Detection of bovine babesiosis in Mozambique by a novel seminested hot-start PCR method

Molecular detection and phylogenetic analysis of tick-borne pathogens in cattle from southern Malawi

INTRODUCTION

Tick-borne diseases (TBDs) pose a major hindrance to livestock production in countries with limited resources. Effective prevention and management of TBDs require a thorough understanding of disease vectors and pathogens. However, there is limited information on studies of bovine tick-borne pathogens (TBPs) using molecular methods in Malawi. This study aimed to detect TBPs of cattle populations in southern Malawi, which has the largest cattle population in the country.

METHODOLOGY

A total of 220 blood samples from apparently healthy cattle were collected in six districts, and were screened for selected TBPs using polymerase chain reaction (PCR).

RESULTS

The overall detection rate of TBPs was 72.3%. Among the detected pathogens, Babesia bigemina had the highest detection rate (34.5%), followed by Anaplasma marginale (23.2%), Anaplasma phagocytophilum (22.3%), Theileria taurotragi (22.3%), Theileria parva (15.5%), Anaplasma bovis (9.6%), Babesia bovis (7.3%), Theileria mutans (4.1%), and Babesia naoakii (2.7%). Among the positive samples, 64.2% were found to be co-infected with two or more TBPs, with the highest number of seven pathogens detected in a single sample. The study documents the existence of A. phagocytophilum, B. bovis, and B. naoakii in Malawian cattle for the first time.

CONCLUSION

The findings herein demonstrate a significant burden of TBPs on cattle in Malawi, which gives a challenge in combating TBDs. The high TBP burden, along with the high co-infection frequencies in Malawian cattle necessitates the urgency to implement effective control strategies to enhance cattle production in the country.

Serological and molecular detection of neurocysticercosis among epileptic patients in Nagpur, Maharashtra state (India)

Neurocysticercosis (NCC), one of the most important neuroparasitic diseases in humans, is caused by Cysticercus cellulosae, the metacestode stage of digenetic zoonotic cestode Taenia solium. The present study aims at the detection of anti-cysticercus antibodies in the sera of epileptic patients (n=26) visiting a tertiary care hospital in Nagpur, Maharashtra state, India, by an in-house developed indirect IgG-ELISA and enzyme-linked immunoelectro transfer blot (EITB) assay using different antigens (namely, Whole Cyst Antigen (WCA), Cystic Fluid Antigen (CFA), Scolex Antigen (SA), Excretory-Secretory Antigen (ESA) and Membrane-Body Antigen (MBA)) prepared from T. solium metacestodes to find out the status of NCC. An attempt has also been made for molecular detection of NCC from blood samples of those patients by Polymerase Chain Reaction (PCR) assay targeted at large subunit rRNA gene of T. solium. The IgG ELISA level of anti-cysticercus antibodies against WCA, CFA, SA, ESA and MBA antigens were as follows: 19.23 %, 23.07 %, 38.46 %, 30.76 % and 15.38 %. The seroreactivity to CFA, SA and ESA was found in equal proportions in patients with ring-enhancing lesions. In the EITB assay, the lower and medium molecular weight protein bands of SA and ESA were immunodominant compared to the higher WCA and CFA peptides. PCR positivity could be observed in 34.6 % (9/26) of the patients under study. It is the first report of detecting NCC among epileptic patients of the Nagpur region of Maharashtra state in India using serological and molecular tools.

Epidemiology of Ticks and Tick-Borne Pathogens in Domestic Ruminants across Southern African Development Community (SADC) Region from 1980 until 2021: A Systematic Review and Meta-Analysis

