Prevalence and molecular identification of Giardia intestinalis in water buffalo in Iraq

Giardia is the most prevalent flagellated protozoan in humans and other mammals. It causes significant economic losses in livestock, including water buffaloes.

This study aimed to determine the prevalence rate of Giardia intestinalis in water buffaloes (Bubalus bubalis) using microscopic and molecular techniques and to detect the genotypes of Giardia isolates from water buffaloes in Iraq.

A total of 180 fecal samples (82 males, 98 females) were collected from water buffaloes in the Babylon province. The microscopic method was used to determine the infection rate of G. intestinalis in water buffalo in the Babylon province. DNA was extracted using the fecal lysis procedure and proteinase K, nested-polymerase chain reaction (PCR) was used to identify the prevalence of Giardia assemblages in water buffalo, targeting the triose phosphate isomerase (TPI) gene. Ten PCR-positive samples were sent for sequence analysis.

The infection rate of G. intestinalis was 13.88% using the conventional microscopic method and 30.55% using nested PCR in water buffalo. There was no significant difference in the prevalence of Giardia between males (29.26%) and females (31.63%). The largest infection rate was observed in buffaloes aged 1 year (34.24%), while the lowest was observed in those aged 3 years (26.66%). Phylogenetic analysis identified two genotypes of G. intestinalis, assemblages A and B, in Iraqi water buffaloes.

The identification of G. intestinalis assemblages A and B in buffalo indicated that buffalo acts as a reservoir host and may be a source of zoonotic transmission.