FROGLOG - Amphibian Specialist Group

Batrachochytrium dendrobatidis infects M. moreirae from an Atlantic rainforest, brazilContinued from previous pageIn Brazil, reported declines ofamphibian populations comemainly from the Atlantic Rainforest,and also from the Cerrado(Heyer et al., 1981; Weygoldt,1989, Guix et al., 1998, Eterovicket al., 2005). B. dendrobatidis hasalready been reported from severalspecies in the Atlantic Rainforest,from Rio Grande do Sul (southernmoststate) to Pernambuco (northeastern)(Toledo et al., 2006, Carnavalet al., 2006). However, thereis not enough data to link B. dendrobatidisto amphibian declines inBrazil.Melanophryniscus moreirae is asmall bufonid (mean adult bodysize < 20mm) found in the ItatiaiaPlateau and in the SerraFina, southeast Brazil, alwaysabove 2,000 m (Bokerman, 1967;Marques et al, 2006). These toadsare diurnal, and breed in shallowpuddles from September to December(Bokerman, 1967; Starret,1967; Guido-Castro, 2006).M. moreirae has been reported as‘declining’ by Guix et al. (1998),but no systematic monitoring ofthis endemic toad has been carriedout.Herein we report the occurrenceof B. dendrobatidis infecting thetoad M. moreirae using Real timePCR.The study was carried out on theItatiaia Plateau in the Itatiaia NationalPark (PNI), located 44º34’to 44º42’ W, and 22º16’ to 22º28’S, southeast of Brazil. Field workwas carried out in spring 2006(October and November) as part ofa monitoring program. Fifty adultmales were captured between 09hand 16h in individual new plasticbags, in which they were measuredfor snout-urostyle length(SUL) with a calipers (precision =0.1mm). We firmly ran one swab(Medical Wire & Equipment Co.)in different parts of the frog’s body(Kriger et al., 2006). All animalswere released after sampling.We analyzed swabs using quantitative(real-time) PCR techniques(Boyle et al. 2004, Krigeret al., 2006). We classified eachsample as positive or negative forinfection with Batrachochytriumdendrobatidis. Our estimates ofthe number of zoospores representthe mean value of B. dendrobatidisgenome equivalentsdetected in the three runs of thePCR analysis.Two individuals (SUL =24.9mm and 26.1mm) were infectedwith B. dendrobatidis, correspondingto a prevalence (sensuBush et al., 1997) of 4%. Thenumbers of zoospore equivalentswere low in both individuals (1.4and 1.5 zoospore equivalents, respectively).No evident clinical orabnormal signs were observed inthese frogs.This is the first report of B. dendrobatidisin M. moreirae and thefirst for the genus. Even thoughthe prevalence and severity of infectionwere low, this result suggestsprecautionary measures betaken considering the restrictedgeographic range of M. moreirae.Monitoring of M. moreirae aswell as the possible evolution ofthe pathogen in this populationshould contribute to our currentunderstanding of the dynamics ofthis disease and to accurately determinethe impact of B. dendrobatidison this endemic species.Acknowledgements.We thank CNPq and Biodiversitasfor fundings. D. Boyle fromCSIRO, Australia, provided thestandards. We appreciate the financialsupport provided by RANA forone of the authors (TKF) to attendthe workshop on chytrid investigation.ReferencesBerger L, Speare R, Hyatt AD(1999) Chytrid fungi and amphibiandeclines: overview, implicationsand future directions. In: CampbellA (ed) Declines and disappearancesof Australian frogs. EnvironmentAustralia: Canberra, p 23-33.Boyle, DG, Boyle DB, OlsenV, Morgan JAT, Hyatt AD (2004)Rapid quantitative detection ofchytridiomycosis (Batrachochytriumdendrobatidis) in amphibiansamples using real-time TaqmanPCR assay. Dis. Aquat. Org.60:141-148.Bokermann, WCA (1967) Observaçõessobre Melanophryniscusmoreirae (Mir. Rib.) (Amphibia -Brachycephalidae). An. Acad. Bras.Cienc. 39(2):301-306.Bush AO, Lafferty KD, Lotz JM,Shostak AW (1997) Parasitologymeets ecology on its ows terms:Margolis et al revisited. J Parasitol83(4): 575-583.Carnaval, ACOQ, PuschendorfR, Peixoto, OL, Verdade, VK, Rodrigues,MT (2006) Amphibianchytrid Fungus Broadly distributedin the Brazilian Atlantic Rain Forest.EcoHealth, 2006:1-8.Daszak P, Scott DE, FaggioniC, Kilpatrick AM, Gibbons JW,Porter D (2005) Amphibian pop-7