title: Impairment of respiratory burst in polymorphonuclear leukocytes by extended-spectrum beta-lactamase-producing strains of Klebsiella pneumoniae.
abstract: The ability of extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing Klebsiella pneumoniae strains to induce a respiratory burst in polymorphonuclear leukocytes (PMNLs) was investigated. Ninety ESBL-producing and 178 non-ESBL-producing Klebsiella pneumoniae isolates were serotyped and their ability to induce a respiratory burst in PMNLs tested by monitoring the cells' chemiluminescence (CL) response. The percentage of isolates inducing high levels of CL response (CL>75%) was significantly higher among non-ESBL producers (52%) than among ESBL producers (32.2%) ( P<0.0001; OR=3.396; 95%CI=2.036-5.664). The median CL response was significantly higher among the non-ESBL producers (76.9%) than among the ESBL producers (52.6%) ( P=0.034). The two groups did not differ in their ability to resist intracellular killing by PMNLs ( P>0.05), with strains inducing high levels of CL response having significantly lower survival rates (31.8% vs. 42.4%) than strains inducing low levels of CL response (164% vs. 200%) ( P<0.01). The frequencies of the K2 and the K25 serotypes were significantly higher among ESBL-producing strains (17.8% and 22.2%, respectively) than among the non-ESBL producers (6.2% and 1.7%, respectively) ( P=0.0057 and P<0.0001). Of the 77 Klebsiella K serotypes, 71 were detectable among the non-ESBL producers, but only 24 were detectable among the ESBL producers. ESBL-producing Klebsiella pneumoniae strains might have a greater pathogenic potential by virtue of their ability to escape the phagocytic activity of PMNLs.
authors.affiliation: Department of Medical Microbiology and Virology, University Hospital Schleswig-Holstein, Campus Kiel, Brunswiker Strasse 4, 24105 Kiel, Germany. sahly@medmicrobio.uni-kiel.de
authors.forename: H
authors.initials: H
authors.lastname: Sahly
authors.forename: H
authors.initials: H
authors.lastname: Aucken
authors.forename: V J
authors.initials: VJ
authors.lastname: Benedi
authors.forename: C
authors.initials: C
authors.lastname: Forestier
authors.forename: V
authors.initials: V
authors.lastname: Fussing
authors.forename: D S
authors.initials: DS
authors.lastname: Hansen
authors.forename: I
authors.initials: I
authors.lastname: Ofek
authors.forename: R
authors.initials: R
authors.lastname: Podschun
authors.forename: D
authors.initials: D
authors.lastname: Sirot
authors.forename: D
authors.initials: D
authors.lastname: Sandvang
authors.forename: J M
authors.initials: JM
authors.lastname: Tomás
authors.forename: U
authors.initials: U
authors.lastname: Ullmann
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002478:Cells, Cultured; D016001:Confidence Intervals; D024881:Drug Resistance, Bacterial; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology*; D008163:Luminescent Measurements; D008826:Microbial Sensitivity Tests; D009504:Neutrophils / Q000502:physiology*; D016017:Odds Ratio; D011336:Probability; D016897:Respiratory Burst; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases