Topical adjunctive treatment with flagellin augments pulmonary neutrophil responses and reduces bacterial dissemination in multidrug-resistant infection.

Objective: Antimicrobial resistance is an emerging problem and multi-drug resistant (MDR) () represents an enormous risk of failing therapy in hospital-acquired pneumonia. The current study aimed to determine the immunomodulatory effect of topical flagellin in addition to antibiotic treatment during respiratory infection evoked by hypervirulent antibiotic-susceptible and antibiotic-resistant in mice.

Methods: C57BL6 mice were inoculated intranasally with hypervirulent (K2:O1) which was either antibiotic-susceptible or multi-drug resistant.

Immunostimulatory Effect of Flagellin on MDR--Infected Human Airway Epithelial Cells.

Pneumonia caused by multi-drug-resistant (MDR-) poses a major public health threat, especially to immunocompromised or hospitalized patients. This study aimed to determine the immunostimulatory effect of the Toll-like receptor 5 ligand flagellin on primary human lung epithelial cells during infection with MDR-. Human bronchial epithelial (HBE) cells, grown on an air-liquid interface, were inoculated with MDR- on the apical side and treated during ongoing infection with antibiotics (meropenem) and/or flagellin on the basolateral and apical side, respectively; the antimicrobial and inflammatory effects of flagellin were determined in the presence or absence of meropenem.

Using Targeted Liquid Chromatography-Tandem Mass Spectrometry to Rapidly Detect β-Lactam, Aminoglycoside, and Fluoroquinolone Resistance Mechanisms in Blood Cultures Growing or .

New and rapid antimicrobial susceptibility/resistance testing methods are required for bacteria from positive blood cultures. In this study, a multiplex-targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated for the detection of β-lactam, aminoglycoside, and fluoroquinolone resistance mechanisms in blood cultures growing or complex. Selected targets were the β-lactamases SHV, TEM, OXA-1-like, CTX-M-1-like, CMY-2-like, chromosomal AmpC (cAmpC), OXA-48-like, NDM, VIM, and KPC; the aminoglycoside-modifying enzymes AAC(3)-Ia, AAC(3)-II, AAC(3)-IV, AAC(3)-VI, AAC(6')-Ib, ANT(2 )-I, and APH(3')-VI; the 16S-RMTases ArmA, RmtB, RmtC, and RmtF; the quinolone resistance mechanisms QnrA, QnrB, AAC(6')-Ib-cr; the wildtype quinolone resistance determining region of GyrA; and the porins OmpC and OmpF.

High Prevalence of ST502 Carrying an OXA-24 Carbapenemase gene in Carbapenem-Nonsusceptible Isolates in Romania.

can cause difficult-to-treat infections because it can acquire extensive antimicrobial resistance mechanisms. We aim to describe the antimicrobial resistance pattern and the genetic basis of carbapenem-nonsusceptible isolates in a University Hospital in Romania, a country where multidrug-resistant is widespread. We collected 104 consecutive meropenem-nonsusceptible isolates from 104 patients (36% female, mean age [SD] of 63 [16] years) between May 2015 and August 2017 from a large tertiary center in Romania.

Liquid Chromatography-Tandem Mass Spectrometry Analysis Demonstrates a Decrease in Porins and Increase in CMY-2 β-Lactamases in Exposed to Increasing Concentrations of Meropenem.

While Extended-Spectrum β-Lactamases (ESBL) and AmpC β-lactamases barely degrade carbapenem antibiotics, they are able to bind carbapenems and prevent them from interacting with penicillin-binding proteins, thereby inhibiting their activity. Further, it has been shown that can become resistant to carbapenems when high concentrations of ESBL and AmpC β-lactamases are present in the bacterial cell in combination with a decreased influx of antibiotics (due to a decrease in porins and outer-membrane permeability). In this study, a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed for the detection of the porins OmpC and OmpF, its chromosomal AmpC β-lactamase, and the plasmid-mediated CMY-2 β-lactamase.

Exploring antimicrobial resistance to beta-lactams, aminoglycosides and fluoroquinolones in E. coli and K. pneumoniae using proteogenomics.

Antimicrobial resistance is mostly studied by means of phenotypic growth inhibition determinations, in combination with PCR confirmations or further characterization by means of whole genome sequencing (WGS). However, the actual proteins that cause resistance such as enzymes and a lack of porins cannot be detected by these methods. Improvements in liquid chromatography (LC) and mass spectrometry (MS) enabled easier and more comprehensive proteome analysis.

