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Carbapenemase production is constantly increasing among different Enterobacterales species. We analyzed the microbiological characteristics and population structure of all carbapenemase-producing Enterobacter spp. (CP-Ent) isolates recovered at the Ramón y Cajal Hospital between 2005 and 2018. Overall, 178 CP-Ent isolates (60.7% colonization, 39.3% clinical) were recovered from 165 hospitalized patients (165/176, 93.7%; medical [102/165], surgical [34/165], and intensive care unit [29/165] areas), emergency unit (4/176, 2.3%), and ambulatory patients (7/176, 4.0%). In addition, three CP-Ent were found in environmental sources. Clinical samples were mainly urine (37.1%). The most frequent matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-identified species were Enterobacter cloacae (n = 85) and Enterobacter asburiae (n = 49). hsp60 gene sequencing showed a higher species diversity than MALDI-TOF: 70 Enterobacter hormaechei-clusters III, VI, VIII; 69 Enterobacter roggenkampii-IV; 15 Enterobacter kobei-II; 9 E. asburiae-I; 3 Enterobacter ludwigii-V; and 1 E. cloacae subsp. dissolvens-XII. Nine Klebsiella aerogenes were also identified. Overall, a high clonal diversity (Simpson Diversity Index >0.90) was found among CP-Ent-clusters. Environmental isolates were clonally related to clinical ones. Amikacin and tigecycline showed the highest susceptibility (>93%). VIM-1 (n = 133/181, 73.5%) and OXA-48 (n = 34/181, 18.8%) carbapenemases were predominant, followed by KPC-2 (n = 9/181, 5.0%), KPC-3 (n = 2/181, 1.1%), VIM-2 (n = 1/181, 0.6%), and two coproducers (VIM-1+KPC-2 and VIM-1+KPC-3). Extended-spectrum beta-lactamase (ESBL) coproduction (14.4%) emerged in 2012, mainly associated with blaSHV-12 (p < 0.001), E. roggenkampii (p < 0.001), and colonization (p = 0.03). VIM-1- and OXA-48-CP-Ent fecal carriers increased in our hospital, particularly between 2011 and 2018 (p < 0.001). Moreover, KPC and OXA-48 producers emerged in 2010 and 2012, respectively. They superimposed over VIM producers, which were persistently recovered since first detection in 2005. These results depict increased complexity over time of CP-Ent. [ABSTRACT FROM AUTHOR]

The global success of multidrug-resistant Acinetobacter baumannii has been associated with the dissemination of a high-risk clone designated clonal complex (CC) 92B (Bartual scheme)/CC2P (Pasteur scheme), which is the most frequent genetic lineage in European, Asian, and North American carbapenem-resistant Acinetobacter isolates. In these isolates, carbapenem resistance is mainly mediated by β-lactamases encoded by blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, and/or blaOXA-58-like genes. In this study, we characterized the population genetics of 121 carbapenem-resistant A. baumannii complex isolates recovered from 14 hospitals in seven cities in Colombia (2008-2010). Multiplex PCR was used to detect blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, and blaOXA-58-like genes. Molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). PCR showed that 118 (97.5%) of the isolates were positive for both blaOXA-23-like and blaOXA-51-like genes, and three other isolates were only positive for blaOXA-51-like. PFGE identified 18 different pulsotypes, while MLST identified 11 different sequence types (STs), seven of which had not been previously described in Acinetobacter. None of the STs found in this study was associated with CC92B/CC2P. The most widespread STs in our isolates belonged to ST636 and their single-locus variants ST121/ST124/ST634 (CC636B) followed by STs belonging to CC110B. Our observations suggest a wide distribution of diverse A . baumannii complex clones containing blaOXA-23-like in Colombian hospitals (especially CC636B and CC110B) that differ from the high-risk clones commonly found in other regions of the world, indicating a distinct molecular epidemiology of carbapenem-resistant Acinetobacter spp. in Colombia. [ABSTRACT FROM AUTHOR]

