Project description:The present study examines changes in global gene expression patterns and in virulence factor-associated genes in an extended spectrum beta-lactamase (ESBL)-producing UPEC (ESBL019) during the morphologic transitions induced by an ineffective antibiotic and in the presence of human primary bladder epithelial cells. The morphological shifts induced by ineffective antibiotics are associated with significant transcriptional virulence alterations in ESBL-producing UPEC, which may affect survival and persistence in the urinary tract.
Project description:Treatment of urinary tract infections is today a challenge due to the increasing prevalence of multidrug-resistant ESBL-producing uropathogenic Escherichia coli (UPEC). There is an urgent need for new treatment strategies for multidrug-resistant UPEC and preferably with targets that have low potential for development of resistance. Carbon monoxide-releasing molecules (CORMs) are novel and potent antibacterial agents. The present study examines the transcriptomic targets of CORM-2 in a multidrug-resistant ESBL-producing UPEC isolate (ESBL7) in response to a single exposure to CORM-2 and after repeated exposure to CORM-2. The bacterial viability and minimal inhibitory concentration (MIC) were also examined after repeated exposure to CORM-2. Microarray analysis revealed that a wide range of processes were affected by CORM-2, including a general trend of down-regulation in energy metabolism and biosynthesis pathways and up-regulation of the SOS response and DNA repair. Several genes involved in virulence (ibpB), antibiotic resistance (marAB, mdtABC) and biofilm formation (bhsA, yfgF) were up-regulated, while some genes involved in virulence (kpsC, fepCEG, entABE), antibiotic resistance (evgA) and biofilm formation (artIP) were down-regulated. Repeated exposure to CORM-2 did not alter the gene expression patterns, the growth inhibitory response to CORM-2 or the MIC values for CORM-2, cefotaxime, ciprofloxacin and trimethoprim.
Project description:The global surge in multi-drug resistant bacteria, including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has led to a growing need for new antibacterial compounds. Despite being promising, the potential of fish-derived antimicrobial peptides (AMPs) in combating ESBL-E. coli is largely unexplored. In this study, native peptides were extracted from the skin mucus of farmed African Catfish, Clarias gariepinus, using a combination of 10 % acetic acid solvent hydrolysis, 5 kDa ultrafiltration, and C18 hydrophobic interactions. Peptides were then sequenced using Orbitrap Fusion Lumos Tribrid Mass Spectrometry. The identified peptides were screened for potential antibacterial activity using Random Forest and AdaBoost machine learning algorithms. The most promising peptide was then chemically synthesized and evaluated in vitro for safety on Rabbit red blood cells and activity against ESBL-E. coli (ATCC 35218) utilizing the spot-on-lawn and broth dilution methods. Eight short peptides were identified with 13 - 22 amino acid residues and molecular weight range of 968.42 to 2434.11 Da. Peptide, FACAP-II was non-hemolytic to rabbit erythrocytes (p>0.05), with Zone of Inhibition (ZOI) of 22.7 mm and Minimum Inhibitory concentration (MIC) of 91.3 μg/mL. The peptide is thus a candidate antibacterial compound with enormous potential applications in the pharmaceutical industry. However, further studies are still required to establish the upscale production strategy and optimize its activity and safety in vivo.
Project description:To characterize the differentially expressed genes between pathogenic avian E. coli and human E. coli ATCC 25922, Abstract Escherichia coli (E. coli) is a harmless common bacterium of poultry intestine, but with a wide range of genomic flexibility, is also causative agent of many poultry diseases collectively called colibacillosis that is blamed for high economic loss in poultry sector worldwide. Numerous studies have been conducted to check the prevalence of pathogenic E. coli in poultry and poultry products, however limited data are available regarding their resistance and virulence associated genes expression profile. This study examined the pathogenomic content of poultry E. coli by antibiotic susceptibility, biofilm formation and adhesion, invasion and intracellular survivability assays in Caco-2 and Raw 264.7 cell lines along with the determination of median lethal dose in two-day old chickens. A clinical pathogenic multidrug resistant (MDR) isolate, E. coli 381, isolated from broilers was found to be highly virulent in cell culture and in chicken model. Transcriptome analysis has been skewed towards bacterial pathogens because of the prioritization of poultry diseases. Comparative gene expression profile of MDR E. coli 381 and the reference human strain E. coli ATCC 25922 was done using Illumina HiSeq2500 transcriptome and results were verified by RT-qPCR analyses. A number of resistant encoding genes including multidrug transporters, multidrug resistance proteins, porins and autotransporters were identified. We also noticed overexpression of very important virulent genes (fimA, fimC, fimH and fimI) encoding the type-1 fimbrial proteins, curli fimbriae genes , invasin genes, toxin-encoding genes and biofilm forming regulatory genes . In addition, many types of stress and metal homeostasis controlling genes were among up-regulated genes in E. coli 381 as compared to reference strain. GO and KEGG pathway analysis results revealed that genes controlling secondary metabolism, drug transport, adhesion and invasion proteins, and mobile genetic elements were over-expressed in E. coli 381. Several genes involved in cellular and metabolic processes such as carbohydrate metabolism were responsible for stress tolerance. Seminal description of the transcriptomic results and other unique features of E. coli 381 confirmed that it is highly virulent and MDR strain of poultry origin. This comparative study provides new avenues for further work on molecular mechanisms to prevent resistance development in bacteria and to ensure public health.