Emergence of New Sequence Type OXA-48 Carbapenemase-Producing Enterobacteriaceae in Kuwait.

The aim of this study was to investigate the infections due to OXA-48 carbapenemase-producing bacteria in tertiary hospitals in Kuwait (September 2011 to April 2013) and to determine the sequence types (STs) of the corresponding isolates. Eleven OXA-48 carbapenemase-producing Enterobacteriaceae isolates were recovered from patients treated in nine different hospitals in Kuwait. Susceptibility testing to eighteen antibiotics was done using the E-test.

The mgrB gene as a key target for acquired resistance to colistin in Klebsiella pneumoniae.

Objectives: Alterations in the PhoPQ two-component regulatory system may be associated with colistin resistance in Klebsiella pneumoniae. MgrB is a small transmembrane protein produced upon activation of the PhoPQ signalling system, and acts as a negative regulator on this system. We investigated the role of the MgrB protein as a source of colistin resistance in a series of K.

Multidrug-resistant Acinetobacter baumannii strains carrying the bla(OxA-23) and the bla(GES-11) genes in a neonatology center in Tunisia.

Multidrug-resistant and difficult-to-treat Acinetobacter baumannii may be responsible for nosocomial infections. The production of carbapenem-hydrolyzing class D β-lactamases (CHDLs) and extended-spectrum β-lactamase (ESBLs) of the GES type possessing a carbapenemase activity has been increasingly reported worldwide in A. baumannii.

The difficult-to-control spread of carbapenemase producers among Enterobacteriaceae worldwide.

The spread of carbapenemase producers in Enterobacteriaceae has now been identified worldwide. Three main carbapenemases have been reported; they belong to three classes of β-lactamases, which are KPC, NDM, and OXA-48. The main reservoirs of KPC are Klebsiella pneumoniae in the USA, Israel, Greece, and Italy, those of NDM are K.

Resistance to colistin associated with a single amino acid change in protein PmrB among Klebsiella pneumoniae isolates of worldwide origin.

A series of colistin-resistant Klebsiella pneumoniae isolates recovered from different countries was investigated in order to evaluate the involvement of the PmrA/PmrB two-component system in this resistance. Six isolates possessed a mutated PmrB protein, which is encoded by the pmrB gene, part of the pmrCAB operon involved in lipopolysaccharide modification. The same amino acid substitution (Thr157Pro) in PmrB was identified in the six isolates.

IncH-type plasmid harboring bla CTX-M-15, bla DHA-1, and qnrB4 genes recovered from animal isolates.

The whole sequence of plasmid pENVA carrying the extended-spectrum β-lactamase gene blaCTX-M-15 was determined. It was identified from a series of clonally related Klebsiella pneumoniae sequence type 274 strains recovered from companion animals. This plasmid was 253,984 bp in size and harbored, in addition to blaCTX-M-15, a large array of genes encoding resistance to many antibiotic molecules, including β-lactams (blaTEM-1, blaDHA-1), aminoglycosides (aacA2, aadA1), tetracycline (tetA), quinolones (qnrB4), trimethoprim (dfrA15), and sulfonamides (two copies of sul1).

Bloodstream infections caused by Pseudomonas spp.: how to detect carbapenemase producers directly from blood cultures.

The Carba NP test has been evaluated to detect carbapenemase-producing Pseudomonas spp. directly from blood cultures. This rapid and cost-effective test permits an early identification of carbapenemase-producing Pseudomonas spp.

Strategy for rapid detection of carbapenemase-producing Enterobacteriaceae.

A prospective survey was conducted on 862 Enterobacteriaceae isolates with reduced susceptibility to carbapenems. The Carba NP test, UV spectrophotometry, and a DNA microarray were used to detect carbapenemase producers, and the results were compared to those from PCR and sequencing. The 172 carbapenemase producers were detected using the Carba NP test and UV spectrophotometry, whereas the DNA microarray failed to detect IMI producers.

Eighteen years of experience with Acinetobacter baumannii in a tertiary care hospital.

Objective: To characterize the descriptive and molecular epidemiology of Acinetobacter baumannii in our hospital.

Design: Longitudinal analysis of electronic microbiology laboratory records and isolates.

Setting: A 1,500 bed public teaching hospital in the Miami area.

Genetic basis of antibiotic resistance in pathogenic Acinetobacter species.

Antibiotic resistance in Acinetobacter spp., particularly Acinetobacter baumannii, is increasing rapidly. A.

Genetic support of extended-spectrum beta-lactamases.

Genes encoding extended-spectrum beta-lactamases (ESBLs) have been reported in a variety of Gram-negative species, mostly in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. They are mostly either TEM or SHV derivatives, CTX-M-like enzymes--now emerging worldwide--or, less frequently, VEB, GES, and PER ESBLs. The mechanisms responsible for their acquisition are very diverse, and mostly are related to insertion sequences (ISs), transposons, class 1 integrons, and also sul1-type integrons containing the ISCR1 element.

Carbapenem resistance in Acinetobacter baumannii: mechanisms and epidemiology.

The increasing trend of carbapenem resistance in Acinetobacter baumannii worldwide is a concern since it limits drastically the range of therapeutic alternatives. Metallo-beta-lactamases (VIM, IMP, SIM) have been reported worldwide, especially in Asia and western Europe, and confer resistance to all beta-lactams except aztreonam. The most widespread beta-lactamases with carbapenemase activity in A.