THE PHARMACOKINETICS AND PHARMACODYNAMICS OF ORAL PONAZURIL IN THE TREATMENT OF SYSTEMIC ISOSPOROSIS IN PASSERINE BIRDS

Systemic isosporosis, previously atoxoplasmosis, is a significant cause of mortality in juvenile passerine birds. Recommended treatment regimens are empiric and vary in efficacy. The goal of this study was to determine the pharmacokinetics and pharmacodynamics of ponazuril for treatment of systemic isosporosis. Ponazuril, diluted with water to create an oral suspension (50 mg/ml), was administered (100 mg/kg) to 72 European starlings (Sturnus vulgaris) by a single dose via direct oral gavage (n = 24), a single dose injected into superworm larvae (Zophobas morio; n = 24), or a daily dose mixed with commercial dog food to top-dress feed for 5 d (n = 24). Peak plasma concentrations were 5.84, 2.46, and 9.13 µg/ml for the direct gavage, injected larvae, and top-dressed feed groups, respectively. With repeated dosing, mean plasma concentrations from the top-dressed feed group were maintained between 8.12 to 13.11 µg/ml. Results suggested ponazuril at a dosage of 100 mg/kg administered via direct gavage or top-dressed feed, but not via injected larvae, would exceed the concentrations needed to inhibit merogony of other apicomplexan parasites in cell culture (5 µg/ml). To assess the pharmacodynamics of this dose, seven passerine birds, red-vented bulbuls (Pycnonotus cafer; n = 2), blue-grey tanager (Thraupis episcopus; n = 1), and red-capped cardinals (Paroaria gularis; n = 4), were identified as shedders of systemic Isospora spp. via fecal qPCR. Birds were then treated with ponazuril (100 mg/kg) daily on top-dressed feed for 14 d. Fecal shedding was assessed via qPCR for 6 wk from the initiation of treatment. Treatment was associated with reduction in proportions of fecal shedding during the treatment period and the week following treatment, but shedding resumed in all birds by the end of sampling. Results support that treatment of breeding birds with 100 mg/kg ponazuril could reduce the shedding of active oocysts and decrease risk of clinical infection in susceptible juveniles.

Morphological and molecular characterization of Isospora amphiboluri (Apicomplexa: Eimeriidae), a coccidian parasite, in a central netted dragon (Ctenophorus nuchalis) (De Vis, 1884) in Australia

An Isospora species, Isospora amphiboluri, originally described by Canon in 1967 and later by McAllister et al. (1995), was isolated from a central netted dragon (Ctenophorus nuchalis) housed at a wildlife rehabilitation centre in Perth, Western Australia. Sporulated oocysts of Isospora amphiboluri (n = 30) are spherical, 24.2 (26.5-23.0) μm in length and 23.9 (22.4-25.9) μm in width, with a shape index of 1.01. The bilayered oocyst wall is smooth and light-yellow in color. Polar granule, oocyst residuum and micropyle are absent. The sporocysts are lemon-shaped, 15.7 (15.2-18.0) × 10.2 (8.9-11.2) μm, with a shape index (length/width) of 1.53. Stieda and substieda bodies are present, the Stieda body being small and hemidome-shaped and the substieda half-moon-shaped. Each sporocyst contains four vermiform sporozoites arranged head to tail. The sporozoites are 11.7 (9.9-16.2) × 3.0 (2.4-3.5) μm, with a shape index (length/width) of 3.87. A sporocyst residuum is present. Sporozoites contain a central nucleus with a finely distributed granular residuum. Comparison of oocyst measurements and their features with other valid Isospora species from hosts in the Agamid family confirmed that this Isospora species is Isospora amphiboluri. Molecular characterization of I. amphiboluri at the 18S rRNA and MTCOI loci showed the highest similarity with I. amphiboluri from the central bearded dragon, 99.8% and 99.7% respectively. This is the first report of I. amphiboluri from a central netted dragon in Australia.

Morphological and molecular description of a new species of Isospora (Apicomplexa) from a New Holland honeyeater (Phylidonyris novaehollandiae)

A new Isospora species is described from New Holland honeyeaters (Phylidonyris novaehollandiae). Sporulated oocysts (n = 25) were characterised as subspheroidal, 29-32 × 28-31 (29.8 × 29.4); length/width (L/W) ratio 1.01-1.02 (1.01). Wall bi-layered, 1.3-1.6 (1.5) thick, outer layer smooth, c.2/3 of total thickness. Micropyle and oocyst residuum absent, but usually two polar granules are present. Sporocysts (n = 25) ovoidal, 18-19 × 12-14 (18.4 × 12.3); L/W ratio 1.42-1.53 (1.50). Stieda body present, flattened, c.0.5 deep × 2.5 wide; sub-Stieda present, rounded, c.2.5 deep × 3.5 wide; para-Stieda body absent; sporocyst residuum present, usually a distinctly irregular body consisting of numerous small granules that appear to be membrane-bound. Sporozoites vermiform, with robust anterior and posterior refractile bodies. Molecular characterization was conducted at the 18S and 28S ribosomal RNA and the mitochondrial (mt) cytochrome oxidase (COI) loci. Phylogenetic analysis of genomic 18S and mt COI sequences indicated that Isospora phylidonyrisae n. sp. was genetically similar to Isospora coronoideae, isolated from an Australian raven (Corvus coronoides) in Western Australia, with a 99.3% and 98.4% homology, respectively. The 28S rRNA sequence was most similar to Isospora anthochaerae (KF766053) and Isospora manorinae (KT224381), both with a 98.2% genetic similarity. Based on morphological and genetic data, this isolate is a new species of Isospora, which is named Isospora phylidonyrisae n. sp. after its host.

