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F Jongejan

Publications and source records attributed to F Jongejan.

At least 19 recordsLinked to original sources
PubMed2003

A fatal case of human babesiosis in Portugal: molecular and phylogenetic analysis.

We report the first case of human babesiosis in Portugal. A 66-year-old splenectomized man was admitted to a Lisbon hospital after 1 week of fever, abdominal pain, anorexia and nausea. A high parasitaemia (30%) of Babesia parasites was found in Giemsa-stained blood smears and, despite treatment, the patient died several weeks later of renal failure. Ethylenediaminetetraacetic acid blood samples were processed for polymerase chain reaction (PCR) and reverse line blot hybridization to confirm and characterize the Babesia infection. The amplified PCR product was cloned and subsequently sequenced. Molecular analysis showed that the infection was caused by Babesia divergens and that other blood parasites were not involved. Phylogenetic analysis showed that the 18 S ribosomal RNA gene sequence was similar to three other European isolates of B. divergens. In view of the high risk for splenectomized individuals, strict measures should be taken to avoid tick bites.

Aged↗
PubMed2002

Seasonal epidemiology of ticks and aspects of cowdriosis in N'Dama village cattle in the Central Guinea savannah of Côte d'Ivoire.

In the Central Guinea savannah of Côte d'Ivoire, cattle breeding started only approximately 30 years ago. The impact of parasitism on the overall health status and productivity of the trypanotolerant N'Dama cattle in this area is unknown. In close collaboration with national veterinary institutions and local farmers, we studied spectrum, burden and seasonal dynamics of ticks (including aspects of cowdriosis) on N'Dama village cattle. In a longitudinal study, three randomly selected cattle herds (traditional farming type) of one village were examined repeatedly for ticks. Spectrum, burden, seasonal epidemiology of ticks were assessed. In these traditional herds (which lack (ecto)parasite management), all animals were infested by ticks at monthly counts. Five different tick species were identified; the four genera in order of frequency were: Amblyomma (overall prevalence 96%), Boophilus (47%), Hyalomma (<1%) and Rhipicephalus (<1%). Amblyomma variegatum was the most-abundant tick on cattle in all seasons. Seroprevalence of Cowdria ruminantium was 31% (95% CI: 26, 36%). Most of the animals typically carried low tick burdens. N'Dama cattle seem well adapted to their environment and can resist the tick burdens under this traditional farming system.

Animals↗
PubMed2002

Susceptibility of bovine umbilical cord endothelial cells to bovine herpesviruses and pseudocowpox virus.

The purpose of the study was to determine the susceptibility of bovine umbilical cord endothelial (BUE) cells to bovine herpesvirus (BHV) 1, BHV2, BHV4 and BHV5, and to pseudocowpox virus. The detection limits and growth curves of these viruses in BUE cells were compared with those in Vero, Madin-Darby bovine kidney (MDBK). or bovine fetal diploid lung (BFDL) cells. Detection limits were determined by inoculating cell cultures with serial 10-fold dilutions of these viruses, and growth curves by titration of virus, harvested at various times after infecting cells at a multiplicity of infection of 0.1. The detection limits of BHV2 and BHV4 were lower in BUE cells than in Vero or MDBK cells, and cytopathic effects were observed earlier in BUE cells. In addition, BHV2 and BHV4 grew to higher titres in BUE cells than in Vero or MDBK cells. BUE cells appeared to be equally susceptible to BHV5, but less susceptible to BHV1.1 and BHVI.2 than MDBK cells. The study showed that BUE cells are highly susceptible to BHV2 and BHV4. and that the use of BUE cells can improve the laboratory diagnosis of these viruses. The use of BUE cells could also improve the isolation and growth of pseudocowpox virus.

Animals↗
PubMed2001

Detection of haemoparasites in cattle by reverse line blot hybridisation with a note on the distribution of ticks in Sicily.

A reverse line blot hybridisation (RLB) of 21 oligonucleotides with polymerase chain reaction (PCR) amplified regions of 16S rRNA (Ehrlichia/Anaplasma group) or 18S rRNA (Babesia/Theileria group) genes of haemoparasites detected Theileria annulata, T. buffeli/orientalis, Babesia bovis, B. bigemina, B. divergens, Ehrlichia bovis, Anaplasma marginale, A. centrale and unknown species within the Rickettsia tribe.A very high prevalence of mixed infections was detected, which indicated that animals infected with Babesia spp. were also infected with Theileria spp. and/or Anaplasma spp. The tick distribution appeared to be seasonal with Hyalomma marginatum as the most frequently observed tick and Boophilus annulatus and Ixodes ricinus as the least frequently observed ticks. Other species identified in the 818 ticks collected during the five sampling periods between April 1998 and November 1999 included H. lusitanicum, Rhipicephalus sanguineus group, R. bursa, Dermacentor marginatus, Haemaphysalis punctata, B. annulatus and I. ricinus.

