Risk factors of multidrug-resistant bacteria in community-acquired urinary tract infections

BackgroundUrinary tract infections (UTIs) are one of the most seen infection among community.ObjectivesIn this cross-sectional study we aimed to investigate the risk factors of multidrug-resistant (MDR) bacteria that caused community-acquired UTI (CA-UTI).MethodsConsecutive patients admitted to the Urology and Infectious Diseases policlinics with the diagnosis of CA-UTI were included in the study. A standard form including possible predisposing factors for MDR bacteria was applied.ResultsIn total, 240 patients (51.3% females) were enrolled in the study. The mean age of participants were 59.8 ± 18.3 years old. Escherichia coli (n =166; 69.2%)was the most frequently isolated bacteria and its incidence was higher in females than in males (p=0.01). In total, 129 (53.8%) of the identified pathogens were MDR bacteria. According to multivariate analysis, the use of antibiotics three or more times increased the risk of infection with MDR bacteria by 4.6 times, the history of urinary tract infection in the last 6 months by 2 times, being male and over 65 years old by 3 times.ConclusionDoctors should consider prescribing broad-spectrum antibiotics in patients with severe UTIs with a history of UTI, advanced age, male gender, and multiple antibiotic usage, even if they have a CA-UTI.     

Effect of outpatient antibiotics for urinary tract infections on antimicrobial resistance among commensal Enterobacteriaceae: a multinational prospective cohort study

ObjectivesWe quantified the impact of antibiotics prescribed in primary care for urinary tract infections (UTIs) on intestinal colonization by ciprofloxacin-resistant (CIP-RE) and extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), while accounting for household clustering.MethodsProspective cohort study from January 2011 to August 2013 at primary care sites in Belgium, Poland and Switzerland. We recruited outpatients requiring antibiotics for suspected UTIs or asymptomatic bacteriuria (exposed patients), outpatients not requiring antibiotics (non-exposed patients), and one to three household contacts for each patient. Faecal samples were tested for CIP-RE, ESBL-PE, nitrofurantoin-resistant Enterobacteriaceae (NIT-RE) and any Enterobacteriaceae at baseline (S1), end of antibiotics (S2) and 28 days after S2 (S3).ResultsWe included 300 households (205 exposed, 95 non-exposed) with 716 participants. Most exposed patients received nitrofurans (86; 42%) or fluoroquinolones (76; 37%). CIP-RE were identified in 16% (328/2033) of samples from 202 (28%) participants. Fluoroquinolone treatment caused transient suppression of Enterobacteriaceae (S2) and subsequent two-fold increase in CIP-RE prevalence at S3 (adjusted prevalence ratio (aPR) 2.0, 95% CI 1.2–3.4), with corresponding number-needed-to-harm of 12. Nitrofurans had no impact on CIP-RE (aPR 1.0, 95% CI 0.5–1.8) or NIT-RE. ESBL-PE were identified in 5% (107/2058) of samples from 71 (10%) participants, with colonization not associated with antibiotic exposure. Household exposure to CIP-RE or ESBL-PE was associated with increased individual risk of colonization: aPR 1.8 (95% CI 1.3–2.5) and 3.4 (95% CI 1.3–9.0), respectively.ConclusionsThese findings support avoidance of fluoroquinolones for first-line UTI therapy in primary care, and suggest potential for interventions that interrupt household circulation of resistant Enterobacteriaceae.     

The association of adequate empirical treatment and time to recovery from bacteraemic urinary tract infections: a retrospective cohort study