Rapid and Accurate Detection of Aminoglycoside-Modifying Enzymes and 16S rRNA Methyltransferases by Targeted Liquid Chromatography-Tandem Mass Spectrometry.

New and rapid diagnostic methods are needed for the detection of antimicrobial resistance to aid in curbing drug-resistant infections. Targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a method that could serve this purpose, as it can detect specific peptides of antimicrobial resistance mechanisms with high accuracy. In the current study, we developed an accurate and rapid targeted LC-MS/MS assay based on parallel reaction monitoring for detection of the most prevalent aminoglycoside-modifying enzymes and 16S rRNA methyltransferases in Escherichia coli and Klebsiella pneumoniae that confer resistance to aminoglycosides.

The accuracy of four commercial broth microdilution tests in the determination of the minimum inhibitory concentration of colistin.

Colistin is considered as one of the last-resort antibiotics and reliable antimicrobial susceptibility testing is therefore crucial. The reference standard for AST according to EUCAST and CLSI is broth microdilution (BMD). However, BMD is labor intensive to perform.

Therapeutic Efficacy of Novel Antimicrobial Peptide AA139-Nanomedicines in a Multidrug-Resistant Klebsiella pneumoniae Pneumonia-Septicemia Model in Rats.

Antimicrobial peptides (AMPs) have seen limited clinical use as antimicrobial agents, largely due to issues relating to toxicity, short biological half-life, and lack of efficacy against Gram-negative bacteria. However, the development of novel AMP-nanomedicines, i.e.

Clinical impact of endemic NDM-producing Klebsiella pneumoniae in intensive care units of the national referral hospital in Jakarta, Indonesia.

Objective: A prospective observational study was performed to assess the epidemiology and clinical impact of carbapenem-non-susceptible Klebsiella pneumoniae (CNKP) in intensive care units (ICUs) of the national referral hospital in Jakarta, Indonesia.

Materials/methods: Adult patients consecutively hospitalized for > 48 h in two ICUs of the national referral hospital were included from April until October 2013 and from April until August 2014. K.

Successful High-Dosage Monotherapy of Tigecycline in a Multidrug-Resistant Pneumonia-Septicemia Model in Rats.

Recent scientific reports on the use of high dose tigecycline monotherapy as a "drug of last resort" warrant further research into the use of this regimen for the treatment of severe multidrug-resistant, Gram-negative bacterial infections. In the current study, the therapeutic efficacy of tigecycline monotherapy was investigated and compared to meropenem monotherapy in a newly developed rat model of fatal lobar pneumonia-septicemia. A producing extended-spectrum β-lactamase (ESBL) and an isogenic variant producing carbapenemase (KPC) were used in the study.

Whole-genome sequencing to explore nosocomial transmission and virulence in neonatal methicillin-susceptible Staphylococcus aureus bacteremia.

Background: Neonatal Staphylococcus aureus (S. aureus) bacteremia is an important cause of morbidity and mortality. In this study, we examined whether methicillin-susceptible S.

High-Risk International Clones of Carbapenem-Nonsusceptible Pseudomonas aeruginosa Endemic to Indonesian Intensive Care Units: Impact of a Multifaceted Infection Control Intervention Analyzed at the Genomic Level.

Infection control effectiveness evaluations require detailed epidemiological and microbiological data. We analyzed the genomic profiles of carbapenem-nonsusceptible (CNPA) strains collected from two intensive care units (ICUs) in the national referral hospital in Jakarta, Indonesia, where a multifaceted infection control intervention was applied. We used clinical data combined with whole-genome sequencing (WGS) of systematically collected CNPA to infer the transmission dynamics of CNPA strains and to characterize their resistome.

Cefpirome Treatment Results in Limited Selection of Stable Derepressed Mutants in the Intestinal Flora of Rats Treated for an Experimental Pulmonary Infection.

Fourth-generation cephalosporins have been developed to improve their potency, that is, low minimal inhibitory concentrations (MICs) and to prevent resistance selection of derepressed AmpC-producing mutants in comparison to third-generation cephalosporins as ceftazidime. We investigated the role of the administered cefpirome dose on the efficacy of treatment of a lung infection as well as in the selection of resistant isolates in the intestines of rats treated for a lung infection. Rats with lung infection received therapy with cefpirome doses of 0.

