TY - JOUR A1 - Rubio-Cosials, Anna A1 - Schulz, Eike C. A1 - Lambertsen, Lotte A1 - Smyshlyaev, Georgy A1 - Rojas-Cordova, Carlos A1 - Forslund, Kristoffer A1 - Karaca, Ezgi A1 - Bebel, Aleksandra A1 - Bork, Peer A1 - Barabas, Orsolya T1 - Transposase-DNA Complex Structures Reveal Mechanisms for Conjugative Transposition of Antibiotic Resistance JF - Cell N2 - Conjugative transposition drives the emergence of multidrug resistance in diverse bacterial pathogens, yet the mechanisms are poorly characterized. The Tn1549 conjugative transposon propagates resistance to the antibiotic vancomycin used for severe drug-resistant infections. Here, we present four high-resolution structures of the conserved Y-transposase of Tn1549 complexed with circular transposon DNA intermediates. The structures reveal individual transposition steps and explain how specific DNA distortion and cleavage mechanisms enable DNA strand exchange with an absolute minimum homology requirement. This appears to uniquely allow Tn916-like conjugative transposons to bypass DNA homology and insert into diverse genomic sites, expanding gene transfer. We further uncover a structural regulatory mechanism that prevents premature cleavage of the transposon DNA before a suitable target DNA is found and generate a peptide antagonist that interferes with the transposase-DNA structure to block transposition. Our results reveal mechanistic principles of conjugative transposition that could help control the spread of antibiotic resistance genes. KW - DNA complex KW - crystallography KW - Tn1549 transposon KW - Tn916-like transposon family KW - conjugative transposition KW - tyrosine recombinase KW - antibiotic resistance KW - gene transfer KW - vancomycin KW - multidrug-resistant bacteria Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227085 VL - 173 IS - 1 ER - TY - JOUR A1 - Rakette, Sonja A1 - Donat, Stefanie A1 - Ohlsen, Knut A1 - Stehle, Thilo T1 - Structural Analysis of Staphylococcus aureus Serine/Threonine Kinase PknB JF - PLoS One N2 - Effective treatment of infections caused by the bacterium Staphylococcus aureus remains a worldwide challenge, in part due to the constant emergence of new strains that are resistant to antibiotics. The serine/threonine kinase PknB is of particular relevance to the life cycle of S. aureus as it is involved in the regulation of purine biosynthesis, autolysis, and other central metabolic processes of the bacterium. We have determined the crystal structure of the kinase domain of PknB in complex with a non-hydrolyzable analog of the substrate ATP at 3.0 angstrom resolution. Although the purified PknB kinase is active in solution, it crystallized in an inactive, autoinhibited state. Comparison with other bacterial kinases provides insights into the determinants of catalysis, interactions of PknB with ligands, and the pathway of activation. KW - SER/THR kinase KW - domain KW - subunit KW - dependent protein-kinase KW - mycobacterium-tuberculosis KW - activation mechanism KW - crystal structure KW - antibiotic resistance KW - catalytic KW - methicillin KW - inhibitor Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135369 VL - 7 IS - 6 ER - TY - JOUR A1 - Kusan, Simon A1 - Surat, Güzin A1 - Kelm, Matthias A1 - Anger, Friedrich A1 - Kim, Mia A1 - Germer, Christoph-Thomas A1 - Schlegel, Nicolas A1 - Flemming, Sven T1 - Microbial spectrum and antibiotic resistance in patients suffering from penetrating Crohn's disease JF - Journal of Clinical Medicine N2 - Intraabdominal abscess formation occurs in up to 30% of patients suffering from Crohn's disease (CD). While international guidelines recommend a step-up approach with a combination of empiric antibiotic therapy and percutaneous drainage to delay or even avoid surgery, evidence about microbial spectrum in penetrating ileitis is sparse. We retrospectively assessed outcomes of 46 patients with terminal penetrating Ileitis where microbial diagnostics have been performed and compared microbial spectrum and antibiotic resistance profile of CD patients with patients suffering from diverticulitis with intraabdominal abscess formation. In both groups, the most frequently isolated pathogen was the gram-negative bacterium E. coli belonging to the family of Enterobacterales. However, overall Enterobacterales were significantly more often verifiable in the control group than in CD patients. Furthermore, microbial analysis