Our objective was to evaluate whether patients with bacteraemic urinary tract infection (UTI) who receive inadequate empirical therapy have worse outcomes than those with adequate therapy. This was a retrospective cohort study of patients with bacteraemic UTI. The exposure variable was adequate versus inadequate empirical antibiotic therapy (AEAT versus IEAT) within 24 h of culture collection. Primary endpoint was time to cure. The primary analysis used propensity score models with inverse probability of treatment weights. A secondary Cox proportional hazards modelling approach was used to test the robustness of this finding, and to evaluate other patient and pathogen predictors of time to cure. Of 469 patients with bacteraemic UTI, 368 (78.5%) received AEAT. There was no significant difference in mortality between those receiving AEAT and those receiving IEAT (adjusted OR 0.86, 95%CI 0.47–1.58). Receipt of AEAT had no association with time to cure (HR 0.93, 95%CI 0.73–1.19, p 0.55) or time to normalization of individual clinical variables. Cox proportional hazards modelling revealed that longer time to cure was associated with liver disease (HR 0.25, 95%CI 0.08–0.76, p 0.015), prior stroke (HR 0.73, 95%CI 0.54–0.99, p 0.044), empirical receipt of piperacillin–tazobactam (HR 0.77, 95%CI 0.59–0.99, p 0.044), qSOFA score >1 (HR 0.68, 95%CI 0.55–0.84, p < 0.001), and hospital-onset UTI (HR 0.53, 95%CI 0.39–0.71, p < 0.001). In conclusion, we found no association between AEAT and time to cure for patients with bacteraemic UTI. It may be appropriate to accept a higher risk threshold when choosing empirical antibiotic regimens, even in centres with high rates of resistant uropathogens.     

The additional value of blood cultures in patients with complicated urinary tract infections

We evaluated 800 hospitalized patients with a complicated urinary tract infection, from whom both a blood and a urine culture were obtained on the first day of antibiotic treatment. Urine cultures were positive in 70% of patients, and blood cultures were positive in 29%. In 7% of patients, uropathogens caused bacteraemia with a pathogen that was not isolated from urine. Receiving antibiotic therapy at the moment of hospitalization was the only factor independently associated with discordant culture results (OR, 2.06; 95% CI, 1.18–3.61). For those receiving antibiotics at the moment of hospitalization, blood cultures have additional diagnostic value over urine cultures.     

Antibiotic resistance of Escherichia coli from community-acquired urinary tract infections in relation to demographic and clinical data

This prospective study determined the antibiotic susceptibility of 164 isolates of Escherichia coli from the urine of 164 patients (112 female, 52 male; mean age of 54.12 years) with community-acquired urinary tract infection (UTI). Half of the isolates were from uncomplicated UTI and half from complicated UTI (52 males and 34 females). Overall, 57.3% of isolates were resistant to ampicillin, 25% to co-trimoxazole, 20.1% to nalidixic acid, 14% to norfloxacin and ciprofloxacin, and 0% to fosfomycin and nitrofurantoin. Of the 82 isolates from complicated UTI, 16 (19.5%) were resistant to norfloxacin and ciprofloxacin, compared with seven (8.5%) from uncomplicated UTI (p 0.043). Isolates from patients aged >50 years were significantly more resistant than those from patients aged <50 years for nalidixic acid (p 0.007) and the fluoroquinolones tested (p 0.015). Resistance to fluoroquinolones was 25% (13/52) in males and 9% (10/112) in females (p 0.006). For patients with and without previous antimicrobial therapy, there was a significant difference only for resistance to nalidixic acid (p < 0.001) and the fluoroquinolones (p 0.011). There were adequate susceptibility rates to fosfomycin, nitrofurantoin and the fluoroquinolones for empirical use in the treatment of acute uncomplicated UTI. In order to interpret cumulative susceptibility data from the primary healthcare setting, it is necessary to take into account the type of UTI (uncomplicated vs. complicated), previous antimicrobial therapy, and the sex and age of each patient.     

Fluoroquinolone use for uncomplicated urinary tract infections in women: a retrospective cohort study

ObjectivesThe United States Food & Drug Administration released an advisory in 2016 that fluoroquinolones be relegated to second-line agents for uncomplicated urinary tract infections (UTIs) given reports of rare but serious side effects; similar warnings have followed from Health Canada and the European Medicines Agency. The objective was to determine whether alternative non-fluoroquinolone agents are as effective as fluoroquinolones in the treatment of UTIs.MethodsWe conducted a retrospective population-based cohort study using administrative health data from six Canadian provinces. We identified women (n = 1 585 997) receiving antibiotic treatment for episodes of uncomplicated UTIs (n = 2 857 243) between January 1 2005 and December 31 2015. Clinical outcomes within 30 days from the initial antibiotic dispensation were compared among patients treated with a fluoroquinolone versus non-fluoroquinolone agents. High-dimensional propensity score adjustments were used to ensure comparable treatment groups and to minimize residual confounding.ResultsFluoroquinolone use for UTI declined over the study period in five of six Canadian provinces and accounted for 22.3–48.5% of treatments overall. The pooled effect across the provinces indicated that fluoroquinolones were associated with fewer return outpatient visits (OR 0.89, 95%CI 0.87–0.92), emergency department visits (OR 0.74, 95%CI 0.61–0.89), hospitalizations (OR 0.83, 95%CI 0.77–0.88), and repeat antibiotic dispensations (OR 0.77, 95%CI 0.75–0.80) within 30 days.ConclusionsFluoroquinolones are associated with improved clinical outcomes among women with uncomplicated UTIs. This benefit must be weighed against the risk of fluoroquinolone resistance and rare but serious fluoroquinolone side effects when selecting first-line treatment for these patients.     

