*5.7.3. Laboratory diagnosis*

**5.7. CAUTI with Candida**

34 Microbiology of Urinary Tract Infections - Microbial Agents and Predisposing Factors

*5.7.2. Structure and pathogenesis*

One of the common causes of catheter associated urinary tract infection is fungal infection. Bacterial infections are accounted for 70.9% of catheter associated urinary infection. *E. coli* is the most commonly isolated organism (41.6%) whereas fungal infections are accounted for 16.6% and mixed fungal and bacterial infections accounted for 12.5% [68]. The National nosocomial infections surveillance (NNIS) data indicated that *C. albicans* caused 21% of catheterassociated urinary tract infections, in contrast to 13% of non-catheter-associated infections [69]. In one study 24% of the cases showing fungal yeast growth. Candida spp. was the commonest. Non-albicans Candida (86%) isolated more commonly than *Candida albicans* (14%) [70]. Candida are commensals, and to be pathogenic, interruption of normal host defenses is crucial which is facilitated in conditions like immunocompromised states as AIDS, diabetes mellitus, prolonged broad spectrum antibiotic use, indwelling devices, intravenous drug use and hyperalimentation fluids [71]. Diabetes mellitus has been reported as the most common risk factor for fungal infection [72, 73]. The duration of catheterization is also an important

risk factor as the duration increases the incidence of fungal infection is increased [74].

formation, phenotypic switching and a range of fitness attributes [78] (**Figure 7**).

*Candida albicans* is an oval, budding yeast, which is a member of the normal flora of mucocutaneous membrane. Twenty species of Candida yeasts can cause in human infection but most common is *Candida albicans*. Sometimes it can gain predominance and can produce disease. Other candida species that can cause disease occasionally are *Candida parapsilosis*, *Candida tropicalis* and *Candida krusei* [75]. Although *Candida albicans* are common isolates in CAUTI, *Candida tropicalis* is increasingly reported in CAUTI [76]. The majority of *Candida albicans* infections are associated with biofilm formation on host or abiotic surfaces such as indwelling medical devices, which carry high morbidity and mortality [63, 77]. Several factors and activities contribute to the pathogenesis of this fungus which mediate adhesion to and invasion into host cells, which are in sequences are the secretion of hydrolases, the yeast-to-hypha transition, contact sensing and thigmotropism, biofilm

**Figure 7.** Morphology of Candida albicans. Adapted from biomedik8888, Aug 24, 2011. http://www.BioMedik.com.au3.

*5.7.1. Introduction*

Urine and materials removed from catheter are needed. Microscopic examinations of gramstained specimen showed pseudohyphae and budding cells. Culture on Sabouraud's agar at room temperature and at 37°C showed typical colonies and budding pseudomycelia [79].
