Disseminated histoplasmosis by Histoplasma capsulatum var. duboisii in a paediatric patient from the Chad Republic, Africa

Histoplasmosis caused by Histoplasma capsulatum var. duboisii is an endemic mycosis of sub-Saharan Africa that usually affects the skin, subcutaneous tissue, lymph nodes and bones. We present a case of a 10-year-old immunocompetent girl with severe cutaneous and subcutaneous abscesses affecting the head and upper body. Microscopic examination showed polar budding yeasts and short mycelium compatible with H. capsulatum var. duboisii. Cultures were not possible but serology showed antibodies against both H. capsulatum var. duboisii and H. capsulatum var. capsulatum antigens. Presumptive diagnosis of histoplasmosis was done but treatment with itraconazole was inefficacious. After 15 days of treatment with Amphotericin B i/v, improvement was evident and, three months later, the patient was discharged with only residual lesions. Seven months later, no relapses were observed.

Seasonal distribution of Alternaria, Aspergillus, Cladosporium and Penicillium species isolated in homes of fungal allergic patients

BACKGROUND

Allergy to airborne fungi can cause rhinitis and severe asthma, hence the exposure to spores inside home is an important factor of sensitization. The aim of this study was to determine the distribution and prevalence of species of Alternaria, Aspergillus, Cladosporium and Penicillium inside and outside of homes of patients allergic to fungi and to evaluate seasonal variations.

METHODS

Air samples were collected in 22 selected homes of patients with allergy to fungi using a volumetric method of impacting plates with culture media. The isolated species were identified and statistical analysis of the presence of the four fungi was carried out.

RESULTS

A total of 431 indoor and 150 outdoor exposed plates were cultured, leading to isolation of 11,843 colonies of fungi (range 0- 1 666 colony-forming units per cubic meter (CFUs/m(3)). 85.5% of total colonies belonged to the four genera considered. The highest presence of Aspergillus, Cladosporium and Penicillium in indoor environment was registered in autumn. Alternaria was more frequent in summer. In the outdoor environment, Penicillium was more abundant in winter and Aspergillus in summer (P= .002). The largest numbers of isolations were of Cladosporium and Penicillium during all four seasons, indoors as well as outdoors. Alternaria was present in all the homes studied both in summer and in autumn. The most prevalent species were: Alternaria alternata, Cladosporium herbarum, Cladosporium cladosporioides, Aspergillus niger and Penicillium chrysogenum.

CONCLUSIONS

The quantitative analysis of the four taxa related with respiratory allergies demonstrated considerable seasonal variability. Statistical differences between the indoor and outdoor prevalence were detected only in Alternaria. In summer and autumn, the greater level of exposure to the four studied taxas occurred inside homes.

Early diagnosis of candidiasis in non-neutropenic critically ill patients

OBJECTIVE

To determine a method for the early diagnosis of candidiasis in non-neutropenic critically ill patients in order to reduce mortality.

METHODS

A prospective study in non-neutropenic critically patients in whom Candida spp. were detected, was made in an intensive care unit (ICU) during an 8-year period from 3389 patients admitted. A diagnostic and therapeutic protocol was designed. Invasive candidiasis was defined according to dissemination and multifocality.

RESULTS

Candida spp. were found in 145 cases (4.3%): 120 (83%) were considered as invasive candidiasis and 25 as colonisation (17%). The hospital mortality was 46% (67/145). A post-mortem study was carried out in 54% (36/67) of hospital deaths. Candida albicans was the most frequently isolated species (87%), followed by Candida glabrata (18%). There were 24 candidemias and three cases of endophtalmitis. Digestive and respiratory samples and non-C. albicans yeasts were risk factors for invasive candidiasis. The mortality rate was related statistically to invasive candidiasis and inversely to the appropriate antifungal treatment.

CONCLUSIONS

Invasive candidiasis is related to digestive and respiratory samples and to the presence of non-C. albicans species. A simpler definition of invasive candidiasis in non-neutropenic critically ill patients will permit more rapid and accurate specific antifungal therapy.

Pathogenicity of Cryptococcus neoformans var. gattii in an immunocompetent mouse model

The pathogenicity of two different genomic profiles of Cryptococcus neoformans var. gattii serotype B isolated from goats that died from cryptococcal pneumonia was assessed in an experimental model of immunocompetent mice. One strain of each randomly amplified polymorphic DNA (RAPD) profile (GR52 and GR56) and three reference C. neoformans isolates representing serotypes B, D and C were used. BALB/c male mice were inoculated by the intraperitoneal route with each strain. After 4 weeks of follow-up, the animals were sacrificed and autopsy specimens of testes, liver, spleen, kidney, lungs and brain were cultured and stained for histopathology. Although spontaneous mortality was only 2% (one animal), all mice except for those inoculated with serotype C showed positive cultures in almost one organ. The strain GR52 isolated from goat showed the highest rate of positive cultures (80%) followed by serotype D (77%). Serotype B reference strain and second goat strain GR56 were both isolated from 70% of samples. Serotype C was recovered in only 33% of organs, and never from brain or lung specimens. GR52 grew abundantly from all lung cultures, and yeast cells with large capsules were seen in histopathology inside the alveoli, peribronchial vessels and interalveolar spaces. They appeared to elicit no inflammatory response. We conclude that intraperitoneally inoculated C. neoformans var. gattii shows high virulence in this immunocompetent mouse model. Strain GR52 was highest in pathogenicity and had marked lung tropism. In contrast, the serotype C reference strain showed the lowest pathogenicity and seemed not to spread outside the abdominal viscera.