Active surveillance of antibiotic resistance prevalence in urinary tract and skin infections in the outpatient setting

The aim of the study was to evaluate the need for active surveillance of antibiotic resistance in ambulatory infections. We measured the prevalence of antibiotic resistance in urinary tract infections (UTIs) (n = 1018) and skin infections (n = 213) diagnosed in outpatients between September 2008 and February 2009 in the Canton of Bern, Switzerland. Samples were stratified into ‘solicited’ (diagnostic work-up for study purpose only) and ‘routine’ (diagnostic work-up as part of standard care). Susceptibility patterns were compared for 463 Escherichia coli isolates from UTIs (231 solicited; 232 routine) and 87 Staphylococcus aureus isolates from skin infections (35 solicited; 52 routine). Overall, E. coli showed higher susceptibility to ampicillin, amoxicillin–clavulanic acid and norfloxacin in solicited than in routine samples. Among 15–45-year-old patients, susceptibility rates were comparable between solicited and routine samples for all antibiotics except for amoxicillin–clavulanic acid. However, among patients >45 years old, isolates from routine samples showed lower susceptibility to all β-lactams tested and quinolones than those from solicited samples. Extended-spectrum β-lactamase (ESBL)-producing E. coli isolates were rare (solicited, 0.4%; routine, 1.7%; p 0.4). Susceptibility patterns of S. aureus were comparable between solicited and routine samples. Therefore, in the outpatient setting, susceptibility rates for E. coli isolates differ by indication for urinary culture and age. Surveillance based on samples taken during standard care may underestimate susceptibility rates for uncomplicated infections, especially among the elderly. Reports of resistance data should include age stratification.     

Unique blood culture for diagnosis of bloodstream infections in emergency departments: a prospective multicentre study

Detection of microorganisms by blood cultures (BCs) is essential in managing patients with bacteraemia. Rather than the number of punctures, the volume of blood drawn is considered paramount in efficient and reliable detection of microorganisms. We performed a 1-year prospective multicentre study in adult emergency departments of three French university hospitals comparing two methods for BCs: a unique blood culture (UBC) collecting a large volume of blood (40 mL) and the standard method of multiple blood cultures (MBC). The performances of both methods for bacterial contamination and efficient microbial detection were compared, each patient serving as his own control. Amongst the 2314 patients included, three hundred were positive for pathogens (n = 245) or contaminants (n = 55). Out of the 245 patients, 11 were positive for pathogens by UBC but negative by MBC and seven negative by UBC but positive by MBC (p 0.480). In the subgroup of 137 patients with only two BCs, UBC was superior to MBC (p 0.044). Seven and 17 patients had contaminated BCs by UBC and MBC only, respectively (p 0.062). Considering the sums of pathogens missed and contaminants, UBC significantly outperformed MBC (p 0.045). Considering the complete picture of cost savings, efficient detection of microorganisms and decrease in contaminations, UBC offers an interesting alternative to MBC.     