showed significant differences regarding isolation of anaerobic pathogens with decreased frequency in patients with CD. Subgroup analysis of CD patients to evaluate a potential influence of immunosuppressive therapy on microbial spectrum only revealed that Enterobacterales was less frequently detected in patients treated with steroids. Immunosuppressive therapy did not show any impact on all other groups of pathogens and did not change antibiotic resistance profile of CD patients. In conclusion, we were able to demonstrate that the microbial spectrum of CD patients does differ only for some pathogen species without increased rate of antibiotic resistance. However, the empiric antibiotic therapy for CD-associated intra-abdominal abscess remains challenging since different points such as local epidemiological and microbiological data, individual patient risk factors, severity of infection, and therapy algorithm including non-surgical and surgical therapy options should be considered before therapeutical decisions are made. KW - Crohn's disease KW - intraabdominal abscess KW - penetrating ileitis KW - microbial spectrum KW - antibiotic resistance Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281835 SN - 2077-0383 VL - 11 IS - 15 ER - TY - JOUR A1 - Hetzer, Benjamin A1 - Orth-Höller, Dorothea A1 - Würzner, Reinhard A1 - Kreidl, Peter A1 - Lackner, Michaela A1 - Müller, Thomas A1 - Knabl, Ludwig A1 - Geisler-Moroder, Daniel Rudolf A1 - Mellmann, Alexander A1 - Sesli, Özcan A1 - Holzknecht, Jeanett A1 - Noce, Damia A1 - Akarathum, Noppadon A1 - Chotinaruemol, Somporn A1 - Prelog, Martina A1 - Oberdorfer, Peninnah T1 - “Enhanced acquisition of antibiotic-resistant intestinal E. coli during the first year of life assessed in a prospective cohort study” JF - Antimicrobial Resistance & Infection Control N2 - Background Increasing bacterial resistance to antibiotics is a serious problem worldwide. We sought to record the acquisition of antibiotic-resistant Escherichia coli (E. coli) in healthy infants in Northern Thailand and investigated potential determinants. Methods Stool samples from 142 infants after birth, at ages 2wk, 2mo, 4 to 6mo, and 1y, and parent stool samples were screened for E. coli resistance to tetracycline, ampicillin, co-trimoxazole, and cefazoline by culture, and isolates were further investigated for multiresistance by disc diffusion method. Pulsed-field gel electrophoresis was performed to identify persistent and transmitted strains. Genetic comparison of resistant and transmitted strains was done by multilocus sequence typing (MLST) and strains were further investigated for extra- and intra-intestinal virulence factors by multiplex PCR. Results Forty-seven (33%) neonatal meconium samples contained resistant E. coli. Prevalence increased continuously: After 1y, resistance proportion (tetracycline 80%, ampicillin 72%, co-trimoxazole 66%, cefazoline 35%) almost matched those in parents. In 8 infants (6%), identical E. coli strains were found in at least 3 sampling time points (suggesting persistence). Transmission of resistant E. coli from parents to child was observed in only 8 families. MLST showed high diversity. We could not identify any virulence genes or factors associated with persistence, or transmission of resistant E. coli. Full-term, vaginal birth and birth in rural hospital were identified as risk factors for early childhood colonization with resistant E. coli. Conclusion One third of healthy Thai neonates harboured antibiotic-resistant E. coli in meconium. The proportion of resistant E. coli increased during the first year of life almost reaching the value in adults. We hypothesize that enhancement of infection control measures and cautious use of antibiotics may help to control further increase of resistance. KW - Escherichia coli KW - antibiotic resistance KW - multiresistance KW - transmission KW - persistence KW - children KW - neonates Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-320284 VL - 8 ER - TY - THES A1 - Götz, Carolin T1 - Intraorale Weichteilinfektionen : eine retrospektive Untersuchung von 244 Patienten T1 - Oral soft tissue infections-a retrospective analysis of 244 patients N2 - Introduction Intraoral soft tissue infections (OSTI) are a common problem in dentistry and oral surgery. These abscesses are mostly exacerbated dental infections (OIDC), and some emerge as postoperative infections (POI) after