Proteolytic Enzymes of Vegetative Forms and Spores of the Bacterium Paenibacillus larvae

Due to the high resistance of the spores, the bacterium Paenibacillus larvae is the most dangerous bacterial pathogen of the honey bee (Apis mellifera). Thanks to its biological properties and restricted pathogenicity, this bacterium can be used as a model organism to study gram positive sporulating aerobic rods. This work is focused on completing information about secreted proteases of this bacterium and in a study of proteases bound in a spore structure. MYPGP medium was used for the cultivation of P. larvae. In this medium, lysis of the culture was shown after 40 hours of cultivation. The pH of the medium decreased below 6.4 by lysis. The induction of temperate bacteriophage BLA was detected as a causative agent of this lysis. A new sporulation medium called HCBB agar was proposed for the sporulation of P. larvae. In comparison with HCBB agar with MYPGP agar by 31 strains of P. larvae stored in our collection, HCBB agar was evaluated as an appropriate sporulation medium with a median of sporulatin 4.2 ' 106 spores per cm2 in aerobic conditions and 5.65 ' 106 spores per cm2 in aerobic conditions with 10 % CO2. For purification of the secreted proteases, a one-day culture incubated at room temperature was used. Optimal purification of 87/74 kDa and 42/40 kDa proteases was observed after application of this..

Biochemical Characterization of VIM-39, a VIM-1-Like Metallo-β-Lactamase Variant from a Multidrug-Resistant Klebsiella pneumoniae Isolate from Greece

VIM-39, a VIM-1-like metallo-β-lactamase variant (VIM-1 Thr33Ala His224Leu) was identified in a clinical isolate of Klebsiella pneumoniae belonging to sequence type 147. VIM-39 hydrolyzed ampicillin, cephalothin, and imipenem more efficiently than did VIM-1 and VIM-26 (a VIM-1 variant with the His224Leu substitution) because of higher turnover rates

A novel nonsense mutation in the β-subunit of the epithelial sodium channel causing Liddle syndrome

Purpose Liddle syndrome is a hereditary form of arterial hypertension caused by mutations in the genes coding of the epithelial sodium channel – SCNN1A, SCNN1B and SCNN1G. It is characterised by early onset of hypertension and variable biochemical features such as hypokalaemia and low plasma concentrations of renin and aldosterone. Phenotypic variability is large and, therefore, LS is probably underdiagnosed. Our objective was to examine a family suspected from Liddle syndrome including genetic testing and evaluate clinical and biochemical features of affected family members. Materials and methods Thirteen probands from the Czech family, related by blood, underwent physical examination, laboratory tests, and genetic testing. Alleles of SCNN1B and SCNN1G genes were examined by PCR amplification and Sanger sequencing of amplicons. Results We identified a novel mutation in the β-subunit of an epithelial sodium channel coded by the SCNN1B gene, causing the nonsense mutation in the protein sequence p.Tyr604*. This mutation was detected in 7 members of the family. The mutation carriers differed in the severity of hypertension and hypokalaemia which appeared only after diuretics in most of them; low aldosterone level (< 0.12 nmol/l) was, however, present in all. Conclusions This finding expands the spectrum of known mutations causing Liddle syndrome. Hypoaldosteronemia was 100% sensitive sign in the mutation carriers. Low levels are observed especially in the Caucasian population reaching 96% sensitivity. Assessment of plasma aldosterone concentration is helpful for differential diagnosis of arterial hypertension. CONDENSED ABSTRACT Liddle syndrome is a hereditary form of arterial hypertension caused by mutations in the genes encoding the epithelial sodium channel’s α-, β- and γ-subunit. It is usually manifested by early onset of hypertension accompanied by low potassium and aldosterone levels. We performed a physical examination, laboratory tests and genetic screening in 13 members of a Czech family. We found a new mutation of the SCNN1B gene which encodes the β-subunit of the epithelial sodium channel. We describe the variability of each family member phenotype and point out the relevance of using aldosterone levels as a high sensitivity marker of Liddle syndrome in Caucasians