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B Gottstein

Publications and source records attributed to B Gottstein.

At least 19 recordsLinked to original sources
PubMed1992

A large focus of alveolar echinococcosis in central China.

Human alveolar echinococcosis (AE) is a rare and highly pathogenic helminthic zoonosis due to infection with the intermediate stage of the small fox tapeworm, Echinococcus multilocularis. Parasite transmission is restricted to northern latitudes, including central and north China, from where few clinical and no detailed community studies have been reported. In August, 1991, 65 (5%) of 1312 people residing in three rural communes of Zhang County, Gansu Province, China were diagnosed as having hepatic AE after mass ultrasound scanning with serological back-up. This represents one of the highest prevalence rates of AE ever recorded. It is also the first time that mass ultrasound scanning and serology have been used together in an AE endemic region. The region was selected one year earlier, when a preliminary serosurvey on 606 unselected people in the same locality resulted in an 8.8% serum antibody positive rate with a 76% rate of confirmation of hepatic AE in 37 individuals who could be followed up in 1991. Seropositivity rates varied for villages between 0 and 20.5%. Overall, females (7.8%) had a significantly greater risk of infection than males (2.5%), especially in the 31-50 age group, a difference which may be related to contact with dogs and dog faeces over many years. Age-specific prevalence of AE increased from 0% in the under 5-year group to 8.2% in those aged 31-50. The youngest case was 11 years and the mean age of diagnosis was 40 years. Adult tapeworms of E multilocularis were identified from the small intestines of 10% of domestic dogs. Sylvatic animal hosts of the parasite have not yet been identified. The high prevalence of human AE in this region of central China is most probably due to semi-domestic transmission of E multilocularis between wild rodents and dogs, together with the poverty and poor hygiene in these rural communities.

Adolescent↗
PubMed1992

Echinococcus multilocularis: immunological study on the "Em2-positive" laminated layer during in vitro and in vivo post-oncospheral and larval development.

Echinococcus multilocularis oncospheres, primary vesicular cysts, and protoscolices were assessed in vitro and in vivo for their potential to synthesize a PAS-positive laminated layer containing monoclonal antibody (mAb) G11-binding Em2 antigen. The presence of Em2 antigen in developed oncospheres and cysts was subsequently correlated to the potential of in vivo development into a secondary metacestode in recipient host mice, which also responded by anti-Em2 serum antibody formation. In contrast, protoscolices failed to develop the "Em2-positive" layer in vitro under the selected experimental conditions. The failure to develop subsequently in vivo into a secondary metacestode was underlined by a lack of anti-Em2 serum antibody formation by the hosts. We furthermore developed a technique to obtain E. multilocularis clones by inoculating single oncospheres into recipient mice.

Animals↗
PubMed1992

Detection of Echinococcus coproantigens by enzyme-linked immunosorbent assay in dogs, dingoes and foxes.

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of Echinococcus coproantigens in fecal samples from dogs, dingoes or foxes infected with either E. granulosus or E. multilocularis. The ELISA was based on protein-A-purified polyclonal antibodies [anti-E. granulosus excretory/secretory (E/S) antigens]. The specificity of the assay as determined in 155 samples derived from carnivores that were free of helminth infection (n = 37) or infected with non-Echinococcus cestodes (n = 76) or with various nematodes (n = 42) was found to be 98% overall. The diagnostic sensitivity was strongly dependent on the homologous worm burden. All 13 samples from foxes harboring greater than 1,000 E. multilocularis worms and 13 of 15 (87%) samples from dogs or dingoes containing greater than 200 E. granulosus worms were ELISA-positive, whereas 34 of 46 samples from foxes harboring less than 1,000 E. multilocularis and 9 of 10 samples from dogs or dingoes bearing less than 200 E. granulosus tested negative. Experimental prepatent infections of dogs with E. granulosus revealed positive ELISA reactions within the prepatent period (10-20 days post-infection) for six animals bearing greater than 1,000 E. granulosus each; a low worm burden (less than 1,000 tapeworms/animal) resulted in ELISA positivity in only 2 of 3 animals at 30 days post-infection at the earliest. All five dogs that had been experimentally infected with E. multilocularis tested positive in the coproantigen ELISA as early as on day 5 post-infection.

Animals↗
PubMed1992

Molecular and immunological diagnosis of echinococcosis.

