Recommendations for the empirical treatment of complicated urinary tract infections using surveillance data on antimicrobial resistance in the Netherlands

Nitrofuran Derivatives Cross-Resistance Evidence-Uropathogenic Escherichia coli Nitrofurantoin and Furazidin In Vitro Susceptibility Testing

The treatment of urinary tract infections is usually empirical. For example, nitrofuran derivatives, mainly nitrofurantoin (but also furazidin), are used in Eastern Europe. A significant problem is the assessment of the usefulness of furazidin, as there are no standards for susceptibility testing. Additionally, a high percentage of strains resistant to nitrofurantoin should prompt caution when choosing furazidin in therapy. This study aimed to answer the question of whether it is possible to use nitrofurantoin susceptibility for furazidin drug susceptibility analyses and if there is any cross-resistance in the nitrofuran derivatives group. One hundred E. coli clinical isolates, obtained from the Central Teaching Hospital of the Medical University of Lodz, were cultured from positive urine samples. For susceptibility testing, microdilution and disk diffusion methods, following EUCAST guidelines, were used. The results showed that the MICs of furazidin were equal to or lower than those of nitrofurantoin in 89% of the tested strains. The MIC50/90 values for furazidin were two times lower than those for nitrofurantoin. Positive correlations were found between MICs and growth inhibition zones for both antibiotics. Based on the obtained data and previous studies, it was assumed that the transfer of susceptibility testing results from nitrofurantoin to furazidin is acceptable due to cross-resistance in nitrofuran derivatives.

Antimicrobial resistance in urinary pathogens and culture-independent detection of trimethoprim resistance in urine from patients with urinary tract infection

Background

Although urinary tract infections (UTIs) are extremely common, isolation of causative uropathogens is not always routinely performed, with antibiotics frequently prescribed empirically. This study determined the susceptibility of urinary isolates from two Health and Social Care Trusts (HSCTs) in Northern Ireland to a range of antibiotics commonly used in the treatment of UTIs. Furthermore, we determined if detection of trimethoprim resistance genes (dfrA) could be used as a potential biomarker for rapid detection of phenotypic trimethoprim resistance in urinary pathogens and from urine without culture.

Methods

Susceptibility of E. coli and Klebsiella spp. isolates (n = 124) to trimethoprim, amoxicillin, ceftazidime, ciprofloxacin, co-amoxiclav and nitrofurantoin in addition to susceptibility of Proteus mirabilis (n = 61) and Staphylococcus saprophyticus (n = 17) to trimethoprim was determined by ETEST® and interpreted according to EUCAST breakpoints. PCR was used to detect dfrA genes in bacterial isolates (n = 202) and urine samples(n = 94).

Results

Resistance to trimethoprim was observed in 37/124 (29.8%) E. coli and Klebsiella spp. isolates with an MIC₉₀ > 32 mg/L. DfrA genes were detected in 29/37 (78.4%) trimethoprim-resistant isolates. Detection of dfrA was highly sensitive (93.6%) and specific (91.4%) in predicting phenotypic trimethoprim resistance among E. coli and Klebsiella spp. isolates. The dfrA genes analysed were detected using a culture-independent PCR method in 16/94 (17%) urine samples. Phenotypic trimethoprim resistance was apparent in isolates cultured from 15/16 (94%) dfrA-positive urine samples. There was a significant association (P < 0.0001) between the presence of dfrA and trimethoprim resistance in urine samples containing Gram-negative bacteria (Sensitivity = 75%; Specificity = 96.9%; PPV = 93.8%; NPV = 86.1%).

Conclusions

This study demonstrates that molecular detection of dfrA genes is a good indicator of trimethoprim resistance without the need for culture and susceptibility testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02551-9.

Incidence of urinary tract infection following initiation of intermittent catheterization among patients with recent spinal cord injury in Germany and the Netherlands

Objective: To assess incidence of urinary tract infection (UTI) among patients with recent spinal cord injury (SCI) who initiated intermittent catheterization (IC).Design: Retrospective chart review.Setting: Two European SCI rehabilitation centers.Participants: Seventy-three consecutive patients with recent SCI who initiated IC.Outcome measures: Incidence of UTI, using six different definitions, each based on microbiology ± symptomatology ± mention of UTI . Rates were expressed in terms of numbers of UTIs per 100 patient-months (PMs). Attention was focused on first-noted UTI during the three-month follow-up, as assessed with each of the six definitions.Results: Fifty-eight percent of patients (n = 33) met ≥1 definitions for UTI during follow-up (rate: 31.5 UTIs per 100 PMs), ranging from 14% (5.3 per 100 PMs; definition requiring bacteriuria, pyuria, and presence of symptoms) to 45% (22.7 per 100 PMs; definition requiring "mention of UTI"). Ten cases were identified using the definition that required bacteriuria, pyuria, and symptoms, whereas definitions that required bacteriuria and either pyuria or symptoms resulted in the identification of 20-25 cases. Median time to UTI ranged from 42 days ("mention of UTI") to 81 days (definition requiring bacteriuria and ≥100 leukocytes/mm3).Conclusion: Depending on definition, 14% to 45% of patients with recent SCI experience UTI within three months of initiating IC. Definitions requiring bacteriuria and either pyuria or symptoms consistently identified about twice as many cases as those that required all three conditions. Standardizing definitions may help improve detection, treatment, and prevention of UTI within this vulnerable population.