Aspergilosis pulmonar. Papel de los corticoides como factor de riesgo asociado en el bronquítico crónico

BASIS

Description of a situation of incidence increase of bronchial secretions with positive cultures for Aspergillus fumigatus, and analysis of the related risk factors in the invasive aspergillosis.

METHODS

Between January 1999 and February 2000, a prospective study of the patients was conducted with culture of bronchial secretions and with positive result for A. fumigatus.

VARIABLES STUDIED

age, sex, primary diagnosis, type of cultivated sample, clinical interpretation (colonization/infection), probable source (community/nosocomial), situation of the patient after discharge, and risk factors for opportunistic infection. The results were compared among the colonized and infected patients.

RESULTS

Fifty-two patients showed positive cultures of bronchial secretions to A. fumigatus, 43 (82.6%) colonized and 9 (17.3%) infected. Cultivated sputum sample on 30 occasions (57.6%) and bronchial aspiration in 22 (42.3%). Median age: 70 years (31-84). Sex: 40 men (76.9%). Probable source of infection/colonization: nosocomial in 18 cases (34.6%), community in 3 (5.7%) and unknown in 31 (59.6%). Mortality: 15 patient colonized (34.8%) and 8 infected (88.8%). Risk factors with statistical significance for invasive infection by A. fumigatus: diagnosis of chronic bronchopathy (COPD) (p=0.007) and treatment with prednisone in dose higher than 60 mg/day (p=0.0005).

CONCLUSIONS

The patients with positive culture of bronchial secretions to A. fumigatus with COPD and treatment with prednisone in dose higher than 60 mg/day should be considered with a greater risk for infection by this pathogen. A more restricted use and adequate of the corticoids in these patients, and an early diagnosis and treatment in light of the suspicion of infection by A. fumigatus in patients with COPD, it could imply a reduction of morbidity and mortality.

In vitro susceptibility of Cryptococcus neoformans serotypes to GM 237354 derivative of the sordarin class

In vitro susceptibility to the sordarin derivative GM 237354 and amphotericin B were tested in a total of 190 Cryptococcus neoformans clinical isolates from different geographical areas of Spain and South American countries. Minimal inhibitory concentrations (MICs) were obtained using the NCCLS reference microbroth dilution method and analysed according the serotypes of Cr. neoformans. The MICs for amphotericin B were lower than 1.0 microg ml(-1) (MIC90% 0.5 microg ml(-1) , MIC50% 0.125 microg ml(-1)) but five isolates showed MICs of 2.0 microg ml(-1) to GM 237354 (MIC90% 1.0 microg ml(-1), MIC50% 0.5 microg ml(-1)). Cryptococcus neoformans var. gattii serotype B, was significantly less susceptible than A and AD serotypes (P = 0.047 and P = 0.022, respectively).

[Epidemiological study of cryptococcosis in Spain: first results]

The study constitutes an approach to the knowledge of the epidemiology of cryptococosis in Spain. For detection of cases 167 Spanish hospitals were contacted. All cases included were accompanied by the correspondent isolate of Cryptococcus neoformans, together with clinical, demographic and mycological data. Results obtained from January 1998 to end of December 1999 are analysed and presented here. Fifty-six Spanish hospitals reported 58 cases of cryptococcosis; only 43 of them were adequately documented and accompanied by the clinical isolate. The results showed a higher incidence in males (88.4%) than in females (11.6%); being most frequently affected those between 30 and 40 years old (48.8%). The 84.6% (33) corresponded to new cases and 15.4% (6) to relapses of the disease. The HIV infection was the most frequent risk factor reported (86%) and, for 29.7% (11) of them, cryptococcosis was the AIDS defining disease. For the diagnosis, CSF analysis showed the best results (India ink; culture and antigen detection). All strains collected (100%) corresponded to C. neoformans variety neoformans. Serotypes distribution was 45.5% for serotype A and 22.7% for each of serotypes D and AD.

