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Objectives: Genomic surveillance of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is crucial for virulence, drug-resistance monitoring, and outbreak containment., Methods: Genomic analysis on 87 KPC-Kp strains isolated from 3 Northern Italy hospitals in 2019-2021 was performed by whole genome sequencing (WGS), to characterize resistome, virulome, and mobilome, and to assess potential associations with phenotype resistance and clinical presentation. Maximum Likelihood and Minimum Spanning Trees were used to determine strain correlations and identify potential transmission clusters., Results: Overall, 15 different STs were found; the predominant ones included ST307 (35, 40.2%), ST512/1519 (15, 17.2%), ST20 (12, 13.8%), and ST101 (7, 8.1%). 33 (37.9%) KPC-Kp strains were noticed to be in five transmission clusters (median number of isolates in each cluster: 5 [3-10]), four of them characterized by intra-hospital transmission. All 87 strains harbored Tn4401a transposon, carrying bla KPC-3 (48, 55.2%), bla KPC-2 (38, 43.7%), and in one case (1.2%) bla KPC-33, the latter gene conferred resistance to ceftazidime/avibactam (CZA). Thirty strains (34.5%) harbored porin mutations; of them, 7 (8.1%) carried multiple Tn4401a copies. These strains were characterized by significantly higher CZA minimum inhibitory concentration compared with strains with no porin mutations or single Tn4401a copy, respectively, even if they did not overcome the resistance breakpoint of 8 ug/mL. Median 2 (IQR:1-2) virulence factors per strain were detected. The lowest number was observed in ST20 compared to the other STs (p<0.001). While ST307 was associated with infection events, a trend associated with colonization events could be observed for ST20., Conclusions: Integration of genomic, resistance score, and clinical data allowed us to define a relative diversification of KPC-Kp in Northern Italy between 2019 and 2021, characterized by few large transmission chains and rare inter-hospital transmission. Our results also provided initial evidence of correlation between KPC-Kp genomic signatures and higher MIC levels to some antimicrobial agents or colonization/infection status, once again underlining WGS's importance in bacterial surveillance., (© 2024. The Author(s).)

Klebsiella pneumoniae (KP) is an important pathogen involved in serious nosocomial infections all over the world. Here, we describe the first report on a blood-stream infection caused by an OXA-48/NDM-1 ST101-KP, in Italy. The patient was an Italian woman, transferred from Cairo Hospital to a Neurosurgery ward in Cuneo (IT). The detection described here enhances the need for an effective National infection control strategy in Italy.

In the past years, the Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae sequence type 258 (ST258) became an important worldwide spread nosocomial pathogen. Recent evidence shows that the global epidemiology is changing, with the rise of new lineages. In this study we report the microbiological and genomic features of two VIM-1-producing K. pneumoniae isolates belonging to the emerging ST307. Two extensively drug-resistant K. pneumoniae strains, collected between May and June 2017, were confirmed as bla VIM positive by GeneXpert system. The whole-genome sequencing revealed that both KpV&#95;S&#95;1 and KpV&#95;S&#95;2 isolates harbored bla VIM-1 and bla CTX-M-15 genes, besides qnrS1 and qnrB1 , strB, mphA, tetR clones in a hospital setting should alert on the changing of the epidemiological situation in Italy, usually endemic reservoir of KPC enzyme.tetA determinants. KpV&#95;S&#95;1 and KpV&#95;S&#95;2 isolates belonged to ST661 and ST307, respectively. Both STs have been recently reported as responsible of outbreaks in several European countries. The detection of bla VIM-1 gene in nonpredominant K. pneumoniae clones in a hospital setting should alert on the changing of the epidemiological situation in Italy, usually endemic reservoir of KPC enzyme.

