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Preventive Veterinary Medicine May 2024Tick-borne pathogens of the genus Anaplasma cause anaplasmosis in livestock and humans, impacting health and livelihoods, particularly in Africa. A comprehensive review... (Review)
Review
Tick-borne pathogens of the genus Anaplasma cause anaplasmosis in livestock and humans, impacting health and livelihoods, particularly in Africa. A comprehensive review on the epidemiology of Anaplasma species is important to guide further research and for implementation of control approaches. We reviewed observational studies concerning Anaplasma species amongst cattle in Africa. Peer-reviewed studies published in PubMed, Google Scholar, and Web of Science - from database inception to 2022 - were searched. The quality of individual studies was assessed using the Joanna Briggs Institute Critical Appraisal Tool and the pooled prevalences by diagnostic method were estimated using random-effects models. Heterogeneity across the studies was tested and quantified using the Cochran's Q statistic and the I statistic. Potential sources of heterogeneity were investigated by subgroup analysis. A total of 1117 records were retrieved and at the end of the screening, 149 records (155 studies) were eligible for this meta-analysis. The occurrence of Anaplasma species was reported in 31/54 countries in all regions. Seven recognised species (A. marginale, A. centrale, A. phagocytophilum, A. platys, A. capra, A. bovis, A. ovis) and nine uncharacterised genotypes (Anaplasma sp. Hadesa; Anaplasma sp. Saso; Anaplasma sp. Dedessa; Anaplasma sp. Mymensingh; Anaplasma sp. Lambwe-1; Candidatus Anaplasma africae; Anaplasma sp.; Candidatus Anaplasma boleense) were reported in African cattle. Anaplasma marginale was the most frequently reported (n=144/155 studies) and the most prevalent species (serology methods 56.1%, 45.9-66.1; direct detection methods 19.9%, 15.4-24.7), followed by A. centrale (n=26 studies) with a prevalence of 8.0% (95% CI: 4.8-11.9) and A. platys (n=19 studies) with prevalence of 9.7% (95% CI: 5.4-15.2). Anaplasma marginale, A. centrale and A. platys were reported in all Africa's regions, while A. ovis and A. capra were reported only in the northern and central regions. The uncharacterised Anaplasma taxa were mostly detected in the eastern and southern regions. Subgroup analysis showed that significant determinants for A. marginale exposure (serology) were geographical region (p=0.0219), and longitude (p=0.0336), while the technique employed influenced (p<0.0001) prevalence in direct detection approaches. Temperature was the only significant variable (p=0.0269) for A. centrale. These findings show that various Anaplasma species, including those that are zoonotic, circulate in African cattle. There is need for more genetic and genome data, especially for unrecognised species, to facilitate effective identification, improve livestock and minimise the health risk in human populations. Additional epidemiological data including pathogen occurrence, tick vectors and host range, as well as pathogenicity are essential.
PubMed: 38733736
DOI: 10.1016/j.prevetmed.2024.106214 -
BMC Veterinary Research May 2024Members of the Anaplasmataceae family, such as the Anaplasma and Ehrlichia species, cause economic losses and public health risks. However, the exact economic impact has...
BACKGROUND
Members of the Anaplasmataceae family, such as the Anaplasma and Ehrlichia species, cause economic losses and public health risks. However, the exact economic impact has not been comprehensively assessed in Mozambique due to limited data available on its basic epidemiology. Therefore, we investigated the molecular occurrence and identity of Anaplasma and Ehrlichia spp. infecting beef cattle in Maputo province, Mozambique.
METHODS
A total of 200 whole blood samples were collected from apparently healthy beef cattle. Whole blood DNA was extracted and tested for presence of Anaplasma spp. and Ehrlichia ruminantium DNA through amplification of the 16S rRNA and map1 genes. Positive samples to Anaplasma spp. were subject to PCR assay targeting the A. marginale-msp5 gene. Amplicons obtained were purified, sequenced and subject to phylogenetic analyses.