The utility of serology in diagnosing candidosis in non-neutropenic critically ill patients

This study was carried out to evaluate the utility of serological tests in the diagnosis of candidal infections in non-neutropenic critically ill patients. A prospective study was carried out in a 10-bed general intensive care unit; all patients with at least one organic sample with Candida spp. were included. A therapeutic-diagnostic algorithm was designed, and patients were treated or not, according to a classification. Blood samples were taken, and serological tests included: antigenaemia detection using two different commercial latex kits (Cand-Tec and Pastorex) and antibody detection by indirect haemagglutination (IHA) and indirect germ tube immunofluorescence (IFA). A total of 56% of antibody tests (IHA 45% and IFA 64%) and 26% of antigen tests (Cand-Tec 36% and Pastorex 17%) were positive. The sensitivity and specificity of these tests with respect to systemic candidosis were 37% and 78%, respectively, for antibodies, and 0% and 90% for antigens. There was statistical significance for mortality and low levels of antibodies; Candida glabrata was detected by IFA and Candida tropicalis by Cand-Tec. Serological tests may help to define the prognosis of these patients and to support the detection of specific Candida species.

Antifungal compounds: controversies, queries and conclusions

A new session in this Congress was the development of a discussion panel regarding controversies and queries about the main topics of treatment and prophylaxis of severe systemic mycoses. Experts presenting each side of three controversial areas provided an interchange of ideas and clarified those areas where there remain substantial disagreements. Some common recommendations have been made, and some differences persist. The contents of this session are compiled in this paper. Due to the limitations of space, this paper presents the most relevant parts of each presentation. The large and up-to-date list of references should be useful to gain a better understanding of these subjects.

[In vitro antifungal susceptibility of dematiaceous filamentous fungi using the E-test]

The usefulness of the E-test((R) )has been studied to determine the in vitro susceptibility of 52 isolates of 17 species to five antifungal drugs: amphotericin B, 5-flucytosine, ketoconazole, itraconazole and fluconazole. Minimal inhibitory concentrations were determined following the manufacturers' instructions, except in the preparation of the inoculum. In this case a spectrophotometric method was used to obtain 1-5 ' 10(6) CFU/ml. Two different culture media were included: casitone-agar and RPMI 1640 agar. Most isolates showed clear growth in both media after 96 h of incubation at 37 degrees C. The species showed low MIC concentrations to ketoconazole and itraconazole. Only 55.8% of isolates showed MICs </= 2 mg/l to amphotericin B and 98% of strains presented MICs of 32 mg/l for 5-flucytosine. With the exception of one isolate, the remaining were resistant to fluconazole with MIC values 256 mg/l. No differences were found between the MICs for the two media, but values were easier to read in casitone-agar. These results suggest that itraconazole and ketoconazole should be the antifungals of first choice for treating infections due to the evaluated species. This study showed that the E-test((R) )appears to be a suitable method for testing the susceptibility of dematiaceous filamentous fungi to antifungals.

Successful treatment with liposomal amphotericin B of an intraabdomianl abscess due to Candida norvegensis associated with a Gore-Tex mesh infection

There are few reports of severe infections caused by Candida norvegensis. We here describe a case of C. norvegensis-associated intraabdominal abscess and Gore-Tex mesh-associated infection, successfully treated with liposomal amphotericin B and removal of the mesh. This is, to our knowledge, the first report of C. norvegensis causing this type of infection.

Changes in androgenic steroid profile due to urine contamination by microorganisms: a prospective study in the context of doping control

Urine contamination by microorganisms may affect the interpretation of urinalysis in different areas of clinical diagnosis. This is particularly relevant in doping control. A prospective study was designed to assess the effects of urine contamination by selected pathogens on the endogenous androgenic steroid profile. Pooled urine from a healthy male volunteer with standard steroid profile compared with reference values for the Caucasian population was sterilized by filtration and stored in sterile glass tubes. Aliquots were inoculated with known amounts of 15 different organisms (bacteria, fungi, and moulds) and incubated at 37 degrees C for 2 weeks. Different markers of urine contamination, such as pH, deconjugation of steroids, and metabolic by-products, were determined. Alkalization of urinary pH was not a reliable indicator of urine contamination as several organisms grew in this medium and no alteration of this parameter was found. In uncontaminated urine, less than 10% of steroid glucuronide conjugates were spontaneously hydrolyzed. Higher rates of hydrolysis for sulfate conjugates were found. An unconjugated fraction higher than 10% of the total amount of testosterone was a reliable indicator of urine contamination. However, microbial production of testosterone or epitestosterone was not detected. In contrast, a few organisms were able to synthesize 5alpha-androstanedione, 5beta-androstanedione, and androstenedione using endogenous steroids as substrates.