Klebsiella pneumoniae is a common nosocomial pathogen involved in many infectious diseases such as bacteraemia, urinary and respiratory tract infections. It is responsible for the rise in morbidity and mortality rates since most clinical isolates exhibit resistance to several antibiotics. Moreover, the epidemiology of these nosocomial infections is variable across countries and regions. From January 2015 to December 2017 we retrospectively analysed the bloodstream infections caused by K. pneumoniae strains in hospitalised patients with the aim of studying the temporal trends of wild type (WT), multi-drug resistant (MDR), extended drug resistant (XDR), pan-drug resistant (PDR) and carbapenem-resistant (CR) strains. In all, 439 K. pneumoniae isolates from 356 patients were collected from all units of the Policlinico of Bari. The majority of clinical isolates were collected from the intensive care unit (125, 28.47%), haematology (34, 7.74%), rehabilitation (27, 6.15%) and cardiac surgery wards (25, 5.69%). Moreover, the majority of the isolates were classified as CR (325, 74.03%, 95%CI: 69.61-78.19) and XDR (255, 58.09%, 95%CI: 53.31-62.72). Annual prevalence rates and monthly counts were analysed using the Chi Squared test for trends and the Poisson regression with multiple p-value correction according to Benjamini and Hochberg's procedure. The annual relative frequencies of the XDR and CR K. pneumoniae isolates decreased significantly from 63.37% to 48.44% and from 78.48% to 63.28% respectively, while WT K. pneumoniae significantly increased from 13.95% to 23.44%. Poisson regression analysis confirmed the presence of a decreasing monthly trend for the XDR and CR K. pneumoniae count series. In order to control the spread of antibiotic resistance, more inclusive surveillance data will be needed to either confirm these results or improve antibiotic stewardship measures.

Aim: To describe the phenotypic and genotypic profiles of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) strains isolated from patients with invasive infections at an Italian university hospital in order to assess the epidemiological trend., Methods: An observational prospective study was undertaken at the University Hospital of Sassari, Italy to detect KPC-Kp strains in patients with invasive bacteraemia. Isolates were identified phenotypically; carbapenemase production was assessed using phenotypic and genotypic methods. Sequencing of blaKPC genes, pulsed-field gel electrophoresis and multi-locus sequence typing were performed., Results: During the period 2015-2017, 46 cases of invasive infection with K. pneumoniae were recorded. Two-thirds (67.4%) of the patients were male, and the mean age was 69.4 years. Most patients had at least one comorbidity (56.5%) and/or had been hospitalized previously (70.5%), 81.8% had current or recent medical device use, and 85.4% had recent antibiotic exposure. The mortality rate was 52.3%. A multi-drug-resistant pattern (including carbapenems, fluoroquinolones, third-/fourth-generation cephalosporins) was shown for all K. pneumoniae isolates. KPC-3 and -2 were produced by all strains. The most common sequence types were 512 (91.3%) and 101 (8.7%), grouped into three clusters (A, A1 and B)., Conclusions: A high incidence of KPC-Kp in patients with invasive infections was recorded at an Italian university hospital compared with the incidence measured before 2015. This study confirmed the importance of the KPC-3 carbapenemase variant, as reported by other Italian studies. High mortality and comorbidity rates appear to be associated with KPC-Kp infection., (Copyright © 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Objectives: We described Klebsiella pneumoniae producing carbapenemase (CPKP) spread from 01/01/2015 to 13/09/16 in a tertiary level hospital., Methods: The first positive surveillance rectal swab (SRS) or clinical sample (CS) collected in the medical department (MD), surgical department (SD) and intensive care department (ICD) were included in the study. A validated in-house Real-Time PCR method was used to detect carbapenemases; multilocus sequence typing (MLST) was used for further characterization of the strains., Results: 21535 patients were included: 213 CPKP strains from surveillance rectal swab (SRS) and 98 from clinical samples (CS) were collected. The percentage of CPKP detected in SRS with respect to CS increased in the medical MD from 2015 to 2016 (p=0.01) and in ICD from 2012 to 2015 (p=0.0001), while it decreased in SD from 2014 to 2016 (p=0.003); 68.5% of the positive SRS had a previous negative SRS; CPKP was more frequently identified in CS than in SRS in MD. Twelve strains harboured more than one carbapenemase gene. Many other species harbouring a carbapenemase gene were collected., Conclusions: MDs need more inclusive surveillance criteria. The late detection of positive SRS underlined the risk of colonization during hospitalization., (Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Carbapenem-resistant Klebsiella pneumoniae infections are reported with increasing frequency elsewhere in the world, representing a worrying phenomenon for global health. In Italy, there are hotspot data on the diffusion and type of carbapenemase-producing Enterobacteriaceae and K. pneumoniae in particular, with very few data coming from Apulia and Basilicata, two regions of Southern Italy. This study was aimed at characterizing by phenotypic and genotypic methods carbapenem-resistant K. pneumoniae isolated from several Hospitals of Apulia and Basilicata, Southern Italy. Antibiotic susceptibility was also evaluated. The relatedness of carbapenemase-producing K. pneumoniae strains was established by pulsed-field gel electrophoresis (PFGE). Among the 150 K. pneumoniae carbapenemase producers, KPC-3 genotype was the most predominant (95%), followed by VIM-1 (5%). No other genotypes were found and no co-presence of two carbapenemase genes was found. A full concordance between results obtained by both the phenotypic and the genotypic tests was observed. All strains were resistant to β-lactam antibiotics including carbapenems, and among antibiotics tested, only tetracycline and gentamycin showed low percentage of resistance (18% and 15%, respectively). Resistance to colistin was detected in 17.3% of strains studied. The analysis of PFGE profiles of the carbapenemases-positive strains shows that one group (B) of the five (A to E) main groups identified was the most prevalent and detected in almost all the hospitals considered, while the other groups were randomly distributed. Three different sequence types (ST 307, ST 258, and ST 512) were detected with the majority of isolates belonging to the ST 512. Our results demonstrated the wide diffusion of K. pneumoniae KPC-3 in the area considered, the good concordance between phenotypic and genotypic tests. Gentamicin and colistin had a good activity against these strains., (© 2017 APMIS. Published by John Wiley & Sons Ltd.)