超敏C反应蛋白和尿路感染信息在尿路感染诊断中的应用

目的探讨超敏C反应蛋白（hs-CRP）及尿路感染信息（UTI-Info）对尿路感染（UTI）的诊断价值。方法对380例疑似UTI患者的尿标本进行尿培养,用UF-1000i全自动尿液有形成分分析仪测定白细胞数（WBC）及细菌数（BACT）,得到UTI-Info;用AU2700全自动生化分析仪测定静脉血hs-CRP含量;以细菌定量培养结果为标准对照,评估hs-CRP、UTI-Info、hs-CRP＋UTI-Info诊断UTI的灵敏度、特异性、诊断符合率等。结果除污染标本外,余下360份标本中,细菌培养结果阳性有102份,阳性率为28.3%。以细菌培养为参考方法,hs-CRP诊断UTI的灵敏度、特异性、诊断符合率分别为85.3%、70.9%、75.0%;UTI-Info诊断UTI的灵敏度、特异性、诊断符合率分别为76.5%、84.5%、82.2%;hs-CRP＋UTI-Info诊断UTI的灵敏度、特异性、诊断符合率分别为70.6%、97.3%、89.7%。结论 hs-CRP联合UTI-Info能快速诊断UTI并能提高特异性及诊断的准确性。     

Integrons and multidrug resistance among Escherichia coli causing community-acquired urinary tract infection in southern India

Antimicrobial resistance genes are often clustered in integrons, genetic elements capable of recombination. There is a paucity of data on the prevalence and role of integrons from community-acquired infections in developing countries where resistance to co-trimoxazole is high. We determined the prevalence of integrons among Escherichia coli causing community-acquired urinary tract infection (UTI). Consecutive isolates of E. coli obtained from UTI of pregnant women at the Christian Medical College Hospital, Vellore, India, during 2002 were included. All isolates were tested for susceptibility to 16 antimicrobials using the disc diffusion method and for integrons of classes 1 and 2 by PCR. Of the 58 isolates tested, 28 (48.3%) were resistant to co-trimoxazole and trimethoprim. All these isolates carried integrons. Three additional isolates were sulfonamide resistant but integron negative. Class 1 integrons were present in 21 (36.2%) isolates. Resistance to ampicillin (p=0.000), nalidixic acid (p=0.001), chloramphenicol (p=0.02), tetracycline (p=0.004) and gentamicin (p=0.02) was significantly more common in isolates with integrons. DNA sequencing of two isolates with integrons showed the presence of aadA, dfr1 and dfr7 genes. This study demonstrated that integrons are widely prevalent in India and that they might play a role in multidrug resistance in E. coli from community-acquired UTI.     

Microbial risk factors for treatment failure of pivmecillinam in community-acquired urinary tract infections caused by ESBL-producing Escherichia coli

The aim of this study was to identify microbial risk factors for treatment failure of pivmecillinam in community-acquired urinary tract infections (ca-UTIs) caused by ESBL-producing Escherichia coli. Eighty-nine ESBL-producing E. coli isolated from women suffering from ca-UTIs were included. The susceptibilities to mecillinam were determined using MIC gradient strip. Whole genome sequencing was performed on a MiSeq platform, and genome assembly was performed using SPAdes v3.11.0. Neither mecillinam MICs nor ESBL genotypes were associated with treatment outcome of patients treated with pivmecillinam. Specific STs, however, showed significant differences in treatment outcome. Patients infected with ST131 were more likely to experience treatment failure compared to patients infected with non-ST131 (p 0.02) when adjusted for pivmecillinam dose, mecillinam MIC and severity of infection. Patients infected with ST69 were more often successfully treated compared to patients infected with non-ST69 (p 0.04). Patients infected with bla_CTX-M-15 ST131 strains were more likely to experience treatment failure than those infected with non-bla_CTX-M-15 ST131 strains (p 0.02). The results suggest that specific STs are associated with the clinical efficacy of pivmecillinam. Further studies with a larger number of strains, including a larger number of mecillinam resistant strains, are needed to confirm these results.     

Urinary tract infections in the critical care unit: A brief review

The use of indwelling catheters in the Critical Care Units (CCUs) has a major role in determining the incidence and the morbidity as well as mortality from hospital-acquired urinary tract infections (UTIs). Instituting evidence-based protocols can significantly reduce both the prevalence of indwelling catheterization as well as the incidence of hospital-acquired UTIs. The prevalence of catheter-associated urinary tract infections (CAUTIs) in the CCUs is directly linked to the widespread use of indwelling catheters in these settings. CAUTIs result in significant cost escalation for individual hospitals as well as the healthcare system as a whole. A UTI is an inflammatory response to colonization of the urinary tract, most commonly by bacteria or fungi. A UTI should be differentiated from the mere detection of bacteria in the urinary tract. This condition, referred to as asymptomatic bacteriuria, is common and does not require treatment, especially in the patient with an indwelling urinary catheter. A CAUTI occurs when a patient with an indwelling urinary catheter develops 2 or more signs or symptoms of a UTI such as hematuria, fever, suprapubic or flank pain, change in urine character, and altered mental status. CAUTI is classified as a complicated UTI. The current review highlights the important management issues in critical care patients having CAUTI. We performed a MEDLINE search using combinations of keywords such as urinary tract infection, critical care unit and indwelling urinary catheter. We reviewed the relevant publications with regard to CAUTI in patients in CCU.     

