Parasitic coinfections among selected smallholder goat flocks in Malaysia

@#This paper describes the occurrence of multiple parasitic infection with special reference to emerging haemotropic Mycoplasma ovis. A cross-sectional survey of four selected goat flocks was conducted to collect samples and management information. Blood samples were processed using microhaematocrit centrifugation to determine the packed cell volume (PCV). Detection and morphological identification of blood protozoa and haemotropic Mycoplasma ovis from Giemsa-stained smears were done microscopically. M. ovis infection was classified mild (1-29% infected cells), moderate (30-59% infected cells), or severe (above 60% infected cells). Faecal floatation and McMaster faecal egg count were used to detect and classify strongyle infections as negative (no eggs/oocysts), light (< 500 epg), Moderate (500 – 1000 epg), or severe (>1000 epg) and coccidia infection as light (<1800 opg), moderate (1800 – 6000 opg), or severe (>6000 opg). There were 149 goats with blood protozoa (57.98%; 95% CI: 51.87 – 63.85) and 204 goats with GI parasites (79.38%; 95% CI: 74.02 - 83.87) involved in single (15.8%; 95% CI: 11.7 – 21.0) or multiple (84.2%; 95% CI: 79.0 – 88.3) infections. The risk of Strongyles increases by 2.49 (95% CI: 1.24 – 4.99) in females versus males and 6.79 (95% CI: 3.25 – 14.18, p =0.000) in adults versus young. The risk of Eimeria species increases by 7.32 (95% CI: 3.45 – 15.50, p =0.000) in adults versus young, while M. ovis coinfection risk increases by 4.51 (95% CI: 1.40 – 14.50, p =0.000) in female versus males. Thin animals had a significantly higher (p<0.05) mean burden of Strongyle (1370.37 ± 345.49) and Eimeria (1594.12 ± 695.26) than the moderate and fat goats. The PCV was negatively associated with mean faecal egg count (FEC) (p<0.05) such that a lower PCV was recorded in animals with a higher Strongyle epg output. A severe burden of M. ovis was accompanied by an increased nematode FEC and decreased haematocrit (p<0.05). Coinfections of Strongyles, or Eimeria species involving M. ovis were associated with a higher parasitaemia compared with single infections (p<0.05). This study highlights the importance of M. ovis and Strongyle or Eimeria species coinfections among goat flocks and provides valuable data for developing and implementing an integrated herd health management program for parasite control among low-input smallholder flocks.

Toxoplasma gondii SAG2, SAG3 and GRA6 alleles and single nucleotide polymorphism in congenital infections with known parasite load and clinical outcome

ABSTRACT Amniotic fluid DNA samples were genotyped by multilocus-nested-PCR-RFLP, but only three of 11 markers amplified 113 of 122 (92.6%) samples, resulting in 12 untyped and 101 partial non-archetypal genotypes. The 101 typed samples were subdivided into four groups: G1 with 73 samples (5'and 3' SAG2 allele I + SAG3 allele III + GRA6 allele III), 53 had parasite load ≤ 102 parasites/mL (43 asymptomatic, 10 mild infections), 17 had load > 102 and ≤ 103 (one mild, 13 moderate and three severe), and three had load > 103 parasites/mL (three severe); G2 with 22 samples (5'and 3' SAG2 allele I + SAG3 allele III), all parasite load levels ≤ 102 parasites/mL (18 asymptomatic and four mild); G3 with five samples (5' and 3' SAG2 allele I + SAG3 allele II), parasite load ≤ 102 parasites/mL (three asymptomatic and two mild); G4 with one sample (5' and 3' SAG2 allele II + SAG3 allele II + GRA6 allele I), a parasite load < 102 parasites/mL in an asymptomatic infant. After DNA sequencing, restriction sites confirmed SAG2, SAG3 and GRA6 alleles in 98.7%, 100% and 100% of the cases, respectively, while single nucleotide polymorphisms confirmed 90% of 5'-SAG2 allele I; 98.7% of 3'-SAG2 allele I; 98% of SAG-3 allele III, but only 40% of GRA6 allele III results. For the moment, partial non-archetypal genotypes of parasites did not show any relationship with either parasite load in amniotic fluid samples or clinical outcome of infants at the age of 12 months.

