Serological Survey of Babesia bovis and Anaplasma marginale in cattle in Tete Province, Mozambique

High infection rate of tick-borne protozoan and rickettsial pathogens of cattle in Malawi and the development of a multiplex PCR for Babesia and Theileria species identification

Malawi has an estimated cattle population of 1,884,803 heads, the indigenous Malawi zebu breed accounts for 91.2%, while the exotic and crossbred accounts for the remaining 8.8%. Although ticks and tick-borne diseases are widespread in Malawi, no molecular study has been conducted to investigate the tick-borne Anaplasmataceae and piroplasms infecting cattle. To provide an insight into the current status of tick-borne pathogens (TBPs) of cattle, a molecular survey was conducted in the central and southern regions of Malawi. A total of 191 cattle of which 132 were Malawi zebu, 44 were Holstein Friesian and 15 were Holstein-Friesian/ Malawi zebu crosses were screened for Anaplasmataceae and piroplasms using the heat shock protein groEL gene and 18S rDNA, respectively. A new 18S rDNA multiplex PCR assay was designed for Babesia and Theileria species identification without sequencing. Overall, 92.3% (n = 177) of the examined animals were infected with at least one TBP. Anaplasmataceae-positive rate was 57.6% (n = 110) while for piroplasms it was 80.1% (n = 153). The detected Anaplasmataceae were Anaplasma bovis 2.6% (n = 5), Anaplasma marginale 24.6% (n = 47), Anaplasma platys-like 13.6% (n = 26), uncharacterized Anaplasma sp. 14.1% (n = 27), and uncharacterized Ehrlichia sp. 16.2% (n = 31). The detected piroplasms were Babesia bigemina 2.6% (n = 5), Theileria mutans 73.8% (n = 141), Theileria parva 33.0% (n = 63), Theileria taurotragi 12.6% (n = 24), and Theileria velifera 53.4% (n = 102). Mixed infection rate was found in 79.6% (n = 152) of the samples analyzed. This study has shown a high burden of TBPs among cattle in Malawi which highlights the need to conceive new methods to control ticks and TBPs in order to improve animal health and productivity. The newly developed multiplex PCR assay would be a useful tool especially in resource limited settings where sequencing is not available and when mixed infections are expected.

Tick-borne diseases in the Union of the Comoros are a hindrance to livestock development: Circulation and associated risk factors

Tick-borne diseases (TBD) occur in many temperate countries and are economically important in most tropical and subtropical areas, affecting dairy and beef cattle, as well as small ruminants. Four major tick-borne diseases have been detected in eastern and southern Africa: East Coast fever (ECF) caused by Theileria parva, Theiler 1904, anaplasmosis caused by either Anaplasma marginale, Theiler 1910, Anaplasma centrale, Theiler 1911, or Anaplasma ovis, Bevan 1912, babesiosis caused by Babesia bovis, Babes 1988 and Babesia bigemina, Smith & Kilborne 1893, and heartwater caused by Ehrlichia ruminantium Cowdry 1925. A cross-sectional survey was undertaken to determine the antibody prevalence of these TBDs and to identify the risk factors for TBD infections in the Union of the Comoros. In 2016 and 2017, 903 individual animal serum samples were collected from 429 separate farms, where the farmers answered individual questionnaires. The antibody prevalence of anaplasmosis, babesiosis (B. bigemina) and heartwater was determined by enzyme-linked immunosorbent assays (ELISA) and the antibody prevalence of ECF was assessed using an immunofluorescence antibody test (IFAT). The relationship between TBD seropositivity and livestock-related variables was assessed by multivariate analyses with standard logistic regression models. The results showed that these four TBDs were present in the Union of the Comoros with a global antibody prevalence of 15% (95% CI [12.7%; 17.3%]) for anaplasmosis, 9.2% (95% CI [6.5%, 11.9%]) for B. bigemina babesiosis, 5.3% (95% CI [3.2%, 7.4%]) for ECF and 4.6% (95% CI [3.2%, 6%]) for heartwater. We compared these findings with the abundance and distribution of several tick species known to be TBD vectors and we found a significant correlation between Rhipicephalus appendiculatus and ECF, and between Amblyomma variegatum and heartwater. We also found that two major variables were significantly correlated with B. bigemina antibody prevalence ("island" and "breeding area"), four variables were significantly correlated with anaplasmosis antibody seroprevalence ("island", "number of cattle per farmer", "number of farmers per village" and "breeding area"), two were significantly correlated with ECF antibody prevalence ("number of farmers in village" and "presence of ticks"), and three were significantly correlated with heartwater ("island", "number of cattle per farmer" and "number of farmers in the village"). Our findings confirmed livestock exposure to the four targeted TBDs of major concern for livestock development. Consequently, raising farmers' awareness and setting up a period of quarantine should be considered a priority.

Diversity of Anaplasma species in cattle in Mozambique

Although species of Anaplasma are highly prevalent Rickettsiales agents in domestic and wild ruminants with a wide distribution worldwide, few studies have been conducted so far to detect and/or investigate the diversity of these agentsin cattle in Mozambique. In the present study, serological and molecular assays were used to investigate the occurrence of Anaplasma spp. in 219 bovines sampled in the districts of Boane, Magude, Matutuíne, Moamba and Namaacha in Maputo, Mozambique. In the iELISA test for detection ofIgG antibodies to A. marginale, 86.3% (189/219) of the samples were positive. In qPCR assays for the gene msp1β for A. marginale and msp2 for A. phagocytophilum, 97.3% (213/219) and 2.7% (6/219) of the animals were positive, respectively. Two different cPCR protocols based on the 16S rRNA gene showed that 100% of the samples were positive for Anaplasma spp. The DNA sequences obtained were phylogenetically related to A. platys, A. phagocytophilum, Candidatus Anaplasma boleense, A. centrale, A. marginale and A. ovis. Phylogenetic inference based on the msp4 and msp5 genes positioned the obtained sequences in the clade of A. marginale, with evidence of occurrence of 8 and 5 different haplotypes for each gene, respectively. Anaplasma sp. phylogenetically associated with A. platys was evidenced in phylogenetic analyzes based on 16S rRNA and groEL genes. It is concluded that a high diversity of species of Anaplasma spp. occurs in cattle in Mozambique.

Prevalence of Anaplasma species in India and the World in dairy animals: A systematic review and meta-analysis

In the present study, the prevalence of Anaplasma species in diary animals from India and World was estimated using meta-analysis. Based on systematic review of studies on Anaplasma species from India [35] and World [66] from 1988 to 2017 and 1978-2017, respectively, using online databases and offline literatures, meta-analysis using meta package in R-Software was done. Prevalence of Anaplasma species in India and World were 11% [95% level, Confidence Interval[CI] 7-16%, Prediction Interval[PI] 1-69%] and 39% [95% level, CI 30-49%, PI 2-95%], and these were obtained using 31,117 and 46,365 samples, respectively. Period-wise analysis revealed high Anaplasma species prevalence before 2011 for India and the World than from 2011 through 2017. Zone-wise prevalence indicated high prevalence in Central zone [61%] and low in West and South zones [6%] in India, and continent-wise, it was high in South America [82%]. The studies used methods including blood smear examination, serology and nucleic acid-based techniques and revealed high prevalence in serology for India [34%] and World [46%], low prevalence by blood smear for India [7%] and World [21%], but higher sensitivity using nucleic acid-based techniques. Species-wise indicated higher prevalence in cattle [12%] than buffaloes [2%] in India. Prevalence was lower in India compared to the World and higher in South America. Overall, anaplasmosis causes low productivity in dairy animals and economic loss to dairy farmers. Hence, there is a need to control Anaplasma infections in high risk areas by adopting effective therapeutic and preventive measures so as to improve the economic benefits in dairy farming.

Anaplasma infection prevalence in beef and dairy cattle in the south east region of Botswana

