Bronchopulmonary candidiasis in a tertiary referral hospital of Assam, India

One hundred patients with chronic chest infection suffering for more than three months admitted into a tertiary referral Hospital, northeast India were examined for pulmonary mycoses. The morning sputum samples in 3 consecutive days with a throat swab of each patient were examined for detection, isolation and identification of the fungus. Study showed Pulmonary candidiasis in 50% of the patients where Candida albicans were having highest incidence of association followed by 5 other species of Candida. Pre-existing conditions like pulmonary tuberculosis, bronchogenic carcinoma, lung abscess, bronchial asthma make the lungs prone to be invaded by the candida species. Long term antibiotics and steroids therapy was found to be associated with pulmonary candidiasis. Other conditions like irradiation treatment, malignancy, diabetes mellitus and malnutrition were also found to be the predisposing factors which influence bronchopulmonary candidiasis.     

The future of antifungal agents. Non azole antifungal agents]

We investigated the efficacy of non-azole antifungal agents. Long circulating immunoliposomal amphotericin B was potent in murine invasive pulmonary aspergillosis. The concentration of AMPH-B was still high in the lung after 6 hours of 34A-PEG-liposomal AMPH-B. Lipid nanosphere amphotericin B (NS-718) showed efficacy against pulmonary aspergillosis in rats and pulmonary cryptococcosis in mice. The renal toxicity of NS-718 was estimated to be lower than that of AMPH-B from the results of the toxicity study in the rat infusion model. FK 463, a novel (1,3)-beta-D-glucan synthase inhibitor, showed efficacy against azole-resistant Candida albicans in murine experimental disseminated candidiasis. FK463 could be a promising drug and the therapy of choice for azole resistant C. albicans infection.     

Detection of serum Candida antigens by enzyme-linked immunosorbent assay and a latex agglutination test with anti-Candida albicans and anti-Candida krusei antibodies.

Serum samples from 197 patients with and without candidiasis were assayed for Candida albicans mannan and Candida krusei mannan by an enzyme-linked immunosorbent assay (ELISA) and a latex agglutination test (LA) and for D-arabinitol by the enzymatic fluorometric method. Of the 43 patients positive for C. albicans mannan (> or = 0.2 ng/ml), 34 were infected with C. albicans and 9 were infected with Candida tropicalis. C. krusei mannan (> or = 0.3 ng/ml) was detected in 10 patients infected with Candida parapsilosis, 2 patients infected with Candida guilliermondii, and 1 patient infected with C. krusei. With both anti-C. albicans antibodies and anti-C. krusei antibodies, the sensitivities of ELISA and LA for detection of invasive candidiasis (58 patients) were 74 and 38%, respectively. No false-positive reactions were observed by the ELISA or the LA. The sensitivity and specificity of the D-arabinitol/creatinine ratio (> or = 1.5 mumol/mg) to invasive candidiasis were 50 and 91%, respectively. The ELISA with antibodies against both C. albicans and C. krusei may be useful in diagnosing invasive candidiasis caused by medically important Candida strains excluding Candida glabrata.     

A case report of pulmonary infiltration with eosinophilia syndrome induced by Candida albicans]

A sixty six-year-old female who had been treated for bronchial asthma for about 25 years was admitted to the hospital with complaints of episodes of dyspnea, eosinophilia and infiltrative shadows in the chest X-ray film. An infiltrative shadow appeared to move from the left to the right lung field and finally formed a shadow of atelectasis in the middle field of the right lung. A sputum culture showed only Candida albicans. Allergic and immunologic examination revealed high IgE serum levels with specific IgE against Candida albicans in high titer, and Aspergillus fumigatus in low titer. The precipitating antibody was shown only against Candida antigen. Additionally, the blastogenic response to Candida antigen was high in comparison with other fungal antigens including Aspergillus fumigatus. The clinical features and laboratory findings of this patient were found to satisfy Rosenberg's criteria for allergic bronchopulmonary aspergillosis (ABPA), except for the existence of Candida albicans in place of Aspergillus species as the causative antigen. The pathogenesis of PIE syndrome has been studied and various allergic mechanisms against many antigens reported. In this patient Candida albicans could be playing the crucial role in the formation of PIE syndrome, which might be best described as allergic bronchopulmonary candidiasis (ABPC).     