[Diagnostic usefulness of the intradermal test with histoplamin in non-endemic areas of histoplasmosis]

The histoplasmosis in Spain is an imported disease presenting in most of case diagnostic difficulties. In this paper, the intradermal skin test with Histoplasma capsulatum antigen as diagnostic method in immunocompetent patients with clinical and radiological signs compatible with histoplasmosis after being visited Central and South American endemic counties, in which this mycosis is endemic. Nine Spanish patients coming from different countries of Latin America with fever and acute respiratory symptoms compatible with histoplasmosis were studied. Other nine accompanying subjects and five controls were also evaluated. Patients underwent mycological cultures and and serological tests for H. capsulatum. Intradermal test with 1% histoplasmine were done in all patients. Serology and skin tests tests were also performed in accompanying people. Intradermal were done in healthy controls. Skin test with histoplasmine were positive in seven of the nine patients. Six of these showed precipitating antibodies against the same antigen. H. capsulatum was only isolated from bone marrow biopsy samples in one patient. The seven patients were given itraconazole by oral route and all symptoms improved after 2 and 4 weeks. In five accompanying subjects the skin test were also positive so that a subclinical histoplasmosis was diagnosed. In the remaining patients and healthy accompanying subjects histoplasmosis infection was excluded. In non endemic geographical areas of histoplasmosis intradermal skin test with histoplasmin when used in immunocompetent individuals is an easy and reliable method for the diagnosis of this mycosis as well as for epidemiological studies.

Antigens of Fusarium solani: types and criteria for immunochemical characterization

BACKGROUND

There are no established methods for the preparation and standardization of Fusarium solani antigens. This lack of standardization makes it difficult to use these antigens in allergenic diagnostic tests.

OBJECTIVE

To obtain an appropriate standardized method for the preparation of the different antigen types of F. solani.

METHODS

Production of fungal extracts, followed by biochemical and immunological characterization.

RESULTS

The somatic antigens presented the greatest protein content most of these proteins are common to the metabolic and hydrosoluble antigens, particularly those proteins at 35-39 kDa, 29-32 kDa and 15-16 kDa, as detected by electrophoresis and immunoblotting. The hydrosoluble antigens presented the highest protein diversity; these proteins were the most specific, showing minor determinants in common with the other antigens.

CONCLUSIONS

It is recommended that a mixture of the different antigen sources be used in order to obtain extracts which would cover the maximum number of diagnostic possibilities.

In vitro susceptibility of Cryptococcus neoformans isolates to five antifungal drugs using a colorimetric system and the reference microbroth method

Minimum inhibitory concentrations (MICs) of amphotericin B, 5-flucytosine, fluconazole, itraconazole and ketoconazole were determined against 42 clinical isolates of Cryptococcus neoformans var. neoformans using the Alamar YeastOne colorimetric method and the NCCLS reference microdilution method. No strains with resistance to amphotericin B, itraconazole or ketoconazole were detected with either method. Using the reference method, the MICs of fluconazole were >/= 64 mg/L, whereas using the colorimetric method all MICs were >/=16 mg/L. The MIC values of 5-flucytosine were also higher using the reference method (8-16 mg/L for 32% of isolates) compared with the colorimetric method. The percentage of agreement between the methods, using a difference of two dilutions, was 70.7% for itraconazole, 73.2% for amphotericin B, 80% for fluconazole, 88% for 5-flucytosine and 95% for ketoconazole. Overall, we conclude that for fluconazole and 5-flucytosine, in a low but not insignificant number of isolates, results with the two methods are discordant, some isolates being found sensitive with the colorimetric test, but resistant with the reference method.

[Candidemia in AIDS. A retrospective study of nine cases]

Prevalence of candidemia has increased during the last decade, numerous predisposing factors are invoked, like parenteral drug abuse in the case of brown heroin syndrome, neutropenia, prolonged antibiotic therapeutics and immunosupression. Only a few articles are published about candidemia. Candidemia in AIDS patients seems very low; its incidence is estimated approximately one candidemia per 120 patients.

[Unusual fungal species causing onychomycosis.]

Dermatomycoses caused by non-dermatophytic mycelial fungi are very rare with the exception of onychomycoses. Controversies regarding the pathogenic role often arise when these species and yeasts are isolated from nail scrapings. Candida albicans and Candida parapsilosis are the species identified more frequently from nails, particularly from finger nails. Because they could be resident flora of the skin, cultures should be interpreted according to clinical data, direct microscopic observation of clinical samples, and quantification of colonies. The recognition of other yeasts, such as Candida guillermondii, Candida famata or Candida krusei is more problematic. Isolation of moulds form toe nails accounts for 2 to 12% in different studies, with a prevalence of 7.6% in Barcelona being Scopulariopsis brevicaulis the most frequent species, but Aspergillus versicolor is also a particular etiologic agent of onychomycosis (2.5%). To confirm the etiology of any onychomycosis, standard criteria for mycological diagnosis and identification of moulds should be strictly applied. Experience in the diagnosis of superficial mycosis due to new species of fungi is required for improving current knowledge on the prevalence and clinical importance of this type of infections.

