Diagnosis of giardiasis in asymptomatic and symptomatic patients using G. lamblia antigen[s] and IgA antibody in saliva

Giardiasis may be asymptomatic or symptomatic with possible extra-intestinal complications such as maculopapular rashes, polyarthritis and urticaria. Diagnosis by stool examination may give false negative results. Accurate exclusion of giardiasis is important to differentiate it from other causes of these manifestations. To assess the employment of saliva for diagnosing G. lamblia infections. The study attempted to determine the presence of G. lamblia antigen in human saliva by immunodiffusion technique and the associated specific secretory IgA [sIgA] immune response by immunoblot technique. Samples of saliva were collected from 80 subjects; 40 Giardia-infected individuals [symptomatic and asymptomatic], 20 subjects infected with other intestinal parasites and 20 healthy individuals as control groups of similar age and sex. Giardia cysts were collected from stools of heavily infected individuals, excysted and the harvested forms were cultivated on TYI-S-33 medium to prepare trophozoite antigen. The latter was used to produce hyperimmune serum in rabbits that was employed to detect the presence of specific antigen [s] in saliva by double gel immunodiffusion technique. Cysts were also used for antigen preparation which was fractionated by SDS-PAGE and tested to detect sIgA by immunoblotting of saliva samples. G. lamblia antigen was not detected in the saliva of any of the individuals enrolled in the study. Secretory IgA was detected in 75% of all infected individuals with 75% sensitivity and 90% specificity and in 90% of symptomatic and 60% of asymptomatic infected individuals. Molecular weight [MW] bands of 170 and 133 kDa were recognized by specific salivary sIgA by immunoblot analysis. Sensitivity and specificity of the 170 kDa band recognition were 75% and 90%, respectively with 88.2% and 78.2% positive [PPV] and negative [NPV] predictive values, respectively. The 133 kDa band gave 42.5% sensitivity, 100% specificity with 100% PPV and 62.3% NPV. Absence of specific antigen in the saliva refutes the assumption that G. lamblia antigens may reach the blood and questions the possibility of tissue invasion. The 170 and 133 kDa of Giardia cysts antigens form together useful molecules for diagnosis of giardiasis by IgA immunoblotting

Ancylostoma duodenale infection: a study of serum immunoglobulin G4 response to the excretory secretory antigen of adult worm

The serum anti-Ancylostoma duodenale immunoglobulin [Is] G4 antibody response to fraction III of the partially purified excretory secretory antigen of adult worm [Ad III ESA] was studied. This work included 60 patients with A duodenale infection [GI], 40 patients with other parasitic infections [GII] and 30 apparently healthy parasite-free controls [GIII]. Level of serum specific IgG4 was measured by indirect enzyme linked immunosorbent assay and compared with serum specific IgG, IgG 1, 2 and 3 subclass antibodies. Patients of GI had gastrointestinal manifestations and symptoms suggestive of anaemia and by investigations they had anaemia in 31.7% and eosinophilia in 100%. Measuring the intensity of A. duodenale infection, quantified as fecal egg counts, in patients of GI revealed that 60%, 30% and 10% had light, moderate and heavy infections, respectively. The serum anti-Ad III ESA IgG and IgG 1-4 subclass antibodies were significantly elevated in patients of GI compared with GIII. Serum specific IgG4 was expressed in 100% of patients of GI at a significantly highly elevated level than IgG1, IgG2 and IgG3. Specific IgG1 was expressed in 88.3% of patients of GI at a significantly elevated level than IgG2 and IgG3 which were expressed in 31.7% and 38.3%, respectively, and elevated to a moderate extent. Serum specific IgG4 showed a 1.0, 1.1, 3.1 and 2.6-fold increase in detection rate of positive cases than IgG, IgG1, IgG2 and IgG3, respectively. The highest ability to differentiate between infected and healthy subjects was by serum specific IgG4 recording a discrimination coefficient of 9.4, while IgG, IgG1, IgG2 and IgG3 recorded 5.2, 6.3, 3.2 and 3.4,respectively. Serum specific IgG4 showed a significant positive correlation with the intensity of A. duodenale infection demonstrated by IgG and IgG3, respectively. Detection of serum anti-Ad III ESA IgG4 antibody recorded a 100% sensitivity that was significantly higher than IgG1, IgG2 and IgG3, but insignificantly different from IgG. Finally, serum specific IgG4 recorded a 100% specificity that was significantly higher than IgG, IgG2, IgG3 and IgG1. They showed cross-reactions with ascariasis, lymphatic filariasis and strongyloidiasis. The results were discussed