Mixed Sexually Transmitted Infections in Infertile Couples: Empirical Treatment and Influence on Semen Quality

BACKGROUND

Trichomonas vaginalis (TV), Mycoplasma genitalium (MG) and Ureaplasma urealyticum (UU) are common sexually transmitted infections (STIs) that are diagnosed in infertile couples (cps). In cases with their simultaneous presence in a patient (mixed STI, MSTIs), treatment is complicated by the different sensitivity of microorganisms to antibacterial drugs. Moreover, in cases of complicated infections, the empirical treatment should be started before obtaining the results of drug susceptibilities.

OBJECTIVE

The objective of the current study is to find the effective and well-tolerated combination of drugs for the empirical antibacterial treatment of mixed STIs presented by TV, MG and UU in infertile couples. We also aimed to establish the influence of mixed STIs on semen quality.

METHODS

Our prospective study included 154 infertile couples (308 patients) with confirmed symptomatic MSTIs in one of the couples caused by the simultaneous presence of TV, MG and UU. All couples were randomized on three groups for empirical treatment: Group 1 (n=49 cps, 98 pts) who were treated by initial prescribing of anti-trichomoniasis drug Secnidazole, 2.0 g po followed by Azythromycin 500 mg on day 1 continuing by 250 mg on days 2-7; Group 2 (n=52 cps, 104 pts: Secnidazole, 2.0 g po followed by Josamycin 1000 mg bid for 12 days); Group 3 (n=53 cps, 106 pts: Secnidazole, 2.0 g po followed by Moxifloxacin 400 mg once daily for 12 days). The endpoints were clinical and microbiological cure rates as well as the frequency of side-effects in analyzed groups. We determined the basic parameters of the spermogram and Deoxyribonucleic acid (DNA) fragmentation levels in 59 patients with MSTIs before and at the 3rd, 6th and 9th month after pathogens eradication comparing them with results in 63 healthy sperm donors.

RESULTS

After the treatment, clinical cure rates in analyzed groups were 82.6% (Group 1) vs. 96.1% (Group 2) vs. 92.3% (Group 3). Microbiological cure rates (UU+MG) were 73.9% vs. 97.1% vs. 84.5% correspondingly (p<0.05). TV microbiological cure rates were 97.8% vs. 98.0% vs. 96.1% (p>0.05). Side-effects were registered in 28.6% vs. 12.5% vs. 18.9% cases correspondingly (p<0.05). In MSTIs patients, we registered the increasing DNA fragmentation rates, leucocytes count and decreasing semen volume, motility, vitality, sperm concentration, total spermatozoa number and number of spermatozoa with normal morphology. At the 6th month after complete pathogens eradication, these parameters approached normal values.

CONCLUSION

At the present time, the combination of Secnidazole+Josamycin can be considered the most effective and well-tolerated for the empirical treatment in patients with MSTIs presented by TV, MG and UU. Complete eradication of these MSTIs in males improves their semen parameters.

Factors Associated with Acute Community-Acquired Pyelonephritis Caused by Extended-Spectrum β-Lactamase-Producing Escherichia coli

This study aimed to identify the factors associated with the presence of extended-spectrum ß-lactamase-(ESBL) in patients with acute community-acquired pyelonephritis (APN) caused by Escherechia coli (E. coli), with a view of optimising empirical antibiotic therapy in this context. We performed a retrospective analysis of patients with community-acquired APN and confirmed E. coli infection, collecting data related to demographic characteristics, comorbidities, and treatment. The associations of these factors with the presence of ESBL were quantified by fitting multivariate logistic models. Goodness-of-fit and predictive performance were measured using the ROC curve. We included 367 patients of which 51 presented with ESBL, of whom 90.1% had uncomplicated APN, 56.1% were women aged ≤55 years, 33.5% had at least one mild comorbidity, and 12% had recently taken antibiotics. The prevalence of ESBL-producing E. coli was 13%. In the multivariate analysis, the factors independently associated with ESBL were male sex (OR 2.296; 95% CI 1.043-5.055), smoking (OR 4.846, 95% CI 2.376-9.882), hypertension (OR 3.342, 95% CI 1.423-7.852), urinary incontinence (OR 2.291, 95% CI 0.689-7.618) and recurrent urinary tract infections (OR 4.673, 95% CI 2.271-9.614). The area under the ROC curve was 0.802 (IC 95% 0.7307-0.8736), meaning our model can correctly classify an individual with ESBL-producing E. coli infection in 80.2% of cases.

