Characterization of carbapenemase-producing Serratia marcescens and whole-genome sequencing for plasmid typing in a hospital in Madrid, Spain (2016-18).

Carbapenemase-producing Enterobacterales (CPE) are increasingly recognized in nosocomial infections, also affecting ICU patients. We aimed to characterize the carbapenemase-producing Serratia marcescens (CPSm) isolates recovered in our hospital in Madrid (Spain) between March 2016 and December 2018. Overall, 50 isolates from clinical and epidemiological surveillance samples were recovered from 24 patients admitted to the medical ICU and 10 non-ICU-related patients based on their phenotypic resistance. Carbapenemase characterization, antibiotic susceptibility, PFGE clonal relatedness, plasmid characterization, WGS (Illumina-NovaSeq 6000) and phylogenetic analysis were performed. A single isolate was finally considered for each patient, except for Patient 8 that was colonized by two different isolates (n = 35). Isolates were characterized as VIM-1 (n = 29) or OXA-48 producers (n = 6). Up to seven genetic lineages were found by PFGE, with dominance of two clones. Plasmid characterization confirmed that almost all CPSm carried the same ∼60 kb IncL OXA-48- or VIM-1-encoding plasmid, which was related to the globally disseminated IncL-pOXA-48a. WGS allowed plasmid reconstruction with two variants: IncL-pVIM-1 (∼65 kb) and IncL-pOXA-48 (∼62 kb). blaOXA-48-Tn1999 (∼5 kb) was the unique antibiotic resistance gene in pOXA-48, whereas pVIM-1 plasmids (∼8 kb) harboured a class 1 integron containing 5'-blaVIM-1+aacA4+dfrB1+aadA1+catB2+qacEDelta1+sul1-3'. Our results confirm the dissemination of CPSm within our institution in both ICU and non-ICU environments, representing two prevalent CPSm clones, and the same IncL-pOXA-48 plasmid previously described in other Enterobacterales, but containing the blaVIM-1 gene. This also reinforces the relevance of species different from Klebsiella pneumoniae or Escherichia coli in the CPE landscape and circulating lineages and plasmids in local CPE epidemiology.

Pérez-Viso B ，Hernández-García M ，Ponce-Alonso M ，Morosini MI ，Ruiz-Garbajosa P ，Del Campo R ，Cantón R ... -  《-》

First Report of an OXA-48- and CTX-M-213-Producing Kluyvera Species Clone Recovered from Patients Admitted in a University Hospital in Madrid, Spain.

Enterobacterales species other than Klebsiella pneumoniae also contribute to OXA-48 carbapenemase endemicity. We studied the emergence of an OXA-48-producing Kluyvera species clone, which expresses the novel CTX-M-213 enzyme, colonizing patients in our hospital. Rectal swabs from patients admitted in four wards (March 2014 to March 2016; R-GNOSIS project) were seeded onto Chromo ID-ESBL) and Chrom-CARB/OXA-48 chromogenic agar plates. Carbapenemases and extended-spectrum β-lactamases (ESBLs) were characterized (PCR, sequencing, cloning, and site-directed mutagenesis), and antibiotic susceptibility was determined. Clonal relatedness was established (XbaI pulsed-field gel electrophoresis [XbaI-PFGE]), and plasmid content was studied (transformation, S1 nuclease digestion-PFGE, SB-hybridization, restriction fragment length polymorphism [RFLP] analysis [DraI and HpaI], and PCR [incompatibility group and repA, traU, and parA genes]). Whole-genome sequencing (WGS) (Illumina HiSeq-2500) and further bioinformatics analysis of plasmids (PLACNET and plasmidSPAdes) were performed. Patients' charts were reviewed. Six unrelated patients (median age, 75 years [range, 59 to 81 years]; 4/6 male patients) colonized with OXA-48-producing Kluyvera species isolates (>95% similarity of the PFGE pattern) were identified. Nosocomial acquisition was demonstrated. In two patients, OXA-48-producing Kluyvera species isolates coexisted with OXA-48-producing Raoultella ornithinolytica, K. pneumoniae, and Escherichia coli The blaOXA-48 gene was located on an ∼60-kb IncL plasmid related to IncL/M-pOXA-48a and the novel blaCTX-M-213 gene in a conserved chromosomal region of Kluyvera species isolates. CTX-M-213, different from CTX-M-13 (K56E) but conferring a similar β-lactam resistance profile, was identified. Genomic analysis also revealed a 177-kb IncF plasmid (class I integron harboring sul1 and aadA2) and an 8-kb IncQ plasmid (IS4-blaFOX-8). We describe the first blaOXA-48 plasmid in Kluyvera spp. and the novel chromosomal CTX-M-213 enzyme and highlight further nosocomial dissemination of blaOXA-48 through clonal lineages or plasmids related to IncL/M-pOXA-48a.

Hernández-García M ，León-Sampedro R ，Pérez-Viso B ，Morosini MI ，López-Fresneña N ，Díaz-Agero C ，Coque TM ，Ruiz-Garbajosa P ，Cantón R ... -  《-》

Early OXA-48-Producing Enterobacterales Isolates Recovered in a Spanish Hospital Reveal a Complex Introduction Dominated by Sequence Type 11 (ST11) and ST405 Klebsiella pneumoniae Clones.