Epidemiology and characterisation of carbapenem-non-susceptible Pseudomonas aeruginosa in a large intensive care unit in Jakarta, Indonesia.

The aim of this study was to describe the epidemiology and clinical impact of carbapenem-non-susceptible Pseudomonas aeruginosa (CNPA) in intensive care units (ICUs) of the national referral hospital of Indonesia. Adult patients admitted to ICUs were prospectively included. Pseudomonas aeruginosa were from clinical cultures and systematic screening.

Antimicrobial activity of two novel antimicrobial peptides AA139 and SET-M33 against clinically and genotypically diverse Klebsiella pneumoniae isolates with differing antibiotic resistance profiles.

Colistin is an antimicrobial peptide (AMP) used as a drug of last resort, although plasmid-mediated colistin resistance (MCR) has been reported. AA139 and SET-M33 are novel AMPs currently in development for the treatment of multidrug-resistant (MDR) Gram-negative bacterial infections. As many AMPs have a similar mode of action to colistin, potentially leading to cross-resistance, the antimicrobial activity of AA139 and SET-M33 was investigated against a collection of 50 clinically and genotypically diverse Klebsiella pneumoniae isolates with differing antibiotic resistance profiles, including colistin-resistant strains.

Antibiotic-nanomedicines: facing the challenge of effective treatment of antibiotic-resistant respiratory tract infections.

Respiratory tract infections are one of the most frequent infections worldwide, with an increasing number being associated with (multiple) antibiotic-resistant pathogens. Improved treatment requires the development of new therapeutic strategies, including the possible development of antibiotic-nanomedicines. Antibiotic-nanomedicines comprise antibiotic molecules coupled to nanocarriers via surface adsorption, surface attachment, entrapment or conjugation and can be administered via aerosolization.

Spread of Carbapenem Resistance by Transposition and Conjugation Among .

The emergence of carbapenem-resistant represents a worldwide problem. To understand the carbapenem-resistance mechanisms and their spreading among strains, whole genome sequences were determined of two extensively drug-resistant strains that are endemic in Dutch hospitals. Strain Carb01 63 is of O-antigen serotype O12 and of sequence type ST111, whilst S04 90 is a serotype O11 strain of ST446.

PME and Other ESBL-Positive Multiresistant Pseudomonas aeruginosa Isolated from Hospitalized Patients in the Region of Kurdistan, Iraq.

Nosocomial infections occur worldwide and also in the Kurdistan region. Frequently patients colonized with multiresistant Pseudomonas aeruginosa isolates are encountered in many hospitals. As information is lacking with respect to the mechanisms of resistance responsible for the multiresistant character of the P.

Endemic carbapenem-nonsusceptible complex in intensive care units of the national referral hospital in Jakarta, Indonesia.

Background: Carbapenem-nonsusceptible complex have emerged worldwide, but the epidemiology in Indonesian hospitals has not been studied.

Methods: A prospective observational study was performed on the intensive care units (ICUs) of the national referral hospital in Jakarta-Indonesia, in 2013 and 2014. All consecutive adult patients admitted and hospitalized for >48 h in ICUs were included.

Investigations into the killing activity of an antimicrobial peptide active against extensively antibiotic-resistant K. pneumon iae and P. aeruginosa.

SET-M33 is a multimeric antimicrobial peptide active against Gram-negative bacteria in vitro and in vivo. Insights into its killing mechanism could elucidate correlations with selectivity. SET-M33 showed concentration-dependent bactericidal activity against colistin-susceptible and resistant isolates of P.

Environmental Spread of New Delhi Metallo-β-Lactamase-1-Producing Multidrug-Resistant Bacteria in Dhaka, Bangladesh.

Resistance to carbapenem antibiotics through the production of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes an emerging challenge in the treatment of bacterial infections. To monitor the possible source of the spread of these organisms in Dhaka, Bangladesh, we conducted a comparative analysis of wastewater samples from hospital-adjacent areas (HAR) and from community areas (COM), as well as public tap water samples, for the occurrence and characteristics of NDM-1-producing bacteria. Of 72 HAR samples tested, 51 (71%) samples were positive for NDM-1-producing bacteria, as evidenced by phenotypic tests and the presence of the gene, compared to 5 of 41 (12.