Resistance Trend Estimation Using Regression Analysis to Enhance Antimicrobial Surveillance: A Multi-Centre Study in London 2009-2016

In the last years, there has been an increase of antimicrobial resistance rates around the world with the misuse and overuse of antimicrobials as one of the main leading drivers. In response to this threat, a variety of initiatives have arisen to promote the efficient use of antimicrobials. These initiatives rely on antimicrobial surveillance systems to promote appropriate prescription practices and are provided by national or global health care institutions with limited consideration of the variations within hospitals. As a consequence, physicians' adherence to these generic guidelines is still limited. To fill this gap, this work presents an automated approach to performing local antimicrobial surveillance from microbiology data. Moreover, in addition to the commonly reported resistance rates, this work estimates secular resistance trends through regression analysis to provide a single value that effectively communicates the resistance trend to a wider audience. The methods considered for trend estimation were ordinary least squares regression, weighted least squares regression with weights inversely proportional to the number of microbiology records available and autoregressive integrated moving average. Among these, weighted least squares regression was found to be the most robust against changes in the granularity of the time series and presented the best performance. To validate the results, three case studies have been thoroughly compared with the existing literature: (i) Escherichia coli in urine cultures; (ii) Escherichia coli in blood cultures; and (iii) Staphylococcus aureus in wound cultures. The benefits of providing local rather than general antimicrobial surveillance data of a higher quality is two fold. Firstly, it has the potential to stimulate engagement among physicians to strengthen their knowledge and awareness on antimicrobial resistance which might encourage prescribers to change their prescription habits more willingly. Moreover, it provides fundamental knowledge to the wide range of stakeholders to revise and potentially tailor existing guidelines to the specific needs of each hospital.

Nitrofurantoin Combined With Amikacin: A Promising Alternative Strategy for Combating MDR Uropathogenic Escherichia coli

Urinary tract infections (UTI) are common infections that can be mild to life threatening. However, increased bacterial resistance and poor patient compliance rates have limited the effectiveness of conventional antibiotic therapies. Here, we investigated the relationship between nitrofurantoin and amikacin against 12 clinical MDR uropathogenic Escherichia coli (UPEC) strains both in vitro and in an experimental Galleria mellonella model. In vitro synergistic effects were observed in all 12 test strains by standard checkerboard and time-kill assays. Importantly, amikacin or nitrofurantoin at half of the clinical doses were not effective in the treatment of UPEC infections in the G. mellonella model but the combination therapy significantly increased G. mellonella survival from infections caused by all 12 study UPEC strains. Taken together, these results demonstrated synergy effects between nitrofurantoin and amikacin against MDR UPEC.

Bacterial spectrum and antibiotic resistance of urinary tract infections in patients treated for upper urinary tract calculi: a multicenter analysis

The purpose of this study is to collect information on the bacterial resistance to antibiotics of bacteria isolated from urine cultures of patients treated for upper urinary tract calculi. Data of patients with urinary tract infection and urolithiasis were retrospectively reviewed to collect information on age, gender, stone size, location, hydronephrosis, procedure of stone removal and antibiotic treatment, identification and susceptibility of pathogens, symptoms, and infectious complications. A total of 912 patients from 11 centers in 7 countries (Bulgaria, Greece, Italy, North Macedonia, Spain, and Turkey) were studied. Mean age was 54 ± 16 years and M/F ratio 322/590. Out of 946 microbial isolates, the most common were E. coli, Gram-positive, KES group (Klebsiella, Enterobacter, Serratia), Proteus spp., and P. aeruginosa. Carbapenems, piperacillin/tazobactam and amikacin showed low resistance rates to E. coli (2.5%, 7%, and 3.6%) and Proteus spp. (7.7%, 16%, and 7.4%), but higher rates were observed with Klebsiella spp., P. aeruginosa, and Gram-positive. Fosfomycin had resistance rates less than 10% to E. coli, 23% to KES group, and 19% to Gram-positive. Amoxicillin/clavulanate, cephalosporins, quinolones, and TMP/SMX showed high resistance rates to most bacterial strains. High rates of antibiotic resistance were observed in patients candidate to stone treatment from South-Eastern Europe. The empirical use of antibiotics with low resistance rates should be reserved to the most serious cases to avoid the increase of multidrug resistant bacteria. Basing on our results, carbapenems, piperacillin/tazobactam, and amikacin may be a possible option for empiric treatment of urinary stone patients showing systemic symptoms.

Condition-specific surveillance in health care-associated urinary tract infections as a strategy to improve empirical antibiotic treatment: an epidemiological modelling study

BACKGROUND

Health care-associated urinary tract infection (HAUTI) consists of unique conditions (cystitis, pyelonephritis and urosepsis). These conditions could have different pathogen diversity and antibiotic resistance impacting on the empirical antibiotic choices. The aim of this study is to compare the estimated chances of coverage of empirical antibiotics between conditions (cystitis, pyelonephritis and urosepsis) in urology departments from Europe.

METHODS

A mathematical modelling based on antibiotic susceptibility data from a point prevalence study was carried. Data were obtained for HAUTI patients from multiple urology departments in Europe from 2006 to 2017. The primary outcome of the study is the Bayesian weighted incidence syndromic antibiogram (WISCA) and Bayesian factor. Bayesian WISCA is the estimated chance of an antibiotic to cover the causative pathogens when used for first-line empirical treatment. Bayesian factor is used to compare if HAUTI conditions did or did not impact on empirical antibiotic choices.