The role of wild animals, particularly migratory birds, in the dissemination of antibiotic-resistant bacteria between geographically distant ecosystems is usually underestimated. The aim of this work was to characterize the Escherichia coli population from Franklin's gull feces, focusing on the extended-spectrum β-lactamase (ESBL)-producing strains. In the summer of 2011, 124 fecal swabs from seagulls (1 of each) migrating from the United States and Canada to the coast of Antofagasta, north of Chile, were collected. Samples were seeded on MacConkey agar supplemented with 2 μg/ml of cefotaxime and a single colony from each plate was tested for ESBL production by the double-disk ESBL synergy test. Antibiotic susceptibility was determined by the disk diffusion method and blaESBL genes were amplified and sequenced. The genetic diversity of isolates was explored by pulsed-field gel electrophoresis (PFGE)- XbaI and multilocus sequence typing. A total of 91 E. coli isolates with high rates of antibiotic resistance were identified. Carbapenemase production was not detected, whereas 67 of the 91 (54%) isolates exhibited an ESBL phenotype due to the presence of CTX-M-15 (61.3%), CTX-M-2 (19.3%), CTX-M-22 (16.1%), and CTX-M-3 (1.6%) coding genes. High genetic diversity was observed, with 30 PFGE patterns and 23 sequence types (STs), including ST131 (18%), ST44 (15%), ST617 (9%), and ST10 (9%). Results presented here are complementary to those previously reported by Hernández et al. in the same gull species, but located in the Central Region of Chile. Differences observed between gulls from both areas lead us to hypothesize that gulls from the northern location retain, as gut carriers, those resistant bacteria acquired in the United States and/or Canada. [ABSTRACT FROM AUTHOR]

This work summarized the results obtained in an institutional Klebsiella pneumoniae surveillance program recently implemented in Cuba. Eighteen hospitals from five regions provided a total of 228 K. pneumoniae isolates (164 from admitted patients, four from hospital environmental sources, and 60 isolates from community patients). The genetic relationship was assessed by pulsed-field gel electrophoresis and multilocus sequence typing. Antimicrobial susceptibility was determined by the agar dilution method, and blaESBL genes were sequenced. Fifty four K. pneumoniae isolates were extended-spectrum β-lactamases (ESBL)-producers (23.6%), mostly due to the CTX-M-15 enzyme (79.6%). ESBL isolates were grouped in 27 different sequence types (STs), being the most prevalent ST15 (15%), ST152 (13%), and both ST48 and ST147 (11%, respectively). Community-acquired criteria could be demonstrated in 60 patients (26%) corresponding to urological (33%), wound (27%), respiratory (27%), and otic (13%) infections. Population structure analysis showed that our isolates corresponded to a highly polyclonal population with 10 nonpreviously described STs, demonstrating the importance of local epidemiological studies. We report the first data of the population structure of ESBL-producing K. pneumoniae isolates obtained in a national multicenter surveillance Cuban program. Results showed that a highly polyclonal ESBL-producer K. pneumoniae population was mainly due to CTX-M-15 carriage, whereas carbapenemases production was not present. [ABSTRACT FROM AUTHOR]

We report the emergence and long-lasting persistence of linezolid resistance in an ampicillin-resistant Enterococcus faecium strain in the intestine of a neutropenic oncohematologic patient receiving chemotherapy. The patient was first colonized by an epidemic ampicillin-resistant E. faecium (ARE)-ST117 clustering into lineage 78. This clone exhibited resistance to levofloxacin, erythromycin and high-level resistance to streptomycin and gentamicin. After receiving treatment with several broad spectrum antibiotics for febrile neutropenia, a 9-day course of oral linezolid was administered once the patient developed bacteraemia by the same ARE colonizing clone. Linezolid-resistant ARE was detected 17 days later in the follow-up fecal samples and persisted 41 days after suppression of linezolid therapy. Resistance to linezolid was associated with G2576T transversion in the 23S rRNA and the presence of cfr gene was not detected. The persistence of G2576T-ARE strains, especially in oncohematologic patients with injured intestinal membranes, could increase the risk of bacteraemia. [ABSTRACT FROM AUTHOR]