Treatment of uncomplicated urinary tract infections in an era of increasing antimicrobial resistance

In the past few years, notable advances have occurred in our understanding of the epidemiology and clinical importance of drug resistance among uropathogens that cause uncomplicated urinary tract infections (UTIs) or cystitis. Guidelines recommend trimethoprim-sulfamethoxazole for empirical treatment of uncomplicated UTI unless trimethoprim-sulfamethoxazole resistance in a community exceeds 10% to 20%. The rationale for this 10% to 20% cutoff appears to be related to clinical and economical considerations and to concerns about the emergence of fluoroquinolone-resistant bacteria. In patients with uncomplicated UTIs caused by uropathogens resistant to trimethoprim-sulfamethoxazole who were treated with this drug combination, clinical outcomes were clarified recently and found to be suboptimal (<60% clinical cure). Following guidelines for empirical treatment of uncomplicated UTIs is problematic. Surveillance of antimicrobial resistance among uropathogens that cause uncomplicated UTIs is performed rarely. Hospital antibiograms provide data on resistance among bacteria that cause community-associated UTIs; however, antibiograms overestimate drug resistance among uropathogens that cause UTIs and may mislead clinicians about the prevalence of local resistance. We review options for management of uncomplicated UTIs in light of these considerations.     

Antimicrobial resistance among uropathogens that cause acute uncomplicated cystitis in women in Hong Kong: a prospective multicenter study in 2006 to 2008

A prospective multicenter study was conducted to assess the epidemiology of antimicrobial resistance among uropathogens causing uncomplicated cystitis. Adult women with clinical diagnosis of uncomplicated cystitis were enrolled from 54 participating centers distributed all over Hong Kong during 2006 to 2008. A positive urine culture was found in 59.5% (352/592) patients. The patients had mean age of 44.9 years, and most (89.2%) were otherwise healthy. The most prevalent causative organism was Escherichia coli (77%), followed by other Enterobacteriaceae (14.2%), staphylococci (5.1%), and other Gram-positive bacteria (3.7%). The resistance rates of E. coli to co-trimoxazole and ciprofloxacin were 29.5% and 12.9%, respectively, and 14 isolates (5.2%) were confirmed as extended-spectrum β-lactamase (ESBL) producers. Of the ESBL producers, molecular studies showed CTX-M-14, CTX-M-24, or CTX-M-9. Nitrofurantoin and fosfomycin were active against >90% of the isolates, regardless of resistance phenotypes for other drugs. Pulsed-field gel electrophoresis of representative isolates showed that the antibiotic-resistant strains were genetically diverse. Patients with history of recent antibiotic use were significantly more likely to have infection by E. coli with co-trimoxazole resistance (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.4–5.7; P = 0.003) and ciprofloxacin resistance (OR, 2.5; 95% CI, 1.1–5.8; P = 0.03). Knowledge of the resistance data and risk factors could inform better use of antibiotics for empiric therapy for acute uncomplicated cystitis.     

The resistance ofEscherichia coli strains isolated from community-acquired urinary tract infections

Urinary tract infections (UTIs) are the most common infections caused byEscherichia coli. Most recent research demonstrates that antibiotic resistance has reached a critical point throughout the world, as increased use of antibiotics among nonhospitalized patients encourages the growth of drug-resistant pathogens among that population. The goal of this study was to determine the antimicrobial drug resistance ofE coli strains isolated from community-acquired UTIs in 5 different regions in Turkey. The minimum inhibitory concentrations of ciprofloxacin, gentamicin, sulfamethoxazole, trimethoprim, trimethoprim-sulfamethoxazole, and ampicillin and forE coli were determined with the agar dilution method. Among the 480 strains isolated, 8.3% were resistant to ciprofloxacin, 3.3% to gentamicin, 35.4% to sulfamethoxazole, 33.3% to trimethoprim, 27.9% to trimethoprim-sulfamethoxazole, and 40.8% to ampicillin. These results show that the antibiotics currently most effective againstE coli are ciprofloxacin and gentamicin. Local epidemiologic trends should be considered when prescribing antibacterial therapy. More research in bacterial gene mapping will be necessary to elucidate the influence of regional antimicrobial drug use and resistance in epidemiologic trends among the general population.     

