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Resistance to carbapenems in Klebsiellapneumoniae has been mostly related with the worldwide dissemination of KPC, largely due to the pandemic clones belonging to the complex clonal (CC) 258. To unravel blaKPC post-endemic clinical impact, here we describe clinical characteristics of 68 patients from a high complexity hospital, and the molecular and genetic characteristics of their 139 blaKPC—K.pneumoniae (KPC-Kp) isolates. Of the 26 patients that presented relapses or reinfections, 16 had changes in the resistance profiles of the isolates recovered from the recurrent episodes. In respect to the genetic diversity of KPC-Kp isolates, PFGE revealed 45 different clonal complexes (CC). MLST for 12 representative clones showed ST258 was present in the most frequent CC (23.0%), however, remaining 11 representative clones belonged to non-CC258 STs (77.0%). Interestingly, 16 patients presented within-patient genetic diversity of KPC-Kp clones. In one of these, three unrelated KPC-Kp clones (ST258, ST504, and ST846) and a blaKPC—K.variicola isolate (ST182) were identified. For this patient, complete genome sequence of one representative isolate of each clone was determined. In K.pneumoniae isolates blaKPC was mobilized by two Tn3-like unrelated platforms: Tn4401b (ST258) and Tn6454 (ST504 and ST846), a new NTEKPC-IIe transposon for first time characterized also determined in the K.variicola isolate of this study. Genome analysis showed these transposons were harbored in different unrelated but previously reported plasmids and in the chromosome of a K.pneumoniae (for Tn4401b). In conclusion, in the blaKPC post-endemic dissemination in Colombia, different KPC-Kp clones (mostly non-CC258) have emerged due to integration of the single blaKPC gene in new genetic platforms. This work also shows the intra-patient resistant and genetic diversity of KPC-Kp isolates. This circulation dynamic could impact the effectiveness of long-term treatments. [ABSTRACT FROM AUTHOR]

Bacteria that produce the broad-spectrum Carbapenem antibiotic NewDelhi Metallo-b-lactamase (NDM) place a burden on health care systems worldwide, due to the limited treatment options for infections caused by them and the rapid global spread of this antibiotic resistancemechanism. Although it is believed that theassociated resistancegene blaNDM-1 originated in Acinetobacter spp., the role of Enterobacteriaceae in its dissemination remains unclear. In this study, we usedwhole genome sequencing to investigate the dissemination dynamics of blaNDM-1-positive plasmids in a set of 21 clinical NDM-1-positive isolates from Colombia and Mexico (Providencia rettgeri, Klebsiella pneumoniae, andAcinetobacter baumannii) aswell as six representativeNDM-1-positive Escherichia coli transconjugants. Additionally, the plasmids from three representative P. rettgeri isolates were sequenced by PacBio sequencing and finished. Our results demonstrate the presence of previously reported plasmids from K. pneumoniae and A. baumannii in different genetic backgrounds and geographically distant locations in Colombia. Three new previously unclassified plasmids were also identified in P. rettgeri from Colombia and Mexico, plus an interesting genetic link between NDM-1-positive P. rettgeri from distant geographic locations (Canada, Mexico, Colombia, and Israel) without any reported epidemiological links was discovered. Finally, we detected a relationship between plasmids present in P. rettgeri and plasmids from A. baumannii and K. pneumoniae. Overall, our findings suggest a Russian dollmodel for the dissemination of blaNDM-1 in LatinAmerica, with P. rettgeri playing a central role in this process, andrevealnewinsights into the evolution and disseminationof plasmids carrying such antibiotic resistance genes. [ABSTRACT FROM AUTHOR]

