Estudo de moluscos do gênero biomphalaria de Minas Gerais, com relação a adaptação parasito hospedeiro e importância na epidemiologia da esquistossomose

Souza, Cecília Pereira de

doi:10.1590/s0036-46651986000500002

Cited by 14 publications

(4 citation statements)

References 9 publications

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“…The infection rates obtained here ranged from 14.6 to 28.6%, which showed to be higher than those found in literature, quite often lower than 10%, with experimental infections using several snail populations from the State of Minas Gerais (Freitas et al 1972, Gerken et al 1975, Souza et al 1981a, b, 1983, Souza 1986, 1993. Souza et.…”

Section: Discussioncontrasting

confidence: 54%

First report on the presence of Biomphalaria straminea in the municipality of Jaboticatubas, State of Minas Gerais, Brazil

Massara

Carvalho

Caldeira

et al. 2002

Mem. Inst. Oswaldo Cruz

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“…The susceptibility indexes for B. tenagophila are lower than those presented, in the literature, for B. glabrata (approximately 50% to 96%) and, generally higher than those obtained for B. straminea (from 31% to 24%) 11,15,17,28,30,33,42,45,46,48 .…”

Section: Susceptibility Of Biomphalaria Tenagophila Exposed To Schistosomacontrasting

confidence: 72%

Biomphalaria tenagophila (Orbigny, 1835) (Mollusca): adaptation to desiccation and susceptibility to infection with Schistosoma mansoni Sambon, 1907

Ohlweiler

Kawano

2002

Rev. Inst. Med. trop. S. Paulo

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Experiments were carried out to test the susceptibility of Biomphalaria tenagophila to the infection with strain SJ of Schistosoma mansoni in the F1, F2 and non-selected parental generation. The potential adaptation of B. tenagophila to desiccation, in healthy mollusks and those exposed to the larvae of S. mansoni of the F1, F2 and non-selected parental generations was also studied. The presence of mucus and soil, at the shell opening, protected the snails against desiccation, favoring survival. The healthy mollusks performed more attempts against desiccation than those exposed to the larvae of the parasite. The mortality rate, during desiccation, was higher among mollusks that remained buried and with the shell opening unobstructed. During the desiccation period the stage of development of the parasite was influenced by the weight loss and the survival of the snails. The longer the period of desiccation, the greater was the weight loss observed, abbreviating survival. The non-selected parental generation was more sensitive to desiccation than the F1 and F2 generations, both in healthy mollusks and in those exposed to S. mansoni larvae. Healthy mollusks were more resistant to desiccation than those exposed to the larvae of the S. mansoni. Desiccation did not interrupt the development of S. mansoni larvae in mollusks, causing a delay in the cercariae elimination. The susceptibility of B. tenagophila to the SJ strain of S. mansoni, in mollusks maintained in water during the larvae incubation period, was similar in all three generations.

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“…This index can be considered high when compared with the susceptibility data for the species cited in the literature (Gerken et al 1975, Souza et al 1981a, b, 1983, Souza 1986, Fernandez & Thiengo 2002, Massara et al 2002.…”

Section: Discussionmentioning

confidence: 99%

Biomphalaria spp. (Preston, 1910) snails in the municipality of Juiz de Fora, Zona da Mata Mineira mesoregion, ate of Minas Gerais, Brazil

