1.First report of detection of IgA anti-Acanthamoeba antibodies among Saudi population and amoeba isolation from their surroundings
Alouffi, A.S. ; Dawoud, T.M. ; Almaary, K.S. ; Mubarak, A.S. ; JarAllah, K. ; Matin, A.
Tropical Biomedicine 2021;38(No.1):73-80
Acanthamoeba is an opportunistic protozoan pathogen which is found in diverse environment
worldwide. Being ubiquitous nature of this amoeba we come across it in our daily life.
Acanthamoeba species are recognized as human pathogens; that may cause blinding keratitis
and rare but fatal granulomatous encephalitis involving central nervous system. To date,
there is not a single report in literature demonstrating anti-Acanthamoeba antibodies among
the Saudi population, and thus aim of the present study. Using ELISA, we identified the
antibody level in the local population. Our results represent the secretory IgA antiAcanthamoeba in mucosal secretions from 133 individuals aged 15–60 years. The antiAcanthamoeba antibody prevalence rate was > 80%, and no considerable differences were
observed between prevalence in males (80.28%) and that in females (80.64%). In addition,
environmental sources (soil and water) from the environment of the participants in our
study were evaluated for amoeba incidence. The amoeba was identified by morphological
characteristics of cysts or trophozoites on non-nutrient agar plates grown with E. coli. Overall,
58.75% of samples from water and 32.85% of those from soil were culture positive for outgrowth
of amoeba on non-nutrient agar plates. Furthermore, PCR was carried out with genus-specific
primers to confirm the presence of Acanthamoeba DNA. Our results revealed that about 68%
of cultures from water and 43% of those from soil were successfully amplified and proved to
be amoeba DNA. Interestingly, a few samples yielded more than one product, which suggests
that some other amoebic species may be present in the same sample (MAC-W1 and MADW1). To the best of our knowledge, we described for the first time the amoeba isolation from
the participant’s close environment and antibodies level among Saudi population. Our
future studies will be focused on additional molecular characterization of isolated amoeba
and their pathogenic potential which could be a possible threat for the community.