Integral genomic description of bla-harbouring plasmids recovered from Enterobacterales in Argentina.

Objective: To characterise four bla-harbouring plasmids recovered in Enterobacterales isolated in Argentina.

Methods: DNA was sequenced by Illumina and Oxford Nanopore Technologies, assembled using Unicycler, analysed using PlasmidFinder, MOB-Typer, IslandViewer4, and Resfinder, and visualised by Proksee and Clinker. bla-harbouring plasmids were compared with similar deposited plasmids using PLSDB.

Genomic characterization of carbapenemase-producing Klebsiella pneumoniae ST307 revealed multiple introductions in Buenos Aires, Argentina.

Objectives: To describe at genomic level nine carbapenemase-producing Klebsiella pneumoniae ST307 (Kp-ST307) clinical isolates recovered in Buenos Aires during 2017 to 2021, investigating their resistome, virulome, and phylogeny.

Methods: Antimicrobial susceptibility was determined according to Clinical and Laboratory Standards Intitute (CLSI). Genomic DNA was sequenced by Illumina MiSeq and analysed using SPAdes, PROKKA, and Kleborate.

Genetic and Biochemical Characterization of AXC-2 from .

spp. are intrinsically resistant to multiple antibiotics and can also acquire resistance to those commonly used for the treatment of respiratory infections, especially in patients with cystic fibrosis. The aim of this study was to perform the genetic and biochemical characterization of AXC-2 from and to analyze all available AXC variants.

Genomic characterization of bla-harbouring plasmids recovered from Pseudomonas aeruginosa.

Objectives: To the best of our knowledge, no genomic descriptions of bla-harbouring plasmids are available in literature so far. The aim of this study was to describe the genomic features of three bla-harbouring plasmids recovered from Pseudomonas aeruginosa isolated in Argentina in different periods.

Methods: bla-harbouring plasmids from three clinical P.

Molecular Mechanisms of Resistance to Ceftazidime/Avibactam in Clinical Isolates of and Pseudomonas aeruginosa in Latin American Hospitals.

Ceftazidime-avibactam (CZA) is the combination of a third-generation cephalosporin and a new non-β-lactam β-lactamase inhibitor capable of inactivating class A, C, and some D β-lactamases. From a collection of 2,727 clinical isolates of ( 2,235) and P. aeruginosa ( 492) that were collected between 2016 and 2017 from five Latin American countries, we investigated the molecular resistance mechanisms to CZA of 127 (18/2,235 [0.

Outbreak of Klebsiella pneumoniae ST11 Resistant To Ceftazidime-Avibactam Producing KPC-31 and the Novel Variant KPC-115 during COVID-19 Pandemic in Argentina.

We describe an outbreak of Klebsiella pneumoniae sequence type 11 (ST11) producing KPC variants resistant to ceftazidime-avibactam. Six patients hospitalized in the intensive care unit (mostly due to critical COVID pneumonia) presented infection or colonization by this bacterium. They had several comorbidities and required mechanical ventilation, central venous catheters, and urinary catheters.

Molecular mechanisms leading to ceftolozane/tazobactam resistance in clinical isolates of from five Latin American countries.

Objectives: Identify molecular mechanisms responsible for the non-susceptibility to ceftolozane/tazobactam (TOL) in a group of 158 clinical isolates of from five Latin American countries collected before the introduction of TOL into the clinical practice.

Methods: Clinical isolates of ( = 504) were collected between January 2016 and October 2017 from 20 hospitals located in Argentina, Brazil, Chile, Colombia, and Mexico. Minimum inhibitory concentrations (MICs) to TOL were determined by standard broth microdilution and interpreted according to CLSI breakpoints.

Comparative In Vitro Activity of Ceftolozane/Tazobactam against Clinical Isolates of and from Five Latin American Countries.

Background: Ceftolozane/tazobactam (C/T) is a combination of an antipseudomonal oxyiminoaminothiazolyl cephalosporin with potent in vitro activity against and tazobactam, a known β-lactamase inhibitor. The aim of this study was to evaluate the activity of C/T against clinical isolates of and collected from five Latin American countries between 2016 and 2017, before its clinical use in Latin America, and to compare it with the activity of other available broad-spectrum antimicrobial agents.

Methods: a total of 2760 clinical isolates (508 and 2252 ) were consecutively collected from 20 hospitals and susceptibility to C/T and comparator agents was tested and interpreted following the current guidelines.

Emergence and clonal expansion of Klebsiella pneumoniae ST307, simultaneously producing KPC-3 and NDM-1.

MDR Klebsiella pneumoniae ST307 is a high-risk clone, whose genetic features contribute to its adaptation to hospital environments and the human host. This study describes the emergence and clonal dissemination of K. pneumoniae ST307, recovered during November 2018 to February 2019 in a hospital in Buenos Aires city, which concurrently harbored KPC-3 and NDM-1.

Characterisation of blaharbouring plasmids recovered from Pseudomonas aeruginosa ST654 and ST235 high-risk clones.

Objective: The main objectives were to describe two bla plasmids recovered from Pseudomonas aeruginosa isolates belonging to the ST654 and ST235 high-risk clones, and to compare with complete sequences of bla harbouring plasmids available in public databases.

Methods: Antimicrobial susceptibility was determined according to CLSI (Clinical and Laboratory Standards Institute) guidelines. Genomes were sequenced using an Illumina MiSeq platform, and bla plasmid sequences were achieved using MinION platform.

Report of two events of nosocomial outbreak and pseudo-outbreak due to contamination with Achromobacter spp.

