Extraction of the DNA of Giardia lamblia isolated from vegetables and fruits in a simplified way and its diagnosis using Nested-PCR.

Giardiasis is one of the main diseases transmitted by food contaminated with infectious stages. It was usually spread through freshly eaten food. In this study, this parasite was diagnosed based on microscopic diagnosis of isolated samples of vegetables and fruits, as well as molecular diagnosis. The possibility of isolating parasites from vegetables and fruits and extract DNA to be used in most laboratories were verified in this study .The prevalence of Giardia lamblia were estimated on vegetables and fruits without the need to purchase a special extraction kit. .The prevalence of Giardia on fresh vegetables was estimated by using wet direct swab with Lugol's iodine dye in microscopic examination, at a rate of 4 positive samples out of 230 of all studied species, or 1.7%. DNA extraction was carried out for all samples, and 102 DNA samples were extracted from all samples, with a percentage of 44.3%. Moreover, the shown results of the nested PCR test for the 16 S rRNA gene on the obtained DNA the prevalence of Giardia lamblia at a rate of 5.9% from DNA samples isolated from vegetables and fruits.

Phylogenetic tree of Blastocystis hominis in Iraqi children in Salah AL-Deen province, Iraq.

Blastocystis hominis is an intestinal protozoan that inhabits the large intestine of humans and a wide range of animals. Blastocystis species has a worldwide distribution. The current study aimed to determine the prevalence and the genetic variety of Blastocystis sp. in Iraqi children in Salah AL-Deen province, Iraq. 150 faecal samples were collected from children (5-10 years old) who attended the Salah AL-Deen hospital during the period from March to November 2020. The results revealed that 33.3% of children (50 out of 150) were found infected with Blastocystis sp., when the polymerase chain reaction (PCR) was used. The presence of ST3 gene was at a band of 526 bp where this gene was observed in 11 samples out of 50 samples. The results also showed significant differences in the prevalence rate between rural and urban regions; between symptomatic and asymptomatic children, and between children who contacted domestic animals and those who did not contact animals (P<0.05). No significant differences in the prevalence rate were between different age groups (P>0.05). Regarding the genetic variation in subtype 3(ST3) revealed in phylogenetic tree analysis, there were three variations (transversion, deletion, and transition) which were detected through the sequence alignment, also the similarity was 97% with the sequences of Blastocystis sp. registered in GenBank. The Iraqi ST3 isolate was registered with ID: OL410286 in GenBank.