Secretory immunoglobulin A antibodies to the galactose-inhibitable adherence protein in the saliva of patients with amebic liver disease.

Monoclonal antibodies directed against the 260-kD galactose-inhibitable adherence protein (GIAP) of Entamoeba histolytica inhibit binding of amebic trophozoites to purified colonic mucins, suggesting that anti-GIAP secretory immunoglobulin A (sIgA) may have a role in host defense in invasive amebiasis. We determined by enzyme-linked immunosorbent assay (ELISA) whether a salivary anti-GIAP sIgA response was present in patients from the Republic of South Africa with invasive E. histolytica infection.

Invasive amoebiasis is associated with the development of anti-neutrophil cytoplasmic antibody.

Features of tissue damage in invasive amoebiasis, in particular polymorphonuclear neutrophil (PMN) degranulation and vasculitis, bear resemblance to that seen in Wegener's granulomatosis, the latter being associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA). We therefore tested sera from patients with confirmed amoebic liver abscess (ALA) for the presence of ANCA by means of an indirect fluorescent antibody test using pure neutrophils as substrate. ANCA was detected in 97.

Control of an amoebiasis outbreak in the Philippi area near Cape Town.

Previous studies in Durban have shown that serological investigations, in combination with iso-enzyme electrophoresis, are invaluable for monitoring the endemicity of pathogenic strains of Entamoeba histolytica. We therefore proposed that antibody profiles could be used to detect epidemic situations. An outbreak of amoebiasis in the normally non-endemic Philippi area near Cape Town provided an opportunity for testing this hypothesis.

Differentiation of pathogenic Entamoeba histolytica infections from nonpathogenic infections by detection of galactose-inhibitable adherence protein antigen in sera and feces.

We determined whether epitope-specific monoclonal antibodies to the galactose-inhibitable adherence protein (GIAP) of Entamoeba histolytica could be used in an enzyme-linked immunosorbent assay (ELISA) to detect antigen in serum and feces and differentiate between nonpathogenic zymodemes and the potentially invasive pathogenic organisms that require treatment. Overall, 57% of subjects from Cairo, Egypt, with symptomatic intestinal amebiasis and 42% with asymptomatic infection possessed GIAP antigen in their sera, whereas 4% of uninfected controls or subjects with other parasitic infections possessed GIAP antigen in their sera (P < 0.001).

Pancytopaenia associated with disseminated tuberculosis, reactive histiocytic haemophagocytic syndrome and tuberculous hypersplenism.

A 38-year-old black male is reported with a rare combination of disseminated tuberculosis together with a reactive histiocytic haemophagocytic syndrome and tuberculosis hypersplenism. Tuberculosis and histiocytic haemophagocytosis were diagnosed on bone marrow examination. The pancytopaenia and splenomegaly which were present on admission did not resolve despite adequate anti-tuberculosis chemotherapy.

Morbidity from falciparum malaria in Natal/KwaZulu.

Plasmodium falciparum malaria is endemic in the northern KwaZulu areas of South Africa. The clinical morbidity produced by this parasite has not been studied since the institution of the present malaria control programme. Fifty-nine patients were prospectively studied at a peripheral clinic during the peak malaria season; symptoms and signs of the infection, parasite loads, haemoglobin values and leucocyte counts were recorded in all patients.

Immunological similarity between the 170 kD amoebic adherence glycoprotein and human beta 2 integrins.

Amoebiasis is an important cause of morbidity and mortality in developing countries. Virulence of Entamoeba histolytica depends on the trophozoite's being able to bind to colonic epithelium; binding is mediated by the 170 kD subunit of a 260 kD lectin. We found, by microcytofluorometry and western blotting studies, that this 170 kD subunit protein shares an epitope with human beta 2 integrins--a subfamily of cell-surface glycoproteins expressed exclusively on leucocytes and involved in many adhesive and signalling interactions.

Use of a recombinant 170-kilodalton surface antigen of Entamoeba histolytica for serodiagnosis of amebiasis and identification of immunodominant domains of the native molecule.

We expressed the gene that encodes one of the major surface antigens of Entamoeba histolytica, the 170-kDa protein (1,270 amino acids), as a glutathione S-transferase fusion protein containing amino acids 1 to 1202 (lacking the putative transmembrane and cytoplasmic regions) and as separate fusion proteins containing each of three major domains of the 170-kDa molecule. Lysates from bacteria induced to express one of these proteins were used as the target antigens in a Western blot (immunoblot) analysis to determine whether a recombinant 170-kDa antigen could serve as the basis for a serologic test used to detect invasive amebiasis and whether there are differences in humoral immunogenicity among the three major domains of the 170-kDa antigen. Among patients with invasive amebiasis from three major areas where the disease is endemic and two sites in the United States, 54 (90%) of 60 had antibodies to the recombinant 170-kDa protein.

An outbreak of multiresistant Salmonella typhi in South Africa.

Typhoid fever caused by Salmonella typhi remains endemic to many parts of South Africa, including Natal and KwaZulu, Northern Transvaal and the Transkei. Until recently, the majority of S. typhi isolates from South Africa have remained susceptible to ampicillin/amoxycillin and chloramphenicol, and only three cases of typhoid due to multi-antibiotic resistant strains of S.

Serodiagnosis of invasive amebiasis using a recombinant Entamoeba histolytica protein.

