Polymerase chain reaction versus conventional methods in the diagnosis of vaginal trichomoniasis.

A total of 200 females of whom 120 had manifestations of vaginal trichomoniasis and 80 asymptomatic ones were studied. In 54/120 symptomatic female (45%) and in 28/80 asymptomatic ones (35%), T. vaginalis was diagnosed by wet mount of bedside vaginal swab samples. Of 120 samples from symptomatic females, T. vaginalis was detected in 93 (77.5%) when cultured onto InPouch & 95 (79.16%) in modified thioglycolate media. Culturing 80 samples of asymptomatic females showed T. vaginalis in 35 (43.75%) onto either media. T. vaginalis genomic DNAs was amplified by PCR from 130 (65%) by using TVA5-TVA6 primer pair in 95 (79.16%) samples of 120 symptomatic females, and in 35 (43.75%) samples of 80 asymptomatic ones. Difference between groups was statistically significant. The motile trichomonads was detected by wet mount in 82/130 positive cultures giving 63.07% sensitivity & 100% positive predictive value (PPV). Flagellates were not detected by wet mount in any negative culture, giving 100% specificity & 59.32% negative predictive value (NPV). The wet mount diagnostic accuracy (DA) was 76%, without false-positive, but false negative was 48/130 (36.93%). DNA was amplified from 129/130 positive culture by TVA5-TVA6 primer pair, giving 99.23% sensitivity. No amplification was detected from one positive culture. DNA was not amplified from 69/70 negative culture using TVA5-TVA6 primer pair, giving 98.57% specificity, 99.23% PPV, 98.57% NPV and 99% DA.

Protein profile and morphometry of cultured human Blastocystis hominis from children with gastroenteritis and healthy ones.

A total of 180 children of age group 5-12 years old in both sexes, of whom 90 were symptomatic and negative for other parasites, rotavirus or pathogenic bacteria. Another 90 children were asymptomatic, but with B. hominis in stools. Direct smear, formaline-ethyl acetate sedimentation concentration, kinyon carbol-fuchin stain, stool culture, enzyme immunoassay, culturing, morphometric study, gel electrophoresis and experimental infection of mice were done. The results showed that the central body cysts (CB), granular and multivacuolar forms isolated from symptomatic patients were larger than those from asymptomatic ones. The CB form was common compared to other forms and isolated from 104 cases. B. hominis infection was prevalent among males rather than females (60.5% versus 39.5%). The clinical data showed that diarrhea was the most common symptom (58.9%). The infection intensity had a direct relation with illness duration. The polyacrylamide gel electrophoresis showed that isolates from symptomatic and asymptomatic patients ranged between 24-130 kDa. All isolates showed similar banding patterns. Only minor differences was in low MW (30, 50 kDa) and in high MW (118 kDa) in samples from symptomatic patients. The histopathological examination of caecum, colon and small intestine of B. hominis mice infected from symptommatic patients showed infiltration with inflammatory cells and tissue invasion by the parasite.

Bacillus thuringiensis var. israelensis as a microbial control agent against adult and immature stages of the sandfly, Phlebotomus papatasi under laboratory conditions.

The laboratory treatment of adult and immature stages of Phlebotomus papatasi by the bacterial insecticide, Bacillus thurnigiensis var. israelensis was carried out. Different concentrations of B.t.i. mixed with fructose and glucose were assayed against the adult sandfly, while the immature stages were treated by offering larval diet contaminated by B.t.i. in different concentrations diluted by distilled water. B.t.i. could induce mortality to half of the larval and pupal population at 0.26 x 10(-5) g/L. The median lethal doses of adults which were fed on contaminated surgery diet with serial dilutions of B.t.i. were 1.3 x 10(-2) g/L with fructose, and 3 x 10(-2) g/L with glucose after 48 and 72 hrs. The longevity period of larvae and pupae fed on contaminated larval diet showed negative correlation with bacterial concentrations except for highly concentrations. The bacterial control of the sandfly, Ph. papatasi could be recommended particularly as adulticide agent.

Total salivary gland proteins of female Culex pipiens and Aedes caspius (Diptera: Culicidae) and their fractionation during adult development and after blood sucking.

