linezolid treatment arm acquired Gram-negative catheter-related bloodstream infections despite the adequate therapy of infections caused by Gram-negative bacteria. We tested our hypothesis that linezolid impairs phagocytosis and the killing of Gram-negative bacteria by polymorphonuclear leukocytes (PMN).

Methods: The influence of clinically relevant concentrations (5, 20 and 50 mg/l) of linezolid on granulocyte function in vitro was tested.

Phenotyping of Staphylococcus aureus reveals a new virulent ST398 lineage.

Staphylococcus aureus sequence type (ST)398, which is commonly found as a colonization strain in pig farming, is emerging more frequently as the cause of human infections. In this study, we analysed ST398 of porcine and human origin at the genetic, protein and immunogenic levels. Although genetic analysis of the genes encoding the major virulence factors revealed the presence of the same genes in all strains studied, the results demonstrated spa type crossing alterations in adhesion abilities in addition to a strongly enhanced lysis activity directly linked to impaired clearance attributable to polymorphonuclear leukocytes (PMNs).

CD66b overexpression and homotypic aggregation of human peripheral blood neutrophils after activation by a gram-positive stimulus.

Neutrophils represent the main component of innate immunity in the clearance of bacterial infections. To pass the tissue and to localize and reach the site of infection, the peripheral blood neutrophils have to pass through a complex receptor-mediated interaction with the endothelial layer. Under pathophysiological conditions, such as severe sepsis, this process is impaired and often characterized by neutrophil aggregation.

Garenoxacin-induced increase of CD11b expression on human polymorphonuclear neutrophils does not affect phagocytosis and killing of Staphylococcus aureus.

Garenoxacin is considered to be the most active quinolone against Staphylococcus aureus. Quinolones are believed to alter the function of human polymorphonuclear leukocytes (PMN) and garenoxacin is known to be the only quinolone which alters the expression of the beta-chain (CD11b) of the complement receptor 3 (CR3) which is known to be important in the phagocytosis of S. aureus by PMN.

Influence of fluoroquinolones on phagocytosis and killing of Candida albicans by human polymorphonuclear neutrophils.

Candida albicans infections often occur during or shortly after antibacterial treatment. Phagocytosis by polymorphonuclear neutrophil granulocytes (PMN) is the most important primarily defence mechanism against C. albicans.

Isolation of fungi, especially Exophiala dermatitidis, in patients suffering from cystic fibrosis. A prospective study.

Background: Patients with cystic fibrosis (CF) are at an increased risk of pulmonary colonisation by opportunistic micro-organisms. Using specialised methods, the black yeast Exophiala dermatitidis could consistently be cultured from CF patients. Isolation rates from sputum samples ranged between 1.

Analyses of phagocytosis, evoked oxidative burst, and killing of black yeasts by human neutrophils: a tool for estimating their pathogenicity?

The pathogenicity of several dematiaceous yeasts that have, to date, rarely been isolated in humans remains unclear. Because professional phagocytes are prominent in lesions caused by dematiaceous fungi, we address this issue by comparing phagocytosis, evoked oxidative burst and killing by human neutrophils of different black yeasts in vitro. Whereas phagocytosis of all black yeasts tested and evoked oxidative burst yielded comparable results, in contrast, the degree of killing differed significantly after 5 h.

Granulocyte colony-stimulating factor for the treatment of biomaterial-associated staphylococcal infections in-vitro.

Staphylococcal infections are a common and severe complication after the implantation of a prosthesis. We developed an in-vitro model for biomaterial-associated infections and studied the effects of human recombinant granulocyte colony-stimulating factor (rhuG-CSF; filgrastime) on the eradication of bacteria from the surface of biomaterial. Latex beads (25 micro m) were incubated with 10(7) colony forming units of either a slime producing (DSM 3269) or non-slime producing strain (ATCC 14990) of Staphylococcus epidermidis.

[Not Available].

The decrease in infectious diseases preventable by immunisation and the absence of complications caused by these diseases leads to an increased awareness of vaccine-associated adverse events. The analysis of a survey of the vaccine injury compensation data from the German Bundesländer shows the decrease in accepted and demanded compensation from 1991 to 1999. From 1976 to 1990 1139 of 4569 demands were accepted, whereas from 1991 to 1999, acceptance of only 389 of 2543 demands was reported.

M(+) group a streptococci are phagocytized and killed in whole blood by C5a-activated polymorphonuclear leukocytes.

Historically, resistance to phagocytosis has been determined by incubating group A streptococci in human blood and comparing the numbers of CFU before and after incubation. Utilizing a flow cytometry-based technique, we have investigated the phagocytosis of M(+) group A streptococci by polymorphonuclear leukocytes (PMNs) in heparinized human peripheral whole blood. Intracellular labeling of streptococci with a nontoxic fluorescent dye allowed us to quantify the association and phagocytosis of M(+) streptococci by PMNs in whole blood in the presence or absence of C5a, a physiologically important chemotactic activator of PMNs.

Simultaneous measurement of biopolymer-mediated Mac-1 up-regulation and adherence of neutrophils: a novel flow cytometric approach for predicting initial inflammatory interaction with foreign materials.

Implantation of any medical device normally causes an inflammatory cell interaction with the foreign material. In vitro cell activation of human neutrophils (Mac-1 upregulation) has been taken as one measure to assess the attributable risk of inflammation due to biopolymers before their clinical application. Mac-1 expression has generally been measured by flow cytometric assays, whereas quantification of neutrophil adhesion to the biopolymer surfaces has been performed by separate and time-consuming assays, e.

Phagocytosis, oxidative burst, and killing of Candida dubliniensis and Candida albicans by human neutrophils.