In vitro and in vivo antifungal activities of FX0685, a novel triazole antifungal agent with potent activity against fluconazole-resistant Candida albicans.

To evaluate the therapeutic potential of FX0685, a new triazole antifungal agent, for the treatment of opportunistic fungal infections, particularly systemic candidiasis and aspergillosis, in vitro and in vivo studies were performed using fluconazole (FLC), itraconazole (ITC) and/or amphotericin B (AMB) as reference drugs. A preliminary in vitro study showed that the antifungal activity of FX0685 against FLC-susceptible Candida albicans, several non-C. albicans Candida species and Cryptococcus neoformans was superior to that of FLC and comparable or superior to those of ITC and AMB, while the anti-Aspergillus fumigatus activity of FX0685 was to varying degrees lower than that of ITC. FX0685 appeared to be comparable to FLC and ITC in the treatment of murine systemic C. albicans and pulmonary A. fumigatus infection, respectively. The biological property of FX0685 was characterized by its potent in vitro and in vivo activity against FLC-resistant C. albicans. Part of this unique property was explained by the finding that it retained potent inhibitory activity against those CYP51 molecules in which amino acid substitutions confer a phenotype of resistance to FLC and some other azole derivatives. All of these results lead to the possibility that FX0685 may be a potential antifungal drug candidate for the treatment of various clinical forms of systemic candidiasis, including those caused by FLC-resistant C. albicans, as well as for the treatment of pulmonary aspergillosis.     

Antifungal activity and clinical efficacy of micafungin (funguard)]

Micafungin (MCFG) is a new lipopeptide antifungal agent of the echinocandin class. MCFG inhibits 1,3-beta-D-glucan synthesis in C. albicans and A. fumigatus in a non-competitive manner, and has antifungal activity against both Aspergillus and Candida species. In neutropenic mouse models of disseminated candidiasis and pulmonary aspergillosis, the efficacy of MCFG was superior to that of fluconazole and itraconazole, but comparable to that of amphotericin B. The efficacy and safety of MCFG were investigated in 70 patients with deep-seated mycosis caused by Candida and Aspergillus species. The overall clinical response rates were 57.1% in aspergillosis and 78.6% in candidiasis. The incidence of adverse events related to micafungin was 17.9%, and there was no dose-related occurrence of any adverse events. The results from this study indicated that micafungin was effective in aspergillosis and candidiasis, with no tolerability problems.     

Values and limitations of the detection of circulating Candida antigen (Cand-Tec) in the diagnosis of deep candidiasis

Diagnosis of systemic candidiasis is difficult and often performed lately. It can be improved by Candida antigen detection, using agglutination of latex particles sensitized with anti-Candida albicans antibody. Candida antigen search was made in 407 sera obtained from 123 patients, in Hematology and in intensive care units. Fourty three patients had, at least, one serum positive for antigen. The titer was 1/2, 1/4 and 1/8. Twenty seven of the 43 patients had C. albicans in one or several localizations. Eight of these 27 patients had a systemic candidiasis: C. albicans grown from three blood samples, at least, and/or from organ biopsy. In these eight patients, the antigen titer was 1/4 ou 1/8. Eighty patients were Candida antigen negative. Thirty eight out of 80 had C. albicans in one or more sites and two of these 38 had systemic candidiasis. Five other patients had other Candida species. Two out of five had C. tropicalis and C. guillermondii septicemia.     

Enzyme-linked immunosorbent assay measurement of fluctuations in antibody titer and antigenemia in cancer patients with and without candidiasis.

Antibody titers against purified sulfate-soluble fraction (PSSF) obtained from cytoplasmic extracts of Candida albicans were determined retrospectively over a 2-year period for 123 cancer patients by enzyme-linked immunosorbent assay. Antibody against cell wall mannan (CWM) was also measured by the hemagglutination test and the production of precipitins by a serum interacting with a yeast cell homogenate by immunodiffusion. Invasive candidiasis determined by histological evidence at autopsy was present in 10 patients. Fourfold or greater rises in anti-CWM and anti-PSSF antibodies were detected for eight of the patients with invasive candidiasis at 14 to 22 days after the onset of fever. The immunodiffusion test was positive for four patients with invasive candidiasis. For patients with no evidence of candidiasis, significant rises in anti-CWM and anti-PSSF antibodies were observed at a frequency of 20 and 10%, respectively. The concentrations of serum mannan were sequentially measured by the enzyme-linked immunosorbent assay. Antigenemia (greater than or equal to 3 ng/ml) was found in 9 of the 10 patients with invasive candidiasis and in 2 of the 4 patients with thrush, whereas the serum of 1 of the 36 patients with no evidence of candidiasis was positive for antigen. The first antigenemia antedated significant rises in antibody levels against Candida species by 6 to 23 days.     

