Epidemiology and risk factors associated with Anaplasma marginale infection of cattle in Peninsular Malaysia

Molecular epidemiology and associated risk factors of Anaplasma marginale in camels and possible co-infections

Anaplasma spp. is an important pathogen that affects a wide range of animals, including camels. The current study aimed to assess the prevalence of six Anaplasma spp. in 400 camels from Ismailia, Suez, and Sharkia governorates in northern Egypt, as well as their associated risk factors and possible coinfections. Blood and fecal samples were examined using bacterial culture, the vitek2 system, and PCR. Genetic divergence among Anaplasma marginale (A. marginale) isolates was characterized using the msp4 gene. The overall prevalence of A. marginale was 19.5%. Sequencing analysis confirmed the PCR results, and a single A. marginale genotype was recognized by msp4 sequencing. The phylogenetic tree indicated that the study A. marginale isolates clustered together and were close to Egyptian A. marginale identified from buffalo (OP142725 and OP142726). Age, sex, housing type, tick infestation, body conditions, and tick control factors were significantly associated with camel anaplasmosis using a logistic regression model (odds ratio >1, P < 0.05). Multivariate logistic regression analysis revealed that the infection was 2.03, 1.9, 2.6, 1.9, and 1.8 times higher in females, semi-enclosed housing, ages >5 years, tick infestation, and emaciated camels. The risk of infection due to a tick control factor increased by 4.4 and 2.6 times when no control was applied or with irregular control, respectively. This is the first molecular report of A. marginale infection in camels in Ismailia, Suez, and Sharkia in northern Egypt, indicating a moderate prevalence of A. marginale and the involvement of multiple bacterial infections, mainly Escherichia coli and Salmonella spp. Thus, it is necessary to develop effective management and control for camel anaplasmosis.

Can herd seroprevalence be used as an indicator of enzootic stability for bovine anaplasmosis? Insights from a case-control field study in Brazil

Bovine anaplasmosis presents a significant challenge to livestock production in tropical, subtropical, and temperate regions. For many years, the concept of enzootic stability/instability (initially established for babesiosis) and herd seroprevalence as an indicator of outbreak risks have been applied to anaplasmosis. However, this model has never been definitively validated for Anaplasma marginale. The objective of this study was to examine the relationship between herd immunity (seroprevalence) and the occurrence of anaplasmosis outbreaks in Southern Brazil. A case-control study was conducted, categorizing farms into two groups: cases (farms with a history of clinical anaplasmosis) and controls (those without anaplasmosis). Thirteen farms were identified as "cases", while 23 were identified as "controls". A substantial difference in seroprevalence distribution between the two groups was observed. The majority of "control" farms exhibited over 75% of animals with antibodies to A. marginale in both calves and heifers, whereas the majority of "case" farms had a seropositive cattle percentage below 75%. Additionally, twelve months after cattle serology tests, we conducted a prospective follow-up survey to identify any clinical cases of anaplasmosis. Statistical associations (P < 0.05) were found between both retrospective and prospective anaplasmosis outbreaks and the hypothetical threshold of herd seroprevalence (75%). We hypothesize that herd seroprevalence may be an indicator of the risk of occurrence of clinical anaplasmosis. It appears that the epidemiology of cattle anaplasmosis, at least in our conditions, aligns with the well-known model of enzootic stability/instability originally applied to bovine babesiosis.

Molecular prevalence of Anaplasma spp. in cattle and assessment of associated risk factors in Northeast Thailand

Background and Aim

Anaplasma spp. are common rickettsia species described in ruminant hosts, including cattle. The clinical signs of anaplasmosis range from asymptomatic to mortality. However, there are insufficient studies on epidemiology surveys of this blood pathogen. This study aimed to estimate the prevalence and risk factors of anaplasmosis in beef and dairy cattle in Northeast, Thailand.

Materials and Methods

A total of 187 blood samples of beef and dairy cattle were collected from five provinces in Northeast Thailand. Anaplasma spp. infections were screened by microscopic examination and polymerase chain reaction targeting specific genes (msp4 gene for Anaplasma marginale and 16S rRNA gene for Anaplasma platys and Anaplasma bovis). Moreover, the associated risk factors for the infections were evaluated.

