A Homemade Snare: An Alternative Method for Mechanical Removal of Dirofilaria Immitis in Dogs

Canine dirofilariosis is a life-threatening parasitic disease that is increasingly reported worldwide. Once diagnosed the main treatment goals are to improve the animal's clinical condition and to eliminate all life stages of the parasite with minimal posttreatment side effects. This can be achieved through mechanical, surgical, or chemotherapeutical approaches. Currently, manual extraction is the preferred method to remove adult heartworms due to its diminished invasiveness, reduced damage to the vascular endothelium, and shortened anaesthesia duration. However, it remains an expensive technique that can be highly traumatic. To address this issue, a nontraumatic homemade catheter-guided snare was developed for heartworm removal by adapting and folding a 0.014-inch coronary wire (BMW, Abbott Vascular). Transvenous heartworm extraction was performed on a dog severely infected with adult heartworms by inserting the modified snare into a 6-F Judkins right coronary guiding catheter BMW (Cordis) and advancing it into the right ventricle under fluoroscopic guidance. Fifteen adult specimens of Dirofilaria immitis were successfully extracted from the pulmonary artery and right ventricle without complications. To assure the death of both larvae and adults, postoperative treatment was successfully managed using ivermectin, doxycycline, and melarsomine, with no recurrence after surgery.

Trypanosomiasis cruzi: a follow-up study of tissue reacting immunoglobulins in infected purebred pinscher dogs

Antibodies against striated muscle (cardiac and skeletal) were studied in serum samples from 36 purebred prepubertal Pinscher dogs (15 Controls without infection and 21 infected with Trypanosoma cruzi from 7 to 400 days after infection with 1000 trypomastigotes/gram body weight of the Colombiana strain by the intraperitoneal route). Although three different immunohistological pattems of tissue-reacting immunoglobulins were found their presence was not correlated with any peculiar characteristics or with the severity of the disease in each particular dog.

Analysis of the use of fenthion via epicutaneous in dogs for Rhipicephalus sanguineus control

The action of fenthion was studied in a 15% epicutaneous formulation upon Rhipicephalus sanguineus, which may transmit pathogens to men and other animals, such as Ehrlichia, Babesia and Ricketsia. Dogs were artificially infected for the trial. The fenthion bioassays were begun four months after artificial infestation. The test group, having a mean of 186 ticks per dog, received the formulation dosage according to body weight on the neck region. Tick counts were performed, considering diameters > or = 2mm, during 11 days of treatment, in the most affected body areas: back, ears and paws. Before the application of fenthion in the dogs, it were observed an average 43.3% ticks in the ears, 38.1% in the back area and 17.6% in the paws. The number of ticks in dogs decreased by 36.2%, 63.8%, 82.7%, 67%, 40% and 4.9%, respectively on days 1, 2, 3, 5, 7, 9 and 11 after treatment. R. sanguineus anti-tick activity, lower than that officially recommended, was verified. The number of ticks increased progressively after the 5th day, demonstrating residual insecticide inefficacy. The results obtained did not indicate the use of this formulation, at the tested dosage, as an elective measure for R. sanguineus control.

QBC® for the diagnosis of human and canine american visceral leishmaniasis: preliminary data

"Quantitative Buffy Coat" (QBC®) is a direct and fast fluorescent method used for the identification of blood parasites. Since Leishmania chagasi circulates in blood, we decided to test it in American visceral leishmaniasis (AVL). Bone marrow (BM) and peripheral blood (PB) of 49 persons and PB of 31 dogs were analyzed. QBC® was positive in BM of 11/11 patients with AVL and in 1/6 patients with other diseases. Amastigotes were identified in PB of 18/22 patients with AVL and in none without AVL. The test was positive in 30 out of the 31 seropositive dogs and in 28/28 dogs with Leishmania identified in other tissues. QBC® is a promising method for diagnosis of human AVL, and possibly for the exam of PB of patients with AVL/AIDS, for the control of the cure and for the identification of asymptomatic carriers. Because it is fast and easy to collect and execute, QBC® should be evaluated for programs of reservoir control.

