We report an objective examination of nosocomial transmission events derived from long-term (10-year) data from a single medical centre. Cluster analysis, based on the temporal proximity of genetically identical isolates of the respiratory pathogen Moraxella catarrhalis, identified 40 transmission events involving 33 of the 52 genotypes represented by multiple isolates. There was no evidence of highly transmissible or outbreak-prone genotypes. Although most clusters were small (mean size 3·6 isolates) and of short duration (median duration 25 days), clustering accounted for 38·7% of all isolates. Significant risk factors for clustering were multi-bed wards, and winter and spring season, but bacterial antibiotic resistance, manifested as the ability to produce a β-lactamase was not a risk factor. The use of cluster analysis to identify transmission events and its application to long-term data demonstrate an approach to pathogen transmission that should find wide application beyond hospital populations.

The evolution of antibiotic resistance provides a well-documented, rapid, and recent example of a selection driven process that has occurred in many bacterial species. An exhaustive collection of Moraxella catarrhalis that spans a transition to chromosomally encoded penicillin resistance was used to analyze genetic changes accompanying the transition. The population was characterized by high haplotypic diversity with 148 distinct haplotypes among 372 isolates tested at three genomic regions. The power of a temporally stratified sample from a single population was highlighted by the finding of high genetic diversity throughout the transition to resistance, population numbers that remained high over time, and no evidence of departures from neutrality in the allele frequency spectra throughout the transition. The direct temporal analysis documented the persistence, antibiotic status, and haplotypic identity of strains undergoing apparent clonal expansions. Several haplotypes that were β-lactamase nonproducers in early samples converted to producers in later years. Maintenance of genetic diversity and haplotype conversions from sensitive to resistant supported the hypothesis that penicillin resistance determinants spread to a diverse array of strains via horizontal exchange. Genetic differentiation between sample years, estimated by FST, was increasing at a rate that could cause complete haplotype turnover in less than 150 years. Widespread linkage disequilibrium among sites within one locus (copB) suggested recent mutation followed by clonal expansion. Nonrandom associations between haplotypes and resistance phenotypes provided further evidence of clonal expansion for some haplotypes. Nevertheless, the population structure was far from clonal as evidenced by a relatively low frequency of disequilibria both within sites at a second locus (M46) as well as between loci. The haplotype-antibiotic resistance association that was accompanied by gradual haplotype turnover is consistent with a hypothesis of genetic drift at marker loci with directional selection at the resistance locus.

Antimicrobial susceptibility profiles were assembled for isolates of Moraxella catarrhalis collected from the Mountain Home Veteran's Affairs Medical Center (VAMC) clinical laboratory in Johnson City, Tennessee. The goal of the study was to identify isolates for genetic characterization using comparisons of susceptibility profiles. Isolates of Moraxella catarrhalis collected from July 1984 through 1994 were analyzed for β-lactamase production using a Cefinase disk assay. A multi-drug profile consisting of 11 β-lactam antibiotics was performed on the 41 M. catarrhalis isolates. Kirby Bauer disk assays were performed for 7 cephalosporin and 4 non-cephalosporin antibiotics. In summary, 2 observations implicate more complex resistance determinants than the 2 known forms of the BRO β-lactamase. First, there was overlap in the ranges of inhibition zones. Second, several isolates had antibiotic-specific deviations from typical profiles. These data suggest either more variation in the M. catarrhalis BRO β-lactamase than described or contributions to resistance from undescribed determinants.

