Cryptococcus neoformans-Cryptococcus gattii species complex: an international study of wild-type susceptibility endpoint distributions and epidemiological cutoff values for fluconazole, itraconazole, posaconazole, and voriconazole.

Epidemiological cutoff values (ECVs) for the Cryptococcus neoformans-Cryptococcus gattii species complex versus fluconazole, itraconazole, posaconazole, and voriconazole are not available. We established ECVs for these species and agents based on wild-type (WT) MIC distributions. A total of 2,985 to 5,733 CLSI MICs for C. neoformans (including isolates of molecular type VNI [MICs for 759 to 1,137 isolates] and VNII, VNIII, and VNIV [MICs for 24 to 57 isolates]) and 705 to 975 MICs for C. gattii (including 42 to 260 for VGI, VGII, VGIII, and VGIV isolates) were gathered in 15 to 24 laboratories (Europe, United States, Argentina, Australia, Brazil, Canada, Cuba, India, Mexico, and South Africa) and were aggregated for analysis. Additionally, 220 to 359 MICs measured using CLSI yeast nitrogen base (YNB) medium instead of CLSI RPMI medium for C. neoformans were evaluated. CLSI RPMI medium ECVs for distributions originating from at least three laboratories, which included ≥95% of the modeled WT population, were as follows: fluconazole, 8 µg/ml (VNI, C. gattii nontyped, VGI, VGIIa, and VGIII), 16 µg/ml (C. neoformans nontyped, VNIII, and VGIV), and 32 µg/ml (VGII); itraconazole, 0.25 µg/ml (VNI), 0.5 µg/ml (C. neoformans and C. gattii nontyped and VGI to VGIII), and 1 µg/ml (VGIV); posaconazole, 0.25 µg/ml (C. neoformans nontyped and VNI) and 0.5 µg/ml (C. gattii nontyped and VGI); and voriconazole, 0.12 µg/ml (VNIV), 0.25 µg/ml (C. neoformans and C. gattii nontyped, VNI, VNIII, VGII, and VGIIa,), and 0.5 µg/ml (VGI). The number of laboratories contributing data for other molecular types was too low to ascertain that the differences were due to factors other than assay variation. In the absence of clinical breakpoints, our ECVs may aid in the detection of isolates with acquired resistance mechanisms and should be listed in the revised CLSI M27-A3 and CLSI M27-S3 documents.

Effectiveness of terbinafine in the eradication of Microsporum canis from laboratory cats.

In this study, the coats of 20 cats with no dermatophytosis lesions were sampled for colonization by Microsporum canis, which was isolated in 45% of cases. All cats were treated with oral terbinafine for 3 weeks. The drug was administered orally at a daily dosage 8.25 mg kg-1. Mycologic status was assessed at the end of the treatment; and after follow-up at 2 days, and 4 and 9 weeks. The final evaluation revealed a complete mycologic cure of all cats by obtaining negative cultures, thereby demonstrating that terbinafine is an effective method of eradication of dermatophyte colonization.

Frequency of Cryptococcus species and varieties in México and their comparison with some Latin American countries.

Cryptococcosis frequency is increasing in Mexico. Few epidemiologic and clinical surveys exist even though 10-15% of patients with AIDS develop this mycosis. To know the situation about the prevalence and etiological agents of cryptococcosis in our country, a study including isolated Cryptococcus spp. strains took place from 1989 to August 1998. A total of 211 Cryptococcus spp. strains obtained from patients of diverse hospital centers in Mexico City were studied. This study describes cryptococcosis epidemiological data, in our country. C. neoformans was the dominant isolation (97.15%), followed by two C. albidus isolation and one C. uniguttulatus isolation. 92.5% of the strains was isolated from cerebral spinal fluid and the remaining were from bone marrow, blood, ganglion, sputum, bronchial lavage and liver biopsy. AIDS was the principal opportunistic factor (85%). Strains were found prevails in males (87.3%). It was found that the age groups where the disease appears most frequently are in the fourth (37.5%) and third (33.8%) decade of life. Finally, the isolation frequency of the C. neoformans var. neoformans (vn) and var. gattii (vg) obtained in this study (vn 86.7%) and vg 10.4%) was compared with the ones registered in Argentina (vn 97.6%, vg 2.4%); Brazil (vn 83.3%, vg 15.8%); Cuba (vn 97.6%, vg 2.4%); Paraguay (vn 0%, vg 100.0%); Puerto Rico (vn 100.0%, vg 0%) and Venezuela (vn 66.7%, vg 29.6%).

