Conjugative IncFI plasmids carrying CTX-M-15 among Escherichia coli ESBL producing isolates at a University hospital in Germany

<p>Abstract</p> <p>Background</p> <p>Multi-drug-resistant, extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, constitute an emerging public-health concern. Little data on the molecular epidemiology of ESBL producing <it>Escherichia coli </it>is available in Germany. Here we describe the prevalence and molecular epidemiology of ESBL producing-<it>Escherichia coli </it>isolates at a German University hospital.</p> <p>Methods</p> <p>We analysed 63 non-duplicate clinical ESBL isolates obtained over an 8-month period using PCR and sequence-based ESBL allele typing, plasmid replicon typing, phylogenetic group typing. Pulsed-field gel electrophoresis (PFGE) based genotyping and plasmid profiling was performed, as well as confirmatory DNA-based hybridization assays.</p> <p>Results</p> <p>Examination of the 63 <it>Escherichia coli </it>isolates revealed an almost equal distribution among the <it>E. coli </it>phylogenetic groups A, B1, B2 and D. High prevalence (36/63) of the CTX-M-15 gene was observed and an analysis of PFGE-based patterns revealed the presence of this CTX-M allele in multiple clones. Resistance to cefotaxime was a transferable trait and a commonly occurring 145.5 kb conjugative IncFI plasmid was detected in 65% of <it>E. coli </it>carrying the CTX-M-15 allele. The rate of transferable antibiotic resistances for GM, SXT, TET, GM-SXT-TET, SXT-TET and GM-TET was 33%, 61%, 61%, 27%, 44% and 11%, respectively. The remaining strains did not have a common IncFI plasmid but harboured transferable IncFI plasmids with sizes that ranged from 97 to 242.5 kb.</p> <p>Conclusion</p> <p>Our data demonstrate the presence of IncFI plasmids within the prevailing <it>E. coli </it>population in a hospital setting and suggest that the dissemination of CTX-M-15 allele is associated to lateral transfer of these well-adapted, conjugative IncFI plasmids among various <it>E. coli </it>genotypes.</p

How valid are current diagnostic criteria for dental erosion?

In principle, there is agreement about the clinical diagnostic criteria for dental erosion, basically defined as cupping and grooving of the occlusal/incisal surfaces, shallow defects on smooth surfaces located coronal from the enamel–cementum junction with an intact cervical enamel rim and restorations rising above the adjacent tooth surface. This lesion characteristic was established from clinical experience and from observations in a small group of subjects with known exposure to acids rather than from systematic research. Their prevalence is higher in risk groups for dental erosion compared to subjects not particularly exposed to acids, but analytical epidemiological studies on random or cluster samples often fail to find a relation between occurrence or severity of lesions and any aetiological factor. Besides other aspects, this finding might be due to lack of validity with respect to diagnostic criteria. In particular, cupping and grooving might be an effect of abrasion as well as of erosion and their value for the specific diagnosis of erosion must be doubted. Knowledge about the validity of current diagnostic criteria of different forms of tooth wear is incomplete, therefore further research is needed

The usefulness of microscopic observation for drug susceptibility of Mycobacterium tuberculosis complex in routine clinical microbiology laboratory

Clinical management of tuberculosis (TB) cases in developing countries is hampered by the lack of a simple and effective diagnostic test. Correct diagnosis of TB is needed to improve treatment, reduce transmission, and control development of drug resistance. This study was undertaken to establish microscopic observation for drug susceptibility (MODS) in clinical microbiology routine. Thirty Mycobacterium tuberculosis isolates and four smear positive sputum specimens were tested for susceptibility to isoniazid, rifampicin, ethambutol and streptomycin using MODS. Results were compared to gold standard methods used at a TB reference laboratory. The median turn around time (TAT) was six days for both direct and indirect assays. Results for rifampicin were 100% concordant with the reference laboratory and those of ethambutol, streptomycin and isoniazid were 97%, 94% and 94% concordant, respectively. In all discordant cases MODS categorize the isolates as resistant. Using SYBR Green to detect growth, there was clear increase in fluorescence for cultures of drug-resistant strains when compared to culture of sensitive strains. The discrepancy in these cases can be explained by the fact that in MODS any growth in drug-containing wells is labelled as resistance and can be resolved in using SYBR Green. MODS can therefore, be considered as a reliable and fast method which could be used as routine in Clinical Microbiology Laboratory in a TB endemic area

