Microbiological and Clinical Significance of a New Property of Defective Lysis in Clinical Strains of Pneumococci

A pneumococcal isolate that caused relapsing meningitis in a patient infected with human immunodeficiency virus (HIV) was found to display an unusual response to penicillin - rapid death but a striking lack of cellular lysis. This lytic defect was also detected in all four pneumococcal isolates from three additional HIV-infected patients and in more than half of the clinical isolates from patients with bacteremia. In a rabbit model of meningitis, the lysis-defective strain remained cryptic, with a delay of 5 h in the onset of leukocytosis in cerebrospinal fluid. A marked burst of leukocytosis was associated with ampicillin-induced lysis of a lysis-sensitive strain but not of a lysis-defective strain. Pneumococcal clinical isolates have different lytic responses to penicillin; defective lysis may adversely affect the course of meningitis, an observation suggesting that autolysins play a role in modulating infectious disease

New fused triazinium systems from (alkoxycarbonyl)azinium N-aminides

2-(Alkoxycarbonyl)cycloimmonium N-aminides are efficient 1,4-dipoles that react with different types of reagents such as carbodiimides, benzoyliso(thio)cyanates and heterocyclic imidoyl chlorides to give new heterobetaines containing fused [l,2,4]triazinium systems.Plan Nacional de Investigación Científica, Desarrollo e Innovacíón Tecnológic

Antimicrobial Resistance in Enterococcus spp. Isolated from Environmental Samples in an Area of Intensive Poultry Production

Enterococcus spp. from two poultry farms and proximate surface and ground water sites in an area of intensive poultry production were tested for resistance to 16 clinical antibiotics. Resistance patterns were compared to assess trends and possible correlations for specific antimicrobials and levels of resistance. Enterococci were detected at all 12 surface water sites and three of 28 ground water sites. Resistance to lincomycin, tetracycline, penicillin and ciprofloxacin in poultry litter isolates was high (80.3%, 65.3%, 61.1% and 49.6%, respectively). Resistance in the surface water to the same antibiotics was 87.1%, 24.1%, 7.6% and 12.9%, respectively. Overall, 86% of litter isolates, 58% of surface water isolates and 100% of ground water isolates were resistant to more than one antibiotic. Fifty-four different resistance patterns were recognised in isolates obtained from litter and environmental samples and several E. faecium and E. faecalis isolates from litter and environment samples shared the same resistance pattern. Multiple antibiotic resistant (MAR) indices calculated to assess health risks due to the presence of resistant enterococci suggested an increased presence of antibiotics in surface water, likely from poultry sources as no other wastewater contributions in the area were documented

Novel IgG-degrading enzymes of the IgdE protease family link substrate specificity to host tropism of <i>Streptococcus</i> species

Recently we have discovered an IgG degrading enzyme of the endemic pig pathogen S. suis designated IgdE that is highly specific for porcine IgG. This protease is the founding member of a novel cysteine protease family assigned C113 in the MEROPS peptidase database. Bioinformatical analyses revealed putative members of the IgdE protease family in eight other Streptococcus species. The genes of the putative IgdE family proteases of S. agalactiae, S. porcinus, S. pseudoporcinus and S. equi subsp. zooepidemicus were cloned for production of recombinant protein into expression vectors. Recombinant proteins of all four IgdE family proteases were proteolytically active against IgG of the respective Streptococcus species hosts, but not against IgG from other tested species or other classes of immunoglobulins, thereby linking the substrate specificity to the known host tropism. The novel IgdE family proteases of S. agalactiae, S. pseudoporcinus and S. equi showed IgG subtype specificity, i.e. IgdE from S. agalactiae and S. pseudoporcinus cleaved human IgG1, while IgdE from S. equi was subtype specific for equine IgG7. Porcine IgG subtype specificities of the IgdE family proteases of S. porcinus and S. pseudoporcinus remain to be determined. Cleavage of porcine IgG by IgdE of S. pseudoporcinus is suggested to be an evolutionary remaining activity reflecting ancestry of the human pathogen to the porcine pathogen S. porcinus. The IgG subtype specificity of bacterial proteases indicates the special importance of these IgG subtypes in counteracting infection or colonization and opportunistic streptococci neutralize such antibodies through expression of IgdE family proteases as putative immune evasion factors. We suggest that IgdE family proteases might be valid vaccine targets against streptococci of both human and veterinary medical concerns and could also be of therapeutic as well as biotechnological use