RESULTS
Anaplasma spp., A. marginale and E. ruminantium were detected in 153 (76.5%), 142 (71%) and 19 (9.5%) of all the samples analyzed, respectively. On this same sample group, 19 (9.5%) were co-infected with A. marginale and E. ruminantium. The 16S rRNA sequences of Anaplasma spp. obtained were phylogenetically related to A. marginale, A. centrale and A. platys. Phylogenetic analysis revealed that A. marginale-msp5 nucleotide sequences were grouped with sequences from Asia, Africa and Latin America, whereas E. ruminantium-map1 DNA nucleotide sequences were positioned in multiple clusters.
CONCLUSION
Cattle in Maputo Province are reservoirs for multiple Anaplasma species. A high positivity rate of infection by A. marginale was observed, as well as high genetic diversity of E. ruminantium. Furthermore, five new genotypes of E. ruminantium-map1 were identified.
Topics: Animals; Mozambique; Cattle; Anaplasmosis; Cattle Diseases; RNA, Ribosomal, 16S; Phylogeny; Ehrlichiosis; Anaplasma marginale; Ehrlichia ruminantium; DNA, Bacterial; Bacterial Outer Membrane Proteins; Polymerase Chain Reaction
PubMed: 38730389
DOI: 10.1186/s12917-024-04045-4 -
Infection and Immunity May 2024is an obligate, intracellular, tick-borne bacterial pathogen that causes bovine anaplasmosis, an often severe, production-limiting disease of cattle found worldwide....
is an obligate, intracellular, tick-borne bacterial pathogen that causes bovine anaplasmosis, an often severe, production-limiting disease of cattle found worldwide. Methods to control this disease are lacking, in large part due to major knowledge gaps in our understanding of the molecular underpinnings of basic host-pathogen interactions. For example, the surface proteins that serve as adhesins and, thus, likely play a role in pathogen entry into tick cells are largely unknown. To address this knowledge gap, we developed a phage display library and screened 66 . proteins for their ability to adhere to tick cells. From this screen, 17 candidate adhesins were identified, including OmpA and multiple members of the Msp1 family, including Msp1b, Mlp3, and Mlp4. We then measured the transcript of and all members of the gene family through time, and determined that , , and have increased transcript during tick cell infection, suggesting a possible role in host cell binding or entry. Finally, Msp1a, Msp1b, Mlp3, and OmpA were expressed as recombinant protein. When added to cultured tick cells prior to infection, all proteins except the C-terminus of Msp1a reduced entry by 2.2- to 4.7-fold. Except OmpA, these adhesins lack orthologs in related pathogens of humans and animals, including and the spp., thus limiting their utility in a universal tick transmission-blocking vaccine. However, this work greatly advances efforts toward developing methods to control bovine anaplasmosis and, thus, may help improve global food security.
PubMed: 38727242
DOI: 10.1128/iai.00540-23 -
Ticks and Tick-borne Diseases Jul 2024Bovine anaplasmosis is a tick-borne disease caused by Anaplasma marginale in the United States. The objective of this study was to use a survey tool to generate...
