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PubMedDate not supplied

Specificity and sensitivity of a rapid dipstick test (Brugia Rapid) in the detection of Brugia malayi infection.

A total of 753 serum samples from 6 institutions in 3 countries (Malaysia, Indonesia and India) were used to evaluate an immunochromatographic rapid dipstick test, Brugia Rapid, for diagnosis of Brugia malayi infection. The samples comprised sera from 207 microfilaria-positive individuals and 546 individuals from filaria non-endemic areas. The latter consisted of 70 individuals with soil-transmitted helminth infections, 68 with other helminth infections, 238 with protozoan infections, 12 with bacterial and viral infections and 158 healthy individuals. The dipstick is prepared with a goat anti-mouse antibody control line and a B. malayi recombinant-antigen test line. First, the dipstick is dipped into a well containing diluted patient serum, thus allowing specific anti-filarial antibody in the serum to react with the recombinant antigen. Then the dipstick is placed into an adjacent well containing reconstituted anti-human IgG4-gold. After 10 min, development of 2 red-purplish lines denotes a positive result and one line indicates a negative reaction. The overall results of the evaluation showed 97% sensitivity, 99% specificity, 97% positive predictive value and 99% negative predictive value. Brugia Rapid is thus a promising diagnostic tool for detection of B. malayi infection, and would be especially useful for the brugian filariasis elimination programme.

Animals↗
PubMed2007

Current therapeutics, their problems, and sulfur-containing-amino-acid metabolism as a novel target against infections by "amitochondriate" protozoan parasites.

The "amitochondriate" protozoan parasites of humans Entamoeba histolytica, Giardia intestinalis, and Trichomonas vaginalis share many biochemical features, e.g., energy and amino acid metabolism, a spectrum of drugs for their treatment, and the occurrence of drug resistance. These parasites possess metabolic pathways that are divergent from those of their mammalian hosts and are often considered to be good targets for drug development. Sulfur-containing-amino-acid metabolism represents one such divergent metabolic pathway, namely, the cysteine biosynthetic pathway and methionine gamma-lyase-mediated catabolism of sulfur-containing amino acids, which are present in T. vaginalis and E. histolytica but absent in G. intestinalis. These pathways are potentially exploitable for development of drugs against amoebiasis and trichomoniasis. For instance, L-trifluoromethionine, which is catalyzed by methionine gamma-lyase and produces a toxic product, is effective against T. vaginalis and E. histolytica parasites in vitro and in vivo and may represent a good lead compound. In this review, we summarize the biology of these microaerophilic parasites, their clinical manifestation and epidemiology of disease, chemotherapeutics, the modes of action of representative drugs, and problems related to these drugs, including drug resistance. We further discuss our approach to exploit unique sulfur-containing-amino-acid metabolism, focusing on development of drugs against E. histolytica.

Amino Acids, Sulfur↗
PubMed2006

Prevalence of cryptosporidium and other enteric parasites among wild non-human primates in Polonnaruwa, Sri Lanka.

Cryptosporidiosis is a rapidly emerging disease in the tropics. This is the first report of Cryptosporidium and other protozoan infections (Entamoeba spp., Iodamoeba, Chilomastix, and Balantidium spp.) in wild primates that inhabit the natural forest of Sri Lanka. It is unclear if non-human primates serve as a reservoir for these parasites under certain conditions. A cross-sectional coprologic survey among 125 monkeys (89 toque macaques, 21 gray langurs, and 15 purple-faced langurs) indicated that Cryptosporidium was detected in all three primate species and was most common among monkeys using areas and water that had been heavily soiled by human feces and livestock. Most macaques (96%) shedding Cryptosporidium oocysts were co-infected with other protozoans and important anthropozoonotic gastrointestinal parasites (e.g., Enterobius and Strongyloides). The transmission of these parasites among primates in the wild may have important implications for public health as well as wildlife conservation management.

Animals↗
PubMed1981

Intestinal parasitism in an outdoor breeding colony of Macaca mulatta.

A portion of a large outdoor breeding colony of rhesus monkeys (Macaca mulatta) was surveyed for intestinal parasites. The results of this examination were compared to data obtained at the time of arrival for this same group of animals. In addition, a small number of infants born in the colony were examined. Although most species of parasites detected during quarantine were retained in the breeding colony, the parasite population changed. The number of helminthic infections doubled while protozoan infections decreased by 20%. Trichuris (47%), Strongyloides (34%), Entamoeba (59%), Endolimax (20%), and Iodamoeba (20%) were the most common parasites detected in the outdoor breeding colony.