Salivary glands of Culex pipiens and Aedes caspius were analyzed to determine total protein content and its fractionation during adult female development and after blood sucking. In both species, the molecular weight of proteins ranged between 26.000 and 84.000 Daltons. These proteins were not identical in the two species. In Cx. pipiens, the total protein level increased during the first 3 days of adult development from 4.94 +/- 0.84 to 6.6 +/- 0.37 micrograms/gland. During this period, the salivary gland proteins were separated into 35, 34 and 37 fractions respectively. Cx. pipiens released in the human host 64% of the total proteins while taking a blood meal compared to unfed females. This decrease in protein level was proportional to protein fractions. Over the next 6 days, the protein level increased again to attain values comparable to those obtained prior to blood sucking. In Ae. caspius, the total protein level of the salivary glands did not change during the first 4 days of adult development (range between 3.13 +/- 0.27 and 3.91 +/- 0.36 micrograms gland), but on the fifth day, 2-fold increase was observed. The total salivary gland protein increased during the next 3 days after blood sucking to reach 15.5 +/- 0.98 micrograms/gland. During this period, a tremendous change in protein patterns was observed. After oviposition, on the fourth day, a significant reduction in the total protein level was observed (4.13 +/- 0.56 micrograms/gland), but over the next 3 days the level increased again (range between 4.13 +/- 0.66 and 7.13 +/- 0.66 micrograms/gland).

Immunofluorescent detection of both Giardia lamblia and Cryptosporidium parvum using anti-Cryptosporidium oocyst antibodies.

Giardia lamblia and Cryptosporidium parvum are two protozoal parasites proved to have a major role in gastroenteritis in humans. Both are documented to coexist in many waterborne parasitic transmission, as well as in outbreaks. In the present work, a polyspecific anti-Cryptosporidium oocyst antibodies were used for simultaneous detection of both parasites in human stool. Known positive formalinized human stool specimens of Giardia sp. (n = 10), Cryptosporidium sp. (n = 7), mixed infection (n = 3), and negative specimens (n = 20), were tested using direct fluorescent technique against the developed antibodies. All positive stool samples for Cryptosporidium and 9 out of 10 Giardia samples, or each alone showed fluorescence with variable intensities, while no negative sample harboured other parasites had fluorescence. This newly used polyspecific antibodies offer the advantages of screening large number of patients, particularly in outbreaks. Additionally, it represents a cheaper alternative for the most sophisticated and costly immunoassay kits using the monoclonal antibodies, with more or less the same diagnostic potentials.

Evaluation of five stains in diagnosing human intestinal coccidiosis.

Three hundreds cases over the year 1998 complaining of diarrhoea were examined. The stools were examined by the traditional diagnostic methods and confirmed to be free from intestinal parasites. Cryptosporidium parvum, Isospora belli and Cyclospora cayetanensis were detected by using different types of faecal stains namely modified Ziehl-Neelsen, Kinyoun acid-fast, Auramine-rhodamine, Gomori's trichrome and Giemsa. The number of positive cases were 87 C. parvum (29%), 5 cases L. belli (1.7%) and 12 cases C. cayetanensis (4%). This study showed that the sensitivity of modified Ziehl-Neelsen and Kinyoun Acid-fast were very high (100%) in comparison with the other stains.

Opportunistic intestinal protozoal infections in immunocompromised children.

Hundred immunocompromised children and 100 house contact controls were chosen. Patients included: 52 nephrotic syndrome children receiving corticosteroids for more than one month (age 5.28 +/- 2.32 years), 14 protein-calorie malnutrition (PCM) patients (8 cases of marasmus aged 6 +/- 2.27 months and 6 cases of marasmic kwashiorkor aged 1.39 +/- 0.88 years) and 34 lymphomas patients (22 cases of Hodgkin's disease and 12 cases of non-Hodgkin's lymphoma; age 4.5 +/- 3.54 years). Examination of concentrated stool was done using iodine stain of fresh mounts and modified Ziehl-Neelsen (cold acid-fast) to fixed smears. T-cell subsets were counted after staining with mouse monoclonal antibodies against CD4 and CD8 labeled with fluorescein. Both nephrotic syndrome and lymphomas groups showed affection of cellular immunity in the form of significant decrease in T-helper and H/S ratio and significant increase in suppressor T-cell subsets. Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum and Blastocystis hominis were the most frequent in patients group and were significantly more prevalent among patients than controls. No significant difference in the prevalence of Entamoeba coli and Chylomastix mesnili between the two groups. C. parvum infection were strictly confined to groups with T-cell subsets abnormalities i.e. nephrotic syndrome and lymphomas groups.