One hundred eight serum samples from 106 patients were examined by Western blot analysis for the presence of antibodies to a recombinant fusion protein containing the sequence of the newly described serine-rich Entamoeba histolytica protein (SREHP). Among patients with invasive amebiasis from Durban, Republic of South Africa; San Diego, Calif; Mexico City, Mexico; and St Louis, Mo, 53 (82%) of 65 had antibodies to SREHP. In contrast, only one patient (2%) of 43 without acute invasive amebiasis had antibodies to SREHP.

Cryptosporidium infections in children in Durban. Seasonal variation, age distribution and disease status.

One hundred and eleven of 1,229 children (9%) aged less than 10 years admitted to King Edward VIII Hospital, Durban, with gastro-enteritis over a period of 1 year were found to harbour Cryptosporidium. Of these, 96 (89.7%) were less than 2 years of age.

A comparative assessment of commonly employed staining procedures for the diagnosis of cryptosporidiosis.

Following an increase in the number of reports of Cryptosporidium infections and the problems encountered in detecting these organisms in faecal smears, a comparative assessment of a modification of the Sheather's flotation technique and other commonly employed staining procedures proved the modified Sheather's technique to be most useful in identifying Cryptosporidium oocysts in diarrhoeal stools. This technique not only detected the parasite in the highest number of stools but also proved to be cost-effective and the least time-consuming. Other staining techniques assessed were the modified Ziehl-Neelsen, safranin-methylene blue and auramine-phenol fluorescence.

Association of serum antibodies to adherence lectin with invasive amebiasis and asymptomatic infection with pathogenic Entamoeba histolytica.

The recognition of the Entamoeba histolytica galactose-inhibitable adherence lectin by antibodies was studied using sera obtained from subjects in South Africa with an amebic liver abscess or asymptomatically pathogenic or nonpathogenic E. histolytica infection and from uninfected regional controls. In addition, sera from healthy American controls or Americans known to be infected with other parasites were studied.

Monoclonal antibodies directed against the galactose-binding lectin of Entamoeba histolytica enhance adherence.

The Entamoeba histolytica galactose-binding lectin is a surface glycoprotein composed of 170- and 35-kDa subunits. Inhibition of this lectin with galactose or anti-170 kDa subunit polyclonal antibody blocks amebic adherence to target cells and colonic mucin glycoproteins. We describe the properties of 10 mAb with specificity for the 170-kDa subunit.

Pathogenic and nonpathogenic strains of Entamoeba histolytica can be differentiated by monoclonal antibodies to the galactose-specific adherence lectin.

Entamoeba histolytica infection results in either asymptomatic colonization or invasive colitis and liver abscess. E. histolytica isolates from patients with invasive disease have characteristic isoenzyme profiles (pathogenic zymodemes), suggesting a role for parasite factors in determining the severity of infection.

Clinical diagnosis of cardiac beriberi.

The clinical features of 28 patients with biochemically proven cardiac beriberi were prospectively studied. Patients recruited over a 2-year-period fell into two groups: (i) those with signs of hyperdynamic circulation; and (ii) those presenting with heart failure and circulatory shock with or without metabolic acidosis. All patients showed a dramatic response to intravenous thiamine; in group 1 the hyperdynamic state resolved within hours and in group 2 there was an immediate rise in the blood pressure with gradual resolution of the acidosis in 6-8 hours.

Detection of Entamoeba histolytica immunoglobulins G and M to plasma membrane antigen by enzyme-linked immunosorbent assay.

Sixty-one serum specimens from 22 patients with clinically diagnosed amoebic liver abscess (ALA), 10 hospitalized patients with a variety of diseases other than amoebiasis, 12 normal healthy controls, and 17 subjects from an amoebiasis-endemic area were assayed by enzyme-linked immunosorbent assay (ELISA). The plasma membrane fraction of axenic cultures of Entamoeba histolytica HK9 separated from other subcellular fractions by differential centrifugation was used as the antigen to detect specific immunoglobulin G (IgG) and IgM antibodies. Using a single serum dilution of 1/100 and optical densities at 492 nm of 0.

Entamoeba histolytica: naturally occurring infections in baboons.

Entamoeba chattoni frequently occurs as an intestinal infection in non-human primates. It has been isolated from both wild and captive animals. Morphologically this amoeba resembles E.

Severe reversible myopathy due to typhoid.

An 18-year-old Black male presented to hospital with a fever and inability to walk due to severe proximal myopathy. He was found to have typhoid, and marked elevation of the creatine phosphokinase with myoglobinuria was recorded. After appropriate antibiotic therapy the creatine phosphokinase level returned to normal and the patient made a complete recovery.

Evaluation of an enzyme-linked immunosorbent assay in the serodiagnosis of amoebic liver abscess.

An indirect enzyme-linked immunosorbent assay (ELISA) was evaluated for the detection of anti-amoebic IgG and IgM antibodies to assess its value in distinguishing past from current infection in invasive amoebiasis, particularly in amoebic liver abscess (ALA) patients. Using sera from 295 individuals, the ELISA was also compared with the amoebic gel diffusion (AGD) test. In 100 patients the IgG-ELISA at a single test dilution of 1/6,400 had a sensitivity of 99% for clinically diagnosed ALA.

A longitudinal study of asymptomatic carriers of pathogenic zymodemes of Entamoeba histolytica.

The value of treating subjects who pass Entamoeba histolytica cysts in their faeces is currently in question. In the endemic Durban area iso-enzyme electrophoresis of E. histolytica isolates indicated that 1% of the asymptomatic population are infected with pathogenic zymodemes.