title: Characterisation of a collection of Streptococcus pneumoniae isolates from patients suffering from acute exacerbations of chronic bronchitis: in vitro susceptibility to antibiotics and biofilm formation in relation to antibiotic efflux and serotypes/serogroups.
abstract: The correlation between Streptococcus pneumoniae serotypes, biofilm production, antibiotic susceptibility and drug efflux in isolates from patients suffering from acute exacerbations of chronic bronchitis (AECB) remains largely unexplored. Using 101 isolates collected from AECB patients for whom partial (n=51) or full (n=50) medical details were available, we determined serotypes (ST)/serogroups (SG) (Quellung reaction), antibiotic susceptibility patterns [MIC (microdilution) using EUCAST and CLSI criteria] and ability to produce biofilm in vitro (10-day model; crystal violet staining). The majority of patients were 55-75 years old and <5% were vaccinated against S. pneumoniae. Moreover, 54% showed high severity scores (GOLD 3-4), and comorbidities were frequent including hypertension (60%), cancer (24%) and diabetes (20%). Alcohol and/or tobacco dependence was >30%. Isolates of SG6-11-15-23, known for large biofilm production and causing chronic infections, were the most prevalent (>15% each), but other isolates also produced biofilm (SG9-18-22-27 and ST8-20 being most productive), except SG7, SG29 and ST5 (<2% of isolates each). Resistance (EUCAST breakpoints) was 8-13% for amoxicillin and cefuroxime, 35-39% for macrolides, 2-8% for fluoroquinolones and 2% for telithromycin. ST19A isolates showed resistance to all antibiotics, ST14 to all except moxifloxacin, and SG9 and SG19 to all except telithromycin, moxifloxacin and ceftriaxone (SG19 only). Solithromycin and telithromycin MICs were similar. No correlation was observed between biofilm production and MIC or efflux (macrolides, fluoroquinolones). S. pneumoniae serotyping may improve AECB treatment by avoiding antibiotics with predictable low activity, but it is not predictive of biofilm production.
authors.affiliation: Pharmacologie cellulaire et moléculaire & Centre de Pharmacie Clinique, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Nathalie M
authors.initials: NM
authors.lastname: Vandevelde
authors.affiliation: Pharmacologie cellulaire et moléculaire & Centre de Pharmacie Clinique, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium. Electronic address: tulkens@facm.ucl.ac.be.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Tulkens
authors.affiliation: Pharmacologie cellulaire et moléculaire & Centre de Pharmacie Clinique, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Diaz Iglesias
authors.affiliation: Laboratorium microbiologie, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Verhaegen
authors.affiliation: Laboratoire de microbiologie, Cliniques universitaires St Luc, Brussels, Belgium.
authors.forename: Hector
authors.initials: H
authors.lastname: Rodriguez-Villalobos
authors.affiliation: Laboratoire de microbiologie, Centre hospitalier régional Mons-Warquignies, Warquignies, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Philippart
authors.affiliation: Laboratoire de microbiologie, Clinique et Maternité Ste Elisabeth, Namur, Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Cadrobbi
authors.affiliation: Service de pneumologie, Clinique et Maternité Ste Elisabeth, Namur, Belgium.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Coppens
authors.affiliation: Laboratorium microbiologie, Onze Lieve Vrouw Ziekenhuis, Aalst, Belgium.
authors.forename: An
authors.initials: A
authors.lastname: Boel
authors.affiliation: Laboratorium microbiologie, Onze Lieve Vrouw Ziekenhuis, Aalst, Belgium.
authors.forename: Kristien
authors.initials: K
authors.lastname: Van Vaerenbergh
authors.affiliation: Laboratorium microbiologie, Algemeen Ziekenhuis Nikolaas, St Niklaas, Belgium.
authors.forename: Hugo
authors.initials: H
authors.lastname: Francart
authors.affiliation: Institut Scientifique de Santé Publique, Brussels, Belgium.
authors.forename: Raymond
authors.initials: R
authors.lastname: Vanhoof
authors.affiliation: Service de pneumologie, Cliniques universitaires St Luc, Brussels, Belgium.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Liistro
authors.affiliation: Pneumologie, Onze Lieve Vrouw Ziekenhuis, Aalst, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: Jordens
authors.affiliation: Service de pneumologie, Centre hospitalier régional Mons-Warquignies, Warquignies, Belgium.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: d'Odemont
authors.affiliation: Longziekten en allergieën, Algemeen Ziekenhuis Nikolaas, St Niklaas, Belgium.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Valcke
authors.affiliation: Service des Urgences, Cliniques universitaires Saint-Luc, Brussels, Belgium.
authors.forename: Franck
authors.initials: F
authors.lastname: Verschuren
authors.affiliation: Pharmacologie cellulaire et moléculaire & Centre de Pharmacie Clinique, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Françoise
authors.initials: F
authors.lastname: Van Bambeke
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D001693:Biological Transport, Active; D029481:Bronchitis, Chronic / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000382:microbiology*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Acute exacerbations of chronic bronchitis (AECB); Biofilm; Efflux; Serotype; Streptococcus pneumoniae; Susceptibility