Identifikacija podtipova protozoona Trypanosoma vivax izdvojenih iz goveda i koza pomoću mikrosatelitskih markera.

Microsatellite DNA polymorphisms can be utilised to assess intra-specific genetic diversity and hence are useful for characterisation of species and strains of trypanosomes. Here, we present four new microsatellite markers specific for T. vivax isolated from Ugandan cattle and goats. The GeneDB partial shotgun 5x coverage sequence of T. vivax available as of 1st August 2005 was used and targeted the genomic sequence of T. vivax that has no cross amplification with other livestock-infective trypanosomes. Only di-; tri-; tetra;- and pentanucleotide microsatellites not less than five units were selected. Although pentanucleotide repeats on screening appeared to have the desired variability, they gave poorer PCR products compared to di-, tri- and tetranucleotide repeats. Mononucleotide repeats presented difficulty in detecting visible bands on agarose gels from their amplification and were omitted from this study. Clear length polymorphism was obtained with guanine, thymine and adenine repeated 16 times (GTA)16 while cytosine, adenine, cytosine and thymine (CACT)15 gave size and length variability. Bands of similar size were obtained from thymine and adenine (TTA)24 microsatellite, approximately 150 base pairs long and 180-200 base pairs from the cytosine and adenine (CA)26 microsatellite. These findings suggest that different subtypes of T. vivax exist in Uganda; the polymorphic forms derived from microsatellite band size differences may suggest this parasite exhibits virulence differences as has been shown in T. Congolense subtypes.Polimorfizam mikrosatelitske DNA može se rabiti za procjenu unutarvrsne genetske raznolikosti pa tako i za karakterizaciju vrsta i sojeva tripanosoma. Prikazana su četiri nova mikrosatelitska markera specifična za vrstu T. vivax izdvojenu iz goveda i koza u Ugandi. GenDB kratka i specifična sekvencija T. vivax dostupna nakon 1. kolovoza 2005. bila je ciljano rabljena za određivanje genomskoga slijeda za protozoon T. vivax koji nije pokazivao križne reakcije s drugim tripanosomama zaraznima za stoku. Izabrani su bili samo di-, tri-, tetrai pentanukleotidni mikrosateliti. Premda se činilo da pentanukleotidne ponavljajuće sekvencije u probirnom testu imaju potrebnu varijabilnost, one su dale lošije PCR proizvode u odnosu na di-, tri- i tetranukleotidne ponavljajuće sekvencije. Mononukleotidne ponavljajuće sekvencije nisu dale jasno vidljive trake na agaroznom gelu pa nisu bile dalje istražene. Jasan polimorfizam postignut je upotrebom gvanina, timina i adenina sa šesnaesterostrukim ponavljanjem (GTA)16 dok je sekvencija citozin, adenin, citozin i timin (CACT)15 bila varijabilna u odnosu na veličinu i dužinu. Sekvencije slične veličine bile su dobivene od mikrosatelita koji su sadržavali timin i adenin (TTA)24, a one od 150 parova baza te 180 - 200 parova baza od mikrosatelita citozina i adenina (CA)26. Ovi nalazi govore u prilog postojanju različitih podtipova protozoona T. vivax u Ugandi, koji bi se mogli odlikovati i različitom virulencijom kao što je dokazano za podtipove T. congolense

Effect of praziquantel treatment of Schistosoma mansoni during pregnancy on intensity of infection and antibody responses to schistosome antigens: results of a randomised, placebo-controlled trial

BACKGROUND: Praziquantel treatment of schistosomiasis during pregnancy was only recommended in 2002; hence the effects of treatment during pregnancy are not fully known. We have therefore evaluated the effects on infection intensity and the immunological effects of praziquantel treatment against Schistosoma mansoni during pregnancy, compared with treatment after delivery. METHODS: A nested cohort of 387 Schistosoma mansoni infected women was recruited within a larger trial of de-worming during pregnancy. Women were randomised to receive praziquantel or placebo during pregnancy. All women were treated after delivery. Infection intensity after treatment was assessed by a single Kato-Katz examination of stool samples with duplicate slides and categorised as undetected, light (1-99 eggs per gram (epg)), moderate (100-399 epg) or heavy (>or=400 epg). Antibodies against S. mansoni worm and egg antigens were measured by ELISA. Results were compared between women first treated during pregnancy and women first treated after delivery. RESULTS: At enrollment, 252 (65.1%) of the women had light infection (median (IQR) epg: 35 (11, 59)), 75 (19.3%) moderate (median (IQR) epg: 179(131, 227)) and 60 (15.5%) had heavy infection (median (IQR) epg: 749 (521, 1169)) with S. mansoni. At six weeks after praziquantel treatment during pregnancy S. mansoni infection was not detectable in 81.9% of the women and prevalence and intensity had decreased to 11.8% light, 4.7% moderate and 1.6% heavy a similar reduction when compared with those first treated after delivery (undetected (88.5%), light (10.6%), moderate (0.9%) and heavy (0%), p = 0.16). Parasite specific antibody levels were lower during pregnancy than after delivery. Praziquantel treatment during pregnancy boosted anti-worm IgG isotypes and to a lesser extent IgE, but these boosts were less pronounced than in women whose treatment was delayed until after delivery. Praziquantel had limited effects on antibodies against egg antigens. CONCLUSION: S mansoni antigen-specific antibody levels and praziquantel-induced boosts in antibody levels were broadly suppressed during pregnancy, but this was not associated with major reduction in the efficacy of praziquantel. Long-term implications of these findings in relation to resistance to re-infection remain to be explored