RESULTS

Bayesian WISCA of antibiotics in European urology departments from 2006 to 2017 ranged between 0.07 (cystitis, 2006, Amoxicillin) to 0.89 (pyelonephritis, 2009, Imipenem). Bayesian WISCA estimates were lowest in urosepsis. Clinical infective conditions had an impact on the Bayesian WISCA estimates (Bayesian factor > 3 in 81% of studied antibiotics). The main limitation of the study is the lack of local data.

CONCLUSIONS

Our estimates illustrate that antibiotic choices can be different between HAUTI conditions. Findings can improve empirical antibiotic selection towards a personalized approach but should be validated in local surveillance studies.

Decisional Guidance Tool for Antibiotic Prescribing in the Skilled Nursing Facility

OBJECTIVES

To derive weighted-incidence syndromic combination antibiograms (WISCAs) in the skilled nursing facility (SNF). To compare burden of resistance between SNFs in a region and those with and without protocols designed to reduce inappropriate antibiotic use.

DESIGN

Retrospective analysis of microbial data from a regional laboratory.

SETTING

We analyzed 2484 isolates collected at a regional laboratory from a large mixed urban and suburban area from January 1, 2015, to December 31, 2015.

PARTICIPANTS

A total of 28 regional SNFs (rSNFs) and 7 in-network SNFs (iSNFs).

MEASUREMENTS

WISCAs were derived combining Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, and reports restricted to fluoroquinolones, cefazolin, amoxicillin clavulanate, and trimethoprim/sulfamethoxazole.

RESULTS

Pooling the target isolates into WISCAs resulted in an average of 28 of 37 achieving a number greater than 30 with an average of 50 isolates (range = 11-113; >97% urinary). Significant differences were found in antibiotic susceptibility between grouped rSNF data and iSNF data of 75% vs 65% (2.76-11.77; P = .002). The susceptibilities were higher in iSNFs with active antibiotic reduction protocols compared with iSNFs without protocols and rSNFs (effect size = .79 vs .67 and .65, respectively) (I² = 93.33; P < .01). Susceptibilities to cefazolin (95% vs 76%; P < .001) and fluoroquinolones (72% vs 64%; P = .048) were significantly higher in iSNFs with active urinary tract infection protocols as compared with iSNFs without antibiotic reduction protocols.

CONCLUSION

These results suggest that WISCAs can be developed in most SNFs, and their results can serve as indicators of successful antibiotic stewardship programs. J Am Geriatr Soc 68:55-61, 2019.

High prevalence of fluoroquinolone-resistant Escherichia coli strains isolated from urine clinical samples

Background

Fluoroquinolone resistant Escherichia coli isolates have become an important challenge in healthcare settings in Iran. In this study, we have determined Fluoroquinolone resistant E. coli isolates (from both outpatients and inpatients) and evaluated mutations of gyrA and parC within the quinolone resistance-determining regions (QRDR) of these clinical isolates.

Materials and methods

Clinical isolates were recovered from the urine sample of patients with urinary tract infections admitted at Alzahra hospital, Iran, between September and February 2013. We assessed antimicrobial susceptibility of all isolates and determined mutations in QRDR of gyrA and parC genes from 13 fluoroquinolone-resistant isolates by DNA sequencing.

Results

A total of 135 E. coli strains were obtained from 135 patients (91 outpatients and 44 inpatients). The resistance rate of fluoroquinolones (Ciprofloxacin, Norfloxacin and Ofloxacin) among our strains was 45.2%. Two E. coli isolates were shown just a single mutation, but other isolates possessed 2-5 mutations in gyrA and parC genes. Mutations in the QRDR regions of gyrA were at positions Ser83 and Asp87 and parC at positions Ser80, Glu84, Gly78.

Conclusions

Ciprofloxacin is the most common antimicrobial agent used for treating urinary tract infections (UTIs) in healthcare settings in Iran. Accumulation of different substitutions in the QRDR regions of gyrA and parC confers high-level resistance of fluoroquinolones in clinical isolates.

Appropriate empiric antibiotic choices in health care associated urinary tract infections in urology departments in Europe from 2006 to 2015: A Bayesian analytical approach applied in a surveillance study

BACKGROUND

Health care associated urinary tract infections (HAUTI) is a common complicating factor of urological practice. It is unclear what the appropriate empirical antibiotic choices are and how infection control policies (ICP) influence this. The aim of this study is to use probabilistic approaches towards the problem. That is to determine the chances of coverage of empirical antibiotic choices in HAUTIs and their annual trends in Europe. In addition, the impact of departmental self-reported compliance with catheter management and regulated usage of prophylactic antibiotics policies was tested. The estimated chances of coverage of antibiotics and further probabilistic calculations are carried out using the Global Prevalence of Infections in Urology (GPIU) annual surveillance study European data.

