Opportunistic yeast infections, with special reference to candidiasis

Etiological Trends and Patterns of Antimicrobial Resistance in Respiratory Infections

BACKGROUND

Respiratory infections are one of the commonest causes of morbidity and mortality related to infectious diseases worldwide. The emergence of antimicrobial resistance is a major global health problem which is well established in developing countries. Good clinical suspicion and correct laboratory identification of respiratory infection causing organisms followed by the appropriate management are needed to compact both community-acquired and nosocomial infection respiratory infections.

OBJECTIVES

A retrospective study was carried out to elucidate the etiology of respiratory infections in Sudan, as well as to guide the physician to the best antimicrobial alternatives used in the treatment of respiratory infection.

METHOD

Respiratory isolates that have been morphologically identified and biologically characterized were subjected to antibiotic susceptibility testing.

RESULTS

A total of 1481 respiratory specimens were examined, recovering 377 organisms from 350 culture positive samples [225(59.7%) sputum, 94(24.9%) broncho-alveolar lavage (BAL), 58(15.4%) Pleural fluid], the commonest organisms were Klebsiella ssp. (25.20%) and mycobacterium tuberculosis (25.20%), followed by Staphylococcus aureus(19.89%) and Pseudomonas aeruginosa(8.49%). High rate of resistance of bacterial isolates was observed to Co-trimoxazole (BA), Ampicillin sulbactam (AS), Cefotaxime (CF) and Tetracycline (TE), being 80%, 72.3%, 68.8% and 66.9% respectively; on the other hand, very low resistance rate was found to Amikacin (AK) and Levofloxacin (LE), being 4.6% and 8.5%, respectively.

CONCLUSION

Guided prescription of antimicrobial agents must be implemented and controlled to limit further spread of antimicrobial resistance.

Case report of invasive, disseminated candidiasis with peripheral nodular cavitary lesions in the lung

We report a case of invasive candidiasis presenting as multiple lung nodules and cavitary lesions with minimal pleural effusion. Candida infections of the lung are rare but can occur after hematologic dissemination of the yeast from other body sites, such as the skin and the gastrointestinal and genitourinary tracts. Here, we describe the case of a 56-year-old female with a history of end-stage renal disease (ESRD) who presented with fever, productive cough, and pulmonary nodules and cavitary lesions seen on a chest computed tomography (CT). The patient's blood cultures were positive for Candida zeylanoides.

Isolated Candida infection of the lung

Candida pneumonia is a rare infection of the lungs, with the majority of cases occurring secondary to hematological dissemination of Candida organisms from a distant site, usually the gastrointestinal tract or skin. We report a case of a 77-year-old male who is life-long smoker with a history of rheumatoid arthritis and polymyalgia rheumatica, but did not take immunosuppressants for those conditions. Here, we present an extremely rare case of isolated pulmonary parenchymal Candida infection in the form pulmonary nodules without evidence of systemic disease which has only been described in a few previous reports.

Photodynamic fungicidal efficacy of hypericin and dimethyl methylene blue against azole-resistant Candida albicans strains

Antimicrobial photodynamic therapy (aPDT) is an emerging alternative to treat infections based on the use of photosensitisers (PSs) and visible light. To investigate the fungicidal effect of PDT against azole-resistant Candida albicans strains using two PSs with a different mechanism of action, hypericin (HYP) and 1,9-dimethyl methylene blue (DMMB), comparing their efficacy and the reactive oxygen species (ROS) species involved in their cytotoxicity. Azole-resistant and the azole-susceptible C. albicans strains were used. Solutions of 0.5 and 4 McFarland inoculum of each Candida strain were treated with different concentrations of each PS, and exposed to two light-emitting diode light fluences (18 and 37 J cm⁻²). Mechanistic insight was gained using several ROS quenchers. The minimal fungicidal concentration of HYP for ≥3 log₁₀ CFU reduction (0.5 McFarland) was 0.62 μmol l⁻¹ for most strains, whereas for DMMB it ranged between 1.25 and 2.5 μmol l⁻¹. Increasing the fluence to 37 J cm⁻² allowed to reduce the DMMB concentration. Higher concentrations of both PSs were required to reach a 6 log₁₀ reduction (4 McFarland). H₂O₂ was the main phototoxic species involved in the fungicidal effect of HYP-aPDT whereas ¹O₂ was more important for DMMB-based treatments. aPDT with either HYP or DMMB is effective in killing of C. albicans strains independent of their azole resistance pattern. HYP was more efficient at low fungal concentration and DMMB at higher concentrations.