K. pneumoniae isolates carrying blaKPC-3 gene were collected to perform Bayesian phylogenetic and selective pressure analysis and to apply homology modeling to the KPC-3 protein. A dataset of 44 bla kpc -3 gene sequences from clinical isolates of K. pneumoniae was used for Bayesian phylogenetic, selective pressure analysis and homology modeling. The mean evolutionary rate for bla kpc -3 gene was 2.67×10 -3 substitution/site/year (95% HPD: 3.4×10 -4- 5.59×10 - 3 ). The root of the Bayesian tree dated back to the year 2011 (95% HPD: 2007-2012). Two main clades (I and II) were identified. The population dynamics analysis showed an exponential growth from 2011 to 2013 and the reaching of a plateau. The phylogeographic reconstruction showed that the root of the tree had a probable common ancestor in the general surgery ward. Selective pressure analysis revealed twelve positively selected sites. Structural analysis of KPC-3 protein predicted that the amino acid mutations are destabilizing for the protein and could alter the substrate specificity. Phylogenetic analysis and homology modeling of blaKPC-3 gene could represent a useful tool to follow KPC spread in nosocomial setting and to evidence amino acid substitutions altering the substrate specificity., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objectives: The spread of carbapenem-resistant Enterobacteriaceae (CRE) represents one of the most worrisome problems for clinical medicine worldwide. In Italy, the Antibiotic-Resistance-Istituto Superiore di Sanità surveillance network, in collaboration with the Committee for Antimicrobial Agents of the Italian Society of Clinical Microbiologists, promoted a study to investigate the carbapenem-resistance mechanisms, clonal relatedness and capsular typing of a recent collection of carbapenem-resistant Klebsiella pneumoniae (CR-KP)., Methods: A total of 17 laboratories distributed across Italy collected all consecutive non-replicate CR-KP isolated from invasive infections during two different study periods (2011-12 and 2013). Carbapenemase genes were searched for by filter hybridization and confirmed by PCR and sequencing. KPC-producing K. pneumoniae (KPC-KP) were typed by PFGE and MLST. Capsular types were identified by wzi gene typing., Results: Of the collected K. pneumoniae isolates (n = 461), the overall proportion of CR-KP was 36.2% (n = 167). The majority (97%) of the CR-KP were positive for the bla KPC gene. Among the KPC-KP population, nine different STs were detected with the majority of isolates (94%) belonging to the clonal group (CG) 258. A subpopulation that belonged to ST512 and showed an identical PFGE profile represented the majority (57%) of KPC-KP strains, with a countrywide distribution. Capsular characterization showed the predominance of the wzi154, cps-2 capsular type (88.8% of all CG258 strains). ST258 strains were associated with both cps-1 and cps-2 capsular types, while ST512 was associated with cps-2 only., Conclusions: Although a trend to a polyclonal evolution of the Italian KPC-KP was noted, this study showed that the KPC-KP population remained largely oligoclonal with the wide diffusion of an ST512 lineage carrying cps-2 capsular type and producing the KPC-3 enzyme., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