Evaluating Empiric Therapy for Acute Uncomplicated Cystitis in the Outpatient Setting: A Retrospective Cohort Study

ObjectivesTo evaluate the empiric therapy prescribed for acute uncomplicated cystitis in the outpatient setting (emergency department and ambulatory care clinics) and to characterize uropathogens for discordance between the therapy prescribed and susceptibility.MethodsA retrospective review was conducted at an inner-city emergency department and multiple clinics to evaluate the empiric therapy prescribed and the uropathogens isolated from culture for patients with acute uncomplicated cystitis.ResultsA total of 144 urine cultures were included. Among the patients, 53.4% were empirically prescribed cephalexin, 20.1% ciprofloxacin, 11% nitrofurantoin, and 8.3% trimethoprim/sulfamethoxazole. The most common uropathogen was Escherichia coli (72.4%), followed by Streptococcus agalactiae (7.6%) and Klebsiella pneumoniae (4.8%). Of the 107 E. coli isolates, 9 were extended spectrum beta-lactamase–producing. E. coli antimicrobial susceptibilities were as follows: ceFAZolin (97%), nitrofurantoin (96%), cefTRIAXone (91%), ciprofloxacin (87%), and trimethoprim-sulfamethoxazole (59%). The concordance rates with the Infectious Diseases Society of America treatment guidelines for acute uncomplicated cystitis and local resistance patterns were as follows: empiric therapy prescribed (70%), dosing of empiric therapy (77%), and duration of empiric therapy (22%). For empiric therapy prescribed and susceptibility mismatch, 5.6% of the isolates were not susceptible to therapy, 76.4% were susceptible to therapy, 14% did not have susceptibilities, and 4.2% did not receive therapy.ConclusionsMost of the cases of acute uncomplicated cystitis at the subject institution can be managed safely and effectively with nitrofurantoin or first-generation cephalosporins. Institutions should use national guidelines in conjunction with local resistance and prescribing patterns to improve antibiotic prescribing in the outpatient setting.     

Urinary tract infection: traditional pharmacologic therapies

Urinary tract infections (UTIs) are common bacterial infections, particularly in women. Antimicrobial therapy is seldom indicated for asymptomatic infection, but antimicrobial therapy is usually indicated for amelioration of symptoms. Management of acute uncomplicated UTI (cystitis) is generally straightforward, with a predictable distribution of uropathogens isolated. First-line treatment of acute uncomplicated UTI has traditionally involved a 3-day regimen of trimethoprim-sulfamethoxazole (TMP-SMX) or TMP alone for patients with sulfa allergies. Increasing resistance among community-acquired Escherichia coli to TMP-SMX worldwide has led to a reassessment of the most appropriate empiric therapy for these infections. Alternative first-line agents include the fluoroquinolones, nitrofurantoin, and fosfomycin.Factors to be considered in the selection of appropriate antimicrobial therapy include pharmacokinetics, spectrum of activity of the antimicrobial agent, resistance prevalence for the community, potential for adverse effects, and duration of therapy. Ideal antimicrobial agents for UTI management have primary excretion routes through the urinary tract to achieve high urinary drug levels. In addition, there are special considerations in the management of UTI among selected populations, including postmenopausal and pregnant women, and for women with frequent recurrent UTIs.     

Antimicrobial Susceptibility Pattern and Epidemiology of Female Urinary Tract Infections in South Korea, 2010-2011

This study aimed to (i) investigate the antimicrobial susceptibilities of bacteria that cause urinary tract infections (UTIs) in outpatient and inpatient settings and (ii) evaluate the risk factors for emerging antimicrobial drug resistance in UTIs in South Korea. In total, 3,023 samples without duplication were collected from females between 25 and 65 years of age who had been diagnosed with a urinary tract infection. Multicenter patient data were collected using a Web-based electronic system and then evaluated. The isolation rates of Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecium in the outpatient setting were 78.1, 4.7, and 1.3%, respectively; in the inpatient setting, the isolation rates of these microorganisms were 37.8, 9.9, and 14.8%, respectively. The susceptibilities of E. coli to amikacin, amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, piperacillin-tazobactam, and imipenem in the outpatient setting were 99.4, 79.8, 89.4, 92.8, 69.8, 96.9, and 100.0%, respectively; in the inpatient setting, the susceptibilities to these antibiotics were 97.8, 73.9, 73.7, 82.1, 53.6, 93.2, and 100.0%, respectively. The most unique and common risk factor for emerging antimicrobial-resistant E. coli, K. pneumoniae, and E. faecium was previous exposure to antimicrobials. On the basis of these data, the use of fluoroquinolones should be reserved until culture data are available for the treatment of UTIs in South Korea. The present study will serve as a useful reference for Far Eastern Asia.     