Comparison of Albicans ID2 agar plate with the germ tube for presumptive identification of Candida albicans

Albicans ID2 (bioMérieux, France) is a commercially available chromogenic medium that allows rapid and specific macroscopic identification of Candida albicans and facilitates the differentiation of species in mixed cultures. We compared it with the standard method for the identification of yeast species, the germ tube test (GT). This study involved 423 clinical isolates, including 163 C. albicans and 260 non-albicans yeasts. Sensitivity of Albicans ID2 agar plates regarding the identification of C. albicans were 98.2% after 48 h of incubation and specificity of 96.6%. This method using rapid enzymatic method shows the same similar sensitivity than the GT test The false negative rate (1.8%) for the GT test is consistent with that previously reported. None tests discriminated between C. albicans and C. dubliniensis isolates.

Significance of the isolation of Candida species from respiratory samples in critically ill, non-neutropenic patients. An immediate postmortem histologic study

The diagnosis of pulmonary candidiasis is still controversial. We undertook a prospective study on 25 non-neutropenic, mechanically ventilated (> 72 h) patients who died in our ICU with the aim of assessing the incidence and significance of the isolation of Candida species from quantitative cultures of immediate postmortem lung biopsies and different respiratory sampling techniques. Immediate postmortem respiratory samples (endotracheal aspirate, protected specimen brush [PSB], bronchoalveolar lavage [BAL], blind biopsies [average 14/patient], and bilateral bronchoscopically guided biopsies [two per patient]) were taken from all patients. Lung tissue specimens were histologically examined. Respiratory samples were classified as having Candida or otherwise. Ten (40%) patients had at least one pulmonary biopsy yielding Candida spp. Among these 10 patients with Candida isolates, only two had definite pulmonary candidiasis. A total of 470 microorganisms were isolated from 280 of 375 (77%) lung biopsy samples in all 25 patients. Candida species represented 9% (n = 40) of the isolates, corresponding to 10 patients (40%). In the 10 patients in whom Candida species was isolated from pulmonary biopsies, this was always associated with the isolation of the same microorganism from one of the sampling methods. Quantitative cultures of Candida species from different sampling methods correlated well among each other but could not discriminate the presence from absence of Candida pneumonia. A logistic regression model adjusted for the presence of antibiotics, days of antibiotic treatment, mechanical ventilation period, age, ARDS, parenteral nutrition, and gender did not show any independent risk factor for developing positive pulmonary samples for Candida species. The incidence of Candida isolation from pulmonary biopsies in critically ill mechanically ventilated, non-neutropenic patients who die is high (40%). However, the incidence of definite Candida pneumonia was 8%. We also found that Candida colonization is uniform throughout the different lung regions, and that the presence of Candida in respiratory samples, independently of quantitative cultures, is not a good marker of Candida pneumonia in critically ill, non-neutropenic, non-AIDS patients.

Oral candidal infection and denture stomatitis: a comprehensive review

Denture stomatitis rarely occurs without at least one predisposing factor that lowers patient resistance. A new disinfection technique for dentures and oral tissue may eliminate topical or anti-fungal drug use.