In this study we report the analysis of 131 Klebsiella pneumoniae (K. pneumoniae) clinical isolates from patients hospitalized in various wards, of Perugia General Hospital, from August 2014 to January 2015. Forty two isolates (32.1 %), were resistant to at least one carbapenem antibiotic and, among these isolates, 14 (33.3 %) exhibited resistance to colistin. All isolates were carbapenemases producers and 41 (97.6 %) harboured the bla KPC gene. Carbapenem-resistant K. pneumoniae isolates (CRKPs) were, also, typed for the genotypic diversity and the results revealed the circulation of two major clusters.This surveillance study evidences the spread of CRKP isolates in Perugia General Hospital and confirms that carbapenem-resistant K. pneumoniae isolates have reached epidemic dissemination in Italy. In addition the percentage of resistance to colistin resulted to be less than that observed in other hospital laboratories across Italy. In conclusion the circulation of these isolates should be monitored and appropriate policy of surveillance must be used, in a target manner, in order to reduce the spread of carbapenem-resistant isolates.

Carbapenem-resistant Klebsiella pneumoniae isolates are an important cause of nosocomial infections. This study evaluated a rapid cost-saving method based on MALDI-TOF technology, was and compared it with phenotypic, genotypic and epidemiological data for characterization of KPC-Kp strains consecutively isolated during a supposed outbreak. Twenty-five consecutive KPC Klebsiella pneumoniae isolates were identified and clustered by the MALDI Biotyper (Bruker, Daltonics). To display and rank the variance within a data set, principal component analysis (PCA) was performed. ClinProTools models were generated to investigate the highest sum of recognition capability and cross-validation. A Class dendrogram of isolates was constructed using ClinproTool. MLST was performed sequencing gapA, infB, mdh, pgi, rpoB, phoE and tonB genes. blakpc and cps genes were typed. Phylogenetic analysis and genetic distance of the KPC gene were performed using the MEGA6 software. PCA analysis defined two clusters, I and II, which were identified in a dendrogram by both temporal split and different antimicrobial susceptibility profiles. These clusters were composed mostly of strains of the same sequence type (ST512), the most prevalent ST in Italy, and the same cps (type 2). In cluster II, blakpc genotype resulted more variable than in cluster I. Phylogenetic analysis confirmed the genetic diversity in both clusters supported by the epidemiological data. Our study confirms that MALDI-TOF can be a rapid and cost-saving method for epidemiological clustering of KPC K. pneumoniae isolates and its association with blakpc genotyping represents a reliable method to recognize possible clonal strains in nosocomial settings.

Multidrug-resistant (MDR) Klebsiella pneumoniae is one of the most important causes of nosocomial infections worldwide. After the spread of strains resistant to beta-lactams at the end of the previous century, the diffusion of isolates resistant to carbapenems and colistin is now reducing treatment options and the containment of infections. Carbapenem-resistant K. pneumoniae strains have spread rapidly among Italian hospitals, with four subclades of pandemic clonal group 258 (CG258). Here we show that a single Italian hospital has been invaded by three of these subclades within 27 months, thus replicating on a small scale the "Italian scenario." We identified a single clone responsible for an epidemic outbreak involving seven patients, and we reconstructed its star-like pattern of diffusion within the intensive care unit. This epidemiological picture was obtained through phylogenomic analysis of 16 carbapenem-resistant K. pneumoniae isolates collected in the hospital during a 27-month period, which were added to a database of 319 genomes representing the available global diversity of K. pneumoniae strains. Phenotypic and molecular assays did not reveal virulence or resistance determinants specific for the outbreak isolates. Other factors, rather than selective advantages, might have caused the outbreak. Finally, analyses allowed us to identify a major subclade of CG258 composed of strains bearing the yersiniabactin virulence factor. Our work demonstrates how the use of combined phenotypic, molecular, and whole-genome sequencing techniques can help to identify quickly and to characterize accurately the spread of MDR pathogens., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Background: In 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 Results: Ninety-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., Conclusions: Concurrent 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.

