Influence of variables on centrifuge-flotation technique for recovery of Toxocara canis eggs from soil

The purpose of this study was to evaluate the influence of variables in a flotation technique for the recovery of Toxocara canis eggs from soil. The trials were done under standardized conditions on one gram of previously sterilized soil samples contaminated with 200 eggs of T. canis. The following variables were evaluated in serial steps: sieving; type of wash; time of stirring; resuspension of sediment; solution flotation. Centrifuge-flotation in sodium nitrate (d = 1.20 g/cm³) was adopted as an initial technique, using Tween 80 (0.2%) and decinormal sodium hydroxide as solutions for washing the samples. Ten tests were done to compare the variables, using counting in triplicate. The sieving of the material reduced significantly the recovery of eggs (p < 0.001) and the number of eggs recovered was higher when the sediment was resuspended (p < 0.05). After standardization, flotation solutions sodium chloride, zinc sulfate, sodium dichromate, magnesium sulfate, and sodium nitrate (d = 1.20g/cm³) were compared. The best results were obtained by using zinc sulfate solution. In conclusion, the chances of recovering T. canis eggs from samples using flotation solutions can be increased by washing of soil twice using distilled water, and resuspension of sediment. On the other hand, the sieving procedure can drastically reduce the number of eggs.

ASSESSMENT OF THE PRESENCE OF Toxocara EGGS IN SOILS OF AN ARID AREA IN CENTRAL-WESTERN ARGENTINA

With the aim of studying the contamination of soils with eggs of Toxocara spp. in an arid area in the central-western region of Argentina, 76 soil samples were collected from 18 towns belonging to six provinces of central-western Argentina. They were processed by the centrifugal flotation method. No eggs of Toxocara spp. were found. It can be concluded that the negative results are directly related to the characteristics of the environment and climate present in the studied area. The finding of eggs in soils depends on several factors: the presence of canine or feline feces, the hygienic behavior of pet owners, the presence of stray animals without veterinary supervision, the weather and environmental conditions, and laboratory techniques used; and all these circumstances must be considered when comparing the results found in different geographical regions. In order to accurately define the importance of public spaces in the transmission of infection to humans, it is important to consider the role of backyards or green spaces around housing in small towns, where the population is not used to walking pets in public spaces, and in such cases a significant fraction of the population may acquire the infection within households.

OCCURRENCE OF Calodium hepaticum (BANCROFT, 1893) MORAVEC, 1982 EGGS IN FECES OF DOGS AND CATS IN LAGES, SANTA CATARINA, BRAZIL

This study aims to report the incidence of Calodium hepaticum among dogs and cats, pets or stray animals, captured by the Zoonosis Control Center (CCZ) in Lages, Santa Catarina, Brazil. Fecal samples from 108 pet dogs and eight pet cats, and from 357 stray dogs and 97 stray cats, captured by CCZ, were analyzed within the period from July 2010 to November 2012. Coproparasitological exams were performed by techniques of sedimentation, centrifuge-flotation, and simple flotation. Among 465 fecal samples from dogs and 105 from cats, the overall spurious infections for C. hepaticum eggs were 1.05%. For dogs, this positivity was 0.43% and for cats it was 3.81%. The two positive dogs were stray and out of the four cats, three were stray and one was a pet. Although the occurrence of C. hepaticum eggs was low, these data reveal the existence of infected rodents, especially in public places, since, out of the six infected animals, five (83.33%) were stray. These results are discussed and analyzed with an emphasis on the risk to public health.

Environmental contamination by Toxocara sp eggs in public areas of Salvador, Bahia state, Brazil

A survey ofparasite eggs and cysts in soil and dog feces collected in public places of 23 boroughs of Salvador, a city in the Northeast of Brazil, was performed. High degree of contamination by Toxocara sp eggs was observed in all boroughs studied; other parasites found included: Ascaris lumbricoides, hookworms, whipworms and protozoan cysts. Parks andpublic gardens were more contaminated than streets and beachesfor all parasites, including Toxocara sp.

