Automatic Discrimination of Species within the Enterobacter cloacae Complex Using Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Supervised Algorithms.

The Enterobacter cloacae complex (ECC) encompasses heterogeneous clusters of species that have been associated with nosocomial outbreaks. These species may have different acquired antimicrobial resistance and virulence mechanisms, and their identification is challenging. This study aims to develop predictive models based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) profiles and machine learning for species-level identification.

Outbreak by KPC-62-producing ST307 Klebsiella pneumoniae isolates resistant to ceftazidime/avibactam and cefiderocol in a university hospital in Madrid, Spain.

Objectives: Ceftazidime/avibactam and cefiderocol are two of the latest antibiotics with activity against a wide variety of Gram-negatives, including carbapenem-resistant Enterobacterales. We sought to describe the phenotypic and genotypic characteristics of ceftazidime/avibactam- and cefiderocol-resistant KPC-Klebsiella pneumoniae (KPC-Kp) detected during an outbreak in 2020 in the medical ICU of our hospital.

Methods: We collected 11 KPC-Kp isolates (6 clinical; 5 surveillance samples) resistant to ceftazidime/avibactam and cefiderocol from four ICU patients (November 2020 to January 2021), without prior exposure to these agents.

The Impact of Colistin Resistance on the Activation of Innate Immunity by Lipopolysaccharide Modification.

Colistin resistance is acquired by different lipopolysaccharide (LPS) modifications. We proposed to evaluate the of effect colistin resistance acquisition on the innate immune response. We used a pair of ST11 clone Klebsiella pneumoniae strains: an OXA-48, CTX-M-15 K.

Time kill-assays of antibiotic combinations for multidrug resistant clinical isolates of OXA-48 carbapenemase producing Klebsiella pneumoniae.

Treatment of infections caused by OXA-48 carbapenemase producing multidrug-resistant isolates often necessitates combination therapy. In vitro effect of different antibiotic combinations against multidrug-resistant (MDR) Klebsiella pneumoniae isolates were evaluated in this study.Meropenem-tobramycin (MER+TOB), meropenem-ciprofloxacin (MER+CIP), colistin-meropenem (COL+MER), colistin-ciprofloxacin (COL+CIP) and colistin-tobramycin (COL+TOB) combinations were tested by time kill-assays.

Impact of Ceftazidime-Avibactam Treatment in the Emergence of Novel KPC Variants in the ST307-Klebsiella pneumoniae High-Risk Clone and Consequences for Their Routine Detection.

The emergence of Klebsiella pneumoniae isolates carrying novel variants conferring ceftazidime-avibactam (CAZ/AVI) resistance is being increasingly reported. We evaluated the accuracy of phenotypic methods commonly used in routine clinical laboratories in the detection of novel K. pneumoniae carbapenemase (KPC) enzymes.

Implementation of contact isolation strategy for the containment of extended-spectrum β-lactamase carriers in a University Hospital positively affects the epidemiology of carbapenemase-producing Enterobacterales.

Introduction: The lack of consensus of control measures to prevent extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) transmission in the hospital setting is of great concern. We describe the prevalence and species distribution of ESBL-E and carbapenemase producing Enterobacterales (CPE) in patients admitted in a tertiary Hospital during an active surveillance screening program for detecting ESBL-E carriers and reducing the ESBL-E transmission (R-GNOSIS Project).

Methods: From March-2014 to March-2016, 15,556 rectal swabs were collected from 8209 patients admitted in two medical (Gastroenterology, Pneumology) and two surgical (Neurosurgery, Urology) wards.

Evaluation of different phenotypic methods to detect methicillin resistance in Staphylococcus aureus isolates recovered from cystic fibrosis patients.

Methicillin-resistant Staphylococcus aureus (MRSA) detection in cystic fibrosis (CF) is challenging. We compared different phenotypic methods among 157 S. aureus from 136 CF-patients: cefoxitin (FOX) and oxacillin (OXA) broth-microdilution; MicroScan-WalkAway®; FOX and OXA disk-diffusion (DD), and PBP2a-latex agglutination.