Results

Overall, blood samples from cattle revealed that 17.6% (33/187) were positive for Anaplasma spp. by microscopic examination and 20.8% (39/187) were positive by DNA amplification. Of these 20.8%, 17.6% were A. marginale and 3.2% were A. platys. However, A. bovis infection was not detected. Infection with Anaplasma spp. and A. marginale showed a significant association with breed and gender (p < 0.05) while age and packed cell volume levels showed no significant statistical relationship between Anaplasma spp. infected and uninfected animals.

Conclusion

This study indicated that anaplasmosis is distributed in beef and dairy cattle in Thailand; therefore, prevention and control strategies for these pathogens should be improved. This information will benefit veterinarians and cowherds by avoiding vector exposure and eliminating tick breeding sites.

High genetic diversity of Anaplasma marginale infecting dairy cattle in northeastern Brazil

Anaplasma marginale is an obligate intracellular Gram-negative bacterium found in ruminants' erythrocytes and is the etiological agent of bovine anaplasmosis. The bacterium's genetic diversity has been characterized based on sequences of major surface proteins (MSPs), such as MSP1α. The aim of the present study was to investigate the genetic diversity of A. marginale in cattle in the state of Maranhão, northeastern Brazil. To this end, 343 blood samples were harvested and subjected to iELISA assays using the recombinant surface protein MSP5. Out of 343 blood samples, 235 (68.5%) were randomly chosen and submitted to DNA extraction, qPCR and conventional PCR targeting the msp1α gene to determine amino acid sequences and classify the genotypes. The iELISA results showed 81.34% seropositivity (279/343), whereas qPCR revealed 224 positive samples (95.32%). Among these qPCR-positive samples, 67.4% (151/224) were also positive in the cPCR. Among the 50 obtained sequences, 21 strains had not been previously reported. Regarding the genotypes, H (26/50) and E (18/50) were identified most often, while genotypes F and C were only identified twice each and B and G once each. In conclusion, high prevalence and genetic diversity for A. marginale were observed in dairy cattle herds in the state of Maranhão.

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.

Mo­lecular evidence and epidemiology of “Candidatus Mycoplasma haemobos” among cattle in Peninsular Malaysia using the 16S rRNA gene

Haemotropic Mycoplasma infection among cattle has not been seriously looked into, despite the fact it is associated with poor weight gain and depression. One thousand and forty-five blood samples from apparently healthy cattle from forty-three farms within the entire Peninsular Malaysia were exa­mined over a one-year period. Using polymerase chain reaction to amplify the 16S rRNA gene, the presence of “Candidatus Mycoplasma haemobos” as one of the haemotropic Mycoplasma species that affects cattle in the country was detected. Forty-seven percent of the sampled population was positive for “C. M. haemobos”, with the antigen present in all herds sampled. Breed of cattle, gender, age, production type, physiological status, herd size, management system, farm size, farm age, prophylactic treatment against blood parasites, presence of ticks, frequency of de-ticking, zone, closeness to forest, closeness to waste area, closeness to human settlement and closeness to body of water were all significantly associated (P<0.05) with the detection of “C. M. haemobos”. The findings from this study will be pivotal in government policy on this blood Mycoplasma infection, as the study happens to be the first comprehensive molecular survey of the microorganism in the country.

Anaplasmosis in Animals

Anaplasmosis is a vector-borne, infectious and non-contagious disease. The disease is caused by various pathogens of the genus Anaplasma. The different species cause different types of anaplasmosis depending on which cells that are infected in the mammalian host. Anaplasmosis has a wide host range, including humans, and it is distributed worldwide. The zoonotic potential of some species is of great importance in regards to public health concerns. This review presents information about anaplasmosis in animals and its prevalence in Europe, and other countries in the world.