Carbapenemase-producing Enterobacterales (CPE) have become an important public health concern. In our hospital, VIM enzymes were first detected in 2005, Klebsiella pneumoniae carbapenemase (KPC) enzymes in 2009, and OXA-48 enzymes in 2012. We assess the population biology of the first OXA-48-producing Enterobacterales isolates recovered in our hospital (2012 to 2013) where infections by other carbapenemases had been endemic for several years. Over a 21-month period, 71 isolates (61 Klebsiella pneumoniae, 5 Escherichia coli, 2 Klebsiella aerogenes, and 1 each of Enterobacter cloacae, Klebsiella oxytoca, and Citrobacter amalonaticus) recovered from clinical and surveillance specimens from 57 patients (22.8% nonhospitalized) were investigated for OXA-48-like-producing enzymes. Analyses for characterization and determination of the location of the blaOXA-48 gene, plasmid transferability, sequence, and clonal relatedness were performed. Most of the isolates also coproduced CTX-M-15 (57/71, 80.3%) and/or VIM-1 (7/71, 9.8%). K. pneumoniae was predominantly identified as sequence type 11 (ST11) (63.4%) and ST405 (9.8%) and E. coli as ST540, ST1406, ST3163, and ST4301. The blaOXA-48 gene was part of Tn1999.2 located at the tir gene of plasmids (ca. ≥50 kb) of the IncL/M group, also carrying blaVIM-1 and blaCTX-M-15 genes. We selected one ST11 K. pneumoniae isolate for whole-genome sequencing in which we studied the plasmid containing the blaOXA-48 gene. This plasmid was compared with indexed plasmids existing in NCBI database by the use of BRIG and MAUVE. Our data suggest a rapid spread of blaOXA-48 genes between commonly isolated high-risk clones of Enterobacterales species, frequently associated with antibiotic resistance. Moreover, the emergence of the multiresistant ST11 K. pneumoniae clone among nonhospitalized patients emphasizes the difficulty of preventing its dissemination into the community.IMPORTANCE We present results of microbiological analysis of the first Enterobacterales isolates that were isolated in 2012 in our institution expressing OXA-48 carbapenemase. This enzyme confers resistance to carbapenems, an important group of antibiotics widely used in the hospitals. OXA-48 carbapenemase is currently present in many parts of the world, but it is found particularly frequently in the Mediterranean area. It was disseminated at the Ramón y Cajal Hospital and found to be associated with a particular Klebsiella pneumoniae strain, so-called high-risk clone ST11, which was previously found in our institution in association with other enzymes such as CTX-M-15, VIM-1, and KPC-3. This clone might have acquired a plasmid harboring the blaOXA-48 gene. Our results point out the importance of local epidemiology in the dissemination and maintenance of multidrug-resistant bacteria.

Gijón D ，Tedim AP ，Valverde A ，Rodríguez I ，Morosini MI ，Coque TM ，Manrique M ，Pareja E ，Tobes R ，Ruiz-Garbajosa P ，Cantón R ... -  《mSphere》

A single-day point-prevalence study of faecal carriers in long-term care hospitals in Madrid (Spain) depicts a complex clonal and polyclonal dissemination of carbapenemase-producing Enterobacteriaceae.

The objective of this study was to describe the prevalence and microbiological characteristics of carbapenemase-producing Enterobacteriaceae (CPE) colonizing patients in long-term care hospitals (LTCHs) in Madrid, Spain. Three LTCHs were included in a single-day point-prevalence survey (September 2013). Rectal swabs, collected from all hospitalized patients (137 in LTCH-A, 121 in LTCH-B and 83 in LTCH-C), were plated onto chromogenic media. Population structure (PFGE and MLST), genes encoding carbapenemases and ESBLs and plasmids carrying carbapenemase genes were characterized. The prevalence of CPE carriers was 4.1% (14/341) [2.9% (4/137), LTCH-A; 4.1% (5/121), LTCH-B; and 6.0% (5/83), LTCH-C]. OXA-48 was the most prevalent carbapenemase (nine Klebsiella pneumoniae, two Escherichia coli, one Enterobacter cloacae and one Citrobacter braakii) followed by VIM-1 (one K. pneumoniae and one Raoultella ornithinolytica). One patient (LTCH-C) was co-colonized with OXA-48-producing K. pneumoniae and E. coli. K. pneumoniae and E. coli isolates also coproduced CTX-M-15 (n = 11) or CTX-M-9 (n = 1) enzymes. K. pneumoniae clustered into six PFGE types corresponding to ST11 (n = 1), ST15 (n = 6), ST307 (n = 1) and ST405 (n = 2). E. coli from LTCH-A and LTCH-C exhibited two different PFGE types associated with ST68. OXA-48 and VIM-1 enzymes were found in different clones in LTCH-A and LTCH-C. However, OXA-48 was the only carbapenemase detected in LTCH-B, mainly associated with K. pneumoniae ST15. KPC, IMP and NDM enzymes were not detected. blaOXA-48 was located on an ∼ 60 kb plasmid with a pOXA-48a-IncL/M backbone. We describe the first point-prevalence study of CPE faecal carriers in LTCHs in Spain. OXA-48, the most prevalent carbapenemase, showed a complex dissemination pattern with clonal and polyclonal bacterial populations.

Ruiz-Garbajosa P ，Hernández-García M ，Beatobe L ，Tato M ，Méndez MI ，Grandal M ，Aranzábal L ，Alonso S ，Lópaz MÁ ，Astray J ，Cantón R ... -  《-》

The ICU environment contributes to the endemicity of the "Serratia marcescens complex" in the hospital setting.

Aracil-Gisbert S ，Fernández-De-Bobadilla MD ，Guerra-Pinto N ，Serrano-Calleja S ，Pérez-Cobas AE ，Soriano C ，de Pablo R ，Lanza VF ，Pérez-Viso B ，Reuters S ，Hasman H ，Cantón R ，Baquero F ，Coque TM ... -  《-》