Animal Husbandry↗
PubMed1999

IL-10 gene knockout mice show enhanced Th1-like protective immunity and absent granuloma formation following Chlamydia trachomatis lung infection.

We previously reported that higher IL-10 production is correlated with lower IFN-gamma production, weaker delayed hypersensitivity (DTH), and slower organism clearance following chlamydial infection in mice. To assess more directly the role of IL-10, we examined protective immunity and pathological reaction in C57BL/6 IL-10 gene knockout (KO) and wild-type mice. The results showed that in the absence of endogenous IL-10, mice had significantly accelerated chlamydial clearance and developed significantly stronger DTH responses, which could be inhibited by local delivery of rIL-10. Consistent with the enhancement of DTH responses, IL-10 KO mice showed stronger and more persistent CD4 T cell-dependent IFN-gamma production and significant elevation of IL-12 and TNF-alpha production. Additionally, wild-type, but not IL-10 KO, mice showed granuloma formation that was correlated with higher levels of Th2 cytokine (IL-5) production at the later stages of infection. Moreover, chlamydial infection, unlike parasitic protozoan infection, did not induce significant acute toxicity in IL-10 KO mice, which may be due to the low (undetectable) levels of systemic release of proinflammatory cytokines. These results suggest that IL-10 inhibits the priming and expansion of Th1-like T cell responses and that IL-10 plays a role in the fibrotic reaction seen with chlamydial infection.

Animals↗
PubMed2001

Protozoan enteric infection in AIDS related diarrhea in Thailand.

The aim of this study was to determine the prevalence of enteric protozoa and other pathogens in AIDS patients with diarrhea in Bangkok, Thailand. Of 288 consecutive patients screened in the 10 month period between November 1999-August 2000 inclusive, 55 (19.2%) had Cryptosporidium spp, 13 (4.5%) had Isospora oocyst, 11 (3.8%) had Giardia lamblia, 3 (0.9%) had Entamoeba histolytica, and 1 (0.3%) had Iodamoeba butschlii infection. The prevalence of microsporidia was 11% in this study. Of 251 patients for whom stool culture for bacteria was performed, enteric bacterial pathogens isolated were Campylobacter spp in 18 (7.1%), Salmonella spp in 11 (4.3%), and Shigella spp in 1 (0.5%). Other pathogens found in these patients were Clostridium difficile in 16/102 (15.6%). Mycobacterium spp in 18/287 (6.2%), and Strongyloides stercoralis in 23/288 (8.0%). Overall, parasitic and bacterial pathogens were identified in 140 (48.6%) patients. These pathogens were identified by the routine simple wet smear technique in 32, formalin-ether concentration method in 46, culture for S. stercoralis in 5, and culture for bacteria in 30. Additional test, using modified Ziehl-Neelsen staining, identified cryptosporidial oocyst, isospora oocyst, and Mycobacterium spp in 72. The microsporidia, initially identified by modified trichrome blue staining, all were then determined to be Enterocytozoon bieneusi by thin sectioning electron microscopy. Protozoan and bacterial pathogens were confirmed to be important etiologic agents in diarrhea in AIDS in Thailand. They were all associated with increased mortality. Routine stool examination by simple wet smear detected only one-fourth of these pathogens. Therefore all diagnostic techniques for these organisms should be made more widely available in Thailand.

AIDS-Related Opportunistic Infections↗
PubMed1991

Mortality in Atlantic salmon (Salmo salar) associated with trichodinid ciliates.

A protozoan infection (Trichodina truttae) was identified in captive Atlantic salmon (Salmo salar) kelts that died in spring of 1988 and 1989. Fish with intense infections showed signs of listlessness, erratic swimming and inappetence. The infection induced excessive mucus secretion, epithelial sloughing and lesions that probably permitted entry of opportunistic bacteria which eventually caused ulcers and death. A seawater bath for 30 min each week for 4 wk effectively controlled the parasite.

Animals↗
PubMed1982

The prevalence of Dirofilaria immitis and other parasites in urban pound dogs in north-eastern Victoria.