Anaplasma↗
PubMed2001

Dynamics of IgG1 and IgG2 subclass response in dogs naturally and experimentally infected with Ehrlichia canis.

Immunoglobulin (Ig) G subclasses were measured in dogs naturally and experimentally infected with Ehrlichia canis using enzyme-linked immunosorbant assay (ELISA). In this study, a higher IgG2 subclass response was noticed to natural and experimental E. canis infection in dogs. Anti-E. canis-IgG2 optic density (OD) values were found to be significantly higher than anti-E. canis-IgG1 during the different phases of the disease, and no differences in the IgG subclass responses to E. canis infection were found between symptomatic and asymptomatic dogs. Doxycycline treatment, which eliminated the rickettsia in three of four persistently infected dogs, had no noticeable influence on the E. canis-IgG subclass OD values during the treatment period. In order to facilitate the study, an ELISA for the detection of anti-E. canis IgG was developed and was shown to be sensitive and specific for E. canis-IgG, and in a significant correlation with the indirect immunofluorescence antibody test.

Animals↗
PubMed2001

Significance of serological testing for ehrlichial diseases in dogs with special emphasis on the diagnosis of canine monocytic ehrlichiosis caused by Ehrlichia canis.

Dogs are susceptible to a number of ehrlichial diseases. Among them, canine monocytic ehrlichiosis is an important and potentially fatal disease of dogs caused by the rickettsia Ehrlichia canis. Diagnosis of the disease relies heavily on the detection of antibodies and is usually carried out using the indirect immunofluoresence antibody (IFA) test. The IFA test may be confounded by cross-reactivities between a number of the canine ehrlichial pathogens. This article presents a review of the ehrlichial diseases affecting dogs with reference to their immune responses, host specificities, cross-reactivites and diagnosis. Diagnostic means such as Western immunblot, dot-blot and PCR are discussed. The use of the IFA test as a diagnostic means for E. canis is presented along with its potential pitfalls. The review emphasizes that the disease process, cross-reactivites with other ehrlichial species, multiple tick-borne infections and persistent IFA antibody titers post-treatment, should all be considered when interpreting E. canis serological results.

Animals↗
PubMed2001

Study of Theileria annulata population structure during bovine infection and following transmission to ticks.

Tams1 is the polymorphic immunodominant merozoite-piroplasm surface protein of Theileria annulata. Evidence for selection of divergent forms of Tams1 has been obtained recently. This study was performed to address whether selection takes place during persistent infection of the bovine host or during passage through the Hyalomma tick vector. Four calves were infected with a T. annulata isolate representing multiple parasite genotypes. The development of the parasite population was analysed by denaturing gradient gel electrophoresis (DGGE) using the Tams1 gene as a marker. In addition, the parasitaemia was measured by a semi-quantitative reverse line blot hybridization assay in order to correlate Tams1 variation to changes in parasitaemia. It was found that both parasitaemia and parasite population displayed limited variation during persistent infection. Ticks were allowed to acquire T. annulata during 2 periods of the bovine infection. Tams1 alleles detected in ticks fed during acute infection were identical to the population in the bovine host. However, ticks fed during the carrier status acquired parasites showing a single Tams1 isotype that represented, in several cases, a minor population in the bovine host at the time of infestation. Although only a limited number of ticks were studied, these preliminary data suggest that specific parasite genotypes may be selected during tick transmission from a carrier animal.

Animals↗
PubMed2001

Evidence for the utility of the Bm86 antigen from Boophilus microplus in vaccination against other tick species.