Allergic bronchopulmonary candidiasis: Case report and suggested diagnostic criteria

A patient with an illness consistent with allergic bronchopulmonary candidiasis is described. The patient had asthma, atelectatic pulmonary infiltrates on three occasions, immediate cutaneous reactivity as low as 10(-7) (wt/vol) to Candida albicans extract, and precipitating antibody to this organism. C. albicans was the only organism cultured from two bronchial lavage specimens. Total serum IgE was elevated to 5745 ng/ml and decreased rapidly with corticosteroid therapy. Serologic studies were not consistent with allergic bronchopulmonary aspergillosis. Serum IgE to C. albicans, measured by ELISA after adsorption of IgG from the serum samples by incubation with staphylococcal protein A, was found to be 575% to 650% above control values. The serum IgE antibody activity against Candida decreased with clinical improvement after corticosteroid therapy.     

Simple and rapid detection of Candida albicans DNA in serum by PCR for diagnosis of invasive candidiasis

A rapid and sensitive PCR assay for the detection of Candida albicans DNA in serum was established. DNA from human serum samples was purified using the QIAamp blood kit, which proved to be a fast and simple method for isolating minute amounts of Candida DNA from clinical specimens for diagnosis of invasive candidiasis. Universal primer sequences used in the PCR assay are derived from the internal transcribed spacer rRNA gene of fungi, whereas the biotinylated hybridization probe used in a DNA enzyme immunoassay (DEIA) binds specifically to C. albicans DNA. The sensitivity of this PCR-DEIA method is very high; the detection limit for genomic Candida DNA is one C. albicans genome per assay. Blood from uninfected and infected persons, ranging from healthy volunteers, patients with mucocutaneous infections, and patients at risk to develop a systemic Candida infection to patients with an established systemic candidiasis, was analyzed for the presence of C. albicans to diagnose fungal infection. Candida DNA could not be detected in sera of 16 culture-negative controls and from 11 nonsystemic candidal infections by PCR or DEIA. Blood cultures from patients at risk were all negative for Candida, whereas all blood cultures from systemic candidiasis patients were positive. However, Candida DNA could be detected by PCR and DEIA in the serum from three out of nine patients who were at risk for a systemic infection and in the serum of all seven patients who had already developed an invasive Candida infection. PCR is more sensitive than blood culture, since some of the patients at risk for invasive yeast infection, whose blood cultures were all negative for Candida, tested positive in the PCR amplification. These results indicate the potential value of PCR for detecting C. albicans in serum samples and for identifying patients at risk for invasive candidiasis.     

Role of calcineurin in stress resistance, morphogenesis, and virulence of a Candida albicans wild-type strain

By generating a calcineurin mutant of the Candida albicans wild-type strain SC5314 with the help of a new recyclable dominant selection marker, we confirmed that calcineurin mediates tolerance to a variety of stress conditions but is not required for the ability of C. albicans to switch to filamentous growth in response to hypha-inducing environmental signals. While calcineurin was essential for virulence of C. albicans in a mouse model of disseminated candidiasis, deletion of CMP1 did not significantly affect virulence during vaginal or pulmonary infection, demonstrating that the requirement for calcineurin for a successful infection depends on the host niche.     

Detection of Candida antigenuria in disseminated candidiasis by immunoblotting.

Immunoblotting (Western blotting) was used to detect Candida albicans antigens in urine of 10 patients with disseminated candidiasis who had two or more positive blood cultures. Twelve urine samples were examined; and antigenuria was found in five of six patients with C. albicans infections, in one patient with a mixed Candida infection (including C. albicans), and in one of two patients with C. tropicalis infection. All except one specimen was collected from 2 to 12 days after initiation of amphotericin B therapy. Positive samples showed different numbers of bands in Western blots with an antigen that had an apparent molecular weight of 47,000 in common. This antigen was not found in the urine of patients who had more than 5 days of therapy for candidiasis and who were responding to therapy. The results suggest that Western blotting for C. albicans antigens in urine may be a useful method for the diagnosis of disseminated candidiasis and for evaluating antifungal treatment.     