Pulmonary trichomoniasis: improved diagnosis by using polymerase chain reaction targeting trichomonas tenax 18Sr -RNA gene in sputum specimens

This study included 250 individuals [100 immunocompromised patients with chest complaints [group I], 100 patients with chronic pulmonary diseases [group II] and 50 healthy individuals as controls [group III]]. Twenty cases were positive in one or more methods giving for pulmonary trichomoniasis [a total prevalence of 8%; 12% in group I and 8% in group II and none in group III], with no significant difference between groups I and II. Pulmonary trichomoniasis was prevalent at an age ranged between 31-50 years and in males [10%] than females [5.5%] with no significant difference. Among the 200 examined patients, pulmonary trichomoniasis had a prevalence of 3% by wet mount. 2.5% by Giemsa-stained smear, 7% by culture compared with 10% by polymerase chain reaction [PCR]. Culture was used as a reference standard. All culture positive specimens were PCR positive, showing a product at 0.8 Kb long by agarose gel electrophoresis and 100% sensitivity. Wet mount, Giemsa-stained smear and culture had a sensitivity of 43%, 35.7% and 70%, respectively. No PCR negative specimens were positive by any of the other methods. Six specimens were culture negative PCR positive and remained PCR positive when retested three times. The calculated specificity of PCR was 97%. No PCR target product was amplified with DNAs of T. vaginalis and various pulmonary pathogens. The results were discussed

Human giardiasis as an etiology of skin allergy: the role of adhesion molecules and interleukin - 6

In this work, the role of adhesion molecules [intercellular adhesion molecule-1 [ICAM-1] and vascular cell adhesion molecule-1 [VCAM-1]] as mediators in the development of skin allergy caused by giardiasis and the controlling role of cytokine interleukin [IL]-6 on these adhesion molecules were studied. The work included 25 symptomatic giardiasis patients with skin allergy manifested by diffuse urticaria, pruritis, wheal and erythema as well as had positive serum anti-giardia immunoglobulin [Ig] E measured as the mean optical density [OD] value by enzyme linked immunosorbent assay [ELISA], employed as an evidence of allergic sensitization [G I]. Those patients were compared with 30 symptomatic giardiasis patients [G II] and 20 apparently healthy control subjects [G III]. Both latter groups had negative serum anti- giardia IgE. The mean OD value of anti-giardia IgE was significantly increased in G I and insignificantly different in G II compared with G III. The serum levels of the soluble forms of adhesion molecules [sICAM-1 and sVCAM-1] and IL-6 were determined by ELISA. SICAM-1 and sVCAM-1 serum levels were significantly increased in G I compared with G III, showing an insignificant difference between Gs II and III. Serum IL-6 significantly increased in G I and G II compared with G III as well as and was significantly higher in G I than G II. Serum IL-6 was correlated positively with serum sICAM-1 and sVCAM-1 in G I

Alkaline phosphatase from echinococcus granulosus meyacestodes for immunodiagnosis of human cystic echinococcosis

This work examined the use of Echinococcus granulosus alkaline phosphatase [EgAP] [extracted from hydatid cyst membranes] as an antigen for the immunodiagnosis of human cystic echinococcosis [CE]. It was assessed by enzyme-linked immunosorbent assay [ELISA] and Western immunoblotting [IB] for the detection of serum anti-EgAP immunoglobulin [Ig]G antibody and was compared with hydatid cyst fluid [HCF]. The EgAP and HCF were of sheep liver cysts origin. Sera from 30 patients with surgically confirmed CE [G I], 30 patients with other parasitic infections [G II] and 20 healthy controls [G III] were examined. The mean optical density of each of anti-EgAP IgG and anti- HCF IgG antibodies in G I was significantly higher than in each of G II and III. The use of EgAP in ELISA showed 100% sensitivity and specificity, which were significantly higher than when using HCF in ELISA [86.7% sensitivity and 84% specificity]. SDS-PAGE resolution, under reducing conditions, of EgAP revealed a molecular weight of 56 kDa, while that of HCF revealed a number of antigenic bands ranged from 12-130 kDa. IB analysis showed that sera from CE patients recognized the EgAP 56 kDa and also one or more of HCF antigenic bands of molecular weights at 116, 63, 44, 39, 24, 20, 16 and 12 kDa. The use of EgAP in IB showed 100% sensitivity and specificity recording an insignificant difference in sensitivity and a significantly higher specificity than when using HCF in IB [100% sensitivity and 90% specificity]. Cross reactivity with HCF in ELISA and IB was seen with Schistosomiasis mansoni, fascioliasis, Hymenolepiasis nana and ascariasis. Using EgAP, there was an insignificant difference in each of the sensitivity and specificity between ELISA and IB. Using HCF, there was a significantly higher sensitivity and an insignificantly higher specificity by IB than ELISA. The implications of these results were discussed