In vitro production of tumor necrosis factor by murine splenic macrophages stimulated with mannoprotein constituents of Candida albicans cell wall

Mannoprotein components from Candida albicans were investigated for their ability to induce production of tumor necrosis factor (TNF) by cultured splenocytes from naive or Candida-infected mice. Two chromatographically separated mannoproteins preparations, designated F1 and F2, were as able as the heat-inactivated Candida cells to induce the production of TNF from splenocytes of naive animals. In addition, they caused a significant augmentation of basic TNF secretion by splenocytes of Candida-infected animals. Experiments using plastic and/or nylon wool adherence, as well as treatments with antibodies depleting T or NK cells, consistently indicated that most if not all TNF was produced by splenic macrophages. In cultures of splenocytes from Candida-infected mice, mannoprotein addition also stimulated interferon-gamma (IFN-gamma) production by Thy 1.2 positive cells. Depletion of these cells or addition of anti-IFN-gamma antibodies abolished IFN production and reduced TNF secretion by adherent cells to the levels found in the cultures of mannoprotein-stimulated spleen cells from naive mice. These data add further evidence to the immunomodulatory properties possessed by some cell wall constituents of the human commensal microorganism C. albicans and suggest that IFN-gamma is endowed with a regulatory role in TNF production by mouse macrophages in vitro.

[Isolation, identification and serotyping of Candida albicans from vaginal secretions]

Foram estudadas 104 amostras de secreção vaginal de mulheres com suspeita de candidiase segundo observações clinicas, na cidade de Alfenas-MG. Encontrou-se 55,7% de positividade para Candida albicans .prevalecendo maior índice na raça negra (64% de 25 amostras), sendo de 53,1% (79 amostras), a positividade na raça branca. Em 14 gestantes, a pesquisa da levedura mostrou-se positiva na totalidade dos casos. A maioria das amostras positivas (93,1%) procedia de mulheres com idade compreendida entre 20 40 anos. O uso de anticoncepcionais, antibióticos e presença de displasias cervicais mostraram-se como fatores que contribuiram para maior incidência do fungo. Das 58 amostras de C. albicans isoladas, 50 (86,2%) pertenciam ao sorotipo "A", sendo 37 (74%) isoladas de mulheres da raça branca e 13 (26%) da raça negra. Apenas 08 amostras (13,8%) pertenciam ao sorotipo "B", sendo 05 (11,9%) isoladas a partir de mulheres da raça branca e 03 (18,75%) da raça negra.

Immunomodulation by a low-virulence, agerminative variant of Candida albicans. Further evidence for macrophage activation as one of the effector mechanisms of nonspecific anti-infectious protection

Systemic infection of mice with a Candida albicans strain (PCA-2) incapable of yeast-mycelial conversion is known to activate host macrophages and confer protection against subsequent challenge with highly pathogenic cells of the same species or by other micro-organisms. In an attempt to define the relative contributions of different immune components to the protection mediated by PCA-2, we evaluated the effect of manipulations known to selectively deplete immune functions. By means of cytostatic drug or silica induced toxicity, it was possible to demonstrate that no crucial role in protection is played by cytotoxic T lymphocytes or B cells, nor by PCA-2 induced granulocytosis alone. The cells responsible for this effect were dacarbazine-resistant silica-sensitive macrophages whose activity in vivo paralleled the in vitro expression of splenic candidacidal activity. Macrophage activation by PCA-2 and increased anti-Candida resistance did not result from an immunological response mediated by T-dependent effectors, as these effects could be reproduced in athymic mice.

Umbelliferyl-labeled galactosaminide as an aid in identification of Candida albicans

The initial evaluation of a fluorescence, nonmicroscopic method of rapid identification of Candida albicans is described. A total of 524 yeast isolates were evaluated in parallel by the umbelliferyl-conjugated N-acetyl-beta-D-galactosaminide (UAG) test and the germ tube (GT) test in comparison with the API 20C Yeast Identification System. The UAG test correctly identified 333 of the 334 isolates of C. albicans (99.7%), and the GT test identified 328 (98%). There were three false-positive GT reactions and five false-positive UAG reactions with 69 isolates of C. tropicalis. The sensitivity and specificity were 99 and 97%, respectively, for the UAG test and were both 98% for the GT test. The UAG test requires less than 2 h for test completion compared with 2 to 4 h for the GT test, is similar in cost, has a nonmicroscopic visual endpoint, and eliminates the health hazards of handling pooled human sera.

