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
Hypertonic (3.0%) saline (HS) resuscitation from hemorrhagic shock is associated with less cerebral edema and lower intracranial pressure (ICP) compared to normal saline (NS) and 10% Dextran 40 (D-40). The effect of HS resuscitation on cerebral blood flow (CBF) is unknown. Beagle dogs with a head injury underwent shock and resuscitation, receiving either NS (N = 6), HS (N = 6), or D-40 (N = 6). CBF (via a microsphere technique) and ICP were measured at baseline (BL) and at end shock (ES) after infusion of shed blood and test fluid (ER) and 2 hours after resuscitation (LR). CBF was determined globally (GCBF), and for the right (RCBF) and left (LCBF) cerebral hemispheres. ICP values (+/- SEM) at BL and ES were 10.8 +/- 1.31 mmHg and 8.0 +/- 1.67 mmHg, respectively, for all groups. GCBF, RCBF and LCBF at BL were 29.4 +/- 5.04, 26.7 +/- 4.93 and 26.6 +/- 4.50 ml 100 g-1 min-1, respectively. ES values for CBF were not significantly different from BL. Global and hemispheric CBF values were not different between groups at times measured. ICP was significantly lower in animals receiving HS. Therefore, lower ICP following HS resuscitation is not associated with alteration in CBF.
Assuntos
Encéfalo/irrigação sanguínea , Traumatismos Craniocerebrais/terapia , Hidratação , Pressão Intracraniana , Choque Hemorrágico/terapia , Animais , Cães , Soluções Isotônicas , Solução Salina HipertônicaRESUMO
Hypertonic (3.0%) saline (HS) resuscitation from hemorrhagic shock is associated with less cerebral edema and lower intracranial pressure (ICP) compared to normal saline (NS) and 10% Dextran 40 (D-40). The effect of HS resuscitation on cerebral blood flow (CBF) is unknown. Beagle dogs with a head injury underwent shock and resuscitation, receiving either NS(N = 6), HS (N = 6) or D-40 (N = 6). CBF (via a microsphere technique) and ICP were measured at baseline (BL) and at end shcok (ES) after infusion of shed blood and test fluid (ER) and 2 hours afyter reuscitation (LR). CBF was determined globally (GCBF), and for the right (RCBF) and left (LCBF) cerebral hemispheres. ICP values (ñ SEM) at BL and ES were 10.8 ñ 1.31 mmHg and 8.0 ñ 1.67 mmHg, repectivel, for all groups. GCBF, RCBF and LCBF at BL were 29.4 ñ 5.04, 26,7 ñ 4.93 and 26.6 ñ 4.50 ml 100 g-1 min -1, respectively. ES values for CBF were not significantly different from BL. global and hemisphyeric CBF values were not different between groups at times measured. ICP was significantly lower in animals receiving HS. Therefore, lower ICP dollowing HS resuscitation is not associated with alteration in CBF