Mean Number Of Parasites Research Articles

Parasite infection in a cell population: role of the partitioning kernel.

We consider a cell population subject to a parasite infection. Cells divide at a constant rate and, at division, share the parasites they contain between their two daughter cells. The sharing may be asymmetric, and its law may depend on the number of parasites in the mother. Cells die at a rate which may depend on the number of parasites they carry, and are also killed when this number explodes. We study the survival of the cell population as well as the mean number of parasites in the cells, and focus on the role of the parasites partitioning kernel at division.

Effectiveness of dihydroartemisinin-piperaquine after 10 years as treatment for vivax malaria in Indonesia.

Dihydroartemisin-piperaquine (DHP) is a type of artemisinin-based combination therapy (ACT) that is extensively used in Indonesia as first-line malaria treatment over the past 10 years. Therefore, DHP has been known to have high efficacy, but re-evaluation of the efficacy was needed since the treatment was being used for a long time. A cohort prospective study on pediatric and adult patients diagnosed with vivax malaria in Kualuh Leidong health centre was conducted from November 2019 - April 2020 to evaluate the efficacy of DHP for the treatment of malaria vivax. The efficacy of DHP was monitored by evaluating the clinical symptoms and serial peripheral blood smear at day 1,2,3,7,14,21 and 28. A total of 60 children and adults diagnosed with malaria vivax were enrolled for this study. Major symptoms such as fever, sweating and dizziness were found in all of subjects. The mean number of parasites on day 0 of observation in the child and adult groups was 313.33/µL and 328/µL respectively (p = 0.839). Meanwhile, the mean number of gametocytes on day 0 was 74109.33/µL in the child group and 61661.33/µL in the adult group. There was a reduction in the number of gametocytes on the 1st day of observation in the child and adult groups to 669.33/µL and 489.33/µL respectively (p = 0.512). No recrudescence occurred in either group within 28 days of observation. DHP is still efficacious and safe as a first-line treatment for vivax malaria in Indonesia, with 100% cure rate at 28 days of observation.

Can orange essential oil reduce the severity of parasitic infection in sheep?

In this study, a three-step experiment was conducted to evaluate the effectiveness of orange essential oil (OEO) to reduce the severity of parasitic infection in lambs naturally infected with gastrointestinal parasites. In the first and second stages of the experiment, the lambs were distributed in groups (n=10): without treatment (control), treated with levamisole (7.5mg/kg), and treated either with 200, 300 or 400mg/kg OEO in the first stage and with two doses of 300 or 350mg/kg each of OEO with a six-hour interval in the second stage. In the third stage of the experiment, 20 lambs were distributed into control and treated groups (two doses of 350mg/kg OEO) and slaughtered for determining the parasite count in the abomasum and small intestine. Evaluations were performed on D0, D3, D7, D10, and D14 by determining the egg count per gram of feces (EPG), and the percentage of EPG reduction was calculated in comparison to D0. Coproculture was performed on days D0 and D14 of the first and second stages of the study. In the first stage, the EPG increased by 20.90 and 100.99% and decreased by 5.54% on D14 in the groups treated with 200, 300, or 400mg/kg OEO, respectively. At the second stage, the EPG of the OEO groups decreased by more than 96% on D3, but on D14 was decreased by 0.82% and 77.07% in the 2×300 and 2×350mg/kg groups, respectively. Haemonchus sp. was the highest percentage of collected larvae in all coproculture tests, ranging from 90 to 100%. In the third stage, there was no difference (P>0.05) in the mean number of parasites between the OEO groups and the control. Although the decrease in EPG of more than 96% on D3 did not persist in the other evaluations, and immature forms and adult parasites were collected at slaughter, the EPG reduction of 77.07% on D14 with the dose of 700mg/kg (OEO2×350) suggests that OEO can help to reduce the severity of parasitic infection and, consequently, to diminish pastures contamination, when used together with other methods to control gastrointestinal parasites in sheep.

