Studies of Immune Responses in Candida vaginitis

Candida albicans: the current status regarding vaginal infections

Vaginal infections caused by Candida albicans are a significant global health concern due to their recurrence and negative impact on quality of life. This review examines the pathogenesis of C. albicans infections, emphasizing critical virulence factors such as biofilm formation, adherence, and phenotypic switching. Risk factors include immune system suppression, antibiotic use, and hormonal changes, all of which can lead to fungal overgrowth and infection. Current prevention and/or treatment strategies primarily rely on antifungal therapies, personal hygiene practices, and probiotics. However, challenges like antifungal resistance, recurrence, and limited treatment efficacy highlight the need for innovative approaches. Therefore, emerging methods such as novel antifungal agents, vaccines, and nanotechnology-based delivery systems offer promising advancements to improve infection control. Additionally, the immune system plays a key role in preventing C. albicans infections, with both innate and adaptive immunity acting to restrict fungal colonization and growth. Commercially available products, such as antifungal creams, vaginal probiotics, and hygiene solutions, are practical options but often lack long-term efficacy. Persistent challenges, including resistance, patient noncompliance, and restricted access to emerging therapies, hinder comprehensive prevention and treatment efforts. Thus, future research should focus on promoting interdisciplinary approaches, integrating personalized medicine, and enhancing healthcare accessibility. This review intends to present the current state of the art within the abovementioned issues and to enhance the understanding of the multifactorial nature of C. albicans infections and advanced prevention strategies, which are essential to reduce the burden of vaginal candidiasis worldwide and improve patient quality of life outcomes. KEY POINTS: • Candida albicans pathogenesis involves biofilms, adherence, and phenotypic switching. • Vaccines, nanotechnology, and new drugs offer improved prevention and treatment. • Addressing antifungal resistance and patient compliance is key for prevention success.

Prevalence of Trichomoniasis and Vulvovaginal Candidiasis among Married Women in Duhok City, Kurdistan Region, Iraq

Trichomonas vaginalis and Candida spp. are the most common causes of vaginal infections among reproductive-age women. T. vaginalis is a sexual protozoa parasite that causes trichomoniasis. Candida spp. are fungal and cause infection in the female genital tract named candidiasis. Both microorganisms if not treated correctly may lead to various complications, such as abortion, premature delivery, disorders of menstrual cycle, and infertility. The current study aimed to study the frequency of infections with T. vaginalis and Candida spp., including C. albicans, C. krusei, and C. glabrata, among females with vaginal infection in Duhok City, Kurdistan region, Iraq. A total of 400 vaginal swabs were collected from women with vaginal infections that attended the Vin Private Laboratory (n=250) and Arveen Private Laboratory (n=150). Out of these 400 vaginal swabs samples, 24 samples were recorded positive for T. vaginalis by direct smear and 100 samples for candidiasis by culturing on the CHROMagarTM Candida. Three species of Candida were isolated, namely C. albicans, C. krusei, and C. glabrata, and their prevalence rates were obtained at 60.9%., 28.25, 7.3%, and 3.6%, respectively. Vaginal infection was commonly found in the age group of 25-35 years (49.6%), followed by the age group of 35-45 years (36.4%). Moreover, 3.2% of samples were found to have a mixed infection with trichomoniasis and candidiasis. Because these two causative agents cause numerous complications in women, it is highly recommended proper controlling measures, such as health education, personal hygiene, and treatment of infected women, be implemented to prevent or decrease vaginal infection.

Promising immunotherapeutic targets for treating candidiasis

In the last twenty years, there has been a significant increase in invasive fungal infections, which has corresponded with the expanding population of individuals with compromised immune systems. As a result, the mortality rate linked to these infections remains unacceptably high. The currently available antifungal drugs, such as azoles, polyenes, and echinocandins, face limitations in terms of their diversity, the escalating resistance of fungi and the occurrence of significant adverse effects. Consequently, there is an urgent need to develop new antifungal medications. Vaccines and antibodies present a promising avenue for addressing fungal infections due to their targeted antifungal properties and ability to modulate the immune response. This review investigates the structure and function of cell wall proteins, secreted proteins, and functional proteins within C. albicans. Furthermore, it seeks to analyze the current advancements and challenges in macromolecular drugs to identify new targets for the effective management of candidiasis.