Rapid identification of yeasts by semi-automated and conventional methods

Five different methods for the identification of significant yeast from clinical specimens were compared for their reliability, rapidity and cost-effectiveness. Three commercial methods consisted of semi-automated Abbott's yeasts identification system using MS-2 (Abbott Laboratories, Diagnostic Division, Irving, Texas), API 20C (Analytab Products, Inc., Plainview, NY) and Uni-Yeast-Tek (Flow Labs, Inc., MacLean, VA). Two conventional methods included the modified dye-plur plate auxanographic and rapid tube assimilation method. The 242 coded clinical isolates used in this study included 20 species of Candida, Cryptococcus, Saccharomyces Geotrichum, Rhodotorula, Torulopsis and Trichosporon. The identification accuracies with all the systems ranges between 92.3% to 97.5%. Results were available with Abbott's MS-2 within 24 h, with rapid tube assimilation method in 6-48 h and in 72 h with other systems. Rapid tube assimilation and dye-pour-plate auxanographic methods were least expensive, with labour and material costing around $1.00 per identification, whereas the commercial system cost a little over $5.00.

Candida berkhout species isolated from deep-seated and superficial candidosis. Classification of species with the N. van Uden and H. Buckley key

The purpose of the present paper is to improve the understanding of the incidence of Candidosis in human infections. 85 species of Candida isolated from deep-seated and superficial Candidosis were studied. Identification was attained using the key of N. van Uden & H. Buckley (22).

In vitro determination of phagocytic indices of Candida berkhout species by rat peritoneal macrophages

The aims of this investigation were to study and describe the behaviour of 13 different species of Candida, as compared with C. albicans, by means of phagocytosis assays in vitro. Tests were carried out with rat peritoneal macrophages in contact with quantified suspensions of live yeasts. Phagocytic indices, candidacidal activity and filamentation rat were tested microscopically after 3 h incubation at 37 degrees C. The phagocytic indices obtained allowed us to separate the fungi into four groups. Candida albicans and tropicalis belong to Group I; diddensii and shehatae, among others, belong to Group II; sake, krusei, viswanathii, etc., Group III; and C. glaebosa and haploid strains of Pichia ohmeri (C. guilliermondii var. membranaefaciens), Group IV. These data would suggest a possible correlation between pathogenesis and phagocytic indices. There were no evidences of any phagocytes ability to kill yeasts. Candidacidal activity was absent in the species assayed. Yeast lysis may have been observed if our assays would have taken longer than 3 h.

Evaluation of nystatin in prevention and elimination of oropharyngeal Candida in immunosuppressed patients

Thirty-three patients with acute leukemia or lymphoma received an ongoing topical treatment with an oral suspension of nystatin during prolonged periods of intensive chemotherapy and severe granulocytopenia. The preparation proved ineffective in eliminating colonized Candida species from the oropharynx in ten of eleven patients at the time of admission and was of questionable value in preventing later colonization in others. The difficulties surrounding the identification of systemic candidiasis, its significance in the immunosuppressed patient, and the role of topical antifungal prophylaxis are discussed.

Bacterial-mycotic liver abscess in a non-immunocompromised host

We are presenting the case of a 70-year-old, formerly healthy patient. Seven weeks after abdominal surgery, a liver abscess was diagnosed by sonography and aspiration. Cultures revealed a mixed bacterial-fungal etiology. Treatment with irrigation (povidone iodine) and parenteral mezlocillin failed. Final cure was only achieved when long-term treatment with piperacillin and miconazole was initiated and abscess drainage removed.

Oral mucosal complications in cancer chemotherapy

Complications involving the oropharyngeal mucosa occur commonly in patients receiving chemotherapy for cancer. This communication presents a classification and description of the principal changes encountered, and suggests guidelines for their management.