Crytococcus neoformans var. gattii in an AIDS patient: first observation in Mexico.

We report the first, as far as we know, Mexican case of meningitis caused by Cryptococcus neoformans var. gattii serotype B associated with AIDS in a female patient. The HIV was transmitted to the patient through a blood transfusion. This patient represents, worldwide, the ninth case of C. neoformans var. gattii in patients with AIDS.

Cryptococcus neoformans var. gattii among patients with cryptococcal meningitis in Mexico. First observations.

A retrospective study of 20 patients with cryptococcal meningitis and their isolated strains was performed. Cryptococcus neoformans var. neoformans was recovered from 14 (70%) cases, and var. gattii was recovered from six (30%) patients. Twelve patients had AIDS (all carrying var. neoformans), two had other diseases (one with var. neoformans and one var. gattii) and there was no identifiable underlying disease in six (one var. neoformans and five var. gattii). Fourteen patients (11 var. neoformans and three var. gattii) resided in the Mexico City area, where a temperate climate is prevalent, and there were six cases (three var. neoformans and three var. gattii) from states with a tropical/subtropical climate. Although there was no significant statistical difference between the two varieties, the fatal outcome was higher in patients with var. neoformans. The disease caused by var. gattii strains was characterized by a higher opening pressure, more inflamatory changes of CSF and a longer clinical course (delayed clinical and mycological cure). Cryptococcus neoformans var. gattii is a significant cause of cryptococcal meningitis in patients without underlying diseases in Mexico.

Isolation of Cryptococcus neoformans var. neoformans from bird droppings, fruits and vegetables in Mexico City.

The presence of Cryptococcus neoformans in various natural sources, such as bird droppings, fruits and vegetables, was investigated. A total of 711 samples were analyzed; C. neoformans var. neoformans was isolated from seven out of 74 bird droppings (9.5%), with parrots as one of the most significant sources. Fruits were positive in 9.5% of the 169 samples studied, specially citrus fruits, particularly grapefruit, in which the highest frequency was found. From the 468 vegetable samples, only 20 were positive (4.2%). It is emphasized that five of the positive vegetables species are autochthonous to Mexico: avocado (Nectandra salicifolia), beet (Beta vulgaris var. quinopodiace), chayote (Sechium edule), stringbean (Cassia sp), and nopal (Opuntia ficus-indica).

Isolation of Cryptococcus neoformans from pigeon (Columba livia) droppings in Mexico City.

To determine the ecological and epidemiological significance of pigeon excrement in cryptococcosis in Mexico City, 251 samples of pigeon droppings were studied. These were collected from houses, public buildings, churches, parks and pigeon nests. Each sample was suspended 1:10 in isotonic saline solution and then cultured in Staib medium. Identification of Cryptococcus neoformans was performed based on the development of brown-coloured colonies and the presence of encapsulated yeasts. Of 251 samples, 52 (20.7%) were positive for Cr. neoformans. The highest frequency was observed in droppings from public buildings (31.2%), followed by churches (22.0%) and houses (13.3%). No significant differences in isolation frequency were observed between fresh or dried excrement. All isolates obtained were Cr. neoformans var. neoformans. As in other studies on Cr. neoformans from pigeons, performed in other countries, these frequency data are considered 'normal'. The results, however, accentuate the potential risk of cryptococcosis acquisition, especially now that cryptococcosis frequency is increasing in Mexico, mainly in AIDS patients.