Bovine anaplasmosis is a tick-borne disease caused by Anaplasma marginale in the United States. The objective of this study was to use a survey tool to generate information for beef operations in California on anaplasmosis prevention and control management, including to what extent management activities were informed by perceived herd-level exposure to A. marginale infection or occurrence of clinical anaplasmosis cases. We mailed 2,621 questionnaires with questions on Anaplasma status, herd demographics, anaplasmosis control and prevention measures, and environmental factors to beef ranchers in California in October 2020. Survey-weighted chi-square tests were used to compare management differences according to perceived Anaplasma infection status. Generalized estimating equations (GEEs) were used to analyze whether region of California, management practices, or environmental factors were associated with reported clinical cases of anaplasmosis in the previous five years. A total of 466 questionnaires describing 749 herds were obtained and used in this study. Use of management measures, including deliberate exposure of calves to ticks, vaccination for Anaplasma, infection control through antibiotics in feed, maintaining a completely closed herd, blood testing for Anaplasma on all herd additions, and taking no anaplasmosis control and prevention measures, were significantly different between herds with or without perceived A. marginale infection based on producers' self-declared status. The overall perceived prevalence for Anaplasma infection and reported clinical cases of anaplasmosis at the herd level was 26.0 % (95 % CI: 24.3-27.7 %) and 17.1 % (95 % CI: 15.6-18.6 %) respectively, with the highest perceived infection and case numbers reported in the Central Coast region. In the GEE model, higher odds of reporting clinical cases of anaplasmosis in the previous five years were observed in cattle located in the Central Coast region, cattle within a large herd, cattle that are treated with tick/fly control, cattle in a completely closed herd, and cattle receiving Anaplasma vaccine. Anaplasma infection and bovine anaplasmosis status may be underestimated in beef herds in California based on previous study results. Changing needles between cattle after injections and conducting blood testing for Anaplasma on herd additions are important Anaplasma management measures that are infrequently implemented in beef herds in California. The results show a need for producer education to improve producers' awareness of bovine anaplasmosis and implement proper measures for disease control and prevention.
Topics: Animals; Cattle; Anaplasma marginale; Anaplasmosis; California; Cattle Diseases; Male; Female; Surveys and Questionnaires
PubMed: 38643720
DOI: 10.1016/j.ttbdis.2024.102346 -
Veterinary World Feb 2024Bovine anaplasmosis (BA) is one of the most important diseases of ruminants worldwide, causing significant economic losses in the livestock industry due to the high...
BACKGROUND AND AIM
Bovine anaplasmosis (BA) is one of the most important diseases of ruminants worldwide, causing significant economic losses in the livestock industry due to the high morbidity and mortality in susceptible cattle herds. is the main causative agent of BA occurring worldwide in tropical and subtropical regions. This study aimed to investigate the first molecular detection and genetic diversity of in dairy cattle in Khon Kaen Province, Thailand.
MATERIALS AND METHODS
Blood samples were collected from 385 lactating cows from 40 dairy farms in five districts of Khon Kaen, regardless of age and health status. To detect , all DNA preparations were used for molecular diagnosis using a single polymerase chain reaction with the gene target. A phylogenetic tree was constructed from the gene sequences using molecular genetic characterization. Genetic diversity was calculated as haplotype diversity, haplotype number, number of nucleotide differences, nucleotide diversity, and average number of nucleotide differences.
RESULTS
The overall prevalence of was 12.72% (49/385). The highest prevalence (17.19%) was found in Ubolratana district, followed by Muang, Kranuan, Khao Suan Kwang, and Nam Phong districts (14.94%, 14.74%, 13.79%, and 3.70%, respectively). Phylogenetic analysis showed that was closely related to isolates from Australia (98.96%), China (99.68%), Spain (99.74%), and the USA (99.63%).
CONCLUSION
The molecular prevalence of BA in dairy cattle is the first to be observed in this area, and the genetic variability with separated clusters shown in the gene of revealed species variation in dairy cattle. This significant genetic diversity contributes to the understanding of the diversity of and will be important for the control and prevention of in dairy cattle.
PubMed: 38595664
DOI: 10.14202/vetworld.2024.389-397 -
Ecology and Evolution Apr 2024Interactions within the tick microbiome involving symbionts, commensals, and tick-borne pathogens (TBPs) play a pivotal role in disease ecology. This study explored...
Interactions within the tick microbiome involving symbionts, commensals, and tick-borne pathogens (TBPs) play a pivotal role in disease ecology. This study explored temporal changes in the microbiome of , an important cattle tick vector, focusing on its interaction with . To overcome limitations inherent in sampling methods relying on questing ticks, which may not consistently reflect pathogen presence due to variations in exposure to infected hosts in nature, our study focused on ticks fed on chronically infected cattle. This approach ensures continuous pathogen exposure, providing a more comprehensive understanding of the nesting patterns of in the microbiome. Using next-generation sequencing, microbiome dynamics were characterized over 2 years, revealing significant shifts in diversity, composition, and abundance. exhibited varying associations, with its increased abundance correlating with reduced microbial diversity. Co-occurrence networks demonstrated 's evolving role, transitioning from diverse connections to keystone taxa status. An integrative approach involving node removal unveils the impact of on network stability, highlighting its role in conferring robustness to the microbial community. This study provides insights into the intricate interplay between the tick microbiome and , shedding light on potential avenues for controlling bovine anaplasmosis through microbiome manipulation.