Epithelial Inclusions in Gallbladder Specimens Mimic Parasite Infection: Histologic and Molecular Examination of Reported Cystoisospora belli Infection in Gallbladders of Immunocompetent Patients

Recent publications have described epithelial cytoplasmic vacuoles and inclusions incidentally noted within gallbladder epithelium and concluded that they represent coccidian parasite infection, in particular, Cystoisospora belli. We identified 8 gallbladder specimens from our institution in the past 3 years in which this diagnosis was suggested or in which similar epithelial alterations were prominent. Molecular analysis was performed on the 8 gallbladder specimens and on 3 positive control specimens: small bowel biopsies from acquired immunodeficiency syndrome patients with diarrhea. Polymerase chain reaction using primers designed to amplify an internal transcribed spacer (ITS2) in the C. belli ribosomal gene cluster was performed on the DNA samples. All 8 gallbladder specimens were negative for amplification, while a product consistent with C. belli was amplified from all 3 positive controls. Histologically, the gallbladder cytoplasmic inclusions stained diffusely positive for Grocott-Gomori's methenamine silver and Periodic acid-Schiff with diastase. In contrast, sections from a positive control small bowel biopsy demonstrated organisms that were negative for Grocott-Gomori's methenamine silver and showed a distinct capsular and punctate internal staining on Periodic acid-Schiff with diastase in various parasite forms. Together, the lack of molecular evidence of C. belli and the distinct morphologic and special staining patterns in these gallbladders compared with positive control small bowel suggest that these epithelial changes do not represent true C. belli infection. Our results suggest that gallbladders of immunocompetent patients may occasionally show epithelial changes that can morphologically mimic C. belli infection. Pathologists should be aware of this histologic variant to minimize unnecessary treatment, testing, and patient anxiety.

The ruby-crowned tanager Tachyphonus coronatus Vieillot, 1822 (Passeriformes: Thraupidae) as a new host for Isospora ramphoceli Berto, Flausino, Luz, Ferreira, Lopes, 2010 in Brazil

Despite 12 coccidian species had been recorded from passerines of the Thraupidae family, none of them has been reported in the Parque Nacional do Itatiaia, in Southeastern Brazil. This locality is a protected area with a high degree of vulnerability, and is considered a "conservation island" of biodiversity. The aim of the current work was describe Isospora ramphoceli Berto, Flausino, Luz, Ferreira, Lopes, 2010 from ruby-crowned tanagers Tachyphonus coronatus Vieillot, 1822 in the Parque Nacional do Itatiaia. The oocysts of I. ramphoceli are subspheroidal, 23.1 × 22.1 μm, with smooth, bilayered wall. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ellipsoidal or ovoidal, 16.2 × 10.8 μm. Stieda body is knob-like and substieda body is large and homogeneous. Sporocyst residuum is composed of many scattered granules. Sporozoites are vermiform with a posterior refractile body and a nucleus. In addition to new locality, this is the first description of I. ramphoceli from T. coronatus.

Coprology of a single Northern white-breasted hedgehog (Erinaceus roumanicus): first report of Isospora rastegaievae in Poland

Coprological analysis of a sample from one free-living hedgehog was done with the use of a direct flotation method with additional incubation of fecal material. The study revealed three types of eggs and oocysts in the feces. The most commonly diagnosed were oocysts of Isospora rastegaievae (543/3g), while oocysts of Monocystis sp. (267/3g) and eggs of Aonchotheca/Eucoleus spp. (52/3g) were seen less often. This is the first report of coccidia I. rastegaievae (Apicomplexa: Eimeriida) and acephaline gregarine Monocystis sp. (Apicomplexa: Eugregarinida) infection in a hedgehog in Poland.