Ticks are hematophagous ectoparasites that are capable of infesting a wide range of mammals, including domestic animals, ruminants, wildlife, and humans across the world, and they transmit disease-causing pathogens. Numerous individual epidemiological studies have been conducted on the distribution and prevalence of ticks and tick-borne diseases (TBDs) in the Southern African Developing Community (SADC) region, but no effort has been undertaken to synchronize findings, which would be helpful in the implementation of consolidated tick control measures. With the aim of generating consolidated pooled prevalence estimates of ticks and TBDs in the SADC region, we performed a systematic review and meta-analysis of published articles using the PRISMA 2020 guidelines. A deep search was performed on five electronic databases, namely, PubMed, ScienceDirect, Google Scholar, AJOL, and Springer Link. Of the 347 articles identified, only 61 of the articles were eligible for inclusion. In total, 18,355 tick specimens were collected, belonging to the genera Amblyomma, Haemaphysalis, Hyalomma, and Rhipicephalus (including Boophilus) across several countries, including South Africa (n = 8), Tanzania (n = 3), Zambia (n = 2), Zimbabwe (n = 2), Madagascar (n = 2), Angola (n = 2), Mozambique (n = 1), and Comoros (n = 1). The overall pooled prevalence estimate (PPE) of TBPs in livestock was 52.2%, with the highest PPE in cattle [51.2%], followed by sheep [45.4%], and goats [29.9%]. For bacteria-like and rickettsial TBPs, Anaplasma marginale had the highest PPE of 45.9%, followed by A. centrale [14.7%], A. phagocytophilum [2.52%], and A. bovis [0.88%], whilst Ehrlichia ruminantium had a PPE of 4.2%. For piroplasmids, Babesia bigemina and B. bovis had PPEs of 20.8% and 20.3%, respectively. Theileria velifera had the highest PPE of 43.0%, followed by T. mutans [29.1%], T. parva [25.0%], and other Theileria spp. [14.06%]. Findings from this study suggest the need for a consolidated scientific approach in the investigation of ticks, TBPs, and TBDs in the whole SADC region, as most of the TBDs are transboundary and require a regional control strategy.

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.

The molecular prevalence, distribution and risk factors associated with Babesia bigemina infection in Peninsular Malaysia

Babesia bigemina is a tick-borne protozoan that affects cattle in almost all regions of the world. Despite its importance, there is no report of its prevalence in cattle using molecular detection methods in Peninsular Malaysia. This study describes the prevalence, distribution, and risk factors associated with B. bigemina infection using molecular diagnostic methods. Also, the species of ticks infesting cattle and the attitude of cattle farmers towards tick control in Peninsular Malaysia were studied. Blood samples were collected from 1045 cattle from 43 herds throughout the country, and were subjected to molecular studies to detect B. bigemina. Tick samples for entomological studies were also collected and identified. Epidemiological information of each cattle and farm were obtained using a well-structured questionnaire containing open-ended and closed-ended questions. Data were statistically analyzed using Univariate and Multivariate models. The 211-base pair of AMA-1 gene of B. bigemina was amplified and confirmed in 30.5 % (319/1045; 95 % CI = 27.8-33.4) of the sampled population, with the haemoprotozoan detected in all the sampled herds. Breed, age, physiological status, management type, rate of de-ticking, and closeness to human settlement were the risk factors significantly (p < 0.05) associated with the prevalence of B. bigemina in cattle. Rhipicephalus (Boophilus) microplus and Haemaphysalis bispinosa were the species of ticks collected from cattle, with the former been more prevalent. A large number of cattle farmers (12/43; 28 %) do not control ticks in their herds. The findings of this study will create baseline data on the epidemiology of the haemoprotozoan and control patterns of its tick vectors that will guide the government in enacting policies that will improve food security and the economy of the nation.

Pentaplex PCR assay for rapid differential detection of Babesia bigemina, Theileria annulata, Anaplasma marginale and Trypanosoma evansi in cattle

A multiplex PCR (mPCR) assay for simultaneous detection and differentiation of four major haemoparasites in crossbred cattle was established using parasite specific genomic DNA and four sets of primer pairs targeting AMA-1, Tams1, MSP5 and VSG genes of Babesia bigemina, Theileria annulata, Anaplasma marginale and Trypanosoma evansi generating precise amplicons of 448, 156, 382 and 110 bp, respectively. An internal amplification control, 202 bp bovine β-casein gene fragment, was simultaneously amplified with four target genes to avoid false-negative results. The sensitivity of mPCR was 3.44 × 10², 5.9 × 10³, 2.88 × 10² and 3.3 × 10³ copies for B. bigemina, T. annulata, A. marginale and T. evansi, respectively. mPCR of cattle clinical samples (n = 516), suspected for haemoparasites, revealed single haemoparasitic infection in 279 (54.06%) cases, whereas mixed infection was recorded in 54 (10.46%) samples. In clinical samples, coinfection with T. annulata and A. marginale was the most common. The findings of mPCR were consistent with uniplex PCR under field conditions except for subtle variations in A. marginale infection. Overall, the mPCR assay represents an economical, reproducible and robust diagnostic tool for concurrent detection of cattle haemoparasites and large scale epidemiological studies.