PubMed: 38571811
DOI: 10.1002/ece3.11228 -
Scientific Reports Apr 2024Anaplasma marginale infection is one of the most common tick-borne diseases, causing a substantial loss in the beef and dairy production industries. Once infected, the...
Anaplasma marginale infection is one of the most common tick-borne diseases, causing a substantial loss in the beef and dairy production industries. Once infected, the pathogen remains in the cattle for life, allowing the parasites to spread to healthy animals. Since clinical manifestations of anaplasmosis occur late in the disease, a sensitive, accurate, and affordable pathogen identification is crucial in preventing and controlling the infection. To this end, we developed an RPA-CRISPR/Cas12a assay specific to A. marginale infection in bovines targeting the msp4 gene. Our assay is performed at one moderately high temperature, producing fluorescent signals or positive readout of a lateral flow dipstick, which is as sensitive as conventional PCR-based DNA amplification. This RPA-CRISPR/Cas12a assay can detect as few as 4 copies/μl of Anaplasma using msp4 marker without cross-reactivity to other common bovine pathogens. Lyophilized components of the assay can be stored at room temperature for an extended period, indicating its potential for field diagnosis and low-resource settings of anaplasmosis in bovines.
Topics: Cattle; Animals; Anaplasma marginale; Anaplasmosis; CRISPR-Cas Systems; Cattle Diseases; Tick-Borne Diseases
PubMed: 38570576
DOI: 10.1038/s41598-024-58169-6 -
Microorganisms Mar 2024is a persistent ectoparasite of cattle that causes bovine anaplasmosis and babesiosis, causing economic losses worldwide. Chemical treatment is the primary method for...
is a persistent ectoparasite of cattle that causes bovine anaplasmosis and babesiosis, causing economic losses worldwide. Chemical treatment is the primary method for tick control, but the emergence of pesticide-resistant ticks is a major challenge. Alternative biocontrol strategies utilizing entomopathogenic microorganisms are being explored. This study aimed to validate the species identification and assess the efficacy of four strains of bacteria ( S1 and S-2, , and ) previously reported as being entomopathogenic to ticks. According to the bioassays, S-1 exhibited the greatest degree of reproductive inhibition (47%), followed by (44.3%) at a concentration of 1 × 10 cfu/mL. displayed decreased reproductive inhibition (6.3%). In an additional bioassay, S-1 exhibited a significant larval mortality of 67.63%, followed by with 66.75%, S-2 with 64.61%, and with 28.18% mortality. The common signs of infection observed on these ticks included swelling, yellowish exudate on the hypostome, and reduced limb mobility and color change, except for , which did not cause color changes. These bacteria were naturally found on bovine skin. However, further studies are needed to confirm their potential as promising alternatives or complementary agents to existing acaricidal compounds.
PubMed: 38543602
DOI: 10.3390/microorganisms12030551 -
Parasites & Vectors Mar 2024In 2022, fluralaner was launched on the market for use in the control of the cattle tick Rhipicephalus microplus after showing 100% efficacy in registration trials...
BACKGROUND
In 2022, fluralaner was launched on the market for use in the control of the cattle tick Rhipicephalus microplus after showing 100% efficacy in registration trials against the causative agents of cattle tick fever (TFAs). The aim of the present study was to determine whether a strategic control regimen against R. microplus using fluralaner (FLU) in Holstein calves grazing in a tropical region would alter the enzootic stability status of cattle tick fever, triggering outbreaks in these animals up to 22 months age.