Viral protein-based nanoparticles (part 2): Pharmaceutical applications

Viral protein nanoparticles (ViP NPs) such as virus-like particles and virosomes are structures halfway between viruses and synthetic nanoparticles. The biological nature of ViP NPs endows them with the biocompatibility, biodegradability, and functional properties that many synthetic nanoparticles lack. At the same time, the absence of a viral genome avoids the safety concerns of viruses. Such characteristics of ViP NPs offer a myriad of opportunities for theirapplication at several points across disease development: from prophylaxis to diagnosis and treatment. ViP NPs present remarkable immunostimulant properties, and thus the vaccination field has benefited the most from these platforms capable of overcoming the limitations of both traditional and subunit vaccines. This was reflected in the marketing authorization of several VLP- and virosome-based vaccines. Besides, ViP NPs inherit the ability of viruses to deliver their cargo to target cells. Because of that, ViP NPs are promising candidates as vectors for drug and gene delivery, and for diagnostic applications. In this review, we analyze the pharmaceutical applications of ViP NPs, describing the products that are commercially available or under clinical evaluation, but also the advances that scientists are making toward the implementation of ViP NPs in other areas of major pharmaceutical interest.

Viral protein nanoparticles (Part 1): Pharmaceutical characteristics

Viral protein nanoparticles fill the gap between viruses and synthetic nanoparticles. Combining advantageous properties of both systems, they have revolutionized pharmaceutical research. Virus-like particles are characterized by a structure identical to viruses but lacking genetic material. Another type of viral protein nanoparticles, virosomes, are similar to liposomes but include viral spike proteins. Both systems are effective and safe vaccine candidates capable of overcoming the disadvantages of both traditional and subunit vaccines. Besides, their particulate structure, biocompatibility, and biodegradability make them good candidates as vectors for drug and gene delivery, and for diagnostic applications. In this review, we analyze viral protein nanoparticles from a pharmaceutical perspective and examine current research focused on their development process, from production to administration. Advances in synthesis, modification and formulation of viral protein nanoparticles are critical so that large-scale production of viral protein nanoparticle products becomes viable and affordable, which ultimately will increase their market penetration in the future. We will discuss their expression systems, modification strategies, formulation, biopharmaceutical properties, and biocompatibility.

Our pursuit for effective antifungal agents targeting fungal cell wall components, where are we?

Invasive mycotic infections account for an unacceptably high mortality rates in humans. These infections are initiated by the fungal cell wall which mediates host-fungi interactions. The cell wall is fused to the physiology of fungi, and it is involved in essential functions in the entire cell functionality. Components of the cell wall are synthesised and modified in the cell wall space by the activities of cell wall proteins through a range of signalling pathways that have only been described in many fungi, therefore making them suitable drug targets. The echinocandins class of cell wall-active drugs block cell wall β-1,3-glucan biosynthesis through inhibiting the catalytic subunit of the synthetic protein complex. Resistance to echinocandins can be through the acquisition of single nucleotide polymorphisms and/or through activation of cell wall signalling pathways resulting in altered cell wall proteome and elevated chitin content in the cell wall. Countering the cell wall remodelling process will enhance the effectiveness of β-1,3-glucan-active antifungal agents. Cell surface proteins are also important antifungal targets which can be used to develop rapid and robust diagnostics and more effective therapeutics. The cell wall remains a crucial target in fungi that needs to be harnessed to combat mycotic infections.