Fe3O4@piroctone olamine magnetic nanoparticles: Synthesize and therapeutic potential in cutaneous leishmaniasis

BackgroundIn recent years, magnetic nanoparticles (NMP) as novel materials have been widely used for biomedical, diagnostic and therapeutic purposes like microbial infection therapy. The purpose of this study is to synthesize PO coated iron oxide magnetic nanoparticles (Fe3O4@PO NPs) and their anti-leishmanial effects in vitro and in vivo against cutaneous leishmaniasis. MethodsFe3O4 magnetic nanoparticles were synthesized by the coprecipitation of Fe2 + and Fe3 + ions and used as a nanocarrier for the production of Fe3O4@PO NPs. The in vitro antileishmanial effects of PO-coated Fe3O4 NPs and Fe3O4 NPs (10–200 µg/mL) was determined against the intracellular amastigotes of Leishmania major (MRHO/IR/75/ER) and, then, examined on cutaneous leishmaniasis induced in male BALB/c mice by L. major. The rate of infectivity, production of nitric oxide (NO), and cytotoxic activates of Fe3O4 NPs and Fe3O4@PO NPs on J774-A1 macrophage cells were determined. ResultsThe size scattering of the Fe3O4 NPs and Fe3O4@PO NPs were in the range among 1–40 and 5–55 nm, respectively. The obtained IC50 values were 62.3 ± 2.15 μg/mL, 31.3 ± 2.26 μg/mL, and 52.6 ± 2.15 μg/mL for the Fe3O4 NPs and Fe3O4@PO NPs, and MA, respectively. The results revealed that the mean number of parasites and the mean diameter of the lesions was considerably (p < 0.05) decreased in the infected mice treated with Fe3O4 NPs and Fe3O4@PO NPs. The Fe3O4 NPs and Fe3O4@PO NPs significantly (p < 0.05) prompted the production of NO as a dose-dependent manner. The promastigotes pre-incubated in Fe3O4 NPs and Fe3O4@PO NPs at the concentration of 5 µg/mL had the ability to infect only 41.7% and 28.3% of the macrophages cells. The selectivity index of greater than 10 for Fe3O4 NPs and Fe3O4@PO NPs showed its safety to the J774-A1 macrophage cells and specificity to the parasite. ConclusionThe results of this survey indicated the high potency of Fe3O4@PO NPs to inhibit the growth of amastigote forms of L. major as well as recovery and improvement CL induced by L. major in BALB/c mice without significant cytotoxicity. The results also indicated that, although the possible anti-leishmanial mechanisms of Fe3O4@PO NPs have not been clearly understood, however, the triggering of NO may be considered as one of the possible anti-leishmanial mechanisms of these nanoparticles. However, additional studies, in particular in clinical contexts, are mandatory.

Gastrointestinal parasitic infection in the hazel grouse Tetrastes bonasia in France

The hazel grouse Tetrastes bonasia is a Galliformes species of major conservation interest and threatened throughout Europe. However, little information is currently available on its sanitary status both in the Alps and worldwide. Considering that gastrointestinal parasites are one of the factors negatively impacting on Galliformes population dynamics, the objective of this study is to fill the gaps of knowledge on the parasite-fauna of the Alpine hazel grouse. Twenty-nine hazel grouse were collected in the French Alps during the period 1987–2019 (no samples collected during 1997–1999). All birds were searched for gastrointestinal parasites utilizing conventional parasitological techniques. Prevalence, intensity of infection and abundance (mean number of parasites) were calculated for each parasite species. In addition, parasite richness was evaluated. Forty-one percent (CI95%: 23.4–59.3) of birds harboured parasites, belonging to seven parasite species. Capillaria caudinflata was the most common with a prevalence of 27.6% (CI95%: 11.3–43.8), whereas Eimeria spp. was found with a prevalence of 10.3% (CI95%: 0–21.4). For both parasites, the majority of the infected animals show low parasite load. A low prevalence (3.4% – CI95%: 0–10.1) was detected for Capillaria anatis, Heterakis gallinarum, Raillietina sp., Dispharynx nasuta and Trematodes. To our knowledge, this is the first report of C. anatis and D. nasuta in the hazel grouse, and in general one of the few article providing information on hazel grouse parasite community. Overall, the parasite richness was very low, with 75% of the infected birds carrying one parasite species, 17% two species and only one bird (8%) with three species. This study increases the scarce literature available on the hazel grouse parasites. The epidemiological descriptors reported are particularly useful to compare the parasite-fauna of the hazel grouse across locations and time periods.

Therapeutic Potential of Green Synthesized Copper Nanoparticles Alone or Combined with Meglumine Antimoniate (Glucantime®) in Cutaneous Leishmaniasis.