Morphological and molecular characterization of Isospora neochmiae n. sp. in a captive-bred red-browed finch (Neochmia temporalis) (Latham, 1802)

A new Isospora (Apicomplexa: Eimeriidae) species is described from a single red-browed finch (Neochmia temporalis) (subspecies N. temporalis temporalis), that was part of a captive population in Western Australia. Sporulated oocysts of this isolate are spherical, 18.3 (18.2-18.9) × 18.2 (18.2-18.6) μm, with a shape index (length/width) of 1.0; and a smooth and bilayered oocyst wall, 1.2 μm thick (outer layer 0.9 μm, inner 0.3 μm). A polar granule is present, but the oocyst residuum and a micropyle are absent. The sporocysts are ovoid-shaped, 13.3 (9.5-16.4) × 8.6 (6.8-10.0) μm, with a shape index of 1.5. An indistinct Stieda body is present, but the substieda body is absent. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites. Morphologically, the oocysts from this isolate are different from those of all known valid Isospora spp. Molecular analysis was conducted at 4 loci; the 18S and 28S ribosomal RNA (rRNA), the mitochondrial cytochrome oxidase (COI) gene and the heat shock protein 70 (hsp70) gene. At the 18S locus, this new isolate exhibited 99.9%, 99.8%, 99.7%, and 99.5% similarity to I. sp. MAH-2013a from a superb starling (Lamprotornis superbus), I. MS-2003 from a Southern cape sparrow (Passer melanurus), I. sp. Tokyo from a domestic pigeon (Columba livia domestica) and I. MS-2003 from a Surinam crested oropendula (Psarocolius decumanus). At the 28S locus, this new isolate exhibited 99.7% similarity to both an Isospora sp (MS-2003) from a Northern house sparrow (Passer domesticus) and an Isospora sp. (MS-2003) from a Southern cape sparrow. At the COI locus, this new isolate exhibited 98.9% similarity to an Isospora sp. ex Apodemus flavicollis. At the hsp70 locus, this new isolate exhibited 99% similarity to isolate MS-2003 (AY283879) from a wattled starling (Creatophora cinerea). Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora neochmiae n. sp. after its host, the red-browed finch (Neochmia temporalis).

Molecular Identification of Biliary Isospora Belli: A Case Report

This report describes the novel sampling of bile from the biliary endoscopic intervention for the molecular identification of parasite infection.A 63-year-old Vietnamese man underwent travel health examination in our hospital. Physical examination showed that his height was 159 cm and weight was 41 kg. He had a 15-year history of intermittent abdominal pain and frequent episodes of diarrhea. Laboratory tests revealed raised eosinophil count (23%, normal range [NR] 0-5), absolute eosinophil count (1899/μL, NR 50-350), and levels of serum immunoglobulin E (3770 IU/mL, NR < 100), aspartate transaminase (270 U/L, NR 0-37), alanine transaminase (210 U/L, NR 0-40), and total bilirubin (1.8 mg/dL, NR 0.2-1.4); however, the serum alkaline phosphatase level was normal (65 U/L, NR 28-94) and non-reactive result for serum human insufficiency virus antibody.Magnetic resonance cholangiopancreatography revealed diffuse dilatation of the biliary tree; the common hepatic and pancreatic duct diameters increased to 1.86 cm and 0.61 cm, respectively.Endoscopic retrograde cholangiopancreatography was performed and a 10-Fr model plastic biliary stent was inserted and flushed with 20 cc normal saline; thereafter, the bile was collected and sent for DNA sequencing. Isospora belli (IB) infection was identified by a polymerase chain reaction.Trimethoprim-sulfamethoxazole 800 mg q6h was administered for 1 month. Liver enzyme levels normalized and negative for concentration method of ova study. The patient was doing well and weighed 51 kg at the outpatient clinic visit 3 months later.This bile sampling with molecular identification has not been described in the literature. We believe that an acute IB infection through fecal-oral transmission may progress to chronic infection of the hepatobiliary system, leading to biliary obstruction and jaundice.

Factors associated with the occurrence and level of Isospora suis oocyst excretion in nursing piglets of Greek farrow-to-finish herds

BACKGROUND

Piglet isosporosis is one of the most common parasitic diseases in modern pig production. To prevent clinical disease, prophylactic treatment of piglets with toltrazuril (BAYCOX® 5%, Bayer HealthCare, Animal Health, Monheim, Germany) is widely practiced in the past 20 years. There are only very few reports documenting the likely effect of managerial practices, such as hygiene measures, all-in-all-out management of farrowing facilities and piglet manipulations, and/or farm-specific environment - i.e. design and materials of the farrowing pen and room - in the risk of disease occurrence and transmission. Therefore, in this cross-sectional study, we identified litter- and herd-level factors associated with the odds and the level of Isospora suis oocyst excretion in nursing piglets of Greek farrow-to-finish pig herds. Faecal samples were collected from 314 liters of 55 randomly selected herds. Oocyst counts were determined by a modified McMaster technique and possible risk-factor data were collected through a questionnaire. In the analysis, we employed a two-part model that simultaneously assessed the odds and the level of oocyst excretion.

