Characterization of Extensively Drug-Resistant or Pandrug-Resistant Sequence Type 147 and 101 OXA-48-Producing Klebsiella pneumoniae Causing Bloodstream Infections in Patients in an Intensive Care Unit.

Carbapenem-resistant Klebsiella pneumoniae causes important health care-associated infections worldwide. An outbreak of sequence type 11 (ST11) OXA-48-producing K. pneumoniae (OXA-48-Kp) isolates occurred in Tzaneio Hospital in 2012 and was contained until 2014, when OXA-48-Kp reemerged. The present study involved 19 bloodstream infection (BSI) OXA-48-Kp isolates recovered from 19 intensive care unit (ICU) patients hospitalized between August 2014 and July 2016. MICs were determined by broth microdilution. Beta-lactamase genes were detected by PCR. All isolates were typed by pulsed-field gel electrophoresis/multilocus sequence typing (PFGE/MLST), and 10 representative isolates were typed by next-generation sequencing (NGS). Of the 19 study patients, 9 had previous hospitalizations, and 10 carried OXA-48-Kp prior to BSI isolation; median time from ICU admission to BSI was 29 days. Four OXA-48-Kp isolates belonged to PFGE profile A (ST147) and were pandrug resistant (PDR), while 15 isolates exhibited PFGE profile B (ST101) and were extensively drug resistant. Genes detected via NGS resistome analysis accounted for most of the resistance phenotypes, except for tigecycline and fosfomycin. Insertional inactivation of mgrB (distinct per clone) conferred colistin resistance in all 19 isolates. NGS single nucleotide polymorphism (SNP) analysis validated the clonal relatedness of the ST147 and ST101 strains and revealed the possible presence of two index ST147 strains and the microevolution of ST101 strains. Distinct, but highly related, IncL OXA-48-encoding plasmid lineages were identified; plasmids of the ST147 strains were identical with the plasmid of ST11 OXA-48-Kp which caused the 2012 outbreak. In conclusion, biclonal circulation of OXA-48-Kp and, alarmingly, emergence of a PDR clone are reported. These observations, along with the challenging phenotypic detection of OXA-48 producers and the high reported transmissibility of blaOXA-48, necessitate intensive efforts to prevent their further spread.

Containment of an outbreak of KPC-3-producing Klebsiella pneumoniae in Italy.

From March 2009 to May 2009, 24 carbapenem-resistant Klebsiella pneumoniae isolates were recovered from 16 patients hospitalized in an Italian intensive care unit (ICU). All isolates contained KPC-3 carbapenemase and belonged to a single pulsed-field gel electrophoresis (PFGE) clone of multilocus sequence type 258 (designated as ST258). A multimodal infection control program was put into effect, and the spread of the KPC-3-producing K. pneumoniae clone was ultimately controlled without closing the ICU to new admissions. Reinforced infection control measures and strict monitoring of the staff adherence were necessary for the control of the outbreak.

Oseltamivir-resistant influenza A(H1N1) 2009 virus in Greece during the post-pandemic 2010-2011 season.

Information on the drug susceptibility of influenza epidemic strains is important for antiviral resistance monitoring. In Greece, the 2009-2010 pandemic waves were very mild and seroprevalence rates remained low after this influenza season, resulting in exclusive detection of the pandemic strain during the 2010-2011 influenza season. In the present study during the post-pandemic 2010-2011 season, 50 consecutive influenza A(H1N1) 2009 virus-positive samples from patients hospitalised in Greek hospitals were analysed for resistance to the neuraminidase inhibitor oseltamivir. All patients were hospitalised with severe influenza complications and had previously received oseltamivir. Influenza A(H1N1) 2009 virus detection and testing for oseltamivir resistance were performed with real-time PCR amplification assays. The H275Y substitution associated with resistance to oseltamivir was identified in two immunocompetent patients who received oseltamivir treatment for 3 days and 5 days, respectively. In both cases, patients were discharged in good condition despite development of resistance to antiviral treatment.