Anaplasma and Theileria Pathogens in Cattle of Lambwe Valley, Kenya: A Case for Pro-Active Surveillance in the Wildlife-Livestock Interface

Tick-borne pathogens (TBPs) are major constraints to livestock production and a threat to public health in Africa. This cross-sectional study investigated the risk of infection with TBPs in cattle of Lambwe Valley, Kenya. Blood samples of 680 zebu cattle from 95 herds in six geospatial clusters within 5 km of Ruma National Park were screened for bacterial and protozoan TBPs by high-resolution melting analysis and sequencing of PCR products. We detected Anaplasma bovis (17.4%), Anaplasma platys (16.9%), Anaplasma marginale (0.6%), Theileria velifera (40%), and Theileria mutans (25.7%), as well as an Anaplasma sp. (11.6%) that matched recently reported Anaplasma sp. sequences from Ethiopia. Babesia, Rickettsia, and Ehrlichia spp. were not detected. The animal and herd-level prevalences for TBPs were 78.5% (95% confidence intervals (CI): 75.3, 81.5) and 95.8% (95% CI: 91.8, 99.8), respectively. About 31.6% of cattle were co-infected with 13 combinations of TBPs. The prevalence of TBPs differed between clusters and age, but the risk of infection was not associated with sex, herd size, or the distance of homesteads from Ruma. This study adds insight into the epidemiology of TBPs around Ruma and highlights the need for proactive surveillance of TBPs in livestock–wildlife interfaces.

Clinical signs, prevalence, and hematobiochemical profiles associated with Anaplasma infections in sheep of North Iraq

Background and Aim:

Anaplasma infection is a worldwide prevalent condition that causes significant economic losses in affected flocks. This study was conducted to determine the prevalence and clinical signs associated with ovine anaplasmosis as well as the hematological and biochemical changes associated with the disease in natural infection in North Iraq.

Materials and Methods:

A total of 420 sheep were appropriately examined, and the clinical signs were documented accordingly. Blood samples were collected and subjected to parasitological, hematological, and biochemical analyses.

Results:

Anaplasma-infected sheep displayed the following clinical signs: Paleness of the mucous membrane, bloody diarrhea, emaciation, pyrexia, jaundice, nasal discharge, coughing, loss of wool, nervous signs, hemoglobinuria, and lacrimation. The prevalence of Anaplasma infection was 66.19%, and female sheep were significantly (p<0.05) more infected than male sheep. The hematological and biochemical parameters were significantly different between Anaplasma-positive and Anaplasma-negative sheep.

Conclusion:

Anaplasma infection among sheep is a significant concern in North Iraq considering its prevalence, clinical signs, and hematological and biochemical findings, which entirely causes significant debilitating effects on sheep productivity. It is important to pay more attention toward managing tick infestation among sheep to reduce the occurrence of this rickettsial disease for a more robust livestock sector of the Iraqi economy.

Molecular detection, prevalence and risk factors of Theileria orientalis infection among cattle in Peninsular Malaysia

There is need to confirm the presence of Theileria orientalis among the cattle population in Peninsular Malaysia and to evaluate the risk factors associated with the infection. To this effect, blood samples were collected from 1045 cattle from 43 farms throughout the entire States of Peninsular Malaysia. The collected blood samples were subjected to DNA extraction and subsequent PCR amplification of the major piroplasm surface protein (MPSP) gene of the haemoprotozoan. Representative positive amplicons were purified, sequenced and compared with other sequences of the MPSP gene of T. orientalis curated from the GenBank. A well-structured questionnaire was used to get information about each cattle, it's demography, the bio-security, environmental and management factors. Univariate and multivariate analysis were used for the statistical evaluation, with significance set at p < 0.05. A total prevalence of 49.76% (520/1045; 95% CI: 46.73 - 52.79) was obtained. Types of breeds, age, production type, herd size, level of farm biosecurity, farm size, presence of other animal species in the farm, management systems and prophylaxis were significantly (p < 0.05) associated with the prevalence of T. orientalis. This study confirmed the presence of T. orientalis and establish that the haemoprotozoan is endemic among cattle in Peninsular Malaysia.

