Project description:Background. Pneumococcus is a major human pathogen and the polysaccharide capsule is considered its main virulence factor. Nevertheless, strains lacking a capsule, named non-typeable pneumococcus (NT), are maintained in nature and frequently colonise the human nasopharynx. Interest in these strains, not targeted by any of the currently available pneumococcal vaccines, has been rising as they seem to play an important role in the evolution of the species. Currently, there is a paucity of data regarding this group of pneumococci. Also, questions have been raised on whether they are true pneumococci. We aimed to obtain insights in the genetic content of NT and the mechanisms leading to non-typeability and to genetic diversity. Methods. A collection of 52 NT isolates representative of the lineages circulating in Portugal between 1997 and 2007, as determined by pulsed-field gel electrophoresis and multilocus sequence typing, was analysed. The capsular region was sequenced and comparative genomic hybridisation (CGH) using a microarray covering the genome of 10 pneumococcal strains was carried out. The presence of mobile elements was investigated as source of intraclonal variation. Results. NT circulating in Portugal were found to have similar capsular regions, of cps type NCC2, i.e., having aliB-like ORF1 and aliB-like ORF2 genes. The core genome of NT was essentially similar to that of encapsulated strains. Also, competence genes and most virulence genes were present. The few virulence genes absent in all NT were the capsular genes, type-I and type-II pili, choline-binding protein A (cbpA/pspC), and pneumococcal surface protein A (pspA). Intraclonal variation could not be entirely explained by the presence of prophages and other mobile elements. Conclusions. NT circulating in Portugal are a homogeneous group belonging to cps type NCC2. Our observations support the theory that they are bona-fide pneumococcal isolates that do not express the capsule but are otherwise essentially similar to encapsulated pneumococci. Thus we propose that NT should be routinely identified and reported in surveillance studies.
Project description:The pyrite mine of Lousal, Grândola, Portugal, was discovered in 1882 and extensively exploited from 1900 until its closure in 1988 when the mining ores were not viable economically. Aiming at becoming a cultural-touristic center, the mining area was rehabilitated raising a Mining Museum and a Science Centre along with the reopening of a mining gallery for public access. In recent times, aerobiological studies on subterranean environments such as caves, mines and archeological necropolis revealed to be an important source of novel bacteria, from which their biotechnological potential are under study. Here we present a Pseudomonas sp. isolated from the mine air with potential secondary metabolite biosynthesis, resistance to antibiotics and virulence factors.
Project description:C. coli is the predominant Campylobacter strain that is found in pigs while C. jejuni if present will be 10- 100 folds less. Natural transformation can occur if there is a coexistence of both the strains in the intestine of pigs. Genome analyses were performed on a C. jejuni strain U101 isolated from the upper intestine and two C. coli strains, C101 and L101 isolated from caecum and lower intestine.