Background: Community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) clones are a global concern due to their resistance and increased virulence and their ability to cause infections both hospitalized patients and healthy people in the community. Here, we characterize 32 isolates of a new CG-MRSA clone. These isolates were identified in four cities in Colombia, South America.Methods: The isolates were recovered from four different epidemiological and prospective studies that were conducted in several regions of Colombia. Molecular characterizations included multilocus sequence typing; pulsed-field gel electrophoresis; SCCmec, agr and spa typing; and whole-genome sequencing.Results: All isolates belonged to ST923 (clonal complex 8), harbouring SCCmec IVa and a spa type t1635 and lacking an arginine catabolism mobile element. The isolates were classified as COL923, were resistant to at least one non-beta-lactam antibiotic, and exhibited high frequencies (>60%) of resistance to macrolides and tetracycline. Using whole-genome sequencing, we found that this new clone harbours novel prophage 3 and beta-island structures and a slightly different pathogenicity island 5. Moreover, isolates belonging to the COL923 clone are grouped in a different clade than USA300 and USA300-LV.Conclusion: Our results show the emergence and spread of the COL923 clone in different cities in Colombia. This clone is resistant to several antibiotics and possesses new structures in its mobile genetic elements. [ABSTRACT FROM AUTHOR]

In recent decades, antimicrobial resistance (AMR) has led to an increased use of therapeutic alternatives. Among these options, colistin continues to be an option for the treatment of multi-resistant (MDR) Gram-negative bacterial infections. However, due to its high toxicity (nephrotoxicity and neurotoxicity) and narrow therapeutic window, colistin treatment must be utilized carefully. Colistin-treated patients have been observed to have higher mortality due to inadequate therapeutic levels. The objective of this study was to estimate the difference in colistin plasma levels in critically ill patients, and its relationship to favorable or unfavorable clinical outcomes. This prospective observational study was conducted between September 2017 and June 2020 at the Universidad de La Sabana Clinic, in patients who had been treated with colistimethate sodium (CMS) for at least 72 h until day 7 of drug treatment in the critical care unit of a university hospital. There were no statistically significant differences in colistin levels between groups with favorable or unfavorable clinical outcomes (0.16 SD vs. 0.54 SD p-value = 0.167). There was higher mortality in patients with subtherapeutic levels (18% vs. 0%), and additionally, there was a greater rate of renal failure in the group with higher therapeutic levels (50% vs. 20.7%). Due to the loss of power of the study, we were unable to demonstrate a possible difference between colistin levels related to favorable or unfavorable clinical outcomes at day 7. However, we recommend further studies to evaluate the impact of measuring levels in terms of mortality and security. [ABSTRACT FROM AUTHOR]

The carbapenemase OXA-244 is a derivate of OXA-48, and its detection is very difficult in laboratories. Here, we report the identification and genomic analysis of an Escherichia coli isolate (28Eco12) harboring the blaOXA-244 gene identified in Colombia, South America. The 28Eco12 isolate was identified during a retrospective study, and it was recovered from a patient treated in Colombia. The complete nucleotide sequence was established using the PacBio platform. A comparative genomics analysis with other blaOXA-244–harboring Escherichia coli strains was performed. The 28Eco12 isolate belonged to sequence type (ST) 38, and its genome was composed of two molecules, a chromosome of 5,343,367 bp and a plasmid of 92,027 bp, which belonged to the incompatibility group IncY and did not harbor resistance genes. The blaOXA-244 gene was chromosomally encoded and mobilized by an ISR1-related Tn6237 composite transposon. Notably, this transposon was inserted and located within a new genomic island. To our knowledge, this is the first report of a blaOXA-244–harboring Escherichia coli isolate in America. Our results suggest that the introduction of the OXA-244-producing E. coli isolate was through clonal expansion of the ST38 pandemic clone. Other isolates producing OXA-244 could be circulating silently in America. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa, a bacterium commonly isolated from hospital settings, exhibits intrinsic resistance to a number of antibiotics and can acquire resistance during antibiotic therapy. Resistance towards carbapenems is increasing due to its overuse in the treatment of infections caused by extended-spectrum β-lactamase (ESBL) producing organisms. Nonetheless, carbapenems are essential for the treatment of high-risk infections and are one of the remaining weapons in the fight against "extreme drug resistance" of Gram-negative/positive bacilli. Herein, we describe a case report of infections caused by P. aeruginosa strains that carry blaVIM-2 and blaKPC-2 carbapenemase genes simultaneously, identified in five patients who were admitted to a high complexity health institution in Colombia. Molecular characterization included PCR screening for blaKPC, blaGES, blaOXA-48, blaIMP, blaNDM, and blaVIM carbapenemase and other resistance genes as well as analysis of the genetic relationships by genome macro-restriction and Pulsed-Field Gel Electrophoresis (PFGE) separation. In conclusion, these infections represent a major challenge to public health due to the risk of the infection spreading compounded by the fact that limited treatment options are available, thereby increasing the risk of increased morbidity and mortality. [ABSTRACT FROM AUTHOR]