The Bm86 antigen, as originally identified in Boophilus microplus, is the basis of commercial tick vaccines against this tick species. The potential for using this antigen or homologues of the antigen in vaccination against other tick species has been assessed. We have conducted vaccine trials in cattle using the B. microplus-derived recombinant Bm86 vaccine (TickGARD) using pairs of vaccinated calves and control calves. These were infested with B. microplus and Boophilus decoloratus larvae simultaneously. For both species, the numbers of engorged female adult ticks, their weight and egg-laying capacity were all reduced, leading to a reduction in reproductive capacity of 74% for B. microplus and 70% for B. decoloratus. Hyalomma anatolicum anatolicum ticks were fed both as immatures as well as adults on vaccinated calves and non-vaccinated controls. There was an overall 50% reduction in the total weight of nymphs engorging on vaccinated calves, and a suggestion of a subsequent effect on feeding adults. For Hyalomma dromedarii there was a 95% reduction in the number of nymphs engorging and a further 55% reduction in weight of those ticks surviving. Rhipicephalus appendiculatus and Amblyomma variegatum ticks were fed simultaneously both as immatures and subsequently as adults. There was no evidence for a significant vaccination effect. Finally, the amino acid sequence of a Bm86 homologue found in H. a. anatolicum unequivocally demonstrated the conservation of this molecule in this species. Our strategy for the development of multivalent anti-tick vaccines is discussed in relation to these findings.

Amino Acid Sequence↗
PubMed2001

Antibody responses to MAP 1B and other Cowdria ruminantium antigens are down regulated in cattle challenged with tick-transmitted heartwater.

Serological diagnosis of heartwater or Cowdria ruminantium infection has been hampered by severe cross-reactions with antibody responses to related ehrlichial agents. A MAP 1B indirect enzyme-linked immunosorbent assay that has an improved specificity and sensitivity for detection of immunoglobulin G (IgG) antibodies has been developed to overcome this constraint (A. H. M. van Vliet, B. A. M. Van der Zeijst, E. Camus, S. M. Mahan, D. Martinez, and F. Jongejan, J. Clin. Microbiol. 33:2405-2410, 1995). When sera were tested from cattle in areas of endemic heartwater infection in Zimbabwe, only 33% of the samples tested positive in this assay despite a high infection pressure (S. M. Mahan, S. M. Samu, T. F. Peter, and F. Jongejan, Ann. N.Y. Acad. Sci 849:85-87, 1998). To determine underlying causes for this observation, the kinetics of MAP 1B-specific IgG antibodies in cattle after tick-transmitted C. ruminantium infection and following recovery were investigated. Sera collected weekly over a period of 52 weeks from 37 cattle, which were naturally or experimentally infected with C. ruminantium via Amblyomma hebraeum ticks, were analyzed. MAP 1B-specific IgG antibody responses developed with similar kinetics in both field- and laboratory-infected cattle. IgG levels peaked at 4 to 9 weeks after tick infestation and declined to baseline levels between 14 and 33 weeks, despite repeated exposure to infected ticks and the establishment of a carrier state as demonstrated by PCR and xenodiagnosis. Some of the serum samples from laboratory, and field-infected cattle were also analyzed by immunoblotting and an indirect fluorescent-antibody test (IFAT) to determine whether this observed seroreversion was specific to the MAP 1B antigen. Reciprocal IFAT and immunoblot MAP 1-specific antibody titres peaked at 5 to 9 weeks after tick infestation but also declined between 30 and 45 weeks. This suggests that MAP 1B-specific IgG antibody responses and antibody responses to other C. ruminantium antigens are down regulated in cattle despite repeated exposure to C. ruminantium via ticks. Significantly, serological responses to the MAP 1B antigen may not be a reliable indicator of C. ruminantium exposure in cattle in areas of endemic heartwater infection.

Animals↗
PubMed2001

Heartwater (Cowdria ruminantium infection) as a cause of postrestocking mortality of goats in Mozambique.

A serological survey in Mozambique to detect antibodies to Cowdria ruminantium, the etiologic agent of heartwater, revealed a seroprevalence of 8.1% (n = 332) for goats in the northern province of Tete and of 65.6% (n = 326) for goats in the southern provinces. Translocation of 10 serologically negative goats from Tete to farms in the south resulted in two clinical cases of heartwater that were fatal. In addition, four goats seroconverted within the study period of 5 weeks. One goat showed no symptoms. Two goats died of other causes, whereas the remaining goat went missing after 1 week. Experimental needle infections of goats and sheep were conducted to confirm results and to isolate different strains of C. ruminantium. These data indicate that translocation of goats from the north to the south of Mozambique bears a high risk of C. ruminantium infection, which can cause fatal disease.

Animals↗
PubMed2000

[Tick-borne fever (Ehrlichia phagocytophila infection) on a dairy farm in Friesland].