Molecular detection and characterization of Ehrlichia ruminantium from cattle in Mozambique

Heartwater caused by Ehrlichia ruminantiumis a disease of domestic and wild ruminants and one of the most economically important tick-borne diseases in Africa. The present study aimed to investigate the occurrence and genetic diversity of E. ruminantium in blood samples from 210 cattle sampled in five districts of Maputo Province, Mozambique. DNA blood samples were initially submitted to PCR assays targeting E. ruminantium pCS20 gene fragments. Additionally, in order to assess the genetic diversity of E. ruminantium, the positive samples were submitted to a PCR assay targeting the E. ruminantium map1 gene. Finally, the amplicons were sequenced and phylogenetic position was inferred using the Maximum Likelihood method. PCR results revealed that the overall prevalence in Maputo Province was 15% of the animals sampled. E. ruminantium map1 sequences showed not to be conserved. In the phylogenetic analysis, E. ruminantium map1 genotypes were positioned into multiple-clades. This study provides information on the prevalence and genetic diversity of E. ruminantium in five localities of Maputo Province. The future immune control strategies against local E. ruminantium must be designed in the light of the genetic diversity of this parasite.

Distribution of Orientia tsutsugamushi in rodents and mites collected from Central India

Orientia tsutsugamushi, the causative agent of scrub typhus, is an obligate intracytosolic bacterium transmitted among humans and small mammals by some species of larval trombiculid mites (chiggers). It has been recognized as a pathogen of major public health concern in the Asia-Pacific region. As disease is considered as a neglected, there exists a gap in our knowledge of the disease with regard to the sporadic epidemiologic data in endemic areas. The purpose of the study was to find out the vector as well as pathogen distribution in rodents present in the scrub typhus-reported areas in central India. We studied the seasonal variations of occurrence in O. tsutsugamushi in rodents and mites by molecular detection targeting the 56-kDa and 47-kDa genes. Rodent and mite samples were collected during December 2015 to July 2017. A total of 127 samples from rodents, seven pools of mites, and four pools of fleas were collected and processed for DNA isolation. Nested PCRs targeting the 56-kDa and 47-kDa surface antigen genes were performed. In addition, quantification of bacterial load was done by qPCR targeting the 47-kDa gene. During the pre-monsoon season, O. tsutsugamushi was detected in 12% and 10% samples employing the 56-kDa and 47-kDa nested PCRs, respectively, whereas, during post-monsoon season, the respective detection rates were 13.33% and 26.66%. This study predicted a bimodal pattern during the months of pre-monsoon and post-monsoon season with a peak in post-monsoon. Thus, the impact of season on the perpetuation of O. tsutsugamushi in the host was observed.

PCR detection of Ehrlichia ruminantium and Babesia bigemina in cattle from Kwara State, Nigeria: unexpected absence of infection

Ticks and tick-borne diseases (TBDs) continue to pose an insidious and ever-present threat to livestock and livelihoods across the globe. Two of the most significant TBDs of cattle in Africa are heartwater and babesioisis, caused by Ehrlichia ruminantium and Babesia bigemina respectively. Both pathogens are endemic in Nigeria. However, to date, little data has been published regarding the number of cattle infected. In this study, blood samples were collected from cattle of the Kwara State, north-central Nigeria. Probe-based quantitative PCR (qPCR) and semi-nested PCR were used to investigate the presence of both pathogens, respectively. Our study found all samples (n = 157) to be surprisingly negative for both B. bigemina and E. ruminantium. These results contribute new information on the current burden of these two pathogens in Kwara State and may be helpful in informing more effective targeting of control strategies in Nigeria.

