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Demands for effective vaccines to control parasitic diseases of humans and livestock have been recently exacerbated by the development of resistance of most pathogenic parasites to anti-parasitic drugs. Novel genomic and proteomic technologies have provided opportunities for the discovery and improvement of DNA vaccines which are relatively easy as well as cheap to fabricate and stable at room temperatures. However, their main limitation is rather poor immunogenicity, which makes it necessary to couple the antigens with adjuvant molecules. This paper review recent advances in the development of DNA vaccines to some pathogenic protozoa and helminths. Numerous studies were conducted over the past 14 years of 21st century, employing various administration techniques, adjuvants and new immunogenic antigens to increase efficacy of DNA vaccines. Unfortunately, the results have not been rewarding. Further research is necessary using more extensive combinations of antigens; alternate delivery systems and more efficient adjuvants based on knowledge of the immunomodulatory capacities of parasitic protozoa and helminths. [ABSTRACT FROM AUTHOR]

Giardia intestinalis is a complex species divided into 7 assemblages (A - G). Two of them (A and B) are infective for both humans and animals. In cats four assemblages can occur: A, B, D, and F Assemblages A and B infect either cats, dogs and humans, assemblage D infects cats and dogs and assemblage F only cats. The purpose of this study was to determine the prevalence and genotypes of G. intestinalis in cats from Warsaw. From November 2006 to March 2007 a hundred sixty samples of stool were collected and examined by light microscopy. G. intestinalis cysts were detected in 3.75% of samples. DNA extracted from positive samples was used as template for PCR-RFLP using Giardia specific primers and the amplicons were sequenced. A comparison of the obtained DNA sequences with the Giardia sequences in the GeneBank database revealed assemblage A in 1.25% of the investigated cats, assemblage B in 1.25% and D in 1.25%.

The aim of this work was to develop a PCR assay for the detection of F. hepatica in Galba truncatula snails and to evaluate its performance in field studies. Primers were designed to amplify a 124bp non-coding tandem repeat found in the Fasciola genome. The result was a banding pattern corresponding to multiples of the initial target sequence. The sensitivity of the PCR was determined on experimentally infected snails. The test was sensitive enough to detect fluke DNA in snails experimentally infected with 1 miracidium, within 12h after exposure. The specificity was determined with Dicrocoelium dendriticum, Paramphistomum cervi and snail DNA. No cross-reactions occurred with DNA of the trematodes or snail DNA. G. truncatula specimens were collected from 4 localities in Eastern Poland, with a total of 192 snails from 12 habitats. The overall prevalence of F. hepatica infection was 26.6% (51/192), ranging from 21.4% to 84.6% in the individual sites. The designed assay was shown to be a valuable epidemiological tool for the purpose of snail infection monitoring. The results on F. hepatica prevalence in snail hosts are the first data from Poland since the 1950s and the only such data based on molecular methods.

The purpose of this study was to specify the occurrence and prevalence of Babesia microti in hard ticks removed from dogs in Warsaw (central Poland). Among 590 collected ticks, 209 were identified as Ixodes ricinus, and 381 as Dermacentor reticulatus. B. microti DNA was detected in 11 out of 590 (1.86%) samples of ticks. The DNA of the parasite was detected only in lysates from female I. ricinus ticks (11 out of 193; 5.7%). The result of this study is the first evidence of B. microti in I. ricinus ticks in Warsaw.

The purposes of this study were to specify the occurrence and prevalence of Babesia canis, Borrelia burgdorferi sensu lato, and Anaplasma phagocytophilum in ticks removed from dogs in Warsaw, and to determine the Borrelia species occurring in Ixodes ricinus ticks. Among 590 collected ticks, 209 were identified as I. ricinus, and 381 as Dermacentor reticulatus. DNA of B. canis was detected in 11% of D. reticulatus ticks. We found that 6.2% of I. ricinus ticks harbored B. burgdorferi s.l. specific DNA and 2.9% harbored A. phagocytophilum DNA. In these samples sequencing of the detected Borrelia amplicon confirmed infection with Borrelia afzelii genospecies. New sequences were submitted to the GenBank database (accession no. EU152128, EU152127, EU152126). This work is the first detection of B. afzelii and A. phagocytophilum in ticks from Warsaw, and the first survey for the prevalence of B. canis, B. afzelii, and A. phagocytophilum in ticks in central Poland.

