First Molecular Evidence for the Presence of Anaplasma phagocytophilum in Naturally Infected Small Ruminants in Tunisia, and Confirmation of Anaplasma ovis Endemicity

Abstract

Anaplasma species are obligate intracellular rickettsial vector-borne pathogens that impose economic constraints on animal breeders and threaten human health. Anaplasma ovis and Anaplasma phagocytophilum infect sheep and goats worldwide. A duplex PCR targeting the msp2 and msp4 genes of A. phagocytophilum and A. ovis, respectively, was developed to analyze the field blood samples collected from sheep and goats. A total of 263 apparently healthy small ruminants from 16 randomly selected flocks situated in 3 bioclimatic zones in Tunisia were analyzed for Anaplasma infections. Anaplasma spp. was detected in 78.3% (95% confidence interval (CI): 72.8–83.1) of the analyzed animals. The prevalence of A. ovis in sheep (80.4%) and goats (70.3%) was higher than that of A. phagocytophilum (7.0% in sheep and 1.6% in goats). Using an inexpensive, specific, and rapid duplex PCR assay, we provide, to the best of our knowledge, the first molecular evidence for the presence of A. phagocytophilum in small ruminants in Tunisia. A. phagocytophilum generally presented as a co-infection with A. ovis. This study provides important data to understand the epidemiology of anaplasmosis in small ruminants, and highlights the risk of contracting the infection upon tick exposure.

Molecular prevalence and phylogeny of Anaplasma marginale, Anaplasma ovis and Theileria ovis in goats and sheep enrolled from a hill station in Punjab, Pakistan

“…In a recent investigation from Tunisia, El Hamdi et al [28] have reported that 22.6% of lambs and the entire enrolled ewes (100%) were found infected with A. ovis. In another report from Tunisia, it was reported that prevalence of A. ovis in sheep was 80.4% and the bacterium was detected in 70.3% of enrolled goats [5]. In addition, the prevalence of A. ovis was reported to be 69% in small ruminants of Mongolia [29], 54.5% in China [30], 34.2% in central and Western Kenya [31], 29.7% in Turkey [32], 20.8% in Iran [26], 14.8% in Bangladesh [33] and 1.5% in Thailand [34].…”

“…[4]. Anaplasma ovis was first identified and reported in 1912 and since then its presence has been frequently reported from Asia, Africa, United States and Europe [5]. The acute phase of A. ovis infection results in fever, severe anemia, weight loss, lower milk production, abortion and jaundice in host animals [6].…”

Anaplasma Species in Africa—A Century of Discovery: A Review on Molecular Epidemiology, Genetic Diversity, and Control

“…In Africa, A. ovis has frequently been detected in ticks of the Rhipicephalus genus [ 10 , 17 , 22 , 26 , 54 , 117 ] and less frequently in Amblyomma ticks [ 26 , 109 ]. Factors that impact the prevalence of A. ovis in small ruminants are suggested to include the sampling technique used, presence of tick vectors, livestock management practices, the climate and ecology of the study area and the immune status and vulnerability of the host animals [ 118 ]. Genetic markers used in the detection and characterization of A. ovis in animals and ticks in Africa include the 16S rRNA, 23S rRNA, msp4 , gltA , msp1a and groEL genes, with a majority of the studies using the msp4 gene [ 9 , 10 , 17 , 54 , 67 , 90 , 94 , 109 , 119 , 120 , 121 , 122 , 123 ] ( Table 1 ).…”

The Scenario of Ticks and Tick-Borne Pathogens of Sheep on a Mediterranean Island

“…Tick-borne pathogens can cause significant losses in livestock reared outdoors in extensive systems, such as sheep [6]. Specifically, for the Mediterranean region, there are several surveys reporting high endemicity of the pathogens of the genus Anaplasma spp.such as A. phagocytophilum, A. ovis, and A. capra-in sheep; however, their pathogenicity is not fully described [2,[7][8][9][10][11][12]. In Greece, sheep farming is particularly important (with a national flock of 8,427,196 animals-Hellenic Statistical Authority, https://www.statistics.…”