Epidemiological and Molecular Characterization of Blastocystis Infection in Children Attending Daycare Centers in Medellín, Colombia

Background: The present study aims to perform an epidemiological and molecular characterization of Blastocystis infection in a child population attending daycare centers of Medellín, Colombia. Methods: A total of 265 children aged 0–5 years were enrolled in five children’s centers in urban sectors of Medellín, northwestern Colombia. Stool samples were taken to identify intestinal parasites by direct examination, Ritchie–Frick concentration, and molecular identification of Blastocystis by conventional PCR and subtype (ST) identification by PCR barcoding with subsequent phylogenetic reconstruction. Kappa index was calculated to evaluate the agreement between microscopy and PCR for the diagnosis of Blastocystis. Results: The prevalence of intestinal protozoa was 36.6% (97/265), with Blastocystis as the most frequent parasitic protozoan at 15.8% (42/265), followed by Giardia intestinalis at 15.5% (41/265) and Endolimax nana at 15.1% (40/265). The prevalence of Blastocystis by PCR was 53.2% (141/265), the subtypes identified were ST3 at 30.5% (18/59), ST2 at 23.7% (14/59), ST1 at 20.3% (12/59), and with less frequency, ST4 at 5.1% (3/59), ST6 at 1.7% (1/59) and ST16 at 15.3% (9/59) allele 162. Conclusion: This study provides the first genetic characterization of Blastocystis subtypes circulating in a population of Medellín, Colombia, and also updates the epidemiology of Blastocystis subtypes in the world with the first identification of ST16 in humans.

The Prevalence of Blastocystis Infection in Pediatric Patients with Malignancy: A Single-Center Study in Ahvaz, Iran

Background: Blastocystis spp. is known as one of the few intestinal parasites, prevalent in more than 5% and 30 - 60% of the population in industrialized and developing countries, respectively. In this respect, immunocompromised individuals, such as patients undergoing chemotherapy or those with malignancies, are at risk of the clinical symptoms of Blastocystis infection; however, the given condition is often self-limiting in healthy individuals. Objectives: The current study aimed at evaluating the prevalence of Blastocystis infection in children with malignancies receiving chemo drugs. Methods: The current descriptive, cross-sectional study was conducted on 52 stool specimens collected from patients with cancer admitted to the Oncology Ward of Shahid Baqaei 2 Hospital, Ahvaz, Iran, for six months. A standardized questionnaire was filled out for all cases. Each specimen was also prepared using direct smear, the Lugol iodine staining, and the formalin-ether condensation method. Results: Blastocystis spp. was detected in 21.1% of the cases among them, 11.5% demonstrated gastrointestinal symptoms; therefore, a significant relationship was observed between Blastocystis infection and gastrointestinal symptoms. Conclusion: Patients undergoing chemotherapy should be screened for opportunistic parasitic infections such as Blastocystis to avoid potentially life-threatening outcomes. Besides, further studies are required to identify the subtypes of Blastocystis.

Prevalence and Subtype Distribution of Blastocystis Infection in Patients with Diabetes Mellitus in Thailand

Diabetes mellitus (DM) is a major global public health problem with an increasing prevalence. DM increases the risk of infections caused by bacteria, fungi, viruses, and parasites. We examined the prevalence, subtypes, and risk factors of Blastocystis infection in patients with and without DM in central Thailand. Stool samples and questionnaires were obtained from 130 people in the DM group and 100 people in the non-DM group. Blastocystis infection was identified via a nested polymerase chain reaction and subtyped via sequencing of the partial small-subunit ribosomal RNA (SSU rRNA) gene. Analysis of potential risk factors was conducted via binary logistic regression. The overall prevalence of Blastocystis infection was 10.8%, including rates of 9% and 12.3% in the non-DM and DM groups, respectively. The most prevalent subtype was ST3, followed by ST1, and ST4. Factors that potentially increased the risk of Blastocystis infection include patients being >65 years old, the presence of DM, a DM duration of ≥10 years, a low level of education, and animal ownership. In conclusion, this is the first study of Blastocystis infection in DM, and a high prevalence was found among this population. Therefore, health education promoting sanitation and hygiene is necessary to reduce and prevent infection in the community.

Blastocystis sp. : Evaluation of polyclonal antibody prepared from crude protein for serological diagnosis using Rabbit serum

The diagnosis of Blastocystis infection is still based on the clinical sign which is not specific and there is no available serologic test for it. This study aimed to evaluate the polyclonal antibody prepared form crude protein of Blastocystis for the development of the Blastocystis serological test. Crude protein was extracted from the yeast of Blastocystis sp, then inoculated into rabbits to produce the antibody of crude protein. The serum of rabbits would be collected before and after immunization to compare the antibody titer. The profile of crude protein was analyzed using SDS-Page. The rabbit serum was analyzed using ELISA and Western Blot. The SDS-Page result showed bands in 100 kDa, 90 kDa, 70 kDa, 60 kDa, 58 kDa, 50 kDa, 40 kDa, 35 kDa, 30 kDa and 27 kDa. The ELISA assay showed that there was an increase in antibody titer of crude protein after immunization. Western Blot showed that three proteins (30 kDa, 40 kDa and 50 kDa) having immunogenicity characteristic. It is concluded that protein 30 kDa, 40 kDa and 50 kDa prepared from the crude protein of Blastocystis sp. can be used for developing a serologic test for Blastocystis infection. Keywords: Blastocystis sp, Crude Protein, Polyclonal Antibody .