Vaginal pH Value for Clinical Diagnosis and Treatment of Common Vaginitis

In modern society, 75% of all women worldwide have had vaginitis at least once in their lives. The vagina has a dynamic microbial ecosystem with varying vaginal pH levels. An imbalance in that ecosystem can alter the vaginal pH and tip the scale to the point of causing issues, such as vaginitis, that require medical attention. Although vaginitis is not an incurable disease, it causes discomfort and pain that disrupt women's daily lives. The most common causes of vaginitis include bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis. In this review, we discuss the causes, diagnostic methods, and symptoms of different types of vaginitis, the relationship of vaginitis to the prevalence of other diseases, issues associated with recurrent vaginitis and the immune system, and a variety of effective available treatments. In our article, we summarize the relationship of pH with the vaginal ecosystem, discuss the associated factors of vaginal pH, and finally introduce the different available vaginal pH self-test products.

The Role of B-Cells and Antibodies against Candida Vaccine Antigens in Invasive Candidiasis

Systemic candidiasis is an invasive fungal infection caused by members of the genus Candida. The recent emergence of antifungal drug resistance and increased incidences of infections caused by non-albicans Candida species merit the need for developing immune therapies against Candida infections. Although the role of cellular immune responses in anti-Candida immunity is well established, less is known about the role of humoral immunity against systemic candidiasis. This review summarizes currently available information on humoral immune responses induced by several promising Candida vaccine candidates, which have been identified in the past few decades. The protective antibody and B-cell responses generated by polysaccharide antigens such as mannan, β-glucan, and laminarin, as well as protein antigens like agglutinin-like sequence gene (Als3), secreted aspartyl proteinase (Sap2), heat shock protein (Hsp90), hyphally-regulated protein (Hyr1), hyphal wall protein (Hwp1), enolase (Eno), phospholipase (PLB), pyruvate kinase (Pk), fructose bisphosphate aldolase (Fba1), superoxide dismutase gene (Sod5) and malate dehydrogenase (Mdh1), are outlined. As per studies reviewed, antibodies induced in response to leading Candida vaccine candidates contribute to protection against systemic candidiasis by utilizing a variety of mechanisms such as opsonization, complement fixation, neutralization, biofilm inhibition, direct candidacidal activity, etc. The contributions of B-cells in controlling fungal infections are also discussed. Promising results using anti-Candida monoclonal antibodies for passive antibody therapy reinforces the need for developing antibody-based therapeutics including anti-idiotypic antibodies, single-chain variable fragments, peptide mimotopes, and antibody-derived peptides. Future research involving combinatorial immunotherapies using humanized monoclonal antibodies along with antifungal drugs/cytokines may prove beneficial for treating invasive fungal infections.

Virulence Factors as Promoters of Chronic Vulvovaginal Candidosis: A Review

INTRODUCTION

The vast majority of the species of the genus Candida spp. is commensal in humans; however, some are opportunistic pathogens that can cause infection, called candidosis. Among the different types of candidosis, we highlight the vulvovaginal (VVC) which can occur in two main clinical variants: chronic (cVVC) and episodic or sporadic. The incidence of cVVC has been worrying the scientific community, promoting the research on genotypic and phenotypic causes of its occurrence. We summarize important findings on factors that favor chronic vulvovaginal candidosis with respect to molecular epidemiology and the expression of various virulence factors, while clarifying the terminology involving these infections.

AIM AND METHODOLOGY

The aim of this review was to gather research that linked virulence factors to VVC and its persistence and recurrence, using two databases (Pubmed and Google Scholar). Predisposing factors in women for the occurrence of cVVC and some studies that refer new preventive and alternative therapies were also included, where appropriate.

RESULTS AND DISCUSSION

Several studies have been shedding light on the increasing number of persistence and recurrences of VVC. The expression of virulence factors has been related to both chronic forms of VVC and antifungal resistance. Other studies report mutations occurring in the genome of Candida spp. during the infection phase which may be important indications for new therapies. The introduction of preventive therapies and new therapies has revealed great importance and is also highlighted here.

