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 - 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 -