Search results for "drug resistance"
showing 10 items of 953 documents
Cytotoxicity of cucurbitacin E from Citrullus colocynthis against multidrug-resistant cancer cells
2019
Abstract Background Cucurbitacin E (CuE) is an oxygenated tetracyclic triterpenoid isolated from the fruits of Citrullus colocynthis (L.) Schrad. Purpose This study outlines CuE's cytotoxic activity against drug-resistant tumor cell lines. Three members of ABC transporters superfamily, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and ABCB5 were investigated, whose overexpression in tumors is tightly linked to multidrug resistance. Further factors of drug resistance studied were the tumor suppressor TP53 and the epidermal growth factor receptor (EGFR). Methods Cytotoxicity assays (resazurin assays) were used to investigate the activity of Citrullus colocynthis and CuE towar…
Liver and gastrointestinal cancers
2020
Abstract One important limitation in the treatment of liver and gastrointestinal cancers is their poor response to available chemotherapy, which is due in part to efficient mechanisms of defense against antitumor drugs. An important role in chemoresistance is played by ATP-binding cassette (ABC) proteins, normally involved in barrier/secretory functions of the digestive apparatus. ABC pumps, often up-regulated in cancers derived from these organs, actively export antitumor agents from cancer cells, thereby reducing the pharmacological effect of these drugs. Among the ABC proteins with the highest impact on the multidrug resistance (MDR) phenotype of many cancer types is MDR1 or P-glycoprote…
Co-colonization with carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii in intensive care unit patients
2013
Objectives: This investigation was conducted to study co-colonization by carbapenem-resistant Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) and Acinetobacter baumannii (CRAB) in intensive care unit (ICU) patients in Palermo, Sicily, a geographic area where both organisms are endemic in the healthcare setting. Risk factors at admission and during ICU stay and outcomes were also evaluated. Methods: All patients colonized by KPC-Kp, or CRAB, or both in 2 ICUs of a large general hospital during the period October 2011 – March 2012 were enrolled. Demographics and clinical data were collected. Resistance determinants and clonality of the 2 organisms were characterized by mo…
New insights regarding Acinetobacter genomic island-related elements
2020
The objective of this study was to mobilize the Acinetobacter genomic island 1-A (AGI1-A) from Enterobacter hormaechei EclCSP2185 (E. cloacae complex) and to search for the distribution and structure of AGI1-related elements in the NCBI database. AGI1-A was transferred to Escherichia coli. Analysis of the attachment (att) sites could locate the possible recombination crossover in the att sequences at position 10-11 (GG) in the last 18 bp of trmE. In silico detection of AGI backbones in the wgs database identified AGI variants in Salmonella enterica (83 strains), Vibrio cholerae (33), E. hormaechei (12), Acinetobacter baumannii (2), most belonging to prevalent clones (ST40, ST69, ST114 and S…
Multidrug-resistant Gram-negative post-neurosurgical meningitis and the role of intraventricular colistin: a case series
2021
: The aim of this study was to report the clinical experience of intraventricular colistin for the treatment of multi-resistant Gram-negative post-surgical meningitis in a tertiary hospital. Post-neurosurgical meningitis (PNM) is one of the life-threatening complications of neurosurgical procedures, and is frequently sustained by Acinetobacter baumannii and Klebsiella pneumoniae. Here we describe our experience of five cases of PNM caused by gram-negative multi-drug resistant (MDR) bacteria, treated with intraventricular (IVT) colistin, admitted to the Neurosurgery Unit of A.R.N.A.S. Civico of Palermo, Italy, from January 2016 to June 2020. In four patients the cerebrospinal fluid (CSF) cul…
Molecular epidemiology of Acinetobacter baumannii in Iran: endemic and epidemic spread of multiresistant isolates
2014
Objectives We examined the molecular epidemiology of Acinetobacter baumannii clinical isolates from two cities (Tehran and Tabriz) of Iran. Methods DiversiLab repetitive extragenic palindromic PCR (rep-PCR), multilocus sequence typing and sequence group multiplex PCR were performed. The presence of resistance mechanisms including metallo-β-lactamases, extended-spectrum β-lactamases, OXA carbapenemases, aminoglycoside-modifying enzymes and RNA methylases was also investigated. Results DiversiLab rep-PCR identified 11 clusters and 11 singleton isolates. Twelve sequence types (STs), including six novel types, were identified. Sequence groups (SGs) 1-3 as well as five additional banding pattern…
Drug resistance patterns of bacteria isolated from patients with nosocomial pneumonia at Tehran hospitals during 2009-2011
2013
Introduction: Nosocomial pneumonia remains an important cause of mortality and morbidity worldwide. Surveillance programs play an important role in the identification of common etiologic agents and local patterns of antimicrobial resistance. Methodology: In this study we determined the frequency and antimicrobial susceptibility of pathogens isolated from patients with nosocomial pneumonia during 2009 to 2011. Results: A total of 642 bacteria were isolated from 516 suspected samples. Acinetobacter baumannii (21.1%, n = 136), was the commonest isolated pathogen followed by Pseudomonas aeruginosa (17.4%, n = 112) , Staphylococcus aureus (15.8%, n = 102) and enterococci (8.4% n = 54). The most …
High susceptibility of MDR and XDR Gram-negative pathogens to biphenyl-diacetylene-based difluoromethyl-allo-threonyl-hydroxamate LpxC inhibitors
2016
International audience; Inhibitors of uridine diphosphate-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC, which catalyses the first, irreversible step in lipid A biosynthesis) are a promising new class of antibiotics against Gram-negative bacteria. The objectives of the present study were to: (i) compare the antibiotic activities of three LpxC inhibitors (LPC-058, LPC-011 and LPC-087) and the reference inhibitor CHIR-090 against Gram-negative bacilli (including MDR and XDR isolates); and (ii) investigate the effect of combining these inhibitors with conventional antibiotics.MethodsMICs were determined for 369 clinical isolates (234 Enterobacteriaceae and 135 non-fermentati…
Genetic variation and urine cadmium levels: ABCC1 effects in the Strong Heart Family Study
2021
Abstract Genetic effects are suspected to influence cadmium internal dose. Our objective was to assess genetic determinants of urine cadmium in American Indian adults participating in the Strong Heart Family Study (SHFS). Urine cadmium levels and genotyped short tandem repeat (STR) markers were available on 1936 SHFS participants. We investigated heritability, including gene-by-sex and smoking interactions, and STR-based quantitative trait locus (QTL) linkage, using a variance-component decomposition approach, which incorporates the genetic information contained in the pedigrees. We also used available single nucleotide polymorphisms (SNPs) from Illumina’s Metabochip and custom panel to ass…
Bendamustine with or without rituximab in the treatment of relapsed chronic lymphocytic leukaemia: an Italian retrospective study.
2011
To retrospectively assess the efficacy of bendamustine alone and with rituximab (R-B), 109 patients with relapsed chronic lymphocytic leukaemia (CLL) were enrolled in 24 Italian centres. The median age was 66 years (range 39-85). Forty-three percent of patients had relapsed and 57% were resistant (median previous therapies = 3; range 1-8). Twenty-two patients received bendamustine alone and 87 patients received R-B (median B dosage: 100 mg/m(2) per day, range 90-130 mg/m(2) per day). The overall response rate was 69·6% (complete response 28·6%; partial response 41%), and was significantly higher in patients treated with R-B (P = 0·014) and in those responsive to the previous treatment (P=0·…