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Die COPD (chronic obstructive pulmonary disease) ist eine weltweit vorkommende, chronisch obstruktive Erkrankung der Lunge. Sie gilt als vierthäufigste Todesursache weltweit, wobei ein Viertel der akuten bakteriellen Exazerbationen auf eine Infektion mit Moraxella catharralis zurückzuführen sind. Sowohl das akute, als auch das chronische Entzündungsbild der COPD wird überwiegend durch neutrophile Granulozyten in den Atemwegen bestimmt, die neben antimikrobiellen Effektorfunktionen durch Freisetzung von Zytokinen auch die Entzündungsreaktion bzw. Immunantwort regulieren können. In dieser Arbeit wurde untersucht inwiefern die Interaktion von M.catarrhalis mit dem humanen Granuloyzten-spezifischen Rezeptor carcinoembryonic antigen-related cell adhesion molecule (CEACAM)3 zu einer Aktivierung der neutrophilen Granuloyzten sowie zu einer NF-kappaB-abhängigen Chemokinproduktion führt. Primäre Granulozyten gesunder Spender sowie NB4 Zellen wurden mit M.catarrhalis in Anwesenheit verschiedener Inhibitoren, siRNA oder CEACAM-blockender Antikörper infiziert und anschließend die Chemokinsekretion mittels ELISA bestimmt. Mit Hilfe eines Luziferase Reportergenassays und Chromatinimmunpräzipitation wurde die Aktivierung des Transkriptionsfaktors NF-kappaB untersucht. Im Rahmen dieser Arbeit konnte nachgewiesen werden, dass die spezifische Interaktion von CEACAM3 mit M. catarrhalis UspA1 in einer Aktivierung neutrophiler Granulozyten resultiert. Desweiteren kommt es zu einer CEACAM3-UspA1 abhängigen Aktivierung des Transkriptionsfaktors NF-kappaB und verstärkter Sekretion proinflammatorischer Chemokine. Die NF-kappaB-Aktivierung ist abhängig von der Phosphorylierung des CEACAM3 ITAM-like Motivs und erfolgt über den Syk und Card9 Signalweg. Die Ergebnisse lassen den Schluss zu, dass neutrophile Granulozyten in der Lage sind, die durch M. catarrhalis induzierte Atemwegsentzündung in der COPD über den Oberflächenrezeptor CEACAM3 spezifisch zu modulieren. / The chronic obstructive pulmonary disease (COPD) is the fourth most common cause of death worldwide. 25 % of the acute bacterial exacerbations are caused by infection with the human restricted pathogen Moraxella catharralis. Both the acute and the chronic inflammatory stage of COPD are predominantly determined by neutrophil granulocytes in the respiratory tract, which in addition to antimicrobial effector functions can also regulate the inflammation or immune response by releasing cytokines. This work investigated if the interaction of M. catarrhalis with the human granulocyte-specific receptor carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 3 leads to an activation of the neutrophil granulocytes and to a NF-kappaB-dependent chemokine production. Primary granulocytes from healthy donors as well as NB4 cells were infected with M. catarrhalis in the presence of various inhibitors, siRNA or CEACAM-blocking antibodies, and then chemokine secretion was determined by ELISA. Using a luciferase reporter gene assay and chromatin immunoprecipitation, activation of the transcription factor NF-kappaB was investigated. In this work it could be shown that the specific interaction of CEACAM3 with M. catarrhalis UspA1 results in the activation of neutrophil granulocytes. Furthermore, there is a CEACAM3-UspA1-dependent activation of the transcription factor NF-kappaB and increased secretion of proinflammatory chemokines. NF-kappaB activation is dependent on the phosphorylation of the CEACAM3 ITAM-like motif and occurs via the Syk and Card9 signaling pathways. The results suggest that neutrophil granulocytes are able to specifically modulate M. catarrhalis induced airway inflammation in COPD via the surface receptor CEACAM3.

<p>Försämrat immunförsvar och ökad risk att drabbas av bakterie- och virusinfektioner förekommer hos patienter med blodsjukdomarna multipelt myelom, Waldenströms makroglobulinemi samt hos vissa patienter med blodsjukdomen monoklonal gammopati av oklar signifikans. Infektionerna kräver ofta antibiotikabehandling och behandling med antivirala medel. I dagsläget är det svårt att förutsäga vilka av patienterna som kommer att drabbas av svåra och ibland livshotande infektioner. Därför ges många av patienterna förebyggande antibiotikabehandling.</p><p>I studiens början sattes en enzyme-linked immunosorbent assay (ELISA) för detektion av antikroppar mot <em>Moraxella catarrhalis </em>upp. I studien undersöktes om antikroppstitrar i serum mot bakterien <em>Moraxella catarrhalis</em> var lägre hos patientgrupperna än hos friska kontrollpersoner i samma ålder och om variationer förekom mellan patientgrupperna samt hur kontrollgrupper i olika åldrar skiljde sig från varandra. Kontrollgrupperna som undersöktes var mellan 20-40 år, 40-60 år samt 60 år och äldre.</p><p>Resultatet var att patienterna med multipelt myelom hade lägst antikroppstitrar, patienter med monoklonal gammopati av oklar signifikans hade något högre och patienter med Waldenströms makroglobulinemi hade ännu högre antikroppstitrar. Kontrollgruppen äldre än 60 år hade högre antikroppstitrar än både kontrollgruppen 20-40 år och 40-60 år. Lägst antikroppstitrar hade kontrollgrupp 40-60 år men ingen signifikant skillnad påvisades mellan kontrollgrupp 20-40 år och 40-60 år.</p>