Toxoplasma antibody and stool parasites in public school children, Rolândia, Paraná, Brazil

The occurrence of toxoplasmosis and enteroparasitosis was studied in 434 children from elementary schools in the rural and urban areas of Rolândia, Paraná State, Brazil. Sera and fecal samples from all the students were submitted to IFA for Toxoplasma gondii and coproparasitological tests, respectively. The children were tested by Amsler grid and 72 of them were examined for the presence of lesions compatible with ocular toxoplasmosis. Some variables were tested but none showed increased risk for toxoplasmosis. The distribution according to sex and age and also same other variables are presented and discussed. Correlations between Amsler's grid test, toxoplama RIFI, occurrence of eyes lesions and enteroparasitosis are also considered.

Comparison of Trypanosoma cruzi infection in dogs inoculated with blood or metacyclic trypomastigotes of Berenice-62 and Berenice-78 strains via intraperitoneal and conjunctival routes

This paper aimed to verify the influence of the inoculum source (blood or metacyclic trypomastigote) and the route of inoculation (intraperitoneal or conjunctival) on the course of T. cruzi infection in dogs, using comparatively the T. cruzi strains Berenice-62 and Berenice-78. All dogs inoculated intraperitoneally became infected independently of the T. cruzi strain and source of trypomastigotes used. High level of infectivity was also observed when metacyclic trypomastigotes of both strains were inoculated by conjunctival route. However, when blood trypomastigotes were inoculated by conjunctival route the percentages of infectivity were significantly lower in dogs inoculated with both strains. Parasitaemia was significantly higher in animals infected with metacyclic trypomastigotes via the conjunctival route independently of the T. cruzi strain used. All animals infected with Berenice-78 strain showed severe acute myocarditis. On the other hand, animals infected with Berenice-62 showed severe acute myocarditis only when infected with metacyclic trypomastigote, via the intraperitoneal route. The results suggest that the source of the inoculum and the route of inoculation remarkably influence the evolution of the infection for the T. cruzi in the vertebrate host even when the same strain of the parasite is used.

Interaction of malaria parasites with host late endocytic and autophagic pathways is essential for Plasmodium liver stage development