Echinococcosis is an infectious disease of humans caused by the larval (metacestode) stage of the cestode species Echinococcus granulosus (cystic echinococcosis or hydatid disease) or Echinococcus multilocularis (alveolar echinococcosis or alveolar hydatid disease). Clinical manifestations depend primarily on localization and size of hepatic lesions and may include hepatomegaly, obstructive jaundice, or cholangitis. Prognostically, alveolar echinococcosis is considered similar to liver malignancies, including a lethality rate of 90% for untreated cases. Diagnosis is based on imaging techniques coupled with immunodiagnostic procedures. Antibody detection tests for E. multilocularis have markedly improved with the use of affinity-purified Em2 antigen and recombinant antigen II/3-10 in enzyme immunoassays. Antigens of corresponding quality for E. granulosus are still unavailable. The detection of circulating antigens and immune complexes in the sera of patients with cystic echinococcosis, the demonstration of in vitro lymphocyte proliferation in response to stimulation with Echinococcus antigens, and the discrimination of serum immunoglobulin isotype activity to various Echinococcus antigens in both cystic and alveolar echinococcosis have been suggested for diagnostic purposes as well as for monitoring patients after treatment. New diagnostic molecular tools include DNA probes for Southern hybridization tests and polymerase chain reaction for the amplification of E. multilocularis and E. granulosus species-specific DNA fragments.

Animals↗
PubMed1992

Parasitological and serological studies on the prevalence of Echinococcus multilocularis Leuckart, 1863 in red foxes (Vulpes vulpes Linnaeus, 1758) in Switzerland.

In the Canton of Zurich in Switzerland, 1,252 red foxes (Vulpes vulpes) were examined during 1990-1991 for intestinal stages of Echinococcus multilocularis using the mucosal smear technique. Special safety precautions were employed during examination. An average of 35% (432 foxes) were infected, mostly with low to medium numbers of gravid worms producing thick-shelled eggs. In the eleven districts of the Canton, prevalence rates varied between 13% and 57%. An average of 29% of the foxes had antibodies in serum or body fluid against a highly species-specific antigen of E. multilocularis (Em2-antigen). The fact that foxes with intestinal E. multilocularis infection have been found in all parts of the Canton of Zurich indicates a relatively high potential infection risk for humans, but apparently the risk is reduced by certain extrinsic or intrinsic factors which have yet to be determined.

Age Factors↗
PubMed1991

Sequencing and characterization of an Echinococcus multilocularis DNA probe and its use in the polymerase chain reaction.

The nucleotide sequence of the cloned Echinococcus multilocularis DNA probe pAL1 was determined in order to simplify and improve the sensitivity of a diagnostic assay through the application of the polymerase chain reaction (PCR). The insert-specific oligonucleotides BG1 and BG2 define a 2.6-kb fragment in the genomic DNA of E. multilocularis, while BG1 and BG3 define a 0.3 kb fragment. A PCR study including 14 independent E. multilocularis isolates in addition to Echinococcus granulosus. Echinococcus vogeli, Taenia spp. and other cestodes revealed that the 2.6-kb fragment was amplified from genomic DNA of all E. multilocularis isolates tested (originating from Switzerland, Alaska, Canada, France, Germany and Japan), but from genomic DNA of none of the other cestode species. PCR with BG1 and BG2 furthermore uniquely resulted in the synthesis of a 0.55-kb fragment specific for Taenia saginata and a 0.6-kb fragment specific for T. taeniaeformis. In contrast to the species specificity of the 2.6-kb BG1/BG2 product, the 0.3 kb (BG1/BG3) product demonstrated genus specificity: the 0.3-kb product was amplified from genomic DNA of all E. multilocularis, E. granulosus and E. vogeli isolates tested, but from genomic DNA of none of the other cestode species. The diagnostic sensitivity of PCR using both primer sets was determined to be 50 pg parasite DNA, suggesting the practical utility of this simple assay in demonstrating parasite DNA in specimens from a variety of sources. At the basic level, the pAL1-derived oligonucleotides may also prove useful in assessing strain variation, RFLPs or other manifestations of genetic variation in E. multilocularis.

Animals↗
PubMed1991

A monoclonal antibody against Echinococcus multilocularis Em2 antigen.