The ECO.SENS Project: a prospective, multinational, multicentre epidemiological survey of the prevalence and antimicrobial susceptibility of urinary tract pathogens--interim report

The ECO.SENS Project is the first international survey to investigate the prevalence and susceptibility of pathogens causing community-acquired, uncomplicated urinary tract infections (UTIs) in women. At 240 centres in 17 countries, female patients presenting with symptoms of uncomplicated UTIs were asked to provide a urine sample for testing for the presence of leucocytes and bacteria. The bacteria were identified and their susceptibility to 12 antibiotics commonly used in the treatment of UTIs was determined. The objective of the survey was to collect 5000 urine samples to obtain approximately 3500 isolates of defined uropathogens. This interim report includes the results from 1960 urine samples, 75% of which contained a uropathogen. Escherichia coli accounted for the majority (80%) of uropathogens isolated in all 17 countries. The rates of resistance among E. coli strains were: ampicillin and sulphamethoxazole, 30%; trimethoprim alone or with sulphamethoxazole, 15%; nalidixic acid, 6%; ciprofloxacin, 3%; amoxycillin-clavulanic acid, mecillinam, cefadroxil, nitrofurantoin and fosfomycin, < or =2%. The use of ampicillin, sulphonamides and trimethoprim alone or with sulphamethoxazole needs to be reconsidered. The seemingly rapid increase in quinolone resistance among community-acquired E. coli in some of the countries gives cause for concern.     

Evaluation of Antimicrobial Susceptibility of Enterobacteriaceae Causing Urinary Tract Infections in Africa

Our objective was to evaluate the antimicrobial susceptibility of Enterobacteriaceae causing urinary tract infections (UTIs) in adults in Africa. The PubMed database was systematically searched to identify relevant studies published after 2000. Google, World Health Organization, and African Field Epidemiology networks were also searched. Twenty-eight studies, accounting for 381,899 urine isolates from 14 African countries, met the inclusion criteria. Escherichia coli, Klebsiella spp., and Proteus spp. were the most commonly encountered uropathogens. Cefotaxime, imipenem, fosfomycin, and ciprofloxacin were the antibiotics with the highest activity against E. coli isolates from outpatients, with susceptibility being 92 to 99, 100, 100, and 68 to 91%, respectively. The susceptibility among Klebsiella spp. isolates from outpatients varied from 80 to 100% for amikacin and from 53 to 100% for ciprofloxacin, while susceptibility was 74 to 78, 97, and 77% for ciprofloxacin, amikacin, and fosfomycin, respectively, among Klebsiella species isolates from inpatients or patients with hospital-acquired UTIs. With regard to Proteus spp., the highest activity was observed among fluoroquinolones; 71 to 100% of the P. mirabilis isolates were susceptible to ciprofloxacin in four studies, and 74 to 100% of the P. vulgaris isolates were susceptible to ofloxacin in two studies. The currently available evidence suggests that the antimicrobial susceptibility patterns of Enterobacteriaceae uropathogens in African countries were similar to those in countries of southeast Europe. Further original studies are warranted from African countries for which there is limited published data.     