RESUMO: A Malária é causada por parasitas do género Plasmodium, sendo a doença parasitária mais fatal para o ser humano. Apesar de, durante o século passado, o desenvolvimento económico e a implementação de diversas medidas de controlo, tenham permitido erradicar a doença em muitos países, a Malária continua a ser um problema de saúde grave, em particular nos países em desenvolvimento. A Malária é transmitida através da picada de uma fêmea de mosquito do género Anopheles. Durante a picada, os esporozoítos são injetados na pele do hospedeiro, seguindo-se a fase hepática e obrigatória do ciclo de vida. No fígado, os esporozoítos infetam os hepatócitos onde se replicam, dentro de um vacúolo parasitário (VP) e de uma forma imunitária silenciosa, em centenas de merozoitos. Estas novas formas do parasita são as responsáveis por infetar os eritrócitos, iniciando a fase sanguínea da doença, onde se os primeiros sintomas se manifestam, tais como a característica febre cíclica. A fase hepática da doença é a menos estudada e compreendida. Mais ainda, as interações entre o VP e os organelos da células hospedeira estão ainda pouco caracterizados. Assim, neste estudo, as interações entre os organelos endocíticos e autofágicos da célula hospedeira e o VP foram dissecados, observando-se que os anfisomas, que são organelos resultantes da intersecção do dois processos de tráfego intracelular, interagem com o parasita. Descobrimos que a autofagia tem também uma importante função imunitária durante a fase hepática inicial, ao passo, que durante o desenvolvimento do parasita, já numa fase mais tardia, o parasita depende da interação com os endossomas tardios e anfisomas para crescer. Vesiculas de BSA, EGF e LC3, foram, também, observadas dentro do VP, sugerindo que os parasitas são capazes de internalizar material endocítico e autofágico do hospedeiro. Mais ainda, mostramos que esta interação depende da cinase PIKfyve, responsável pela conversão do fosfoinositidio-3-fosfato no fosfoinositidio-3,5-bifosfato, uma vez que inibindo esta cinase o parasita não é capaz de crescer normalmente. Finalmente, mostramos que a proteína TRPML1, uma proteína efetora do fosfoinositidio-3,5-bifosfato, e envolvida no processo de fusão das membranas dos organelos endocíticos e autofágicos, também é necessária para o crescimento do parasita. Desta forma, o nosso estudo sugere que a membrana do VP funde com vesiculas endocíticas e autofágicas tardias, de uma forma dependente do fositidio-3,5-bifosfato e do seu effetor TRPML1, permitindo a troca de material com a célula hospedeira. Concluindo, os nossos resultados evidenciam que o processo autofágico que ocorre na célula hospedeira tem um papel duplo durante a fase hepática da malaria. Enquanto numa fase inicial os hepatócitos usam o processo autofágico como forma de defesa contra o parasita, já durante a fase de replicação o VP funde com vesiculas autofágicas e endocíticas de forma a obter os nutrientes necessários ao seu desenvolvimento.--------- ABSTRACT: Malaria, which is caused by parasites of the genus Plasmodium, is the most deadly parasitic infection in humans. Although economic development and the implementation of control measures during the last century have erradicated the disease from many areas of the world, it remains a serious human health issue, particularly in developing countries. Malaria is transmitted by female mosquitoes of the genus Anopheles. During the mosquito blood meal, Plasmodium spp. sporozoites are injected into the skin dermis of the vertebrate host, followed by an obligatory liver stage. Upon entering the liver, Plasmodium parasites infect hepatocytes and silently replicate inside a host cell-derived parasitophorous vacuole (PV) into thousands of merozoites. These new parasite forms can infect red blood cells initiating the the blood stage of the disease which shows the characteristic febrile malaria episodes. The liver stage is the least characterized step of the malaria infection. Moreover, the interactions between the Plasmodium spp. PV and the host cell trafficking pathways are poorly understood. We dissected the interaction between Plasmodium parasites and the host cell endocytic and autophagic pathways and we found that both pathways intersect and interconnect in the close vicinity of the parasite PV, where amphisomes are formed and accumulate. Interestingly, we observed a clearance function for autophagy in hepatocytes infected with Plasmodium berghei parasites at early infection times, whereas during late liver stage development late endosomes and amphisomes are required for parasite growth. Moreover, we found the presence of internalized BSA, EGF and LC3 inside parasite vacuoles, suggesting that the parasites uptake endocytic and autophagic cargo. Furthermore, we showed that the interaction between the PV and host traffic pathways is dependent on the kinase PIKfyve, which converts the phosphoinositide PI(3)P into PI(3,5)P2, since PIKfyve inhibition caused a reduction in parasite growth. Finally, we showed that the PI(3,5)P2 effector protein TRPML1, which is involved in late endocytic and autophagic membrane fusion, is also required for parasite development. Thus, our studies suggest that the parasite parasitophorous vacuole membrane (PVM) is able to fuse with late endocytic and autophagic vesicles in a PI(3,5)P2- and TRPML1-dependent manner, allowing the exchange of material between the host cell and the parasites, necessary for the rapid development of the latter that is seen during the liver stage of infection. In conclusion, we present evidence supporting a specific and essential dual role of host autophagy during the course of Plasmodium liver infection. Whereas in the initial hours of infection the host cell uses autophagy as a cell survival mechanism to fight the infection, during the replicative phase the PV fuses with host autophagic and endocytic vesicles to obtain nutrients required for parasite growth.

Detection of Cryptosporidium spp and other intestinal parasites in children with acute diarrhea and severe dehydration in Rio de Janeiro

The objective of the present study was to estimate the frequency of infection by Cryptosporidium spp and other intestinal parasites in dehydrated children with gastroenteritis who were admitted to a pediatric hospital. Stool examinations from 218 children were performed. Cryptosporidium spp was identified in eighteen out of 193 stool samples (9.3%) subjected to safranin-methylene blue staining. Giardia lamblia was detected in ten out of 213 (4.7%) samples examined via the direct or Ritchie methods. Other parasites identified were Ascaris lumbricoides (4.2%), Blastocystis hominis (1.4%), Entamoeba coli (0.9%), Entamoeba histolytica/Entamoeba dispar (0.5%), Endolimax nana (0.5%), Trichuris trichiura (0.5%) and Enterobius vermicularis (0.5%).