Vulvovaginal candidiasis and current perspectives: new risk factors and laboratory diagnosis by using MALDI TOF for identifying species in primary infection and recurrence

Vulvovaginal candidiasis (VVC), considered the second cause of genital infection among women, has pathogenic mechanisms still to be elucidated and unknown risk factors. Prevalence studies with laboratory diagnosis (at first diagnosis and recurrence) are uncommon, especially using MALDI TOF, used in this clinical, epidemiological, and laboratory study for evaluating candidiasis, and identifying unknown risk factors. To obtain clinical and epidemiological data, patients were questioned, and there was material collection. Samples collected were identified by using phenotypic and presumptive methods and confirmed by MALDI TOF. This study analyzed 278 patients, divided into symptomatic (n = 173) and asymptomatic (n = 105) groups. Regarding the main candidiasis symptoms (discharge, itching, and burning), only 50.3% of patients described these concomitant symptoms, showing a positive predictive value of 67.8%. Regarding the risk factors investigated, there was a statistical correlation between candidiasis and dairy products, gut transit, contraceptive use, respiratory allergy, and panty liners, describing new risk factors related to intestinal and vaginal dysbiosis. After Candida species analysis and confirmation, the primary prevalence was 80.9% (Candida albicans), 15.2% (non-albicans), 1% (Rhodotorula mucilaginosa), and 1.9% (unidentified species). In recurrence, the prevalence was 66.7% (C. albicans) and 33.3% (non-albicans). The presence of symptoms has low positive predictive value for the diagnosis of candidiasis, even when considering the classic triad of symptoms. Laboratory identification of yeast species is essential for correct treatment, preventing the resistance to antifungals and the high recurrence. In addition, dairy products and bowel habits, both related to intestinal and vaginal dysbiosis, may be associated with VVC.

The effect of benzyl isothiocyanate on Candida albicans growth, cell size, morphogenesis, and ultrastructure

Candida albicans is a commensal yeast that may become pathogenic and even lethal to the host. Over the last few decades, antifungal resistance has increased, promoting screening of the antifungal potential of old and new substances. This study investigates the antifungal potential of isothiocyanates (ITCs) against C. albicans oral isolates. A preliminary susceptibility disk diffusion test (DD) was performed using allyl isothiocyanate (AITC), benzyl isothiocynanate (BITC) and phenyl ethyl isothiocyanate (PEITC) at a fixed concentration range (0.001-0.1 M). Because C. albicans isolates were more susceptible to BITC and PEITC, their effect on cell size and on germ tube formation (GTF) were tested. The most promising molecule, BITC, was further tested for effects on cell viability, oxidative stress and for ultrastructure. ITCs, especially the aromatic ones, had a significant type-, dose- and isolate-dependent anti-Candida activity. Although BITC and PEITC had similar activity against the yeast cells, BITC had a more pronounced effect on cell size and GTF. Furthermore, BITC appears to induce oxidative stress and promote changes in the cell ultrastructure, interfering with cell wall structure. Our work showed that aromatic ITCs have the potential to effect C. albicans cells in multiple ways, including size, shape and GTF (BITC and PEITC), oxidative stress, and ultrastructure (BITC). Overall, our results suggest that BITC may be effectively used against C. albicans to modulate its growth, and control or suppress its invasive potential.

