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PubMed2005

Innate cell-mediated immune response and peripheral leukocyte populations in Atlantic salmon, Salmo salar L., to a live Cryptobia salmositica vaccine.

The effects of a live Cryptobia salmositica (Kinetoplastida) vaccine on the humoral and cellular immune response, and changes in the peripheral leukocyte populations of Salmo salar were investigated. The vaccine produced detectable parasitemia in the blood which peaked at 5 weeks post-vaccination (w.p.v). Antibodies were detectable at 4 w.p.v. and the antibody titer increased as parasitemia declined. Respiratory burst activity in vaccinated fish was significantly higher than in control fish; the highest activity occurred with rising parasitemia and lower activity with declining parasitemia. There was a significant increase in the proportion of granulocytes (to total leukocytes) at 4 w.p.v. At 6 w.p.v., the proportion of lymphocytes and monocytes increased significantly and remained elevated. These results demonstrate innate (respiratory burst activity and an increase in the proportion of granulocytes corresponding to rising parasitemia) and adaptive (antibody production and increases in the proportion of monocytes and lymphocytes corresponding to declining parasitemia) immune responses to the live vaccine.

Animals↗
PubMed1995

Efficacy of a live Cryptobia salmositica vaccine, and the mechanism of protection in vaccinated rainbow trout, Oncorhynchus mykiss, against cryptobiosis.

An attenuated strain of Cryptobia salmositica was used as a live vaccine to protect rainbow trout, Oncorhynchus mykiss, against cryptobiosis. Fish immunized with 1.0 x 10(4) or 5.5 x 10(4) attenuated C. salmositica per fish were protected 3 weeks after immunization; however, this period was reduced to 2 weeks if fish were vaccinated with 1.0 x 10(5) attenuated parasites per fish. Fish were still protected at 6, 12 and 24 months after vaccination. Complement fixing antibodies in the blood of immunized fish lysed C. salmositica under in vitro conditions. The titre of complement fixing antibodies in vaccinated fish increased rapidly 1-2 weeks post-challenge. In vitro phagocytosis was enhanced by antiserum and by activated macrophages from vaccinated fish. There was also evidence of antibody independent and antibody dependent cell-mediated cytotoxicity in vaccinated fish.

Animals↗
PubMed2005

Comparison of the specificity and sensitivity of PCR, nested PCR, and real-time PCR for the diagnosis of histomoniasis.

Blackhead, also known as enterohepatitis, is caused by a protozoan parasite called Histomonas meleagridis. Clinical symptoms are nonspecific. Until now, diagnosis has been mainly based on postmortem lesions and microscopical and histopathological examination. In many cases, especially in layer flocks, these conventional methods are not sufficient, as the lesions are sometimes not clear. The technique for isolation of histomonads in vitro offers many advantages, but the confirmation of histomonads growing in culture may require a time-consuming procedure of rectal inoculation of culture material into chickens or turkeys. The aim of our investigation was to establish a conventional polymerase chain reaction (PCR), a nested PCR, and a real-time PCR, and to examine their specificity as well as sensitivity in the diagnosis of histomoniasis. The obtained results have shown that the conventional PCR is more sensitive than the real-time PCR. Furthermore, the sensitivity of the PCR can be increased by adding the nested PCR. However, the real-time PCR is more specific.

Amino Acid Sequence↗
PubMed1998

Characterization of a 200 kDa glycoprotein (Cs-gp200) on the pathogenic piscine haemoflagellate Cryptobia salmositica.

The 200 kDa antigenic doublet of the pathogenic haemoflagellate Cryptobia salmositica Katz, 1951, was detected using a monoclonal antibody (MAb-001) in 1-dimensional SDS-PAGE. This antigenic doublet is a glycoprotein since it was susceptible to both protease K and to sodium m-periodate oxidation and is designated Cs-gp200. It has a PI (isoelectric point) value of about 5.5 (using 2-dimensional gel electrophoresis). It migrated faster under reducing conditions than under nonreducing conditions and was partitioned into the aqueous phase in Triton X-114 phase separation. It is a secretory-excretory product since it was detected in a non-protein culture medium with C. salmositica. These results suggest that the Cs-gp200 is a glycoprotein consisting of carbohydrate determinants and conformational polypeptide with internal disulphide bonds. It is a hydrophilic antigen, is a secretory product of the parasite, and plays a important role in antibody elicitation in immunized fish.