RESULTS

Factors associated with lower odds of oocyst excretion were: use of toltrazuril treatment, all-in all-out management of the farrowing rooms, no cross-fostering or fostering during the first 24 hours after farrowing, plastic flooring in the farrowing pens, farrowing rooms with more than fourteen farrowing pens and employment of more than two caretakers in the farrowing section. Factors associated with lower oocyst excretion level were: use of toltrazuril treatment and caretakers averting from entering into farrowing pens.

CONCLUSION

Apart from prophylactic treatment with toltrazuril, the risk and the level of I. suis oocyst excretion from piglets in their second week of life, was associated with managerial and environmental factors. Changes in these factors, which may enhance prevention of piglet isosporosis - either alternatively or supplementary to medical control - are of increasing importance because of the likely development of resistant parasites under the currently widespread use of anticoccidial compounds.

Failure to eradicate Isospora belli diarrhoea despite immune reconstitution in adults with HIV--a case series

Isospora belli causes diarrhoea in patients with AIDS. Most respond to targeted therapy and recommendations are that secondary prophylaxis can be stopped following immune reconstitution with ART. We report eight cases of chronic isosporiasis that persisted despite standard antimicrobial therapy, secondary prophylaxis, and good immunological and virological response to ART. Median CD4 nadir was 175.5 cells/mm(3) and median highest CD4 while symptomatic was 373 cells/mm(3). Overall 34% of stool samples and 63% of duodenal biopsy specimens were positive for oocytes. Four patients died, two remain symptomatic and two recovered. Possible explanations for persistence of symptoms include host factors such as antigen specific immune deficiency or generalised reduction in gut immunity. Parasite factors may include accumulating resistance to co-trimoxazole. Research is required to determine the optimum dose and duration of co-trimoxazole therapy and whether dual therapy may be necessary. Mortality was high and pending more data we recommend extended treatment with high-dose co-trimoxazole in similar cases.

Isospora piacobrai n. sp. (Apicomplexa: Eimeriidae) from the masked yellowthroat Geothlypis aequinoctialis (Gmelin) (Passeriformes: Parulidae) in South America

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) obtained from masked yellowthroat Geothlypis aequinoctialis (Gmelin) is reported from Brazil. Isospora piacobrai n. sp. has oöcysts which are subspheroidal to ovoidal, measure 15.8 x 10.5 microm and have a smooth, bilayered wall c. 1.2 microm thick. A micropyle and oöcyst residuum are absent, but a polar granule is present. Its sporocysts are ovoidal and measure 15.8 x 10.5 microm. The Stieda body is knob-like and prominent, the substieda body large, trapezoidal and homogeneous, and the sporocyst residuum composed of granules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. This is the first description of an isosporoid coccidian infecting a bird of the family Parulidae.

Severe diarrhea due to Isospora belli in a patient with thymoma

Opportunistic isosporidial infection of the gastrointestinal tract is frequently encountered in patients with acquired immunodeficiency syndrome (AIDS) and is considered to be an AIDS-defining illness. Chronic severe watery diarrhea due to Isospora belli has also been reported in other immunodeficiency states. This report describes severe chronic debilitating diarrhea due to isosporiasis in a patient with mediastinal thymoma, a common tumor of the anterior mediastinum, originating from the epithelial cells of the thymus. Numerous oocysts of I. belli were detected in direct smear preparation of the diarrheic stool sample of the patient, who had an 8-month history of recurrent diarrhea. Duodenal and colonic mucosal biopsies revealed slight degrees of atrophic changes associated with infiltration of the lamina propria by an appreciable number of eosinophiles and the presence of unizoit tissue cysts of I. belli in the surface epithelium of the duodenal mucosa. The patient was first treated with trimethoprim-sulfamethoxazole and subsequently underwent complete thymectomy. Later, due to recurrence of the diarrhea, he was treated with ciprofloxacin.

Validity of Isospora lacazei (Labbé, 1893) infecting the house sparrow, Passer domesticus (L.), in Saudi Arabia

Isospora lacazei was described from large number of passeriform birds including house sparrow (Passer domesticus). It was not certain whether all described species under this name belong to the same species. Also, two other species (Isospora passeris and Isospora passerum) were identified from P. domesticus depending on variation of oocyst measurements. During the present study, the Isospora species was reported from house sparrow (P. domesticus) in Saudi Arabia. The oocyst measurement ranges cover all the ranges of the previously described Isospora species from P. domesticus. Therefore, the present species could be identified as I. lacazei, whilst the other species being described can be considered as a junior synonym of I. lacazei.

