1. Int J Antimicrob Agents. 2014 Jul 7. pii: S0924-8579(14)00182-4. doi:
10.1016/j.ijantimicag.2014.05.016. [Epub ahead of print]

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.

Vandevelde NM(1), Tulkens PM(2), Diaz Iglesias Y(1), Verhaegen J(3),
Rodriguez-Villalobos H(4), Philippart I(5), Cadrobbi J(6), Coppens N(7), Boel
A(8), Van Vaerenbergh K(8), Francart H(9), Vanhoof R(10), Liistro G(11), Jordens 
P(12), d'Odemont JP(13), Valcke Y(14), Verschuren F(15), Van Bambeke F(1).

Author information: 
(1)Pharmacologie cellulaire et moléculaire & Centre de Pharmacie Clinique, Louvain
Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
(2)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.
(3)Laboratorium microbiologie, Universitair Ziekenhuis Gasthuisberg, Leuven,
Belgium.
(4)Laboratoire de microbiologie, Cliniques universitaires St Luc, Brussels, Belgium.
(5)Laboratoire de microbiologie, Centre hospitalier régional Mons-Warquignies,
Warquignies, Belgium.
(6)Laboratoire de microbiologie, Clinique et Maternité Ste Elisabeth, Namur,
Belgium.
(7)Service de pneumologie, Clinique et Maternité Ste Elisabeth, Namur, Belgium.
(8)Laboratorium microbiologie, Onze Lieve Vrouw Ziekenhuis, Aalst, Belgium.
(9)Laboratorium microbiologie, Algemeen Ziekenhuis Nikolaas, St Niklaas, Belgium.
(10)Institut Scientifique de Santé Publique, Brussels, Belgium.
(11)Service de pneumologie, Cliniques universitaires St Luc, Brussels, Belgium.
(12)Pneumologie, Onze Lieve Vrouw Ziekenhuis, Aalst, Belgium.
(13)Service de pneumologie, Centre hospitalier régional Mons-Warquignies,
Warquignies, Belgium.
(14)Longziekten en allergieën, Algemeen Ziekenhuis Nikolaas, St Niklaas, Belgium.
(15)Service des Urgences, Cliniques universitaires Saint-Luc, Brussels, Belgium.

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.

Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All
rights reserved.

PMID: 25123808  [PubMed - as supplied by publisher]