Uciechowski P.,RWTH Aachen |
Imhoff H.,RWTH Aachen |
Lange C.,Medical Clinic |
Meyer C.G.,Bernhard Nocht Institute for Tropical Medicine |
And 11 more authors.
Journal of Leukocyte Biology | Year: 2011
Human TLR1 plays an important role in host defense against Mycobacterium tuberculosis. Our aim was to analyze the association of the loss of TLR1 surface expression and TLR1 SNPs with susceptibility to TB. TLR1neg and TLR1pos cells from healthy individuals were identified by flow cytometry and compared by sequencing. TLR1 expression was measured using quantitative real-time PCR and immunoblotting. TLR1 SNP analyses of healthy individuals and TB patients from EU-C and Ghana were performed, and association of the TLR1 genotypes with increased risk of developing TB was statistically evaluated. Lack of TLR1 surface expression accompanied by impaired function was strongly associated with TLR1 SNP G743A. Genotyping of EU-C controls and TB patients revealed an association of TLR1 743A/1805G alleles [OR 2.37 (95% CI 1.13, 4.93), P=0.0219; OR 2.74 (95% CI 1.26, 6.05), P=0.0059] as well as TLR1neg 743AA/1805GG versus TLR1pos genotypes 743AG/1805TG [OR 4.98 (95% CI 1.64, 15.15), P=0.0034; OR 5.70 (95% CI 1.69, 20.35), P=0.0015] and 743AG + GG/1805TG + TT [OR 3.54 (95% CI 1.29, 9.90), P=0.0086; OR 4.17 (95% CI 1.52, 11.67), P=0.0025] with increased susceptibility to TB. No association of G743A with TB was found in Ghana as a result of a low frequency of genotype 743AA. Our data gain new insights in the role of TLR1 in M. tuberculosis defense and provide the first evidence that TLR1 variants are associated with susceptibility to TB in a low-incidence country. © Society for Leukocyte Biology.
Schaumburg F.,Institutes of Medical Microbiology |
Schaumburg F.,Medical Research Unit |
Alabi A.S.,Medical Research Unit |
Alabi A.S.,University of Tubingen |
And 8 more authors.
Environmental Microbiology Reports | Year: 2012
Staphylococcus aureus is a bacterium that colonizes and infects both humans and animals. As little is known about the phenotypic and molecular characteristics of S.aureus from wild animals in sub-Saharan Africa, the objective of the study was to characterize S.aureus isolates from wildlife and to analyse if they differed from those found among humans. The resistance to penicillin was low in S.aureus isolates from non-human primates (2.9%). Phylogenetic analysis based on the concatenated sequences from multilocus sequence typing revealed two highly divergent groups of isolates. One group was predominated by S.aureus that belonged to known human-related STs (ST1, ST9 and ST601) and mainly derived from great apes. A second clade comprised isolates with novel STs. These isolates were different from classical human S.aureus strains and mainly derived from monkeys. Our findings provide the basis for future studies addressing the inter- and intra-species transmission of S.aureus in Africa. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
Vonberg R.P.,Hannover Medical School |
Hohle M.,Robert Koch Institute |
Aepfelbacher M.,Institute of Medical Microbiology |
Bange F.C.,Hannover Medical School |
And 21 more authors.
Clinical Infectious Diseases | Year: 2013
Background. In May-July 2011, Germany experienced a large food-borne outbreak of Shiga toxin 2-producing Escherichia coli (STEC O104:H4) with 3842 cases, including 855 cases with hemolytic uremic syndrome (HUS) and 53 deaths.Methods. A multicenter study was initiated in 5 university hospitals to determine pathogen shedding duration. Diagnostics comprised culture on selective media, toxin enzyme-linked immunosorbent assay, and polymerase chain reaction. Results were correlated with clinical and epidemiologic findings. Testing for pathogen excretion was continued after discharge of the patient.Results. A total of 321 patients (104 male, 217 female) were included (median age, 40 years [range, 1-89 days]). Median delay from onset of symptoms to hospitalization was 4 days (range, 0-17 days). Two hundred nine patients presented with HUS. The estimate for the median duration of shedding was 17-18 days. Some patients remained STEC O104:H4 positive until the end of the observation time (maximum observed shedding duration: 157 days). There was no significant influence of sex on shedding duration. Patients presenting with HUS had a significantly shortened shedding duration (median, 13-14 days) compared to non-HUS patients (median, 33-34 days). Antimicrobial treatment was also significantly associated with reduced shedding duration. Children (age ≤15 years) had longer shedding durations than adults (median, 35-41 vs 14-15 days).Conclusions. STEC O104:H4 is usually eliminated from the human gut after 1 month, but may sometimes be excreted for several months. Proper follow-up of infected patients is important to avoid further pathogen spread. © 2013 The Author 2013.