Isospora plectrophenaxia n. sp (Apicomplexa: Eimeriidae), a new coccidian parasite found in Snow Bunting (Plectrophenax nivalis) nestlings on Spitsbergen

Faecal samples were collected from four 8 days old snow bunting nestlings from one nest in Ny-Alesund, Spitsbergen, in summer 2006. After sporulation, samples were examined for coccidian parasites using flotation centrifuging. We found isosporan oocysts in three birds, intensity of infection varied between individuals from 35 to 6,000 oocysts per defecation. All oocysts belonged to one species, which is described here as a new species. The spherical or subspherical oocysts (Fig. 1) have a brownish, smooth, relatively thin (about 1.1 microm) bilayered wall. Average size of sporulated oocysts was 26.2 +/- 0.13 x 23.6 +/- 0.16 microm (24.1-28.4 x 21.5-26.9; n = 10) with a shape index (length/width) of 1.11 +/- 0.01 (1.01-1.29). The sporulated oocysts have no micropyle or residuum but enclose one large (3.3 x 2.8 microm) ring-formed polar granule. The sporocysts are ovoidal, slightly pointed at the end opposite the Stieda body, 18.2 +/- 0.06 x 9.9 +/- 0.03 microm (17.1-19.0 x 9.0-10.8; n = 14), shape index 1.85 +/- 0.008 (1.70-1.99). The Stieda body has a prominent knob-like cap and a well-visible round substieda body. Sporocysts contain compact sporocyst residuum composed of small, uniform granules and sporozoits with usually three large refractile bodies and a smaller nucleus. The prepatent period is less than 8 days. This is the first description of an avian isosporan parasite that succeeds transmission while in the High Arctic.

CYSTOISOSPORA CANIS NEMESÉRI, 1959 (SYN. ISOSPORA CANIS), INFECTIONS IN DOGS: CLINICAL SIGNS, PATHOGENESIS, AND REPRODUCIBLE CLINICAL DISEASE IN BEAGLE DOGS FED OOCYSTS

Canine intestinal coccidiosis is a cause of diarrhea in young dogs and dogs that are immunocompromised. Reports in the literature indicate that experimental reproduction of clinical coccidiosis with Cystoisospora canis (syn. Isospora canis) is difficult, and few studies have been done with C. canis. Experimental oral infections were attempted in 22, 6- to 8-wk-old female beagles with 5 x 10(4) (n = 2) or 1 x 10(5) (n = 20) sporulated C. canis oocysts. Diarrhea was observed in all inoculated dogs. Diarrhea began 2-3 days before oocyst excretion. Five of the 22 dogs were given an anticoccidial (sulfadimethoxine) because of their clinical signs. The mean prepatent period was 9.8 days (range, 9-11 days, n = 22 dogs), and the patent period was 8.9 days (range, 7-18 days, n = 20 dogs). Two dogs exhibiting clinical coccidiosis were examined at necropsy 10 days after infection. Developmental stages of C. canis were present in cells in the lamina propria throughout the entire small intestine in both dogs. Microscopic lesions observed in both of these dogs were villous atrophy, dilation of lacteals, and hyperplasia of lymph nodes in Peyer's patches. Results of bacterial and viral examinations of these 2 dogs were negative, indicating that intestinal coccidiosis was the cause of the diarrhea. Our study indicates that C. canis can be a primary cause of diarrhea in young dogs.

Control of piglet coccidiosis by chemical disinfection with a cresol-based product (Neopredisan 135-1®)

Isospora suis is a common pathogen in piggeries and one of the main causative agents of scours in suckling piglets. Besides specific treatment, optimised hygiene including chemical disinfection is considered essential in the control of isosporosis. The suitability of the cresol-based product Neopredisan 135-1(R) (NP) to inactivate oocysts in vitro and to reduce infection pressure in commercial piggeries was evaluated. Under in vitro conditions, NP at a final concentration of 2 or 4% induced lysis of more than 95% of sporulated oocysts at a contact time of 30 min and destroyed all oocysts after a contact time of 90 min or more. A total of six trials (T1-T6) were performed on two farms (I and II). T5 was split into two parts, T5/1 and T5/2. Two groups of litters kept in farrowing crates either disinfected conventionally before farrowing (controls, group C) or disinfected with 4% dilution of NP before farrowing and with 2% NP one to three times thereafter (group NP) were compared in each trial. Altogether, 81 litters were randomly allocated to group NP and 77 litters to group C (comprising a total of 1,465 piglets). Piglet faeces were collected individually 5 days after birth and six times thereafter in intervals of 2 or 3 days from four piglets per litter and microscopically examined for oocysts of I. suis. Diarrhoea scores, other clinical data (skin turgidity, coat length etc.), weights and loss of piglets until weaning were recorded. One trial (T3) could not be analysed because of insufficient cleaning before disinfection. In group C, litter prevalence of I. suis ranged between 40 and 80%. The proportion of positive litters was considerably reduced by approximately 50% in disinfected crates except for one trial, and the number of affected piglets decreased by up to 80%. Diarrhoea and oocyst excretion were significantly associated. Diarrhoea was less frequently observed in disinfected crates. In general, isosporosis appeared mild to subclinical, and no significant effects of disinfection on other clinical data, weight gain and number of weaned piglets were noted. It is concluded that NP efficiently inactivates oocysts of I. suis, and that additional disinfection after farrowing is suited to reduce infection pressure. No clear relation of infection prevalence to the frequency of intermediate disinfection (one, two or three times) was seen, and thus, single intermediate disinfection 1 week after farrowing is considered sufficient.