Addressing antibiotic resistance

Management of uncomplicated urinary tract infections (UTIs) has traditionally been based on 2 important principles: the spectrum of organisms causing acute UTI is highly predictable (Escherichia coli accounts for 75% to 90% and Staphylococcus saprophyticus accounts for 5% to 15% of isolates), and the susceptibility patterns of these organisms have also been relatively predictable. As a result, empiric therapy with short-course trimethoprim-sulfamethoxazole (TMP-SMX) has been a standard management approach for uncomplicated cystitis.However, antibiotic resistance is now becoming a major factor not only in nosocomial complicated UTIs, but also in uncomplicated community-acquired UTIs. Resistance to TMP-SMX now approaches 18% to 22% in some regions of the United States, and nearly 1 in 3 bacterial strains causing cystitis or pyelonephritis demonstrate resistance to amoxicillin. Fortunately, resistance to other agents, such as nitrofurantoin and the fluoroquinolones, has remained low, at approximately 2%. Preliminary data suggest that the increase in TMP-SMX resistance is associated with poorer bacteriologic and clinical outcomes when TMP-SMX is used for therapy. As a result, these trends have necessitated a change in the management approach to community-acquired UTI. The use of TMP-SMX as a first-line agent for empiric therapy of uncomplicated cystitis is only appropriate in areas where TMP-SMX resistance prevalence is <10% to 20%. In areas where resistance to TMP-SMX exceeds this rate, alternative agents need to be considered.     

The etiology of urinary tract infection: traditional and emerging pathogens

The microbial etiology of urinary infections has been regarded as well established and reasonably consistent. Escherichia coli remains the predominant uropathogen (80%) isolated in acute community-acquired uncomplicated infections, followed by Staphylococcus saprophyticus (10% to 15%). Klebsiella, Enterobacter, and Proteus species, and enterococci infrequently cause uncomplicated cystitis and pyelonephritis.The pathogens traditionally associated with UTI are changing many of their features, particularly because of antimicrobial resistance. The etiology of UTI is also affected by underlying host factors that complicate UTI, such as age, diabetes, spinal cord injury, or catheterization. Consequently, complicated UTI has a more diverse etiology than uncomplicated UTI, and organisms that rarely cause disease in healthy patients can cause significant disease in hosts with anatomic, metabolic, or immunologic underlying disease. The majority of community-acquired symptomatic UTIs in elderly women are caused by E coli. However, gram-positive organisms are common, and polymicrobial infections account for up to 1 in 3 infections in the elderly. In comparison, the most common organisms isolated in children with uncomplicated UTI are Enterobacteriaceae. Etiologic pathogens associated with UTI among patients with diabetes include Klebsiella spp., Group B streptococci, and Enterococcus spp., as well as E coli. Patients with spinal cord injuries commonly have E coli infections. Other common uropathogens include Pseudomonas and Proteus mirabilis.Recent advances in molecular biology may facilitate the identification of new etiologic agents for UTI. The need for accurate and updated population surveillance data is apparent, particularly in light of concerns regarding antimicrobial resistance. This information will directly affect selection of empiric therapy for UTI.     

A randomized comparative study of single-dose fosfomycin and 5-day ciprofloxacin in female patients with uncomplicated lower urinary tract infections

Uncomplicated lower urinary tract infections (UTIs) are the most frequent infections in females. Increased resistance rates against commonly used antibiotics have led to the use of novel antimicrobials. The aim of the present study was to evaluate the bacteriological and clinical effects of single-dose fosfomycin trometamol (FMT) and 5-day ciprofloxacin in females with uncomplicated UTIs. In this randomized comparative study, 260 female patients between 18 and 65 years of age enrolled, of whom 142 completed the study. The most frequently isolated bacterial pathogen in the urine cultures of patients were Escherichia coli (82.3%) and Enterobacter spp. (8.4%). FMT sensitivity was 94% and ciprofloxacin sensitivity was 59% in Escherichia coli; in comparison, FMT sensitivity was 75% and ciprofloxacin sensitivity was 50% in Enterobacter spp. The MIC90 for FMT was 4 μg/ml. Of the 142 patients, 77 were treated with FMT and 65 were treated with ciprofloxacin. The clinical remission rate was 83% in the FMT group and 81% in the ciprofloxacin group; the bacterial eradication rate was 83% in the FMT group and 78% in the ciprofloxacin group, and there was no significant difference between the two study groups. In conclusion, a single dose of FMT (at 3 g) was as effective as ciprofloxacin, at 500 mg twice a day for 5 days, in the treatment of uncomplicated lower UTIs. It was concluded that the use of FMT as a first-line treatment in the empirical treatment of uncomplicated UTIs might have a positive impact on the problem of resistance to other antibiotics.     