tooth extraction (OITR) or apicoectomy (OIRR). The main aim of this study was to compare OIDC with POI, especially looking at the bacteria involved. An additional question was, therefore, if different antibiotic treatments should be used with OSTI of differing aetiologies. The impact of third molars on OSTI was evaluated and also the rates of POI after removal of third molars were specified. Materials and methods Patient data was collected from the patients' medical records and the results were statistically evaluated with SPSS (SPSS version 21.0; SPSS, IBM; Chicago, IL, USA). The inclusion criterion was the outpatient treatment of a patient with an exacerbated oral infection; the exclusion criteria were an early stage of infiltration without abscess formation; and a need for inpatient treatment. Results Periapical exacerbated infections, especially in the molar region were the commonest cause of OIDC. In the OITR group, mandibular tooth removal was the commonest factor (p=0.016). Remarkably, retained lower wisdom teeth led 91 to significant number of cases in the OITR group (p=0.022). Conclusions In our study we could not define differences between the causal bacteria found in patients with OIDC and POI. Due to resistance rates we conclude that amoxicillin combined with clavulanic acid seems to be the antibiotic standard for exacerbated intraoral infections independent of their aetiology. N2 - Einführung Intraorale Weichteilinfektionen (OSTI) sind ein häufiges Problem in der Zahnmedizin und Kieferchirurgie. Diese Abszesse sind meist dentalen Ursprungs(OIDC), einige wiederum treten als postoperative Infektionen (POI) nach einer Zahnextraktion (OITR) oder Wurzelspitzenresektion (Oirr) auf. Das Hauptziel dieser Studie war es OIDC mit POI zu vergleichen. Ein weiteres Ziel war es, die unterschiedlichen antibiotischen Behandlungen bei OSTI unterschiedlicher Ätiologien gegeneinander abzuwägen. Die Auswirkungen der dritten Molaren auf OSTI wurde ebenfalls untersucht, und auch die Rate von POI nach Entfernung der dritten Molaren wurden angegeben. Material und Methode Die Patientendaten wurden durch die Analyse der Aufzeichnungen und Akten erhoben. Die Ergebnisse wurden statistisch ausgewertet mit SPSS (SPSS Version 21.0, SPSS, IBM, Chicago, IL, USA). Einschlusskriterium war die ambulante Behandlung eines Patienten mit dem Krankheitsbild einer intraoralen Infektion. Die Ausschlusskriterien waren ein frühes Stadium der Infiltration ohne Abszessbildung und die Notwendigkeit einer stationären Behandlung. Ergebnisse Apikale Parodontitiden, vor allem im Bereich der Molaren waren die häufigste Ursache für OIDC. In der OITR Gruppe war Zahnentfernung die häufigste Ursache (p = 0,016). Bemerkenswerterweise führte die Entfernung von unteren Weisheitszähnen zu einer erheblichen Anzahl von Fällen in der OITR Gruppe (p = 0,022). Schlussfolgerungen In unserer Studie konnten wir keine Unterschiede zwischen der bakteriellen Flora bei Patienten mit OIDC und POI erörtern. Aufgrund der aktuellen Resistenzraten, ziehen wir die Schlussfolgerung, dass Amoxicillin kombiniert mit Clavulansäure das Antibiotikum der Wahl für intraorale Infektionen, unabhängig von deren Ätiologie, zu sein scheint. KW - Weltgesundheitsorganisation. Expert Committee on Prevention Methods and Programmes for Oral Diseases KW - American Association of Oral and Maxillofacial Surgeons KW - Intraorale Infektionen KW - Oral soft tissue infections KW - Weisheitszahnextraktion KW - Antibiotikatherapie KW - third molar surgery KW - postoperative complications KW - antibiotics in oral surgery KW - antibiotic resistance Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133614 ER - TY - JOUR A1 - Gágyor, Ildikó A1 - Greser, Alexandra A1 - Heuschmann, Peter A1 - Rücker, Viktoria A1 - Maun, Andy A1 - Bleidorn, Jutta A1 - Heintze, Christoph A1 - Jede, Felix A1 - Eckmanns, Tim A1 - Klingeberg, Anja A1 - Mentzel, Anja A1 - Schiemann, Guido T1 - REDuction of Antibiotic RESistance (REDARES) in urinary tract infections using treatments according to national clinical guidelines: study protocol for a pragmatic randomized controlled trial with a multimodal intervention in primary care JF - BMC Infectious Diseases N2 - Background: Urinary tract infections (UTIs) are a common cause of prescribing antibiotics in family medicine. In Germany, about 40% of UTI-related prescriptions are second-line antibiotics, which contributes to