METHODS

GPIU is a multi-state annual prevalence study conducted in urology departments to detect patients with HAUTIs, using the Center for Disease Control (CDC) definitions and antimicrobial resistance (AMR). In this analysis; the European cohort from 2005 to 2015 was used. The estimated chance of coverage for each antibiotic choice in HAUTIs was calculated using the Bayesian Weighted Incidence Syndromic Antibiogram (WISCA) approach. Annual trend of the overall cohort and number of appropriate antibiotic choices were estimated. Departments were compared according to their self-reported compliance to ICPs to determine if there was an impact on chances of coverage and appropriate antibiotic choices.

RESULTS

We estimated that in most study years less than half of the single agent antibiotics and all combination options were appropriate for empirical treatment of HAUTIs. Departments with compliance to both ICPs were estimated to have 66%(2006) to 44% (2015) more antibiotic choices compared to departments with complete lack of compliance to the ICPs. In our estimates departments with adherence to a single policy was not superior to departments with complete lack of adherence to ICPs.

CONCLUSIONS

Most single agent choices had limited coverage for HAUTIs and combination choices had improved chance of coverage. Optimal antibiotic selection decision should be part of decision experiments and tested in local surveillance studies. Departments with self-reported compliance to ICPs have more antibiotic choices and details of the compliance should be evaluated in future studies. The analysis herein showed that over the 10-year course there was no clear time trend in the chances of coverage of antibiotics (Bayesian WISCA) in European urology departments.

Assessment of Awareness about Antibiotic Resistance and Practices Followed by Veterinarians for Judicious Prescription of Antibiotics: An Exploratory Study in Eastern Haryana Region of India

The rise of antibiotic resistance and its global outreach has recently become a subject of increasing importance in veterinary research with an objective to reduce the load of antibiotic resistance in dairy farming practices. The present study was designed to analyze antibiotic prescriptions by veterinarians and to evaluate the appropriateness of prescribing behavior in consistent with prudent use of antibiotics. A total of 48 veterinarians were selected randomly from government Veterinary hospitals constituting a total of 48 veterinarians as respondents. The study revealed that most of prescriptions corresponded sound to prudent use of antibiotic and its treatment guidelines. To assess their awareness about antibiotic resistance and its related veterinary practices, an exclusively Awareness Index of antibiotic resistance was developed. It was observed that antibiotics were prescribed in initial encounter of diagnosis; thus, antibiotic conservation practices were found lacking. The ethical awareness of veterinarians was found lacking to establish valid veterinary-client relationship and ensure active involvement of stakeholders. This study largely looks into this angle by unearthing the drug prescribing behavior in order to shape the interdisciplinary research on this biological and profoundly social issue.

Antimicrobial activity of Prunella Vulgaris extracts against multi-drug resistant Escherichia Coli from patients of urinary tract infection

Background and Objective:

Escherichia Coli is the most common etiological agent of UTI and accounts for more then 100, 0000 hospitalization annually. The objective of this study was to investigate the antimicrobial activity of aqueous and ethanolic extracts of Prunella vulgaris against E. coli from urinary tract infection patients.

Methods:

Urine samples of forty four suspected patients from Tertiary Care Hospital Faisalabad were used in this study. Ethanolic and aqueous extracts of Prunella vulgris (PV), a medicinal plant was evaluated for its ability to inhibit the growth of 38 resistant isolates of Escherichia coli strains and compared to Ciprofloxacin, Ofloxacin, Cefixime and Tobramycin by well diffusion method. Minimum inhibitory concentration was measured by using broth micro dilution method.

Results:

PV showed antibacterial activity against Escherichia coli strains, however Tobramycin at 10 microgram (10μg) inhibited the resistant E. coli to a greater extent as compared to other antibiotics and was resistant to twice less number of strains, about 82% of E. coli isolates have MDR pattern.

Conclusion:

Ciprofloxacin has more efficacy than PV and no synergistic effect with extracts of PV. Cefixime is least efficacious against resistant E. coli, however it has synergistic effect with extracts of PV.

National laboratory-based surveillance system for antimicrobial resistance: a successful tool to support the control of antimicrobial resistance in the Netherlands

An important cornerstone in the control of antimicrobial resistance (AMR) is a well-designed quantitative system for the surveillance of spread and temporal trends in AMR. Since 2008, the Dutch national AMR surveillance system, based on routine data from medical microbiological laboratories (MMLs), has developed into a successful tool to support the control of AMR in the Netherlands. It provides background information for policy making in public health and healthcare services, supports development of empirical antibiotic therapy guidelines and facilitates in-depth research. In addition, participation of the MMLs in the national AMR surveillance network has contributed to sharing of knowledge and quality improvement. A future improvement will be the implementation of a new semantic standard together with standardised data transfer, which will reduce errors in data handling and enable a more real-time surveillance. Furthermore, the scientific impact and the possibility of detecting outbreaks may be amplified by merging the AMR surveillance database with databases from selected pathogen-based surveillance programmes containing patient data and genotypic typing data.