Klebsiella pneumoniae is at the forefront of antimicrobial resistance for Gram-negative pathogenic bacteria, as strains resistant to third-generation cephalosporins and carbapenems are widely reported. The worldwide diffusion of these strains is of great concern due to the high morbidity and mortality often associated with K. pneumoniae infections in nosocomial environments. We sequenced the genomes of 89 K. pneumoniae strains isolated in six Italian hospitals. Strains were selected based on antibiotypes, regardless of multilocus sequence type, to obtain a picture of the epidemiology of K. pneumoniae in Italy. Thirty-one strains were carbapenem-resistant K. pneumoniae carbapenemase producers, 29 were resistant to third-generation cephalosporins, and 29 were susceptible to the aforementioned antibiotics. The genomes were compared to all of the sequences available in the databases, obtaining a data set of 319 genomes spanning the known diversity of K. pneumoniae worldwide. Bioinformatic analyses of this global data set allowed us to construct a whole-species phylogeny, to detect patterns of antibiotic resistance distribution, and to date the differentiation between specific clades of interest. Finally, we detected an ∼ 1.3-Mb recombination that characterizes all of the isolates of clonal complex 258, the most widespread carbapenem-resistant group of K. pneumoniae. The evolution of this complex was modeled, dating the newly detected and the previously reported recombination events. The present study contributes to the understanding of K. pneumoniae evolution, providing novel insights into its global genomic characteristics and drawing a dated epidemiological scenario for this pathogen in Italy., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

The aim of this study was to characterise carbapenem-resistant Klebsiella pneumoniae isolates that caused an outbreak in a hospital in the south of Spain, originating from a patient transferred in 2012 from Italy. Forty-four K. pneumoniae isolates, recovered from 28 patients, were screened by PCR for extended-spectrum β-lactamase (ESBL) and carbapenemase genes and the products were further sequenced. Plasmids were transferred by electroporation and were classified using PCR-based Inc/rep typing and IncF subtyping. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to determine the genetic relatedness of the isolates. All isolates yielded positive modified Hodge test results, harboured bla(SHV-11), bla(TEM-1) and bla(KPC-3) genes, showed an identical PFGE pattern, and were assigned to clone sequence type 512 (ST512). The bla(KPC-3) gene was located on a 140-kb K2:A-:B-plasmid. In conclusion, the successful K. pneumoniae ST512 clone caused a major outbreak in Spain from an imported case and is the first description of an outbreak in this country due to the KPC-3-producing K. pneumoniae ST512 clone., (Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.)

Starting in 2010, there was a sharp increase in infections caused by Klebsiella pneumoniae resistant to carbapenems in the Emilia-Romagna region in Italy. A region-wide intervention to control the spread of carbapenemase-producing K. pneumoniae (CPKP) in Emilia-Romagna was carried out, based on a regional guideline issued in July 2011. The infection control measures recommended to the Health Trusts (HTs) were: phenotypic confirmation of carbapenemase production, active surveillance of asymptomatic carriers and contact isolation precautions for carriers. A specific surveillance system was activated and the implementation of control measures in HTs was followed up. A significant linear increase of incident CPKP cases over time (p<0.001) was observed at regional level in Emilia-Romagna in the pre-intervention period, while the number of cases remained stable after the launch of the intervention (p=0.48). Considering the patients hospitalised in five HTs that provided detailed data on incident cases, a downward trend was observed in incidence after the release of the regional guidelines (from 32 to 15 cases per 100,000 hospital patient days). The spread of CPKP in Emilia-Romagna was contained by a centrally-coordinated intervention. A further reduction in CPKP rates might be achieved by increased compliance with guidelines and specific activities of antibiotic stewardship.