Study on the species-specificity of Isospora michaelbakeri by experimental infection

Isospora michaelbakeri is one of the Isospora species most commonly found in the wild field, which can cause severe infection and mortality in young sparrows. In this study, we selected I. michaelbakeri (Chung Hsing strain) as a pathogen to orally inoculate russet sparrows (Passer rutilans), spotted munia (Lonchura punctulata), canary (Serinus canaria), Java sparrows (Padda oryzivora), chicken (Gallus domesticus), ducks (Anas platyrhynchos) and BALB/c mice. The results indicated that I. michaelbakeri infected only russet sparrows. Infected sparrows displayed lethargy, muscular weakness and fluffy feathers, followed by rapid death. Liver and spleen enlargement was seen in the infected birds. Schizonts were identified in thin smears from the venous blood, enlarged livers and spleens. Histopathological examination revealed schizonts and merozoites from the liver and spleen of infected russet sparrows, but not from other species experimentally inoculated with I. michaelbakeri in the present study.

[Comparison of different methods for examining the feces of suckling piglets for Isospora suis]

A highly sensitive diagnostic method is of great importance for detection of I. suis (Isospora suis). In the present study KSFV (combined sedimentation-flotation method) using different flotation solutions (NaCl, ZnSO4, NaCl-sucrose) was investigated regarding sensitivity, costs and expenditure of human labour in comparison to FV (flotation method) using NaCl-sucrose solution and to AM (autofluorescence microscopy). Ninety faecal samples were examined. Using AM, oocysts were detected in 83.3% of the samples. In cases of KSFV and FV, respectively, 41.1% to 53.3% of samples were tested positive. The quantity of detected oocysts was markedly higher in AM than in KSFV or FV. Therefore AM is the most sensitive of the comprised methods. The expenditure of labour is lowest in AM, time exposure is lower in FV than in KSFV. For performance of AM a fluorescence microscope is required contrary to KSFV and FV.

[Isospora belli infection in a patient with a renal transplant]

Isospora belli infection is frequent in immunosuppressed patients and can cause wasting diarrhea. We present the first isosporiosis case in a renal transplant recipient from Turkey. The 25-year old male patient who had had a renal transplantation due to renal failure and had received immunosuppressive therapy presented at the hospital complaining of weakness, nausea, vomiting and diarrhea that had lasted for 15 days. Isospora belli oocysts were detected in stool samples by direct microscopy, modified Ziehl-Neelsen staining methods and autofluorescence technique. Oocysts in the stool samples were also sporulated in 2.5% potassium dichromate and the sporulated oocysts were seen microscopically. The patient was treated with co-trimoxazole (trimethoprim 160 mg, sulphamethoxazole 800 mg) every 12 hours for seven days, with elimination of the symptoms at this time. After this, Isospora belli oocysts were no longer seen in stool samples.

The Genus Atoxoplasma (Garnham 1950) as a Junior Objective Synonym of the Genus Isospora (Schneider 1881) Species Infecting Birds and Resurrection of Cystoisospora (Frenkel 1977) as the Correct Genus for Isospora Species Infecting Mammals

Molecular and morphological data permit a rational subdivision of the paraphyletic Isospora into 2 apparently monophyletic groups of parasites, i.e., Isospora and Cystoisospora. Atoxoplasma was determined to be a junior objective synonym for Isospora. Tetrasporozoic, diplosporocystic oocysts possessing Stieda bodies in their sporocysts belong to Isospora (Eimeriidae) and have been described principally from the feces of birds. Tetrasporozoic, diplosporocystic oocysts without Stieda bodies in their sporocysts belong to Cystoisospora (Sarcocystidae).

Refractory isosporiasis

The authors describe a case of severe debilitating diarrhea due to isosporiasis in a two year old child, a known case of systemic vasculitis receiving prolonged corticosteroids therapy, an association rarely reported previously. It was refractory to treatment with dihydrofolate reductase inhibitor combined with sulfonamide such as cotrimoxazole to which isosporiasis usually responds well and is being described here for clinical interest and uniqueness of its presentation and laboratory findings.

Isospora belli infection in a patient with non-Hodgkin's lymphoma

Isospora belli infection is frequent in patients with acquired immunodeficiency syndrome in tropical areas. It has also been reported in other immunodepressive diseases, such as lymphoblastic leukemia, adult T-cell leukemia, and Hodgkin's disease. To date, no case of non-Hodgkin's lymphoma-related isosporiasis has been reported in a non-HIV-infected patient. We describe a case of non-Hodgkin's lymphoma with chronic diarrhea due to I. belli. In Europe, I. belli can cause severe chronic diarrhea in patients with malignancies whose country of origin is in an endemic area. Trimethoprim-sulfamethoxazole can provide rapid and prolonged clinical and parasitologic cure.