Candida in biological human samples

Infections by Candida have been raising in the last decades, and risk factors, mainly immunosuppression and the appearance of Candida no albicans, are determinants in the prognosis of these mycoses. The purpose of this investigation was to identify and establish the prevalence of C. albicans and Candida spp. in candidiases, in patients to the Hospital Universitario de Maracaibo, whose biological samples were processed for both direct examination and cultures, needed for the proper identification. From October 1996 to October 1998, isolation and identification of yeasts of Candida were performed in 177 biological samples: 73 (41.24%) Candida albicans and 104 (58.75%) Candida spp. Both blastoconidias and pseudohyphae were found in 34 samples (19.21%), 24 of which (70.5%) were diagnosed as C. albicans and 10 (29.5%), as Candida spp. Blastoconidias identified by direct method were distributed as C. albicans 34.2% and Candida spp. 65.7%. C. albicans was found more often in intertrigo, sputum and in bronquial lavage samples. Candida spp. was more frequent in nails. Candidiasis is a frequently diagnosed mycosis in hospitals, mainly among immunossuppresed patients. It is very important to use direct microscopical evaluation and cultures, in order to establish the presence of blastoconidias and pseudohyphae, that will help to diagnose the aethiology and prevalence of candidiasis. It is also important to recognize subungueal candidiasis in hospital staff, that could spread the infection to inpatients.     

Role of alveolar macrophages in Candida-induced acute lung injury.

Recent studies have shown that alveolar macrophages (AMs) not only act as phagocytes but also play a central role as potent secretory cells in various lung diseases, including pneumonia and acute respiratory distress syndrome. The behavior of AMs during disseminated candidiasis, however, is insufficiently elucidated. This study is the first to report disseminated candidiasis in AM-depleted mice and to analyze the effect of AMs on Candida-induced acute lung injury. While all AM-sufficient mice died by day 2 after infection with Candida albicans, no mortality was observed among AM-depleted mice. Unexpectedly, the CFU numbers of C. albicans isolated from the lungs of AM-depleted mice were significantly higher than those for C. albicans isolated from AM-sufficient mice. The lung wet-to-dry weight ratio was lower for AM-depleted mice than for AM-sufficient mice, although this difference was not significant. We found that bronchoalveolar lavage fluid (BALF) from AM-depleted mice in candidemia contained fewer neutrophils than BALF from AM-sufficient mice. In addition, myeloperoxidase activities in lung homogenates of AM-depleted mice were significantly lower than those in homogenates of AM-sufficient mice. A significant decrease in levels of murine macrophage inflammatory protein 2 (MIP-2), a potent chemoattractant for neutrophils, was noted in lung homogenates from AM-depleted mice compared with levels in homogenates from AM-sufficient mice. Immunohistochemical studies using anti-MIP-2 antibodies revealed that AMs were the cellular source of MIP-2 within the lung during candidemia. We observed that AM depletion decreased levels of AM-derived neutrophil chemoattractant, alleviated acute lung injury during candidemia, and prolonged the survival of mice in candidemia, even though clearance of C. albicans from the lungs was reduced.     

Diagnosis of invasive candidiasis by a dot immunobinding assay for Candida antigen detection.