Epidemiologie der Verona-Integron-Metallo-ß-Laktamasen (VIM) in Hessen, 2012 – 2016

Carbapeneme sind wichtige Antibiotika für die Behandlung multiresistenter gramnegativer Erreger. Die weltweite Ausbreitung Carbapenemase-produzierender Erreger wird als Bedrohung für die Gesundheitsversorgung angesehen. In Hessen bestand seit Ende 2011 eine Meldepflicht für den Nachweis Carbapenem-resistenter gramnegativer Erreger. Aufgrund der bundesweiten Einführung einer Meldepflicht für Carbapenem-nichtempfindliche Erreger zum 1. Mai 2016 wurde die auf einen Fünfjahreszeitraum befristete hessische Verordnung nicht verlängert. Damit endete die Meldepflicht für Carbapenem-resistente P. aeruginosa zum 31. Dezember 2016. Carbapenemasen werden auf Basis ihrer Aminosäurensequenz in unterschiedliche Gruppen eingeteilt. Verona-Integron-Metallo-ß-Laktamasen (VIM) gehören, wie die New-Delhi-Metallo-ß-Laktamasen (NDM), zur Familie der Metallo-ß-Laktamasen. Im Epidemiologischen Bulletin 49/2017 werden die hessischen Meldedaten zu Carbapenem-resistenten gramnegativen Erregern mit molekularbiologischem Nachweis einer VIM ausgewertet. Das Fazit der Autoren lautet: Verschiedene VIM-Varianten sind in Hessen endemisch. Die Meldepflicht für Carbapenemase-produzierende P. aeruginosa und die Ergebnisse der Ganzgenomsequenzierung waren hilfreich für die Bestätigung bzw. den Ausschluss von Erregerübertragungen. Nur für wenige Patienten mit Nachweis VIM-produzierender Erreger konnte ein wahrscheinlicher Übertragungsweg ermittelt werden

Results on the mandatory notification of carbapenem-resistant Gram-negative bacteria, Hesse, Germany, January 2012 - April 2013

Carbapenems are important therapeutic agents for treating infections caused by multidrug-resistant Gram-negative bacteria. Mandatory reporting of carbapenem-resistant Gram-negative bacteria (CR-GN) can allow for a better understanding of the changing CR-GN burden and can help facilitate intervention. In November 2011, identification of CR-GN with acquired carbapenem resistance became notifiable in Hesse, Germany. Hesse is one of the 16 German federal states, with a population of 6.1 million. We report on CR-GN notified between 1 January and 8 April 2013, when reporting requirements were changed. During this period, 549 CR-GN were isolated from 525 patients. Of these, 67.0% (368/549) were Pseudomonas aeruginosa . The remaining 181 CR-GN comprised 59 (32.6%) K. pneumoniae , 53 (29.3%) Acinetobacter baumannii , 28 (15.5%) Enterobacter spp., 20 (11.5%) E. coli , and 21 (11.6%) other CR-GN. Seventy-three (13.3%) CR-GN were reported to harbour a carbapenemase. Fourteen different carbapenemase types were reported, with the most frequent being OXA-23 (n=18), OXA-48 (n= 16), VIM-2 (n=12), VIM-1 (n=11), and NDM (n=5). Our results suggest the widespread presence of CR-GN, a high diversity of identified carbapenemases, autochthonous transmissions, and regional differences in incidence for the different species and carbapenemases, even in the absence of major outbreaks of infection