Molecular detection and genetic diversity of Anaplasma marginale based on the major surface protein genes in Thailand

Anaplasma marginale is the rickettsial agent of anaplasmosis, a tick-borne disease, which affects cattle and other ruminants in tropical and subtropical areas of the world, and causing huge economic losses because of decreasing meat and milk production. In the present study, molecular methods have been used to determine the occurrence and genetic diversity of A. marginale, based on the genes encoding the major surface proteins (msps) genes, in blood samples from 520 cattle and 121 buffaloes in the north and northeastern regions of Thailand. The polymerase chain reaction (PCR) results based on the msp4 gene indicated that 66 (10.30%) cattle were positive for A. marginale, whereas no positive result was obtained from buffaloes. The phylogenetic analysis based on the maximum likelihood method using 13, 29 and 27 nucleotide sequences from msp2, msp4, msp5 clones, respectively, revealed that the sequences detected in this study are obviously distributed in different clusters. The sequence analysis demonstrated that msp2 gene is genetically diverse, while msp4 and msp5 genes are conserved in Thailand. These findings corroborated the diversity analysis of the same sequences, which showed 13, 27 and 27 haplotypes of the msp2, msp4 and msp5 genes, respectively. In addition, the entropy analyses of amino acid sequences exhibited 127, 75 and 51 high entropy peaks with values ranging from 0.27119 to 2.45831, from 0.14999 to 2.17552 and from 0.15841 to 1.05453 for MSP2, MSP4 and MSP5, respectively. Therefore, the results indicate a low molecular occurrence of A. marginale in cattle blood samples in Thailand. From these results; however, a high degree of genetic diversity was observed in the analyzed A. marginale population. Hence, our finding could be used to improve the immunodiagnostics and vaccination programs for anaplasmosis.

Molecular detection of porcine Enterocytozoon bieneusi infection in Peninsular Malaysia and epidemiological risk factors associated with potentially zoonotic genotypes

Enterocytozoon bieneusi is an emerging opportunistic pathogen infecting humans, and both domestic and wild pigs are known to harbour zoonotic genotypes. There remains a paucity of information on the prevalence and epidemiology of this enteropathogen in Southeast Asia. The present study was undertaken to determine the molecular prevalence and risk factors associated with E. bieneusi infection among commercially farmed pigs in Malaysia. Faecal samples were collected from 450 pigs from 15 different farms and subjected to nested PCR amplification of the ribosomal internal transcribed spacer (ITS) gene of E. bieneusi. Phylogenetic analysis involved 28 nucleotide sequences of the ITS region of E. bieneusi. An interviewer-administered questionnaire provided information on the animal hosts, farm management systems and environmental factors and was statistically analysed to determine the risk factors for infection. The prevalence of E. bieneusi infection was relatively high (40.7%). The highest prevalence (51.3%) was recorded among the piglets, while the adults showed the lowest level of infection (31.3%). Multivariate analysis indicated that age of the pigs, distance of the farm from human settlement and farm management system were significant risk factors of infection. Three genotypes (EbpA, EbpC and Henan-III) detected among the pigs are potentially zoonotic. The high prevalence of E. bieneusi among locally reared pigs, the presence of zoonotic genotypes and the spatial distribution of pig farms and human settlements warrant further investigation on the possibility of zoonotic transmission.

Molecular Prevalence and Epidemiology of Trypanosoma evansi Among Cattle in Peninsular Malaysia

BACKGROUND

Animal trypanosomiasis (Surra) caused by Trypanosoma evansi (T. evansi) is known to be one of the important haemoprotozoan parasites that causes great economical loss on animal production due to mortality and loss of condition.

METHODS

A cross-sectional study was designed to evaluate the prevalence and risk factors associated with T. evansi infection among cattle in Peninsular Malaysia. Polymerase chain reaction (PCR) was employed on 1045 blood samples collected from 43 farms. A well-structured questionnaire was used to collect data on risk factors associated with T. evansi prevalence. The RoTat 1.2 set of primers was used to amplify products of 205 base pair.

RESULTS

The overall prevalence was found to be 17.9% (187/1045; 95% CI = 15.66-20.31). Trypanosoma evansi was detected among cattle in all the States of Peninsular Malaysia. Breeds of cattle and closeness to waste area, where the risk factors significantly (p < 0.05) associated with the PCR positivity of T. evansi among cattle in Peninsular Malaysia.

CONCLUSION

This appears to be the first time a comprehensive survey on the prevalence and risk factors of T. evansi infection in cattle using molecular tools is been carried out in the entire states of Peninsular Malaysia. The findings from this study will provide baseline information on the molecular prevalence of the haemoflagellate and its associated risk factors among cattle for an improved beef and dairy production in Peninsular Malaysia.