Infection of cattle by the tick-borne intra-erythrocytic bacteria of the genus Anaplasma occurs worldwide. Nevertheless, prevalence rates in specific regions are still required to inform cattle farming management decisions. A study was carried out to determine Anaplasma infection prevalence in beef and dairy cattle in the south east region of Botswana. Two methods were used: competitive inhibition enzyme-linked immune-sorbent assay (cELISA) and conventional polymerase chain reaction (PCR). A total of 429 cattle consisting 207 beef and 222 dairy animals were sampled and tested. The prevalence was 91% and 31% by cELISA and PCR, respectively. A Z test revealed a statistical difference between the point prevalence as determined by cELISA compared to PCR (p=0). There was no statistical difference between the point prevalence of Anaplasma infection as determined by cELISA (p=0.45) between beef and dairy cattle. But there was a significant difference (p=0.001) between the animals by PCR with the prevalence in beef cattle nearly double that in dairy cattle. Individual herd prevalence ranged from 79% to 100% by cELISA, and 0 to 100% by PCR. Though not statistically significant sero-prevalence in both beef and dairy animals tended to be higher in urban/peri-urban areas compared to rural areas. The cELISA mean percentage inhibition (PI) for all cattle was found to be 58.6 (95% CI: 56.8-60.4). There was no statistically significant difference between the mean PI of sera from beef cattle (56.4 (95% CI: 54.1-58.7)) as compared to dairy cattle (60.7 (95%CI: 58.0-63.3)). However, there was a tendency towards statistical significance with beef animals having a lower PI value than dairy animals. Anaplasma infection was endemic in cattle in the south east region of Botswana with similar infection in beef and dairy animals. Further research should be done to identify the strains prevalent in the cattle herds.

Alpha proteobacteria of genusAnaplasma(Rickettsiales: Anaplasmataceae): Epidemiology and characteristics ofAnaplasmaspecies related to veterinary and public health importance

TheAnaplasmaspecies are important globally distributed tick-transmitted bacteria of veterinary and public health importance. These pathogens, cause anaplasmosis in domestic and wild animal species including humans.Rhipicephalus, Ixodes, DermacentorandAmblyommagenera of ticks are the important vectors ofAnaplasma.Acute anaplasmosis is usually diagnosed upon blood smear examination followed by antibodies and nucleic acid detection. All age groups are susceptible but prevalence increases with age. Serological cross-reactivity is one of the important issues amongAnaplasmaspecies. They co-exist and concurrent infections occur in animals and ticks in same geographic area. These are closely related bacteria and share various common attributes which should be considered while developing vaccines and diagnostic assays. Movement of susceptible animals from non-endemic to endemic regions is the major risk factor of bovine/ovine anaplasmosis and tick-borne fever. Tetracyclines are currently available drugs for clearance of infection and treatment in humans and animals. Worldwide vaccine is not yet available. Identification, elimination of reservoirs, vector control (chemical and biological), endemic stability, habitat modification, rearing of tick resistant breeds, chemotherapy and tick vaccination are major control measures of animal anaplasmosis. Identification of reservoirs and minimizing the high-risk tick exposure activities are important control strategies for human granulocytic anaplasmosis.

Seroprevalence of IgG antibodies against Anaplasma marginale in cattle from south Mozambique

The current study aimed to investigate the seroprevalence of IgG antibodies to Anaplasma marginale in cattle from Maputo, Gaza and Inhambane provinces, south Mozambique. A total of 809 serum samples from cattle were obtained and tested by indirect enzyme-linked immunosorbent assay (i-ELISA). The chi-square test at 5% significance was used to assess the association between seroprevalence and the variables gender, age and geographic origin of animals. The overall seropositivity was 76.5% (n = 619) and anti-A. marginale antibodies were detected in 89.1% (n = 156), 68.4% (n = 308) and 84.2% (n = 155) of the animals in the provinces of Maputo, Gaza and Inhambane, respectively. A significant association (p < 0.05) was found with the geographic origin of the animals, while sex had no significant relationship. The frequencies of seropositive in the age groups were 63.2% (n = 72), 80.0% (n = 92), 83.1% (n = 98) and 77.3% (n = 357) for animals <12; >12 and ≤24; >24 and ≤36; >36 months, respectively. These results indicate that in southern Mozambique there are areas of enzootic stability to A. marginale. Thus, epidemiological monitoring is required to monitor the immune status of animals in the region.

Expression and characterization of the Babesia bigemina cysteine protease BbiCPL1

BbiCPL1 was the first papain-like cysteine protease from a piroplasm to be identified with proteolytic activity. Here we report the improved production of the active recombinant enzyme, and the biochemical characterization of this potential drug target. BbiCPL1 showed characteristic properties of its class, including hydrolysis of papain-family peptide substrates, an acidic pH optimum, requirement of a reducing environment for maximum activity, and inhibition by standard cysteine protease inhibitors such as E-64, leupeptin, ALLN and cystatin. The optimum pH for the protease activity against peptide substrates was 5.5, but enzymatic activity was observed between pH 4.0 and pH 9.0. At slightly basic pH 7.5, BbiCPL1 maintained 83% of maximum activity, suggesting a role in cytosol environment.

