RESUMO
Over the past two decades, several fungal outbreaks have occurred, including the high-profile 'Vancouver Island' and 'Pacific Northwest' outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause of several additional case clusters at localities outside of the tropical and subtropical climate zones where the species normally occurs. In every case, the causative agent belongs to a previously rare genotype of C. gattii called AFLP6/VGII, but the origin of the outbreak clades remains enigmatic. Here we used phylogenetic and recombination analyses, based on AFLP and multiple MLST datasets, and coalescence gene genealogy to demonstrate that these outbreaks have arisen from a highly-recombining C. gattii population in the native rainforest of Northern Brazil. Thus the modern virulent C. gattii AFLP6/VGII outbreak lineages derived from mating events in South America and then dispersed to temperate regions where they cause serious infections in humans and animals.
Assuntos
Criptococose/microbiologia , Cryptococcus gattii/genética , Animais , Brasil , Colúmbia Britânica/epidemiologia , Células Cultivadas , Criptococose/epidemiologia , Cryptococcus gattii/classificação , Cryptococcus gattii/patogenicidade , Surtos de Doenças , Genes Fúngicos , Humanos , Funções Verossimilhança , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Noroeste dos Estados Unidos/epidemiologia , Filogenia , Polimorfismo de Fragmento de Restrição , Árvores , Clima Tropical , VirulênciaRESUMO
BACKGROUND: Methicillin-resistant Staphylococcus aureus is an increasing problem in the Caribbean. We investigated the molecular epidemiology of MRSA isolates on Cuba. FINDINGS: The predominant clone was of the spa type t149, followed by community-associated MRSA USA300. CONCLUSIONS: We report the first molecular typing results of MRSA isolates from Cuba.
RESUMO
Lethargic Crab Disease (LCD) caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Brachyura: Ocypodidae) along the Brazilian coast, mainly in the Northeastern region. The disease was named after the symptoms of slow movement of infected crabs. Causative agents were suspected to be two black yeast-like fungi of the family Herpotrichiellaceae (ascomycete order Chaetothyriales), judged by infected tissue biopsies from moribund U. cordatus. The aim of the present study is to prove that two species are involved in the disease: the recently described black yeast Exophiala cancerae, but also a less virulent, hitherto undescribed fonsecaea-like species, introduced here as the novel species Fonsecaea brasiliensis. Strains were identified by ITS rDNA sequencing, and species borderlines were established by multilocus sequencing and AFLP analysis. Fonsecaea brasiliensis proved to be closely related to the pathogenic species Cladophialophora devriesii which originally was isolated from a systemic infection in a human patient. The virulence of F. brasiliensis is lower than that of E. cancerae, as established by artificial inoculation of mangrove crabs.
Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Braquiúros/microbiologia , Exophiala/classificação , Exophiala/isolamento & purificação , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Ascomicetos/genética , Ascomicetos/patogenicidade , Braquiúros/genética , Brasil , Exophiala/genética , Exophiala/patogenicidade , Tipagem de Sequências Multilocus , FilogeniaRESUMO
BACKGROUND: Cryptococcus neoformans is commonly associated with meningoencephalitis in immunocompromised patients and occasionally in apparently healthy individuals. Recurrence of infection after initial treatment is not uncommon. We studied C. neoformans isolates from 7 Cuban patients with recurrent cryptococcal meningitis. Antifungal susceptibility and genotyping with microsatellite molecular typing were carried out. METHODS: Isolates (n = 19) were recovered from cerebrospinal fluid, blood, urine and semen. Antifungal susceptibilities for amphotericin B, fluconazole, flucytosine, itraconazole, voriconazole, posaconazole and isavuconazole were tested by CLSI M27A3 broth microdilution method. Genotyping was done using a panel of 9 microsatellite (STR) markers: (CT)n, (TG)n, (TA)n, (CTA)n, (TCT)n, (CCA)n, (TTAT)n, (ATCC)n and (TATT)n. RESULTS: The average number of isolates/patient was 2.71. The mean time interval between the collection of any two isolates was 52.5 days. All strains were identified as C. neoformans var. grubii (serotype Aα). Although none of the strains were resistant to the studied drugs, in serial isolates from two patients, MICs values of triazoles increased 4-5 log2 dilutions over time. STR patterns showed 14 distinctive profiles. In three patients the recurrent infection was associated with genotypically identical isolates. The four other patients had relapse isolates which were genotypically different from the initial infecting strain. CONCLUSION: Recurrences of cryptococcal meningitis in our series of patients was not associated with development of drug resistance of the original strain but by an initial infection with different strains or a reinfection with a new strain.
Assuntos
Antifúngicos/farmacologia , Cryptococcus neoformans/classificação , Cryptococcus neoformans/efeitos dos fármacos , Meningite Criptocócica/microbiologia , Repetições de Microssatélites , Técnicas de Tipagem Micológica , Sangue/microbiologia , Líquido Cefalorraquidiano/microbiologia , Cryptococcus neoformans/genética , Cryptococcus neoformans/isolamento & purificação , Cuba , DNA Fúngico/genética , Feminino , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Recidiva , Sêmen/microbiologia , Urina/microbiologiaRESUMO
BACKGROUND: Human cryptococcal infections have been associated with bird droppings as a likely source of infection. Studies toward the local and global epidemiology of Cryptococcus spp. have been hampered by the lack of rapid, discriminatory, and exchangeable molecular typing methods. METHODOLOGY/PRINCIPAL FINDINGS: We selected nine microsatellite markers for high-resolution fingerprinting from the genome of C. neoformans var. grubii. This panel of markers was applied to a collection of clinical (n = 122) and environmental (n = 68; from pigeon guano) C. neoformans var. grubii isolates from Cuba. All markers proved to be polymorphic. The average number of alleles per marker was 9 (range 5-51). A total of 104 genotypes could be distinguished. The discriminatory power of this panel of markers was 0.993. Multiple clusters of related genotypes could be discriminated that differed in only one or two microsatellite markers. These clusters were assigned as microsatellite complexes. The majority of environmental isolates (>70%) fell into 1 microsatellite complex containing only few clinical isolates (49 environmental versus 2 clinical). Clinical isolates were segregated over multiple microsatellite complexes. CONCLUSIONS/SIGNIFICANCE: A large genotypic variation exists in C. neoformans var. grubii. The genotypic segregation between clinical and environmental isolates from pigeon guano suggests additional source(s) of human cryptococcal infections. The selected panel of microsatellite markers is an excellent tool to study the epidemiology of C. neoformans var. grubii.