Animals↗
PubMed1996

Identification of a misleading trypanosomatid parasite from Gerbillus pyramidum and G. andersoni in a Leishmania major endemic area in north Sinai.

During an epidemiologic investigation of cutaneous leishmaniasis at a focus in north Sinai, Egypt, between June 1989 and December 1991, 897 desert rodents were trapped and examined to identify reservoir hosts for Leishmania major. Mixed forms of epimastigotes and promastigotes were isolated in Tanabe's medium from 4 Gerbillus pyramidum and 1 Gerbillus andersoni. The 2 forms were later grown and separated as distinct cultures in Schneider's medium. The isoenzyme profile of the gerbils' promastigotes was identical to Leishmania tropica but differed from those of L. major and the gerbils' epimastigotes. The protein pattern by sodium dodecyl sulfate poly acrylamide gel electrophoresis gave no conclusive results. The Hae III restriction endonuclease analysis of kinetoplast DNA of both morphological forms confirmed their similarity and distinguished them from L. tropica and L. major. The gerbils' promastigotes were 30% broader, with a smaller nucleus than those of L. tropica. Following several subcultures, epimastigotes were found to transform to promastigotes. These observations suggest that the 2 forms belong to the genus Trypanosoma. Further studies are in progress to classify this putative Trypanosoma species whose promastigote stages display isoenzyme patterns identical to L. tropica, and which can be misidentified microscopically as Leishmania promastigotes.

Animals↗
PubMed1996

Acid phosphatase in the pathogenic and nonpathogenic hemoflagellates, Cryptobia spp., of fishes.

Acid phosphatase (ACP) was detected in whole-cell lysates, membrane-bound and water-soluble fractions of Cryptobia salmositica (pathogenic and nonpathogenic vaccine strains), Cryptobia bullocki, and Cryptobia catostomi using p-nitro-phenylphosphate as the substrate. High activities were in acidic pH (3.0-5.5) and the optimal pH was 5.0 Highest ACP activity was in the membrane-bound fraction. The pathogenic strain of C. salmositica had significantly higher total ACP activity than the vaccine strain and the other 2 species. However, the activity in the pathogenic C. salmositica decreased significantly with prolonged in vitro cultivation. The membrane-bound ACP of the pathogenic C. salmositica had highest resistance to the ACP inhibitor, sodium tartrate.

Acid Phosphatase↗
PubMed2005

Decreased level of novelty seeking in blood donors infected with Toxoplasma.

OBJECTIVES: Toxoplasma gondii, a parasitic protozoan, infects about 30 - 60% of people worldwide. Toxoplasma is known to induce behavioral changes and an increase of dopamine in mice. The presence of anti-Toxoplasma antibodies (latent toxoplasmosis) is also a risk factor for schizophrenia. Latent toxoplasmosis in men (male soldiers) is associated with lower novelty seeking. As the novelty seeking is supposed to negatively correlate with level of dopamine, the observed effect was interpreted as indirect evidence of increased dopamine levels in subjects with toxoplasmosis. However, it is also possible that the observed effect was caused by association of both novelty seeking and Toxoplasma infection with a third factor, e.g. size of place of residence. METHODS: Personality profile of 290 blood donors (205 men and 85 women) were measured by Cloninger's TCI (Temperament and Character Inventory) and their blood samples were assayed for the presence of anti-Toxoplasma antibodies. Difference between Toxoplasma-infected and Toxoplasma-free subjects was tested with ANCOVA method with gender, size of place of residence, and age as covariates. RESULTS: The present analysis revealed that lower novelty seeking was associated with latent toxoplasmosis both in men and women. The effect of infection on novelty seeking remained significant even after adjustment for size of place of residence (p<0.01). CONCLUSION: Decreased novelty seeking in Toxoplasma-infected subjects have been already confirmed in three independent populations (male soldiers and male and female blood donors). These findings suggest that the local inflammation-induced increase in dopamine in the brain of infected subjects can represent a missing link between toxoplasmosis and schizophrenia.