Molecular detection of pathogens in ticks infesting cattle in Nampula province, Mozambique

Ticks are ectoparasites that can act as vectors of a large number of pathogens in wild and domestic animals, pets, and occasionally humans. The global threat of emerging or re-emerging tick-borne diseases supports the need for research focused in the zoonotic transmission, especially in countries like Mozambique where rural populations are in close contact with domestic animals. The present study aims to: (1) identify tick species infesting cattle from Monapo and Nacala Porto, districts of Nampula province, Mozambique; and (2) investigate the presence of pathogens in the collected ticks. A total of 646 ticks were collected from cattle and morphologically identified as Amblyomma variegatum, Rhipicephalus microplus, and R. evertsi evertsi. For convenience, 72 A. variegatum and 15 R. microplus from Monapo, and 30 A. variegatum from Nacala Porto were screened for the presence of the selected pathogens: Rickettsia spp. (A. variegatum), and Babesia/Theileria spp. and Anaplasma/Ehrlichia spp. (R. microplus). Rickettsia africae was detected in four of the 72 A. variegatum collected in Monapo (5.6%). Additionally, one R. microplus tick (6.7%) was positive for Theileria velifera, one positive for Colpodella spp., one positive for Candidatus Midichloria mitochondrii, and another one positive for Anaplasma ovis. Using the present approach, no microorganisms were detected in tick samples from Nacala Porto. These findings expand our knowledge about the repertoire of tick-borne microorganisms in ticks in Nampula province, Mozambique.

Prevalence of tick-borne haemoparasites in small ruminants in Turkey and diagnostic sensitivity of single-PCR and RLB

Background

Tick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these diseases threaten livestock production and some also represent a concern to human public health. The primary aim of this study was to determine the prevalence of the above-mentioned pathogens in a large number of blood samples (n = 1979) collected from sheep (n = 1727) and goats (n = 252) in Turkey. A secondary aim was to assess the diagnostic sensitivity of a number of species-specific polymerase chain reaction (PCR) tests and the reverse line blotting (RLB) assay. DNA samples were screened using species-specific PCR for the presence of Theileria ovis, Theileria sp. MK, T. lestoquardi, T. uilenbergi, T. luwenshuni, Babesia ovis, Anaplasma ovis and A. phagocytophilum while RLB was undertaken to test for the presence of all known Theileria, Babesia, Anaplasma and Ehrlichia species. The diagnostic sensitivity of these two approaches was then compared in terms of their ability to detect single species and mixed infections.

Results

Overall, 84 and 74.43% of the small ruminants sampled were identified as hosting one or more pathogen(s) by species-specific PCR and RLB respectively. The presence of Theileria sp. OT1, T. luwenshuni and T. uilenbergi in Turkey was revealed for the first time while the presence of Babesia motasi, B. crassa and T. separata in Turkish small ruminants was confirmed using molecular methods. A high prevalence of mixed infection was evident, with PCR and RLB approaches indicating that 52.24 and 35.42% of animals were co-infected with multiple species, respectively. More than 80% of the mixed infections contained T. ovis and/or A. ovis. The RLB approach was found to be capable of detecting mixed infections with species such as Theileria sp. OT1, Theileria sp. OT3, T. separata, B. crassa and Babesia spp.

Conclusion

The results indicated that pathogens causing TBHDs are highly prevalent in sheep and goats in Turkey. The diagnostic sensitivity of species-specific single PCR was generally higher than that of RLB. However, the latter approach was still capable of identifying a high proportion of individuals containing mixed-species infections. The use of species-specific single PCR is recommended to accurately estimate pathogen prevalence and to identify co-infected hosts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2151-3) contains supplementary material, which is available to authorized users.

Molecular diagnosis of the tick-borne pathogen Anaplasma marginale in cattle blood samples from Nigeria using qPCR

Tick-borne diseases (TBDs) are some of the most important animal health and management problems in Africa, including Nigeria. This study aims to determine the prevalence of an important TBD, anaplasmosis, in a North-central region of Nigeria. Blood samples were collected from cattle and stored on Whatman FTA^® cards. Information on village, age and sex associated with each cattle was also recorded. The packed red blood cell volume (PCV) for each blood sample was determined. After DNA extraction, pathogen presence was evaluated by TaqMan^® based qPCR of which 75.9 % of the cattle tested positive for Anaplasma marginale. Statistical analysis revealed that the presence of A. marginale infection differed significantly between cattle age groups. However, there was no significant difference in the prevalence of this pathogen between the sexes or among cattle grouped by PCV level. Finally, using a highly sensitive molecular method our pioneer study contributes to the improvement of the current knowledge regarding tick-borne pathogens that seriously affect animal health in specific areas of Nigeria.

