In Vitro Synergistic Activity of Rifampicin Combined with Minimal Effective Antibiotic Concentration (MEAC) of Polymyxin B Against Extensively Drug-Resistant, Carbapenem-, and Polymyxin B-Resistant Klebsiella pneumoniae Clinical Isolates.

We investigated the in vitro antibacterial activity of the combination rifampicin (RIF) + polymyxin B (PB) against extensively drug-resistant (XDR) Klebsiella pneumoniae isolates. We evaluated clinical isolates co-resistant to PB (non-mcr carriers; eptB, mgrB, pmr operon, and ramA mutations) and to carbapenems (KPC, CTX-M, and SHV producers; including KPC + NDM co-producer), belonging to sequence types (ST) ST16, ST11, ST258, ST340, and ST437. We used the standard broth microdilution method to determine RIF and PB minimum inhibitory concentration (MIC) and the checkerboard assay to evaluate the fractional inhibitory concentration index (FICI) of RIF + PB as well as to investigate the lowest concentrations of RIF and PB that combined (RIF + PB) had antibacterial activity.

Hospital wastewater as source of human pathogenic bacteria: A phenotypic and genomic analysis of international high-risk clone VIM-2-producing Pseudomonas aeruginosa ST235/O11.

Pseudomonas aeruginosa belong to the special pathogen group capable of causing serious infections, with high mortality rates. The aim of this study was to describe the antibiotic resistance and genomic characteristics of Pseudomonas aeruginosa belonging to international high-risk clone ST235 (GPAE0131 isolate), obtained from hospital wastewater. P.

Multidrug-resistant Enterobacter spp. in wastewater and surface water: Molecular characterization of β-lactam resistance and metal tolerance genes.

Among the ESKAPE group pathogens, Enterobacter spp. is an opportunistic Gram-negative bacillus, widely dispersed in the environment, that causes infections. In the present study, samples of hospital wastewater, raw and treated urban wastewater, as well as surface receiving water, were collected to assess the occurrence of multidrug-resistant (MDR) Enterobacter spp.

The rise of multidrug resistant Salmonella isolates in healthy chickens in Brazil by successful establishment of plasmid IncHI2A carrying several antibiotic resistance genes.

Salmonella spp. is an important global issue in food-producing animals. The present study evaluated antimicrobial resistance and virulence profiles in Salmonella spp.

A set of antibiotic-resistance mechanisms and virulence factors in GES-16-producing Klebsiella quasipneumoniae subsp. similipneumoniae from hospital wastewater revealed by whole-genome sequencing.

Klebsiella quasipneumoniae subsp. similipneumoniae has emerged as a human pathogen and sporadic isolates from non-clinical sources were reported. Here, we described the phenotypic- and genomic-characteristics of a multidrug-resistant (MDR) and potentially hypervirulent (MDR-hv) Klebsiella quasipneumoniae subsp.

CD14 signaling mediates lung immunopathology and mice mortality induced by Achromobacter xylosoxidans.

Objective And Design: Our research aimed to investigate the role of CD14 in pulmonary infection by Achromobacter xylosoxidans in an experimental murine model.

Methods: C57Bl/6 or CD14-deficient mice were infected intratracheally with non-lethal inoculum of A. xylosoxidans.

Different virulence genetic context of multidrug-resistant CTX-M- and KPC-producing Klebsiella pneumoniae isolated from cerebrospinal fluid.

Information regarding resistance and virulence traits of meningitis-causing enterobacteria in hospital environment remains scarce. The aim of this study was to characterize virulence and acquired resistance genes of carbapenem-resistant and/or 3rd to 4th generation cephalosporin-resistant Klebsiella pneumoniae isolated from the cerebrospinal fluid of inpatients. Antimicrobial susceptibility testing was performed by disk diffusion.

The plasmidome of multidrug-resistant emergent Salmonella serovars isolated from poultry.

The rapid emergence of resistant bacteria is occurring worldwide. The understanding of the dissemination of antimicrobial resistance using high-throughput sequencing and bioinformatics approaches is providing valuable insights into the genetic basis of the horizontal gene transfer and the emergence of the antibiotic resistance threat. This ultimately can offer vital clues to the development of coordinated efforts to implement new policies to continue fighting against bacterial infections.

Extensively drug-resistant IMP-16-producing Pseudomonas monteilii isolated from cerebrospinal fluid.

IMP-1-producing Pseudomonas aeruginosa was first reported in Japan and since then, bacteria with this metallo-β-lactamase have been detected worldwide. Pseudomonas monteilii (part of P. putida group) were considered an environmental pathogen with low virulence potential; however, multidrug-resistant and carbapenem-resistant P.

High occurrence of heavy metal tolerance genes in bacteria isolated from wastewater: A new concern?

Some heavy metals have antimicrobial activity and are considered as potential alternatives to traditional antibiotic therapy. However, heavy metal tolerance genes (HMTG) have been already detected and coding different tolerance mechanisms. Considering that certain metals are promising for antimicrobial therapy, evaluation of HMTG dissemination in bacteria from sewage is essential to understand the evolution of these bacteria and to predict antimicrobial use and control.

Gram-negative bacteria carrying β-lactamase encoding genes in hospital and urban wastewater in Brazil.