The spectrum of hepatic candidiasis

The liver is affected in up 50 to 75% of compromised hosts with disseminated Candida albicans infection who come to autopsy. The antemortem diagnosis of hepatic candidiasis is rarely made. Blood cultures are negative in approximately 50% of cases, and biochemical parameters of hepatic injury may be of nonspecific value. Additionally, the more commonly seen renal, cardiac, and respiratory involvement may overshadow the hepatic lesion. In a review of 17 autopsy series of disseminated candidiasis, 92 cases with hepatic involvement were identified for a mean prevalence of 13.7%. Hepatic granulomas and microabscesses were the two most common histological lesions attributable to Candida. Inflammatory aggregates, centrilobular congestion, bile stasis, and fatty change were seen less frequently. The diagnosis should be suspected in any compromised host with unexplained fever with or without elevated alkaline phosphatase or bilirubin levels. The diagnosis can be made by percutaneous needle biopsy or at laparoscopy in a majority of cases. Early treatment with Amphotericin is associated with prolonged survival.

Systemic infection with Trichosporon cutaneum in a patient with acute leukemia: report of a case

A case of disseminated infection with Trichosporon cutaneum, a fungus that causes white piedra, is described. The patient, a 58-year-old barber with acute leukemia, had fever, myalgias and skin lesions. He was receiving cytotoxic drug therapy and prednisone, was severely neutropenic and was being treated with broad spectrum antibiotics. Blood cultures and a biopsy of the skin lesion grew T. cutaneum. He died despite amphotericin B therapy. At autopsy, widespread infection with T. cutaneum was present. T. cutaneum is another fungus capable of causing widespread systemic disease in the immunocompromised host.

Pathogenicity of some ordinarily harmless yeasts for cortisone-treated mice

The pathogenicity for normal and cortisone-treated mice of Candida requinyii, Pichia etchellsii, Candida famata (Torulopsis candida) Trichosporon cutaneum and Sterigmatomyces aphidis, isolated from foodstuffs or clinical material, is reported. The test species proved nonpathogenic to normal mice inoculated intravenously with up to 10(7) cells. There was neither any mortality nor gross or microscopic lesions, and cultures were negative from the visceral organs and brain when these animals were necropsied after 3 weeks of observation. In cortisone-treated mice, on the other hand, the yeasts caused mortalities, the extent of which varied according to the infecting species and the challenge dose. Candida requinyii was the most pathogenic species, causing 100% mortality in 8 days, followed by S. aphidis, C. famata, T. cutaneum and P. etchellsii which killed 75%, 50%, 38% and 25% of the infected animals. Apart from the higher mortalities, C. requinyii and S. aphidis caused more frequent visceral lesions than did either T. cutaneum or C. famata. Involvement of the brain occurred more commonly with C. requinyii and T. cutaneum than with C. famata or S. aphidis. P. etchellsii was the only yeast that failed to incite any gross or microscopic lesions. The study re-emphasizes the pathogenic potential of ordinarily harmless fungi for immunosuppressed hosts.

Candidiasis: detection by gas-liquid chromatography of D-arabinitol, a fungal metabolite, in human serum

D-Arabinitol was identified as a major metabolite of Candida species in human subjects. Gas-liquid chromatography was used to measure the concentration of D-arabinitol in serum. The study included subjects who were healthy and cancer patients who had proven invasive candidiasis or were colonized with Candida. D-Arabinitol concentrations greater than 1.0 microgram per milliliter were found in serum from patients with invasive infection. This technique may prove valuable in the diagnosis of invasive candidiasis.

Miconazole therapy for systemic candidiasis in a conjoined (Siamese) twin and a premature newborn

A 2.5 kg thoracopagus (Siamese) twin and a 0.73 kg premature newborn developed systemic candidiasis and were treated with intravenous miconazole. The conjoined twin was in a state of severe metabolic acidosis, respiratory distress, jaundice, anuria, abdominal distension, and shock. The 0.73 kg premature infant was also in a state of severe metabolic acidosis, respiratory distress, and oliguria. Miconazole was used in this desperate situation for the treatment of life-threatening candidiasis. Both infants responded well to treatment and recovered. All parameters of their diseases improved during therapy despite pre-existing multiple organ dysfunction. Miconazole can be a safe alternative to amphotericin B for the treatment of systemic candidiasis in neonatal infants, including those with impaired renal function.

