First report of detection of IgA anti-Acanthamoeba antibodies among Saudi population and amoeba isolation from their surroundings

@#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.

Molecular detection of Candidatus Anaplasma camelii in camels (Camelus dromedarius) from Asir Province, Saudi Arabia

@#Knowledge of molecular identification of tick-borne pathogens in camels in Saudi Arabia is very limited; few molecular epidemiological studies have been under taken. This study was to detect Anaplasma spp. and Piroplasma spp. in camels from Asir Province, Saudi Arabia. A total of 150 blood samples were collected from camels in Asir Province and investigated by polymerase chain reaction (PCR) that targeted 18S rRNA and 23S rRNA to detect the DNA of Piroplasma spp. and Anaplasma spp., respectively. The positive samples for 23S rRNA were assayed again by PCR targeting the 16S rRNA. All the blood samples were free from Piroplasma spp. infection. Three camels (2%) were found to be positive for Anaplasma infection through use of PCR that targeted the 23S rRNA gene. There were no significant differences between ages or sexes in the camels that tested positive for Anaplasma. All positive Anaplasma infections were recorded in camels that were infested by ticks. Two Anaplasma sequences for the16S rRNA gene were deposited in GenBank with accession numbers MN882724 and MN882725. They recorded 99.16% and 99.34% similarities (respectively) with KF843825.1 (Candidatus Anaplasma camelii reported in Unizah, Saudi Arabia). Phylogenetic analyses revealed that the two sequences recorded in this study were close to each other; both were located in one cluster with Candidatus Anaplasma camelii isolates that were recorded before in the adjacent areas of Unizah in Saudi Arabia and Iran. In conclusion: two new Anaplasma genotypes close to Candidatus Anaplasma camelii were found in camels in Asir Province, Saudi Arabia for the first time. The camels in this province were found to be free of Piroplasma infection.

Molecular detection and phylogenetic analysis of Leishmania major in stray dogs in Riyadh Province, Saudi Arabia

@#Dogs can act as a reservoir of canine leishmaniasis disease, which is caused by Leishmania species. The study aimed to identify and document the genotype of cutaneous leishmaniasis (CL) in the stray dogs in Riyadh Province using kinetoplast DNA (kDNA) as a target gene by using nested polymerase chain reaction (nPCR). This cross-sectional investigation was conducted over the course of two years, from March 2016 to July 2018, in different districts of Riyadh Province, Saudi Arabia. A total of 237 dogs were examined, only 18 of the dogs were suspected clinically of cutaneous leishmaniasis due to the presence of cutaneous nodules and cutaneous lesion. Biopsy tissue collections were performed and DNA was extracted. CSB2XF and CSB1XR primers were used to amplify the Leishmania kDNA regions. The Leishmania species were detected by specific 13Z and LIR primers by applying nested PCR assay. Nine dogs were found to be positive for Leishmania major. The examined dogs were negative for other Leishmania spp. The phylogenetic analysis and blast results of kDNA showed that the 9 isolates L. major is closely related (99.9%) to the L. major isolate CMG_irfan5, accession number HQ727556.1 from human, Pakistan. This is the first molecular study on dog leishmaniasis from Saudi Arabia confirmed that dogs have a L. major infection. Further epidemiological and molecular investigations are required to study domestic and wild canine infections with L. major and other Leishmania spp in endemic and nonendemic areas of Saudi Arabia as part of leishmaniasis control