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. Overall design: 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 (ceftibuten) in the presence of human primary bladder epithelial cells was evaluated by microarray after 4 hours. Four different morphologies were studied; Coliform, Transition (from Coli into Filamented), Filamented and Reverted (reverted back from a Filamented shape into a coli shape). Four independent experiments were included in each group.
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. Overall design: ESBL7 from the original isolate, or isolates pre-exposed 20 times to CORM-2 (250 µM) or vehicle (2.5% DMSO) for 4 hours at 37 °C, were used to inoculate MS-medium followed by exposure to CORM-2 (250 µM) or vehicle for 30 min at 37 °C. Microarray were performed on first exposure to sub-inhibitory levels of CORM-2 (250 µM), first exposure to vehicle (2.5% DMSO), pre-exposed 20 times to CORM-2 respectively pre-exposed 20 times to vehicle. Four independent experiments were included in each group.