Achromobacter spp. are increasingly recognized as emerging pathogens in immunocompromised patients or suffering cystic fibrosis, but unusual in immunocompetent hosts or individuals that underwent surgery. In this study we describe two simultaneous events attributable to two different Achromobacter spp.

Expansion and improvement of MALDI-TOF MS databases for accurate identification of Achromobacter species.

Different MALDI-TOF MS databases were evaluated for the identification of Achromobacter species. The in-house and extended database generated in this study rendered more accurate identification (58/64 and 57/64 isolates, respectively) in comparison with the Bruker commercial database (42/64 isolates), especially in those infrequent species that are not available or poorly represented.

In Vitro Susceptibility to Ceftazidime/Avibactam and Comparators in Clinical Isolates of Enterobacterales from Five Latin American Countries.

: High rates of resistance to third-generation cephalosporins and carbapenems in Enterobacterales have been reported in Latin America. Ceftazidime/avibactam (CZA) is the combination of a third-generation cephalosporin and a non-β-lactam β-lactamase inhibitor, which has shown activity against isolates producing class A, C and D β-lactamases. Herein, we evaluated the activity of CZA and comparators against clinical isolates of Enterobacterales in Latin America.

Full characterization of an IncR plasmid harboring qnrS1 recovered from a VIM-11-producing Pseudomonas aeruginosa.

Metallo-β-lactamases (MBL) producing Pseudomonas aeruginosa isolates have been well characterized. Quinolones are commonly used in the treatment of carbapenem-resistant P. aeruginosa infections; however, data about PMQR in this species are scarce.

Diversity of Achromobacter species recovered from patients with cystic fibrosis, in Argentina.

Different phenotype-based techniques and molecular tools were used to describe the distribution of different Achromobacter species in patients with cystic fibrosis (CF) in Argentina, and to evaluate their antibiotic resistance profile. Phenotypic identification was performed by conventional biochemical tests, commercial galleries and MALDI-TOF MS. Genetic approaches included the detection of A.

Changing epidemiology of KPC-producing Klebsiella pneumoniae in Argentina: Emergence of hypermucoviscous ST25 and high-risk clone ST307.

Objectives: To assess the epidemiological features of 76 Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) isolates recovered from three hospitals in Buenos Aires, Argentina, during 2015-2017.

Methods: Antimicrobial susceptibilities were determined according to CLSI Clinical and Laboratoy Standards guidelines. Molecular typing of KPC-Kp was performed by pulsed-field gel electrophoresis (PFGE)-Xbal and multilocus sequence typing.

MALDI-TOF MS based procedure to detect KPC-2 directly from positive blood culture bottles and colonies.

In this study, we identified specific carbapenemase-producing isolates applying an easy and rapid protocol for the detection of mature KPC-2 β-lactamase by MALDI-TOF MS from colony and positive blood culture bottles. In addition, we evaluated the correlation of the ~11,109 Da signal as a biomarker associated with KPC-2 production. A collection of 126 well-characterized clinical isolates were evaluated (including 60 KPC-2-producing strains).

Spread of Clonally Related Escherichia coli Strains Harboring an IncA/C Plasmid Encoding IMP-8 and Its Recruitment into an Unrelated MCR-1-Containing Isolate.

Ten IMP-8-producing isolates were recovered from surveillance cultures of a neonatal intensive care unit; eight of the isolates were clonally related. A 168.2-kb plasmid was fully sequenced, and it corresponded to the recently described IncA/C1-ST13 plasmid.

Characterisation of OXA-258 enzymes and AxyABM efflux pump in Achromobacter ruhlandii.

Objectives: The aim of this study was to characterise OXA-258 variants and other features that may contribute to carbapenem resistance in Achromobacter ruhlandii.

Methods: Kinetic parameters for purified OXA-258a and OXA-258b were determined measuring the rate of hydrolysis of a representative group of antimicrobial agents. Whole-genome shotgun sequencing was performed on A.

Fast and easy detection of CMY-2 in Escherichia coli by direct MALDI-TOF mass spectrometry.

Fast typing methods for third generation cephalosporin resistance mechanisms are needed to guide appropriate treatment and prevent potential dissemination events. In this study we used a novel short and fast methodology for the identification of CMY-2 in 50 well characterized clinical isolates of E. coli by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry- MALDI-TOF MS.

Detection and molecular characterization of Clostridium difficile ST 1 in Buenos Aires, Argentina.

Thirty one C. difficile isolates recovered in 2015 were characterized. Nineteen/31 were positive for tcdA/B, among them, 4 isolates were also positive for CDT coding genes.

Identification of CfiA coding genes in Bacteroides fragilis isolates recovered in Argentina. Inconsistencies in CfiA organization and nomenclature.

CfiA (CcrA) metallo-β-lactamase is the main carbapenem resistance mechanism in B. fragilis. From cfiA positive isolates detected in a previous surveillance study, 3 displayed resistance to imipenem while the remaining were susceptible.

Biotransformation of chromium (VI) in liquid effluents by resistant bacteria isolated from the Matanza-Riachuelo basin, in Argentina.

The aims of this investigation were to evaluate the bacterial resistance to zinc, copper, chromium (VI) and lead in surface water streams from Buenos Aires, Argentina; to select a chromium-resistant strain able to remove the metal in batch process and to evaluate the potential of this strain to remove chromium (VI) in liquid effluents. Bacterial resistance to the metals was evaluated by determining the minimal inhibitory concentration. The kinetic of chromium (VI) removal by one of the resistant strains was studied in nutrient broth with 50 and 100 mg L of the metal, as well as an effluent from an electroplating industry.