The results of a survey investigating the prevalence of dirofilaria immitis and other helminth and protozoan infections in urban dogs in north-eastern Victoria are presented. D. immitis was detected in 2.7% of the general population (8.3% of dogs older than 2 years). Microfilariae of D. immitis were not detected in the peripheral circulation of 30% of dogs infected with the adult parasites. The most prevalent gastro-intestinal parasites were Dipylidium caninum 57%; Trichuris vulpis 41%; Toxocara canis 38%; and Uncinaria stenocephala 26%. The prevalence of T. canis in dogs less than one year of age was 73% and this decreased with increasing age. No Echinococcus granulosus adults were detected. Sarcocystis spp and isospora ohioensis were the most commonly seen coccidians.

Animals↗
PubMed1981

Vertebrate cell cycle modulates infection by protozoan parasites.

Synchronized HeLa cell populations were exposed to Trypanosoma cruzi or Toxoplasma gondii, obligate intracellular protozoan parasites that cause Chagas' disease and toxoplasmosis, respectively, in humans. The ability of the two parasites to infect HeLa cells increased as the HeLa cells proceeded from the G1 phase to the S phase of their growth cycle and decreased as the cells entered G2-M. Characterization of the S-phase cell surface components responsible for this phenomenon could be beneficial in the development of vaccines against these parasitic diseases.

Animals↗
PubMed1981

Protozoan and viral infections of feral cats.

Identification of protozoan oocysts and serological tests were used to determine the prevalence of infections among 300 mainly adult feral cats in three different habitat types in south-eastern Australia. Oocysts of Isospora rivolta and Isospora felis were recovered from 3% and 4% respectively of 300 feral cat samples. Haemagglutination inhibition antibody to Toxoplasma gondii was detected in 20% of 75 cat sera tested. A high prevalence of specific antibody to feline panleukopaenia virus (79%) and feline calici virus (77%) was demonstrated but the prevalence of antibody to feline herpes virus was low (11%). 15 strains of feline calici virus were isolated from pharyngeal swabs. There were no other virus isolations from the 60 pharyngeal and rectal swabs taken. These viral and protozoan infections could not be linked with any obvious pathological conditions. Most cats were in good condition with light to moderate fat stores in depot areas. Limb fractures and other skeletal abnormalities occurred infrequently. Major tooth damage or absence of important teeth was evident in about 20% of 164 animals examined. There was no correlation between major tooth damage and poor body condition.

Animals↗
PubMed2006

Survey of gastrointestinal parasitic infections in quarantined dogs in Taiwan.

Intestinal helminth and protozoan infection in the quarantined dogs in Taiwan were examined using fecal examination between January to December, 2004. Of the 376 dogs imported from 11 countries, 63 (16.8%) were found to be infected with at least one species of intestinal parasite. The parasites detected were oocysts of Isospora canis and eggs of Toxocara canis, Trichuris vulpis and hookworms. Of the 63 infected dogs, 11 were found to have a mixed infection of two different species of parasites. This paper illustrates that parasites are transmitted from one country to another through the transport of animals. Moreover, there is also a possibility of parasitic infection among quarantined dogs as well as the zoonotic potential for quarantine officers during the quarantine period.

Animals↗
PubMed2003

Breaking the species barrier: use of SCID mouse-human chimeras for the study of human infectious diseases.

Mouse-human chimeras have become a novel way to model the interactions between microbial pathogens and human cells, tissues or organs. Diseases studied with human xenografts in severe combined immunodeficient (SCID) mice include Pseudomonas aeruginosa infection in cystic fibrosis, group A streptococci and impetigo, bacillary and amoebic dysentery, and AIDS. In many cases, disease in the human xenograft appears to accurately reproduce the disease in humans, providing a powerful model for identifying virulence factors, host responses to infection and the effects of specific interventions on disease. In this review, we summarize recent studies that have used mouse-human chimeras to understand the pathophysiology of specific bacterial and protozoan infections.