A dot immunobinding assay which uses a polyclonal rabbit anti-Candida immunoglobulin G as the primary antibody and colloidal gold coated with goat anti-rabbit immunoglobulin G as the secondary antibody for the detection of Candida cytoplasmic antigens is described. It was able to detect as little as 1 ng of total Candida protein per ml when a cytoplasmic extract of Candida albicans was seeded into buffer and 10 ng/ml when the same extract was seeded into pooled human serum. Serial serum samples from four groups of patients were assayed for Candida antigen: (i) 22 patients with candidemia, (ii) 16 patients at high risk for invasive candidiasis, (iii) 3 patients with other deep mycoses, and (iv) 50 hospitalized patients at low risk for serious Candida infection. Of the 22 candidemic patients, 19 had invasive candidiasis and 3 had transient candidemia. Antigenemia was detected in 16 of the 19 patients with invasive candidiasis (including patients with C. albicans, Candida tropicalis, Candida glabrata, Candida krusei, and Candida parapsilosis) and in 4 of 16 patients at high risk for invasive candidiasis. There was no detectable antigen in 12 high-risk control patients, 3 patients with transient candidemia, 3 patients with other deep mycoses, and 50 relatively low-risk patients. The sensitivity for detecting invasive disease in candidemic patients and specificity for all patients studied were 84.2 and 94.4%, respectively. The positive predictive value was 80%; the negative predictive value was 95.7%. The sensitivity for neutropenic patients with invasive disease was 85.7%. This assay is rapid and accurate and appears to be useful in identifying candidemic patients with invasive candidiasis.     

Epidemiologic study by DNA typing of a Candida albicans outbreak in heroin addicts.

The epidemiology of an outbreak of Candida endophthalmitis in heroin addicts was studied by DNA typing. Although one biotype was prevalent, the 13 isolates of Candida albicans from seven of the patients were placed into six separate groups by DNA type. Thus, the outbreak of candidiasis was not, as had been concluded from biotyping, due to a C. albicans strain of common origin.     

Detection of Candida antigen in sera of patients with candidiasis by an enzyme-linked immunosorbent assay-inhibition technique.

A total of 37 serum samples from 27 cancer patients were tested by an enzyme-linked immunosorbent assay-inhibition technique for the detection of Candida antigen. In 20 randomly chosen sera from patients without clinical evidence of candidiasis and in 10 sera from patients proven by autopsy not to have candidiasis, the inhibition ranged up to 17%; in contrast, inhibition ranged from 22 to 56% in all seven patients proven by autopsy to have systemic candidiasis, indicating the presence of Candida antigen in the sera of these patients. This technique appears promising in diagnosing disseminated candidiasis in cancer patients.     

Increased levels of Candida albicans mannan-specific T-cell-derived antigen binding molecules in patients with invasive candidiasis

In addition to cytokines, CD4+ T cells have been found to secrete soluble, T-cell-derived antigen binding molecules (TABMs). These antigen-specific immunoproteins are thought to have immunoregulatory properties in the suppression of cell-mediated immunity (CMI) because they often associate with interleukin-10 (IL-10) and transforming growth factor beta. Decreased CMI causes susceptibility to infections caused by organisms which are normally nonpathogenic. In this situation, e.g., Candida albicans saprophytism may develop into invasive candidiasis. The difficult diagnosis of invasive candidiasis is based on the findings obtained from blood cultures and with tissue biopsy specimens, with some additional diagnostic value gained by the detection of Candida albicans mannan antigenemia and antimannan antibodies. In the present study, Candida albicans mannan-specific TABM (CAM-TABM) levels in the sera of patients with invasive candidiasis (n = 11), Candida colonization (n = 11) and noncolonization (n = 10), recurrent vulvovaginal candidiasis (n = 30), and atopic eczema dermatitis syndrome (n = 59) and healthy controls (n = 30) were analyzed. For 14 participants, the effect of mannan stimulation on TABM production and gamma interferon (IFN-gamma) and IL-4 mRNA expression by peripheral blood lymphocytes was also studied. It was demonstrated that CAM-TABM production was the highest in patients with invasive candidiasis and that CAM-TABM levels could distinguish Candida-colonized patients from noncolonized patients. In addition, the CAM-TABM level was directly related to mRNA expression for IL-4 but not IFN-gamma. These results reinforce the view that TABMs are associated with decreased CMI, immunoregulation, and the T-helper cell 2-type immune response.     

The relationship between fluorescent, agglutinating, and precipitating antibodies to Candida albicans and their immunoglobulin classes

A parallel study of fluorescent, agglutinating, and precipitating antibodies to Candida albicans revealed that precipitating antibodies belong to the IgG class, whereas agglutinating antibodies reside in the IgG, IgM, and IgA classes. The three types as well as the three classes of antibodies were found in Candida endocarditis and mucocutaneous candidiasis. Immuno-absorption studies suggest that the three serological tests estimate antibodies to mannan determinants of Candida albicans.