Performance of POC-CCA® in diagnosis of schistosomiasis mansoni in individuals with low parasite burden

Abstract: INTRODUCTION: Schistosomiasis, caused by Schistosoma mansoni, is a public health concern in Brazil. However, the most popular diagnostic method, the Kato-Katz technique, exhibits low sensitivity in low-endemicity areas. We aimed to compare the performance of an immunological assay, the point-of-care circulating cathodic antigen (POC-CCA®) test, with that of two parasitological techniques in a low-endemicity population. METHODS: Our study included 141 individuals living in Estreito de Miralta, Minas Gerais, Brazil. Fecal samples were obtained from all participants and analyzed for schistosomiasis using two parasitological techniques: the Kato-Katz technique and the saline gradient technique. Additionally, POC-CCA® strips were utilized for testing urine samples. The results obtained by the different techniques were compared. RESULTS: Analysis of two or 24 slides using the Kato-Katz technique resulted in a positivity rate of 10.6% (15/141) or 19.1% (27/141), respectively. The saline gradient technique yielded a positivity rate of 17.0% (24/141). The prevalence according to both parasitological techniques was 24.1% (34/141). The POC-CCA® test yielded a positivity rate of 22.7% (32/141); however, the positivity rate was merely 2.1% if trace results were considered negative. The agreements observed between POC-CCA® and the parasitological techniques were good (Kappa indexes > 0.64). The POC-CCA® test was more sensitive than the two-slide Kato-Katz technique (p < 0.05) in detecting cases of S. mansoni infection when trace results were considered positive. CONCLUSIONS: These findings reinforce the importance of using multiple diagnostic techniques in low-endemicity areas for effective control of disease.

Tissue tropism and parasite burden of Toxoplasma gondii RH strain in experimentally infected mice

OBJECTIVE@#To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.@*METHODS@#In this survey 16 Balb/c mice were inoculated with 1 × 10(4) alive tachyzoites of Toxoplasma gondii RH strain. After 1, 2, 3 days post infection and the last day (before death), different tissues of mice including blood, brain, eye, liver, spleen, kidney, heart and muscle were harvested. Following tissues DNA extraction, the parasite burden was quantified using real time QPCR targeting the B1 gene (451 bp).@*RESULTS@#It showed that Toxoplasma after intraperitoneal injection was able to movement to various tissues in 24 hours. Parasite burden was high in all tissues but the most number of parasites were observed in kidney, heart and liver, respectively.@*CONCLUSIONS@#These data provide significant baseline information about Toxoplasma pathogenesis, vaccine monitoring and drug efficiency.

Schistosoma mansoni in a low-prevalence area in Brazil: the importance of additional methods for the diagnosis of hard-to-detect individual carriers by low-cost immunological assays

Schistosomiasis diagnosis is based on the detection of eggs in the faeces, which is laborious and lacks sensitivity, especially for patients with a low parasite burden. Immunological assays for specific antibody detection are available, but they usually demonstrate low sensitivity and/or specificity. In this study, two simple immunological assays were evaluated for the detection of soluble Schistosoma mansoni adult worm preparation (SWAP) and egg-specific IgGs. These studies have not yet been evaluated for patients with low parasite burdens. Residents of an endemic area in Brazil donated sera and faecal samples for our study. The patients were initially diagnosed by a rigorous Kato-Katz analysis of 18 thick smears from four different stool samples. The ELISA-SWAP was successful for human diagnosis with 90% sensitivity and specificity, confirming the Kato-Katz diagnosis with nearly perfect agreement, as seen by the Kappa index (0.85). Although the ELISA-soluble S. mansoni egg antigen was 85% sensitive, it exhibited low specificity (80%; Kappa index: 0.75) and was more susceptible to cross-reactivity. We believe that immunological assays should be used in conjunction with Kato-Katz analysis as a supplementary tool for the diagnosis of schistosomiasis for patients with low infection burdens, which are usually hard to detect.

