Microbiological diagnosis and molecular typing of Legionella strains during an outbreak of legionellosis in Southern Germany.

An explosive outbreak of Legionnaires' disease with 64 reported cases occurred in Ulm/Neu-Ulm in the South of Germany in December 2009/January 2010 caused by Legionella (L.) pneumophila serogroup 1, monoclonal (mAb) subtype Knoxville, sequence type (ST) 62. Here we present the clinical microbiological results from 51 patients who were diagnosed at the University hospital of Ulm, the results of the environmental investigations and of molecular typing of patients and environmental strains. All 50 patients from whom urine specimens were available were positive for L. pneumophila antigen when an enzyme-linked immunosorbent assay (EIA) was used following concentration of those urine samples that tested initially negative. The sensitivity of the BinaxNow rapid immunographic assay (ICA), after 15 min reading and after 60 min reading were 70% and 84%, respectively. Direct typing confirmed the monoclonal subtype Knoxville in 5 out of 8 concentrated urine samples. Real time PCR testing of respiratory tract specimens for L. pneumophila was positive in 15 out of 25 (60%) patients. Direct nested sequence based typing (nSBT) in some of these samples allowed partial confirmation of ST62. L. pneumophila serogroup 1, monoclonal subtype Knoxville ST62, defined as the epidemic strain was isolated from 8 out of 31 outbreak patients (26%) and from one cooling tower confirming it as the most likely source of the outbreak. While rapid detection of Legionella antigenuria was crucial for the recognition and management of the outbreak, culture and molecular typing of the strains from patients and environmental specimens was the clue for the rapid identification of the source of infection.

Genetic variation in IL28B and treatment-induced clearance of hepatitis C virus in HIV-positive patients with acute and chronic hepatitis C.

Recently, a IL28B (rs 12979860) gene polymorphism was identified as a predictor for response to hepatitis C virus-specific treatment in human immunodeficiency virus (HIV)-uninfected and -infected patients with chronic hepatitis C. In an analysis of HIV-infected patients with acute hepatitis C, we found that the IL28B genotype was associated with serum levels of hepatitis C virus RNA, g-GT, and CD4 cell count. In contrast to HIV-infected patients with chronic hepatitis C, the IL28B genotype was not significantly associated with treatment response rates in patients with acute hepatitis C. Thus, effects of the IL28B single-nucleotide polymorphism may differ in HIV-infected patients with chronic and acute hepatitis C.

Focal adhesion kinase mediates defects in the force-dependent reinforcement of initial integrin-cytoskeleton linkages in metastatic colon cancer cell lines.

Micro-environmental clues, including the biophysical interpretation of the extracellular matrix, are critical to proliferation, apoptosis and migration. Here, we show that metastatic human colon cancer cell lines display altered matrix interaction. Interaction of colon cancer cells with collagen I depends on integrins (mainly alpha(1)/beta(1)) but metastatic cells display delayed spreading and reduced extension of lamellipodia. In addition, cells show defective strengthening of integrin-cytoskeleton linkages upon mechanical stimulation, as determined by laser trapping experiments and binding of large beads to the cell surface. However, adhesion to pliable surfaces is ameliorated in metastatic variants. These changes are caused by constitutive activation of focal adhesion kinase (FAK) and can be modulated by changing expression and/or activity of FAK via RNA-interference or expression of inhibitory constructs, respectively. In addition, consistent with defective strengthening of integrin-cytoskeleton linkages, metastatic cell lines show reduced random motility. Taken together these data suggest that constitutive activation of FAK causes defects in spreading, reinforcement of integrin-cytoskeleton linkages and migration and at the same time could ameliorate the adhesion of metastatic cells to suboptimal surfaces.

Cytomegalovirus retinitis in a patient treated with anti-tumor necrosis factor alpha antibody therapy for rheumatoid arthritis.

BACKGROUND: Anti-tumor necrosis factor alpha (anti-TNF- alpha ) antibodies have been used for the treatment of chronic inflammatory diseases such as rheumatoid arthritis (RA) and psoriasis arthritis. Such antibody therapies result in a severe interference with the patient's immune system. Increased rates of upper respiratory tract infection, reactivation of latent tuberculosis, and other systemic infectious diseases have been reported among patients receiving anti-TNF- alpha antibodies. METHODS: As a note of caution, we describe a 57-year-old woman who received therapy with anti-TNF- alpha antibodies for RA refractory to methotrexate. After almost 2 years of treatment, she developed a severe cytomegalovirus (CMV) retinitis of the right eye. RESULTS: Laboratory assays revealed an immune status with nearly total loss of the cellular immune response and partial reduction of the humoral immune response. Intravenous treatment with ganciclovir, followed by oral administration of valganciclovir, resulted in an ophthalmological remission. Cessation of immunosuppressive therapy led to partial immunological reconstitution in the patient. Six months after discontinuation of immunosuppressive therapy, CMV retinitis of the left eye occurred but was treated successfully with a second course of oral valganciclovir. CONCLUSION: In the light of this first reported case of a serious CMV infection following therapy with anti-TNF- alpha antibodies, CMV infection should be considered in symptomatic patients.

Effect of the interleukin-6 C174G gene polymorphism on treatment of acute and chronic hepatitis C in human immunodeficiency virus coinfected patients.

UNLABELLED: Hepatitis C virus (HCV)/human immunodeficiency virus (HIV) coinfection poses a difficult therapeutic problem. Response to HCV-specific therapy is variable but might be influenced by host genetic factors, including polymorphisms of cytokine genes. Here, we studied whether interleukin-6 (IL-6) C174G gene polymorphism affects the response to antiviral treatment in HCV-infected HIV-positive subjects. We determined IL-6 genotypes in HIV-positive patients with acute (n = 52) and chronic (n = 60) hepatitis C treated with pegylated interferon-alpha. Two hundred ten HCV monoinfected, 197 HIV monoinfected, and 100 healthy individuals were studied as controls. Patients were classified into high and low producers according to IL-6 genotypes. Rates of sustained virological responses (SVRs) were compared between the IL-6 genotypes. Signal transducer and activator of transcription three phosphorylation was analyzed by Western blot in HCV core-transfected human hepatoma cell line (HUH7) cells. Distribution of IL-6 genotypes did not differ significantly between the study groups. SVR was achieved in 63% of HIV/HCV coinfected patients. Carriers of the IL-6 high producer (HP) genotype had significantly higher SVR rates than patients with an IL-6 low producer genotype (70.1% versus 52%; P < 0.002). This effect was seen in both HIV-positive patients with acute (74% versus 33%; P < 0.05) and chronic (66% versus 33%; P < 0.05) hepatitis C. Multivariate analysis confirmed IL-6 HP carriage as an independent positive predictor for SVR (Odd's ratio 6.1; P = 0.004). This effect corresponds to the in vitro observation that in HCV core-transfected HUH7 cells, IL-6 overcomes the HCV core-mediated inhibition of STAT3 activation. CONCLUSION: Response rates to HCV-specific treatment are higher in HCV/HIV-positive patients carrying the IL-6 HP genotype, which might be because of IL-6 mediated STAT3 activation.