Spectrum of pncA mutations in multidrug-resistant Mycobacterium tuberculosis isolates obtained in latvia [2]

Peer reviewe

Fibronectin-binding nanoparticles for intracellular targeting addressed by B. burgdorferi BBK32 protein fragments

Virus-like particles (VLPs) are created by the self-assembly of multiple copies of envelope and/or capsid proteins from many viruses, mimicking the conformation of a native virus. Such noninfectious nanostructures are mainly used as antigen-presenting platforms, especially in vaccine research; however, some of them recently were used as scaffolds in biotechnology to produce targeted nanoparticles for intracellular delivery. This study demonstrates the creation of fusion VLPs using hepatitis B core protein-based system maintaining a fibronectin-binding property from B. burgdorferi BBK32 protein, including the evidence of particles’ transmission to BHK-21 target cells via caveolae/rafts endocythosis. These results make this construct to be an attractive model in development of HBc-based nanoparticles for cellular targeting applications and highlights the fragment of B. burgdorferi BBK32 as a novel cellular uptake-promoting peptide.This work was supported by grant of Latvian Council of Science, Nr. 10.0029.3 and by ESF Projec

Identification of Three Clinically Relevant Borrelia burgdorferi Sensu Lato Genospecies by PCR-Restriction Fragment Length Polymorphism Analysis of 16S-23S Ribosomal DNA Spacer Amplicons

We report the results of a study of the prevalences of three clinically relevant Borrelia burgdorferi sensu lato genospecies (Borrelia burgdorferi sensu stricto, Borrelia afzelii, and Borrelia garinii) in 1,040 questing Ixodes ticks from all regions of Latvia, where Lyme borreliosis is endemic. The prevalences of Borrelia in Ixodes ricinus and Ixodes persulcatus were 22.6 and 27.9%, respectively. Molecular typing of B. burgdorferi from infected ticks was performed by restriction fragment length polymorphism (RFLP) analysis of PCR-amplified fragments of the 16S-23S (rrs-rrlA) rRNA intergenic spacer by using species-specific primers and subsequent sequencing. The dominant Borrelia species in both Ixodes species was B. afzelii. In addition, different restriction patterns of B. garinii and B. afzelii were also identified. This study demonstrates that the 16S-23S rRNA PCR-RFLP typing method is simple, sensitive, and fast and that it allows one to differentiate among B. burgdorferi species and subspecies with various degrees of pathogenic potential directly in ticks. These features are important in monitoring Lyme disease

The link between mitochondrial DNA hypervariable segment I heteroplasmy and ageing among genetically unrelated Latvians

Funding Information: This research was supported by a grant from the Latvian Council of Science National Programs no. 09.1284 and 10.0010.01 , and the European Social Fund project no. 1DP/1.1.2.0/09/APIA/VIAA/150 . We wish to express our gratitude to two anonymous reviewers for their helpful suggestions. We acknowledge Ligija Ignatovica for technical assistance in sequencing analysis and the administrators of the Genome Database of the Latvian Population, Latvian Biomedical Research and Study Centre.Various studies have demonstrated that mitochondrial DNA (mtDNA) heteroplasmy tends to increase with age and that the observed frequency of heteroplasmy among populations mostly depends on the way it is measured. Therefore, we investigated age-related association on the presence of mtDNA heteroplasmy within the hypervariable segment 1 (HVS-I) in a selected study group. The study group consisted of 300 maternally unrelated Latvians ranging in age from 18 to over 90. years. To determine the optimal method for mtDNA heteroplasmy detection, three approaches were used: (i) SURVEYOR Mutation Detection Kit, (ii) sequencing and (iii) denaturing gradient-gel electrophoresis (DGGE). Among the studied individuals, 30.3% were found to be heteroplasmic. The distribution of heteroplasmy statistically significantly increased with individuals' age (17%; 95% confidence interval [CI] 0.095-0.244 in the 18-40. year age group vs. 39%; [CI] 0.294-0.487 in the > 90 year age group). Heteroplasmy occurred in a total of 21 different positions within HVS-I, and was the most frequent at fast-mutated positions 16189, 16304 and 16311. The results indicate that heteroplasmy in HVS-I is relatively common and occurs in a broad spectrum of sites. The above is supported by evidence to eventual increase of the probability of heteroplasmy with age due to specific mitochondrial haplogroup background.publishersversionPeer reviewe

Prevalence of various Borrelia burgdorferi sensu lato Borrelia burgdorferi sensu lato Borrelia burgdorferi species in Ixodes ticks in three Baltic countries

Abstract Borrelia burgdorferi sensu lato, a tick-borne spirochete, is the causative agent of Lyme disease, the most prevalent vector-borne disease in Europe and United States. However, the incidence of this disease is variable and the clinical picture depends on the pathogen species. The infectivity of Ixodes ticks with Borrelia, was 46 % and 35 % in 2000 and 2001 in Latvia, respectively, and 14 % in 2002 in Lithuania, assessed by nested polymerase chain reaction (PCR) amplifi cation of the plasmid OspA gene fragment of Borrelia. PCR-restriction fragment length polymorphism (RFLP) analysis of the 16S-23S (rrs-rrlA) rRNA intergenic spacer was used for typing of Borrelia directly in ticks. Species-specifi c primers and subsequent sequences analysis were used as another approach for Borrelia species typing. All three clinically relevant B. burgdorferi sensu lato genospecies (B. afzelii, B. garinii, B. burgdorferi sensu stricto) were detected in the ticks collected in Latvia. The same result was obtained earlier in Estonia. B. valaisiana, a possible infectious agent of Lyme borreliosis, was detected only in Latvia. Only B. afzelii and B. garinii species were detected in ticks from Lithuania. Different subspecies were also identifi ed. This study demonstrates the predominance of the genospecies B. afzelii in all three Baltic countries, and the circulation of different B. burgdorferi sensu lato subspecies in the environment. This knowledge might have a signifi cant importance for monitoring of Lyme disease in Europe

Cilveka atrija natriuretiska faktora fiziologiski aktivas darbibas mehanismu petijumi un potencialo farmakopreparatu meklejumi

Annotation in EnglishAvailable from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELatvian Council of Science, Riga (Latvia)LVLatvi