Complete genome sequence of novel T7-like virus vB_KpnP_KpV289 with lytic activity against Klebsiella pneumoniae.

A novel bacteriophage, vB_KpnP_KpV289, lytic for hypermucoviscous strains of Klebsiella pneumoniae, was attributed to the family Podoviridae, subfamily Autographivirinae, genus T7likevirus based on transmission electron microscopy and genome analysis. The complete genome of the bacteriophage vB_KpnP_KpV289 consists of a linear double-stranded DNA of 41,054 bp including 179-bp direct-repeat sequences at the ends and 51 open reading frames (ORFs). The G+C content is 52.56 %. The phage was shown to lyse 15 out of 140 (10.7 %) K. pneumoniae strains belonged to the capsular types K-1, K-2, and K-57 and strains without a determined capsular type, including a hypermucoviscous strain of the novel sequence type ST-1554.

The spread of bla OXA-48 and bla OXA-244 carbapenemase genes among Klebsiella pneumoniae, Proteus mirabilis and Enterobacter spp. isolated in Moscow, Russia.

BACKGROUND: The spread of carbapenemase-producing Enterobacteriaceae (CPE) is a great problem of healthcare worldwide. Study of the spread for bla OXA-48-like genes coding epidemically significant carbapenemases among hospital pathogens is important for the regional and global epidemiology of antimicrobial resistance. METHODS: Antibacterial resistant isolates of Klebsiella pneumoniae (n = 95) from 54 patients, P. mirabilis (n = 32) from 20 patients, Enterobacter aerogenes (n = 6) from four patients, and Enterobacter cloacae (n = 4) from four patients were collected from January, 2013 to October, 2014 in neurosurgical intensive care unit (ICU) of the Burdenko Neurosurgery Institute, Moscow. Characteristics of the isolates were done using susceptibility tests, PCR detection of the resistance genes, genotyping, conjugation, DNA sequencing, and bioinformatic analysis. RESULTS: Major strains under study were multi drug resistant (MDR), resistant to three or more functional classes of drugs simultaneously-98.9 % K. pneumoniae, 100 % P. mirabilis, one E. aerogenes isolate, and one E. cloacae isolate. Molecular-genetic mechanism of MDR in K. pneumoniae and P. mirabilis isolates were based on carrying of epidemic extended-spectrum beta-lactamase bla CTX-M-15 gene (87.2 and 90.6 % accordingly), carbapenemase bla OXA-48-like gene (55.3 and 23.3 % accordingly), and class 1 (54.8 and 31.3 % accordingly) and class 2 (90.6 % P. mirabilis) integrons. The bla OXA-48-like-positive K. pneumoniae were collected during whole two-year surveillance period, while P. mirabilis and Enterobacter spp. carrying bla OXA-48-like genes were detected only after four and 18 months after the research start, respectively. The bla OXA-48-like gene acquisition was shown for P. mirabilis isolates collected from five patients and for E. cloacae isolate collected from one patient during their stay in the ICU, presumably from bla OXA-48-like-positive K. pneumoniae. The source of the bla OXA-244 gene acquired by E. aerogenes isolates and the time of this event were not recognized. CONCLUSIONS: The expanding of CPE in the surveyed ICU was associated with the spread of bla OXA-48 and bla OXA-244 carbapenemase genes documented not only among K. pneumoniae, well-known bacterial host for such genes, but among P. mirabilis, E. aerogenes, and E. cloacae.