Adult↗
PubMed2002

Serological levels of zinc, copper and iron elements among Giardia lamblia infected children in Turkey.

BACKGROUND: Giardiasis, an intestinal protozoan infection caused by Giardia lamblia, is common in Turkey, especially among children aged between 2- and 14-years-old. Effects of giardiasis on serological levels of zinc, copper and iron elements were assessed in this study. METHODS: A total of 45 children, aged between 2- and 14-years-old, who were admitted to the Pediatrics Department of Celal Bayar University Medical School with gastrointestinal complaints and diagnosed as having giardiasis by stool examinations in the Parasitology Department, were enrolled as the study group (SG). The control group (CG) consisted of 45 age-matched healthy children. Serological levels of zinc, copper and iron were measured by atomic absorption spectrophotometer in all samples. RESULTS: As a result of the study, serum zinc levels were 67.43 +/- 17.72 microg/dL and 145.20 +/- 9.13 microg/dL, copper levels were 198.45 +/- 39.14 microg/dL and 150 +/- 21.14 microg/dL and iron levels were 87.98 +/- 18.31 microg/dL and 160.45 +/- 45.40 microg/dL, in SG and CG, respectively. When compared separately as SG and CG, there was a statistically significant difference between the serological levels of all these elements. CONCLUSION: These results revealed that giardiasis increased the serological levels of copper, like other infectious agents. However, zinc and iron levels decreased during giardiasis due to malabsorption.

Adolescent↗
PubMed1999

Prevention of transfusional Trypanosoma cruzi infection in Latin America.

Trypanosoma cruzi is a protozoan infection widely spread in Latin America, from Mexico in the north to Argentina and Chile in the south. The second most important way of acquiring the infection is by blood transfusion. Even if most countries of Latin America have law/decree/norms, that make mandatory the screening of blood donors for infectious diseases, including T. cruzi (El Salvador and Nicaragua do not have laws on the subject), there is usually no enforcement or it is very lax. Analysis of published serologic surveys of T. cruzi antibodies in blood donors done in 1993, indicating the number of donors and screening coverage for T. cruzi in ten countries of Central and South America indicated that the probability of receiving a potentially infected transfusion unit in each country varied from 1,096 per 10,000 transfusions in Bolivia, the highest, to 13.02 or 13.86 per 10,000 transfusions in Honduras and Venezuela respectively, where screening coverage was 100%. On the other hand the probability of transmitting a T. cruzi infected unit was 219/10,000 in Bolivia, 24/10,000 in Colombia, 17/10,000 in El Salvador, and around 2-12/10,000 for the seven other countries. Infectivity risks defined as the likelihood of being infected when receiving an infected transfusion unit were assumed to be 20% for T. cruzi. Based on this, estimates of the absolute number of infections induced by transfusion indicated that they were 832, 236, and 875 in Bolivia, Chile and Colombia respectively. In all the other countries varied from seven in Honduras to 85 in El Salvador. Since 1993, the situation has improved. At that time only Honduras and Venezuela screened 100% of donors, while seven countries, Argentina, Colombia, El Salvador, Honduras, Paraguay, Uruguay and Venezuela, did the same in 1996. In Central America, without information from Guatemala, the screening of donors for T. cruzi prevented the transfusion of 1,481 infected units and the potential infection of 300 individuals in 1996. In the same year, in seven countries of South America, the screening prevented the transfusion of 36,017 infected units and 7, 201 potential cases of transfusional infection.

Chagas Disease↗
PubMed2004

HIV-1 vaccines and co-infection.