Background: In recent years, the focus on nanotechnological methods in medicine, especially in the treatment of microbial infections, has increased rapidly. Aim: The present study aims to evaluate in vitro and in vivo antileishmanial effects of copper nanoparticles (CuNPs) green synthesized by Capparis spinosa fruit extract alone and combined with meglumine antimoniate (MA). Methods: CuNPs were green synthesized by C. spinosa methanolic extract. The in vitro antileishmanial activity of CuNPs (10–200 µg/mL) or MA alone (10–200 µg/mL), and various concentrations of MA (10–200 μg/mL) along with 20 μg/mL of CuNPs, was assessed against the Leishmania major (MRHO/IR/75/ER) amastigote forms and, then tested on cutaneous leishmaniasis induced in male BALB/c mice by L. major. Moreover, infectivity rate, nitric oxide (NO) production, and cytotoxic effects of CuNPs on J774-A1 cells were evaluated. Results: Scanning electron microscopy showed that the particle size of CuNPs was 17 to 41 nm. The results demonstrated that CuNPs, especially combined with MA, significantly (p < 0.001) inhibited the growth rate of L. major amastigotes and triggered the production of NO (p < 0.05) in a dose-dependent manner. CuNPs also had no significant cytotoxicity in J774 cells. The mean number of parasites was significantly (p < 0.05) reduced in the infected mice treated with CuNPs, especially combined with MA in a dose-dependent response. The mean diameter of the lesions decreased by 43 and 58 mm after the treatment with concentrations of 100 and 200 mg/mL of CuNPs, respectively. Conclusion: The findings of the present study demonstrated the high potency and synergistic effect of CuNPs alone and combined with MA in inhibiting the growth of amastigote forms of L. major, as well as recovery and improving cutaneous leishmaniasis (CL) induced by L. major in BALB/c mice. Additionally, supplementary studies, especially in clinical settings, are required.

Derivation of the economic value of R0 for macroparasitic diseases and application to sea lice in salmon

BackgroundMacroparasites, such as ticks, lice, and helminths, are a concern in livestock and aquaculture production, and can be controlled by genetic improvement of the host population. Genetic improvement should aim at reducing the rate at which parasites spread across the farmed population. This rate is determined by the basic reproduction ratio, i.e. {text{R}}_{0}, which is the appropriate breeding goal trait. This study aims at providing a method to derive the economic value of {text{R}}_{0}.MethodsCosts of a disease are the sum of production losses and expenditures on disease control. Genetic improvement of {text{R}}_{0} lowers the loss-expenditure frontier. Its economic effect depends on whether the management strategy is optimized or not. The economic value may be derived either from the reduction in losses with constant expenditures or from the reduction in expenditures with constant losses.ResultsWhen {text{R}}_{0} ≤ 1, the economic value of a further reduction is zero because there is no risk of a major epidemic. When {text{R}}_{0} > 1 and management is optimized, the economic value increases with decreasing values of {text{R}}_{0}, because both the mean number of parasites per host and frequency of treatments decrease at an increasing rate when {text{R}}_{0} decreases. When {text{R}}_{0} > 1 and management is not optimized, the economic value depends on whether genetic improvement is used for reducing expenditures or losses. For sea lice in salmon, the economic value depends on a reduction in expenditures with constant losses, and is estimated to be 0.065€/unit {text{R}}_{0}/kg production.DiscussionResponse to selection for measures of disease prevalence cannot be predicted from quantitative genetic theory alone. Moreover, many studies fail to address the issue of whether genetic improvement results in reduced losses or expenditures. Using {text{R}}_{0} as the breeding goal trait, weighed by its appropriate economic value, avoids these issues.ConclusionWhen management is optimized, the economic value increases with decreasing values of {text{R}}_{0} (until the threshold of {text{R}}_{0} = 1, where it drops to zero). When management is not optimized, the economic value depends on whether genetic improvement is used for reduced expenditures or production losses. For sea lice in salmon, the economic value is estimated to be 0.065 €/unit {text{R}}_{0}/kg production.

