Dissemination of IMP-6-producing Pseudomonas aeruginosa ST244 in multiple cities in China

Abstract

Pseudomonas aeruginosa is an important opportunistic pathogen responsible for nosocomial infections and is currently reported to be a worldwide nosocomial menace. The aim of this study was to investigate the epidemiological traits and the distribution of metallo-β-lactamases (MBLs)-producing P. aeruginosa clinical isolates in ten cities in China between January 2010 and May 2012. Antimicrobial susceptibility was determined by disc diffusion assay and the minimum inhibitory concentrations (MICs) of imipenem and meropenem were also determined by the Etest according to Clinical and Laboratory Standards Institute (CLSI) guidelines. In addition, polymerase chain reaction (PCR) and DNA sequencing were applied to detect bla MBL genes, and their epidemiological relationships were investigated by multilocus sequence typing (MLST). Of 368 P. aeruginosa isolates, MLST analysis identified 138 sequence types (STs), including 122 known and 16 novel STs, and the most frequently detected clone was ST244, followed by ST235. Besides, our study revealed that 25 isolates carried the bla IMP-6 gene and three isolates carried the bla VIM-2 gene, and a probe specific for both genes could be hybridised to an ~1,125-kb fragment in all isolates. Interestingly, all of the bla IMP-6-producing isolates shared an identical ST, ST244, and exhibited a higher level of resistance to several antibiotics. Overall, these observations suggest that P. aeruginosa ST244 carrying the chromosomally located bla IMP-6 gene is widely disseminated in multiple cites in China.

Occurrence of VIM-4 metallo-β-lactamase-producing Pseudomonas aeruginosa in an Algerian hospital

“…MBLs are commonly associated with epidemic high-risk clones [36]. The clone belonging to ST244 was the most frequent in our study and corresponded to the second most prevalent Mediterranean P. aeruginosa clone [37] and further was detected in Asia [38]. Similarly, the ST1076 clone was also reported among clinical isolates of P. aeruginosa in Algeria [11,13] with imipenemsusceptible and VIM-4 producing P.aeruginosa, also Sefraoui et al [10] detected the ST 381 in imipenemsuscpetible strains of P.aeruginosa.…”

Opening Pandora’s box: high level resistance to antibiotics of last resort in Gram negative bacteria from Nigeria

“…Isolates of this sequence type have been seen in the UK[16], and have also been reported previously as carrying VIM-2 or IMP-1 in Norway (in an isolate thought to be imported from Ghana)[36], Japan[37], and South Africa[38]. The other P. aeruginosa sequence type identified in this study (ST244) is a globally disseminated P. aeruginosa clone identified in several countries, including Poland[39], Brazil[40], Spain[41], South Korea[42], the Czech Republic[43], Greece[44], Russia[45], China [46] and Tanzania[47]. ST244 isolates have been found to carry various carbapenemases including IMP and VIM enzymes as well as extended-spectrum ß-lactamases, such as PER-1 and VEB-1[39, 48].…”

Characteristics of Metallo-β-Lactamase-Producing Pseudomonas aeruginosa in Korea

“…However, there are other MPPA strains that have also been identified in Asian countries: ST357 in Japan, ST773 in India, and ST298 in Taiwan. Recently, dissemination of IMP-6 MPPA ST244 in China was reported [ 23 ]. There is no evidence though, whether MPPA ST309 and ST463 entered Korea from foreign countries, or the strains acquired the MBL gene by horizontal transfer in this country itself.…”