Comparison between conventional and molecular methods for diagnosis of bovine babesiosis (Babesia bovis infection) in tick infested cattle in upper Egypt

Ticks and tick-borne diseases are the main problems affecting the livestock production in Egypt. Bovine babesiosis has adverse effects on the animal health and production. A comparison of Giemsa stained blood smears, polymerase chain reaction (PCR) and nested PCR (nPCR) assays for detection of Babesia bovis infection in Egyptian Baladi cattle (Bos taurus) in reference to reverse line blot was carried out. The sensitivity of PCR and nested PCR (nPCR) assays were 65 and 100 % respectively. Giemsa stained blood smears showed the lowest sensitivity (30 %). According to these results using of PCR and nPCR target for B. bovis, [BBOV-IV005650 (BV5650)] gene are suitable for diagnosis of B. bovis infection. The 18Ss rRNA partial sequence confirmed that all the positive samples were Babesia bovis and all of them were deposited in the GenBank databases (Accession No: KM455548, KM455549 and KM455550).

Detection of Babesia bovis in blood samples and its effect on the hematological and serum biochemical profile in large ruminants from Southern Punjab

OBJECTIVE

To determine the presence of Babesia bovis (B. bovis) in large ruminants in southern Punjab and its effect on hematological and serum biochemical profile of host animals.

METHODS

Blood samples were collected from 144 large ruminants, including 105 cattle and 39 buffaloes, from six districts in southern Punjab including Multan, Layyah, Muzaffar Garh, Bhakar, Bahawalnagar and Vehari. Data on the characteristics of animals and herds were collected through questionnaires. Different blood (hemoglobin, glucose) and serum (ALT, AST, LDH, cholesterol) parameters of calves and cattle were measured and compared between parasite positive and negative samples to demonstrate the effect of B. bovis on the blood and serological profile of infected animals.

RESULTS

27 out of 144 animals, from 5 out of 6 sampling districts, produced the 541-bp fragment specific for B. bovis. Age of animals (P=0.02), presence of ticks on animals (P=0.04) and presence of ticks on dogs associated with herds (P=0.5) were among the major risk factors involved in the spread of bovine babesiosis in the study area. ALT concentrations were the only serum biochemical values that significantly varied between parasite positive and negative cattle.

CONCLUSIONS

: This study has reported for the first time the presence of B. bovis in large ruminant and the results can lead to the prevention of babesiosis in the region to increase the livestock output.

Nested PCR detection and phylogenetic analysis of Babesia bovis and Babesia bigemina in cattle from Peri-urban localities in Gauteng Province, South Africa

Babesia bovis and Babesia bigemina are tick-borne hemoparasites causing babesiosis in cattle worldwide. This study was aimed at providing information about the occurrence and geographical distribution of B. bovis and B. bigemina species in cattle from Gauteng province, South Africa. A total of 268 blood samples collected from apparently healthy animals in 14 different peri-urban localities were tested using previously established nested PCR assays for the detection of B. bovis and B. bigemina species-specific genes encoding rhoptry-associated protein 1 (RAP-1) and SpeI-AvaI restriction fragment, respectively. Nested PCR assays revealed that the overall prevalence was 35.5% (95% confidence interval [CI]=± 5.73) and 76.1% (95% CI=± 5.11) for B. bovis and B. bigemina, respectively. PCR results were corroborated by sequencing amplicons of randomly selected samples. The neighbor-joining trees were constructed to study the phylogenetic relationship between B. bovis and B. bigemina sequences of randomly selected isolates. Analysis of phylogram inferred with B. bovis RAP-1 sequences indicated a close relationship between our isolates and GenBank strains. On the other hand, a tree constructed with B. bigemina gp45 sequences revealed a high degree of polymorphism among the B. bigemina isolates investigated in this study. Taken together, the results presented in this work indicate the high incidence of Babesia parasites in cattle from previously uncharacterised peri-urban areas of the Gauteng province. These findings suggest that effective preventative and control measures are essential to curtail the spread of Babesia infections among cattle populations in Gauteng.

Molecular diagnosis and phylogenetic analysis of Babesia bigemina and Babesia bovis hemoparasites from cattle in South Africa

Background

Babesia parasites, mainly Babesia bovis and B. bigemina, are tick-borne hemoparasites inducing bovine babesiosis in cattle globally. The clinical signs of the disease include, among others, anemia, fever and hemoglobinuria. Babesiosis is known to occur in tropical and subtropical regions of the world. In this study, we aim to provide information about the occurrence and phylogenetic relationship of B. bigemina and B. bovis species in cattle from different locations in nine provinces of South Africa.