Carbapenemase-producing infections in COVID-19 patients.

Background: Carbapenemase-producing (CPE) infections have been occasionally described in patients with coronavirus disease-19 (COVID-19). We assess the clinical features and outcome of these infections.

Methods: In this retrospective single-centre, case-control study, we included 54 patients with CPE infection: 30 case-patients (COVID-19) and 24 controls (non-COVID-19), collected between March and May 2020.

Evaluation of Rapid Polymyxin test in clinical isolates with various degrees of multidrug resistance.

Background: is of great concern among MDR bacteria and rapid and reliable antibiotic susceptibility testing methods are extremely necessary. Colistin is, in many cases, among the limited useful alternatives for these isolates. Unfortunately, only a few reliable methods are validated for testing susceptibility to colistin.

Anti-biofilm activity of murepavadin against cystic fibrosis Pseudomonas aeruginosa isolates.

Objectives: To determine the activity of murepavadin in comparison with tobramycin, colistin and aztreonam, against cystic fibrosis (CF) Pseudomonas aeruginosa isolates growing in biofilms. The biofilm-epidemiological cut-off (ECOFF) values that include intrinsic resistance mechanisms present in biofilms were estimated.

Methods: Fifty-three CF P.

Emergence of the New KPC-49 Variant Conferring an ESBL Phenotype with Resistance to Ceftazidime-Avibactam in the ST131-H30R1 High-Risk Clone.

We report the emergence of an isolate belonging to the sequence type (ST)131- high-risk clone with ceftazidime-avibactam resistance recovered from a patient with bacteremia in 2019. Antimicrobial susceptibility was determined and whole genome sequencing (Illumina-NovaSeq6000) and cloning experiments were performed to investigate its resistance phenotype. A KPC-3-producing isolate susceptible to ceftazidime-avibactam (MIC = 0.

Long-Term Impact of Suppressive Antibiotic Therapy on Intestinal Microbiota.

The aim was to describe the safety of indefinite administration of antibiotics, the so-called suppressive antibiotic therapy (SAT) and to provide insight into their impact on gut microbiota. 17 patients with SAT were recruited, providing a fecal sample. Bacterial composition was determined by 16S rDNA massive sequencing, and their viability was explored by PCR-DGGE with and without propidium monoazide.

Murepavadin antimicrobial activity against and resistance development in cystic fibrosis Pseudomonas aeruginosa isolates.

Background: Murepavadin, a novel peptidomimetic antibiotic, is being developed as an inhalation therapy for treatment of Pseudomonas aeruginosa respiratory infection in people with cystic fibrosis (CF). It blocks the activity of the LptD protein in P. aeruginosa causing outer membrane alterations.

Emergence and Persistence over Time of Carbapenemase-Producing Isolates in a Spanish University Hospital in Madrid, Spain (2005-2018).

Carbapenemase production is constantly increasing among different species. We analyzed the microbiological characteristics and population structure of all carbapenemase-producing spp. (CP-Ent) isolates recovered at the Ramón y Cajal Hospital between 2005 and 2018.

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

Objectives: 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.

Methods: 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.

Implementation of contact isolation strategy for the containment of extended-spectrum β-lactamase carriers in a University Hospital positively affects the epidemiology of carbapenemase-producing Enterobacterales.

Introduction: The lack of consensus of control measures to prevent extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) transmission in the hospital setting is of great concern. We describe the prevalence and species distribution of ESBL-E and carbapenemase producing Enterobacterales (CPE) in patients admitted in a tertiary Hospital during an active surveillance screening program for detecting ESBL-E carriers and reducing the ESBL-E transmission (R-GNOSIS Project).

Methods: From March-2014 to March-2016, 15,556 rectal swabs were collected from 8209 patients admitted in two medical (Gastroenterology, Pneumology) and two surgical (Neurosurgery, Urology) wards.

