An Update of the Evolving Epidemic of blaKPC Carrying Klebsiella pneumoniae in Sicily, Italy, 2014: Emergence of Multiple Non-ST258 Clones

Abstract

BackgroundIn Italy, Klebsiella pneumoniae carbapenemase producing K. pneumoniae (KPC-Kp) strains are highly endemic and KPC producing CC258 is reported as the widely predominating clone. In Palermo, Italy, previous reports have confirmed this pattern. However, recent preliminary findings suggest that an epidemiological change is likely ongoing towards a polyclonal KPC-Kp spread. Here we present the results of molecular typing of 94 carbapenem non susceptible K. pneumoniae isolates detected during 2014 in the three different hospitals in Palermo, Italy.Methods and ResultsNinety-four consecutive, non replicate carbapenem non susceptible isolates were identified in the three largest acute general hospitals in Palermo, Italy, in the six-month period March-August 2014. They were characterized by PCR for β-lactam, aminoglycoside and plasmid mediated fluoroquinolone resistance genetic determinants. The mgrB gene of the colistin resistant isolates was amplified and sequenced. Clonality was assessed by pulsed field gel electrophoresis and multilocus sequence typing. Eight non-CC258 sequence types (STs) were identified accounting for 60% of isolates. In particular, ST307 and ST273 accounted for 29% and 18% of isolates. CC258 isolates were more frequently susceptible to gentamicin and non-CC258 isolates to amikacin. Colistin non susceptibility was found in 42% of isolates. Modifications of mgrB were found in 32 isolates.ConclusionsConcurrent clonal expansion of some STs and lateral transmission of genetic resistance determinants are likely producing a thorough change of the KPC-Kp epidemiology in Palermo, Italy. In our setting mgrB inactivation proved to substantially contribute to colistin resistance. Our findings suggest the need to continuously monitor the KPC-Kp epidemiology and to assess by a nationwide survey the possible shifting towards a polyclonal epidemic.

Molecular Epidemiology of Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae in Serbia from 2013 to 2016

“…bla has been commonly associated with ST101 worldwide and, according to the results of an 11-year (2001 to 2011) molecular epidemiologic study of bla in Europe and North Africa, ST101 is the most frequently observed sequence type (13). Among the carbapenem-resistant K. pneumoniae STs identified in this study, the emergence of colistin resistance had been already reported in KPC-2-producing ST101 (14) and bla KPC-2 -and bla CTX-M -producing ST307 (15,16). Carbapenem-and colistin-resistant isolates of ST437 have been reported previously (17).…”

Global Assessment of the Activity of Tigecycline against Multidrug-Resistant Gram-Negative Pathogens between 2004 and 2014 as Part of the Tigecycline Evaluation and Surveillance Trial

“…Further surveillance will be needed to follow this trend. In their study of bla KPC -carrying K. pneumoniae in Palermo, Italy, Bonura et al (16) reported a shift toward a polyclonal epidemic, which highlights that the evolution of resistance is complex and that the importance of changing patterns of resistance should not be underestimated.…”

Double Copies of bla KPC-3 ::Tn 4401a on an IncX3 Plasmid in Klebsiella pneumoniae Successful Clone ST512 from Italy

“…The epidemiology of KPC-producing K. pneumoniae in Palermo, Italy, also confirmed the emergence of ST258 beginning in 2008 (4). More recently, a 6-month surveillance performed in Sicily suggested that a major epidemiological change is likely ongoing in this geographic area, with ST258 still being prevalent but circulating along with several additional STs, including ST307 and ST273 (4).…”