A monoclonal antibody (MAb G11) species-specific to the Em2 antigen of Echinococcus multilocularis was generated for (i) further biological characterization of the Em2 antigen, (ii) easy affinity-purification of Em2 antigen for immunodiagnostic and immunological investigations and (iii) development of a sandwich-ELISA for the detection of Em2 antigen in diagnostic samples and thus species-specific identification of E. multilocularis metacestode material. The MAb G11 was used in an antibody sandwich-ELISA to detect soluble Em2 antigen with a methodical sensitivity of 80 ng E. multilocularis antigen/ml of solution. MAb G11 specifically detected Em2 antigen in all of 15 E. multilocularis-isolates originating from various geographical areas and in none of other helminth isolates (e.g. Echinococcus granulosus, E. vogeli, and others). Further biological analysis by FITC-labelled MAb G11 demonstrated unique binding activity to the laminated layer of the metacestode. Also, oncospheres were binding FITC-labelled MAb G11 on an outer layer synthesized during cultivation in vitro for 13 days after hatching. Application of the MAb G11 antibody sandwich-ELISA for investigation of solubilized oncospheres confirmed the in vitro synthesis of Em2 antigen by oncospheres on day 13 p.i. Adult stages (somatic antigens) and freshly hatched oncospheres were always MAb G11 negative. Solid-phase MAb G11 was used for purification of the corresponding Em2 antigen by affinity chromatography. A preliminary serological evaluation of the Em2(G11) antigen by ELISA revealed identical immunodiagnostic characteristics, compared to Em2 obtained by classical means, thus suggesting the presented method for future isolation of large-scale Em2 antigen.

Animals↗
PubMed1991

Antigenic variation in Giardia lamblia: infection of congenitally athymic nude and scid mice.

Athymic nude mice of the outbred Zur:ICR-nu and inbred BALB/c strain and scid mice were infected with a cloned human isolate of Giardia lamblia (GS/M-83-H7). Changes in the expression of the major surface epitope of the intestinal trophozoites (characterized by the binding capacity of monoclonal antibody MoAbG10/4) as well as cellular and humoral immune parameters of the hosts were followed during the course of infection. Self-cure was observed in heterozygous (nu/+) BALB/c mice by day 22 post-infection (p.i.) and in heterozygous (nu/+) Zur:ICR-nu strain by day 65 p.i. Homozygous (nu/nu) mice of both strains remained chronically infected until end of the experiments (day 45 p.i. for BALB/c mice and day 122 p.i. for Zur:ICR-nu mice, respectively). Only heterozygous (nu/+) mice were able to mount a gut-associated (Peyer's patch) lymphoproliferative response to G. lamblia antigen. Therefore, T-cell dependent mechanisms were necessary for a self-cure. Antigenic variation occurred in all nu/+ and nu/nu animals of both strains. Trophozoites expressing the major surface epitope (assessed by direct immunofluorescence with FITC-labelled MoAb G10/4) decreased to zero by day 22 p.i. In contrast, the proportion of trophozoites expressing the major surface epitope in infected scid mice remained at the initial level (greater than 99%) until termination of the experiment (day 25 p.i.); therefore, antigenic variation did not occur. All nu/nu and nu/+ mice but not scid mice demonstrated a humoral immune response to G. lamblia antigen. These experiments suggest functional B-cell dependent mechanisms are most likely responsible for the surface antigen switch. Transfer of infection occurred naturally from experimentally infected scid-mice to their mother, proving the initial antigenic surface variant remains unchanged after encystment and subsequent excystment followed by infection in a new host.

Animals↗
PubMed1991

Serological (Em2-ELISA) and parasitological examinations of fox populations for Echinococcus multilocularis infections.

Serum or body fluid samples of 1,006 foxes were investigated in an ELISA for antibodies against a highly sensitive and specific antigen (Em2-antigen) of Echinococcus multilocularis. Parasitological examinations of the intestines and simultaneous serological examinations were carried out in 505 foxes: A group of 98 blue foxes (Alopex lagopus) from Norwegian fox farms did not contain intestinal stages of E. multilocularis and was clearly sero-negative in Em2-ELISA. On the other hand in red foxes (Vulpes vulpes) originating from European areas known to be endemic for E. multilocularis the following average prevalence rates were found: 244 foxes from Southern Germany, E. multilocularis prevalence 55% and sero-prevalence 60%; 139 foxes from Austria, E. multilocularis prevalence 4% and sero-prevalence 12%. Serological identification of individual foxes with or without intestinal E. multilocularis infection was not possible. Only serological (no parasitological) examination in 402 foxes originating from endemic areas in Switzerland resulted in a sero-prevalence rate of 37%. Sero-prevalence was only 6% and 4% in 54 and 26 other foxes, respectively, originating from Swiss and German areas where E. multilocularis has not yet been reported. Negative control Norwegian (farmed) silver foxes (n = 43) were all sero-negative. The specificity of the Em2-ELISA was confirmed by negative Em2-serologies with sera from dogs infected with intestinal and tissue dwelling helminth species (with the exception of two from 24 dogs infected with E. granulosus).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Immunodiagnosis of toxocarosis in humans: evaluation of a new enzyme-linked immunosorbent assay kit.