Relationship of oral complications to peripheral blood leukocyte and platelet counts in patients receiving cancer chemotherapy

Patients undergoing cancer chemotherapy often suffer from oral complications as a result of their disease and its treatment. The effects of the chemotherapy on the bone marrow and oral mucosa, coupled with the patient's immunosuppressed state and altered oral microbial flora, predispose these patients to oral mucositis, infection, and hemorrhage. The oral mucosa appears to mirror the effects of the chemotherapy on the bone marrow, as there appears to be a direct relationship between the changing peripheral blood counts and the status of the oral mucosa.

Evaluation of a modified dye pour-plate auxanographic method for the rapid identification of clinically significant yeasts. Comparison with two commercial systems

A modified dye pour-plate auxanographic (DPPA) method for the presumptive identification of medically important yeasts was evaluated, in a comparative study with a conventional procedure, the API 20C clinical yeast system (Analytab Products Inc.), and the Uni-Yeast-Tek (UYT) system. The 174 coded clinical isolates were members of the genera Candida, Cryptococcus, Rhodotorula, Saccharomyces, Torulopsis, and Trichosporon. The identification accuracies with DPPA, API, and UYT were 95%, 93%, and 99% respectively. DPPA and API required more time to inoculate but gave rapid identification profiles. UYT was simple to inoculate and both UYT and DPPA were easy to read. Cost analysis of the three rapid methods demonstrated DPPA to be the most economical making it a feasible alternative for small clinical laboratories as well as large laboratories possessing the facilities to make their own media.

Clinical evaluation of oral Candida in cancer chemotherapy patients

No overt clinical oral candidiasis was noted upon either direct oral examination or review of medical records. No significant change in percent of Candida species as compared to other populations is seen in this study. Varying percents of individual species do differ from other reports. Alimentary and digestive tract tumors represented over 56% of the primary malignancies. There was a significant correlation between decrease in salivary pH and increase in percent of Candida species growth. Most significantly, however, the preliminary data in this study might eventually contribute to continuing investigation of Candida species in human cancer patients.

Oral mycoses and their treatment

Mycoses of the mouth and nearby areas can be caused by both yeasts and filamentous fungi. They may appear either independently or as part of a systemic infection. It is typical of many mycoses that they occur as a consequence of local factors operating in the mouth, or in patients debilitated by severe diseases. Yeasts that are part of the normal microbial flora of man, among them especially Candida species, are the most frequent causative agents. Some tropical or semitropical infections may occur in Scandinavia and Finland, but they are rare. Local therapy with antimycotics is often effective in acute infections, whereas some chronic ones may make systemic administration necessary. Some of these infections are treated surgically.

Oral candidosis--frequency, treatment and relapse tendency in a group of psychiatric inpatients

Candida fungi are frequent in the oral cavity, especially in denture wearers. The infection can cause serious complications in elderly or debilitated subject. The present experimental group consisted of 81 female psychiatric patients (35--91 years of age). In addition to a clinical examination, smears from the palate, tongue and dentures (when present) were cultured on Nickerson's medium. Patients with a positive clinical and/or microbiological diagnosis were treated for 35 days with one of two gels containing 1% chlorhexidine. Following the treatment period patients with full or partial dentures took part in a maintenance program, in which the dentures were either soaked in a 0.2% chlorhexidine solution or mechanically cleaned every day for a period of 35 days. Two thirds of the patients showed clinical signs of oral candidosis or had positive cultures preexperimentally. The treatment with chlorhexidine gels resulted in negative cultures in 71% and negative clinical diagnosis gels resulted in negative cultures in 71% and negative clinical diagnosis in 96% of the patients. Mucosal soreness occurred during the treatment period in 8 out of 28 patients wearing full dentures. Xerostomia was not influenced by the chlorhexidine treatment. The relapse tendency was low during the post-treatment period. No clearcut differences between the two maintenance methods could be detected.