Our aim was identify of the pandemic B2-ST131 Escherichia coli clone by to the Institute Pasteur and Achtman scheme, and investigate the resistance profile phenotypic-genotypic, with identification of class 1 integron. Of thirty-five ESBL-producing isolates recovered of patients with diagnosis of urinary tract infections (UTI), six E. coli strains serotype O25 were identified with resistance antimicrobial to several groups of antibiotics such as broad-spectrum cephalosporins, fluoroquinolones and aminoglycosides, harboring blaSHV, blaCTX-M genes in all isolates and blaTEM in two isolates. Sequencing of blaCTX-M revealed CTX-M-15 in all strains. The PMQR aac(6´)-Ib-cr and qnrB19 genes were presented in five and four isolates respectively, AMEs genes aac(6´)-Ib and aac(3)-IIa were presented in strain amikacin-gentamicin-resistant. Sequencing of the variable regions of the class 1 integron revealed dfrA and aadA genes cassette. The analysis of multilocus sequence typing (MLST) confirms the presence of the pandemic B2-ST131 E. coli clone by Achtman scheme in all ST43 isolates obtained by of the Institute Pasteur scheme. The results presented herein, reveal the presence of B2-ST131 E. coli clone in Ecuador, disseminated in hospitals and community settings. [ABSTRACT FROM AUTHOR]

We report the draft genome of a clinical multi-resistant Klebsiella pneumoniae (24Kpn33) isolate, whose genome (5.7 Mbp) harbored 17 antibiotic resistance genes, including bla KPC-2 . Notably, this gene was mobilized within the IncP-6 pCOL-1 plasmid, the first genetic platform related to the acquisition and dissemination of the bla KPC-2 in Pseudomonas aeruginosa ., Competing Interests: The authors declare no conflict of interest.

The carbapenemase OXA-244 is a derivate of OXA-48, and its detection is very difficult in laboratories. Here, we report the identification and genomic analysis of an Escherichia coli isolate (28Eco12) harboring the bla OXA-244 gene identified in Colombia, South America. The 28Eco12 isolate was identified during a retrospective study, and it was recovered from a patient treated in Colombia. The complete nucleotide sequence was established using the PacBio platform. A comparative genomics analysis with other bla OXA-244 -harboring Escherichia coli strains was performed. The 28Eco12 isolate belonged to sequence type (ST) 38, and its genome was composed of two molecules, a chromosome of 5,343,367 bp and a plasmid of 92,027 bp, which belonged to the incompatibility group IncY and did not harbor resistance genes. The bla OXA-244 gene was chromosomally encoded and mobilized by an ISR1-related Tn 6237 composite transposon. Notably, this transposon was inserted and located within a new genomic island. To our knowledge, this is the first report of a bla OXA-244 -harboring Escherichia coli isolate in America. Our results suggest that the introduction of the OXA-244-producing E. coli isolate was through clonal expansion of the ST38 pandemic clone. Other isolates producing OXA-244 could be circulating silently in America.

Providencia rettgeri is an opportunistic bacterial pathogen of clinical significance due to its association with urinary tract infections and multidrug resistance. Here, we report the first complete genome sequence of P. rettgeri The genome of strain RB151 consists of a 4.8-Mbp chromosome and a 108-kbp bla NDM-1 -positive plasmid., (Copyright © 2017 Marquez-Ortiz et al.)