Cryptococcal Meningitis in a Mexican Neurological Center.

BACKGROUND: Cryptococcal meningitis, one of the most severe infections affecting the central nervous system, often involves severe neurological sequels and high mortality. METHODS: A retrospective review was performed, including 76 cases admitted in a 10-year period at a neurological referral center in Mexico City. From 68 isolates, 52 fungal specimens were identified as part of the Cryptococcus neoformans var. neoformans complex, 15 as C. neoformans var gattii complex, and one as Cryptococcus non- neoformans/gattii . RESULTS: Higher cryptococcal meningitis incidence and severity were found in HIV-infected men; other risk factors frequently observed were diabetes mellitus and labor exposure to poultry. The main clinical manifestations were subacute headache, cognitive alterations, and photophobia (exclusively in HIV patients). MRI was highly sensitive for pathologic findings such as meningeal enhancements and cryptococcomas, most of them associated to C. neoformans complex. Eleven patients developed severe brain vasculitis, as observed by transcranial Doppler. Hydrocephalus with intracranial hypertension was the most frequent complication. CONCLUSIONS: One-half of the population died, and the rest had neurological sequels, mainly neuropsychiatric manifestations and secondary headaches. These patients developed severe functional limitations in performing daily activities in an independent manner.

MLST and Whole-Genome-Based Population Analysis of Cryptococcus gattii VGIII Links Clinical, Veterinary and Environmental Strains, and Reveals Divergent Serotype Specific Sub-populations and Distant Ancestors.

The emerging pathogen Cryptococcus gattii causes life-threatening disease in immunocompetent and immunocompromised hosts. Of the four major molecular types (VGI-VGIV), the molecular type VGIII has recently emerged as cause of disease in otherwise healthy individuals, prompting a need to investigate its population genetic structure to understand if there are potential genotype-dependent characteristics in its epidemiology, environmental niche(s), host range and clinical features of disease. Multilocus sequence typing (MLST) of 122 clinical, environmental and veterinary C. gattii VGIII isolates from Australia, Colombia, Guatemala, Mexico, New Zealand, Paraguay, USA and Venezuela, and whole genome sequencing (WGS) of 60 isolates representing all established MLST types identified four divergent sub-populations. The majority of the isolates belong to two main clades, corresponding either to serotype B or C, indicating an ongoing species evolution. Both major clades included clinical, environmental and veterinary isolates. The C. gattii VGIII population was genetically highly diverse, with minor differences between countries, isolation source, serotype and mating type. Little to no recombination was found between the two major groups, serotype B and C, at the whole and mitochondrial genome level. C. gattii VGIII is widespread in the Americas, with sporadic cases occurring elsewhere, WGS revealed Mexico and USA as a likely origin of the serotype B VGIII population and Colombia as a possible origin of the serotype C VGIII population. Serotype B isolates are more virulent than serotype C isolates in a murine model of infection, causing predominantly pulmonary cryptococcosis. No specific link between genotype and virulence was observed. Antifungal susceptibility testing against six antifungal drugs revealed that serotype B isolates are more susceptible to azoles than serotype C isolates, highlighting the importance of strain typing to guide effective treatment to improve the disease outcome.

Molecular identification of coccidioides isolates from Mexican patients.

Molecular studies of the genome of the fungus Coccidioides have demonstrated two nearly identical, but well-identified species, Coccidioides immitis and C. posadasii, known as "California" and "non-California" species, respectively. The objective of this study was to determine, through molecular methods, whether both species of Coccidioides are present in Mexican patients with coccidioidomycosis and to estimate, their geographical distribution in Mexico. We analyzed 56 clinical isolates of Coccidioides spp. from Mexican patients. Molecular identification of each strain was done by means of real time PCR using TaqMan(R) probes to amplify single nucleotide polymorphisms (SNPs) in four target sequences, loci, named proline 157, proline 174, hexokinase 149 and glucose-synthase 192. SNP analysis identified two of the 56 isolates as Coccidioides immitis and the remaining 54 as C. posadasii. The dual probe assay that included proline 157, proline 174 and glucose-synthase 192 gave consistent results on SNP differentiation between the two species. In contrast, the template matching hexokinase 149 gave negative results for any species in 34 samples. Our results did not show geographical overlap of the species, and they also confirmed that C. posadasii is the most frequent species in Mexico. A vast majority of C. posadasii strains were localized in the north-central region of the country.

Observaciones de micosis pulmonares oportunistas / Opportunistic pulmonary mycosis

Para conocer la frecuencia y tipo de micosis oportunistas en 240 pacientes internados en un hospital de neumología, se practicaron historia clínica y estudios micológicos consistentes en el aislamiento de hongos a partir de muestras de esputo. En cada paciente se tomaron tres muestras seriadas, las cuales fueron procesadas por examen directo, frotis y cultivo de Sabouraud. Con la metodología empleada, los resultados mostraron que de los 240 pacientes en 191 se aislaron una o más especies de hongos oportunistas (79,5%). Sin embargo, de acuerdo a la valoración clínica y a los parámetros de laboratorio, se pudo hacer el diagnóstico de candidosis pulmonar en 57 pacientes (23,7% del total), siendo la micosis oportunista la de mayor frecuencia. Otras micosis observadas fueron: aspergilosis (once), geotricosis (ocho), y nocardiosis (cinco). Asimismo se comenta la utilidad y el valor diagnóstico que tienen los estudios micológicos en el análisis clínico de pacientes con micosis oportunista

Algunos aspectos epidemiologicos de las dermatofitosis: I. Frecuencia de infección / Some epidemiological aspects of dermatophytosis: I. Frequency of infection

Se estudiaron 488 casos de dermatofitosis en adultos, de los cuales 312 (63.93%) correspondieron al sexo masculino y 176 (36.07%) al femenino. Las regiones corporales más afectadas fueron uñas de pies (42.21%), pies (30.12%) e ingles (13.12%). En la mayoría de los casos el diagnóstico se hizo tanto por el examen directo como por el cultivo (66.19%); por el examen directo en el 26.23% y por el cultivo en el 7.58%. Las especies más frecuentes fueron Trichophyton rubrum (78.85%), T. mentagrophytes (8.52%), Microsporum, canis (4.95%) y Epidermophyton floccosum (4.12%). Se discute el fenómeno del aumento progresivo en la frecuencia de T. rubrum y a la disminución de T. tonsurans