Resistance of uropathogenic bacteria to first-line antibiotics in mexico city: A multicenter susceptibility analysis

Abstract

Background

Growing antibiotic resistance demands the constant reassessment of antimicrobial efficacy, particularly in countries with wide antibiotic abuse, where higher resistance prevalence is often found. Knowledge of resistance trends is particularly important when prescribing antibiotics empirically, as is usually the case for urinary tract infections (UTIs). Currently, in Mexico City, ampicillin, cotrimoxazole (trimethoprim/sulfamethoxazole), and ciprofloxacin are used as “first-line” antibiotic treatment for UTI.

Objective

The aim of this study was to analyze the resistance of bacterial isolates to antibiotics, with a focus on first-line antibiotics, in Mexican pediatric patients and sexually active or pregnant female outpatients.

Methods

In this multicenter susceptibility analysis, bacterial isolates from urine samples collected from pediatric patients and sexually-active or pregnant female outpatients presenting with acute, uncomplicated UTIs in Mexico City from January 2006 through June 2006, were included in the study. Samples were tested for susceptibility to 10 antibiotics by the disk-diffusion method.

Results

Four-hundred and seventeen bacterial isolates were derived from sexually active or pregnant female outpatients (324 Escherichia coli) and pediatric patients (93 Klebsiella pneumoniae). We found a high prevalence of resistance towards the drugs used as “first-line” when treating UTIs: ampicillin, cotrimoxazole, and ciprofloxacin (79%, 60%, and 24% resistance, respectively). Ninety-eight percent of K pneumoniae isolates were resistant to ampicillin, whereas 66% of the E coli isolates were resistant to cotrimoxazole. Resistance towards third-generation cephalosporins was also high (6%–8% of E coli and 10%–28% of K pneumoniae). This was possibly caused by chromosomal β-lactamases, as 30% of all isolates were also resistant to amoxicillin/clavulanate. In contrast, 98% of the E coli isolates and 84% of the K pneumoniae strains (96% of all isolates) were found to be susceptible to nitrofurantoin, which has been in clinical use for much longer than most other drugs in this study.

Conclusion

In these urine samples from laboratories in Mexico City, resistance of K pneumoniae and E coli isolates to first-line treatment (ampicillin, cotrimoxazole, or ciprofloxacin) of UTI was high, whereas most E coli and K pneumoniae isolates were susceptible to nitrofurantoin and the fourth-generation cephalosporin cefepime. (Curr Ther Res Clin Exp. 2007;68:120–126) Copyright © 2007 Excerpta Medica, Inc.Key Words: urinary tract infection, uropathogenic bacteria     

The expanding role of fluoroquinolones

There has been a growing rate of resistance among common urinary tract pathogens, such as Escherichia coli, to traditional antimicrobial therapies including the "gold standard" trimethoprim-sulfamethoxazole (TMP-SMX). Consequently, fluoroquinolone antimicrobial agents have taken on an expanding management role for UTIs. In fact, the recent Infectious Diseases Society of America clinical management guidelines for UTI recommend fluoroquinolones as first-line therapy for uncomplicated UTI in areas where resistance is likely to be of concern. Fluoroquinolones have demonstrated high bacteriologic and clinical cure rates, as well as low rates of resistance, among most common uropathogens. There are currently 7 fluoroquinolones with indications for UTI in the United States. However, only 3 are commonly used: levofloxacin, ciprofloxacin, and, to a lesser extent, gatifloxacin. Many of the fluoroquinolone agents have once-daily dosing regimens, enhancing patient adherence. In addition, levofloxacin and gatifloxacin have same-dose bioequivalency between their intravenous and oral formulations, allowing for "switch" or step-down therapy from parenteral to oral formulations of the same agent at the same dose.Fluoroquinolones are indicated for the management of acute uncomplicated UTIs, as well as complicated and severe UTI and pyelonephritis, in adults. They are the first-line treatment of acute uncomplicated cystitis in patients who cannot tolerate sulfonamides or TMP, who live in geographic areas with known resistance >10% to 20% to TMP-SMX, or who have risk factors for such resistance. Fluoroquinolone properties include a broad spectrum of coverage, low rates of resistance, and good safety profiles.     