Excretory/secretory (E/S) antigen derived from second-stage larvae of Toxocara canis maintained in defined medium in vitro has been well established worldwide for the immunodiagnosis of human toxocarosis by enzyme-linked immunosorbent assay. Such an enzyme-linked immunosorbent assay, based on the detection of human anti-T. canis (E/S antigen) serum immunoglobulin G, has recently been commercialized by Biokema-Affinity Products (Crissier-Lausanne, Switzerland). This commercial test kit was evaluated with regard to its application in a routine diagnostic laboratory and the reliability of the results. Of 78 patients with suspected clinical toxocarosis, 71 had anti-T. canis antibodies (positive serological result) corresponding to a diagnostic sensitivity of 91%; 14% of serum samples (n = 199) from patients with protozoan or with helminthic infections also showed positive reactions mainly related to infections with Trichinella, Strongyloides, and Fasciola species. An epidemiological study with 1,000 serum samples from randomly selected healthy blood donors and children in Switzerland demonstrated a seroprevalence of 2.7%. The test kit under evaluation had an overall diagnostic sensitivity of 91% and a relative specificity of 86%, the latter being related to some protozoan and helminthic infections. Because of the scarcity of such infections, potential cross-reactivity does not play a major role under the conditions found in the middle part of Europe. In conclusion, the application of the test kit provided for use in this study can be recommended for routine diagnostic use.

Animals↗
PubMed1991

Specific cellular and humoral immune responses in patients with different long-term courses of alveolar echinococcosis (infection with Echinococcus multilocularis).

Alveolar echinococcosis is a serious and often fatal disease of humans that in most cases can be efficiently cured only by complete surgical resection of the Echinococcus multilocularis lesion. In a few patients, however, a spontaneous cure of the disease has been observed by demonstrating the presence of lesions with dead metacestodes. The present study shows a comparative analysis of the cellular (lymphoproliferative assay) and humoral (antibody activity in an Em2 enzyme-linked immunosorbent assay [ELISA] and immunoblotting) immune response in 1) patients who were cured by a radical surgical resection of the E. multilocularis parasite lesion, 2) patients who had a partial surgical resection of the parasite lesion, 3) patients who had a non-resectable alveolar echinococcosis, and 4) patients who were shown to be spontaneously cured and had lesions with dead parasites. The in vitro lymphoproliferative response to E. multilocularis antigen stimulation was very high in cured patients who had radical surgery or in patients with lesions containing dead parasites, but it was significantly lower in patients who had partial surgical or no resection. Antibody concentrations in the Em2-ELISA were high in patients who had incomplete or no surgery, and low or negative in cured patients who had radical surgery or in patients with lesions containing dead parasites. Immunoblot analysis of patient sera revealed a consistent antibody banding pattern among cured patients with radical surgery and patients with incomplete or no surgery, whereas cured patients with lesions containing dead parasites showed a very faint antibody pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Parasitologic, clinical, hematologic and serologic findings in puppies after lactogenic infection with Ancylostoma caninum ERCOLANI 1859 (Ancylostomidae)].

The correlation between intensity of Ancylostoma caninum infections in bitches and the intensity of lactogenic infections and clinical signs of their puppies was investigated. On average, 825, 1,867 or 2,125 specimens were observed in litters of two bitches inoculated with 5,000, 10,000 or 20,000 third stage larvae (LIII) respectively, at the day of conception. Adverse effects of the infection on the growth and behaviour of the puppies were observed after onset of their second week of life: 11/27 puppies died during the fourth week. The body weight of puppies surviving 28 days was up to 750 g less than that of uninfected controls. Eosinophilia, erythroblastosis and microcytic, hypochromic anemia developed in all puppies during their first four weeks. The IFA test (LIII antigen) was positive for only 5/18 heavily infected puppies after uptake of colostrum.

Ancylostoma↗
PubMed1990

Echinococcus multilocularis: characterization of a DNA probe.

