scholarly journals Strengths and Limitations of Model Systems for the Study of Urinary Tract Infections and Related Pathologies

2016 ◽  
Vol 80 (2) ◽  
pp. 351-367 ◽  
Author(s):  
Amelia E. Barber ◽  
J. Paul Norton ◽  
Travis J. Wiles ◽  
Matthew A. Mulvey

SUMMARYUrinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are a source of substantial morbidity among otherwise healthy women. UTIs can be caused by a variety of microbes, but the predominant etiologic agent of these infections is uropathogenicEscherichia coli(UPEC). An especially troubling feature of UPEC-associated UTIs is their high rate of recurrence. This problem is compounded by the drastic increase in the global incidence of antibiotic-resistant UPEC strains over the past 15 years. The need for more-effective treatments for UTIs is driving research aimed at bettering our understanding of the virulence mechanisms and host-pathogen interactions that occur during the course of these infections. Surrogate models of human infection, including cell culture systems and the use of murine, porcine, avian, teleost (zebrafish), and nematode hosts, are being employed to define host and bacterial factors that modulate the pathogenesis of UTIs. These model systems are revealing how UPEC strains can avoid or overcome host defenses and acquire scarce nutrients while also providing insight into the virulence mechanisms used by UPEC within compromised individuals, such as catheterized patients. Here, we summarize our current understanding of UTI pathogenesis while also giving an overview of the model systems used to study the initiation, persistence, and recurrence of UTIs and life-threatening sequelae like urosepsis. Although we focus on UPEC, the experimental systems described here can also provide valuable insight into the disease processes associated with other bacterial pathogens both within the urinary tract and elsewhere within the host.

2011 ◽  
Vol 60 (4) ◽  
pp. 279-285 ◽  
Author(s):  
BEATA M. ZALEWSKA-PIĄTEK

Urinary tract infections are a very serious health and economic problem affecting millions of people each year worldwide. The most common etiologic agent of this type of bacterial infections, involving the upper and lower urinary tract, are E. coli strains representing approximately 80% of cases. Uropathogenic E. coli strains produce several urovirulence factors which can be divided into two main types, surface virulence factors and exported virulence factors. Surface-exposed structures include mainly extracellular adhesive organelles such as fimbriae/pili necessary in adhesion, invasion, biofilm formation and cytokine induction. Among the surface-exposed polymeric adhesive structures there are three most invasive groups, type 1 pili, type P pili and Dr family of adhesins which are bioassembled via the conserved, among Gram-negative bacteria, chaperone-usher secretion system. Type 1 and P-piliated E. coli cause cystitis and pyelonephritis. The Dr family of adhesins recognizing DAF receptor is responsible for cystitis, pyelonephritis (especially in pregnant women) and diarrhoea (in infants). In addition, Dr-positive E. coli strains carry the risk of recurrent urinary tract infections. Pyelonephritis in pregnant women leads to a series of complications such as bacteremia, urosepsis, acute respiratory distress syndrome and even death. In the era of increasing drug resistance of bacteria, the development of vaccines, drugs termed pilicides and inhibitors of adhesion may be a promising tool in the fight against urogenital infections.


Author(s):  
Jongsoon Won ◽  
Kyunghee Kim ◽  
Kyeong-Yae Sohng ◽  
Sung-Ok Chang ◽  
Seung-Kyo Chaung ◽  
...  

Background: Many countries around the world are currently threatened by the COVID-19 pandemic, and nurses are facing increasing responsibilities and work demands related to infection control. To establish a developmental strategy for infection control, it is important to analyze, understand, or visualize the accumulated data gathered from research in the field of nursing. Methods: A total of 4854 articles published between 1978 and 2017 were retrieved from the Web of Science. Abstracts from these articles were extracted, and network analysis was conducted using the semantic network module. Results: ‘wound’, ‘injury’, ‘breast’, “dressing”, ‘temperature’, ‘drainage’, ‘diabetes’, ‘abscess’, and ‘cleaning’ were identified as the keywords with high values of degree centrality, betweenness centrality, and closeness centrality; hence, they were determined to be influential in the network. The major topics were ‘PLWH’ (people living with HIV), ‘pregnancy’, and ‘STI’ (sexually transmitted infection). Conclusions: Diverse infection research has been conducted on the topics of blood-borne infections, sexually transmitted infections, respiratory infections, urinary tract infections, and bacterial infections. STIs (including HIV), pregnancy, and bacterial infections have been the focus of particularly intense research by nursing researchers. More research on viral infections, urinary tract infections, immune topic, and hospital-acquired infections will be needed.