Urban and Forest-Living BlackbirdsTurdus merulaas Hosts ofBorreliellaspp. Infected Ticks

The effect of urbanisation on parasite prevalence, especially these associated with human diseases, such as Lyme borreliosis, is of high interest. The blackbird Turdus merula is a ground-feeding species particularly predisposed to constitute a Borreliella spp. (Lyme borreliosis causative agent) reservoir. So, the aim of the study was to examine if the tick infestation level and their Borreliella spp. infection prevalence differs in blackbirds resident in two disparate habitats in Poland – one highly urbanized (in Warsaw agglomeration) and the other forested (in Mazurian Lake region). The infection in ticks feeding on blackbirds was ascertained based on detection of bacterium DNA (PCR). The prevalence of tick infestation in urban and forest-living blackbirds was similar (90 and 91.7%, respectively) but the mean number of parasites per bird was markedly greater in the forest (4.0 ind.) than in the urban populations (1.5 ind.). Even though, the Borreliella spp. infection of the ticks was significantly greater in the urban (46.7%) than in forest habitat (35.4%). Additionally, in the urban site more birds carry at least one infected tick than in the forest. The results of the study seem to confirm the role of blackbirds in establishing Borreliella spp. reservoir. Special regard should be given to highly urbanized areas, where the relative increase in the relevance of birds as tick hosts and pathogen transmitters may pose high risk to public health. Thus, the study constitutes a small-scale but an important contribution to our understanding of the role of birds in maintenance of Borreliella spp. foci in urban habitats.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine.

Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Spatio-temporal variation in prevalence and intensity of trematodes responsible for waterfowl die-offs in faucet snail-infested waterbodies of Minnesota, USA.

Several non-native trematodes hosted by the invasive Eurasian faucet snail, Bithynia tentaculata, have been causing die-offs of waterfowl in the Midwestern United States and Canada for several decades. Because of the potential implications of these die-offs on waterfowl in non-native settings, it is necessary to better understand the trematodes that cause the die-offs. Here, we studied the spatio-temporal dynamics of two trematodes, Cyathocotyle bushiensis and Sphaeridiotrema spp., known to infect waterfowl in northern Minnesota, USA, via their intermediate host, the faucet snail (Bithynia tentaculata). We studied prevalence (% of snails infected within a sample) and intensity (mean number of parasites per infected snail within a sample) of faucet snail infection with these two trematodes in small lakes, large lakes, ponds, and rivers in northern Minnesota in the spring, summer, and fall of 2011–2013. We tested whether parasite prevalence and infection intensity could be explained spatially (as a function of the abundance of faucet snails, average snail size, water depth, and proximity to known waterfowl groups) and temporally (across years and seasons) using generalized estimating equation models. The spatial and temporal patterns we observed varied within and among waterbodies. For both parasite species, parasite prevalence and intensity of infection were consistently higher in samples with larger snails and in deeper portions of the waterbodies. In Lake Winnibigoshish, prevalence was lower farther from the large waterfowl groups we observed, but the abundance of snails in a sample had no effect on prevalence or intensity of infection. Our findings help improve understanding of this multi-species system, but also illustrate the complexity of modeling the spatial and temporal dynamics of infections in waterbodies that are so variable in size, shape, waterfowl use, and function.

The influence of commercial harvesting on parasite infection in the bivalve Austrovenus stutchburyi

Commercial harvesting often reduces densities of target species, potentially affecting transmission of parasites within the population. Rates of parasitic infection not only impact the hosts directly, but can result in wider ecosystem effects through influences on host behaviour. Commercial harvesting may therefore have important ecological consequences beyond the direct effects of removal of biomass. Clams (Austrovenus stutchburyi) are commonly infected by trematode parasites (Acanthoparyphium spp. and Curtuteria australis) and have been commercially harvested in Otago, New Zealand, since 1983. To assess the effects of harvesting on the abundance of trematodes in A. stutchburyi, the number of parasites per clam was compared in harvested and unharvested areas. The mean number of parasites per clam was 36% higher at commercially harvested sites, suggesting that harvesting enhances the local transmission of parasites. Harvesters may be able to reduce their influence on parasite infection levels in clam populations by harvesting less intensively and allowing more time between harvests for clam biomass to regenerate.

Antileishmanial, antioxidant, and cytotoxic activities of Quercus infectoria Olivier extract.