Animals↗
PubMed1972

[Studies on the incidence of the intestinal protopozoa in the mountainous area of Chollapuk-do]

This study was undertaken in order to elucidate the prevalences of the intestinal protozoan infection according to localities and the mode of the infestation in the mountainous area of Chollapuk-do, Korea during the year 1970-1971. 8,508 of fecal samples were collected among the inhabitants of the mountainous area, which covered 18 Myens(=Township) from 6 Guns(=County) in the eastern part of Chollapuk-do. Most of the inhabitants of this area were engaged in farming and living under lower economic and poor sanitary conditions. The samples were examined twice repeatedly by iodine stained direct fecal smear method. For the study on the mode of infestation, with the exception of drinking water, the zinc sulfate floatation technic was applied for the examinations of hog-feces, manure heap, garden soil, sewage, dishtowel, dust in room and floor, house fly and house rat. The results were summarized as follows: 1. Among total 8,508 fecal specimens examined, 3,152(37.6 %) were positive for the intestinal protozoa: E. histolytica 9.8 %, E. coli 25.6 %, E. nana 7.2 %, G lamblia 6.8 %, I. butschlii 0.6 %, and C. mensnili 0.7 %. 2. A single infection of the intestinal protozoa was the highest(68.3 %), and double infection(22.3 %) triple, quadruple and quintuple infections were in decreasing order. 3. The highest distribution (39.8 %) was observed in the group aging 41-50, and the lowest (27.3 %) in the group above 61. The groups under 10 years showed a relatively high positive rate among all age groups. 4. Sexual distribution of protozoan infection showed slightly higher rate (38.6 %) in male than that (35.4 %) of female. 5. Jangsoo-gun showed the highest positive rate (42.9 %) and Namwon-gun was the lowest (32.5 %). The prevalence of E. histolytica showed the highest (11.6 %) in Imsil-gun and the lowest (6.9 %) in Jangsoo-gun. 6. E. histolytica cysts were found 9.1 % among total 99 samples of hog feces, 4.8 % among 78 samples of manure heap, 0.6 % among 164 samples of fingernail dirt, 5.3 % among 57 samples of drinking water, 15.8 % among 19 samples of sewage, 7.1 % among 42 samples of dishtowel, 0.1 % among 780 samples of house fly and 5.0 % among 40 samples of house rat.

Journal Article↗
PubMed1984

Immunodiagnostic tests for protozoan and helminthic infections.

Immunodiagnostic tests for human protozoan and helminthic infections are reviewed. The need for immunodiagnostic tests varies with each infection but is of paramount importance in those infections that cannot be parasitologically diagnosed readily such as toxoplasmosis, pneumocystosis, Chagas' disease, trichinosis, hydatidosis, cysticercosis, and visceral larva migrans. Immunoassays are also needed for those worldwide highly prevalent infections with severe morbidity to be used in seroepidemiology and in the follow-up evaluation of control programs. The most important are malaria, schistosomiasis, onchocerciasis, lymphatic filariasis, and trypanosomiasis. Major advances have been made in the use of enzyme-linked immunosorbent assay (ELISA) as a practical and rapid test for use in endemic countries and in the identification and isolation of diagnostic parasite antigens aided in particular by the use of monoclonal antibodies. Development of immunodiagnostic tests for specific parasite antigens in body fluids for many infections is being actively pursued.

Amebiasis↗
PubMed1996

[Diagnostic PCR in veterinary parasitology: tritrichomonosis, neosporosis/toxoplasmosis echinococcosis/cysticercosis].

The PCR is now widely introduced as a diagnostic and epidemiological tool in veterinary and human parasitology. Certain parasitic infections are detected using PCR with much higher sensitivity compared to conventional methods, and novel molecular approaches are considered for the analysis of infectiological questions. A broad spectrum of parasites relevant for veterinary and human parasitology already can be diagnosed by PCR. In the present review article, PCR-based methods developped or applied at the Institute of Parasitology in Berne for the detection of protozoan infections (Tritrichomonosis, Neosporosis, Toxoplasmosis) and helminthic infections (Echinococcosis, Taeniosis) are summarized.

Animals↗
PubMed1994

Scientific hypothesis: a new strategy for the design of anti-protozoal drugs--DNA polymerase as a drug target.

Chemotherapy against protozoan diseases has been practised since ancient times. Although still widely used, antiparasitic drugs are seldom completely effective. Complete elimination of an extensive protozoan infection usually requires a combination of drugs which target parasitic mechanisms very similar to the human host, as manifested by a multitude of side effects of varying severity. Furthermore, there is an escalating problem of widespread resistance to commonly used chemotherapeutic agents. Here we present an alternative strategy for the design of antiprotozoal agents using the principal enzyme involved in DNA replication as a possible drug target--DNA polymerase.

Animals↗