Swedish Institute

About: Swedish Institute is a government organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Population & Health care. The organization has 1657 authors who have published 2301 publications receiving 103682 citations. The organization is also known as: Svenska Institutet.

Characterization of a pore-forming cytotoxin expressed by Salmonella enterica serovars typhi and paratyphi A.

Abstract: Cytolysin A (ClyA) is a pore-forming cytotoxic protein encoded by the clyA gene that has been characterized so far only in Escherichia coli. Using DNA sequence analysis and PCR, we established that clyA is conserved in the human-specific typhoid Salmonella enterica serovars Typhi and Paratyphi A and that the entire clyA gene locus is absent in many other S. enterica serovars, including Typhimurium. The gene products, designated ClyASTy and ClyASPa, show ≥90% amino acid identity to E. coli cytolysin A, ClyAEC, and they are immunogenically related. The Salmonella proteins showed a pore-forming activity and are hence functional homologues to ClyAEC. The chromosomal clyASTy gene locus was expressed at detectable levels in the serovar Typhi strains S2369/96 and S1112/97. Furthermore, in the serovar Typhi vaccine strain Ty21a, expression of clyASTy reached phenotypic levels, as detected on blood agar plates. The hemolytic phenotype was abolished by the introduction of an in-frame deletion in the clyASTy chromosomal locus of Ty21a. Transcomplementation of the mutant with a cloned clyASTy gene restored the hemolytic phenotype. To our knowledge, Ty21a is the first reported phenotypically hemolytic Salmonella strain in which the genetic determinant has been identified.

Hearing help-seeking and rehabilitation: Perspectives of adults with hearing impairment

Abstract: OBJECTIVE:This study investigated the perspectives of adults with hearing impairment on hearing help-seeking and rehabilitationDESIGN:Individual semi-structured interviews were completedSTUDY SAMPLE:In total, 34 adults with hearing impairment in four countries (Australia, Denmark, UK, and USA) participated Participants had a range of experience with hearing help-seeking and rehabilitation, from never having sought help to being satisfied hearing-aid usersRESULTS:Qualitative content analysis identified four main categories ('perceiving my hearing impairment', 'seeking hearing help', 'using my hearing aids', and 'perspectives and knowledge') and, at the next level, 25 categories This article reports on the densest categories: they are described, exemplified with interview quotes, and discussedCONCLUSIONS:People largely described hearing help-seeking and rehabilitation in the context of their daily lives Adults with hearing impairment rarely described clinical encounters towards hearing help-seeking and rehabilitation as a connected process They portrayed interactions with clinicians as isolated events rather than chronologically-ordered steps relating to a common goal Clinical implications of the findings are discussed

Origin and Evolution of European Community-Acquired Methicillin-Resistant Staphylococcus aureus

Abstract: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized in Europe and worldwide in the late 1990s. Within a decade, several genetically and geographically distinct CA-MRSA lineages carrying the small SCC mec type IV and V genetic elements and the Panton-Valentine leukocidin (PVL) emerged around the world. In Europe, the predominant CA-MRSA strain belongs to clonal complex 80 (CC80) and is resistant to kanamycin/amikacin and fusidic acid. CC80 was first reported in 1993 but was relatively rare until the late 1990s. It has since been identified throughout North Africa, the Middle East, and Europe, with recent sporadic reports in sub-Saharan Africa. While strongly associated with skin and soft tissue infections, it is rarely found among asymptomatic carriers. Methicillin-sensitive S. aureus (MSSA) CC80 strains are extremely rare except in sub-Saharan Africa. In the current study, we applied whole-genome sequencing to a global collection of both MSSA and MRSA CC80 isolates. Phylogenetic analyses strongly suggest that the European epidemic CA-MRSA lineage is derived from a PVL-positive MSSA ancestor from sub-Saharan Africa. Moreover, the tree topology suggests a single acquisition of both the SCC mec element and a plasmid encoding the fusidic acid resistance determinant. Four canonical SNPs distinguish the derived CA-MRSA lineage and include a nonsynonymous mutation in accessory gene regulator C ( agrC ). These changes were associated with a star-like expansion into Europe, the Middle East, and North Africa in the early 1990s, including multiple cases of cross-continent imports likely driven by human migrations. IMPORTANCE With increasing levels of CA-MRSA reported from most parts of the Western world, there is a great interest in understanding the origin and factors associated with the emergence of these epidemic lineages. To trace the origin, evolution, and dissemination pattern of the European CA-MRSA clone (CC80), we sequenced a global collection of strains of the S. aureus CC80 lineage. Our study determined that a single descendant of a PVL-positive methicillin-sensitive ancestor circulating in sub-Saharan Africa rose to become the dominant CA-MRSA clone in Europe, the Middle East, and North Africa. In the transition from a methicillin-susceptible lineage to a successful CA-MRSA clone, it simultaneously became resistant to fusidic acid, a widely used antibiotic for skin and soft tissue infections, thus demonstrating the importance of antibiotic selection in the success of this clone. This finding furthermore highlights the significance of horizontal gene acquisitions and underscores the combined importance of these factors for the success of CA-MRSA.