Currently, there is no effective vaccine available, and chemotherapy is the main approach for treatment of cutaneous leishmaniasis (CL). During recent decades, studies have demonstrated that a number of plant-derived compounds may act as new therapeutic tools against leishmaniasis. This study was evaluated the antileishmanial, antioxidant, and cytotoxic activities of Quercus infectoria Olivier (oak) extract. The total amount of phenolic and flavonoid compounds was measured in oak extract. High performance liquid chromatography (HPLC) analysis was also performed to determine the amount of quercetin and gallic acid in this plant. This extract (0-80g/mL) was evaluated in vitro against promastigote and intracellular amastigote forms of Leishmania major (MRHO/IR/75/ER) using MTT assay and in a macro-phage model, respectively. Then oak extract was tested on CL in infected male BALB/c mice with L. major in order to evaluate the antileishmanial activity topically. Moreover, cytotoxicity effects of oak in murine macrophage cells were tested by MTT assay. Antioxidative activity of oak was also determined by the 2,2-diphenyl-1,1-picrylhydrazyl (DPPH) scavenging test. The amount of phenolic and flavonoid compounds in the oak extract was 57.50 and 1.86%, respectively. The amount of quercetin and gallic acid in the oak extract was 0.0064 and 0.22%, respectively. The findings revealed that oak significantly (P<0.05) inhibited the growth rate of promastigote of (IC50 12.65μg/mL) and amastigotes (IC50 10.31μg/mL) as a dose-dependent response. In the in vivo assay, after 4 weeks of treatment, 91.6, 66.66, and 50% recovery was observed in the infected mice treated with 20, 10, and 5mg/kg of oak extract, respectively. After treatment of the infected mice with the concentration of 10 and 20mg/kg of oak, the mean diameter of lesions, parasite load and mean number of parasites was significantly (P<0.05) reduced. Selectivity index of greater than 10 for oak revealed that oak extract had no cytotoxic effects on macrophage cells. Moreover, DPPH test demonstrated that radical inhibition occurred at greater power with increasing the concentration of oak. To conclude, the present study showed potent antileishmanial and antioxidant activity of oak extract; whereas this plant had no toxic effect on mammalian cells.

Infection rates of Linguatula serrata nymphs in mesenteric lymph nodes from water buffaloes in North India

The literature pertaining to prevalence of Linguatula serrata in large ruminants is limited. In abattoir survey, the infection rate of L. serrata in 1440 mesenteric lymph nodes collected from 480 buffaloes from North India was investigated. Results revealed 88 (18.3%) buffaloes and 288 (20.0%) mesenteric lymph nodes having parasite's nymphs. Nonsignificant difference (P>0.05), between 1 and 3 years age (51.5%) and above three years of age (48.5%) groups was observed. Nonsignificant difference (P>0.05) between the infection rate of male (51.5%) and female (48.5%) was also observed. Infection in haemorrhagic (57.2%) and black-coloured (67.5%) nymph nodes were significantly (P<0.05) higher than normal-coloured nodes (8.8%). When compared based on consistency, the results showed soft lymph nodes (61.3%) were significantly (P<0.05) more infected than normal (12.8%) and hard (30.0%) lymph nodes. The intensity of infection in normal, haemorrhagic and black lymph nodes were 1.81±0.21, 4.23±0.0.62 and 5.12±0.73, nymphs respectively. The mean numbers of parasites in haemorrhagic and black-coloured lymph nodes were significantly (P<0.0005) more than mean number of parasites in normal-coloured nodes. Again intensity of infection in normal, soft and hard lymph nodes was 2.31±0.18, 5.84±0.74 and 3.21±0.68, respectively. When compared based on lymph nodes consistency, the soft lymph nodes were significantly (P<0.0005) more severely infected than normal and hard ones. The study has generated some vital data about the prevalence of this underreported disease amongst the bubaline intermediate hosts along with important gross changes in the affected lymph nodes.

ECOLOGICAL STUDY AND SUSCEPTIBILITY OF SOME APPLE VARITIES TO ATTACK BY Dysaphis reaumuri and Dysaphis pyri

The Results of studying the effect of some ecological factors and Ana and Vestibella apple varieties on seasonal activity of leafroll aphid Dysaphis reanmuri and Dysaphis pyri, showed a significant effect on mean number of the two aphid species a ccording to the season, apple variety and direction, the highest mean aphid number reached 25.47 Aphid/Leaf on East direction on Vestibella variety for the season 2010 The results also exhibit a significant variation between the general mean number of aphids according to the direction and reached 23.16, 9.62, 7.74 and 13.46 Aphid/leaf for East, West, North and South direction respectively. The regression equations between the mean number of aphids and biotic and abiotic factors showed a clear effect on mean aphid seasonal activity and the rain exhibit ahighest effect on mean aphid number and reached ٪66 – 6 while the effect of wind and temperature on mean number of parasites were 67. and 59.6% respectively.