Pathogenicity of Hansenula anomala in model of immunocompromised mice

Systemic infections caused by opportunistic fungi have shown an increased frequency in the past 10 years, particularly in immunocompromised patients. Hansenula anomala is an ascosporogenous yeast of the Ascomycetes class found in the skin, throat, and digestive tract transient normal flora. This study was conducted to compare the pathogenicity of H. anomala and Candida albicans in a model of immunocompromised mice. Thirty-eight Swiss mice were divided into two groups as follows: 30 animals received an intraperitoneal (i.p.) injection of cyclophosphamide (200 mg/kg) four days before the induction of infection with H. anomala (1 x 10(6) yeasts/mL), and 8 animals received 100 mg/kg of cyclophosphamide at 3-day intervals during 3 weeks before inoculation of 1 x 10(7) yeasts/mL. All animals were treated with amoxicillin/clavulanic acid (40 mg/kg) four days before induction of infection. A group of mice inoculated with C. albicans (ATCC 64548) served as control. Tissue samples from the lung, spleen, liver, and kidney for histological and mycologic studies were obtained at necropsy. In each animal, the number of viable yeasts per gram of kidney was determined. The organs most frequently infected by H. anomala were the kidneys and the liver (20%), and the lung (10%). However, in conditions of sustained immunosuppression, H. anomala was found in 65.5% of the organs examined. It is concluded that in an experimental model of immunocompromised mice, the pathogenicity of H. anomala was low.

Multicenter survey of in vitro antifungal resistance in yeasts of medical importance isolated from Spanish patients

Twelve Spanish laboratories collected 325 yeast clinical isolates during a 30 day's period, among them 224 Candida albicans, 30 Candida glabrata, and 27 Candida parapsilosis. In vitro antifungal susceptibility to amphotericin B, ketoconazole, fluconazole and itraconazole was determined by an agar diffusion test (Neo-Sensitabs, Rosco, Denmark). All the isolates tested were susceptible in vitroto amphotericin B and nearly all (97.2%) to itraconazole. In vitrosusceptibility to fluconazole and ketoconazole was high (90.2% and 91.4% of isolates, respectively) but showed variations depending on the species tested. Resistance to fluconazole and ketoconazole was low in C. albicans (4% and 3%, respectively), but 30% of Candida guilliermondii and 36% of C. glabrata isolates were resistant to fluconazole. Ketoconazole resistance was observed in 40% of C. glabrata, and 17% of Candida tropicalis. Resistance to antifungal drugs is very low in Spain and it is related to non-C. albicans isolates.

In vitro susceptibilities of clinical yeast isolates to the new antifungal eberconazole compared with their susceptibilities to clotrimazole and ketoconazole

The antifungal activity of eberconazole, a new imidazole derivative, against 124 clinical isolates of Candida comprising eight different species and to 34 isolates of Cryptococcus neoformans was compared to those of clotrimazole and ketoconazole. MICs of eberconazole, determined by the National Committee for Clinical Laboratory Standards standardized microbroth method, were equal to or lower than those of other azoles, especially for Candida krusei and Candida glabrata, which are usually resistant to triazoles.

Serotyping of Cryptococcus neoformans isolates from clinical and environmental sources in Spain

We determined biovars and serotypes of 154 isolates of Cryptococcus neoformans from clinical and environmental sources from different areas of Spain. All clinical isolates belonged to C. neoformans var. neoformans. Serotypes showed an irregular distribution. C. neoformans var. gattii serotype B was isolated from necropsy specimens from goats with pulmonary disease.

[Topical treatment with eberconazole of the experimental guinea pig cutaneous candidosis.]

Eberconazole is a new azole antifungal drug for topical treatment of superficial mycoses. The usefulness of this drug was evaluated in an experimental model of cutaneous candidosis in guinea pigs comparing with the classical clotrimazole in a single blind trial. Twenty-five animals were inoculated in two symmetrical areas of the back with Candida albicans developing skin infection. One group of 10 animals were treated once per day with clotrimazole 1% cream in one side and with excipient in the other. Other group of 10 guinea pigs received eberconazole 1% cream and excipient. Five animals did not receive any treatment and were used as controls. After five days of treatment most lesions cured or improved and cultures were negative when clotrimazole or eberconazole were applied. Seventy per cent of lesions treated with excipient were clinically improved and 10% cured, but 85% of cultures remained positive for C. albicans. The therapeutic efficacy of eberconazole 1% cream was similar to clotrimazole 1% cream in the guinea ping model of cutaneous candidosis. Tolerance of both drugs was excellent. These results suggest the usefulness of eberconazole in human cutaneous infections due to C. albicans.

Immunochemical characterization of somatic and metabolic antigens of 4 species of Aphanoascus: preliminary results

Aphanoascus spp. are keratinophylic fungi occasionally described as etiological agents of tinea-like dermatomycoses. The goal of this work was to immunochemically characterize somatic and metabolic soluble antigens prepared from 4 species of Aphanoascus. Electrophoresis in SDS-PAGE gel and immunoblotting with sera from rabbits experimentally immunized with both somatic and metabolic antigens have shown a similar pattern among the species analyzed. However, some differences were noted between the species of Aphanoascus. These results suggest the existence of species-specific antigens.

[Oral terbinafine for the tinea unguium of the toenails. Efficacy between 12 and 24 weeks of treament.]

