OBJECTIVE: To determine whether 15 multiresistant Pseudomonas aeruginosa isolates from an intensive care unit (ICU) outbreak were related, were endemic, and belonged to the O:12 European clone. METHODS: Forty-six P. aeruginosa isolates from a large hospital were investigated with respect to their antibiotic resistance profiles, serogroups, bacteriocin types and DNA fingerprints obtained by pulsed-field gel electrophoresis (PFGE) of genomic DNA digested with Xbal. RESULTS: Fourteen of the ICU outbreak isolates were indeed identical with respect to their serogroup, O:11, pyocin type, 10/a, and PFGE type, A. Clone A was endemic and dominant throughout the hospital, even though, within the ICU, it underwent phenotypic alterations, such as loss of cell wall lipopolysaccharide side-chains, or acquisition of ceftazidime and imipenem resistance. Bacteriocin typing was more discriminatory than serotyping, but PFGE could differentiate further among phenotypically identical strains. It also allowed the tracking of an O:6 strain, as it was becoming gradually more resistant and undergoing a bacteriocin-type conversion while remaining genotypically unaltered. CONCLUSIONS: Using three typing methods, a nosocomial multiresistant strain distinct from the previously described dominant European O:12 clone was characterized, and the ability of PFGE to identify clonal isolates even when these appear phenotypically distinct was demonstrated.
OBJECTIVE: To determine whether 15 multiresistant Pseudomonas aeruginosa isolates from an intensive care unit (ICU) outbreak were related, were endemic, and belonged to the O:12 European clone. METHODS: Forty-six P. aeruginosa isolates from a large hospital were investigated with respect to their antibiotic resistance profiles, serogroups, bacteriocin types and DNA fingerprints obtained by pulsed-field gel electrophoresis (PFGE) of genomic DNA digested with Xbal. RESULTS: Fourteen of the ICU outbreak isolates were indeed identical with respect to their serogroup, O:11, pyocin type, 10/a, and PFGE type, A. Clone A was endemic and dominant throughout the hospital, even though, within the ICU, it underwent phenotypic alterations, such as loss of cell wall lipopolysaccharide side-chains, or acquisition of ceftazidime and imipenem resistance. Bacteriocin typing was more discriminatory than serotyping, but PFGE could differentiate further among phenotypically identical strains. It also allowed the tracking of an O:6 strain, as it was becoming gradually more resistant and undergoing a bacteriocin-type conversion while remaining genotypically unaltered. CONCLUSIONS: Using three typing methods, a nosocomial multiresistant strain distinct from the previously described dominant European O:12 clone was characterized, and the ability of PFGE to identify clonal isolates even when these appear phenotypically distinct was demonstrated.
Authors: Olga Zaborina; Christopher Holbrook; Yimei Chen; Jason Long; Alexander Zaborin; Irina Morozova; Hoylan Fernandez; Yingmin Wang; Jerrold R Turner; John C Alverdy Journal: PLoS Pathog Date: 2008-02-08 Impact factor: 6.823
Authors: Moayad Alhariri; Majed A Majrashi; Ali H Bahkali; Faisal S Almajed; Ali O Azghani; Mohammad A Khiyami; Essam J Alyamani; Sameera M Aljohani; Majed A Halwani Journal: Int J Nanomedicine Date: 2017-09-18