Many laboratory strains of Escherichia coli are resistant to methotrexate (MTX), a folate analogue that binds dihydrofolate reductase (DHFR). Mutations that inactivate either tolC or acrA confer MTX sensitivity. Further, overexpression of a fusion protein with DHFR activity reverses this sensitivity by titrating out intracellular MTX. These results suggest that MTX accumulates in cells where mu...

Drug exporters contribute to the intrinsic drug resistance in many organisms. Although there are at least 20 exporter genes in Escherichia coli, most of them apparently do not confer drug resistance in complex laboratory media except for the AcrAB, EmrE, and MdfA efflux systems. In this study, we comprehensively investigated the growth phase-dependent expression of drug exporter genes. The expr...

the present study aimed to evaluate the antibiotic resistance pattern of escherichia coli strains isolatedfrom animals to ascertain the levels of antibiotic resistance pervasiveness. a total of 28 e. coli strains wereisolated from faecal samples and the antibiotic resistance pattern of e. coli strains was determined by meansof disc diffusion assay. the resistance pattern determined for all stra...

Efflux pump inhibitors (EPIs) are attractive compounds to reverse multidrug-resistance in clinically relevant bacterial pathogens. In this study we tested the ability of the neuroleptic drug pimozide to inhibit the Escherichia coli AcrAB-TolC efflux pump, whose overproduction confers resistance to various antimicrobial agents. A real-time Nile red efflux assay in the AcrAB - overproducing strai...

background and objectives : salmonella is one of the leading causes of food-borne diseases. increasing occurrence of antimicrobial resistance, especially multidrug-resistance, in salmonella serovars is a major public health problem worldwide. this study was carried out to detect class i integrons and antibiotic resistance profiles in clinical isolates of salmonella serovars collected from seven...

conclusions despite the higher frequency of s. aureus nasal carriage in the interns, compared to the first year students, the difference did not reach statistical significance. therefore, attendance at medical centers cannot be considered a risk factor for increasing carriage. results out of the 200 nasal swabs obtained, the overall nasal carriage of s. aureus was 24.5% (49/200). the prevalence...

the occurrence of antibiotic-resistant pathogenic bacteria is becoming a serious problem. the rise of multiresistance strains has forced the pharmaceutical industry to come up with new generation of more effective and potent antibiotics, therefore creating development of antivirulence compounds. due to extensive usage of cell-to-cell bacterial communication (qs) systems to monitor the productio...

introduction urinary tract infection (uti) is one of the most common infections in childhood. appropriate treatment of uti requires to knowledge about antibiotic resistance patterns of common uropathogens. the aim of this study was to determine demographic, symptoms, signs and antibiotic resistance pattern in admitted infants with clinically diagnosis of uti in 17 shahrivar hospital of rasht ma...

background and objective: gastroenteritis is one of the most important diseases in the world. this disease is more critical among children, people with immune deficiency and the sufferers from mal-nutrition. shigella spp. as the most important cause of dysentery, causes much mortality around the world. increasing antibiotic resistance is one of the major health problems. this research aimed to ...

background and aims: acinetobacter baumannii is regarded as an important nosocomial pathogen around the world, especially in the intensive care unit that today seems to be resistant to the most antibiotics. therefore, this study aimed to trace classes 1, 2, and 3 integrin in the isolates resistant to acinetobacter baumannii. materials and methods: in this descriptive study, acinetobacter bauman...