Antimicrobial resistance of Escherichia coli isolates from outpatient urinary tract infections in women in six European countries including Russia

Objectives In the Northern Dimension Antibiotic Resistance Study (NoDARS), Finland, Germany, Latvia, Poland, Russia and Sweden collected urine samples from outpatient women (aged 18–65 years) with symptoms of uncomplicated urinary tract infection (UTI) to investigate the levels of antimicrobial resistance (AMR) among Escherichia coli isolates. Methods A total of 775 E. coli isolates from 1280 clinical urine samples were collected from October 2015 to January 2017. Antimicrobial susceptibility testing was performed and the results were interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Results Overall AMR rates to the commonly used antibiotics nitrofurantoin, fosfomycin and mecillinam (except for Germany that was missing a result for mecillinam) were 1.2%, 1.3% and 4.1%, respectively. The highest overall resistance rates were determined for ampicillin (39.6%), trimethoprim (23.8%), trimethoprim/sulfamethoxazole (22.4%), amoxicillin/clavulanic acid (16.7%) and ciprofloxacin (15.1%), varying significantly between countries. The rate of extended-spectrum β-lactamase (ESBL) production was 8.7%. None of the isolates showed resistance to meropenem. Conclusions In most cases, low AMR rates were detected against the first-line antibiotics recommended in national UTI treatment guidelines, giving support to their future use. These results also support the European Association of Urology guidelines stating that nitrofurantoin, fosfomycin and mecillinam are viable treatment options for uncomplicated UTI.Peer Reviewe

Antibiotic resistance in Gram-negative bacilli : With focus on cephalosporin resistance mechanisms in Escherichia coli and Klebsiella pneumoniae

Objectives. The objectives of this thesis were to study mechanisms conferring cefuroxime resistance in clinical non-ESBL (extended-spectrum beta-lactamase) producing isolates of Escherichia coli and Klebsiella pneumoniae, as well as the presence of co-resistance to other antibiotics in the K. pneumoniae isolates. Further, the objectives were to study findings of and resistance patterns of Gram-negative bacilli isolated from patients seeking medical advice in Stockholm after the tsunami catastrophe. Materials and methods. In paper I 30 clinical non-ESBL blood culture isolates of E. coli with various degrees of cefuroxime susceptibility were examined. Cefuroxime susceptibility was determined in the presence of the efflux pump inhibitor phenylalanine arginine beta-naphthylamide (PAbetaN). Organic solvent tolerance (OST) was determined, as a phenotypic method for detecting efflux. In paper II 14 clinical non-ESBL isolates of E. coli with various degrees of cefuroxime susceptibility were examined. Transcription levels of acrA (encoding AcrA, part of the AcrAB-TolC efflux pump) and ompF (encoding the porin OmpF) were determined with quantitative RTPCR. AmpC activity was determined with spectrophotometry. In paper III an epidemiological survey was made of findings of and resistance patterns of Gramnegative bacilli from patients seeking medical advice in Stockholm after the tsunami catastrophe. In paper IV ten blood culture isolates of K. pneumoniae, all cefuroximeresistant, but cefotaxime susceptible and a multiply antibiotic resistant (MAR) laboratory strain (selected by chloramphenicol) were examined. Transcription levels of acrA, ompK35 (the homologue of ompF), and of the regulatory genes ramA, marA and soxS were determined with quantitative RT-PCR. Antibiotic susceptibility was also determined in the presence of PAbetaN. Results. In paper I was shown that the organic solvent tolerant isolates had significantly decreased susceptibility to cefuroxime compared to the non-tolerant isolates. Further, the susceptibility to cefuroxime was increased by PAbetaN for thecyclohexane tolerant isolates. In paper II, increased acrA transcription was seen in seven of the eleven cefuroxime resistant isolates. Very low ompF transcription levels were seen in three and increased AmpC activity in two of the cefuroxime resistant isolates. Paper III showed that findings of various Gram-negative bacilli were common in secretion cultures from the tsunami victims and that resistant isolates of E. coli, K. pneumoniae, Proteus mirabilis and Acinetobacter spp. were more common in cultures from tsunami victims compared to the Swedish reference material, as was not the case for Pseudomonas aeruginosa. In paper IV all examined isolates and the laboratory strain showed similar antibiograms with decreased susceptibility to cefuroxime, chloramphenicol, nalidixic acid and tigecycline. All strains also had increased acrA transcription and decreased ompK35 transcription. The laboratory strain and all the clinical isolates except one displayed increased ramA transcription. PAbetaN increased susceptibility to chloramphenicol, nalidixic acid and tigecycline, but not to cefuroxime. Conclusions. In clinical non-ESBL cefuroxime resistant isolates of E. coli several resistance mechanisms (efflux of the AcrAB-TolC complex, lack of OmpF and increased AmpC activity) seem to contribute to cefuroxime resistance. In K. pneumoniae a multidrug resistant (MDR) phenotype was observed in all the examined isolates, with decreased susceptibility to cefuroxime, chloramphenicol, nalidixic acid and tigecycline. Further, the same resistance mechanisms were detected in almost all clinical isolates. The findings of various Gram-negative bacteria from tsunami victims affect which empirical antibiotic treatment should be given when these kinds of traumatic infections are treated

Antibiotic resistance of Escherichia coli from outpatient urinary tract infection in women in six European countries including Russia

In the Northern Dimension Antibiotic Resistance Study Finland, Germany, Latvia, Poland, Russia and Sweden investigated the resistance levels of Escherichia coli (E. coli) isolated from urine of outpatient women (18-65 years) that had symptoms of uncomplicated UTI by collecting samples in each respective nation.\nOverall antibiotic resistance (ABR) rates to certain commonly used antibiotics, such as nitrofurantoin, fosfomycin and mecillinam were 1.2%, 1.3% and 4.1% (except for Germany that was missing result for mecillinam). Highest overall resistance rates were determined for ampicillin - 39.6%, trimethoprim -23.8%, trimethoprim/sulfamethoxazole -22.4%, amoxillin/clavulanic acid - 16.7% and ciprofloxacin - 15.1%, varying significantly among the countries. ESBL-production level was 8.7%. None of the isolates showed resistance to meropenem.\nIn total 775 E. coli isolates from 1278 clinical urinary samples were collected from October 2015-January 2017. Susceptibility testing was performed and results were interpreted according to the EUCAST criteria.\nIn most cases, low ABR rates were detected against the first line antibiotics recommended in national UTI treatment guidelines which give support to their future use. Our results also support the European Association of Urology guidelines stating that nitrofurantoin, fosfomycin and mecillinam are viable treatment options for uncomplicated UTI.\nOBJECTIVES\nRESULTS\nMETHODS\nCONCLUSION