Disease outbreaks, associated with ixodid ticks, among cows on a dairy farm in Friesland, in the north of the Netherlands, were monitored during the summers of 1996, 1997, and 1998. The most important symptoms were a sudden drop in milk yield, fever, apathy, and problems with locomotion. The diagnosis 'tick-borne fever' was confirmed by finding Ehrlichia phagocytophila inclusion bodies in neutrophils of blood smears from sick animals. Significant economic losses due to the disease were recorded each year. Borrelia burgdorferi, although transmitted by the same tick, did not seem to be involved. Further research on tick-borne fever is of particular relevance in connection with recent E. phagocytophila cases diagnosed in dogs and in a human patient in the Netherlands.

Animals↗
PubMed2000

Molecular characterisation of the Theileria buffeli/orientalis group.

Benign bovine Theileria parasites known as either Theileria buffeli, Theileria orientalis or Theileria sergenti are classified on basis of their morphology, vector specificity, pathogenicity and 18S small subunit ribosomal RNA or major piroplasm protein (MPSP) sequences. Since most isolates have been characterized on only some of these criteria and the existing confusion in nomenclature, an analysis was performed on eight different isolates to combine 18S rRNA data with MPSP data and the results were compared with available biological parameters. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach for both genes was used in combination with reverse line blot hybridisation for the 18S rRNA gene. Both MPSP and 18S rRNA genes were cloned and sequenced from parasites displaying aberrant MPSP RFLP profiles. Phylogeny based on published and determined 18S rRNA and MPSP sequences did correlate within the same isolate but there was no obvious correlation between molecular and biological data. Based on these findings, we suggest that the appropriate name for all these parasites is Theileria buffeli. A more specific nomenclature should be assigned when new molecular markers may become available.

Animals↗
PubMed2000

Generation of a mosaic pattern of diversity in the major merozoite-piroplasm surface antigen of Theileria annulata.

The polypeptide Tams1 is an immunodominant major merozoite piroplasm surface antigen of the protozoan parasite Theileria annulata. Generation and selection of divergent antigenic types has implications for the inclusion of the Tams1 antigen in a subunit recombinant vaccine or use in the development of a diagnostic ELISA. In this study a total of 129 Tams1 sequences from parasites isolated in Bahrain, India, Italy, Mauritania, Portugal, Spain, Sudan, Tunisia and Turkey were obtained to estimate the extent of Tams1 diversity throughout a wide geographical range. Significant sequence diversity was found both within and between isolates and many of the sequences were unique. No geographical specificity of sequence types was observed and almost identical sequences occurred in different geographical areas and a panmictic population structure is suggested by our results. A sliding window analysis identified sub-regions of the molecule where selection for amino acid changes may operate. Evidence is also presented for the generation of diversity through intragenic recombination with switching of corresponding variable domains between alleles. Recombination to exchange variable domains appears to occur throughout the length of the gene sequence, and has the potential to generate a mosaic pattern of diversity.

Amino Acid Sequence↗
PubMed2000

Cowdria ruminantium antibodies in acaricide-treated and untreated cattle exposed to Amblyomma variegatum ticks in The Gambia.

An indirect enzyme-linked immunosorbent assay (ELISA), based on the major antigenic protein I fragment B (MAPI-B) of Cowdria ruminantium, was used to assess seroprevalence in cattle in The Gambia. Two groups of 20 N'Dama and 20 Gobra zebu cattle were monitored for 12 months with flumethrin treatment and for another 10 months without acaricidal treatment. Two groups of 20 N'Dama and 20 Gobra cattle served as untreated controls. During the period of acaricidal treatment, the cumulative proportions of positive serum samples were 25.6 +/- 5.6% (+/- confidence interval) and 34.7 +/- 6.8% in treated N'Dama and Gobra cattle respectively; the proportion of positive sera in untreated cattle was 52.2 +/- 6.9% in N'Damas and 61.4 +/- 7.3% in Gobras. Within breed, difference in antibody prevalence between treated and untreated cattle was significant (P < 0.001) but between breed differences were not significant. In the 10 months following suspension of acaricide application, there was an increase of proportion of positive serum samples in previously treated N'Dama and Gobra cattle. In both previously treated and untreated animals the peak of positive seroreactions occurred during and subsequent to the period of activity of Amblyomma variegatum adults. Cumulative seroprevalences in previously treated N'Dama and Gobra cattle were 32.6 +/- 6.9% and 44.7 +/- 8.5%, respectively; in untreated animals seroprevalence was 38.6 +/- 7.2% in N'Dama and 65.3 +/- 8.4% in Gobra cattle. Throughout the study period, within the N'Dama breed, the seropositive rate in previously treated cattle did not differ from that in untreated animals. Conversely, within the Gobra breed, the number of positive seroreactions was higher (P < 0.002) in untreated animals than in previously treated cattle. These results provide a support for designing A. variegatum and heartwater control strategies, if necessary, in The Gambia in relation to cattle breeds.

