One strategy to decrease the incidence of hospital-acquired infections is to avoid the survival of pathogens in the environment by the development of surfaces with antimicrobial activity. To study the antibacterial behaviour of active surfaces, different approaches have been developed of which ISO 22916 is the standard. To assess the performance of different testing methodologies to analyse the antibacterial activity of hydrophobic surface patterned plastics as part of a Horizon 2020 European research project. Four different testing methods were used to study the antibacterial activity of a patterned film, including the ISO 22916 standard, the immersion method, the touch-transfer inoculation method, and the swab inoculation method, this latter developed specifically for this project. The non-realistic test conditions of the ISO 22916 standard showed this method to be non-appropriate in the study of hydrophobic patterned surfaces. The immersion method also showed no differences between patterned films and smooth controls due to the lack of attachment of testing bacteria on both surfaces. The antibacterial activity of films could be demonstrated by the touch-transfer and the swab inoculation methods, that more precisely mimicked the way of high-touch surfaces contamination, and showed to be the best methodologies to test the antibacterial activity of patterned hydrophobic surfaces. A new ISO standard would be desirable as the reference method to study the antibacterial behaviour of patterned surfaces.
To analyse all cases of Nocardia pneumonia occurring between 2010 and 2016 in five Spanish hospitals. This was a retrospective observational analysis of clinical and microbiological data collected from 55 cases of Nocardia pneumonia. There were one to 20 cases per hospital and six to nine cases per year. Chronic obstructive pulmonary disease, bronchiectasis, and asthma were the main predisposing underlying respiratory conditions. Thirty-four patients were receiving systemic and/or inhaled corticosteroids prior to infection, eight had neoplasia, and six had haematological malignancies. Clinical and radiological findings were common to pneumonia of other infectious aetiologies, except for the frequent presence of nodules and cavitation. Overall, the 1-year mortality was high (38.2%), and mortality was directly related to the pulmonary disease in 15 patients (27.3%). The most frequently identified species were N. cyriacigeorgica (n=21), N. abscessus (n=8), and N. farcinica (n=5). All Nocardia isolates were susceptible to linezolid and all but two were susceptible to amikacin and trimethoprim-sulfamethoxazole. Nocardia pneumonia-associated mortality remains high, probably because of the debilitated status of patients in whom this pathogen is able to cause pulmonary infection.
Strains 335427T and 234509T, isolated from two 76-year-old patients with chronic pulmonary diseases, were the subject of polyphasic taxonomic studies and comparative genomic analyses for virulence factors. The 16 rRNA gene sequence similarity between strains 335427T and 234509T and their closest phylogenetic neighbors Nocardia asiatica NBRC 100129T and Nocardia abscessus NBRC 100374T were 99.5% and 100%, respectively. Digital DNA–DNA hybridization values between the aforementioned studied strains were well below the 70% threshold for assigning prokaryotic strains to a novel species. Strains 335427T and 234509T have genome sizes of 8.49 Mpb and 8.07 Mpb, respectively, with G + C content of 68.5%. Isolate 335427T has C16:0, C18:1 ω9c, C18:0 and C18:0 10 methyl as major fatty acids (>15%) and mycolic acids formed of 52–54 carbon atoms. However, only C18:1 ω9c was detected for isolate 234509T, which had mycolic acids with 44–56 carbon. Based on phenotypic and genetic data, strains 335427T (DSM 109819T = CECT 9924T) and 234509T (DSM 111366T = CECT 30129T) merit recognition as novel species, which are named Nocardia barduliensis sp. nov. and Nocardia gipuzkoensis sp. nov., respectively. All the strains studied had homologous VF-associated genes to those described in M. tuberculosis, including experimentally verified virulence genes in humans related to tuberculosis. The narGHIJ (nitrate reduction pathway) and gvpAFGOJLMK (gas vesicles) genetic maps of strains 335427T, 234509T, NBRC 100129T and NBRC 100374T showed the same syntenic block and raise the question of whether their functions are interlinked during the infection of the human host. However, further research is required to decipher the role of the gas vesicle in the pathogenicity mechanism of Nocardia spp.
One of the beneficial effects of pneumococcal conjugate vaccines (PCVs) has been a decrease in the incidence of non-invasive infections, such as otitis media (OM) caused by vaccine serotypes. In this study, we analyzed the epidemiology of pneumococcal OM before and after PCV13 introduction in 2010. Between 2008 and 2016, the middle ear exudates from 2653 children under 14 years of age with OM were studied in two Spanish provinces (Gipuzkoa and Barcelona), and S. pneumoniae was isolated in 235 (8.9%) of cases. The 204 available isolates were serotyped and distributed in three 3-year periods: one before and two after PCV13 introduction (early and late post-PCV13). A significant decrease in the rate of OM caused by S. pneumoniae was observed mainly due to a decrease in infections caused by all PCV13 serotypes, although exceptions were observed including the persistence of serotype 3 in Gipuzkoa and a weak re-emergence of serotype 19F in both regions. The rate and diversity of non-PCV13 serotypes increased in both regions and an emerging clone causing OM was detected in each region: serotype 23B ST2372 in Gipuzkoa and serotype 11A ST838/ST6521 in Barcelona. The introduction of PCV13 has been followed by a change in the epidemiology of pneumococcal OM, with a decrease in the rate of vaccine serotypes accompanied by an increase in the diversity of non-vaccine serotype and the clonal spreading of different single clones in each region.
Background The successful pneumococcal clone Spain9V-ST156 (PMEN3) is usually associated with vaccine serotypes 9V and 14. Aim Our objective was to analyse the increase of a serotype 11A variant of PMEN3 as cause of invasive pneumococcal disease (IPD) in Spain and its spread in south-western Europe. Methods We conducted a prospective multicentre study of adult IPD in Spain (2008–16). Furthermore, a subset of 61 penicillin-resistant serotype 11A isolates from France, Italy, Portugal and Spain were subjected to whole genome sequencing (WGS) and compared with 238 genomes from the European Nucleotide Archive (ENA). Results Although the incidence of serotype 11A in IPD was stable, a clonal shift was detected from CC62 (penicillin-susceptible) to CC156 (penicillin-resistant). By WGS, three major 11A-CC156 lineages were identified, linked to ST156 (n = 5 isolates; France, Italy and Portugal), ST166 (n = 4 isolates; France and Portugal) and ST838/6521 (n = 52 isolates; France, Portugal and Spain). Acquisition of the 11A capsule allowed to escape vaccine effect. AP200 (11A-ST62) was the donor for ST156 and ST838/6521 but not for ST166. In-depth analysis of ST838/6521 lineage showed two multi-fragment recombination events including four and seven fragments from an 11A-ST62 and an NT-ST344 representative, respectively. Conclusion The increase in penicillin-resistant serotype 11A IPD in Spain was linked to the spread of a vaccine escape PMEN3 recombinant clone. Several recombination events were observed in PMEN3 acquiring an 11A capsule. The most successful 11A-PMEN3 lineage spreading in south-western Europe appeared after two multi-fragment recombination events with representatives of two major pneumococcal clones (11A-ST62 and NT-ST344).