A 0.6 kb DNA fragment has been isolated from a genomic sublibrary of the cestode Echinococcus multilocularis. This DNA-fragment showed a strong hybridization signal to 32PdCTP labeled total DNA prepared from E. multilocularis metacestode material. The fragment was subcloned into the Escherichia coli vector Bluescript BS+ resulting in the recombinant plasmid pAL1. The recombinant parasite DNA probe was labeled by biotinylation and hybridized to Southern blots of resolved EcoRI/PstI digested genomic DNA originating from E. multilocularis, E. granulosus and other helminth species (Taenia hydatigena, T. crassiceps, T. saginata, Mesocestoides corti, Hymenolepis diminuta, Moniezia expansa). The Southern blot hybridization experiments revealed that the DNA probe pAL1 was specific for E. multilocularis and E. granulosus. By comparison of the hybridization banding patterns a clear discrimination between E. multilocularis and E. granulosus was possible at the genome level. Furthermore, pAL1 was used to detect genetic variation within a set of different E. multilocularis isolates which had been experimentally maintained in mice by parasite tissue transplantation.

Animals↗
PubMed1990

Serological survey of human cysticercosis in Irianese refugee camps in Papua New Guinea.

In 1984, over 10,000 refugees left the Indonesian province of Irian Jaya, and thus possibly imported Taenia solium taeniasis/cysticercosis into Papua New Guinea, which was believed to be free of T. solium until 1966. In a serological survey carried out in 1986, 50 refugees originating from areas endemic for T. solium and 171 patients from other areas with symptoms suggesting the possibility of cysticercosis were examined. As a sensitive prescreening technique an ELISA was used with a crude antigen extract obtained from T. solium metacestodes of pig origin. Of 221 persons investigated, 79 (36%) were positive in ELISA. For excluding frequently occurring cross-reactions in ELISA, Western-blotting (or EITB, enzyme-linked immunoelectrotransfer blot) was employed. In this test the demonstration of antibody activity to the 26 or the 8 kilodalton band has been proved to be species-specific for T. solium cysticercosis. One from 79 patients positive in ELISA was simultaneously positive (26 and 8 kDa) in Western blot, corresponding to the first case found in Papua New Guinea with a highly probable T. solium cysticercosis. This patient, originating from an endemic area in Irian Jaya, had immigrated into Papua New Guinea in 1980. The present work emphasizes the need for using highly specific immunodiagnostic techniques in seroepidemiology of larval cestode infections. T. solium taeniasis/cysticercosis remains a risk for Papua New Guinea, and refugees originating from endemic areas should be regarded as potential carriers of T. solium.

Animals↗
PubMed1990

Detection of Taenia hydatigena copro-antigens by ELISA in dogs.

A sandwich-ELISA was developed for the detection of soluble Taenia hydatigena antigens in fecal samples of dogs. Affinity-purified polyclonal catching antibodies and alkaline phosphatase-conjugated detecting antibodies were employed, which had been obtained from rabbits hyperimmunized with excretory/secretory antigens derived from in vitro maintained adult Taenia hydatigena. The assay allowed the detection of 800 ng T. hydatigena antigen g-1 of feces as a lower limit. Six helminth-free dogs were each infected with 10 T. hydatigena cysticerci isolated from Swiss sheep. After prepatent periods ranging from 57 to 71 days, the dogs started to excrete Taenia eggs and/or proglottids. The ELISA detected Taenia antigens in all six dogs during the prepatent period starting individually between Day 18 and 45 post-infection (p.i.). Anthelmintic treatment of three dogs at Day 95 p.i. resulted in elimination of the cestodes and within the 5 following days in the disappearance of Taenia antigens from feces. The specificity of the assay was evaluated by testing crude antigens derived from helminths or bacteria. Four Taenia species showed cross-reactivity at concentrations of 5 micrograms protein ml-1. Conversely, no cross-reactions occurred with various antigen batches derived from Echinococcus granulosus, E. multilocularis, Dipylidium caninum, Mesocestoides corti, Diphyllobothrium sp., Toxocara canis and bacterial antigens (Salmonella and Escherichia). Moreover, fecal samples from dogs naturally infected with T. canis (n: 13), hookworms (n: 2), Trichuris vulpis (n: 13) and of 10 dogs with mixed infections with these three nematode groups were tested, and results confirmed the high degree of specificity. The Taenia antigens detectable by this ELISA remained immunologically stable in native feces stored at +25 degrees, +4 degrees or at -20 degrees C for at least 5 days.

Animals↗