Detection and Genotyping of Giardia lamblia in Clinical and Environmental Samples in Some Regions of Baghdad city

Abstract

The present study was conducted to estimate the prevalence of Giardia lamblia infection in some regions of Baghdad city, the relationship of source of drinking water with the prevalence of this intestinal protozoal parasite had been evaluate, The study revealed that the total rate of G.lamblia infection in humans was 68/375 (18.13%) according to three diagnostic methods, there was significant relation (p≤0.01) between infectivity rate (25%) of this parasite and persons who consumed tap water as a source of drinking water as compared to other source of drinking water. RT-PCR tpi gene application was able to detected and genotyping G.lamblia to assemblage A and B, since mix infection of assemblage (A+B) are more prevalent in fecal samples than others, while in environmental samples the assemblage A, assemblage B showed in 1/4 (25%), 2/4(50%) respectively and mixed assemblage (A+B) showed in 1/4 (25%) of samples. K e y w o r d s Giardia lamblia,Genotyping, infectivity rate, RT-PCR tpi gene.

Assessment of Potable Water Quality in Baghdad City, Iraq

“…Tigris River is the main water supply for Baghdad city. 11 However, since April 2003, in Baghdad city, bottled water with 20-L capacity has gained a position in the market because of tap water pollution. The uncertainty of tap water quality after war has caused an increase in the number of local water treatment shops around Baghdad.…”

Molecular genotyping of Giardia lamblia assemblages by conventional PCR in rural and urban areas in Egypt.

“…Of 92 microscopically positive fresh fecal samples, 88 (95.7%) displayed positive results by PCR. Similarly, Molina et al [10], Abbas et al [5], and Chakarova et al [7] reported that 82%, 93%, and 94% of their fecal samples revealed positive results by PCR in Argentina, Iraq, and Bulgaria, respectively. The failure of DNA amplification and false negative results for some samples may be due to the low concentration of DNA, handling error and presence of some PCR inhibitors [5].…”

“…In the United States, it was reported that the average number of G. lamblia infected cases during 1995-2016 was 19781 cases per year [4]. Giardiasis clinical manifestations may be asymptomatic or symptomatic with acute or chronic diarrhea associated with abdominal cramps, vomiting, abdominal pain, fatigue, nausea, weight loss, damage of the small intestinal mucosal surface, and malabsorption [5,6]. Giardiasis is usually self-limited in immune-competent individuals; however, it can cause severe and fatal diarrhea in immunecompromised individuals and children, depending on host immune response and the virulence of Giardia genotype [7].…”

“…Giardiasis occurs through consumption of food or water harboring Giardia cysts or by the fecal-oral route. Trophozoites are the vegetative active stages that live and multiply in the upper small intestine where they adhere and cause giardiasis signs and symptoms [5].…”

“…Polymerase chain reaction (PCR) and other molecular techniques revealed that there are eight morphologically indistinguishable G. lamblia assemblages (A -H) that differ in the sequence of the glutamate dehydrogenase, small subunit rRNA, and triose phosphate isomerase (tpi) genes. So far, assemblages C-H have not been detected in humans; however, assemblages A and B or "Polish" and "Belgian" are potentially zoonotic human pathogens [5,11]. To date, the distribution of assemblages of G. lamblia in different countries have been presented [7].…”