Anaplasmataceae↗
PubMed2000

Characterization of attenuated Theileria annulata vaccines from Spain and the Sudan.

Theileriosis caused by Theileria annulata can be effectively prevented by vaccination with attenuated, cultured schizonts. Although these attenuated vaccines have been applied for a long time, not much is known about the fate of the vaccine strain in the field. Here, two experimental Spanish vaccine strains originating in Cádiz and Cáceres, and one Sudanese strain are studied to address the development of a carrier status and the infectivity for Hyalomma ticks. Moreover, the heterogeneity of the merozoite surface protein, Tams1, was analyzed in search for an attenuation marker. Using the sensitive reverse line blot (RLB) hybridization, the development of a low level carrier status was demonstrated in the Cáceres and Sudanese line vaccinated calves. Although no signal was detected in the Cádiz line vaccinated calves, seroconversion against the schizont stage was observed, as it was in all other calves. The experimental transmission of T. annulata by Hyalomma ticks to naïve calves was unsuccessful for all cell line inoculated calves. Tams1 heterogeneity indicated a clonal selection of parasites during the process of attenuation, but the Tams1 sequence itself has no connection with the attenuation status. In conclusion, a carrier status develops in attenuated schizont culture vaccinated calves, but is not infective for Hyalomma ticks. Based on these data, the risk for spread of the vaccine strains in the field may be very low.

Amino Acid Sequence↗
PubMed2000

Integrated molecular diagnosis of Theileria and Babesia species of cattle in Italy.

A reverse line blot hybridization (RLB) test was developed to specifically identify six Theileria spp. (T. annulata, T. parva, T. mutans, T. velifera, T. taurotragi, and T. buffeli/orientalis) and three Babesia spp. (B. bovis, B. bigemina, and B. divergens). No cross reaction was observed with other livestock pathogens (such as Anaplasma marginale, A. centrale, A. ovis, Cowdria ruminantium, Trypanosoma brucei, T. congolense, and T. vivax). This method was used to test bovine blood samples collected in Sicily in April and November, 1998. Preliminary results indicated that T. annulata and T. buffeli/orientalis were the main species observed in cattle blood. Babesia species represented 1.8% and 23.5% in April and November, respectively.

Animals↗
PubMed2000

Development of an indirect Tams1 enzyme-linked immunosorbent assay for diagnosis of Theileria annulata infection in cattle.

An enzyme-linked immunosorbent assay (ELISA) was developed based on a recombinant major Theileria annulata merozoite surface antigen, Tams1. Four different recombinant proteins derived from two different Tams1 alleles, both in two different truncated forms, were tested for their performance in the ELISA. Furthermore, antigen concentration, various buffers, washing protocol, and the choice of anti-total-immunoglobulin G (IgG), anti-IgG1, or anti-IgG2 as second antibody were evaluated. The performance of the resulting ELISA was analyzed by measuring the coefficient of variation (CV). A total of 22 sera were analyzed over the measurement range, resulting in a CV of ca. 10%, whereas 30% variation is the maximum acceptable. The cutoff value was determined by the two-graph receiver operating characteristic (TG-ROC), using the indirect fluorescent antibody test (IFAT) as a reference. It was shown that up to 3 months postinfection (p.i.) IFAT is more sensitive and specific, whereas beyond 3 months p.i. ELISA performed as well as IFAT. The cutoff was determined at maximal sensitivity, based on the TG-ROC after 3 months p.i. Nine calves experimentally infected with four different T. annulata stocks remained positive in the ELISA for at least 1 year p.i. Finally, limited cross-reaction was found only with T. parva antisera, but not with any other Theileria or Babesia species. Since the T. parva endemic area hardly overlaps with T. annulata, the Tams1 ELISA has the potential to become a useful tool in the epidemiology of tropical theileriosis.

Animals↗