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

Carbapenemase-producing (CPE) have become an important public health concern. In our hospital, VIM enzymes were first detected in 2005, carbapenemase (KPC) enzymes in 2009, and OXA-48 enzymes in 2012. We assess the population biology of the first OXA-48-producing isolates recovered in our hospital (2012 to 2013) where infections by other carbapenemases had been endemic for several years.

Intestinal co-colonization with different carbapenemase-producing isolates is not a rare event in an OXA-48 endemic area.

Background: The current spread of carbapenemase-producing (CPE) is a great concern.

Methods: We recovered 198 CPE from 162 patients admitted in our Hospital (March 2014-March 2016) during the R-GNOSIS European Project. Microbiological features and plasmid characteristics of CPE recovered from patients co-colonized with multiple CPE were studied.

Hypermucoviscous : A challenge in community acquired infection.

In 1986, a new syndrome was described in Taiwan secondary to hypervirulent (hvKP), and its main feature was the ability to cause severe infection in young and immunocompetent hosts. Their virulence is explained by the efficient acquisition of iron and an increase in capsule production, which confer the characteristic hypermucoviscous phenotype. Most of these cases have been described in Asia and subsequently spread to America and Europe, where their prevalence is much lower.

Outbreak of NDM-1+CTX-M-15+DHA-1-producing Klebsiella pneumoniae high-risk clone in Spain owing to an undetectable colonised patient from Pakistan.

Here we describe an outbreak due to NDM-1+CTX-M-15+DHA-1-producing Klebsiella pneumoniae (NDM-1-Kp) in Spain related to a patient previously admitted to a healthcare centre in an endemic area (Pakistan). Nine colonised patients were detected in the Neurosurgery ward between September 2015 and February 2016 during the R-GNOSIS European Project. NDM-1-Kp isolates from clinical samples were also recovered in three of these patients.

Whole-genome sequencing reveals nosocomial Clostridioides difficile transmission and a previously unsuspected epidemic scenario.

To trace the routes and frequencies of transmission of Clostridioides difficile in a tertiary-care hospital in Madrid (Spain), we sequenced the genomes from all C. difficile isolates collected over 36 months (2014-2016) that were indistinguishable from any other isolate by PCR ribotyping. From a total of 589 C.

Recommendations of the Spanish Antibiogram Committee (COESANT) for selecting antimicrobial agents and concentrations for in vitro susceptibility studies using automated systems.

Automated antimicrobial susceptibility testing devices are widely implemented in clinical microbiology laboratories in Spain, mainly using EUCAST (European Committee on Antimicrobial Susceptibility Testing) breakpoints. In 2007, a group of experts published recommendations for including antimicrobial agents and selecting concentrations in these systems. Under the patronage of the Spanish Antibiogram Committee (Comité Español del Antibiograma, COESANT) and the Study Group on Mechanisms of Action and Resistance to Antimicrobial Agents (GEMARA) from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), and aligned with the Spanish National Plan against Antimicrobial Resistance (PRAN), a group of experts have updated this document.

Impact of De-escalation on Prognosis of Patients With Bacteremia due to Enterobacteriaceae: A Post Hoc Analysis From a Multicenter Prospective Cohort.

Background: More data are needed about the safety of antibiotic de-escalation in specific clinical situations as a strategy to reduce exposure to broad-spectrum antibiotics. The aims of this study were to investigate predictors of de-escalation and its impact on the outcome of patients with bloodstream infection due to Enterobacteriaceae (BSI-E).

Methods: A post hoc analysis was performed on a prospective, multicenter cohort of patients with BSI-E initially treated with ertapenem or antipseudomonal β-lactams.

Emergence and dissemination of colistin-resistant Klebsiella pneumoniae isolates expressing OXA-48 plus CTX-M-15 in patients not previously treated with colistin in a Spanish university hospital.

Dissemination of multidrug-resistant Klebsiella pneumoniae in the hospital environment represents a primary target of resistance containment and stewardship programs. At present, polymyxins, mostly in combination, exemplify a last-resort alternative. Colistin-resistant K.