A total of 430 blood samples were randomly collected from apparently healthy cattle. These samples were genetically tested for Babesia parasitic infections using nested PCR assays with species-specific primers.

Results

Nested PCR assays with Group I primer sets revealed that the overall prevalence of B. bigemina and B. bovis in all bovine samples tested was 64.7% (95% CI = 60.0-69.0) and 35.1% (95% CI = 30.6-39.8), respectively. Only 117/430 (27.2%) animals had a mixed infection. The highest prevalence of 87.5% (95% CI = 77.2-93.5) for B. bigemina was recorded in the Free State province collection sites (Ficksburg, Philippolis and Botshabelo), while North West collection sites had the highest number of animals infected with B. bovis (65.5%; 95% CI = 52.7-76.4). Phylograms were inferred based on B. bigemina-specific gp45 and B. bovis-specific rap-1 nucleotide sequences obtained with Group II nested PCR primers. Phylogenetic analysis of gp45 sequences revealed significant differences in the genotypes of B. bigemina isolates investigated, including those of strains published in GenBank. On the other hand, a phylogeny based on B. bovis rap-1 sequences indicated a similar trend of clustering among the sequences of B. bovis isolates investigated in this study.

Conclusion

This study demonstrates the occurrence of Babesia parasites in cattle from different provinces of South Africa. It was also noted that the situation of Babesia parasitic infection in cattle from certain areas within the surveyed provinces had either reached endemic stability or was progressing towards stability.

Development of a multiplex PCR assay for simultaneous detection of Theileria annulata, Babesia bovis and Anaplasma marginale in cattle

Tropical theileriosis, bovine babesiosis and anaplasmosis are tick-borne protozoan diseases that impose serious constraints on the health and productivity of domestic cattle in tropical and sub-tropical regions of the world. A common feature of these diseases is that, following recovery from primary infection, animals become persistent carriers of the pathogen and continue to play a critical role in disease epidemiology, acting as reservoirs of infection. This study describes development and evaluation of multiplex and single PCR assays for simultaneous detection of Theileria annulata, Babesia bovis and Anaplasma marginale in cattle. Following in silico screening for candidate target genes representing each of the pathogens, an optimised multiplex PCR assay was established using three primer sets, cytob1, MAR1bB2 and bovar2A, for amplification of genomic DNA of T. annulata, A. marginale and B. bovis respectively. The designed primer sets were found to be species-specific, generating amplicons of 312, 265 and 166 base pairs, respectively and were deemed suitable for the development of a multiplex assay. The sensitivity of each primer pair was evaluated using serial dilutions of parasite DNA, while specificity was confirmed by testing for amplification from DNA of different stocks of each pathogen and other Theileria, Babesia and Anaplasma species. Additionally, DNA preparations derived from field samples were used to evaluate the utility of the single and multiplex PCRs for determination of infection status. The multiplex PCR was found to detect each pathogen species with the same level of sensitivity, irrespective of whether its DNA was amplified in isolation or together with DNA representing the other pathogens. Moreover, single and multiplex PCRs were able to detect each species with equal sensitivity in serially diluted DNA representing mixtures of T. annulata, B. bovis and A. marginale, and no evidence of non-specific amplification from non-target species was observed. Validation that the multiplex PCR efficiently detects single and mixed infections from field samples was demonstrated. The developed assay represents a simple and efficient diagnostic for co-detection of tropical theileriosis, bovine babesiosis and anaplasmosis, and may be a valuable tool for epidemiological studies aimed at assessing the burden of multiple infection with tick-borne pathogens and improving control of the associated diseases in endemic regions.

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.

Risk factors associated with the frequency of antibodies against Babesia bovis and Babesia bigemina in cattle in southern Mozambique