Isospora belli Infection: Observation of Unicellular Cysts in Mesenteric Lymphoid Tissues of a Brazilian Patient with AIDS and Animal Inoculation

We describe the finding of unizoic cysts of Isospora belli in lymphoid tissues of a Brazilian patient with AIDS, and discuss the possibilities of their drug resistance, they being the cause of relapses, and of being an indication for the existence of intermediary or paratenic animal hosts.

Recurrent isosporiasis over a decade in an immunocompetent host successfully treated with pyrimethamine

Recurrent isosporiasis in an immunocompetent host is reported. The patient suffered from chronic intermittent diarrhea for over a decade. Multiple short-term administrations of trimethoprim-sulfamethoxazole followed by pyrimethamine, or albendazole combined with tinidazole could not control the relapses. However, treatment with pyrimethamine, 25 mg/d for 20 weeks, was successful.

Evaluation of lacto-phenol cotton blue (LPCB) for detection of Cryptosporidium, Cyclospora and Isospora in the wet mount preparation of stool

Lacto-phenol cotton blue (LPCB) was found to be a useful stain for detection of Cyclospora and Isospora oocysts in direct wet mounts of stool. LPCB stained these parasites blue, and differentiated their internal structures clearly, thereby facilitating detection and accurate identification of these parasites. However, the LPCB staining was not found useful in the identification of Cryptosporidium. The LPCB wet mount is recommended for use in the laboratories where acid-fast staining is not performed routinely, such as in a peripheral laboratory or in a rural health centre in the developing countries.

Clinical large intestinal coccidiosis in camels (Camelus dromedarius) in the United Arab Emirates: description of lesions, endogenous stages, and redescription of Isospora orlovi, Tsygankov, 1950 oocysts

Between January and March 2001, eight 4- to 8-wk-old camels (Camelus dromedarius) from 2 farms from Dubai area of the United Arab Emirates were submitted for necropsy examination. The camels had diarrhea of 2-5 days duration. Grossly, a severe diphtheroid-to-hemorrhagic colitis was seen in all animals. Gamonts, unsporulated oocysts, sporulating oocysts, and fully sporulated oocysts were present in the intestinal epithelium and the lamina propria. Fully sporulated oocysts contained 2 sporocysts and 4 sporozoites in each sporocyst. Oocysts from fecal samples resembled oocysts of Isospora orlovi. This is the first report of an isosporan parasite associated with hemorrhagic enteritis in the large intestine of any animal.

Intestinal parasites in HIV-2 associated AIDS cases with chronic diarrhoea in Guinea-Bissau

Previous studies from African countries where HIV-1 infection is prevalent have shown that infections with Cryptosporidium parvum, Isospora belli and microsporidia are frequently associated with chronic diarrhoea in AIDS patients. The information about the occurrence of these parasites in HIV-2 associated AIDS cases with chronic diarrhoea is limited. We have performed a study of stool parasites in patients from Guinea-Bissau, the country with the highest prevalence of HIV-2 in the world. Stool specimens from 52 adult patients with chronic diarrhoea of which 37 were HIV-positive and fulfilling the clinical criteria of AIDS (five HIV-1, 28 HIV-2 and four dually infected with HIV-1 and HIV-2) were screened for parasitic infections. Twenty five percent of the HIV-2 positive patients were infected with C. parvum, 11% with I. belli and 11% with microsporidia, all three parasites were seen only in HIV-positive patients. The three patients with microsporidiosis, all HIV-2 infected, are to our knowledge the first cases reported from Guinea-Bissau. Other stool parasites such as Blastocystis hominis, hookworm and Strongyloides stercoralis were observed both among HIV-positive and HIV-negative patients.

Five new species of coccidia (Apicomplexa: Eimeriidae) from Madagascan chameleons (Sauria: Chamaeleonidae)

Coprological examination of 19 Madagascan chameleons of the genera Furcifer and Brookesia revealed the presence of five new coccidian species. Isospora brygooi n. sp. from Furcifer pardalis has spherical to subspherical oöcysts with a slightly pitted wall, 20.7 (17-24.5) x 19.3 (16-23) microm and broadly ellipsoidal sporocysts, 12.2 (11.5-13) x 8.1 (8-8.5) microm, with Stieda and substieda bodies. Oöcysts of Eimeria glawi n. sp. from Furcifer pardalis are cylindrical to ellipsoidal, 27.7 (26-29.5) x 18.4 (17-19) microm, with ellipsoidal sporocysts, 7.3 (6.5-8) x 5.2 (5-5.5) microm. E. vencesi n. sp. described from F. pardalis has spherical to subspherical oöcysts, 14.3 (13-15.5) x 13.0 (12-13) microm, with small granules, one to three globular polar granules and ellipsoidal sporocysts, 7.3 (6.5-8) x 5.2 (5-5.5) microm. E. worthi n. sp., described from Furcifer oustaleti has spherical oöcysts, 17.9 (17.5-19.0) x 15.0 (14.5-16.0) microm without a polar granule and ellipsoidal to cylindroidal sporocysts, 8.2 (7.0-9.5) x 5.8 (5.0-6.5) microm. Oöcysts of E. brookesiae n. sp. from Brookesia decaryi are cylindrical, 25.6 (23-27) x 15.0 (13-16) microm with ellipsoidal sporocysts, 10.1 (9-11) x 6.9 (6-7) microm. Endogenous development of E. vencesi is confined to the intestine, while that of E. glawi occurs in the gall-bladder.