Frequency of Blastocystis hominis and other intestinal parasites in stool samples examined at the Parasitology Laboratory of the School of Pharmaceutical Sciences at the São Paulo State University, Araraquara

Blastocystis homins is a protozoan that causes an intestinal infection known as human blastocystosis. This infection is diagnosed by means of parasitological examination of stools and by permanent staining techniques. The present study was developed to evaluate the frequency of Blastocystis hominis infection among inhabitants of the Araraquara region, State of São Paulo, and to compare different methods for investigating this protozoan in feces samples. Evaluations on 503 stool samples were performed by means of direct fresh examination and using the techniques of Faust et al., Lutz and Rugai et al. In addition, the iron hematoxylin, trichrome and modified Kinyoun staining techniques were used. Out of the 503 samples examined, 174 (34.6%) were found to be positive for the presence of intestinal parasites. The most frequent protozoa and helminths were Entamoeba coli (14.6%) and Strongyloides stercoralis (6.7%), respectively. Blastocystis hominis was present in 23 (4.6%) fecal samples, with a predominately pasty consistency and without characterizing a condition of diarrhea. Despite the low frequency of Blastocystis hominis found in the Araraquara region, compared with other regions of Brazil, it is important to perform laboratory diagnostic tests for this protozoan. Its finding in fecal material is indicative of food and drinking water contamination. Since the transmission route for this parasite is accepted to be oral-fecal, this implies that the population needs guidance regarding hygiene and basic sanitation measures as a means for controlling health problems caused by enteroparasites.

Wearable monitoring system for assistance dogs

Despite the recent progresses in robotics, autonomous robots still have too many limitations to reliably help people with disabilities. On the other hand, animals, and especially dogs, have already demonstrated great skills in assisting people in many daily situations. However, dogs also have their own set of limitations. For example, they need to rest periodically, to be healthy (physically and psychologically), and it is difficult to control them remotely. This project aims to “augment” the Assistance dog, by developing a system that compensates some of the dog weaknesses through a robotic device mounted on the dog harness. This specific study, involved in the COCHISE project, focuses on the development of a system for the monitoring of dogs activity and physiological parameters.

Prevalence of intestinal parasites in preschool children in the region of Uberlândia, State of Minas Gerais, Brazil

INTRODUCTION: Children are an important high-risk group for helminth and protozoa infections. Daycare centers are environments where children have proven to be more susceptible to acquiring intestinal parasites. Thus, the purpose of this study was to verify the prevalence of intestinal parasites in children who attended the two daycare centers maintained by the local government of Uberlândia, State of Minas Gerais, Brazil. METHODS: Fecal samples were collected from 133 children (73 children at the Public Preschool for Early Childhood Education, PPECE A, and 60 at the PPECE B) following identification according to sex and age and agreement to participate by parents or guardians who signed the free, informed consent form. The samples were examined by the Lutz method. RESULTS: Coproparasitological tests performed on 133 children showed that 29.3% of them were parasitized for enteroparasites or commensals, 6.7% of the children presented polyparasitism. Among the protozoa, Giardia lamblia were the most prevalent and Hymenolepis nana were the most frequent among the helminths. CONCLUSIONS: Thus, analysis of the results showed that intestinal parasites still represent a public health problem, especially among children and in areas where the socioeconomic and educational conditions are less favorable.

Evaluation of Leishmania (Leishmania) chagasi strains isolated from dogs originating from two visceral leishmaniasis-endemic areas in Brazil using multilocus enzyme electrophoresis

INTRODUCTION: Domestic dogs are the most important reservoir in the peridomestic transmission cycle of Leishmania (Leishmania) chagasi. The genetic variability of subpopulations of this parasite circulating in dogs has not been thoroughly analyzed in Brazil, even though this knowledge has important implications in the clinical-epidemiological context. METHODS: The objective of this study was to evaluate and compare the phenotypic variability of 153 L. chagasi strains isolated from dogs originating from the municipalities of Rio de Janeiro (n = 57) and Belo Horizonte (n = 96), where the disease is endemic. Strains isolated only from intact skin were selected and analyzed by multilocus enzyme electrophoresis using nine enzyme systems (6PG, GPI, NH1 and NH2, G6P, PGM, MDH, ME, and IDHNADP). RESULTS: The electrophoretic profile was identical for all isolates analyzed and was the same as that of the L. chagasi reference strain (MHOM/BR/74/PP75). Phenetic analysis showed a similarity index of one for all strains, with the isolates sharing 100% of the characteristics analyzed. CONCLUSIONS: The results demonstrate that the L. chagasi populations circulating in dogs from Rio de Janeiro and Belo Horizonte belong to a single zymodeme.