Terbinafine 250 mg po daily was administered to 21 patients affected by tinea unguium of the toenails. In 14 cases Trichophyton rubrum was the aetiological agent while Trichophyton mentagrophytes var. interdigitale affected the rest. The treatment was administered randomized during 12 or 24 weeks in two groups of 11 (group A) and 10 (group B) patients. The clinical and mycological response was evaluated at week 12, 24 and 48. Adverse events were registered during the therapeutic period. At week 24, 55.5% of patients from group A were cured, only one patient did not improve and cultures were positive. In group B 66.6% were cured and three were clinically improved but cultures were positive. In the last control after 48 weeks the results were similar except one patient of the group B who worsened of his nails lesions. Only one case of acute urticaria was noted, the symptoms disappeared after the withdrawal of terbinafine. Terbinafine per os is a safe and effective antifungal for the treatment of the tinea unguium of the toenails. A period of 12 weeks of administration is enough in most of cases but when T. rubrum is the aetiology relapse could be possible.

Aspergillus versicolor as cause of onychomycosis: report of 12 cases and susceptibility testing to antifungal drugs

BACKGROUND

Onychomycoses caused by opportunistic moulds are not well understood, and many are due to Scopulariopsis brevicaulis and other species. Aspergillus versicolor is not documented as an etiological agent in most studies. We have found an increasing prevalence of this species which is involved in 5.8% of all fungal infections of toe nails.

OBJECTIVE

To study the clinical and mycological characteristics of the onychomycosis caused by A. versicolor and the in vitro susceptibility of this mould to antifungal agents.

RESULTS

Onychomycosis due to A. versicolor is mainly seen in people over 60 and presents with chronic involvement of the big toe nails. Predisposing factors are not always present and the infection does not respond to conventional topical antifungals. In vitro, A. versicolor has been shown to be resistant to griseofulvin and fluconazole as well as to amphotericin B, whereas MICs for itraconazole and ketoconazole are variable but within a range of 0.50-4.0 microg/ml; on the contrary, MICs for terbinafine are very low (<0.125 microg/ml).

DISCUSSION

Aspergillus versicolor could be considered as an emergent pathogen causing toenail onychomycosis. Local treatment seems not to be effective. Of the various systemic antifungal agents studied terbinafine appears to be the most effective in treating onychomycosis.

First identification of autochthonous Cryptococcus neoformans var. gattii isloated from goats with predominantly severe pulmonary disease in Spain

Cryptococcus neoformans var. gattii is associated with Eucalyptus trees growing in various tropical and subtropical regions of the world. The identification of 13 autochthonous strains of C. neoformans var. gattii in Spain is reported. These strains were isolated from lung (10 samples), liver (1 sample), and brain (2 samples) tissue specimens from six goats suffering from predominantly severe pulmonary disease that were autopsied. The animals were members of five different herds of goats grazing in rural areas of the province of Cáceres (Extremadura, Spain). Between 1990 and 1994, there were five outbreaks, in which between 2.5 and 12% of the goats were affected. Although respiratory symptoms (pneumonia) associated with cachexia were the predominant clinical picture in all outbreaks, brain and liver involvement was also documented in three of the five outbreaks. Biotyping was performed by culturing the isolates on L-canavanine-glycine-bromothymol blue medium and testing them for the assimilation of D-proline and D-tryptophan. Serotyping by agglutination tests confirmed the characterization of all strains as C. neoformans var. gattii serotype B. This is the first confirmation of the presence of this variety in Spain, with a peculiar ability to produce severe pulmonary and systemic disease in normal goats, particularly in the form of outbreaks of pneumonia in association with cachexia.

Candiduria in non-neutropenic critically-ill surgical patients. Detection of IgA, IgG and IgM antibodies to Candida albicans by germ tube immunofluorescence

The significance of indirect immunofluorescence using Candida albicans germ tube as well as blastospore antigens in the diagnosis of isolated candiduria in non-neutropenic, critically-ill surgical patients was assessed. Ten patients with isolated candiduria, 12 with systemic candidosis and 10 with multifocal muco-cutaneous candidosis were included in the study. The sera of another 10 critically-ill patients with no signs of candidosis served as controls. The patients' sera were tested for IgG, IgA and IgM antibodies. The results obtained confirmed that indirect germ tube immunofluorescence is a useful procedure for differentiating systemic candidosis from colonisation of the urinary tract. Indirect immunofluorescence with blastospores, although more sensitive than germ tube immunofluorescence, cannot distinguish muco-cutaneous candidosis from systemic candidosis. Therefore, indirect germ tube immunofluorescence is regarded a useful complementary test to evaluate candiduria in non-neutropenic, HIV-negative, critically ill patients.

[Minimal inhibitory concentrations of Candida species to five antifungals by using the reference dilution micromethod and the E-test.]