A Cohort Study of Risk Factors That Influence Empirical Treatment of Patients with Acute Pyelonephritis

The aim of the current study was to compare community-acquired acute pyelonephritis (CA-APN) with health care-associated acute pyelonephritis (HCA-APN), describe the outcomes, and identify variables that could predict antimicrobial susceptibility. We conducted an observational study that included all consecutive episodes of acute pyelonephritis (APN) in adults during 2014 at a Spanish university hospital. From each episode, demographic data, comorbidities, clinical presentation, microbiological data, antimicrobial therapy, and outcome were recorded. A multivariable logistic regression model was performed to define the variables associated with antimicrobial resistance. A total of 607 patients, 503 (82.9%) with CA-APN and 104 (17.1%) with HCA-APN, were included in the study. Patients with HCA-APN were older than patients with CA-APN (70.4 versus 50.6 years; P < 0.001) and had higher rates of previous urinary tract infections (UTIs) (56.5% versus 24.5%; P < 0.001) and previous antibiotic use (56.8% versus 22.8%; P < 0.001). Escherichia coli was more frequently isolated from patients with CA-APN than from patients with HCA-APN (79.9% versus 50.5%; P < 0.001). The rates of resistance of Escherichia coli strains from CA-APN patients versus HCA-APN patients were as follows: amoxicillin-clavulanic acid, 22.4% versus 53.2% (P = 0.001); cefuroxime, 7.7% versus 43.5% (P = 0.001); cefotaxime, 4.3% versus 32.6% (P < 0.001); ciprofloxacin, 22.8% versus 74.5% (P < 0.001); and co-trimoxazole, 34.5% versus 58.7% (P = 0.003). The site of acquisition, recurrent UTIs, and previous antibiotic use were independent risk factors for antimicrobial resistance. Relapse rates were significantly higher when definitive antimicrobial treatment was not adequate (37.1% versus 9.3% when definitive antimicrobial treatment was adequate; P < 0.001). Our study reflects the rise of resistance to commonly used antibiotics in acute pyelonephritis. In order to choose the adequate empirical antibiotic therapy, risk factors for resistance should be considered.

Clinical and Etiological Structure of Nosocomial Infections in Bulgaria for the Period 2011-2016

Despite their partial diagnosis and registration, nosocomial infections are widespread in Bulgaria and they are of great healthcare, social and economic importance for the society. Statistical processing of official information for the period 2011-2016 shows that the incidence of registered NI among hospitalized patients in Bulgaria is below 1%. In the clinical structure of NI in the above mentioned period, the infections of the surgical site are leading with a prevailing share of 20.67%. S. aureus (19.74%) and E. coli (19.33%) have the highest incidence in the etiological deciphering of infections of the surgical site. Leading etiological agents of lower respiratory tract infections (including pneumonia) in Bulgaria are Acinetobacter spp. (24.12%) and Pseudomonas spp. (20.18%). Urinary tract infections have a relative share of 15.08% in the clinical structure of NI. They are primarily caused by E. coli (28.95%). In bloodstream infection, coagulase-negative staphylococci (S. epidermidis prevailing) are isolated in 30.58% of the cases.

Pharmacokinetics of Intravenous Finafloxacin in Healthy Volunteers

Finafloxacin is a novel fluoroquinolone exhibiting enhanced activity under acidic conditions and a broad-spectrum antibacterial profile. The present study assessed the pharmacokinetic properties and the safety and tolerability of finafloxacin following intravenous infusions. In this mixed-parallel-group, crossover study, healthy male and female volunteers received single ascending doses (18 volunteers, 200 to 1,000 mg) or multiple ascending doses (40 volunteers, 600 to 1,000 mg) of finafloxacin or placebo. Plasma and urine samples were collected by a dense sampling scheme to determine the pharmacokinetics of finafloxacin using a noncompartmental approach. Standard safety and tolerability data were documented. Finafloxacin had a volume of distribution of 90 to 127 liters (range) at steady state and 446 to 550 liters at pseudoequilibrium, indicating the elimination of a large fraction before pseudoequilibrium was reached. Areas under the concentration-time curves and maximum plasma concentrations (geometric means) increased slightly more than proportionally (6.73 to 45.9 μg · h/ml and 2.56 to 20.2 μg/ml, respectively), the terminal elimination half-life increased (10.6 to 17.1 h), and the urinary recovery decreased (44.2% to 31.7%) with increasing finafloxacin doses (single doses of 200 to 1,000 mg). The pharmacokinetic profiles suggested multiphasic elimination by both glomerular filtration and saturable tubular secretion. The values of the parameters were similar for single and multiple administrations. The coefficient of variation for the between-subject variability of exposure ranged from 10% (≤600 mg) to 38% (>600 mg). Adverse events were mild and nonspecific, with no dependence of adverse events on dose or treatment (including placebo) being detected. Despite a relatively high interindividual variability at higher doses, the level of exposure following intravenous administration of finafloxacin appears to be predictable. Individual elimination processes should be evaluated in more detail. Finafloxacin exhibited a favorable safety and tolerability profile. (This study has been registered at ClinicalTrials.gov under registration no. NCT01910883.).

Cost-effectiveness of ceftolozane/tazobactam compared with piperacillin/tazobactam as empiric therapy based on the in-vitro surveillance of bacterial isolates in the United States for the treatment of complicated urinary tract infections

Background

A challenge in the empiric treatment of complicated urinary tract infection (cUTI) is identifying the initial appropriate antibiotic therapy (IAAT), which is associated with reduced length of stay and mortality compared with initial inappropriate antibiotic therapy (IIAT). We evaluated the cost-effectiveness of ceftolozane/tazobactam compared with piperacillin/tazobactam (one of the standard of care antibiotics), for the treatment of hospitalized patients with cUTI.