Secretory and humoral antibody responses to blastocystis hominis in symptomatic and asymptomatic human infections

This study included three groups of individuals: In the first two groups, they had positive stool microscopic examinations only for B. hominis indicating blastocystosis with and without gastrointestinal symptoms, respectively; while, the last group included apparently healthy individuals with no parasites in stool. Stool and serum samples of these individuals were subjected to the detection of anti- B. Hominis fecal and serum IgA and IgG antibodies by indirect ELISA and the detection of B. Hominis fecal and serum antigens by double sandwich ELISA

Cystatin capture-dot-enzyme-linked immunosorbent assay for immunodiagnosis and assessment of cure of experimental trichinellosis in mice

Cystatin capture-dot-enzyme-linked immunosorbent assay [CC-dot ELISA] was evaluated as a new version of ELISA for the diagnosis of trichinellosis by the detection of anti-Trichinella spiralis cysteine proteinase [CyP] IgG using nitrocellulose membrane sensitized with cystatin as a capture reagent for CyP from T. Spiralis muscle larvae excretory secretary products [ESP] without purification compared with the detection of anti-T. spiralis IgG by conventional [conv.] ELISA using whole ESP. Experimentally infected mice with light [100 larvae/mouse] and heavy [300 larvae/mouse] infections by T. spirals larvae at 7, 14, 21 and 56 days post-infection and after flubendazole treatment were examined

Role of nitric oxxide in host defense against Hymenolepis nama infection

The defensive role of nitric oxide [NO] against Hymenolepis nana was investigated in vivo and in vitro studies. Serum NO levels were increased in mice 5 days [cysticercoid stage] and 15 days [adult stage] after H. Nana induced oral infection with 1000 eggs/mouse compared with the normal controls. Meanwhile, L-NAME, a NO synthase inhibitor, oral administration in drinking water to infected mice caused a nonsignificant decrease in the serum NO levels compared with the normal controls and was associated with a significant increase in the number of both cysticercoids and adult worms compared with that in infected mice 5 and 15 days post infection. In an in vitro study, the NO donor, sodium nitroprusside caused an increased mortality rate of H. Nana cysticercoids and adult worms compared with the controls without NO donor and this was in a concentration-dependent manner. The implications of these results were discussed

use of Ziehl-Neelsen stain, enzyme-linked immunosorbent assay and nested polymerase chain reaction in diagnosis of cryptosporidiosis in immuno-competent,- compromised patients

In the present study, Cryptosporidium parvum was diagnosed in stool by Ziehl-Neelsen [Z-N] stain, enzyme linked immunosorbent assay [ELISA] and polymerase chain reaction [PCR]. The detected cases were 5.3%, 8.3% and 9.6% by the previous three methods, respectively. The sensitivity, specificity and accuracy of the different techniques were evaluated. The Z-N stain showed the lowest sensitivity and accuracy in relation to either ELISA or PCR. Moreover, the study revealed that the sensitivity, specificity and accuracy of ELISA detection of Cryptosporidium in relation to the detection of DNA in stool by PCR were 84.2%, 96% and 88.8%, respectively. Consequently, PCR showed the best results. From a practical point of view, ELISA was recommended for widespread use in the diagnosis of cryptosporidiosis

preliminary study on the relationship between trichomonas vaginalis and cervical cancer in Egyptian women