Protective effect of fungal extracellular vesicles against murine candidiasis

Extracellular vesicles (EVs) are lipid bilayered compartments released by virtually all living cells, including fungi. Among the diverse molecules carried by fungal EVs, a number of immunogens, virulence factors and regulators have been characterised. Within EVs, these components could potentially impact disease outcomes by interacting with the host. From this perspective, we previously demonstrated that EVs from Candida albicans could be taken up by and activate macrophages and dendritic cells to produce cytokines and express costimulatory molecules. Moreover, pre-treatment of Galleria mellonella larvae with fungal EVs protected the insects against a subsequent lethal infection with C. albicans yeasts. These data indicate that C. albicans EVs are multi-antigenic compartments that activate the innate immune system and could be exploited as vaccine formulations. Here, we investigated whether immunisation with C. albicans EVs induces a protective effect against murine candidiasis in immunosuppressed mice. Total and fungal antigen-specific serum IgG antibodies increased by 21 days after immunisation, confirming the efficacy of the protocol. Vaccination decreased fungal burden in the liver, spleen and kidney of mice challenged with C. albicans. Splenic levels of cytokines indicated a lower inflammatory response in mice immunised with EVs when compared with EVs + Freund's adjuvant (ADJ). Higher levels of IL-12p70, TNFα and IFNγ were detected in mice vaccinated with EVs + ADJ, while IL-12p70, TGFβ, IL-4 and IL-10 were increased when no adjuvants were added. Full protection of lethally challenged mice was observed when EVs were administered, regardless the presence of adjuvant. Physical properties of the EVs were also investigated and EVs produced by C. albicans were relatively stable after storage at 4, -20 or -80°C, keeping their ability to activate dendritic cells and to protect G. mellonella against a lethal candidiasis. Our data suggest that fungal EVs could be a safe source of antigens to be exploited in vaccine formulations.

Estimated Burden of Fungal Infections in Namibia

Namibia is a sub-Saharan country with one of the highest HIV infection rates in the world. Although care and support services are available that cater for opportunistic infections related to HIV, the main focus is narrow and predominantly aimed at tuberculosis. We aimed to estimate the burden of serious fungal infections in Namibia, currently unknown, based on the size of the population at risk and available epidemiological data. Data were obtained from the World Health Organization (WHO), Joint United Nations Programme on HIV/AIDS (UNAIDS), and published reports. When no data existed, risk populations were used to estimate the frequencies of fungal infections, using the previously described methodology. The population of Namibia in 2011 was estimated at 2,459,000 and 37% were children. Among approximately 516,390 adult women, recurrent vulvovaginal candidiasis (≥4 episodes /year) is estimated to occur in 37,390 (3003/100,000 females). Using a low international average rate of 5/100,000, we estimated 125 cases of candidemia, and 19 patients with intra-abdominal candidiasis. Among survivors of pulmonary tuberculosis (TB) in Namibia 2017, 112 new cases of chronic pulmonary aspergillosis (CPA) are likely, a prevalence of 354 post-TB and a total prevalence estimate of 453 CPA patients in all. Asthma affects 11.2% of adults, 178,483 people, and so allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) were estimated in approximately 179/100,000 and 237/100,000 people, respectively. Invasive aspergillosis (IA) is estimated to affect 15 patients following leukaemia therapy, and an estimated 0.13% patients admitted to hospital with chronic obstructive pulmonary disease (COPD) (259) and 4% of HIV-related deaths (108) — a total of 383 people. The total HIV-infected population is estimated at 200,000, with 32,371 not on antiretroviral therapy (ART). Among HIV-infected patients, 543 cases of cryptococcal meningitis and 836 cases of Pneumocystis pneumonia are estimated each year. Tinea capitis infections were estimated at 53,784 cases, and mucormycosis at five cases. Data were missing for fungal keratitis and skin neglected fungal tropical diseases such as mycetoma. The present study indicates that approximately 5% of the Namibian population is affected by fungal infections. This study is not an epidemiological study—it illustrates estimates based on assumptions derived from similar studies. The estimates are incomplete and need further epidemiological and diagnostic studies to corroborate, amend them, and improve the diagnosis and management of these diseases.

Is mannose-binding lectin serum concentration a reliable predictor for recurrent vulvovaginal candidiasis?