Patterns of a novel association between the scyphomedusaChrysaora plocamiaand the parasitic anemonePeachia chilensis

Jellyfish display strong population variability. Competitive interactions between fish and jellyfish have been depicted as a major mechanism controlling this variability. Biological associations involving jellyfish are, however, more diverse than predation–prey interactions and remain poorly understood. Parasitic associations in particular may have relevant effects on jellyfish host populations. We studied basic patterns (temporal patterns of parasite intensity–biomass and the distribution pattern of parasites among hosts) of the association between the parasitic anemonePeachia chilensisand its scyphozoan host,Chrysaora plocamia. The mean number of parasites per host (MI) was high (average = 465) and showed significant differences during the pelagic life phase of the medusa. The mean biomass of parasites per host was also significantly different among months but showed a different temporal pattern to that of MI, which may reflect recruitment pulses of parasitic larvae. The mean biomass ofP. chilensisper host averaged 56.3 mg ash-free dry mass, which represents a trophic flow of energy probably linking pelagic and benthic food webs. The distribution of parasites among hosts was best fitted to the negative binomial distribution model, as typical for host–parasite systems. We concluded that the parasite-induced host mortality and reduction of fecundity, represented by parasitic castration, is restricted to a few hosts and is therefore under the expected levels that characterize the dynamic equilibrium of host–parasite systems.

A CROSS SECTIONAL STUDY ON &lt;i&gt;FASCIOLA GIGANTICA&lt;/i&gt; AND &lt;i&gt;GIGANTOCOTYLE EXPLANATUM&lt;/i&gt; BURDENS IN NATURALLY INFECTED BUFFALOES IN BANGLADESH

A cross sectional study on Fasciola gigantica and Gigantocotyle explanatum burdens in buffaloes in relation to their age, sex and health condition was carried out in the Laboratory of Parasitology, Bangladesh Agricultural University, Mymensingh, Bangladesh during the period from June to November 1997. A total of 460 faecal samples were examined to determine the egg per gram of faeces (epg) of F. gigantica. Higher epg was counted in female buffaloes (159.67 ± 6.80) than in males (153.24 ± 8.29). The epg counts were also found significantly (p &lt; 0.01) higher in poor conditioned buffaloes (164.41 ± 6.67) than in buffaloes with normal health (128.57 ± 7.08). In relation to age, the young adult buffaloes were found to bear more parasitic burdens. The highest mean epg was recorded in the buffaloes of 2-3 years old (184.21 ± 19.14), followed by 3-5 years old (169.23 ± 30.77). The older buffaloes had relatively lower parasitic burden and the lowest mean epg was recorded in the growing buffaloes of up to 1 year old (125 ± 25.0). Examination of 106 livers from slaughtered buffaloes, revealed that the load of Fasciola gigantica and Gigantocotyle explanatum in the livers ranged from 13-424 (69.20 ± 6.46) and 41-427 (161.45 ± 10.79) respectively. In males the burden of F. gigantica (13-210) was lower than that of the females (15-424). The mean number of F. gigantica in the buffaloes of 5- 10 years old (100 ± 15.32) was significantly higher (p &lt; 0.01) than those of the buffaloes of above 10 years old (52.92 ± 4.29). In case of single infection with F. gigantica, the mean number of parasites per liver was significantly (p &lt; 0.05) higher (88.70 ± 11.48) than that of mixed infection cases (49.74 ± 4.20). Significantly (p &lt; 0.01) higher number of G. explanatum was recovered from the buffaloes of 5-10 years old (207.53 ± 26.72) than from the buffaloes of above 10 years old (141.58 ± 9.23) and from single infected cases than from buffaloes with mixed infection. There were almost no differences in the number of both flukes in relation to sex of buffaloes. The length and breadth of immature and mature parasites were 5-15 min x 2-3 min and 16-72 mm x 4-14 mm respectively. No significant variation was found in the average size of F. gigantica in relation to the age and sex of buffaloes. But in case of single infection, the body size of mature F. gigantica (38.63 mm ± 0.38 mm x 9.96 mm ± 0.12 mm) was significantly (p &lt; 0.05) higher than that of the mixed infection (33.68 mm ± 0.52 mm x 8.76 mm ± 0.07 mm) cases. This study fairly suggests that the young adult buffaloes harbour more F. gigantica parasites than their younger and older counterparts. The concomitant infection of buffaloes with F. gigantica and G. explanatum may hamper the parasites each other in establishing their infection and attaining growth in some way as measured by their burdens and morphological dimensions.