Vaccines are an economically efficient means of controlling viral infections, and it is likely that a vaccine against HIV-1 will be the most effective way of controlling the global AIDS crisis. However, an effective vaccine has not yet been attainable and in developing countries co-infection with protozoa and other chronic diseases adds another level of complexity to the design of an HIV-1 vaccine. Helminthic and protozoan infections can result in a constant state of immune activation that is characterised by a dominant T helper (Th)2 type of cytokine profile. Such an immune profile is likely to have an adverse impact on the efficacy of an HIV-1 vaccine CD8 cellular immune response and the corresponding Th1 cytokines that are most likely to be important for clearing viral infections.

AIDS Vaccines↗
PubMed1994

Experimentally induced intravaginal Tritrichomonas foetus infection in the estrogenized mouse.

Studies were initiated to establish and maintain intravaginal Tritrichomonas foetus infections in female BALB/c mice as a model for elucidation of parasite and host factors that affect the course of vaginal protozoan infections. Results of these studies indicated that T. foetus infections could only be established in mice in which estrus was induced and maintained. Over a period of several weeks, mice induced to estrus by weekly administration of estradiol cypionate exhibited purulent vaginal discharge and perivulvar abscesses. Implantation of silastic tubing containing 15 micrograms of estradiol-17 beta proved effective in induction and maintenance of estrus and avoided the animal health problems associated with estradiol cypionate treatment. Results of quantitative experiments indicated that the duration of trichomonad infection was influenced by initial colonization of the vagina, i.e., mice with high numbers of vaginal trichomonads at 7 days after infection maintained infections longer than did mice with lower numbers of vaginal parasites. Weekly administration of either 2 or 4 mg of methylprednisolone acetate to estrogenized mice did not extend the duration of T. foetus infections, thereby suggesting that the immune response did not limit the establishment and maintenance of primary vaginal trichomonad infections. Study of estrogenized BALB/c nu/nu mice supported these observations in that establishment of T. foetus infections was difficult in nu/nu mice and that, in most nu/nu mice (76%), the course of infection was not lengthened (mean, 1.9 weeks). When examined by electron microscopy, the earliest lesions were characterized by degeneration and necrosis of chondrocytes, along with degradation of cartilage matrix. These findings confirm that quinolone arthropathy develops in juvenile rabbits and is similar to quinolone arthropathy in other laboratory animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1999

Intestinal protozoa in HIV-infected patients in Apulia, South Italy.

Protozoa are important enteric pathogens in patients with human immunodeficiency virus (HIV) infection. In this study the prevalence of intestinal protozoa in 154 HIV-infected patients, with or without diarrhoea, in our region (Apulia, South Italy) was evaluated between December 1993 and February 1998. In the majority of patients CD4+ T cell count was below 200/microl. The overall prevalence of intestinal protozoa was 43/154 (27.92%). Twenty-eight (43.08%) out of 65 patients with diarrhoea and 15 (16-85%) out of 89 non-diarrhoeic patients were parasitized. In particular, in the group of 65 patients with diarrhoea the following protozoa were identified: Cryptosporidium parvum in 14 (21.54%), Blastocystis hominis in 7 (10.77%), microsporidia in 6 (9.23%), Giardia lamblia in 4 (6.15%) and Isospora belli in 1 (1.54%). Three patients were Cryptosporidium parvum-microsporidia co-infected. In patients without intestinal symptoms, prevalence was 3/89 (3.37%) for Cryptosporidium parvum, 9/89 (10.11%) for Blastocystis hominis, 1/89 (1.12%) for microsporidia and 2/89 (2.25%) for Giardia lamblia. A significant (P<0.001) correlation was observed between protozoan infection and the presence of diarrhoea. In particular, Cryptosporidium parvum and microsporidia infections were significantly (P<0.001) and P = 0.046, respectively) associated with diarrhoeal illness. Moreover, the majority of cases of cryptosporidiosis were first diagnosed in the periods of heaviest rainfall. Therefore, drinking water contamination may be a possible source of human infection in our area.

Adult↗