In vitro study on thiabendazole action on viability of Ascaris lumbricoides (Lineu, 1758) eggs

The in vitro activity of thiabendazole on Ascaris lumbricoides eggs, which were recovered from uteri of worm excreted after chemotherapeutic treatment, was studied. Four concentrations of the drug were used: 1 -- 2.5 -- 5 -- and 10 ppm during 24, 48 and 72 hours of exposure. Subsequently, the eggs were centrifuged, washed three times and H2SO4 0.1N was added. The eggs were maintained in an incubator for 20 days at 28°C. Finally, the percentage of embryonated eggs was determined under a lightmicroscope at a 100X magnification. After 48 and 72 hours of thiabendazole exposure, at a concentration of 10ppm, the drug showed complete inhibition of egg embryonation.

Antigens of worms and eggs showed a differentiated detection of specific IgG according to the time of Schistosoma mansoni infection in mice

INTRODUCTION: The correlation between the immunological assay and the antibody titer can offer a tool for the experimental analysis of different phases of the disease. METHODS: Two simple immunological assays for Schistosoma mansoni in mice sera samples based on specific IgG detection for worms soluble antigens and eggs soluble antigens were standardized and evaluated in our laboratory. Fifty mice were used in negative and positive groups and the results obtained by enzyme-linked immunosorbent assays (ELISA) assays were compared with the number of worms counted and the IgG titers at different times of infection. RESULTS: Data showed that ELISA using adult worm antigens (ELISA-SWAP) presented a satisfactory correlation between the absorbance value of IgG titers and the individual number of worms counted after perfusion technique (R²=0.62). In addition, ELISA-SWAP differentially detected positive samples with 30 and 60 days post infection (p=0.011 and 0.003, respectively), whereas ELISA using egg antigens (ELISA-SEA) detected samples after 140 days (p=0.03). CONCLUSIONS: These data show that the use of different antigens in immunological methods can be used as potential tools for the analysis of the chronological evolution of S. mansoni infection in murine schistosomiasis. Correlations with human schistosomiasis are discussed.

Aedes aegypti eggs oviposited on water surface collected from field ovitraps in Nova Iguaçu City, Brazil

ABSTRACT INTRODUCTION: Aedes aegypti eggs can be collected from the water surface. METHODS: Aedes aegypti oviposition from 97 field ovitraps was studied. RESULTS: Of the 16,016 eggs collected, 11,439 were obtained from paddles in ovitraps and 4,577 from water. Further, 89 (91.8%) traps contained eggs on water and 22 (22.7%) traps contained eggs only on water. CONCLUSIONS: In field traps, Aedes aegypti females usually oviposit some eggs on water surface suggesting that they might also oviposit on water of some natural breeding, and this possibility needs to be investigated. Eggs oviposited on water need to be considered for collecting trap data.

Eggs and eggshells of Crocodylomorpha from the Upper Jurassic of Portugal

Crocodylomorph eggs are relatively poorly known in the fossil record when compared with skeletal remains, which are found all over the world, or when compared with dinosaur eggs. Herein are described crocodiloid eggshells from the Upper Jurassic Lourinhã Formation of Portugal, recovered from five sites: Cambelas (clutch), Casal da Rola, Peralta (eggshell fragments), and Paimogo North and South (three partial crushed eggs and eggshell fragments). The clutch of Cambelas, composed of 13 eggs, is the only sample not found in association with dinosaur eggshells. Morphological characters of the eggshells described herein, such as shell units and microstructure, are consistent with the crocodiloid morphotype. As such, this material is assigned to the oofamily Krokolithidae, making them the oldest known crocodylomorph eggs so far and the best record for eggs of non-crocodylian crocodylomorphs. Two new ootaxa are erected, Suchoolithus portucalensis oogen. et oosp. nov, for the clutch of Cambelas, and Krokolithes dinophilus, oosp. nov., for the remaining eggshells. The basic structure of crocodilian eggshells has remained stable since at least the Late Jurassic. Additionally, the findings suggest previously unknown biological associations with contemporary archosaurs, shedding light on the poorly understood egg morphology, reproduction strategies and paleobiology of crocodylomorphs during the Late Jurassic.

Report of the State board of agriculture on the work of extermination of the gypsy moth.

1898:Jan.