Hospital-associated candiduria: predisposing factors and review of the literature

A series is presented of 98 patients with hospital-acquired candiduria identified by continual nosocomial infection surveillance. Analysis of the differences between case-matched controls and 20 patients indicated that there were significant increases in the duration of prior Foley catheterization (12 versus 6 days), length of time on multiple antibiotics (16 versus 7 days) and length of total hospitalization of the infected group. Review of the infected patients' charts showed that the indications for bladder catheterization and use of antibiotics were usually explicitly stated and considered valid. The English literature on primary Candida urinary tract infections is reviewed and future approaches to the problem are summarized.

Pulmonary disease caused by Candida species

Candida species are often found in sputum specimens. Their role as a possible cause of pulmonary disease is a frequent consideration, particularly in patients receiving immunosuppressive or long-standing antimicrobial therapy. At Memorial Hospital and New York Hospital, 30 patients with histologic evidence of Candida pulmonary infection were identified over a two year period. These infections reached the lungs by hematogenous spread in 10 patients and by aspiration in 16 patients. Most the patients had malignant neoplastic disease. The Candida pulmonary disease appeared to be significant clinical factor in only three cases. Experience from our institutions and from the literature indicates that Candida species rarely cause significant pulmonary disease. When such involvement is extensive, the patient is usually terminally ill from multiple other factors.

Oral anticandidal prophylaxis in patients undergoing chemotherapy for acut- leukemia

Fifty-six untreated patients with acute leukemia (38 acute myelogenous leukemia, 16 acute lymphoblastic leukemia, and 2 blast crisis of chronic granulocytic leukemia) were randomized on admission to one of three groups--one to receive oral anticandidal prophylaxis through the period of remission induction chemotherapy with nystatin, another to receive natamycin, and the third to receive no anticandidal prophylaxis. Neither of the first two groups show any advantage over the last and it is concluded that provided gut sterilization regimes are not employed, prophylactic oral anticandidal treatment is of no value in these patients and should be reserved until there is clinical evidence of infection.

Candida peritonitis. Report of 22 cases and review of the English literature

Thirty-one patients with Candida isolated from peritoneal fluid were examined. Twenty-two were considered to have Candida peritonitis. The data on these 22 patients, plus 12 additional patients described in the literature, were reviewed. This infection was observed as a complication of peritoneal dialysis, gastrointestinal surgery or perforation of an abdominal viscus. Recent antibiotic administration seemed to be an important predisposing factor. The disease usually remained localized intra-abdominally, although disseminated candidiasis was also noted in three cases. Clinically significant infection could be differentiated from peritoneal contamination with Candida by the presence and persistence of fever, peritoneal signs, peripheral leukocytosis, positive peritoneal cultures for Candida, abnormal films of the abdomen and purulent ascitic fluid. Surgical interventions and removal of infected peritoneal fluid were the cornerstones of therapy. Short-term, low-dose systemic and/or intraperitoneally administered amphotericin B appeared promising in the treatment of unremitting infection. Mortality in treated patients was low and was comparable to that in patients with bacterial peritonitis.

Yeast colonization in hospitalized and nonhospitalized children

Data have been accumulated to determine the prevalence of yeast colonization of the skin and digestive tract of hospitalized and nonhospitalized infants and children. There was no difference in the prevalence between hospitalized patients at the time of admission and nonhospitalized children. However, there was a positive correlation of the duration of hospitalization and the prevalence of yeast colonization. There were no correlations of hospitalization with site of colonization, age of the patient, or type of yeast isolated.

Improved auxanographic method for yeast assimilations: a comparison with other approaches

An improved pour-plate auxanographic method has been developed for determining the assimilation of 14 different carbohydrates by medically important yeasts. Reduction of a dye incorporated into the agar has been correlated with the growth and carbohydrate assimilation of the yeasts, allowing the speciation of many yeasts within 24 to 48 h. This technique has been found to compare more than favorably with existing yeast assimilation techniques, in terms of rapid identification, total cost, and technician time in preparing and inoculating the plates. The dye pour-plate auxanographic technique provides an easier-to-interpret, rapid, and reproducible method of mycological identification for small clinical laboratories.