Diagnosis and management of urinary tract infection and pyelonephritis

Urinary tract infections (UTIs) are the most common bacterial infections treated in the outpatient setting and range in severity from minimally symptomatic cystitis to severe septic shock in a wide array of patients. Diagnosis of uncomplicated cystitis can be inferred from history and physical, and confirmed by urinalysis. Appropriate antimicrobial therapy should rapidly improve symptoms in all UTIs. Treatment can be further tailored according to severity of illness, analysis of individualized risk factors, and antimicrobial resistance patterns. This article discusses treatment options in light of bacterial resistance in the twenty-first century.     

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.     

Risk factors for ciprofloxacin resistance among Escherichia coli strains isolated from community-acquired urinary tract infections in Turkey

OBJECTIVES: To determine the risk factors for community-acquired ciprofloxacin-resistant Escherichia coli urinary tract infection (UTI). METHODS: The study was performed with isolates from community-acquired UTIs collected from 15 centres representing six different geographic regions of Turkey. All microbiological procedures were carried out in a central laboratory. Multivariate analysis was performed for detection of risk factors for resistance. Use of quinolones more than once within the last year, living in a rural area, having a urinary catheter, age >50 and complicated infections were included in the model as variables and logistic regression was performed. RESULTS: A total of 611 gram-negative isolates were studied: 321 were isolated from uncomplicated UTI and 290 were isolated from complicated UTI. E. coli was the causative agent in 90% of the uncomplicated UTIs and in 78% of the complicated UTIs (P < 0.001). Seventeen percent of E. coli strains isolated from uncomplicated cases and 38% of E. coli strains isolated from complicated UTI were found to be resistant to ciprofloxacin. In multivariate analysis, age over 50 [odds ratio (OR): 1.6; confidence interval (CI): 1.08-2.47; P = 0.020], ciprofloxacin use more than once in the last year (OR: 2.8; CI: 1.38-5.47; P = 0.004) and the presence of complicated UTI (OR: 2.4; CI: 1.54-3.61; P < 0.001) were found to be associated with ciprofloxacin resistance. Detection of strains of E. coli producing extended-spectrum beta-lactamase (ESBL) enzymes was two times more common in the patients who received ciprofloxacin than those who did not (15% versus 7.4%). CONCLUSIONS: The increasing prevalence of infections caused by antibiotic-resistant bacteria makes the empirical treatment of UTIs more difficult. One of the important factors contributing to these high resistance rates might be high antibiotic use. Urine culture and antimicrobial susceptibility testing are essential in Turkey for patients with UTI who have risk factors for resistance, such as previous ciprofloxacin use. Fluoroquinolone-sparing agents such as nitrofurantoin and fosfomycin should be evaluated as alternative therapies by further clinical efficacy and safety studies.     

Second nationwide surveillance of bacterial pathogens in patients with acute uncomplicated cystitis conducted by Japanese Surveillance Committee from 2015 to 2016: antimicrobial susceptibility of Escherichia coli,Klebsiella pneumoniae,and Staphylococcus saprophyticus

The Japanese Surveillance Committee conducted a second nationwide surveillance of antimicrobial susceptibility patterns of uropathogens responsible for acute uncomplicated cystitis (AUC) in premenopausal patients aged 16–40 years old at 31 hospitals throughout Japan from March 2015 to February 2016. In this study, the susceptibility of causative bacteria (Escherichia coli, Klebsiella pneumoniae, Staphylococcus saprophyticus) for various antimicrobial agents was investigated by isolation and culturing of organisms obtained from urine samples. In total, 324 strains were isolated from 361 patients, including E. coli (n = 220, 67.9%), S. saprophyticus (n = 36, 11.1%), and K. pneumoniae (n = 7, 2.2%). The minimum inhibitory concentrations (MICs) of 20 antibacterial agents for these strains were determined according to the Clinical and Laboratory Standards Institute (CLSI) manual. At least 93% of the E. coli isolates showed susceptibility to fluoroquinolones and cephalosporins, whereas 100% of the S. saprophyticus isolates showed susceptibility to fluoroquinolones and aminoglycosides. The proportions of fluoroquinolone-resistant and extended-spectrum β-lactamase (ESBL)-producing E. coli strains were 6.4% (13/220) and 4.1% (9/220), respectively. The antimicrobial susceptibility of K. pneumoniae was retained during the surveillance period, while no multidrug-resistant strains were identified.In summary, antimicrobial susceptibility results of our second nationwide surveillance did not differ significantly from those of the first surveillance. Especially the numbers of fluoroquinolone-resistant and ESBL-producing E. coli strains were not increased in premenopausal patients with AUC in Japan.     

Urinary tract infections in the elderly population

Background

Urinary tract infections (UTIs) are a common problem in the elderly population. The spectrum of disease varies from a relatively benign cystitis to potentially life-threatening pyelonephritis.

Objective

This review covers the management of asymptomatic bacteriuria, acute uncomplicated cystitis, acute uncomplicated pyelonephritis, antibiotic resistance, catheter-associated bacteriuria/symptomatic UTIs, and antibiotic prophylaxis for recurrent infections in elderly men and women.

Methods

Literature was obtained from English-language searches of MEDLINE (1966–April 2011), Cochrane Library, BIOSIS (1993–April 2011), and EMBASE (1970–April 2011). Further publications were identified from citations of resulting articles. Search terms included, but were not limited to, urinary tract infections, asymptomatic bacteriuria, acute uncomplicated cystitis, acute uncomplicated pyelonephritis, antibiotic resistance, catheter associated urinary tract infections, recurrent urinary tract infections, and elderly.

Results

The prevalence of UTIs in elderly women depends on the location in which these women are living. For elderly women living in the community, UTIs compromise the second most common infection, whereas in residents of long-term care facilities (LTCFs) and hospitalized subjects, it is the number one cause of infection. The spectrum of patient presentation varies from classic signs and symptoms in the independent elderly population to atypical presentations, including increased lethargy, delirium, blunted fever response, and anorexia. Although there are few guidelines specifically directed toward the management of UTIs in the elderly population, therapy generally mirrors the recommendations for the younger adult age groups. When choosing a treatment regimen, special attention must be given to the severity of illness, living conditions, existing comorbidities, presence of external devices, local antibiotic resistance patterns, and the ability of the patient to comply with therapy.

Conclusions

Improved guidelines for the diagnosis and management of UTIs in the elderly population are needed. Better techniques to evaluate and prevent catheter-associated bacteriuria and UTIs await improved diagnostic modalities and catheter technologies. Alternative methods for prophylaxis of patients who suffer from recurrent infections must be found while minimizing the risk of developing or propagating antibiotic resistance.     

Antibiotic resistance in isolates recovered from women with community-acquired urinary tract infections presenting to a tertiary care emergency department

ABSTRACTIntroduction:We sought to determine the antibiotic susceptibility of organisms causing community-acquired urinary tract infections (UTIs) in adult females attending an urban emergency department (ED) and to identify risk factors for antibiotic resistance.Methods:We reviewed the ED charts of all nonpregnant, nonlactating adult females with positive urine cultures for 2008 and recorded demographics, diagnosis, complicating factors, organism susceptibility, and risk factors for antibiotic resistance. Odds ratios (ORs) and 95% confidence intervals (CIs) for potential risk factors were calculated.Results: Our final sample comprised 327 UTIs: 218 were cystitis, of which 22 were complicated cases and 109 were pyelonephritis, including 22 complicated cases. Escherichia coli accounted for 82.3% of all UTIs, whereas Staphylococcus saprophyticus accounted for 5.2%. In uncomplicated cystitis, 9.5% of all isolates were resistant to ciprofloxacin and 24.0% to trimethoprim-sulfamethoxazole (TMP-SMX). In uncomplicated pyelonephritis, 19.5% of isolates were resistant to ciprofloxacin and 36.8% to TMP-SMX. In UTI (all types combined), any antibiotic use within the previous 3 months was a significant risk factor for resistance to both ciprofloxacin (OR 3.34, 95% CI 1.16-9.62) and TMP-SMX (OR 4.02, 95% CI 1.48-10.92). Being 65 years of age or older and having had a history of UTI in the previous year were risk factors only for ciprofloxacin resistance. Conclusions:E. coli was the predominant urinary pathogen in this series. Resistance to ciprofloxacin and TMP-SMX was high, highlighting the importance of relevant, local antibiograms. Any recent antibiotic use was a risk factor for both ciprofloxacin and TMP-SMX resistance in UTI. Our findings should be confirmed with a larger prospective study.