Candida dubliniensis is a phylogenetically closely related species to Candida albicans. So far virtually nothing is known about the virulence factors of C. dubliniensis.

Characterization of blood culture isolates of Streptococcus dysgalactiae subsp. equisimilis possessing Lancefield's group A antigen.

For three human blood culture isolates of beta-hemolytic streptococci with Lancefield's serogroup A antigen, phylogenetic analysis of the 16S rRNA genes confirmed biochemical identification as Streptococcus dysgalactiae subsp. equisimilis. Genes encoding M or M-like proteins, which are considered to be major virulence determinants in streptococci, were detected in all of these strains.

Successful treatment of pulmonary Mycobacterium xenopi infection in a natural killer cell-deficient patient with clarithromycin, rifabutin, and sparfloxacin.

Isolation of Mycobacterium xenopi from the respiratory tract may indicate pneumonia, often clinically indistinguishable from tuberculosis. Resistance to the classic antituberculous drugs renders the treatment of these infections problematic. We report on a case of cavernous pneumonia caused by M.

Flow cytometry to monitor phagocytosis and oxidative burst of anaerobic periodontopathogenic bacteria by human polymorphonuclear leukocytes.

The reduced susceptibility to phagocytosis found among some periodontopathogenic anaerobes may account for the differences between invasive and non-invasive strains. We applied flow cytometry as a powerful tool to analyze and quantify phagocytosis using standardized cultures of oral anaerobes (Porphyromonas gingivalis, Prevotella intermedia, P. nigrescens, Capnocytophaga gingivalis, C.

A co-stimulatory signal through ICAM-beta2 integrin-binding potentiates neutrophil phagocytosis.

The beta2 integrin LFA-1 (lymphocyte function associated antigen; CD11a/CD18) is the common ligand for the intercellular adhesion molecules (ICAMs). Integrins support cell function by providing co-stimulatory second signals that are a precondition for full cell activation first described for ICAM-1-binding to LFA-1 in lymphocytes. Integrins can also serve to activate functions associated with distinct subunits of other integrins.

Lmb, a protein with similarities to the LraI adhesin family, mediates attachment of Streptococcus agalactiae to human laminin.

Streptococcus agalactiae is a leading cause of neonatal sepsis and meningitis. Adherence to extracellular matrix proteins is considered an important factor in the pathogenesis of infection, but the genetic determinants of this process remain largely unknown. We identified and sequenced a gene which codes for a putative lipoprotein that exhibits significant homology to the streptococcal LraI protein family.

Effect of melanin and carotenoids of Exophiala (Wangiella) dermatitidis on phagocytosis, oxidative burst, and killing by human neutrophils.

The black yeast Exophiala (Wangiella) dermatitidis is an increasingly recognized pathogen and a leading cause of severe pheohyphomycosis. Melanin is thought to contribute to the virulence of E. dermatitidis.

Rapid identification of Candida glabrata by using a dipstick to detect trehalase-generated glucose.

Candida glabrata is a yeast frequently isolated from human specimens. Based upon its well-known ability to rapidly hydrolyze trehalose, we have developed a novel and cost-effective test incubating one yeast colony emulsified in 50 microl of citrate buffer (0.1 M [pH 5.

Impact of M49, Mrp, Enn, and C5a peptidase proteins on colonization of the mouse oral mucosa by Streptococcus pyogenes.

Resistance to phagocytosis is a hallmark of virulent Streptococcus pyogenes (group A streptococcus). Surface-bound C5a peptidase reduces recruitment of phagocytes to the site of infection, and hyaluronic acid capsules and/or the M protein limit the uptake of streptococci. In this study the relative impact of M and M-like proteins and the C5a peptidase on the virulence of a serotype M49 strain was assessed.

The rationale and method for constructing internal control DNA used in pertussis polymerase chain reaction.

The inclusion of an appropriate internal control DNA in polymerase chain reaction (PCR) is a rapid and simple method for the detection of PCR failure. Two PCR coamplification internal control DNAs (ICD I and ICD II) with the same primer-binding sequences as the target DNA for the detection of Bordetella pertussis and Bordetella parapertussis were produced using an overlap extension technique and a PCR MIMIC construction kit, respectively. The ICD II was further evaluated in a prospective clinical study in 360 patients with a clinical diagnosis of pertussis.

Discrimination of Bordetella parapertussis and Bordetella pertussis organisms from clinical isolates by PCR using biotin-labelled oligonucleotide probes.

A recently developed shared-primer polymerase chain reaction (PCR) was investigated, in an ongoing pertussis surveillance study for discrimination of Bordetella parapertussis and Bordetella pertussis organisms, by using specific biotin-labelled oligonucleotide probes. From a total of 132 samples, 83 were positive by the B. parapertussis specific probe, 33 were positive by the B.

Neisseria meningitidis serogroup B peritonitis associated with continuous ambulatory peritoneal dialysis.

A case of Neisseria meningitidis peritonitis in a 41-year-old female undergoing continuous ambulatory peritoneal dialysis for end-stage renal failure due to insulin-dependent diabetes mellitus is reported. The bacterial strain was serosubtyped as 4:P1.15, a rarely encountered type.

Remission of IgA nephropathy following treatment of cytomegalovirus infection with ganciclovir.

Following the detection of cytomegalovirus antigen in mesangial cells of some patients with IgA nephropathy, an important role of human cytomegalovirus in the pathogenesis of IgA nephropathy has been discussed. We studied a case of IgA nephropathy with rapid deterioration of renal function associated with cytomegalovirus infection. Following an infection of the upper respiratory tract, a 57-year-old woman developed with hematuria and acute renal failure.