PCR-based differentiation of three porcine Eimeria species and Isospora suis

Isospora suis and Eimeria are frequent coccidian parasites of pigs. The unsporulated oocysts of Eimeria species and of I. suis are difficult to differentiate. Therefore, a species-specific PCR was developed. PCR products were amplified from Eimeria polita, Eimeria porci, and Eimeria scabra using primers from the conserved 18S rRNA regions and were subsequently sequenced. Based on variable sequence regions, primers were constructed for the differentiation of the three Eimeria species and I. suis. Using a combination of PCRs detecting one or two species, all four coccidian species were detected (theoretical lower detection level: DNA content of 250 oocysts of each Eimeria species or 25 oocysts of Isospora in 1microl) and differentiated. The PCR-based differentiation of the above mentioned species provides a useful alternative to microscopy.

Isospora lutrae n. sp. (Apicomplexa: Eimeriidae), a new coccidium from the European otter Lutra lutra (L.) (Carnivora: Mustelidae) from Spain

Parasitological examination of European otter originating from Extremadura, Spain revealed the presence of a new isosporan species. Oöcysts of Isospora lutrae n. sp. are spherical to subspherical, 31.2 (27.5-32) x 29.6 (28-31) microm and have a smooth wall c. 1 microm thick. Sporocysts are ellipsoidal, 18.2 (17-19) x 14.4 (14-16) microm and lack Stieda and substieda bodies. A spherical sporocyst residuum is present, consisting of granules scattered among the sporozoites. Sporozoites are spindle-shaped, 12.4 x 2.5 microm and have anterior and posterior refractile bodies. Based on its unique morphologic structure and host, I. lutrae is considered to be new.

Detection of Isospora belli by polymerase chain reaction using primers based on small-subunit ribosomal RNA sequences

The aim of the present study was to use small-subunit (SSU)-rRNA sequences of Isospora belli to design specific primer pairs and a hybridization probe for the detection of Isospora belli in human samples by PCR and Southern blot hybridization. PCR amplification with the primer pairs produced correct DNA fragments with target DNA from samples of Isospora belli-infected patients and from cloned SSU-rRNA of Isospora belli. The nature of the PCR products was confirmed by Southern blot hybridization. No amplification was seen with template DNA extracted from other parasites. Although Isospora belli infections can be easily diagnosed using light microscopy, molecular-based techniques may prove useful as an additional diagnostic tool.

Parasites of Chaffinch (Fringilla coelebs) population. Part I. Coccidia (Protozoa, Apicomplexa)

Coccidia infection in Chaffinch population in Mazurian Lakeland was studied. Birds were caught in mist nets from June to September and droppings were collected after defecation. Prevalence of infection was high -80% of Chaffinches excreted oocysts of Isospora sp. Intensity of oocysts' production varied depending on the time of the day and therefore coccidia prevalence in Chaffinch should be best detectable in birds caught after midday.

Uvitex 2B stain for the diagnosis of Isospora belli infections in patients with the acquired immunodeficiency syndrome

OBJECTIVE

Fluorescent stains with Uvitex 2B or other fluorochromes are widely used today, especially for the diagnosis of microsporidian infections in human immunodeficiency virus (HIV)-infected patients. Our objective was to ascertain whether the fluorescent stain with Uvitex 2B is also able to detect Isospora belli in stool samples and duodenal/bile juice of HIV-infected patients.

DESIGN

Case study.

SETTING

University hospital of the University of Cologne, Germany.

PATIENTS

Two HIV-infected patients with chronic diarrhea who had intestinal infections with I. belli.

METHODS

Stool was concentrated by a modified water-ether sedimentation method, and duodenal/bile juice was concentrated by centrifugation. Wet-mount preparations were examined by phase-contrast and bright-field microscopy, and smears were stained with a modified acid-fast stain and a fluorescent stain with Uvitex 2B.

RESULTS

Using the fluorescent stain with Uvitex 2B, the oocysts of I. belli stained bright white/blue fluorescent and showed a structure similar to that of the oocysts in acidfast stains.

CONCLUSIONS

Staining with Uvitex 2B is a suitable method for the diagnosis of I. belli infections. This technique can be used for the diagnosis of three important gastrointestinal parasites (viz, microsporidia, cryptosporidia, and I. belli) responsible for diarrhea in HIV-infected patients.