Methods

A decision-analytic Monte Carlo simulation model was developed to compare the costs and effectiveness of empiric treatment with either ceftolozane/tazobactam or piperacillin/tazobactam in hospitalized adult patients with cUTI infected with Gram-negative pathogens in the US. The model applies the baseline prevalence of resistance as reported by national in-vitro surveillance data.

Results

In a cohort of 1000 patients, treatment with ceftolozane/tazobactam resulted in higher total costs compared with piperacillin/tazobactam ($36,413 /patient vs. $36,028/patient, respectively), greater quality-adjusted life years (QALYs) (9.19/patient vs. 9.13/patient, respectively) and an incremental cost-effectiveness ratio (ICER) of $6128/QALY. Ceftolozane/tazobactam remained cost-effective at a willingness to pay of $100,000 per QALY compared to piperacillin/tazobactam over a range of input parameter values during one-way and probabilistic sensitivity analysis.

Conclusions

Model results show that ceftolozane/tazobactam is likely to be cost-effective compared with piperacillin/tazobactam for the empiric treatment of hospitalized cUTI patients in the United States.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2408-7) contains supplementary material, which is available to authorized users.

The susceptibility to fosfomycin of Gram-negative bacteria isolates from urinary tract infection in the Czech Republic: data from a unicentric study

Background

Against a background of rapid increase of β-lactamase-producing or multi-resistant pathogenic bacteria and the resulting lack of effective antibiotic treatment, some older antibiotics have been tested for new therapeutic uses. One of these is fosfomycin, to which according to studies these resistant bacteria are very sensitive. Our study was designed because there is no data on the fosfomycin susceptibility rate in the Czech Republic.

Method

In this study from January 2013 to June 2014 3295 unique isolates of Gram-negative bacteria which had caused urinary tract infections were examined. The antibiotic susceptibility was measured by disk diffusion test. Both EUCAST and CLSI guidelines criteria (for fosfomycin only) were used for the antibiotic susceptibility evaluation.

Results

The most frequently tested bacterial isolates were Escherichia coli (51.3%, n = 1703), Klebsiella pneumoniae (19.4%, n = 643) and Proteus spp. (11.8%, n = 392). Among all isolates 29.0% (n = 963) were resistant to fluoroquinolones, 11.3% (n = 374) produced extended spectrum β-lactamase and 4.2% (n = 141) produced AmpC β-lactamase. The overall in vitro susceptibility was significantly higher for fosfomycin compared to the other tested per-oral antibiotics (nitrofurantoin, ampicillin, co-trimoxazole, ciprofloxacin and cefuroxime) against all tested Gram-negative rod isolates (excluding Morganella morgani and Acinetobacter spp. isolates). Fosfomycin also remained highly active against those isolates with extended spectrum β-lactamase (ESBL) production (95.8% in Escherichia coli isolates and 85.3% in Klebsiella pneumoniae isolates), unlike other tested per-oral antibiotics, which showed significant (p < 0.0001) susceptibility decrease.

Conclusion

We have confirmed in the Czech Republic the very high susceptibility to fosfomycin trometamol of urinary tract infection pathogens, particularly Gram-negative rods including those producing β-lactamase.

Outcomes of high-dose levofloxacin therapy remain bound to the levofloxacin minimum inhibitory concentration in complicated urinary tract infections

Background

Fluoroquinolones are a guideline-recommended therapy for complicated urinary tract infections, including pyelonephritis. Elevated drug concentrations of fluoroquinolones in the urine and therapy with high-dose levofloxacin are believed to overcome resistance and effectively treat infections caused by resistant bacteria. The ASPECT-cUTI phase 3 clinical trial (ClinicalTrials.gov, NCT01345929 and NCT01345955, both registered April 28, 2011) provided an opportunity to test this hypothesis by examining the clinical and microbiological outcomes of high-dose levofloxacin treatment by levofloxacin minimum inhibitory concentration.

Methods

Patients were randomly assigned 1:1 to ceftolozane/tazobactam (1.5 g intravenous every 8 h) or levofloxacin (750 mg intravenous once daily) for 7 days of therapy. The ASPECT-cUTI study provided data on 370 patients with at least one isolate of Enterobacteriaceae at baseline who were treated with levofloxacin. Outcomes were assessed at the test-of-cure (5–9 days after treatment) and late follow-up (21–42 days after treatment) visits in the microbiologically evaluable population (N = 327).

Results

Test-of-cure clinical cure rates above 90% were observed at minimum inhibitory concentrations ≤4 μg/mL. Microbiological eradication rates were consistently >90% at levofloxacin minimum inhibitory concentrations ≤0.06 μg/mL. Lack of eradication of causative pathogens at the test-of-cure visit increased the likelihood of relapse by the late follow-up visit.

Conclusions

Results from this study do not support levofloxacin therapy for complicated urinary tract infections caused by organisms with levofloxacin minimum inhibitory concentrations ≥4 μg/mL.

