title: Characterization of Streptococcus pneumoniae clones from paediatric patients with cystic fibrosis.
abstract: The role of Streptococcus pneumoniae in cystic fibrosis (CF) is poorly understood. The pneumococcal population has changed over time after the introduction of the heptavalent conjugate vaccine (PCV7) and, more recently, the 13-valent conjugate vaccine (PCV13). Although serotypes and clones causing invasive pneumococcal disease or colonizing healthy children have been extensively analysed, little is known so far on the serotypes and clones of pneumococci in CF patients. The aim of this work was to investigate serotypes, antibiotic susceptibilities, genotypes and biofilm production of CF pneumococcal isolates. Overall, 44 S. pneumoniae strains collected from 32 paediatric CF patients from January 2010 to May 2012 in a large Italian CF Centre were tested for antimicrobial susceptibility testing by Etest, serotyped by the Quellung reaction and genotyped by a combination of different molecular typing methods, including pbp gene restriction profiling, pspA restriction profiling and sequencing, PFGE and multilocus sequence typing. Biofilm production by pneumococcal strains was also assessed. Penicillin non-susceptibility was 16 %. High resistance rates (>56 %) were observed for erythromycin, clindamycin and tetracycline. The most frequent serotype recovered was serotype 3 (31.8 %). The coverage of PCV7 and PCV13 was 6.8 and 47.7 %, respectively. More than 80 % of CF strains belonged to Pneumococcal Molecular Epidemiology Network (PMEN) reference clones, the most common being Netherlands(3)-ST180 (28.2 %), and Greece(21)-30/ST193 (15.4 %). All strains produced biofilm in vitro, although with large variability in biofilm formation efficiency. No correlation was found between biofilm levels and serotype, clone or antibiotic resistance. The high isolation rate of antibiotic-resistant serotype 3 pneumococci from CF patients suggests that PCV13 could increase protection from pneumococcal colonization and infection.
authors.affiliation: Integrated Research Centre (CIR), University Campus Biomedico, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Pimentel de Araujo
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: D'Ambrosio
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Romina
authors.initials: R
authors.lastname: Camilli
authors.affiliation: Cystic Fibrosis Microbiology, Children's Hospital and Research Institute 'Bambino Gesù', Piazza S. Onofrio 4, 00165 Rome, Italy.
authors.forename: Ersilia
authors.initials: E
authors.lastname: Fiscarelli
authors.affiliation: Center of Excellence on Aging, 'G. D'Annunzio' University Foundation, Via Colle dell'Ara, 66100 Chieti, Italy.|Department of Experimental and Clinical Sciences, 'G. D'Annunzio' University of Chieti-Pescara, Via Vestini 31, 66100 Chieti, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Bonaventura
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Lucilla
authors.initials: L
authors.lastname: Baldassarri
authors.affiliation: Department of Sciences, Roma Tre University, Viale Marconi 446, 00146 Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Visca
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Pantosti
authors.affiliation: Integrated Research Centre (CIR), University Campus Biomedico, Via Alvaro del Portillo 200, 00128 Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gherardi
mesh_terms: D000293:Adolescent; D018441:Biofilms / Q000254:growth & development; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000150:complications*; D024881:Drug Resistance, Bacterial; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007558:Italy; D008297:Male; D058889:Molecular Typing; D011008:Pneumococcal Infections / Q000382:microbiology*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology