Reliability of a single urine culture in establishing diagnosis of asymptomatic bacteriuria in adult males

European Association of Urology Guidelines on Urological Infections: Summary of the 2024 Guidelines

BACKGROUND AND OBJECTIVE

Urological infections significantly impact the wellbeing and quality of life of individuals owing to their widespread occurrence and diverse clinical manifestations. The objective of the guidelines panel was to provide evidence-based guidance on the diagnosis, treatment, and prevention of urinary tract infections (UTIs) and male accessory-gland infections, while addressing crucial public health aspects related to infection control and antimicrobial stewardship.

METHODS

For the 2024 guidelines on urological infections, new and relevant evidence was identified, collated, and appraised via a structured assessment of the literature. Databases searched included Medline, EMBASE, and the Cochrane Libraries. Recommendations within the guidelines were developed by the panel to prioritise clinically important care decisions. The strength of each recommendation was determined according to a balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including the certainty of estimates), and the nature and variability of patient values and preferences.

KEY FINDINGS AND LIMITATIONS

Key recommendations emphasise the importance of a thorough medical history and physical examination for patients with urological infections. The guidelines stress the role of antimicrobial stewardship to combat the rising threat of antimicrobial resistance, providing recommendations for antibiotic selection, dosing, and duration on the basis of the latest evidence.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This overview of the 2024 EAU guidelines offers valuable insights into managing urological infections and are designed for effective integration into clinical practice.

PATIENT SUMMARY

The European Association of Urology has issued an updated guideline on urological infections. The guidelines provide recommendations for diagnosis, treatment, and prevention, with a particular focus on minimising antibiotic use because of the increasing global threat of antimicrobial resistance.

Urinary calprotectin as a diagnostic tool for detecting significant bacteriuria

Pyuria in dipstick examination serves as the most widespread screening tool for urinary tract infections (UTI). The absence of pyuria, however, does not exclude UTI. We investigated the diagnostic value of urinary calprotectin, a mediator protein of the innate immune system, which is released by leukocytes, for the detection of UTI and compared it with dipstick pyuria. Since even low numbers of leukocytes in the urine significantly increase urinary calprotectin concentrations, calprotectin might be a more sensitive marker than pyuria detected by dipstick. All 162 patients were prospectively included and underwent a urine dipstick, urine culture, quantification of proteinuria and determination of calprotectin in the urine. Urinary calprotectin was determined using an enzyme-linked immunosorbent assay (ELISA). UTI was defined as urine cultures with detection of one or a maximum of two uropathogenic bacteria with ≥ 105 colony-forming units per millilitre (CFU/ml). Exclusion criteria were acute kidney injury, chronic renal insufficiency and tumors of the urinary tract. 71 (43.8%) patients had a UTI. Of the 91 patients without UTI, 23 had a contamination and 19 had evidence of ≥ 105 CFU/ml considered to be asymptomatic bacteriuria. The median calprotectin concentration in patients with UTI and pyuria was significantly higher than in patients with UTI and without pyuria (5510.4 vs. 544.7 ng/ml). In ROC analyses, calprotectin revealed an area under the curve (AUC) of 0.70 for the detection of significant bacteriuria. Pyuria in dipstick examinations provided an AUC of 0.71. There was no significant difference between these AUCs in the DeLong test (p = 0.9). In patients with evidence of significant bacteriuria but without pyuria, a significantly higher calprotectin concentration was measured in the urine than in patients with neither pyuria nor UTI (544.7 ng/ml vs 95.6 ng/ml, p = 0.029). Urinary calprotectin is non-inferior to dipstick pyuria in the detection of UTI.

Asymptomatic Bacteriuria in Kidney Transplant Recipients-A Narrative Review

Urinary tract infections (UTIs) are the most prevalent complications in kidney transplant (KTx) recipients. The most frequent finding in this group of patients is asymptomatic bacteriuria (ASB). Here, we provide an overview of the available evidence regarding ASB in KTx recipients, including its etiopathology, clinical impact and management. There is a growing body of evidence from clinical trials that screening for and treating ASB is not beneficial in most KTx recipients. However, there are insufficient data to recommend or discourage the use of a "screen-and-treat strategy" for ASB during the first 1-2 months post-transplant or in the case of an indwelling urinary catheter. Despite its frequency, ASB after KTx is still an understudied phenomenon.

The efficacy of a suppository based on Phenolmicin P3 and Bosexil (Mictalase®) in control of irritative symptoms in patients undergoing thulium laser enucleation of prostate: a single-center, randomized, controlled, open label, phase III study

BACKGROUND

Several studies described post-operative irritative symptoms after laser enucleation of prostate, sometimes associated with urge incontinence, probably linked to laser-induced prostatic capsule irritation, and potential for lower urinary tract infections We aimed to evaluate the efficacy of a suppository based on Phenolmicin P3 and Bosexil (Mictalase®) in control of irritative symptoms in patients undergoing thulium laser enucleation of prostate (ThuLEP).

METHODS

In this single-center, prospective, randomized, open label, phase-III study, patients with indication to ThuLEP were enrolled (Dec2019-Feb2021-Institutional ethics committee STS CE Lazio approval no.1/N-726-ClinicalTrials.gov NCT05130918). The report conformed to CONSORT 2010 guidelines. Eligible patients were 1:1 randomized. Randomization defined Group A: patients who were administered Mictalase® suppositories twice a day for 5 days, then once a day for other 10 days; Group B: patients who did not receive Mictalase® ("controls"). Study endpoints were evaluated at 15 and 30 days postoperation. Primary endpoint included evaluation of effects of the suppository on irritative symptoms by administering IPSS + QoL questionnaire. Secondary endpoint included evaluation of effects on urinary tract infections by performance of urinalysis with urine culture.

RESULTS

111 patients were randomized: 56 in Group A received Mictalase®. Baseline and perioperative data were comparable. At 15-days, no significant differences were found in terms of IPSS + QoL scores and urinalysis parameters. A significant difference in the rate of positive urine cultures favored Group A (p = 0.04). At 30-days follow-up, significant differences were found in median IPSS score (6 [IQR 3-11] versus 10 [5-13], Group A vs B, respectively, p = 0.02). Urinalysis parameters and rate of positive urine cultures were not significantly different.

CONCLUSIONS

The present randomized trial investigated the efficacy of Mictalase® in control of irritative symptoms and prevention of lower urinary tract infections in patients undergoing ThuLEP. IPSS improvement 30-days postoperation was more pronounced in patients who received Mictalase®. Lower rate of positive urine culture favored Mictalase® group 15-days postoperatively.

TRIAL REGISTRATION

The clinical trial has been registered on ClinicalTrials.gov on November 23rd, 2021-Registration number NCT05130918.

Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America

Asymptomatic bacteriuria (ASB) is a common finding in many populations, including healthy women and persons with underlying urologic abnormalities. The 2005 guideline from the Infectious Diseases Society of America recommended that ASB should be screened for and treated only in pregnant women or in an individual prior to undergoing invasive urologic procedures. Treatment was not recommended for healthy women; older women or men; or persons with diabetes, indwelling catheters, or spinal cord injury. The guideline did not address children and some adult populations, including patients with neutropenia, solid organ transplants, and nonurologic surgery. In the years since the publication of the guideline, further information relevant to ASB has become available. In addition, antimicrobial treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance. The current guideline updates the recommendations of the 2005 guideline, includes new recommendations for populations not previously addressed, and, where relevant, addresses the interpretation of nonlocalizing clinical symptoms in populations with a high prevalence of ASB.

Research progress of asymptomatic bacteriuria before arthroplasty: A systematic review

BACKGROUND

A high prevalence of asymptomatic bacteriuria exists in patients prior to arthroplasty, and urinary tract infection is considered to be a source of postoperative superficial wound and prosthetic joint infections. There is no consensus whether to screen for and treat asymptomatic bacteriuria before arthroplasty.

OBJECTIVE

To summarize the association between asymptomatic bacteriuria and complications after arthroplasty and to evaluate the clinical benefits of treating asymptomatic bacteriuria prior to arthroplasty.

METHOD

We systematically searched PubMed, Embase, and the Cochrane Library to retrieve potentially eligible articles. By screening the titles and abstracts of retrieved records and then reading the full texts of the remaining papers, we finally included 8 English-language articles in this systematic review.

RESULTS

Asymptomatic bacteriuria prior to arthroplasty is significantly associated with an increased occurrence of postoperative prosthetic joint and superficial wound infections. However, there is little evidence for direct or hematogenous seeding of urinary infections, and treating asymptomatic bacteriuria before arthroplasty did not decrease the incidence of postoperative infectious complications.

CONCLUSION

Asymptomatic bacteriuria is not a contraindication for arthroplasty, and the practice of routine preoperative screening for and treatment of asymptomatic bacteriuria should not be continued.

Asymptomatic Bacteriuria and Bacterial Interference

Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from <1% in newborns to 10% to 20% of women age 80 years, but is uncommon in men until after age 50 years. Individuals with underlying genitourinary abnormalities, including indwelling devices, may also have a high frequency of asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients.

Are antibiotics necessary in hip arthroplasty with asymptomatic bacteriuria? Seeding risk with/without treatment

BACKGROUND

In patients with asymptomatic bacteriuria undergoing hip arthroplasty, the risk of prosthetic joint infection (PJI) and appropriateness of specific antibiotics are unclear.

QUESTIONS/PURPOSES

We determined (1) the prevalence of asymptomatic bacteriuria; and (2) the incidence of PJI in patients with asymptomatic bacteriuria managed with or without specific antibiotics.

METHODS

We conducted a prospective, randomized study of all 471 patients without urinary symptoms receiving a total hip arthroplasty (THA; n = 228; average age 68 years; 122 female) or hemiarthroplasty (HA; n = 243; average age 85 years; 170 female) between April 2009 and November 2010. No patients were catheterized in the perioperative period and all received intravenous cefazolin (allergy, vancomycin) for 48 hours postoperatively. Urinalysis was conducted on all patients; if abnormal, a urine culture was performed. Patients with bacteriuria (> 100,000 colonies/mL cultured) were randomly assigned to receive specific antibiotics (Group A) or not (Group B). Minimum followup was 1 month including those six who died or were lost to followup (average, 10.4 months; range, 1-12 months).

RESULTS

Asymptomatic bacteriuria occurred in eight of 228 patients undergoing THAs (three of eight with specific antibiotics) and 38 of 243 patients undergoing HAs (23 of 38 with specific antibiotics). Arthroplasty infection after 3 months occurred in one of 228 patients undergoing THAs and 12 of 243 patients undergoing HAs (six of 117 in Group A and six of 126 in Group B); bacteria cultured from the wound were dissimilar to those cultured in urine samples in any case. No patient presented signs of PJI by 1 year after the index surgery.

CONCLUSIONS

We identified no case of PJI from urinary origin in patients with asymptomatic bacteriuria whether or not they had been treated with specific antibiotics.

Asymptomatic bacteriuria in the elderly: high prevalence and high turnover of strains

Asymptomatic bacteriuria (ASB) was followed in repeated prevalence surveys in a cohort of non-institutionalized residents (n=330), aged>or=80 y. Urine samples were collected at baseline, and at 6, and at 18 months. Phenotyping (PhenePlate) was performed on isolates of Escherichia coli to evaluate strain relatedness. ASB occurred in 19.0, 19.4, and 19.9% in women, and in 9.4, 9.6 and 7.9% in men, at baseline and at the 6- and 18-months follow-up, respectively, and ASB was found at least once in 37% of women and in 20% of men. Of those with ASB at baseline, 60% also had ASB in the 2 subsequent surveys. Among those with persisting E. coli bacteriuria, 76% and 40%, respectively, carried the same strain at the 6- and 18-months follow-ups. In women, we found that the risk of developing a symptomatic urinary tract infection within 24 months was higher among those with ASB at baseline than in those without bacteriuria (p=0.019). ASB is common and often persistent, but we found a high turnover of strains, indicating a high rate of recolonization.

Asymptomatic bacteriuria: review and discussion of the IDSA guidelines

Asymptomatic bacteriuria is a common finding, but is usually benign. Screening and treatment of asymptomatic bacteriuria is only recommended for pregnant women, or for patients prior to selected invasive genitourinary procedures. Healthy women identified with asymptomatic bacteriuria on population screening subsequently experience more frequent episodes of symptomatic infection, but antimicrobial treatment of asymptomatic bacteriuria does not decrease the occurrence of these episodes. Clinical trials in spinal-cord injury patients, diabetic women, patients with indwelling urethral catheters, and elderly nursing home residents have consistently found no benefits with treatment of asymptomatic bacteriuria. Negative outcomes with antimicrobial treatment do occur, including adverse drug effects and re-infection with organisms of increasing resistance. Optimal management of asymptomatic bacteriuria requires appropriate implementation of screening strategies to promote timely identification of the selected patients for whom treatment is beneficial, and avoidance of antimicrobial therapy where no benefit has been shown.

Asymptomatic bacteriuria: when to screen and when to treat

Asymptomatic bacteriuria is common. Populations with structural or functional abnormalities of the genitourinary tract may have an exceedingly high prevalence of bacteriuria, but even healthy individuals frequently have positive urine cultures. Asymptomatic bacteriuria is seldom associated with adverse outcomes. Pregnant women and individuals who are to undergo traumatic genitourinary interventions are at risk for complications of bacteriuria and benefit from screening and treatment programs. Although screening is recommended for renal transplant recipients, the benefits for these patients are less clear. For other populations, including most bacteriuric individuals, negative outcomes attributable to asymptomatic bacteriuria have not been described. Treatment of asymptomatic bacteriuria in these patients is not beneficial and, in fact, may be associated with harmful outcomes, such as increased short-term frequency of symptomatic infection, adverse drug effects, and reinfection with organisms of increased antimicrobial resistance. Screening for asymptomatic bacteriuria and treatment is recommended for only selected groups where benefit has been shown. Many research questions still need to be addressed. Different populations have unique risk factors, and the benefits and risks of different management approaches for asymptomatic bacteriuria must continue to be addressed systematically in appropriate clinical trials.

Urinary tract infection in men with AIDS

OBJECTIVE--To investigate whether bacteriuria and, specifically, symptomatic urinary tract infection (UTI) occur with increased frequency in men with HIV infection. METHODS--In this cross-sectional study we investigated three groups of men, aged from 18 to 50 years. Group A was composed of patients with a diagnosis of AIDS; Group B, of patients without HIV infection, and group C of patients with asymptomatic HIV infection. Patients with any known predisposing factor for UTI were excluded from the study. A clean-catch midstream urine sample was collected from each patient on the first day of hospital admission (groups A and B) or during a visit to the outpatient clinic (group C). Bacteriuria was diagnosed when > or = 100,000 colony forming units/ml, urine were grown. RESULTS--There were 415 patients, 151 in group A, 170 in group B and 94 in group C. Bacteriuria was significantly more frequently in group A (20 cases, 13.3%) than in groups B (3 cases, 1.8%, p = 0.00007) and C (3 cases, 3.2%, p = 0.009). Ten cases of bacteriuria in group A (6.6%) were symptomatic while no case of symptomatic UTI was seen in groups B (p = 0.0004) and C (p = 0.008). The frequency of UTI in homosexual men with AIDS (7 cases, 6.7%) was not significantly different from that observed in men with AIDS who denied homosexuality (3 cases, 6.5%). E coli was the predominant pathogen associated with UTI. Although adequate response to a two-week course of antibiotics was observed in most cases, an in-hospital mortality rate of 20% was found among AIDS patients with symptomatic UTI. CONCLUSIONS--In the present study, the frequency of bacteriuria and symptomatic UTI was found to be increased in men with AIDS. E coli was the predominant pathogen in these cases. These data suggest that symptomatic UTI may represent a relevant cause of morbidity for men with AIDS.

Clinically inapparent (asymptomatic) bacteriuria in ambulatory elderly men: epidemiological, clinical, and microbiological findings

In a prospective longitudinal study, ambulatory elderly men were followed from 1 to 4.5 years to gain insight into the prevalence rates, clinical characteristics, and patterns of clinically inapparent (asymptomatic) bacteriuria (CIB). The prevalence of CIB was 12% (29/238) and increases with age. Unlike the gram-negative organisms that cause overt urinary tract infection in this age group, gram-positive organisms dominated the CIB group. Both the CIB and abacteriuric patients have multiple chronic medical conditions and are indistinguishable on that basis. Twenty-nine elderly men with bacteriuria and 105 abacteriuric subjects were followed with serial urine cultures. During the study period the bacteriuric subjects exhibited spontaneous temporary or permanent resolution (76%, 22/29), intermittency (21%, 6/29), and probable bacterial persistence (38%, 11/29). No consistent pattern of bacteriuria was evident. Therefore, antimicrobial therapy is not warranted in the treatment of asymptomatic or clinically inapparent bacteriuria in ambulatory elderly men.

Is the clean-catch midstream void procedure necessary for obtaining urine culture specimens from men?

To determine whether the results of voided urine cultures in men are affected by meatal cleansing, midstream sampling, or circumcision status, 308 paired (initial and midstream) specimens were collected from 254 urology clinic patients. Half of the patients cleansed their urethral meatus with povidone-iodine prior to voiding. The circumcision status of all patients was noted. The rates of true bacteriuria (growth of 10(4) or greater colony-forming units/ml urine with a single predominant species) and contamination (growth of 10(3) or greater colony-forming units/ml urine with two or more colonial types) were compared in the various collection technique subgroups. Neither the bacteriuria nor contamination rates were significantly different (p greater than 0.05) in circumcised and uncircumcised patients, or in those who cleansed their meatus and those who did not. Contamination, but not bacteriuria, rates were higher in initial as compared with midstream specimens. These data suggest that the clean-catch midstream void procedure is unnecessary for obtaining routine voided urine culture specimens from men.

Symptomatic pyelonephritis in elderly men

A prospective study was carried out of the clinical, laboratory, radiologic and therapeutic features of acute, symptomatic, bacterial pyelonephritis as experienced by 12 consecutive elderly, noncatheterized men who required hospitalization. In spite of the advanced ages of the men and the inordinate frequency of bacteremia and septic shock, no patient died. "Appropriate" antibiotic therapy, supportive treatment, and, as importantly, a lack of associated "imminently" or "ultimately" fatal illnesses contributed to the 100 per cent survival rate. Guidelines are provided for the diagnostic evaluation and antibiotic therapy of community-acquired pyelonephritis in elderly men.

Community-acquired bacteremic urosepsis in the elderly patients: a prospective study of 34 consecutive episodes

A prospective study was done on the clinical, laboratory, radiological, immunological and therapeutic features of acute, symptomatic, bacteremic urosepsis in 34 consecutive, elderly patients who required hospitalization. Urinary tract infection was identified as the most common cause of gram-negative bacteremia in elderly patients admitted to a community hospital. Appropriate antibiotic therapy and a lack of serious associated medical illnesses contributed to the high survival rate. Bacteremia and shock occurring in the wake of pyelonephritis develop more commonly in elderly than in young women. In the elderly patient with bacteremia and pyelonephritis radiographic evaluation invariably demonstrates obstruction to urine flow, calculous disease or abscess. Guidelines are provided for the therapy of acute, symptomatic bacteremic urosepsis.

Methods of quantitative microbiological analyses that support the diagnosis, treatment, and prognosis of human infection

The microorganisms responsible for the production of an infection may be considered to be in two classes: classical microbes and host-defined microbes. Classical microbes are those pathogens which fulfill the Koch-Henle postulates, and their isolation from a host indicates infection. They are not normally part of the body's normal flora, although they may be acquired by the host and enter into a passive relationship known as the carrier state. Examples of this type of microbe are Bacillus anthracis (anthrax), Yersinia pestis (plague), and Bordetella pertussis (whooping cough). Pathogens that require specific hosts have largely replaced the classical pathogen as a cause of infection in hospitalized patients. Especially in recent years, with the advent of new modes of anticancer treatment and the general ability of the medical community to extent a patient's life span by chemotherapy and innovative surgery, the contribution to morbidity and mortality by microbes has substantially increased. These host-specific pathogens are largely part of the body's normal flora. It is incumbent upon the clinical microbiologist to be able to distinguish the patient's normal microbial load, an increased load due to physiological factors, but not representing infection, and a significant change from normal which should be considered infection. The ability to distinguish infection from noninfection is one of the prime responsibilities of the clinical microbiology laboratory and has contributed to the development of the infectious disease subspecialty of internal medicine. This article will examine a critical question: Is there a relationship between the numbers of microorganisms isolated from a specimen and the production of infection, and, if so, does this relationship vary for the different anatomical sites of the body?