Multidrug resistance mediated by β-lactamase in Gram-negative bacilli is a serious public health problem. Sewers are considered reservoirs of multiresistant bacteria due to presence of antibiotics that select them and favor their dissemination. The present study evaluated the antibiotic resistance profile and β-lactamases production in Gram-negative bacilli isolates from hospital sewage and urban wastewater treatment plants (UWWTP) in Brazil.

Antibiotic resistance and heavy metal tolerance plasmids: the antimicrobial bulletproof properties of isolated from poultry.

We describe the mobilome of 40A isolated from poultry, consisting of four different plasmids, p46_40A (IncX1, 45,869 bp), p80_40A (non-typable, 79,635 bp), p150_40A (IncI1-ST1, 148,340 bp) and p280_40A (IncHI2A-ST2, 279,537 bp). The mobilome-40A carries a blend of several different resistance and virulence genes, heavy metal tolerance operons and conjugation system. This mobilome 40A is a perfect tool to preserve and disseminate antimicrobial resistance and makes the bacterial isolate incredibly adapted to survive under constant antimicrobial pressure.

A Phage-Like Plasmid Carrying Gene in Carbapenem-Resistant .

Lateral gene transfer plays a central role in the dissemination of carbapenem resistance in bacterial pathogens associated with nosocomial infections, mainly and . Despite their clinical significance, there is little information regarding the mobile genetic elements and mechanism of acquisition and propagation of lateral genes in , and they remain largely unknown. The present study characterized the genetic context of in carbapenem-resistant strain BH9.

Evaluation of heavy metal tolerance genes in plasmids harbored in multidrug-resistant Salmonella enterica and Escherichia coli isolated from poultry in Brazil.

The emergence and spread of bacteria tolerant to heavy metal ions used in disinfectants have become a new threat to antimicrobial therapies. In this study, metal tolerance genes were analyzed in multidrug-resistant (MDR) Enterobacteriaceae isolated from chickens in Brazil. Different tolerance genes were found disseminated among the MDR isolates.

SPM-1-producing Pseudomonas aeruginosa ST277 carries a chromosomal pack of acquired resistance genes: An example of high-risk clone associated with 'intrinsic resistome'.

Objectives: The purpose of this study was to investigate the resistome of an SPM-1-producing Pseudomonas aeruginosa ST277 isolate (HC84) from Brazil.

Methods: Whole-genome sequencing of P. aeruginosa HC84 was performed using an Ion Protonâ„¢ System.

Adaptation of Pseudomonas aeruginosa to the chronic phenotype by mutations in the algTmucABD operon in isolates from Brazilian cystic fibrosis patients.

Chronic lung infection by Pseudomonas aeruginosa is the leading cause of morbidity and mortality in cystic fibrosis (CF) patients. This is associated with the conversion of the non-mucoid to the mucoid phenotype. However, there is little information about the occurrence of alginate-producing P.

Virulence potential of commensal multidrug resistant Escherichia coli isolated from poultry in Brazil.

There is an increasing number of reports worldwide about multidrug resistance (MDR) with potential of ExPEC in commensal E. coli. The present study evaluated the potential ExPEC in selected 44 MDR E.

Draft genome sequence of a KPC-2-producing Klebsiella pneumoniae ST340 carrying bla and bla genes: a rich genome of mobile genetic elements and genes encoding antibiotic resistance.

Objectives: Klebsiella pneumoniae is considered an opportunistic pathogen and an important agent of nosocomial and community infections. It presents the ability to capture and harbour several antimicrobial resistance genes and, in this context, the extensive use of carbapenems to treat serious infections has been responsible for the selection of several resistance genes. This study reports the draft genome sequence of a KPC-2-producing K.

Virulence genes, capsular and plasmid types of multidrug-resistant CTX-M(-2, -8, -15) and KPC-2-producing Klebsiella pneumoniae isolates from four major hospitals in Brazil.

We performed a single-month snapshot study of the population diversity of multidrug resistant (MDR) Klebsiella pneumoniae isolates producing carbapenemases and/or extended-spectrum β-lactamases from four major hospitals in Brazil. Isolates produced diverse ESBL (CTX-M-2, -8, -15, SHV-2), KPC-2 or both (CTX-M-2 and KPC-2), linked to specific genetic backgrounds and plasmids from a few families (IncR, IncFIIk, IncL/M) that were shared among clonal lineages within and between hospitals. A high clonal diversity was identified, among isolates from the same ST (ST11, ST15, ST101 or ST340).

Diversity of plasmids harboring bla in multidrug-resistant Escherichia coli isolated from poultry in Brazil.

Multidrug-resistance (MDR) has been increasingly reported in Gram-negative bacteria from the intestinal microbiota, environment and food-producing animals. Resistance plasmids able to harbor different transposable elements are capable to mobilize antimicrobial resistance genes and transfer to other bacterial hosts. Plasmids carrying bla are frequently associated with MDR.

Transfer of KPC-2 carbapenemase from Klebsiella pneumoniae to Enterobacter cloacae in a patient receiving meropenem therapy.

The horizontal transfer of a plasmid bearing the bla gene from K. pneumoniae to E. cloacae infecting the respiratory tract of a patient during meropenem therapy was elucidated.