2021 ◽  
Vol 10 (Supplement_2) ◽  
pp. S16-S16
Author(s):  
Sara Kim ◽  
Avni Bhatt ◽  
Silvana Carr ◽  
Frances Saccoccio ◽  
Judy Lew

Abstract Background Procalcitonin (PCT) and c-reactive protein (CRP) have been utilized in children to assess risk for serious bacterial infections. However, there have been different cut-offs reported for PCT and CRP, which yield different sensitivity and specificity. This study aims to compare the sensitivity and specificity of PCT and CRP in detecting serious bacterial infections (SBIs), specifically urinary tract infections, bacteremia and meningitis. Methods In this retrospective, single center cohort study from January 2018 to June 2019, we analyzed children with a fever greater than 38C with both PCT and CRP value within 24 hours of admission. Each patient had a blood, urine and/or cerebrospinal fluid culture collected within 48 hours of admission. No antibiotics were administered from the admitting hospital prior to collection of the PCT or CRP. Our gold standard was a positive culture obtained from blood, cerebrospinal fluid, or urine. The statistical analysis included categorical variables as percentages and compared them using the Fisher exact test. The optimal cutoff values for PCT or CRP were based on ROC curve analysis and Youden Index. Sensitivity and specificity analysis were based on literature review cut offs and ROC curves cut offs. Results Among 202 children, we had 45 culture positive patients (11 urinary tract infections, 4 meningitis, and 32 bacteremia). The patients with culture positivity had higher PCT levels (7.9 ng/mL vs 2.5 ng/mL, P=0.0111), CRP levels (110.9 mg/L vs 49.6 mg/L, P<0.0001) and temperature (39.2C vs 39C, P<0.0052). The area under the curve (AUC) comparing culture positivity vs negativity for all culture types was 0.72 (p<0.0001) for PCT and 0.66 (p=0.001) for CRP. In Figure 1, the AUC for culture positive bacteremia was 0.68 (p=0.0011) for PCT and 0.70 (p=0.0003). The AUC for culture positive urinary tract infections (UTI) only was 0.86 (p=0.0001) for PCT and 0.70 (p=0.3607). For the cut-off value for PCT at 0.5 ng/mL, the sensitivity and specificity was 64% (95% confidence interval [CI] 0.5–0.77) and 70% (95% CI 0.62–0.77) respectively in identifying children with bacterial infection. For the cut-off value for CRP at 20 mg/L, the sensitivity and specificity was 67% (95% CI 0.52–0.79) and 52% (95% CI 0.44–0.59) respectively in identifying children with bacterial infection. Conclusion In this study, PCT and CRP are nearly equivalent classifiers for detecting SBIs as a group and bacteremia, but PCT is statistically better for urinary tract infections; however, the clinical utility is unknown.


2021 ◽  
Vol 12 (3) ◽  
pp. 1740-1744
Author(s):  
Eva Lorel Kouassi ◽  
Abdul Wahid Ishaque ◽  
Amulya P. Shetty ◽  
Rimpa Devi ◽  
Sheethal Kuriakose ◽  
...  

Although urinary tract infections (UTIs) are considered to be the most common bacterial infections worldwide, their assessment remains a big clinical challenge, because they are not reportable diseases in developed countries like United States and any other parts of the world including India. This situation is further complicated by the fact that accurate diagnosis depends on both the presence of symptoms and a positive urine culture, although in most outpatient settings this diagnosis is made without the benefit of culture. Our study aimed to appraise the impact of urinary tract infections symptoms on selected patients and comprehend their adherence to medications despite the challenges of antimicrobial susceptibility and resistance observed. One hundred and twenty patients with confirmed cases of urinary tract infections were recruited for the study. The mean age of females and males patients was found to be 59.86±2.37and 52.27±3 years respectively. Pertinent descriptive and inferential statistics were performed. Spearman correlation test revealed a strong positive correlation between overall UTIs’ symptoms and their impact on patients at baseline (0.84) and at follow up (0.799) with p value =0.5. On the other hand the majority of patients were found to be adherent to the medications after discharge. The current study revealed that Urinary tract infections if left untreated can negatively impact the lives of patients suffering from it and hinder their adherence to medications. Consequently, accurate and early assessment of UTIs’ symptoms in clinics and hospitals becomes a necessity.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Panagiota Karananou ◽  
Despoina Tramma ◽  
Socrates Katafigiotis ◽  
Anastasia Alataki ◽  
Alexandros Lambropoulos ◽  
...  