Polyandry Is a Common Event in Wild Populations of the Tsetse Fly Glossina fuscipes fuscipes and May Impact Population Reduction Measures

Glossina fuscipes fuscipes is the most common tsetse species in Uganda where it is responsible for transmitting Trypanosoma brucei rhodensiense and Trypanosoma brucei gambiense parasites causing sleeping sickness in humans in addition to related trypanosomes that cause Nagana in cattle. An understanding of the reproductive biology of this vector is essential for the application of sustainable control/eradication methods such as Sterile Insect Technique (SIT). We have analysed the number of times a female mates in the wild as this aspect of the reproductive behaviour may affect the stability and size of populations. We provide evidence that remating is a common event in the wild and females store sperm from multiple males, which may potentially be used for insemination. In vector eradication programmes, re-infestation of cleared areas and/or in cases of residual populations, the occurrence of remating may unfortunately enhance the reproductive potential of the re-invading propagules. We suggest that population age structure may influence remating frequency. Considering the seasonal demographic changes that this fly undergoes during the dry and wet seasons, control programmes based on SIT should release large numbers of sterile males, even in residual surviving target populations, in the dry season

Serum biochemical parameters and cytokine profiles associated with natural African trypanosome infections in cattle.

BACKGROUND: Animal African trypanosomiasis (AAT) greatly affects livestock production in sub-Saharan Africa. In Ghana prevalence of AAT is estimated to range between 5 and 50%. Studies have reported serum biochemical aberrations and variability in cytokine profiles in animals during infection. However, information regarding the biochemical parameters and cytokine profiles associated with natural infections are limited. This study was therefore aimed at investigating changes in the levels of serum biochemical parameters and inflammatory cytokines during a natural infection. METHODS: Nested internal transcribed spacer (ITS)-based PCR and sequencing were used to characterise trypanosome infection in cattle at two areas in Ghana (Adidome and Accra) of different endemicities. The cattle were sampled at four to five-week intervals over a period of six months. Levels of serum biochemical parameters, including creatinine, cholesterol, alkaline phosphatase (ALP), alanine aminotransferase (ALT), total bilirubin and total protein and cytokines (interleukin 10, interleukin 4, interleukin 12, interferon gamma and tumor necrosis factor alpha) were measured in serum samples and then compared between infected cattle and uninfected controls. RESULTS: The predominant trypanosome species detected in Accra (non-endemic) and Adidome (endemic) were Trypanosoma theileri and Trypanosoma vivax, respectively. Serum biochemical parameters were similar between infected and uninfected cattle in Accra. Infected cattle at Adidome however, had significantly higher levels of ALP, creatinine, total protein and total bilirubin (P < 0.05) and significantly lower levels of cholesterol (P < 0.05) at specific time points. At basal levels and during infection, significantly higher pro-inflammatory to anti-inflammatory (Th1/Th2) cytokine ratios were observed in cattle at Adidome compared to Accra (P < 0.05), indicating a shift towards Th1 immune response in Adidome. Levels of IL-10 were, however, significantly elevated in infected cattle in Accra (P < 0.05), suggesting high anti-inflammatory cytokine response in Accra. CONCLUSION: These results suggests that cattle in an endemic area repeatedly infected with trypanosomes of different species or different antigenic types demonstrate high pro-inflammatory (Th1) immune response and biochemical alterations whereas cattle in a non-endemic area with predominantly chronic T. theileri infections demonstrate high anti-inflammatory response and no biochemical alterations

Influence de l’infection à <em>Trypanosoma congolense</em> sur quelques constituants protéiques et inorganiques du sang chez le mouton

Cette étude avait pour objet d'évaluer les variations des concentrations plasmatiques de zinc, cuivre, calcium, magnésium, phosphate inorganique, protéines totales, albumine et globuline, de la sidérémie, ainsi que la capacité de fixation du fer chez des moutons infectés par Trypanosoma congolense. Les résultats ont montré que l'infection n'avait pas d'effet significatif sur les concentrations plasmatiques de zinc, cuivre, calcium, magnésium et phosphate inorganique. Les sidérémies des animaux infectés étaient plus élevées que celles des animaux témoins, mais pas de manière significative. Les animaux infectés développèrent de l'hypoalbuminémie et de l'hyperglobulinémie, alors que les variations en protéines totales n'étaient pas significatives. La pertinence de ces variations quant au mécanisme pathogénique de l'infection à Trypanosoma congolense est discutée