*2.1.3 Biology of* Candida albicans

Candidal colonies seem large, round, white, or cream that emanates a yeasty odor on agar plates at room temperature when grown *in vitro* [25]. By fermentation process, *C. albicans* consumes; glucose and maltose and produce acid and gas, sucrose to acid, but does not ferment lactose, this was a benefit in distinguished it from other *Candida* species. Recently, molecular phylogenetic researches confirm a polyphyletic character in the genus *Candida*. Previously, most yeast that isolated from infected individuals regularly called *Candida* even in absence of a clear indication of relationship to other *Candida* species until the development of molecular methods. For example, three species of candida

which are *C. guilliermondii*, *C. glabrata* and *C. lusitaniae* were misclassified and positioned in other genera until the evolution of phylogenetic reorganization [23].

#### *2.1.4 Epidemiology*

Many regions of the human body like skin and mucosal surfaces are inhabited by numerous candidal species, this colonization carried a commensal nature with the host. The immune condition of the individual plays an effect on the severity of the Candida infections, so, any disturbance in immunity increase the percentage of the host's illness make the host more susceptible to infection with candidiasis. In immunocompromised patients, Candidal infections create main fungal infections [26]. Generally, oropharyngeal candidiasis is the primary illness presented in those patients, because of that malnutrition developed leading to restriction of the action of the treatment [27]. These invasive infections have many challenges against public health lead to cumulative health and economic significances because of the great mortality proportions and amplified expenditure of medical care [28].

Skin, mouth, throat, genitals, and blood are the main body regions that are usually infected with candidiasis. Generally, *Candida spp* sustains as the fourth supreme isolated pathogen from bloodstream infections (BSIs). Most cases of candidaemia are caused by *C. albicans* have been associated with a high mortality rate, while the non-albicans species are responsible for about 23% of candidemia collectively with the rare incidence of mortality. Virulence of these species depends on many elements; capability of biofilms creation, the existence of teleomorph forms, therapeutic difficulty, and resistance to conventional antifungal medicines [29]. Candidal nosocomial infections determined by organ transplantations, an increase of immunosuppression cases, and the clinical procedures that required the usage of invasive devices [30].

#### *2.1.5 Host predisposing factors*

Besides the commensalism interaction between Candida species and humans and the fundamental existence of it in healthy persons, recent two decades showed an unusual overgrowth in respiratory, gastrointestinal, and urinary tracts in comparison with earlier periods. Shortly after childbirth, species colonize the mucosa of the upper respiratory passages and gastrointestinal tract. Habitually, *C. albicans* exists fluently in the internal warm crinkles and fissures of the gastrointestinal tract and vaginal tract. Candidal colonization rises nearly to 30–40% during pregnancy due to disturbance of immunity, bacterial flora, and pH level variations, while about 10% of these species are found in mucosa and skin of the genitalia in men [31].

#### **2.2** *Candida albicans* **and pregnancy**

During pregnancy, females exposed to many physiological changes. Gestation is a complicated condition in fetal development that requires various essential substances such as glucose, fatty acids, amino acids, minerals, and vitamins. These nutrients must continuously apply to improve the process of fetal growth and to protect the health condition of pregnant women. Many pathogens that responsible for several sexual and non-sexual transmitted infections invade the women's bodies through the female genital tract (FGT), leading to vaginal infections. The common clinical symptom for female genital tract infection is vaginal discharge, which considers as the second main gynecological problem after menstrual disorders [32]. Vulvovaginal candidiasis (VVC) (also called candidal vaginitis or

#### Candida albicans *and Abortion DOI: http://dx.doi.org/10.5772/intechopen.97383*

moniliasis) initiated by an overgrowth of candida yeast species mainly *C. albicans*. The main features of this disease are curd-like vaginal discharge, itching, erythema, burning, vulvar and vaginal irritation associated with dysuria and dyspareunia [33]. *C. albicans* overgrowth causes superficial infections such as vaginitis that are usually associated with an immuno-compromised state mucosal candidiasis. Scientific researches fixed that near to 75% of women undergo at minimum one incidence of a genital yeast infection at reproductive years of them, In addition, about 10–20% of women acquire asymptomatic vaginal colonization with Candida species during their life. While 5–10% of healthy women suffering from recurrent vaginal candidiasis without any predisposing factors. In the presentation of chronic recurrent candidiasis, pregnant women are less resistant to VVC in comparison with healthy women. The forms of infection may be acute, chronic, superficial, or deep. During pregnancy, rising in estrogen level will be followed by increasing in glycogen production in the vagina, which improves the proliferation of the yeast on the lining of it. Alterations in physiological conditions that affect the beneficial bacteria in the vagina would change the vaginal acidity reducing its pH to 5.0–6.5. This alteration in pH will increase the overgrowth of pathogenic *Candida*. Several factors such as age, menstrual cycle, sexual activity, pregnancy, and excessive use of antibiotics may lead to an increased vaginal pH [34].

Colonization of the vagina by Candida species may be enhanced by numerous factors such as pregnancy, weak immunity, obesity, diabetes, prolonged use of corticosteroids, HIV, malnutrition, consumption of high level of estrogens, Intrauterine Contraceptive Device (IUCDs), tight clothing, poor personal hygiene, intrauterine devices and diet with high carbohydrates contents. VVC is a significant infection that may lead to abortion, candida chorioamnionitis, subsequent preterm delivery, and suppression of the immune system. Even with the isolation of Other candida *spp* (*Candida tropicalis*) from aborted placenta [35], *C. albicans* considered the main one that can invade the fetal membranes. Uterus infection with candida may be occurring via the usage of IUD that might hold the yeast from contaminated external genitalia into the uterus. In many cases, the pregnancy occurs even with the presence of IUD and that may lead to candidal abortion [5]. In addition, the probability of the presence of *C. albicans* in the uterus was referred to transmit of that yeast via seminal fluid, giving some proves about the role of the male as a reservoir of *C. albicans.* This may lead to re-infection of their sexual partner besides the isolation of that yeast from the genitalia and from semen [36]. In general, the infected male stays asymptomatic carriers and that will add another difficulty to control the yeast spreading. Although its ubiquity in the vagina, intra-amniotic infection with *C. albicans* is rare and that explained the few isolates that detected from the aborted placenta [37].