An amino acid liquid synthetic medium for the development of mycelial and yeast forms of Candida Albicans

A chemically defined medium composed of 6 amino acids, biotin, inorganic salts and glucose for the growth of yeast and mycelial phases of Candida albicans at 25 degrees C and 37 degrees of C respectively was developed based on the aminopeptidase(s) profile of the fungus. This medium has proved successful in maintaining the growth characteristics of both phases during serial transfers. The relative pathogenicity, virulence, invasiveness and immunogenicity of the yeast and mycelial phases are discussed.

Factors affecting filamentation in Candida albicans: relationship of the uptake and distribution of proline to morphogenesis

When glucose was present in high concentration, Candida albicans formed filaments in a phosphate-buffered medium, regardless of the nitrogen source. In lower concentrations of glucose, filamentation occurred only when various members of the glutamate, succinyl, or acetoacetyl-coenzyme A families of amino acids were used as sole nitrogen sources. Yeast morphology could be maintained either by replacing the amino acids in the medium with ammonium chloride or by making the medium high in phosphate or biotin. Studies using [U-14C]proline indicated that proline was catabolized in a manner consistent with the generation of increased cellular reducing potential and that the proline label entered into the Kreb's cycle. A reduction in Kreb's cycle activity was evidenced by an initial increase and then a rapid drop of the total organic acid content of the cells as well as in specific Kreb's cycle intermediates. Filamentation under conditions of low phosphate, high glucose, and increased cellular reduction potential, accompanied by a decrease in Kreb's cycle activity, suggests that morphogenesis in C. albicans is correlated with a Crabtree-like effect, i.e., repression of mitochondrial activity.

Surgical treatment of Candida endocarditis

Case reports from a group of 15 patients with Candida endocarditis seen and treated at the Los Angeles-University of Southern California Medical Center between 1960 and 1974, together with a survey of other reported cases, serve to re-emphasize the importance of early diagnosis of this disease and lead to certain conclusions regarding its treatment. With medical or surgical treatment alone, the mortality for Candida endocarditis is 82 per cent. With surgery and medical treatment combined, the mortality is 20 percent. It is important to institute medical treatment as soon as diagnosis of Candida endocarditis is made and surgery must be performed as soon as possible, preferably within 24 to 48 hours or, at most, a few days after the patient has left the hospital. Close observation of the patient after discharge is important.

Fungal septicemia in surgical patients

Opportunistic systemic fungal infections are more frequent than generally realized. Increased awareness and a high index of suspicion of fungal super-infection in the presence of sepsis is required to bring about recognition and therapy. The intravenous catheter is an important portal of entry or may act as a foreign body favoring localization of a septic process. In its presence, fungemia must be guarded against. Whenever an intravenous catheter is removed, its tip should be cultured. Removal alone may be a critical item in therapy. In febrile patients, in whom the course of fever is not established, frequent blood cultures with attention directed specifically at fungi should be obtained. Fungi are not easily isolated and identified and only by requesting special attention from the microbiologist can the diagnosis be established in the average institutional laboratory in time to permit appropriate therapy. Since available therapeutic measures are strikingly effective when instituted early, awareness and alertness on the part of the clinician constitute the key to cure.

Assessment of germ tube dispersion activity of serum from experimental candidiasis: a new procedure for serodiagnosis

Germ tubes of Candida albicans and C. stellatoidea clump in normal serum but disperse in serum from animals infected with either species of Candida. A new procedure for the assessment of grades of germ tube dispersion activity of serum is presented; this procedure is to count the number of freely dispersed germ tubes in test serum into which a definite number of yeast-type C. albicans has been inoculated. The relationship between the serum activity and macroscopic lesions caused by candidal infection is observed, indicating the possibility of applying the phenomenon to the serodiagnosis of deep-seated candidiasis. The specificity and sensitivity of the test are also examined.