It is accepted that the frequency of candidosis has increased during the last decade, specially in hospitalized patients. The more frequent use of azole antifungals and the recognition of isolates of Candida sp resistant to these and other drugs such as 5-fluorocytosine constitute a great need for a reproducible and useful C. albicans in vitro susceptibility testing method for monitoring antifungal therapy in clinical mycological laboratories. The E-test is a novel agar diffussion technique for testing the susceptibility of yeasts against a defined continous gradient of drug and could be used by most clinical laboratories. In this study the E-test and the NCCLS reference microbroth method (M27-P guidelines) were used to determine the MICs of amphotericin B, 5-flucytosine, itraconazole, fluconazole and ketoconazole for 50 clinical isolates of Candida albicans, Torulopsis glabrata, C. tropicalis and Hansenula anomala and five reference ATCC strains. The main purpose of the study was to compare the results obtained by the two methods. In general good agreement (+/- 1 dilution) was otained between both methods, despite differences observed for some species-antifungal combinations in which the MICs were lower by the E-test than by the microbroth method. MICs for C. albicans and T. glabrata to amphotericin B were < 0.50 microg/mL. Two isolates of C. albicans and two others of H. anomala, showed MIC < 8 microg/mL for 5- flucytosine. All isolates of T. glabrata and 40% of C. albicans showed MICs > 16 microg/mL for fluconazole. The results of this study indicate that E-test is an alternative for susceptibility testing to the NCCLS reference method. Because its simplicity it seems to be an easier test for routine clinical laboratories.

Candidemia in non-neutropenic critically ill patients: analysis of prognostic factors and assessment of systemic antifungal therapy. Study Group of Fungal Infection in the ICU

OBJECTIVE

To determine the incidence and prognosis of candidemia in non-neutropenic critically ill patients, to define mortality-related factors, and to evaluate the results of systemic antifungal therapy.

DESIGN

A prospective multicenter survey in which medical and/or surgical intensive care units (ICUs) in 28 hospitals in Spain participated.

PATIENTS

All critically ill patients with positive blood cultures for Candida species admitted to the participating ICUs over a 15-month period were included.

INTERVENTIONS

Candidemia was defined as the presence of at least one positive blood culture containing Candida species. The follow-up period was defined as the time elapsed from the first positive blood culture for Candida species to discharge or death during hospitalization. Antifungal therapy was considered to be "early" when it was administered within 48 h of the date when the first positive blood culture was obtained and "late" when it was administered more than 48 h after the first positive blood culture.

MEASUREMENTS AND MAIN RESULTS

Candidemia was diagnosed in 46 patients (mean age 59 years), with an incidence of 1 critically ill patient per 500 ICU admissions. The species most frequently isolated were Candida albicans (60%) and C. parapsilosis (17%). Fluconazole alone was given to 27 patients, amphotericin B alone to 10, and sequential therapy to 6. Three patients did not receive antifungal therapy. The overall mortality was 56% and the attributable mortality 21.7%. In the univariate analysis, mortality was significantly associated with a higher Acute Physiology and Chronic Health Evaluation (APACHE) II score at the onset of candidemia (p = 0.04) and with the time elapsed between the episode of candidemia and the start of antifungal therapy 48 h or more later (p < 0.02). Patients with an APACHE II score lower than 21 at the onset of candidemia had a higher probability of survival than patients who were more seriously ill (p = 0.04). Patients with "early" antifungal therapy (< or = 48 h between the onset of candidemia and the start of antifungal therapy) had a higher probability of survival compared with patients with late therapy (p = 0.06). No significant differences were noted between the two groups on different antifungal therapy.

CONCLUSIONS

The incidence of candidemia in ICU patients was very low. An APACHE II score > 20 at the time of candidemia was associated with a higher mortality. Further studies with a large number of patients are needed to assess the effect of early antifungal therapy on the decrease in mortality associated with candidemia and to determine the appropriate dosage of fluconazole and duration of treatment.

Aspergillus fumigatus somatic antigens: comparison between two methods of preparation and immunochemical characterization

Aspergillus fumigatus and other species of the same genus can cause different pathological processes amongst which can be found pulmonary hypersensitivity, intracavitary colonization and invasive and disseminated aspergillosis. The diagnosis of these processes is helped in a great way by the immunological response of the patient to Aspergillus antigens or by the detection of these as a metabolic product in blood and other fluids such as urine. To date, no firm agreement exists regarding the best preparation and standardization technique of aspergillar antigens, which is however the most important step towards the development of immunological diagnostic tests. In this study, two methods for the obtention of A. fumigatus somatic antigens have been compared, using 3 strains of different origins. The main differences between both antigenic extraction methods were the liquid media used for cultures (Czapek and Glucose peptone), the incubation times (4 weeks and 3 days respectively), the type of agitation during the incubation period (intermittent or continuous) and the dialysis and concentration method. The antigens obtained were standardized by the determination of the proteic and hydrocarbonate content, vertical electrophoresis in SDS PAGE, immunoprecipitation and immunoblotting against experimental antisera. From the comparison between both extraction methods, it was found that the highest proteic content was obtained with the somatic antigens of mycelium developed in Czapek for 4 weeks, whereas fungi cultivated in Glucose peptone had a higher glucide content. Vertical electrophoresis revealed the presence of 6 common fractions in all the antigens, whilst some fractions were in majority, only found in one antigen such as the MW 109 kDa, present in the GP 69 antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Ulcerous granulomatous cheilitis with lymphatic invasion caused by Scopulariopsis brevicaulis infection

A 43-year-old man with ulcerous granulomatous cheilitis and submaxillary lymph node invasion caused by Scopulariopsis brevicaulis infection is described. Administration of itraconazole produced a dramatic and definitive cure. Reported cases of deep mycosis caused by S. brevicaulis infection are also reviewed.