In the presented study we evaluated the hematological changes in samples of blood obtained from 248 dogs naturally infected with large Babesia. The evaluation included red blood cell count, hemoglobin concentration, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), leucocyte counts, thrombocyte counts, mean platelet volume (MPV), morphology of erythrocytes and leucogram. The most common disorders in affected dogs were thrombocytopenia and anisocytosis. The count of erythrocytes below reference values was detected in 26.2% of dogs and 31.4% of affected animals presented hematocrit below the reference values. Hemoglobin concentration below the reference values was noted in 29% of dogs, an increase of MCHC above normal values was detected in 21% of examinated dogs and MCV below normal values was recognized in 2% of dogs. 60.5% of dogs presented anisocytosis, 25% poikilocytosis, 23.8% polychromasia, 19.7% hypochromia and 4.4% erythroblastosis. Thrombocytopenia was detected in 99.5% of dogs, but only 15.3% of examined animals showed increase of MPV, which suggests a response of the bone marrow. 36.3% of dogs had neutropenia, and 21.8% presented a left shift, 14.9% had the lymphocytosis and 7.2% lymphopenia.

The aim of the study was to evaluate an influence of vaccination of the final host on F. hepatica development in intermediate hosts. Fluke eggs were isolated from the biliary tracts of calves vaccinated orally with recombinant cysteine proteinase of F. hepatica after the challenge infection and from control calves which received the infection only. To asses the effect of the vaccine on egg "hatch rate" the eggs were transferred to the Petri dishes with distilled water and incubated at 25 degrees C for 16-19 days. They were subsequently exposed to light for about 2 h, at a temperature of 27 +/- 1 degrees C, to stimulate sprouting of the miracidia and asses the egg hatchability. In order to evaluate infectivity and pathogenicity of the miracidia, single miracidium infections of Lymnea truncatula by F. hepatica were carried out under laboratory conditions using 4-mm-high snails. The prevalence of snail infections with F. hepatica was calculated using the ratio between the number of cercariae-shedding snails in each group and that of surviving snails. It appeared that the eggs isolated from immunized calves demonstrated significantly lower hatchability than the eggs isolated from non-vaccinated control hosts. Also, the proportion of infected snails as well as their mortality were lower after exposition to miracidia originating from vaccinated calves. It is suggested that effectors of the immune response in vaccinated calves inhibited in part biological activity of cysteine proteinases of the fluke which are known to be involved in egg shell formation, penetration of host's tissues and worm feeding.

Introduction: Giardia intestinalis is the most common intestinal protozoan parasite, which infects humans, dogs and other mammals throughout the world. So far eight genotypes of the parasite have been described of which four were found in dogs. Assemblages A-I and B infect either dogs or humans. Assemblages C and D occur only in dogs. The aim of the study was to determine the prevalence and genotypes of G. intestinalis in domestic dogs of Warsaw area., Material and Methods: From October 2005 to March 2006 fecal samples were collected from 350 dogs and examined using light microscopy and PCR techniques., Results: 5.14% of dogs was found to be positive for G. intestinalis by microscopy and prevalence of 9.14% was found by PCR. The PCR amplicons were sequenced and the DNA sequences were compared with Giardia sequences in GeneBank database. The analysis revealed assemblage A-I in 1.71% of dogs, assemblage C in 1.14% and assemblage D in 6.28% of dogs in Warsaw. According to literature, the genotype A can infect humans however a role of dogs as a reservoir of human giardiosis in Poland is not known.

Ticks are known as a vector of many viral, bacterial, rickettsial and protozoan infections of dogs. The threat with particular tick-transmitted disease depends very much on the tick species which feeds on the dog. In this paper we present results of research designed to identify tick species which attack dogs in the Warsaw area. Ticks were collected from dogs presented for medical examination in veterinary clinics in different parts of Warsaw. All of 590 tick specimens found on dogs belonged to the family Ixodidae (hard ticks). The majority (64.6 %) of the collected ticks were identified as Dermacentor reticulatus--vector of Babesia canis. The other tick species found on examined dogs was Ixodes ricinus. The male to female ratio was more than 3 times higher in D. reticulatus than in I. ricinus.

The potential tertiary structure of Ancylostoma ceylanicum cysteine proteinase was obtained by Automatic Program 3D-JIGSAW and used for finding homologues of known structure by VAST program. The results of computational analysis showed the presence of domains recognizing host immunoglobulins. Based on this analysis we suggest that this protein is involved in cleaving of host antibodies and therefore it may be promising vaccine candidate. In this paper we present the computational analysis of parasitic antigen which is very helpful in evaluation of the potential role of this protein.

Hookworms are very important blood sucking nematode parasites of humans and domestic animals. The host with a heavy infection can lose almost a cup of blood per day. This may contribute to anemia which is associated with many physical and mental developmental insults. The works on obtaining an effective hookworm vaccine have been lasting for about eighty years. Recent identifications of a number of bioactive molecules produced by larval and adult stages of Ancylostomatidae are very helpful for selecting of nematode proteins crucial for host-parasite interactions and promising vaccine antigens. Many of these molecules are involved in host skin penetration by infective larvae, intestinal tissue invasion and digestion of haemoglobin and/or other macromolecular substrates. However, the results of many vaccination trials using recombinant forms of these proteins showed no sufficient protection against experimental hookworm infections.