Tibiriçá¹,

Bessa

Mittherofhe³

et al. 2006

Mem. Inst. Oswaldo Cruz

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This study focuses on the geographic distribution of the snail of the genus Biomphalaria and evaluates its infectivity byOf the state's 853 municipalities distributed in the 12 political-administrative mesoregions, 283 have been studied for the snail's prevalence. B. glabrata has been reported in 65.3% of the municipalities studied; B. straminea in 43.8%; B. tenaghophila in 20.4%; B. peregrina in 20.1%; B. schrammi in 9.2%; B. intermedia in 7%, and B. occidentalis in 0.7% . The municipality in Brazil is the local political-administrative division, corresponding roughly to a county or prefecture. It is governed by a mayor and municipal council. Some municipalities are almost completely urbanized, others almost totally rural, and some, like Juiz de Fora, a mixture of the two.The most recent scientific report on the occurrence of Biomphalaria in Juiz de Fora municipality, the main social and economic center in the state's Zona da Mata So, this work focuses on the geographic distribution of Biomphalaria in Juiz de Fora municipality with identification of the species found, possibility of infectivity, and main types of related habitats. This updated study of the occurrence of intermediate hosts in the region confirms, for the first time, the presence of B. straminea in the municipality, with the study of this snail susceptibility of the Juiz de Fora strain to S. mansoni. MATERIALS AND METHODSLocation under study -This study was carried out in the municipality of Juiz de Fora (21S14/42W14), in the mesoregion known as the Zona da Mata Mineira, Minas Gerais, Brazil (Fig. 1). This municipality is located 280 km from Belo Horizonte, the state capital, and 184 km from the city of Rio de Janeiro. Juiz de Fora has a land area of 1,429.875 km 2 , with a population of 419,226 inhabitants according to the 2000 census. The municipality, with an average altitude of 800 m, has an ample hydrographic basin rich in lakes, ponds, and irrigation ditches. The spatial localization of the foci was determined by instant positioning from a GPS (Global Positioning System) apparatus.Malacological survey -These surveys were performed in collaboration with technicians from DADS/Juiz de Fora (Directorate for Decentralized Health Actions, an organ of the State Health Secretariat). The specimens were collected from lotic and lentic ecosystems in the municipality, predominantly around the urban perimeter, where the characteristics are favorable to the occurrence and spatial dispersion of snails near human populations. We captured the specimens with the aid of tongs and nets. The study was conducted in 2003 to 2004.Snails -After collection, the snails were taken to the laboratory where the living specimens were measured. After examination under artificial light for S. mansoni cercarie, the snails were submitted to squeezing between glass plates to detect the presence of cercariae. Some specimens were separated for morphological identification (Paraense 1975). Another sample of specimens was packed and sent to the René-Rachou Research Center for mole...

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“…Thus, the conventional techniques are not suitable for detecting S. mansoni in these less susceptible species, due to the long time spent and the mortality of the snails 10 . Biomphalaria straminea and B. tenagophila infection rates, in experimental infections, according to several authors, are normally lower 1,2,3,13,14,16 , probably due to the snails mortality before eliminating cercariae. Facing the limitations of the traditional diagnosis methods, other faster and more efficient techniques have been developed based on the detection of the parasite DNA profile in B. glabrata 5,6,7 .…”

Section: Introductionmentioning

confidence: 92%

Susceptibility of Biomphalaria tenagophila and Biomphalaria straminea to Schistosoma mansoni infection detected by low stringency polymerase chain reaction

Jannotti-Passos

Souza

2000

Rev. Inst. Med. trop. S. Paulo

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SUMMARYIn order to determine Schistosoma mansoni infection rates in Biomphalaria tenagophila and B. straminea, low stringency polymerase chain reaction (LS-PCR) technique was used as a complementary method to light exposure technique. LS-PCR has already been standardized in our laboratory to detect the trematode DNA in B. glabrata. Higher S. mansoni infection rates were detected using conventional method and LS-PCR. The parasite DNA profile was detected in both species after 7-day exposure to miracidia, using LS-PCR. This technique enables early detection of schistosomiasis transmission focuses, in endemic areas, before the beginning of cercariae shedding.

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Estudo de moluscos do gênero biomphalaria de Minas Gerais, com relação a adaptação parasito hospedeiro e importância na epidemiologia da esquistossomose

Cited by 14 publications

References 9 publications

First report on the presence of Biomphalaria straminea in the municipality of Jaboticatubas, State of Minas Gerais, Brazil

Biomphalaria tenagophila (Orbigny, 1835) (Mollusca): adaptation to desiccation and susceptibility to infection with Schistosoma mansoni Sambon, 1907

Biomphalaria spp. (Preston, 1910) snails in the municipality of Juiz de Fora, Zona da Mata Mineira mesoregion, ate of Minas Gerais, Brazil

Susceptibility of Biomphalaria tenagophila and Biomphalaria straminea to Schistosoma mansoni infection detected by low stringency polymerase chain reaction

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