KPC-2-producing Enterobacter cloacae and pseudomonas putida coinfection in a liver transplant recipient.
ABSTRACT Carbapenemases are among the newest resistance mechanisms to emerge in some gram-negative bacteria. We describe bacteremia in a critically ill liver transplant recipient infected with KPC-2-producing Enterobacter cloacae and Pseudomonas putida. Although this enzyme has been previously described in Enterobacter spp., this is the first report of KPC carbapenemase in P. putida.
Full-textDOI: · Available from: Jason W Bennett, Jun 03, 2015
SourceAvailable from: Leila Azimi[Show abstract] [Hide abstract]
ABSTRACT: Wound infection associated with carbapenem-resistant Pseudomonas aeruginosa in burn patients is a growing problem. One of the main mechanisms of resistance to carbapenem antibiotics is the ability of P. aeruginosa to produce carbapenemase enzymes. Klebsiella pneumonia carbapemenase (KPC) is an important type of carbapenemase which can hydrolyze carbapenem antibiotics. The Modified Hodge Test (MHT) and boronic acid as a KPC inhibitor are two phenotypic methods used for detection of carbapenemase. The sensitivity and specificity of these two phenotypic tests for the identification of KPC can be measured by PCR. In this study, 241 P. aeruginosa strains were isolated from wounds of hospitalized burn patients. Carbapenem-resistant P. aeruginosa isolates were determined by the disk diffusion method. KPC-producing carbapenem-resistant strains were examined using the Modified Hodge Test, followed by boronic acid. Further, strains with positive responses to MHT and boronic acid tests were analyzed with the PCR molecular method. One hundred eighty-six of 241 isolates were resistant to carbapenems and 75 were positive in the MHT. Three exhibited an at least 5-mm diameter difference when meropenem was combined with boronic acid vs meropenem alone in the boronic acid test. Two strains had a specific band with primer No.1 after gel electrophoresis. This study showed that MHT, despite excellent sensitivity, has variable specificity independent of bacterial species. Further, the use of KPC inhibitors such as boronic acid did not yield favorable sensitivity and specificity among the specimens from Iranian patients. Thus, it seems that sequencing after PCR should be considered the gold standard for the detection of KPC-producing P. aeruginosa.03/2014; 9(1):Doc06. DOI:10.3205/dgkh000226
[Show abstract] [Hide abstract]
ABSTRACT: Here we describe a case of in vivo horizontal interspecies transmission of a KPC-2-producing plasmid from a Klebsiella pneumoniae to an Enterobacter aerogenes strain in the same patient. The patient’s gut flora initially contained a carbapenem-susceptible E. aerogenes strain and 10 days after admission a KPC-2-positive K. pneumoniae. Three months after admission, a KPC-2-positive E. aerogenes was identified in fecal surveillance cultures. This isolate was isogenic with the initial E. aerogenes and contained a KPC-2-coding plasmid identical to that of the K. pneumoniae. The patient developed bacteraemia by the KPC-2-positive K. pneumoniae 17 days after her first colonization. In vivo horizontal transmission of blaKPC-carrying plasmids between bacterial species underscores the importance of antibiotic stewardship along with implementation of infection control measures for the containment of KPC-producers.
[Show abstract] [Hide abstract]
ABSTRACT: Due to the lack of detailed reports of Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacteria in Ontario, Canada, we perform a molecular characterization of KPC-producing Enterobacteriaceae submitted to the provincial reference laboratory from 2008 to 2011. Susceptibility profiles were accessed by E-test. Molecular types of isolates were determined by pulse-field gel electrophoresis (PFGE) and multilocus sequence typing. Screening of ß-lactamase genes was performed by multiplex PCR and alleles were identified by DNA sequencing. The genetic platform of blaKPC gene was analyzed by PCR. Plasmid replicons were typed using PCR-based typing approach. KPC-plasmids were also evaluated by S1 nuclease-PFGE and Southern blot. Thirty unique clinical isolates (26 Klebsiella pneumoniae, 2 Enterobacter cloacae, 1 Citrobacter freundii and 1 Raoultella ornithinolytica) were identified as blaKPC positive: 4 in 2008, 3 in 2009, 10 in 2010 and 13 in 2011. The majority exhibited resistance to carbapenems, cephalosporins and fluoroquinolones and two isolates were also resistant to colistin. The isolates harbored blaKPC-2 (n = 23) or blaKPC-3 (n = 7). blaTEM-1 (n = 27) was commonly detected and occasionally blaOXA-1 (n = 3) and blaCTX-M-15 (n = 1). As expected, all K. pneumoniae isolates carried blaSHV-11. blaKPC genes were identified on Tn4401a (n = 20) or b (n = 10) isoforms, on plasmids of different sizes belonging to the incompatibility groups IncFIIA (n = 19), IncN (n = 3), IncI2 (n = 3), IncFrep (n = 2) and IncA/C (n = 1). The occurrence of KPC ß-lactamase in Ontario was mainly associated with the spread of the K. pneumoniae clone ST258.PLoS ONE 12/2014; 9(12):e116421. DOI:10.1371/journal.pone.0116421 · 3.53 Impact Factor