RESUMO
Introduction: The two-humped Bactrian camel (Camelus bactrianus) is a large, even-toed ungulate native to the steppes of Central Asia. Domestic Bactrian camels are economically important in Mongolia and other Central Asian countries. These animals are used for transport, milk and meat production, and camel racing which is a great culture of nomads. Eimeriosis, also known as coccidiosis, is considered as an economically important parasitic diseases in Bactrian camels. There is still considerable lack of data concerning the spectrum of monoxenous Eimeria species, their epizootiology as well as their precise life cycles in Bactrian camels. This study was performed to determine the prevalence of Eimeria species in camelids from southern part of Mongolia. Methods: A total of 536 fresh camel fecal samples (n = 536) collected from herds located in five different Aimags (provinces) of Mongolia were examined. Eimeria spp. oocysts were isolated using the sugar flotation technique, and after sporulation, oocysts were identified by morphometric evaluation. Results: We identified the most common Eimeria species infecting Mongolian Bactrian camels: Eimeria cameli (22.3%), Eimeria rajasthani (37.3%) and Eimeria dromedarii (27.7%). Interestingly, mixed infections were detected in 24.8% (n = 133) of the samples, while 39.0% (n = 209) were negative for coccidian stages. To investigate the immunogenetic response of the Mongolian Bactrian camels to Eimeria spp. infection, we screened the genetic diversity in a functional important immune response gene of the major histocompatibility complex (MHC). We detected two polymorphic sites in the MHC class II DRA exon 2, which translated into one non-synonymous and one synonymous amino acid (aa) change. Discussion: The resulting aa alleles were not significantly associated with any of the three detected Eimeria species infections, nor could we show heterozygote advantage in non-infected Mongolian Bactrian camels. Further investigations on molecular epidemiology, in vitro culture, pathogenicity and host-parasite interactions will be necessary to better understand the impact of eimeriosis in Bactrian camels.
RESUMO
Cameline filarosis is an important parasitic disease having an economic impact on the camel industry around the world. However, there has been no study on filarosis in Bactrian camels of Mongolia. Therefore, the aim of the present study was to detect and identify microfilariae of Deraiophoronema evansi (D. evansi) in Bactrian camels from three provinces, located in southern and southwestern Mongolia. Blood samples were obtained from 400 healthy two-humped camels of different ages and both sexes. All blood samples were analysed using a variety of diagnostic techniques. Microfilariae were detected in 30 Bactrian camels (7.5%) by the Knott technique, while 13 Bactrian camels (3.3%) tested positive in a direct smear test. D. evansi was detected in 18 Bactrian camels (4.5%) by PCR assay. Prevalence was shown to be high among Bactrian camels in the age group up to 5 years, while the lowest positive results were obtained for Bactrian camels in the 5-10-year age group and the over 10-year age group. To confirm the morphological identification, D. evansi-COI gene sequences were subjected to phylogenetic analyses. The D. evansi-COI gene sequences from Mongolian two-humped camels were identical to sequences from Iranian one-humped camels and were clustered together with these sequences in the phylogeny. This is the first report of molecular detection and identification of microfilariae of D. evansi in Bactrian camels of Mongolia.