Antibiogram of nosocomial urinary tract infections in Felege Hiwot referral hospital, Ethiopia

Background

Nosocomial infections increase the cost of medical care, extend hospital stay and reflect on the morbidity and mortality of the admitted patients. Urinary tract infections (UTIs) are one of the most common nosocomial infections in humans.

Objectives

To determine the prevalence and antibiogram of nosocomial UITs from a referral hospital.

Methods

A cross-sectional study was conducted on 1 254 patients from April to August 2010. Antimicrobial susceptibility tests were done using disc diffusion technique as per the standard of Kirby-Bauer method.

Results

Of the 1 254 patients, 118 (9.4%) developed nosocomial UTIs. Seventy three (61.9%) and 44 (37.1%) of the bacterial isolates were gram negative and gram positive, respectively. One patient had a mixed infection. E. coli, S.aureus and K. pneumonia were the most predominant isolates. Gender, catheterization and pre-operative antimicrobial prophylaxis and underlying diseases were significantly associated with the occurrence of nosocomial UTIs (p=0.001). Most bacterial isolates showed high resistance rates (>80%) to ampicillin, amoxicillin/clavulanic acid, chloramphenicol and cloxacillin.

Conclusion

Catheterization and preoperative antibiotic prophylaxis were found to be the risk factors for nosocomial infection. Effective infection prevention measures should be in place to reduce the prevalence of nosocomial UTIs.     

Single-dose ciprofloxacin versus 3 days of norfloxacin in uncomplicated urinary tract infections in women

A double-blind, randomized controlled study to evaluate the efficacy and safety of a single dose of 500 mg of ciprofloxacin versus 3 days 400 mg twice-daily of norfloxacin in uncomplicated urinary tract infection in women was designed. Patients underwent four visits: baseline, and at 3, 7 and 28 days. The main efficacy variables were clinical and microbiological outcome at day 7. Analyses on both valid patients and intention-to-treat populations were performed. Two hundred and twenty-six patients (114 receiving ciprofloxacin and 112 receiving norfloxacin) were considered valid for efficacy evaluation. Bacteriologic cure was 91.2% in the ciprofloxacin group and 91.9% in the norfloxacin group. Clinical resolution was 91.2 and 93.8%, respectively. Both treatments were equally efficacious ( P  = 0.016).     

Utility of prior cultures in predicting antibiotic resistance of bloodstream infections due to Gram-negative pathogens: a multicentre observational cohort study

ObjectivesAppropriate empiric antibiotic therapy in patients with bloodstream infections due to Gram-negative pathogens can improve outcomes. We evaluated the utility of prior microbiologic results for guiding empiric treatment in Gram-negative bloodstream infections.MethodsWe conducted a multicentre observational cohort study in two large health systems in Canada and the United States, including 1832 hospitalized patients with Gram-negative bloodstream infection (community, hospital and intensive care unit acquired) from April 2010 to March 2015.ResultsAmong 1832 patients with Gram-negative bloodstream infection, 28% (n = 504) of patients had a documented prior Gram-negative organism from a nonscreening culture within the previous 12 months. A most recent prior Gram-negative organism resistant to a given antibiotic was strongly predictive of the current organism's resistance to the same antibiotic. The overall specificity was 0.92 (95% confidence interval (CI) 0.91–0.93), and positive predictive value was 0.66 (95% CI 0.61–0.70) for predicting antibiotic resistance. Specificities and positive predictive values ranged from 0.77 to 0.98 and 0.43 to 0.78, respectively, across different antibiotics, organisms and patient subgroups. Increasing time between cultures was associated with a decrease in positive predictive value but not specificity. An heuristic based on a prior resistant Gram-negative pathogen could have been applied to one in four patients and in these patients would have changed therapy in one in five.ConclusionsIn patients with a bloodstream infection with a Gram-negative organism, identification of a most recent prior Gram-negative organism resistant to a drug of interest (within the last 12 months) is highly specific for resistance and should preclude use of that antibiotic.     