Experimental infection with Leishmania chagasi in immunosuppressed Balb/c mice: cytokines and parasite burdens

The immune response in leishmaniasis may result in a polarization of the T lymphocyte subpopulation, altering cell phenotype and resulting in immune protection or disease exacerbation. Leishmania may persist in the body either during asymptomatic infections or after treatment, which represents high risk under immunosuppression. The objective of this study was to evaluate the effect of infection with immunosuppression by dexamethasone associated with pentoxifylline on animal weight, spleen weight, spleen and hepatic parasitic load and immunopathology, as well as the IFN-ã and IL-10 production in spleen cell culture of Balb/c mice infected with Leishmania chagasi. The infection did not cause body weight gain in animals, but both the weight and size of the spleen were increased. The immunosuppression using dexamethasone associated with pentoxifylline affected body weight gain and spleen weight and size in both infected and non-infected animals. The immunosuppression did not significantly alter the course of the splenic or hepatic parasite burden. Dexamethasone and pentoxifylline significantly affected cytokine production, but did not influence the Th1/Th2 ratio in infected animals.(AU)

The effect of antioxidant properties of aqueous garlic extract and Nigella sativa as anti-schistosomiasis agents in mice / O efeito das propriedades antioxidantes do extrato aquoso do alho e da Nigella sativa como agentes anti-esquistossômicos no camundongo

The aim of this study was to assess the antioxidant and anti-schistosomal activities of the garlic extract (AGE) and Nigella sativa oil (NSO) on normal and Schistosoma mansoni-infected mice. AGE (125 mg kg-1, i.p.) and NSO (0.2 mg kg-1, i.p.) were administrated separately or in combination for successive 28 days, starting from the 1st day post infection (pi). All mice were sacrificed at weeks 7 pi. Hematological and biochemical parameters including liver and kidney functions were measured to assess the progress of anemia, and the possibility of the tissue damage. Serum total protein level, albumin, globulin and cholesterol were also determined. Malondialdehyde (MDA) and glutathione (GSH) levels were determined in the liver tissues as biomarkers for oxidative and reducing status, respectively. The possible effect of the treatment regimens on Schistosoma worms was evaluated by recording percentage of the recovered worms, tissue egg and oogram pattern. Result showed that, protection with AGE and NSO prevented most of the hematological and biochemical changes and markedly improved the antioxidant capacity of schistosomiasis mice compared to the infected-untreated ones. In addition, remarkable reduction in worms, tissue eggs and alteration in oogram pattern were recorded in all the treated groups. The antioxidant and antischistosomal action of AGE and NSO was greatly diverse according to treatment regimens. These data point to these compounds as promising agents to complement schistosomiasis specific treatment.

O propósito deste estudo foi verificar os efeitos anti-oxidantes e anti-esquistossômicos do extrato de alho (AGE) e do óleo da Nigella sativa (NSO) em camundongos normais e infectados com S. mansoni. AGE (125 mg/kg, i.p. ) e NSO (0,2 mg/kg, i.p.) foram administrados separadamente ou em combinação por 28 dias sucessivos começando do primeiro dia pós infecção (p.i.). Todos os camundongos foram sacrificados sete semanas p.i. Parâmetros hematológicos e bioquímicos incluindo funções renais e hepáticas foram medidos para avaliar o progresso da anemia e a possibilidade de dano tecidual. O nível total de proteínas séricas, albumina, globulina e colesterol foram também medidos. Níveis de malondialdeído (MDA) e glutationa (GSH) foram determinados em tecido hepático como biomarcações para o estado oxidativo e redutor, respectivamente. O possível efeito dos tratamentos sobre os vermes de Schistosoma foram avaliados através do percentual de vermes recuperados, ovos no tecido e o oograma. Resultados mostraram que a proteção com AGE e NSO preveniu a maior parte das alterações hematológicas e bioquímicas e melhoraram bastante a capacidade anti-oxidante de camundongos com esquistossomose comparados com aqueles infectados e não tratados. Adicionalmente, foi registrado uma acentuada redução nos vermes, ovos no tecido e alterações do oograma. A ação anti-oxidante e anti-esquistossômica do AGE e NSO foi diferente de acordo com os vários tratamentos. Estes dados mostram que estes compostos são agentes promissores para complementar o tratamento específico da esquistossomose.