Trial registration

ClinicalTrials.gov, NCT01345929 and NCT01345955

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2057-2) contains supplementary material, which is available to authorized users.

An update on the management of urinary tract infections in the era of antimicrobial resistance

Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited therapeutic options. Gram-negative bacteria, specifically Enterobacteriaceae, are common causes of both community-acquired and hospital acquired UTIs. These organisms can acquire genes that encode for multiple antibiotic resistance mechanisms, including extended-spectrum-lactamases (ESBLs), AmpC- β -lactamase, and carbapenemases. The assessment of suspected UTI includes identification of characteristic symptoms or signs, urinalysis, dipstick or microscopic tests, and urine culture if indicated. UTIs are categorized according to location (upper versus lower urinary tract) and severity (uncomplicated versus complicated). Increasing rates of antibiotic resistance necessitate judicious use of antibiotics through the application of antimicrobial stewardship principles. Knowledge of the common causative pathogens of UTIs including local susceptibility patterns are essential in determining appropriate empiric therapy. The recommended first-line empiric therapies for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantion or a 3-g single dose of fosfomycin tromethamine. Second-line options include fluoroquinolones and β-lactams, such as amoxicillin-clavulanate. Current treatment options for UTIs due to AmpC- β -lactamase-producing organisms include fosfomycin, nitrofurantion, fluoroquinolones, cefepime, piperacillin-tazobactam and carbapenems. In addition, treatment options for UTIs due to ESBLs-producing Enterobacteriaceae include nitrofurantion, fosfomycin, fluoroquinolones, cefoxitin, piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, and aminoglycosides. Based on identification and susceptibility results, alternatives to carbapenems may be used to treat mild-moderate UTIs caused by ESBL-producing Enterobacteriaceae. Ceftazidime-avibactam, colistin, polymixin B, fosfomycin, aztreonam, aminoglycosides, and tigecycline are treatment options for UTIs caused by carbapenem-resistant Enterobacteriaceae (CRE). Treatment options for UTIs caused by multidrug resistant (MDR)-Pseudomonas spp. include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, aminoglycosides, colistin, ceftazidime-avibactam, and ceftolozane-tazobactam. The use of fluoroquinolones for empiric treatment of UTIs should be restricted due to increased rates of resistance. Aminoglycosides, colistin, and tigecycline are considered alternatives in the setting of MDR Gram-negative infections in patients with limited therapeutic options.

Antimicrobial Activities of Ceftazidime-Avibactam and Comparator Agents against Gram-Negative Organisms Isolated from Patients with Urinary Tract Infections in U.S. Medical Centers, 2012 to 2014

A total of 7,272 unique patient clinical isolates were collected from 71 U.S. medical centers from patients with urinary tract infections in 2012 to 2014 and tested for susceptibility to ceftazidime-avibactam and comparators by broth microdilution methods. Ceftazidime-avibactam inhibited >99.9% of all Enterobacteriaceae at the susceptible breakpoint of ≤8 μg/ml (there were only three nonsusceptible strains). Ceftazidime-avibactam was also active against Pseudomonas aeruginosa isolates (MIC50, 2 μg/ml; MIC90, 4 μg/ml; 97.7% susceptible), including many isolates not susceptible to meropenem, ceftazidime, and/or piperacillin-tazobactam.

High prevalence of multidrug-resistance uropathogenic Escherichia coli strains, Isfahan, Iran

BACKGROUND AND OBJECTIVES

Urinary tract infection (UTI) is one of the most frequent infectious diseases and can occur in all age groups. Escherichia coli is the main cause of this infection. Multiple resistances to antimicrobial agents are increasing quickly in E. coli isolates and may complicate therapeutic strategies for UTI. The aim of this study was to determine the antibiotic resistance pattern and the multidrug-resistance (MDR) phenotypes in uropathogenic E. coli (UPEC).

MATERIALS AND METHODS

A total of 135 UPEC isolates were collected from both outpatients (91 isolates) and inpatients (44 isolates) between September, 2012 and February, 2013. In order to determine the MDR among UPEC isolates, we have tested 15 antimicrobial agents and antibiotic susceptibility was done by Kirby-Bauer disk diffusion method.

RESULTS

The percentage of MDR isolates (resistant to at least three drug classes such as aminoglycosides, fluoroquinolones, penicillins, cephalosporins, or carbapenems) was 68% in the inpatients and 61% in the outpatients. Antibiotic resistance to ampicillin, ceftazidim, nalidixic acid, and trimethoprim/sulfamethoxazole were higher than 50%. Amikacin, nitrofurantoin, and gentamicin showed markedly greater activity (89.1%, 85.9%, and 82.4% sensitivity, respectively) than other antimicrobial agents. Resistance to meropenem did show either in outpatients or in inpatients.

INTERPRETATION AND CONCLUSIONS

The high prevalence of drug resistance among UTI patients calls for continuous monitoring of the incidence of drug resistance for appropriate empiric selection of antibiotic therapy. Empirical treatment of UTIs should be relied on susceptibility patterns from local studies.