Molecular epidemiology and associated risk factors of Anaplasma marginale and Theileria annulata in cattle from North-western Pakistan

Ticks and tick-borne pathogens are one of the major threats to livestock production worldwide. The aim of present study is to specify the molecular epidemiology and its associated risk factors of two well-distributed tick-borne pathogens Anaplasma marginale and Theileria annulata in cattle population from North-western Pakistan. Blood samples were Collected from 60 (32.6 %) local breed cattle, 101 (54.9 %) from crossbreed, and 24 (13.0 %) from exotic breed with total of 184 blood samples. Species-specific PCR assays were performed to detect the presence of A. marginale and T. annulata based on 16S rRNA and 18S rRNA genetic makers respectively. PCR results showed that A. marginale was 16.3 % prevalent and T. annulata was 29.9 % prevalent in the study area with a total prevalence rate of 46.2 % (85/184) of the tested blood samples. District wise analysis revealed that both pathogens were highly prevalent in district Dir Upper (13.6 %) and least prevalent in district Chitral (10.3 %). Univariable analysis of risk factors showed that only breed and acaricidal treatment were significant determinants (P < 0.05) for A. marginale infection, however, in case of T. annulata infection; breed, age, gender, grazing practice, and acaricidal treatment were potential determinants (P < 0.05). Multivariable analysis specified that breed and acaricidal treatment were considered as significant risk factors for A. marginale infection (P < 0.05) whereas acaricidal treatment was found to be a significant determinant for T. annulata infection (P < 0.05). Phylogenetic analysis indicated that A. marginale 16S rRNA and T. annulata 18S rRNA isolates showed similarities and shared phylogeny with same isolates reported from Asia. This is the first molecular report on the epidemiology and risk factors analysis of A. marginale and T. annulata infections in cattle population from NW Pakistan. Further large scale study is required to investigate molecular, epidemiological and genotypic aspects as well as potential risk factors analysis from the country to facilitate designing strategies to control tick-borne pathogen and reduce losses to cattle industry.

Epidemiology and genetic diversity of Anaplasma marginale in Zamora-Chinchipe, Ecuador

Bovine anaplasmosis, caused by the tick-borne pathogen Anaplasma marginale, is a hemolytic disease that constitutes a major constraint to cattle production in tropical and subtropical regions including Ecuador. However, the epidemiological situation of this hemoparasitosis in Ecuador is poorly characterized. The present study was aimed to determine the prevalence and genetic diversity of A. marginale in cattle of Ecuador. A cross-sectional study was carried out covering several farms from six out nine cantons of the Zamora-Chinchipe province. A total of 185 cattle were randomly selected and blood samples were collected from the animals. The studied group of animals included six breeds, three age groups, and both sexes. The molecular diagnostic was performed based on a nPCR assay targeting the A. marginale msp5 gene. Anaplasma marginale prevalence was 63.8 % and the bacteria were detected in all the cantons studied. Thirteen representative strains were selected and genetically characterized based on the msp1α gene. Genetic diversity analysis revealed that different strains circulate in the bovine herds studied. The results suggest that cattle movement may contribute to the circulation of common strains in the area. The results demonstrate a high prevalence of A. marginale in the region which should be considered by the sanitary authorities. The epidemiological surveillance for this disease should increase to anticipate acute disease outbreaks with high mortality. Bovine anaplasmosis outbreaks can cause economic losses and the death of several animals; therefore, measures for the prevention and control of this disease are required.

Epidemiological survey of Anaplasma marginale in cattle and buffalo in Sri Lanka

Bovine anaplasmosis caused by Anaplasma marginale represents a serious threat to cattle farming worldwide, especially in the tropics and subtropics. In the present study, archived DNA samples from the blood of cattle (n=437) in the Nuwara Eliya, Galle, Ampara, Polonnaruwa, and Jaffna districts and buffalo (n=327) in the Galle, Polonnaruwa, Mannar, and Mullaitivu districts in Sri Lanka, were screened for A. marginale using a major surface protein 5 (msp5) gene-based PCR assay. The findings showed that 32.7 and 57.5% of cattle and buffalo, respectively, were A. marginale-positive. The rate of positivity differed significantly among geographical regions. In conclusion, the high rates of A. marginale infection in cattle and buffalo highlight the importance of effective control measures in Sri Lanka.