Person: Domenech Lucas, Miriam
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First Name
Miriam
Last Name
Domenech Lucas
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Biológicas
Department
Genética, Fisiología y Microbiología
Area
Microbiología
Identifiers
3 results
Search Results
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Item A national longitudinal study evaluating the activity of cefditoren and other antibiotics against non-susceptible Streptococcus pneumoniae strains during the period 2004–20 in Spain(Journal of Antimicrobial Chemotherapy, 2022) Sempere, Julio; González-Camacho, Fernando; Domenech Lucas, Miriam; Llamosí, Mirella; Del Río, Idoia; López-Ruiz, Beatriz; Gimeno, Mercedes; Coronel, Pilar; Yuste, JoséBackground Surveillance studies including antibiotic resistance and evolution of pneumococcal serotypes are critical to evaluate the susceptibility of commonly used antibiotics and the contribution of conjugate vaccines against resistant strains. Objectives To determine the susceptibility of clinical isolates of Streptococcus pneumoniae with reduced susceptibility to penicillin to a panel of antibiotics during the period 2004–20 and characterize the impact of pneumococcal conjugate vaccines in the evolution of resistant serotypes. Methods We selected 3017 clinical isolates in order to determine the minimal inhibitory concentration to penicillin, amoxicillin, cefotaxime, erythromycin, levofloxacin and oral cephalosporins, including cefditoren, cefixime and cefpodoxime. Results The antibiotics with the lowest proportion of resistant strains from 2004 to 2020 were cefditoren (<0.4%), followed by cefotaxime (<5%), penicillin (<6.5%) and levofloxacin (<7%). Among oral cephalosporins, cefixime was the cephalosporin with the highest MIC90 (32 mg/L) and MIC50 (8–16 mg/L) throughout the study, followed by cefpodoxime with highest values of MIC90 (4 mg/L) and MIC50 (2 mg/L) for the majority of the study period. In contrast, cefditoren was the cephalosporin with the lowest MIC90 (1 mg/L) and MIC50 (0.25–0.5 mg/L). Conclusions Cefditoren was the antibiotic with the highest proportion of susceptible strains. Hence, more than 80% of the clinical strains were susceptible to cefditoren throughout the period 2004–20. The proportion of resistant isolates to cefditoren and cefotaxime was scarce, being less than 0.4% for cefditoren and lower than 5% for cefotaxime, despite the increased rates of serotypes not covered by the 13-valent pneumococcal conjugate vaccine.Item Nationwide Trends of Invasive Pneumococcal Disease in Spain From 2009 Through 2019 in Children and Adults During the Pneumococcal Conjugate Vaccine Era(Clinical Infectious Diseases, 2020) Miguel, Sara de; González-Camacho, Fernando; Domenech Lucas, Miriam; Sempere, Julio; Vicioso, Dolores; Sanz, Juan Carlos; García Comas, Luis; Ardanuy, Carmen; Fenoll, Asunción; Yuste, JoséBackground: Introduction of pneumococcal conjugate vaccines (PCVs) has reduced the disease caused by vaccine serotypes in children, providing herd protection to adults. However, the emergence of nonvaccine serotypes is of great concern worldwide. Methods: This study includes national laboratory data from invasive pneumococcal disease (IPD) cases that affected pediatric and adult populations during 2009–2019. The impact of implementing different vaccine strategies for immunocompetent adults by comparing Spanish regions that used the 13-valent PCV (PCV13) vs regions that used the 23-valent pneumococcal polysaccharide vaccine (PPV23) was also analyzed for 2017−2019. Results: The overall reductions in IPD cases by PCV13 serotypes in children and adults were 88% and 59%, respectively, during 2009–2019, with a constant increase in serotype 8 in adults since 2015. IPD cases by additional serotypes covered by PPV23 increased from 20% in 2009 to 52% in 2019. In children, serotype 24F was the most frequent in 2019, whereas serotypes 3 and 8 accounted for 36% of IPD cases in adults. Introduction of PCV13 or PPV23 in the adult calendar of certain Spanish regions reduced the IPD cases by PCV13 serotypes by up to 25% and 11%, respectively, showing a decrease of serotype 3 when PCV13 was used. Conclusions: Use of PCV13 in children has affected the epidemiology, reducing the burden of IPD in children but also in adults by herd protection; however, the increase in serotype 8 in adults is worrisome. Vaccination with PCV13 in adults seems to control IPD cases by PCV13 serotypes including serotype 3.Item Clinical Relevance and Molecular Pathogenesis of the Emerging Serotypes 22F and 33F of Streptococcus pneumoniae in Spain(Frontiers in Microbiology, 2020) Sempere, Julio; Miguel, Sara de; González-Camacho, Fernando; Yuste, José; Domenech Lucas, MiriamStreptococcus pneumoniae is the main bacterial cause of respiratory infections in children and the elderly worldwide. Serotype replacement is a frequent phenomenon after the introduction of conjugated vaccines, with emerging serotypes 22F and 33F as frequent non-PCV13 serotypes in children and adults in North America and other countries. Characterization of mechanisms involved in evasion of the host immune response by these serotypes is of great importance in public health because they are included in the future conjugated vaccines PCV15 and PCV20. One of the main strategies of S. pneumoniae to persistently colonize and causes infection is biofilm formation. In this study, we have evaluated the influence of capsule polysaccharide in biofilm formation and immune evasion by using clinical isolates from different sources and isogenic strains with capsules from prevalent serotypes. Since the introduction of PCV13 in Spain in the year 2010, isolates of serotypes 22F and 33F are rising among risk populations. The predominant circulating genotypes are ST43322F and ST71733F, being CC433 in 22F and CC717 in 33F the main clonal complexes in Spain. The use of clinical isolates of different origin, demonstrated that pediatric isolates of serotypes 22F and 33F formed better biofilms than adult isolates and this was statistically significant. This phenotype was greater in clinical isolates from blood origin compared to those from cerebrospinal fluid, pleural fluid and otitis. Opsonophagocytosis assays showed that serotype 22F and 33F were recognized by the PSGL-1 receptor on leukocytes, although serotype 22F, was more resistant than serotype 33F to phagocytosis killing and more lethal in a mouse sepsis model. Overall, the emergence of additional PCV15 serotypes, especially 22F, could be associated to an enhanced ability to divert the host immune response that markedly increased in a biofilm state. Our findings demonstrate that pediatric isolates of 22F and 33F, that form better biofilm than isolates from adults, could have an advantage to colonize the nasopharynx of children and therefore, be important in carriage and subsequent dissemination to the elderly. The increased ability of serotype 22F to avoid the host immune response, might explain the emergence of this serotype in the last years.