Bacteremia Caused by Group G Streptococci, Taiwan

A retrospective observational study in Taiwan, 1998–2004, identified 92 patients with group G streptococcal bacteremia; 86 had Streptococcus dysgalactiae subspecies equisimilis. The most common diagnosis was cellulitis (48 cases), followed by primary bacteremia (34 cases). Infection recurred in 9 patients. Mortality rate was low (3.3%); resistance to quinupristin-dalfopristin was high

Der Einfluss der oralen Antidiabetika Metformin und Thiazolidindion auf die Hormonexpression humaner Trophoblastzellen

Die Therapie des Gestationsdiabetes besteht in einer Humaninsulintherapie, selten kommen orale Antidiabetika zum Einsatz. In dieser Arbeit wurde der Einfluss der oralen Antidiabetika Metformin und Thiazolidindion auf die Plazentafunktion anhand aus humanen Plazenten isolierten Trophoblastzellen untersucht. Für Thiazolidindion ergab sich eine erhöhte Zytotoxizität. Unter Metformin bestand eine Reduktion des Östrogens. Unter Thiazolidindion war eine signifikante Zunahme der Progesteronkonzentration nachweisbar. Zudem wurde für beide Medikamente eine Reduktion der PlGF-Konzentration beobachtet

Schwermetallimmobilisierung auf ehemaligen Rieselfeldern - Statuskontrolle 20 Jahren nach einer Sanierung

Das Abwasser von Berlin wurde über einen Zeitraum von 100 Jahren auf Rieselfeldern behandelt. Infolge dessen sind im Umland der Stadt großflächige Altlasten entstanden, von denen auch nach Einstellung der Berieselung erhebliche Gefahren für die Umwelt ausgehen. Auf den ehemaligen Rieselfeldern von Berlin-Buch im Norden der Stadt wurden vor 20 Jahren Maßnahmen durchgeführt, um das Gefährungspotenzial der Schadstoffe einzudämmen, den Bodenwasserhaushalt zu verbessern und eine Wiederaufforstung zu ermöglichen. Dazu wurde Geschiebemergel auf die Böden aufgebracht und teilweise eingearbeitet (HOFFMANN 2001). Der Vortrag betrachtet die aktuellen Resultate dieser Sanierungs- bzw. Sicherungsmaßnahmen hinsichtlich der Schwermetallkontamination. Es werden zwei mit unterschiedlichen Maßnahmen sanierte Flächen vorgestellt und mit einem unsanierten Standort verglichen. Dazu wurden bodenchemische und bodenphysikalisch Labormessungen sowie numerische Simulationen durchgeführt. An Hand der Effekte auf den Bodenwasserhaushalt und die Mobilität der Schwermetalle wird abschließend die Wirksamkeit der Maßnahmen bewertet

Einfluss von Biokohle auf Kennwerte der Wasserbindung im Boden

Zur Bestimmung des Einflusses von Biochar und Hydrochar auf den Wasserhaushalt wurden sandige Bodensubstrate (Ss und Sl2) mit unterschiedlichen Massenanteilen der genannten Kohlen vermengt. Es zeigte sich eine Steigerung der nutzbaren Feldkapazität durch die Applikation von Biochar und Hydrochar in Abhängigkeit der (i) Bodenart, des (ii) Humusgehalts der verwendeten Böden und der (iii) zugegebenen Menge an Kohle