Recurrent vulvovaginal candidiasis (RVVC) is a common opportunistic, mucosal fungal infection, predominantly caused by the fungus Candida albicans. Mannose-binding lectin (MBL) is an acute-phase protein that plays a key role in the innate immunity defence against infectious disease. This study was conducted to evaluate the relationship between the MBL serum level and the relative expression of MBL mRNA in RVVC using real-time PCR for the first time. The case-control study included 40 female participants suffering from RVVC and 40 healthy individuals. The MBL serum level was measured using a commercial ELISA kit. The relative mRNA expression of the MBL gene was quantified using real-time PCR. Data analysis was carried out by spss software. The MBL concentration was significantly higher in the participants suffering from RVVC compared to the control group (0.330 ng/mL vs 0.253 ng/mL). The prognostic value (P < .001) for RVVC diagnosis has been calculated. Quantitative RT-PCR results from 35 samples showed a low to significant values for mRNA levels corresponding to MBL gene expression (1-352 folds) (P < .001). The results of this study suggest that MBL plays a main role in the innate immunity and it is also affected by environmental factors and other genetic variations. Therefore, the MBL gene expression profile does not reflect precise phenotypic levels in the serum.

Mucosal Vaccine Approaches for Prevention of HIV and SIV Transmission

Optimal protective immunity to HIV will likely require that plasma cells, memory B cells and memory T cells be stationed in mucosal tissues at portals of viral entry. Mucosal vaccine administration is more effective than parenteral vaccine delivery for this purpose. The challenge has been to achieve efficient vaccine uptake at mucosal surfaces, and to identify safe and effective adjuvants, especially for mucosally administered HIV envelope protein immunogens. Here, we discuss strategies used to deliver potential HIV vaccine candidates in the intestine, respiratory tract, and male and female genital tract of humans and nonhuman primates. We also review mucosal adjuvants, including Toll-like receptor agonists, which may adjuvant both mucosal humoral and cellular immune responses to HIV protein immunogens.

Targeting Glycans on Human Pathogens for Vaccine Design

Glycosylation is an important post-translational modification that is required for structural and stability purposes and functional roles such as signalling, attachment and shielding. Many human pathogens such as bacteria display an array of carbohydrates on their surface that are non-self to the host; others such as viruses highjack the host-cell machinery and present self-carbohydrates sometimes arranged in a non-self more immunogenic manner. In combination with carrier proteins, these glycan structures can be highly immunogenic. During natural infection, glycan-binding antibodies are often elicited that correlate with long-lasting protection. A great amount of research has been invested in carbohydrate vaccine design to elicit such an immune response, which has led to the development of vaccines against the bacterial pathogens Haemophilus influenzae type b, Streptococcus pneumonia and Neisseria meningitidis. Other vaccines, e.g. against HIV-1, are still in development, but promising progress has been made with the isolation of broadly neutralizing glycan-binding antibodies and the engineering of stable trimeric envelope glycoproteins. Carbohydrate vaccines against other pathogens such as viruses (Dengue, Hepatitis C), parasites (Plasmodium) and fungi (Candida) are at different stages of development. This chapter will discuss the challenges in inducing cross-reactive carbohydrate-targeting antibodies and progress towards carbohydrate vaccines.

Biofilms Formed by Isolates from Recurrent Vulvovaginal Candidiasis Patients Are Heterogeneous and Insensitive to Fluconazole

Vulvovaginal candidiasis (VVC) is a global health problem affecting ∼75% of women at least once in their lifetime. Here we examined the epidemiology of VVC in a patient cohort to identify the causative organisms associated with VVC. Biofilm-forming capacity and antifungal sensitivity profiles were also assessed. We report a shifting prevalence of Candida species with heterogeneous biofilm-forming capacity, which is associated with altered antifungal drug sensitivity.

Candida and its dual lifestyle as a commensal and a pathogen

Candida spp. are part of the normal vaginal microflora in 20-30% of healthy women. However, if the balance between these yeasts and the host is disturbed, Candida spp. can cause vulvovaginal candidiasis (VVC), with Candida albicans being the major causative agent. Different studies have been performed in order to better understand Candida's dual lifestyle in the vagina. The potential of C. albicans to switch from the yeast cell morphology to its hyphal form is considered a key element in VVC pathogenesis. Candida spp. also express other virulence factors, such as hydrolytic extracellular enzymes and heat shock proteins and can form biofilms.

