Laboratory diagnosis of Blastocystis spp. in diarrheic patients

Abstract

Background:Many laboratories currently diagnose Blastocystis spp. infections by looking for the presence of vacuolar forms in faeces and the amoeboid form in diarrheal stools.Objectives:To investigate the best direct method in diagnosis of Blastocystis spp. and to study different morphological forms of the parasite.Materials and Methods:The study was carried out on one thousand and two hundred diarrheic stool samples. All samples were examined using direct smear, iodine stained smear, formalin-ether concentration techniques, trichrome stained smear and in vitro cultivation using Jones' medium.Results:Using direct smear, Blastocystis spp was detected in 42 cases (3.5%) with a sensitivity (28.4%) and specificity (100%). Iodine stained smear detected 72 positive cases (6%) with a sensitivity (48.7%), specificity (100%). Formol ether concentration technique detected 120 positive cases (10%) with a sensitivity (81.1%) and specificity (100%). Trichrome stained smear detected 148 positive cases (12.3%). In vitro cultivation using Joni's medium detected 274 positive cases (22.8%) which was the highest number among all different diagnostic methods with a sensitivity (100%) ,specificity (88%), PPV (54.1%) and NPV (100%). It was found that, 49 blastocystosis cases had mixed infection with other intestinal parasites. Giardia lamblia was the most frequently associated parasite with Blastocystis spp.Conclusion:In vitro cultivation is more sensitive in detection of B. hominis than simple smear and concentration technique. Blastocystis spp. vacuolar form was the most common form that was found by all methods used in this study G. lamblia was the most frequent parasite associated with Blastocystis spp .

Multiplex Real-Time PCR Assay Targeting Eight Parasites Customized to the Korean Population: Potential Use for Detection in Diarrheal Stool Samples from Gastroenteritis Patients

“…However, the pathophysiology of Blastocystis infections in Korea remains undefined, and highly sensitive quantitative tools would increase our understanding of Blastocystis infections. Elghareeb et al found a wide range in diagnostic sensitivity between different Blastocystis detection methods [22]. Xenic in vitro cultures (XIVC) of Blastocystis exhibited a heightened positivity of 22.8%, compared to 12.3% with trichrome staining, 10.0% with formalin-ether concentration, 6.0% with an iodine-stained smear, and 3.5% with a direct smear [22].…”

“…Elghareeb et al found a wide range in diagnostic sensitivity between different Blastocystis detection methods [22]. Xenic in vitro cultures (XIVC) of Blastocystis exhibited a heightened positivity of 22.8%, compared to 12.3% with trichrome staining, 10.0% with formalin-ether concentration, 6.0% with an iodine-stained smear, and 3.5% with a direct smear [22]. Several PCR assays targeting the SSU rRNA gene have been previously developed for detection and discrimination among Blastocystis isolates directly in stool samples, and these assays have been more sensitive than XIVC [23].…”

Epidemiology and Prevalence of Blastocystis spp. in North Cyprus

“…infection was noted to be 24 (10.5%), 24 (10.5%), and 64 (27.8%), by direct microscopy, trichrome method, and PCR, respectively. Generally, stained and direct smear methods have lower sensitivity, 32,33 while PCR was found to be the most effective diagnostic approach. 25,34 Owing to the difficulty in collecting three consecutive stool samples, we obtained one specimen from each participant.…”

Akut İshali Olan ve Olmayan Çocuklarda Farklı Tanı Yöntemleriyle Blastocystis sp. Tanımlanması

“…Blastocystis spp. prevelansı gelişmiş ülkelerde %1,5-10, gelişmekte olan ülkelerde %30-60 arasında değişmektedir [1][2][3] . Zorunlu anaerop olup nötral pH'da 37ºC'de üremektedir 4 .…”

“…Zorunlu anaerop olup nötral pH'da 37ºC'de üremektedir 4 . Bilinen formları vakuolar, granular, multivakuolar, ameboid ve kistik formlardır 3 .…”