emerging resistance rates. To achieve a change in the prescribing behaviour among family physicians (FPs), this trial aims to implement the guideline recommendations in German family medicine. Methods/design: In a randomized controlled trial, a multimodal intervention will be developed and tested in family practices in four regions across Germany. The intervention will consist of three elements: information on guideline recommendations, information on regional resistance and feedback of prescribing behaviour for FPs on a quarterly basis. The effect of the intervention will be compared to usual practice. The primary endpoint is the absolute difference in the mean of prescribing rates of second-line antibiotics among the intervention and the control group after 12 months. To detect a 10% absolute difference in the prescribing rate after one year, with a significance level of 5% and a power of 86%, a sample size of 57 practices per group will be needed. Assuming a dropout rate of 10%, an overall number of 128 practices will be required. The accompanying process evaluation will provide information on feasibility and acceptance of the intervention. Discussion: If proven effective and feasible, the components of the intervention can improve adherence to antibiotic prescribing guidelines and contribute to antimicrobial stewardship in ambulatory care. KW - antibiotic resistance KW - urinary tract infections KW - guideline adherence KW - multimodal KW - family physicians KW - primary care Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264725 VL - 21 ER - TY - JOUR A1 - Abda, Ebrahim M. A1 - Krysciak, Dagmar A1 - Krohn-Molt, Ines A1 - Mamat, Uwe A1 - Schmeisser, Christel A1 - Förstner, Konrad U. A1 - Schaible, Ulrich E. A1 - Kohi, Thomas A. A1 - Nieman, Stefan A1 - Streit, Wolfgang R. T1 - Phenotypic Heterogeneity Affects Stenotrophomonas maltophilia K279a Colony Morphotypes and \(\beta\)-Lactamase Expression JF - Frontiers in Microbiology N2 - Phenotypic heterogeneity at the cellular level in response to various stresses, e.g., antibiotic treatment has been reported for a number of bacteria. In a clonal population, cell-to-cell variation may result in phenotypic heterogeneity that is a mechanism to survive changing environments including antibiotic therapy. Stenotrophomonas rnaltophilia has been frequently isolated from cystic fibrosis patients, can cause numerous infections in other organs and tissues, and is difficult to treat due to antibiotic resistances. S. maltophilia K279a produces the Li and L2 beta-lactamases in response to beta-lactam treatment. Here we report that the patient isolate S. rnaltophilia K279a diverges into cellular subpopulations with distinct but reversible morphotypes of small and big colonies when challenged with ampicillin. This observation is consistent with the formation of elongated chains of bacteria during exponential growth phase and the occurrence of mainly rod-shaped cells in liquid media. RNA-seq analysis of small versus big colonies revealed differential regulation of at least seven genes among the colony morphotypes. Among those, bleu and bla(L2) were transcriptionally the most strongly upregulated genes. Promoter fusions of b/a(L1) and b/a(L2) genes indicated that expression of both genes is also subject to high levels of phenotypic heterogeneous expression on a single cell level. Additionally, the comE homolog was found to be differentially expressed in homogenously versus heterogeneously bla(L2) expressing cells as identified by RNA(seq) analysis. Overexpression of cornE in S. maltophilia K279a reduced the level of cells that were in a bla(L2)-ON mode to 1% or lower. Taken together, our data provide strong evidence that S. maltophilia K279a populations develop phenotypic heterogeneity in an ampicillin challenged model. This cellular variability is triggered by regulation networks including b/a(L1), b/a(L2), and comE. KW - xanthomonas maltophilia KW - gram-negative bacteria KW - RNA-seq KW - pseudomas aeruginosa KW - antibiotic resistance KW - colony morphotypes KW - beta-lactamases KW - K279a KW - Stenotrophomonas maltophilia KW - phenotypic heterogeneity KW - persister cells KW - streptococcus pneumoniae KW - nosocomial pathogen KW - membrane vesicles KW - sinorhizobium fredii NGR234 KW - red fluorescent protein KW - escherichia coli Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-136446 VL - 6 IS - 1373 ER -