Urinary tract infections are one of the most common and serious bacterial infections in a pediatric population. So far, they have mainly been related to age, gender, ethnicity, socioeconomic level, and the presence of underlying anatomical or functional, congenital, or acquired abnormalities. Recently, both innate and adaptive immunities and their interaction in the pathogenesis and the development of UTIs have been studied. The aim of this study was to assess the role and the effect of the two most frequent polymorphisms of TLR4 Asp299Gly and Thr399Ile on the development of UTIs in infants and children of Greek origin. We studied 51 infants and children with at least one episode of acute urinary tract infection and 109 healthy infants and children. We found that 27.5% of patients and 8.26% of healthy children carried the heterozygote genotype for TLR4 Asp299Gly. TLR4 Thr399Ile polymorphism was found to be higher in healthy children and lower in the patient group. No homozygosity for both studied polymorphisms was detected in our patients. In the group of healthy children, a homozygote genotype for TLR4 Asp299Gly (G/G) as well as for TLR4 Thr399Ile (T/T) was showed (1.84% and 0.92 respectively). These results indicate the role of TLR4 polymorphism as a genetic risk for the development of UTIs in infants and children of Greek origin.


PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e85889 ◽  
Author(s):  
Arne Søraas ◽  
Arnfinn Sundsfjord ◽  
Silje Bakken Jørgensen ◽  
Knut Liestøl ◽  
Pål A. Jenum

2014 ◽  
Vol 5 (3) ◽  
pp. 37-41
Author(s):  
Tatyana Alekseyevna Khusnutdinova ◽  
Yuliya Anatolyevna Savochkina ◽  
Aleksandr Yevgenyevich Gushchin ◽  
Yelena Vasilyevna Shipitsyna ◽  
Alevtina Mikhailovna Savicheva

Urinary tract infections (UTIs) represent the most common bacterial infections and often complicate pregnancy. UTIs in pregnancy are classified by site of bacterial proliferation as follows: asymptomatic bacteriuria, cystitis, pyelonephritis. Screening for asymptomatic bacteriuria is a standard of obstetrical care and is included in most international guidelines. The urine microbiologic culture is considered the gold standard for laboratory diagnosis of UTIs. Molecular methods enable to rapidly detect, identify and quantitate causative agents of UTIs in urine and are effective alternative to traditional bacteriological methods.


2016 ◽  
Vol 10 (5-6) ◽  
pp. 210 ◽  
Author(s):  
Linda C. Lee ◽  
Armando J. Lorenzo ◽  
Martin A. Koyle

Urinary tract infections (UTIs) represent a common bacterial cause of febrile illness in children. Of children presenting with a febrile UTI, 25‒40% are found to have vesicoureteral reflux (VUR). Historically, the concern regarding VUR was that it could lead to recurrent pyelonephritis, renal scarring, hypertension, and chronic kidney disease. As a result, many children underwent invasive surgical procedures to correct VUR. We now know that many cases of VUR are low-grade and have a high rate of spontaneous resolution. The roles of surveillance, antibiotic prophylaxis, endoscopic injection, and ureteral reimplantation surgery also continue to evolve. In turn, these factors have influenced the investigation of febrile UTIs.Voiding cystourethrography (VCUG) is the radiographic test of choice to diagnose VUR. Due to its invasive nature and questionable benefit in many cases, the American Academy of Pediatrics (AAP) no longer recommends VCUG routinely after an initial febrile UTI. Nevertheless, these guidelines pre-date the landmark Randomized Intervention of Children with Vesicoureteral Reflux (RIVUR) trial and there continues to be controversy regarding the diagnosis and management of VUR. This paper discusses the current literature regarding radiographic testing in children with febrile UTIs and presents a practical risk-based approach for deciding when to obtain a VCUG.


Sign in / Sign up

Export Citation Format

Share Document