Containing antibiotic resistance: decreased antibiotic-resistant coliform urinary tract infections with reduction in antibiotic prescribing by general practices.

BACKGROUND: GPs are urged to prescribe antibiotics less frequently, despite lack of evidence linking reduced antibiotic prescribing with reductions in resistance at a local level. AIM: To investigate associations between changes in antibiotic dispensing and changes in antibiotic resistance at general-practice level. DESIGN OF STUDY: Seven-year study of dispensed antibiotics and antibiotic resistance in coliform isolates from urine samples routinely submitted from general practice. SETTING: General practices in Wales. METHOD: Multilevel modelling of trends in resistance to ampicillin and trimethoprim, and changes in practice total antibiotic dispensing and amoxicillin and trimethoprim dispensing. RESULTS: The primary analysis included data on 164 225 coliform isolates from urine samples submitted from 240 general practices over the 7-year study period. These practices served a population of 1.7 million patients. The quartile of practices that had the greatest decrease in total antibiotic dispensing demonstrated a 5.2% reduction in ampicillin resistance over the 7-year period with changes of 0.4%, 2.4%, and -0.3% in the other three quartiles. There was a statistically significant overall decrease in ampicillin resistance of 1.03% (95% confidence interval [CI] = 0.37 to 1.67%) per decrease of 50 amoxicillin items dispensed per 1000 patients per annum. There were also significant reductions in trimethoprim resistance in the two quartiles of practices that reduced total antibiotic dispensing most compared with those that reduced it least, with an overall decrease in trimethoprim resistance of 1.08% (95% CI = 0.065 to 2.10%) per decrease of 20 trimethoprim items dispensed per 1000 patients per annum. Main findings were confirmed by secondary analyses of 256 370 isolates from 527 practices that contributed data at some point during the study period. CONCLUSION: Reducing antibiotic dispensing at general-practice level is associated with reduced local antibiotic resistance. These findings should further encourage clinicians and patients to use antibiotics conservatively.     

Attributable mortality of antibiotic resistance in gram-negative infections in the Netherlands: a parallel matched cohort study

ObjectivesAntibiotic resistance in Gram-negative bacteria has been associated with increased mortality. This was demonstrated mostly for third-generation cephalosporin-resistant (3GC-R) Enterobacterales bacteraemia in international studies. Yet, the burden of resistance specifically in the Netherlands and created by all types of Gram-negative infection has not been quantified. We therefore investigated the attributable mortality of antibiotic resistance in Gram-negative infections in the Netherlands.MethodsIn eight hospitals, a sample of Gram-negative infections was identified between 2013 and 2016, and separated into resistant and susceptible infection cohorts. Both cohorts were matched 1:1 to non-infected control patients on hospital, length of stay at infection onset, and age. In this parallel matched cohort set-up, 30-day mortality was compared between infected and non-infected patients. The impact of resistance was then assessed by dividing the two separate risk ratios (RRs) for mortality attributable to Gram-negative infection.ResultsWe identified 1954 Gram-negative infections, of which 1190 (61%) involved Escherichia coli, 210 (11%) Pseudomonas aeruginosa, and 758 (39%) bacteraemia. Resistant Gram-negatives caused 243 infections (12%; 189 (78%) 3GC-R Enterobacterales, nine (4%) multidrug-resistant P. aeruginosa, no carbapenemase-producing Enterobacterales). Subsequently, we matched 1941 non-infected controls. After adjustment, point estimates for RRs comparing mortality between infections and controls were similarly higher than 1 in case of resistant infections and susceptible infections (1.42 (95% confidence interval 0.66–3.09) and 1.32 (1.06–1.65), respectively). By dividing these, the RR reflecting attributable mortality of resistance was calculated as 1.08 (0.48–2.41).ConclusionsIn the Netherlands, antibiotic resistance did not increase 30-day mortality in Gram-negative infections.