In intensive care units (ICUs), the most important causes of nosocomial bacterial infections are mainly multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii and Klebsiella pneumoniae strains. Mortality related to these infections is very high due to lack of effective therapy and the severity of patient conditions. This study aimed to assess the prevalence of carbapenem resistance genes in 77 carbapenem-resistant Gram-negative bacteria isolated from severe infections (bloodstream, pulmonary and urinary tract) during the period 1 January to 31 July 2013 in a general ICU in Catania, Italy, and to examine their susceptibility to tigecycline and colistin using two different methods. In total, 52 A. baumannii belonging to the same sequence type (ST) 2 clone and carrying the bla(OXA-23) gene as well as 25 K. pneumoniae carrying bla(KPC-3) were isolated. Four distinct pulsotypes were identified in K. pneumoniae, which correlated with four distinct STs: ST258 and ST512, spread worldwide, and ST147 and ST395 detected for the first time in Italy. A. baumannii isolates showed an XDR profile and were fully susceptible only to colistin; all KPC-producing K. pneumoniae isolates were MDR, whilst colistin was active against 19 of 25 strains. These results show that broth microdilution (BMD) is a reliable in vitro susceptibility test for colistin, above all K. pneumoniae, whilst both the gradient test and BMD are suitable for tigecycline susceptibility testing of A. baumannii., (Published by Elsevier B.V.)

Carbapenem-resistant K. pneumoniae has recently been reported as a new multidrug-resistant nosocomial pathogen. This study reports the emergence of carbapenem-resistant K. pneumoniae strains in Brescia Civic Hospital, Italy. Different samples, collected from April 2012 to February 2013, showed that 29 patients presented infections from multidrug-resistant K. pneumoniae and three of these patients were intestinal carriers. In total, 40 carbapenem-resistant K. pneumoniae strains were isolated from multiple specimens of these patients. In 39 out of 40 samples, we identified the bla(KPC-3) carbapenemase gene variant responsible for bacterial carbapenem resistance. The DiversiLab analysis showed four different genetic patterns within multidrug-resistant K. pneumoniae isolates, with pattern 1 and 2 including 95% of the bacterial strains. Carbapenem-resistant K. pneumoniae strains belonging to patterns 1 and 2 were also detected in the intestinal tract of the three asymptomatic carriers. Moreover, isolation of the same strains in other body sites of the same patients and in bronchial fluid of a non-colonized patient in the same ward indicates an initial dissemination of this pathogen. Our results highlight the emergence of carbapenemase-producing K. pneumoniae strains in different hospital wards and the urgent need for infection control, antibiotic stewardship programmes and utilization of a surveillance and prevention system.

A large outbreak caused by expanded-spectrum cephalosporin-resistant Klebsiella pneumoniae (ESCRKP) was observed in a neonatal intensive care unit (NICU) in central Italy. The outbreak involved 127 neonates (99 colonizations and 28 infections, with seven cases of sepsis and two deaths) over a period of more than 2 years (February 2008 to April 2010). Characterization of the 92 nonredundant isolates that were available for further investigation revealed that all of them except one produced the FOX-7 AmpC-type β-lactamase and belonged to either sequence type 14 (ST14) or ST26. All of the FOX-7-positive isolates were resistant to cefotaxime, ceftazidime, and piperacillin-tazobactam, while 76% were susceptible to cefepime, 98% to ertapenem, 99% to meropenem, and 100% to imipenem. The two carbapenem-nonsusceptible isolates had alterations in the genes encoding outer membrane proteins K35 and K36, which resulted in truncated and likely nonfunctional proteins. The outbreak was eventually controlled by the reinforcement of infection control measures based on a multitiered interventional approach. This is the first report of a large NICU outbreak caused by ESCRKP producing an AmpC-type enzyme. This study demonstrates that AmpC-type enzyme-producing strains can cause large outbreaks with significant morbidity and mortality effects (the mortality rate at 14 days was 28.5% for episodes of sepsis), and it underscores the role of laboratory-based surveillance and infection control measures to contain similar episodes.

Carbapenemase-producing Enterobacteriaceae and Pseudomonas spp. are increasingly reported in many countries all over the world. Due to the resistance of those bacteria to almost all antibiotics (e.g.beta-lactams, aminoglycosides, fluoroquinolones),treatment options are seriously limited. In the Czech Republic, the incidence of carbapenemase-producing Enterobacteriaceae seems to be low, restricted to only three cases detected between 2009 and 2010.Here, we describe molecular typing of 15 carbapenemase-producing Klebsiella pneumoniae isolates identified in the Czech Republic during 2011. Five VIM-1-producing isolates belonging to sequence type (ST)11 and one VIM-4-producing isolate of ST1029 have been detected. blaVIM-1 and blaVIM-4 as a part of class 1 integrons were chromosomally located or carried by a plasmid belonging to A/C replicon type (blaVIM-4). KPC-3-producing isolates of ST512, recovered from six patients, caused an outbreak. Three more isolates producing KPC-2 enzyme belonged to ST258. Both blaKPCgenes were part of the Tn4401a transposon carried on plasmids of the pKpQIL type. The isolates were resistant to all antibiotics tested except colistin and/or gentamicin.Four of these 15 strains were recovered from patients repatriated to the Czech Republic from Greece and Italy. This is the first report of outbreaks caused by carbapenemase-producing Enterobacteriaceae in the Czech Republic.