Prevalence of Trichomonas vaginalis and Candida albicans among Brazilian Women of Reproductive Age

INTRODUCTION

There are no studies assessing the simultaneous occurrence of Candida albicans (C. albicans) and Trichomonas vaginalis (T. vaginalis) in the primary health care in Brazil. Despite different conditions to establishment of each one, the co-detection of both has been reported by some authors in previous studies from other regions.

AIM

To compare the prevalence of T. vaginalis and C. albicans in correlation with associated variables.

MATERIALS AND METHODS

A cross-sectional study conducted in a family health clinic in the Federal District of Brazil, between November 2014 and March 2015. Vaginal swabs were collected from 201 women of the reproductive age selected from women registered at the family health clinic. Minors and pregnant women were excluded. The rates of T. vaginalis and Candida albicans prevalence were evaluated with vaginal pH, the whiff test, sexual practices and other social and demographic variables. Difference between proportions was assessed by Z-Test.

RESULTS

C. albicans was present in 20% of the women, while 16% of them had T. vaginalis. The simultaneous occurrence of the agents was found in 1.5%. Significant differences were found between prevalence rates for the variables race/skin colour, practice of anilingus and lifetime number of sexual partners.

CONCLUSION

The prevalence of T. vaginalis exceeds C.albicans among women with higher numbers of sexual partners. The prevalence of C. albicans was higher than T. vaginalis among white women and those who practice active and receptive anilingus. The simultaneous occurrence of the two microorganisms was uncommon.

Candida albicans Pathogenesis: Fitting within the Host-Microbe Damage Response Framework

Historically, the nature and extent of host damage by a microbe were considered highly dependent on virulence attributes of the microbe. However, it has become clear that disease is a complex outcome which can arise because of pathogen-mediated damage, host-mediated damage, or both, with active participation from the host microbiota. This awareness led to the formulation of the damage response framework (DRF), a revolutionary concept that defined microbial virulence as a function of host immunity. The DRF outlines six classifications of host damage outcomes based on the microbe and the strength of the immune response. In this review, we revisit this concept from the perspective of Candida albicans, a microbial pathogen uniquely adapted to its human host. This fungus commonly colonizes various anatomical sites without causing notable damage. However, depending on environmental conditions, a diverse array of diseases may occur, ranging from mucosal to invasive systemic infections resulting in microbe-mediated and/or host-mediated damage. Remarkably, C. albicans infections can fit into all six DRF classifications, depending on the anatomical site and associated host immune response. Here, we highlight some of these diverse and site-specific diseases and how they fit the DRF classifications, and we describe the animal models available to uncover pathogenic mechanisms and related host immune responses.

Total Protein Profile and Drug Resistance in Candida albicans Isolated from Clinical Samples

This study was done to assess the antifungal susceptibility of clinical isolates of Candida albicans and to evaluate its total protein profile based on morphological difference on drug resistance. Hundred and twenty clinical isolates of C. albicans from various clinical specimens were tested for susceptibility against four antifungal agents, namely, fluconazole, itraconazole, amphotericin B, and ketoconazole. A significant increase of drug resistance in clinical isolates of C. albicans was observed. The study showed 50% fluconazole and itraconazole resistance at 32 μg mL(-1) with a MIC50 and MIC90 values at 34 and 47 and 36 and 49 μg mL(-1), respectively. All isolates were sensitive to amphotericin B and ketoconazole. The SDS-PAGE protein profile showed a prevalent band of ~52.5 kDa, indicating overexpression of gene in 72% strains with fluconazole resistance. Since the opportunistic infections of Candida spp. are increasing along with drug resistance, the total protein profile will help in understanding the evolutionary changes in drug resistance and also to characterize them.