**2. Urinary tract infections and diagnostics**

Fortunately, the methodologies and procedures of diagnostics are in progress, and the use of molecular techniques (e.g., polymerase chain reaction (PCR)) and advanced pan-genomic

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

tools (e.g., microarray technology) help us to have accurate, sharp, reliable, and rapid detection and identification. Of course, it should be noticed that there is a close relationship between the number of specimens and the applied methodology. In other words, the application of PCR is useful for limited samples, while the microarray technology is a suitable choice when the number of specimens is huge. Thus, the methodologies of diagnosis and treatment should be carefully selected for accurate and definite detection to reduce the number of patients with UTIs [1, 2, 9, 11, 15, 16].

Generally, UTIs are appeared in women ≥18 years old; however, UTIs are recognized in children (girls and boys) and men. In accordance with previous reports, >30% of young women with the age of 24–26 have experienced at least once a diagnosed UTI. Besides, the rUTIs are common among both young and old women with different etiologies. In young women, several sexual intercourses, application of spermicidal devices, and different sexual partners increase the occurrence of rUTIs, while in old women, the lack of vaginal *Lactobacilli* populations, reduction of female hormones, catheterization, and UT surgeries are the most common causes of rUTIs. The patients susceptible to rUTIs are suggested to consume antibiotics as a proper prophylactic method. Besides, the use of some nutrients like cranberry may prevent or reduce the incidence of UTIs and particularly rUTIs in some cases. Interestingly, the rate of asymptomatic or symptomatic bacteriuria increases in both old men and women. But, several studies show that generally the untreated asymptomatic bacteriuria in pregnant women may lead to symptomatic, severe UTIs and even urosepsis. So, treatment of asymptomatic bacteri-

Introductory Chapter: An Overview on Urinary Tract Infections, Pathogens, and Risk Factors

http://dx.doi.org/10.5772/intechopen.82230

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Hospitalization is one of the significant factors associated with UTIs which results in secondary bacteremia. Normally, hospitalization and catheterization are important predisposed factors to nosocomial UTIs because the use of catheters (e.g., bladder catheter) may occur during hospitalization which results in UTIs. In parallel with catheterization, the problem of biofilm formation within catheters and the presence of multidrug-resistant pathotypes relating to microbial causative agents (e.g., ESBLs producing *Enterobacteriaceae*) considerably increase the rate of morbidity and mortality among patients with UTIs. *E. coli* and ESBLs producing *E. coli* are the pioneers of bacterial causative agents of nosocomial UTIs. In addition to bacterial pathogens, the presence of fungal populations and in particular *Candida* spp. must be considered as an important threat for progression of nosocomial UTIs among catheterized patients; hence, the catheters may act as an important source for aggregation of microbial pathogens, which are both antibiotic sensitive and antibiotic resistant. Thus, the use of assays pertaining to antibiotic susceptibilities and broad-spectrum antibiotics are pivotal items to reduce the number of patients with nosocomial UTIs

Microbial pathogenome and virulome are significant factors, which determine the severity of UTIs. UPEC, UPKP, *Proteus* spp., *Pseudomonas aeruginosa*, *Enterococcus* spp., and other microbial pathotypes are able to occur in different types of UTIs in their human hosts. Some of microbial virulence genes are located on plasmids, while the others are situated on chromosomes. So, the presence or absence of microbial virulence genes affects directly on pathogen

Genetic risk factors (e.g., blood group and stone formation) and diseases (hypertension), diabetes, strength of host's immune system, immune deficiency syndromes (e.g., AIDS), immunocompromised patients, spinal cord injuries, etc. are other predisposing factors, which

In this book, which consisted of six chapters, the readers will obtain valuable information

increase the incidence of UTIs among human populations [4, 7, 8, 10, 13, 24].

uria in pregnant women is a must [5, 21–23, 25–27].

virulencity and pathogenicity [1, 2, 4, 12, 14].

regarding UTIs and the related predisposing factors.

[6, 24, 28].

In recent years among several difficulties with UTIs, another problem has risen up quickly; the problem is the appearance of a diversity of antimicrobial-resistant pathogens. A typical example for this challenge is the presence of a wide range of extended spectrum ß-lactamases (ESBLs) producing bacteria and, in particular, ESBLs producing *Enterobacteriaceae*. Although there are several groups of ESBLs producing bacteria in the family of *Enterobacteriaceae*, uropathogenic *Escherichia coli* (UPEC) and uropathogenic *Klebsiella pneumoniae* (UPKP) pathotypes are considered as important members, which are able to produce a variety of ESBLs [12, 17, 18].