In vitro evaluation of new terpenoid derivatives against Leishmania infantum and Leishmania braziliensis

The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug. The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.

Seasonal occurrence and site selection of Lamproglena pulchella Von Nordmann, 1832 (Copepoda, Lernaeidae) on the gills of rudd, Scardinius erythrophthalmus (Pisces, Cyprınidae)

The crustacean ectoparasite, Lamproglena pulchella Von Nordmann, 1832 (Copepoda, Lernaeidae) is found attached to the gill filaments of rudd, Scardinius erythrophthalmus (Linnaeus, 1758). During the present study, performed between March 2009 and February 2010 at monthly intervals at Lake Sapanca, Turkey, a total of 128 specimens of S. eryththrophthalmus were examined. Of these, 88 (68.8%) were infected by L. pulchella, which totalled 251 in number, with a mean intensity [mean number of parasites per infected fish] of 2.85 and a mean abundance [mean number of parasites calculated over all fish sampled] of 1.96 individuals. There was no distinct seasonality in the occurrence of L. pulchella throughout the study period. The maximum mean abundance of the infection was recorded as 2.84 individuals in July. The prevalence of L. pulchella increased with fish body size. The maximum intensity of the infection was 12 specimens of L. pulchella in July on a single fish. The branchial distribution of L. pulchella was studied and no preference was found in the distribution of the parasite between the gill arches on the left and right side. Gill arches II and III, medial segments, posterior hemibranches, and inner surface of the hemibranches were preferred by L. pulchella.

Longevity of Bolbophorus damnificus Infections in Channel Catfish

The digenean Bolbophorus damnificus infects commercial channel catfish Ictalurus punctatus, causing mortality, lower feed consumption, and reduced growth in surviving fish. The purpose of this study was to determine the length of time for which B. damnificus prodiplostomulum metacercariae (juvenile trematode stage that infects fish) would remain viable (parasite appearing to be intact or exhibiting movement) in channel catfish. Fish (n = 210) were infected with molecularly confirmed B. damnificus cercariae harvested from naturally infected marsh rams-horn snails Planorbella trivolvis. During the first sampling (at 20 d postinfection), 8.3 +/- 3.6 metacercariae/fish (mean +/- SD) were found in the host muscle and visceral organs. The channel catfish were then acclimated to a water temperature of either 18 degrees C or 28 degrees C. After 11 months, 6.8 +/- 3.5 and 5.9 +/- 3.0 metacercariae/fish were found in groups held at 18 degrees C and 28 degrees C, respectively. The mean number of parasites per fish did not significantly differ between fish held at the two temperatures and did not significantly decline over time at either temperature. Fish examined from 13 to 30 months postinfection all contained viable metacercariae that were morphologically and molecularly identified as B. damnificus. At 18 months, 12 metacercariae (of which 11 were intact and 10 displayed movement) were found in the one fish sampled; at 30 months, the last fish sampled contained three intact metacercariae (one displayed slight movement). Our results indicate that B. damnificus metacercariae can remain viable in channel catfish for at least an 18-30-month production cycle during which they have the potential to affect fish growth; in addition, infected fish may serve as intermediate hosts for these metacercariae for at least 2.5 years postinfection.

Detection ofToxoplasmaDNA in the Peripheral Blood of HIV-Positive Patients with Neuro-opportunistic Infections by a Real-Time PCR Assay

We determine if peripheral blood sample could be used for diagnosis of cerebral toxoplasmosis by a real-time PCR assay and we analyzed the clinical and laboratory findings in 22 patients with confirmed cerebral toxoplasmosis compared to 27 patients with other neuro- opportunistic infections. We compared two gene targets (B1 and RE) in the Taqman-PCR real-time assay. Efficiency values were also calculated. We found that 18.8% (4/22) of cases with cerebral toxoplasmosis and 7.4% (2/27) of patients with other neuroinfections had positive results with the Taqman PCR assay. The mean number of parasites was 67.7 (SD 69.0) tachyzoites/mL in patients with cerebral toxoplasmosis and of 31.8 (SD 6.3) tachyzoites/mL in other neuroinfections. Clinical symptoms as headache were significantly less frequent and focal neurological symptoms were significantly more frequent in cerebral toxoplasmosis than in other neuroinfections. In our conditions, real- time PCR on peripheral blood samples was not useful for diagnosis of cerebral toxoplasmosis.