This article reports an outbreak of colonization by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) sequence type (ST) 258 in a neonatal intensive care unit (NICU) in Palermo, Italy. KPC-Kp ST258 was detected by an active surveillance culture programme. Between 18th September and 14th November 2012, KPC-Kp was isolated from 10 out of 54 neonates admitted in the outbreak period. No cases of infection were recorded. Male sex was associated with colonization, whereas administration of ampicillin- sulbactam plus gentamicin was protective. Infection control interventions interrupted the spread of KPC-Kp without the need to close the NICU to new admissions., (Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

The international project MOSAR was conducted in five rehabilitation centers; patients were screened for rectal carriage of extended-spectrum β-lactamase (ESBL)-producing members of the Enterobacteriaceae. Among 229 Klebsiella pneumoniae isolates, four clonal groups (CG) or complexes (CC) prevailed: CG17 in France, CG101 in Italy, CG15 in Spain, and CC147 in Israel. ESBLs, mainly CTX-Ms, were produced by 226 isolates; three isolates expressed AmpC-like cephalosporinases. High genetic diversity of K. pneumoniae populations was observed, with specific characteristics at each center.

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.

We report four epidemiologically unrelated cases of KPC-carrying Klebsiella pneumoniae identified in Switzerland between May 2009 and November 2010. Three cases were transferred from Italy (two KPC-3, one KPC-2) and one from Greece (KPC-2). Resistance to colistin and doxycycline emerged in one KPC-3-carrying K. pneumoniae strain during therapy. These results demonstrate ongoing dissemination of KPC throughout Europe. Rapid and reliable identification of KPC and implementation of control measures is essential to limit spread.

We investigated the molecular epidemiology of gentamicin-resistant, extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae and Serratia marcescens, and risk factors associated with their acquisition in a neonatal intensive care unit (NICU) of a university hospital in Italy. During the study period (April-November 2004), S. marcescens was responsible for six infections and 31 colonisations, while K. pneumoniae was responsible for six infections and 103 colonisations. Concurrent isolation of both organisms occurred in 24 neonates. Molecular typing identified one major pulsed-field gel electrophoresis pattern each for S. marcescens and K. pneumoniae strains isolated during the study period. An 80 kb plasmid containing bla(SHV-12), bla(TEM-1) and aac(6')-Ib genes, isolated from both S. marcescens and K. pneumoniae strains, and showing identical restriction profiles, transferred resistance to third-generation cephalosporins to a previously susceptible Escherichia coli host. Birthweight, gestational age and use of invasive devices were significantly associated with S. marcescens and K. pneumoniae acquisition on univariate analysis, while empiric antimicrobial treatment with ampicillin and gentamicin, and duration of hospital stay, proved to be the only independent risk factors. In conclusion, conjugal plasmid transfer and empiric antimicrobial therapy with ampicillin and gentamicin might have contributed to the selection and spread of gentamicin-resistant ESBL-producing Enterobacteriaceae in the NICU.

The epidemiological features of 60 multiresistant K. pneumoniae strains isolated from 1991 to 1995 in a neonatal ward are described. Antibiotic. Susceptibility testing and plasmid profile analysis were used as subtyping procedures. Antibiotic susceptibility typing was not informative enough since discrimination among isolates was typically poor. Plasmid profile analysis demonstrated that 58 out of 60 strains harboured one or more plasmid DNA bands, of different molecular weights ranging between 1.8 and 150 Mda. Small plasmids were best visualized after the alkaline lysis procedure, while large plasmids by the Kado and Liu method. A combination of plasmid patterns obtained by the two extraction procedures was used to define the final plasmid profile for each strain. Thirteen different plasmid profiles were identified among the collection of K. pneumoniae isolates from newborn patients of the same intensive care unit. The investigation showed that the strains were not responsible for a single outbreak.