Nematodes of the genus Phasmarhabditis (Nematoda: Rhabditidae) are world-wide distributed molluscs´ parasites. Species P. hermaphrodita is the only commercially produced bio-agent for slug control. The aim of this thesis is to evaluate some ecologic characteristics of three newly described species of the genus Phasmarhabditis (P. bohemica, P. bonaquaense a P. apuliae) in polyxenic and monoxenic cultures. Three bacterial isolates, Pseudomonas sp., Acinetobacter sp. and Flavobacterium sp. were chosen for testing the monoxenic cultures. The growing ability of tested nematodes, the effect on the quality of progeny and the rate of development were examined on various organic substrates (compost, faeces of Deroceras slugs, homogenized Deroceras slugs, homogenized larvae of Galleria mellonella and homogenized pig kidney). Subsequently, the growth of nematodes was tested in solid and liquid media. The last experiment was focused on evaluating the impact of polyxenic and monoxenic nematode cultures on the mortality and feeding activity of Deroceras reticulatum and Cepaea hortensis. As is assumed in the results chapter, all examined species of nematodes are lethal facultative parasites of Deroceras spp. They are able to grow in broad spectre of organic substrates and bacteria which influence the production of the progeny, but the qualitative parameters of dauer juveniles remain more or less unaffected.

<p>Acute otitis media (AOM) is a common disease in childhood and is one of the most common causes for outpatient antibiotic treatment. The major aetiological agents of AOM have varied over the decades. Now the three most common pathogens are <i>Streptococcus pneumoniae</i>, <i>Haemophilus influenzae</i> and <i>Moraxella catarrhalis</i>. The resistance patterns of these organisms have also varied from the beginning of the antibiotic era to the situation we have today with an increasing incidence of penicillin-resistant <i>S. pneumoniae</i> and a moderate to high frequency of beta-lactamase production in <i>H. influenzae</i> and <i>M. catarrhalis</i>. In Sweden we have continued to use the Scandinavian treatment policy of penicillins as the first-line antibiotic treatment of AOM, which has been implemented with good results in the past. The question is if this policy will continue to have acceptable treatment results.</p><p>In order to investigate aspects of treatment, protection and structural changes in AOM, an animal model was used.</p><p>Amoxicillin treatment of AOM caused by <i>H. influenzae</i> was studied. Amoxicillin treatment was shown to shorten the duration of the infection and to reduce the morphological changes normally observed after an untreated AOM. The influence of antibiotic treatment on recurrent AOM was evaluated. Amoxicillin treatment did not lead to less protection against reinfection. Abstaining from antibiotics did not improve the levels of serum IgG antibodies. The IgG levels were significantly higher in treated animals after rechallenge. AOM caused by <i>H</i>. <i>influenzae</i> with a non-beta-lactamase-mediated resistance to beta-lactams was investigated and it was observed that during amoxicillin treatment the chromosomal changes mediating resistance were possibly advantageous for the bacterium. In cultures from children with AOM, there is sometimes growth of several bacteria. The possibility of a sheltering effect of beta-lactamase-producing <i>H. influenzae</i> on a penicillin-sensitive <i>S. pneumoniae</i> in a mixed infection was investigated, and amoxicillin was shown to eradicate the pneumococci from the middle ear despite the presence of beta-lactamase. An increasingly cultured bacterium in nasopharynx and in AOM is <i>M. catarrhalis</i>. It is now beta-lactamase-producing in almost 100% of cases and is thus not eradicated by penicillins. An animal model of AOM caused by beta-lactamase-producing <i>M. catarrhalis</i> was established to study the course of this infection with the possibility of evaluating aspects of virulence between AOM pathogens. The AOM observed was a self-limiting disease.</p><p>The results obtained in this study in a rat model support the continuing use of penicillins as first-line drugs in the treatment of AOM. Penicillins are not sufficient to treat all causative agents, but the majority of pathogens including the most virulent bacteria are eradicated from the middle ear. </p>