METHODS
In this study, a group of calves treated with FLU was compared with a control group treated with the regimen currently being used on the farm, which consisted of the fipronil + fluazuron formulation (FIFLUA). In the first experiment, the efficacy of the FIFLUA pour-on formulation was evaluated in a field study. In the second experiment, which lasted 550 days, two experimental groups (n = 30/group) of Holstein calves naturally infested with R. microplus were analyzed. Calves aged 4 to 10 months received either a specific treatment regimen with FLU (experimental group) or FIFLUA (control group). During this period, tick counts, animal weight measurement, feces collection (to determine eggs and oocysts per gram of feces), tick fever monitoring, blood smears (to ascertain enzootic stability of the herd), PCR testing for TFAs and serology (indirect enzyme-linked immunosorbent assay [iELISA]) were performed. All calves were evaluated for signs of tick fever between ages 11 and 22 months.
RESULTS
FIFLUA showed an acaricidal efficacy of > 90% from post-treatment days 14 to 35. Regarding treatments against the TFAs, the average number of treatments was similar between groups, but animals treated with FLU had a smaller reduction in packed cell volume on some of the evaluation dates of the second and third treatment against TFAs. In calves aged 10 months in the FLU group, B. bovis was not detected by PCR (0/15 samples), 40% of the samples had antibody titers and 33% (10/30) of the samples had positive blood smears. Regarding B. bigemina, > 86% of the samples in both groups tested positive for B. bigemina DNA and antibodies; there was no difference in the antibody titers between the groups. There were no clinical cases of cattle tick fever in calves aged 11 to 22 months.
CONCLUSIONS
In comparison with the control treatment, the strategic control regimen against R. microplus with FLU that was implemented in the present study did not negatively affect the enzootic stability status of A. marginale and B. bigemina in the herd up to 22 months of age. The enzootic stability status of B. bovis was not reached by either group. These results likely represent a characteristic of the local tick population, so further studies should be performed.
Topics: Animals; Cattle; Tick Control; Tick Infestations; Cattle Diseases; Ovum; Babesiosis; Anaplasmosis; Rhipicephalus; Isoxazoles
PubMed: 38461304
DOI: 10.1186/s13071-024-06212-w -
The Veterinary Quarterly Dec 2024Understanding the spatial and temporal distribution of is crucial for identifying areas of high prevalence for targeted disease control. This research was aimed at...
Understanding the spatial and temporal distribution of is crucial for identifying areas of high prevalence for targeted disease control. This research was aimed at modelling and mapping the potential distribution, and identify hotspots as well as significant variables explaining the occurrence of the disease. The Getis Ord G* statistic for Hotspot analysis was used as well as MaxEnt ecological niche modelling. The effects of time, land-use, and agro-ecological regions on occurrence were tested using Analysis of Variance (ANOVA). Results showed that several districts in Zimbabwe are suitable for the occurence of the disease for example Binga, Seke, Buhera, Kwekwe, Gweru, Mhondoro, Chegutu, Sanyati, and in the North: Mbire, Muzarabani, Mt Darwin, Shamva, Bindura, Zvimba and Makonde. Morbidity and mortality hotspots were detected in Gokwe-south, Kwekwe, and Chirumhanzu districts. Binga, Gokwe-south, Gutu, Hurungwe, Mazoe, Nkayi, Shamva, and Kwekwe districts also experienced high disease incidences. Temperature seasonality, precipitation seasonality, mean diurnal range, and isothermality were the most important variables in explaining 93% of distribution. Unlike land-use and agro-ecological regions, time (months) had a significant effect on occurrence with July and September having significantly ( < 0.05) higher cases and deaths than the rest of the months. The results of this study provide insights into the management strategies and control of in Zimbabwe. It is thus concluded that geo-spatial techniques, combined with ecological niche modelling can provide useful insights into disease prevalence and distribution and hence can contribute to effective management and control of in Zimbabwe.
Topics: Animals; Cattle; Anaplasmosis; Zimbabwe; Cattle Diseases
PubMed: 38279663
DOI: 10.1080/01652176.2024.2306210