Serological survey of Babesia bovis and Babesia bigemina in cattle in South Africa

A total of 719 serum samples collected from clinically healthy cattle from eight provinces located in different districts of South Africa were examined by the indirect enzyme-linked immunosorbent assay (ELISA) and the standard indirect fluorescent antibody test (IFAT) to determine the serological prevalence of Babesia bovis and Babesia bigemina. The results showed that 35.3% and 39.7% of cattle were positive for B. bovis and 30% and 36.5% were positive for B. bigemina antibodies on ELISA and IFAT, respectively. Mixed infections were detected in 18.2% and 26.3% of the samples using ELISA and IFAT, respectively. Consequently, the ELISAs with recombinant B. bovis spherical body protein-4 (BbSBP-4) and B. bigemina C-terminal rhoptry-associated protein-1 (BbigRAP-1/CT) were proven to be highly reliable in the serological diagnoses of bovine babesiosis in South African cattle, as evidenced by the significant concordance rates when the results were compared to those of IFAT. Moreover, the serological prevalence was significantly different among the tested provinces, in which the ranges exhibited between 15% and 73% for B. bovis infection and between 13% and 54% for B. bigemina infection. High sero-positive rates were present in Mpumalanga and KwaZulu-Natal provinces, while the lowest rate was in the North West province. Our data provide important information regarding the current seroprevalence of bovine babesiosis in South Africa, which might be beneficial in developing rational strategies for disease control and management.

Molecular detection ofBabesiaspp. and other haemoparasitic infections of cattle in Maputo Province, Mozambique

Molecular detection ofBabesiaspecies in apparently healthy cattle within an endemic region was carried out in order to determine the prevalence of carriers and the geographical distribution ofBabesia bigeminaandBabesia bovisin Maputo Province, Mozambique. Samples from 477 animals at 5 localities were analysed using 2 techniques, the semi-nested hot-start PCR and the reverse line blot (RLB) assay. With the semi-nested hot-start PCR, detection ofB. bigeminaranged between 30% and 89%, and ofB. bovisbetween 27% and 83%. The RLB assay was comparatively less sensitive in this study and detection ofB. bovisranged from 0% to 17%, andB. bigeminawas not detected at all by this technique. Analysis of new sequences of the 18S rRNA gene revealed that the currentB. bigeminaRLB probe is not specific for the identification of isolates in Mozambique. The RLB assay, however, resulted in the detection of 8 other haemoparasite species belonging to the generaBabesia,Theileria,AnaplasmaandEhrlichia. 18S rRNA gene sequences from theTheileriaspp. were identified, and a phylogenic tree constructed with these sequences yielded a heterogeneousT. mutans-like group. In conclusion, infection withB. bigeminaandB. bovisis endemic in Maputo Province, but rates of transmission vary. Furthermore, mixed infections with the haemoparasites responsible for several tick-borne diseases in cattle are common in Mozambique.

A comparison of seroprevalence and risk factors for Theileria parva and T. mutans in smallholder dairy cattle in the Tanga and Iringa regions of Tanzania

A cross sectional serological survey was carried out in two geographical small-scale dairying areas of Tanzania to determine the distribution and prevalence and to quantify risk factors for Theileria parva and T. mutans during the period January to April 1999. The prevalence of serum antibodies to these two Theileria parasites was determined using an indirect enzyme-linked immunosorbent assay (ELISA) technique. The results suggest that the parasites are widely distributed through out the two study sites and seroprevalence of 23% and 48% for T. parva were obtained for Tanga and Iringa regions, respectively. Seroprevalence of T. mutans ranged from 17% in the Tanga region to 40% in the Iringa region. Farm and animal data were collected and analysed by multiple logistic regression models to explore the risk factors associated with seroprevalence to T. parva and T. mutans pathogens. In both regions, seroprevalence for the two Theileria spp. pathogens increased significantly with age. Pasture grazed animals were more likely to be seropositive than those that were zero-grazed. Among individual animal characteristics, seropositivity was higher in cash-bought and charity gifted animals compared to cattle obtained using a formal credit agreement. Further studies on the relative role of risk factors for theileriosis found in this study may assist in the development of an effective control package.