[Identification of yeasts of the Candida genus with a growth inhibition system: Microring YT]

BACKGROUND

It has been observed an spectacular increasing of opportunistic Candida yeast infections. Many of them are fatal, and rapid and effective identification of the infecting species contributes to start the correct treatment. Several new methods for yeast identification have become available; Microring YT is one of these methods based on the growth inhibition by 6 different chemical products. The aim of this work is to study the performance of the test using representative clinical yeast isolates.

METHODS

A total of 146 strains belonging to the 5 most common Candida species isolated in the clinical laboratory were identified using conventional methods (germ tube and chlamydospores production, and the standard API 20C AUX and 16 sugars auxonography; Institute Pasteur) and the Microring YT System. This test uses the differing susceptibilities of yeast to 6 discs mounted on a filter paper ring. The chemical products and dyes are: janus green, ethidium bromide, triphenyl tetrazolium chloride, brilliant green, cycloheximide and rhodamine 6G. The inhibition pattern of a 6 digit code is compared with a list of profiles.

RESULTS

Using the Microring YT system 112 of the 146 studied strains were correctly identified with an overall concordance of 77% between this method and the standard one. The morphological study (germ tube production) increased 6% the identification of Candida albicans. Better results were obtained with C. krusei and C. parapsilosis (85% of concordance). With C. glabrata only 59% of concordance was found.

CONCLUSIONS

In spite Microring YT is a simple method, easy to perform and read, it was considered inadequate for the identification of Candida species as a routine microbiological procedure.

Multicenter evaluation of ATB fungus: a standardized micromethod for yeast susceptibility testing

The micromethod for yeast susceptibility testing, ATB Fungus, was evaluated with 30 reference strains in three laboratories. Ready-to-use strips with 5-fluorocytosine, amphotericin B, nystatin, miconazole, econazole and ketoconazole were used. The test allowed the categorization of each strain as susceptible, intermediate or resistance to all the antifungals tested, and 5-fluorocytosine and amphotericin B MIC determination. The results were compared with the MIC for each reference strain obtained by a microdilution method on RPMI 1640 buffered with MOPS. The repeatability and intralaboratory and interlaboratory reproducibility were evaluated. ATB Fungus was a reliable and reproducible method with a repeatability of 96.6%, a reproducibility of 95.4% and showed an excellent correlation 91.7%) with reference MICs.

Identification of the perfect state of Cryptococcus neoformans from 195 clinical isolates including 84 from AIDS patients

Filobasidiella neoformans is the teleomorphic state of Cryptococcus neoformans and it is a heterothalic. The purpose of this study was to establish the proportions of each mating types (a, alpha) from among 195 strains of C. neoformans isolated from clinical material. The culture medium used was sunflower agar. Cultures were incubated at 20-22 degrees C for 15 days and observed periodically for one month. Non-reactive strains were mated several times with different reactive strains. Under these conditions 96.8% of the strains were found to be reactors. Among both varieties of C. neoformans, mating type alpha was found to have the highest frequency of 95% in the variety neoformans and 84% in the variety gattii. These results showed a higher reactivity in comparison with other investigators. This difference could be due to the medium used or to repeated mating with different reactive tested strains.

Renal infection due to Absidia corymbifera in an AIDS patient

A case of renal zygomycosis due to Absidia corymbifera in an heroin addict suffering from AIDS (phase IV C2) is described. Diagnosis was by histopathology after nephrectomy, but A. corymbifera was isolated several times from urine and from the exudate from a fistula in the surgical wound. After amphotericin B treatment (1.5 g overall dose) clinical cure and negative cultures were obtained. No relapses were observed until death 1 year later from Pneumocystis carinii pneumonia.

Extensive dermatophytoses caused by Trichophyton mentagrophytes and Microsporum canis in a patient with AIDS

Retrospective studies have shown the occurrence of episodes of deep or superficial fungal infections in 58 to 81% of HIV/AIDS patients as a result of impairment of cell immunity. We describe a case of disseminated cutaneous dermatophytoses caused by Trichophyton mentagrophytes and Microsporum canis in a patients with AIDS. Diagnostic and therapeutic problems in relation to this unusual presentation are emphasized as well as the importance of an early mycologic diagnosis to prescribe antifungal therapy.