OBJECTIVE: To determine the nature (clonal type and antibiotic resistance pattern) of methicillin-resistant Staphylococcus aureus (MRSA) strains recovered from the largest teaching hospital in Portugal and to detect temporal trends in clonal types during three consecutive surveillance periods in 1992--93, 1994--95 and 1996. METHODS: MRSA strains were characterized by chromosomal SmaI macrorestriction patterns using pulsed-field gel electrophoresis (PFGE) and by DNA fingerprints---applied to ClaI digests---capable of probing two specific areas of the staphylococcal chromosome: (1) the vicinity of the mecA gene, and (2) the attachment site(s) and copy number of transposon Tn554. The combination of these methods can generate 'clonal types' useful for epidemiological tracking of MRSA strains. RESULTS: During the 1992--93 collection period, 65% of MRSA strains carried the mecA polymorph I, Tn554 pattern E and PFGE pattern A (I::E::A)---a clonal type that was used to define the 'Iberian MRSA', which is widely spread throughout southern Europe. The representation of this clone decreased to 42% in 1994--95 and to 20% in 1996. At the same time, a second multiresistant MRSA strain carrying mecA polymorph XI, Tn554 type B and PFGE pattern B (XI::B::B)---a clonal type characteristic of the so-called 'Brazilian MRSA'---increased from 5% in 1992--93 to 36% in 1994--95 and 29% in 1996. CONCLUSIONS: Throughout the four years of surveillance, the Iberian and Brazilian MRSA types and their single subtype variants together have been responsible for the overwhelming majority (close to 90%) of all MRSA infections in the largest teaching hospital of Portugal. The mechanism of epidemicity of these two multiresistant international MRSA clones remains to be elucidated.

Marine-derived actinomycetes have demonstrated an ability to produce novel compounds with medically relevant biological activity. Studying the diversity and biogeographical patterns of marine actinomycetes offers an opportunity to identify genera that are under environmental pressures, which may drive adaptations that yield specific biosynthetic capabilities. The present study describes research efforts to explore regions of the Atlantic Ocean, specifically around the Madeira Archipelago, where knowledge of the indigenous actinomycete diversity is scarce. A total of 400 actinomycetes were isolated, sequenced, and screened for antimicrobial and anticancer activities. The three most abundant genera identified were Streptomyces, Actinomadura, and Micromonospora. Phylogenetic analyses of the marine OTUs isolated indicated that the Madeira Archipelago is a new source of actinomycetes adapted to life in the ocean. Phylogenetic differences between offshore (>100 m from shore) and nearshore (< 100 m from shore) populations illustrates the importance of sampling offshore in order to isolate new and diverse bacterial strains. Novel phylotypes from chemically rich marine actinomycete groups like MAR4 and the genus Salinispora were isolated. Anticancer and antimicrobial assays identified Streptomyces, Micromonospora, and Salinispora as the most biologically active genera. This study illustrates the importance of bioprospecting efforts at unexplored regions of the ocean to recover bacterial strains with the potential to produce novel and interesting chemistry.

This study presents the serotype distribution and the antibiotic resistance profile of 953 colonising group B Streptococcus (GBS) recovered from women of child bearing age (15 to 49 years) between 2005 and 2012 in the Lisbon and Tagus Valley region, Portugal. Overall, serotypes Ia, II, III, and V were the most common, accounting 752 of the 953 isolates (about 80%). However, there were changes in GBS distribution, in particular in the two last years of the study. Of note, the proportion of serotype IV isolates increased from 1% (2/148) in 2006 to 20% (19/97) in 2012. Also, considerable proportions of serotype IV isolates from 2010 to 2012 were respectively resistant to erythromycin (9/43; 21%) or clindamycin (6/43; 14%). The identification of nine serotype IV isolates presenting a novel association with the clonal complex (CC) 17 lineage, involving a putative capsular switch, may accentuate their virulence potential and ecological success. Molecular analysis of this subgroup of isolates revealed the presence of rib, IS (insertion sequence) 861 and GBSi1 group II intron within the C5a peptidase gene (scpB) -laminin-binding protein gene (lmb) region, reflecting high clonality and a putative common origin. A close surveillance of the emergent type IV/CC17 isolates is crucial considering the potential impact over GBS treatment guidelines and capsular vaccine development.

No abstract