RESUMEN
The aim of this study was to determine the potential application of N-chlorotaurine (NCT), N,N-dichloro-2,2-dimethyltaurine (NVC-422), and N-monochloro-2,2-dimethyltaurine (NVC-612) as catheter lock solutions for the prevention of catheter blockage and catheter-related bloodstream infections by testing their anticoagulant and broad-spectrum antimicrobial activities in human blood. NCT, NVC-422, NVC-612, and control compounds were serially diluted in fresh human blood to evaluate the effects on prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, and direct thrombin inhibition. Quantitative killing assays against pathogens, including methicillin-resistant Staphylococcus aureus, Escherichia coli, and Candida albicans, were performed in the presence of heparin and human blood. NCT and NVC-612 (1.38 mM each) and 1.02 mM NVC-422 prolonged prothrombin time (Quick value, 17 to 30%), activated partial thromboplastin time 3- to 4-fold to 76 to 125 s, and thrombin time 2- to 4-fold to 34 to 68 s. Fibrinogen decreased from 258 to 283 mg/dl (range of controls) to <40 mg/dl. No direct thrombin inhibition was observed by NVC-422 or NVC-612. Heparin did not influence the bactericidal activity of NCT. The microbicidal activities of NCT, NVC-422, and NVC-612 were maintained in diluted human blood. NCT, NVC-612, and NVC-422 have broad-spectrum antimicrobial activity in blood and anticoagulant activity targeting both intrinsic and extrinsic pathways of the coagulation system. These properties support their application as catheter lock solutions.
Asunto(s)
Antibacterianos/sangre , Antibacterianos/farmacología , Anticoagulantes/sangre , Anticoagulantes/farmacología , Antifúngicos/sangre , Antifúngicos/farmacología , Taurina/análogos & derivados , Coagulación Sanguínea/efectos de los fármacos , Pruebas de Coagulación Sanguínea , Tampones (Química) , Candida albicans/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Heparina/farmacología , Humanos , Técnicas In Vitro , Relación Normalizada Internacional , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Soluciones , Taurina/sangre , Taurina/farmacología , Trombina/antagonistas & inhibidoresRESUMEN
Erwinia herbicola pv. gypsophilae induces gall formation in gypsophila that is dependent on the existence of a pathogenicity plasmid (pPATHEhg). We previously demonstrated the presence of several hrp genes on this plasmid. By employing transposon mutagenesis and sequencing, a functional hrp gene cluster on the pPATHEhg has now been characterized completely. The hrp genes of E. herbicola pv. gypsophilae are remarkably similar to and colinear with those of Erwinia amylovora and Pantoea stewartii and generally showed 60 to 90% nucleotide or deduced amino acid identity. E. herbicola pv. gypsophilae, however, lacks hrpW, which is present in E. amylovora. Additionally, E. herbicola pv. gypsophilae mutants deficient in harpin production retained pathogenicity and were slightly reduced in their ability to elicit a hypersensitive response (HR) in tobacco. The "disease specific" region, dspA/EB/F, exhibited 60 to 74% identity with the dspA/EB/F loci of E. amylovora and P. stewartii, respectively. Mutations in dspA/E abolished pathogenicity of E. herbicola pv. gypsophilae but not HR elicitation on tobacco. Inactivation of HrpL reduced plant-induced transcription of dspA/E by three orders, indicating Hrp-dependent regulation.