Invasive sinonasal disease due to Scopulariopsis candida: case report and review of scopulariopsosis.

Journal ArticleSinonasal infection with fungi of the order Mucorales--termed mucormycosis or zygomycosis--is sometimes seen in immunosuppressed patients, including those with diabetic ketoacidosis and malignancy. We describe a case of invasive sinonasal infection with Scopulariopsis candida (not among the Mucorales organisms) in a 12-year-old girl who was being treated for non-Hodgkin's lymphoma. Only a few cases of invasive infection with Scopulariopsis species have been reported previously; five of six of these cases were associated with persistent or fatal disease. Our patient survived without undergoing radical surgical debridement and was treated with granulocyte colony-stimulating factor, amphotericin B, and itraconazole; chemotherapy was stopped. In vitro susceptibility testing of our patient's Scopulariopsis isolate showed that it was resistant to amphotericin B and that it was relatively susceptible to itraconazole and miconazole. The case described herein demonstrates the expanding spectrum of fungal organisms that may cause invasive sinonasal infection in immunocompromised hosts and the need for reliable antifungal susceptibility testing

Cytotoxic mAb from Rheumatic Carditis Recognizes Heart Valves and Laminin

Anti-streptococcal antibodies cross-reactive with N-acetyl-bD-glucosamine (GlcNAc) and myosin are present in the sera of patients with rheumatic fever (RF). However, their role in tissue injury is not clear. In this study, we show that anti-GlcNAc/anti-myosin mAb 3.B6 from a rheumatic carditis patient was cytotoxic for human endothelial cell lines and reacted with human valvular endothelium and underlying basement membrane. Reactivity of mAb 3.B6 with the valve was inhibited by human cardiac myosin \u3e laminin \u3e GlcNAc. The mAb 3.B6 epitopes were localized in fragments of human cardiac myosin, including heavy meromyosin (HMM), the S1 subfragment, and two light meromyosin (LMM) peptides containing amino acid sequences KEALISSLTRGKLTYTQQ (LMM 1) and SERVQLLHSQNTSLINQK (LMM 33). A novel feature of mAb 3.B6 was its reactivity with the extracellular matrix protein laminin, which may explain its reactivity with the valve surface. A laminin A-chain peptide (HTQNT) that includes homology to LMM33 inhibited the reactivity of mAb 3.B6 with human valve. These data support the hypothesis that cross-reactive antibodies in rheumatic carditis cause injury at the endothelium and underlying matrix of the valve

Serotype III Streptococcus agalactiae from Bovine Milk and Human Neonatal Infections1

Although largely unrelated, many bovine type III GBS appear to share a common ancestor with an important human clone

Regulation of apoptosis by gram-positive bacteria: Mechanistic diversity and consequences for immunity

Apoptosis, or programmed cell death (PCD), is an important physiological mechanism, through which the human immune system regulates homeostasis and responds to diverse forms of cellular damage. PCD may also be involved in immune counteraction to microbial infection. Over the past decade, the amount of research on bacteria-induced PCD has grown tremendously, and the implications of this mechanism on immunity are being elucidated. Some pathogenic bacteria actively trigger the suicide response in critical lineages of leukocytes that orchestrate both the innate and adaptive immune responses; other bacteria proactively prevent PCD to benefit their own survival and persistence. Currently, the microbial virulence factors, which represent the keys to unlocking the suicide response in host cells, are a primary focus of this field. In this review, we discuss these bacterial "apoptosis regulatory molecules" and the apoptotic events they either trigger or prevent, the host target cells of this regulatory activity, and the possible ramifications for immunity to infection. Gram-positive pathogens including Staphylococcus, Streptococcus, Bacillus, Listeria, and Clostridia species are discussed as important agents of human infection that modulate PCD pathways in eukaryotic cells

Nitric oxide is a key determinant of group B streptococcus-induced murine macrophage apoptosis

Group B streptococcus (GBS; Streptococcus agalactiae) induces apoptosis of macrophages, and this may be an important mechanism GBS uses to suppress immune responses. The mechanisms whereby GBS induces apoptosis have not been identified. We studied GBS infection in murine macrophage - like J774A.1 cells and analyzed gene expression before apoptosis. Tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and inducible nitric oxide synthase ( iNOS) gene expression coincided with apoptosis. Inhibition of iNOS gene expression by use of N-G-monomethyl-L-arginine ( NMMA) inhibited apoptosis, whereas inhibition of TNF-alpha and IL-1 biological activity did not. Macrophages from congenic iNOS-deficient mice were less susceptible to apoptosis than were macrophages from C57BL/6 mice. The NO donor S-nitroso-N-acetylpenicillamine ( SNAP) induced apoptosis without infection, confirming its proapoptotic effect. NMMA did not impair the microbicidal activity of macrophages, however, and SNAP was not bactericidal against GBS in vitro. In human monocyte - derived macrophages (HMDMs), NO production was minimal, even after costimulation with IFN-gamma and lipopolysaccharide. Dose-dependent apoptosis of HMDMs occurred without a significant NO response. Thus, NO is an important mediator of GBS-induced murine macrophage apoptosis but does not contribute to antimicrobial activity or cytotoxicity in HMDMs. HMDMs and murine macrophages are killed by GBS by alternative, NO-independent mechanisms. Future studies of host-cell machinery commandeered by GBS to bring about apoptosis will be important for understanding the role played by apoptosis in defense against this important human pathogen

Nontypeable Haemophilus influenzae Adheres to Intercellular Adhesion Molecule 1 (ICAM-1) on Respiratory Epithelial Cells and Upregulates ICAM-1 Expression

Nontypeable Haemophilus influenzae (NTHI) is an important respiratory pathogen. NTHI initiates infection by adhering to the airway epithelium. Here, we report that NTHI interacts with intracellular adhesion molecule 1 (ICAM-1) expressed by respiratory epithelial cells. A fourfold-higher number of NTHI bacteria adhered to Chinese hamster ovary (CHO) cells transfected with human ICAM-1 (CHO-ICAM-1) than to control CHO cells (P ≤ 0.005). Blocking cell surface ICAM-1 with specific antibody reduced the adhesion of NTHI to A549 respiratory epithelial cells by 37% (P = 0.001) and to CHO-ICAM-1 cells by 69% (P = 0.005). Preincubating the bacteria with recombinant ICAM-1 reduced adhesion by 69% (P = 0.003). The adherence to CHO-ICAM-1 cells of NTHI strains deficient in the adhesins P5, P2, HMW1/2, and Hap or expressing a truncated lipooligosaccharide was compared to that of parental strains. Only strain 1128f(−), which lacks the outer membrane protein (OMP) P5-homologous adhesin (P5 fimbriae), adhered less well than its parental strain. The numbers of NTHI cells adhering to CHO-ICAM-1 cells were reduced by 67% (P = 0.009) following preincubation with anti-P5 antisera. Furthermore, recombinant ICAM bound to an OMP preparation from strain 1128f(+), which expresses P5, but not to that from its P5-deficient mutant, confirming a specific interaction between ICAM-1 and P5 fimbriae. Incubation of respiratory epithelial cells with NTHI increased ICAM-1 expression fourfold (P = 0.001). Adhesion of NTHI to the respiratory epithelium, therefore, upregulates the expression of its own receptor. Blocking interactions between NTHI P5 fimbriae and ICAM-1 may reduce respiratory colonization by NTHI and limit the frequency and severity of NTHI infection