The study aimed to evaluate the risk factors associated with the frequency of IgG antibodies against Babesia bovis and B. bigemina in cattle in southern Mozambique. Eight hundred and nine serum samples were collected from cattle in three provinces namely Maputo, Gaza and Inhambane, and tested by indirect enzyme-linked immunosorbent assay (i-ELISA) to assess the humoral immune response towards B. bovis and B. bigemina. The chi-square test at 5% significance was used to determine whether there was an association between gender, age and geographic origin of seropositive animals. The overall prevalence was 78.8% (548/695) for B. bovis and 76.0% (528/695) for B. bigemina. The origin of the animals showed a significant association (p<0.05) with seropositivity to both agents, while gender and age was not associated (p>0.05). Maputo province had the highest rate of positive animals, with 93.7% (118/126) for B. bovis and 97.6% (123/126) for B. bigemina. In Gaza province 77.3% (321/415) of the animals were positive for B. bovis and 67.5% (280/415) for B. bigemina, while in the province of Inhambane the levels of seropositivity were 70.8% (109/154) and 81.2% (125/154) for B. bovis and B. bigemina respectively. In the present study, the frequency of cattle positive for B. bovis and B. bigemina was shown to increase among older age groups, suggesting that infection and re-infection persisted even after the primary infection. Thus, this region is considered to be in a state of enzootic stability with regards to B. bovis and B. bigemina.

Prevalence and genetic diversity of Babesia and Anaplasma species in cattle in Sudan

Disease prevalence studies are one of the most valuable tools to demonstrate the risk or impact of certain infections in local and global economies. The data obtained in these studies contribute to develop strategies for disease control. The present study aims to provide information about the prevalence of babesiosis and anaplasmosis in the northern regions of Sudan. Blood samples from four different states of Sudan were collected from apparently healthy cattle (n=692), DNA was extracted and the prevalence of Babesia and Anaplasma species was analyzed by PCR. The results confirmed the presence of Babesia bigemina, Babesia bovis and Anaplasma marginale in cattle in northern Sudan with overall prevalence rates of 4.0%, 1.9% and 6.1%, respectively. Statistical analysis revealed that the prevalence of B. bigemina, B. bovis and A. marginale varies significantly between Sudanese states as well as in different age groups, while gender seems not to have a significant effect on the prevalence of these pathogens among Sudanese cattle. The highest prevalence for B. bigemina was found in the Aljazirah State while the highest number of A. marginale positive samples was reported in River Nile.

Development and evaluation of two nested PCR assays for the detection of Babesia bovis from cattle blood

We developed and evaluated two nested polymerase chain reaction (nPCR) assays for the diagnosis of Babesia bovis infection in cattle based on two membrane protein genes from B. bovis, BBOV_IV005650 (BV5650) and BBO_IV008970 (BV8970). The specificities and sensitivities of the tests were compared with B. bovis Rhoptery associated protein 1 gene (RAP-1) nPCR. The specificity of the tests was 100% for B. bovis DNA. The sensitivities of nPCR to B. bovis from the in vitro cultured parasites were as low as 10(-8)%, 10(-6)%, and 10(-7)% parasitemia for BV5650, BV8970, and RAP-1 nPCR, respectively. The nPCR detected as little as 1 fg genomic DNA per test for BV5650 and 100fg per test for both BV8970 and RAP-1 genes. For field applications, the sensitivity was evaluated to a total of 165 field samples from Ghana, Mongolia, Brazil and Japan. The nPCR assay of BV5650 was the most sensitive for the detection of B. bovis from the field samples. The BV5650 nPCR assay provides a good diagnostic tool for laboratory diagnostic assessment of B. bovis infection in cattle worldwide.

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.

Development and evaluation of a nested PCR based on spherical body protein 2 gene for the diagnosis of Babesia bovis infection

We developed and evaluated a nested PCR assay for the diagnosis of Babesia bovis infection in cattle based on the spherical body protein 2 gene (SBP2) from B. bovis. The specificity and sensitivity of the test were compared with the B. bovis RAP-1 gene nPCR. The SBP2 primers have specificities of 100% for B. bovis DNA. The sensitivity of the SBP2 nPCR to B. bovis from the in vitro cultured parasites was higher than that of the B. bovis RAP-1 gene nPCR, and a parasitemia as low as 10(-8)% was detected. The sensitivity of the SBP2 nPCR to B. bovis-diluted genomic DNA was also higher than that of B. bovis RAP-1 gene nPCR, and as little as 1fg per test detected. For field applications, the sensitivity to a total of 145 field samples from Ghana, Mongolia, and Brazil was evaluated. The nPCR assay of spherical body protein-2 gene detected 87.6% (127/145), while B. bovis RAP-1 gene nPCR detected 37.2% (51/145) of the total samples examined. This nPCR assay provides a good diagnostic tool for the laboratory diagnostic assessment of B. bovis infection in cattle worldwide.