The relationship between Trichomonas vaginalis and cancer cervix was investigated by detection of T. vaginalis antibodies in the sera of 48 invasive cervical cancer patients and 100 random age matched female controls using western immunoblot technique. It was found that antibodies to T. vaginalis were detected in sera of 18.75% of cervical cancer patients compared with 5% of the controls. The increase was evident in the age group 40-49 years and of those with squamous cell carcinoma [6/9] and mainly with grades II and III. All the reactive sera of invasive cancer patients reacted strongly with T. Vaginalis surface antigen of about 109.9, 86.1, 56.2, 48.2 and 30 Kda. So, there may be an association between T. vaginalis and the risk of cervical cancer, as there was more than 3-fold increase in the prevalence of T. Vaginalis antibodies in patients with invasive cervical cancer compared with the age matched female controls. This study highlighted the importance of clinically detection of T. vaginalis infection, which is among the factors involved in the genesis and progression of cervical cancer. In addition, its treatment would aid in restricting the rising incidence of this disease

Effect of the iron chelator deferoxamine on trichomonas vaginalis in vitro

The effect of 10 muMol, 15 muMol, 30 muMol and 60 muMol concentrations of deferoxamine [DFO], a clinically approved iron chelator, was determined on viability and multiplication of Trichomonas vaginalis grown in TYM axenic culture medium at 24 hours interval. DFO killed all T. vaginalis isolates with a minimum lethal concentration of 30 muMol after 48 hours culture incubation with the drug. A potent and persistent inhibitory effect of DFO on the parasite viability and multiplication was recorded throughout the study in a drug concentration and time exposure-dependent manner. Furthermore, this work studied the proteinase activity of T. vaginalis grown for 48 hours in DFO inoculated TYM medium and recorded a significant decrease by all drug concentrations applied. Different possible mechanisms of action of DFO against vaginalis and its possible use for treatment of trichomoniasis are discussed in this study

Effect of deferoxamine alone and combined with pyrimethamine on acute toxoplasmosis in mice

The standard regimen of treatment for toxoplasmosis is pyrimethamine with sulfadiazine. However, it is not suitable in some conditions and non-tolerable in AIDs patients. Deferoxamine [DFO], an iron chelator, is well tolerated clinically in transfusion induced-iron overload. The present study had shown that DFO is a promising drug against acute toxoplasmosis in mice. Three doses of 200, 300 and 400 mg/kg DFO were used either alone or in combination with pyrimethamine. Singly, it was effective in a dose-related response with the resultant of 70% protection of infected mice. When DFO was combined with a low minimally effective dose of pyrimethamine, a 100% protection was recorded with the prolongation in duration of survival of mice. Different possible mechanisms of action of DFO against Toxoplasma gondii were discussed

Detection of hydatid antigen in human cyst fluid by reverse latex agglutination test

The present work studied the use of reverse latex agglutination [RLA] test in the diagnosis of CE as a test that could directly detect hydatid antigen in human cyst fluid samples. The results were reliable when compared with the direct microscopic examination of cyst fluid samples. Also, it was more reliable than indirect hemagglutination test as it showed 100% sensitivity. No false positive reaction was observed with samples from cystic tumors with a resultant specificity of 100%. Moreover, the test is easy to perform with a visually interpreted results within 2-3 minutes. The reagents are inexpensive, stable and easily available. These merits make the RLA test suitable for the diagnosis of CE, particularly in suspected cases with seronegative results or cases with sterile cysts

Diagnosis of symptomatic and asymptomatic trichomonas vaginalis infection by applying one tube nested pcr to vaginal discharge

One tube nested PCR targeting a species-specific Tv-E650 repeat family of T. vaginalis genome was applied to vaginal discharge specimen to diagnose symptomatic and asymptomatic trichomoniasis. The test was compared with axenic culture examination, wet mount preparation and Papanicolaou stained smears. A total of 450 cases, symptomatic and symptomatic, was collected over 2 years. Out of 290 symptomatic women with cervicovaginitis and 160 asymptomatic women, 35 were culture positive for trichomoniasis. All culture positive specimens were PCR- positive, giving a single product at 290 bp by agarose gel electrophoresis and recording 100% sensitivity similar to culture examination. Among the 35 culture positive specimens, 12 were positive by wet mount and 21 were positive by Pap smear, giving a 34.2% and 60% sensitivity, respectively. The standard and boiling DNA extraction methods were equally reliable, but the latter was more simple, rapid and cheap. No specimens negative by PCR for trichomoniasis were positive by culture, wet mount or Pap smear. Moreover, specimens from cases with cervicovaginitis of non- trichomonal origin were negative by PCR