High prevalence of Anaplasma marginale in the Crioula Lageana cattle

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.

Epidemiological assessment of Anaplasma marginale, Babesia bigemina, and Babesia bovis infections in Colombian creole cattle breeds: A molecular survey in northeastern Colombia

Anaplasmosis and babesiosis are globally distributed arthropod-borne diseases known for causing substantial economic losses due to their high morbidity and mortality rates. This study aims to assess the frequency and epidemiological features associated with the infection of Anaplasma marginale, Babesia bigemina, and Babesia bovis in three Creole cattle breeds (Chino Santandereano (Chino), Casanareño (CAS), and Sanmartinero (SM)) in northeastern Colombia. Between June 2019 and March 2020, a total of 252 Creole cattle were sampled, with Chino, CAS, and SM accounting for 42.8%, 29.5%, and 29.5% of the samples, respectively. Blood samples were subjected to molecular analysis to detect the DNA of A. marginale, B. bigemina, and B. bovis, using species-specific primers. Additionally, Packed Cell Volume (PCV), total serum proteins, and body condition were evaluated. Molecular analyses revealed the presence of B. bigemina, A. marginale, and B. bovis in 83.7% (211/252; 95% CI = 79.1%-88.3%), 59.9% (151/252; 95% CI = 53.8%-66.1%), and 40.9% (103/252; 95% CI = 34.7%-46.9%) of the samples, respectively, with 69% (174/252; 95% CI = 57.8%-80.3%) exhibiting coinfections. Notably, in infected animals, no significant alterations in PCV, total serum proteins, or body condition were observed. Multivariate analyses indicated a statistically significant association between the frequency of A. marginale infection and the breed and season, with a higher frequency in SM during the rainy season (P < 0.05). To our knowledge, this is the first molecular survey that evaluates multiple arthropod-borne pathogens in Colombian Creole breeds. The results revel a high frequency of B. bigemina and A. marginale infections, coupled with a notable frequency of coinfections, all without significant alteration in the PCV, total serum proteins and body conditions. Our findings enhance the understanding of the epidemiological aspects of arthropod-borne pathogens in Colombian Creole breed and contribute to the improvement of sanitary programs for these animals.

Identification of Anaplasma marginale, Babesia bovis and Babesia bigemina resistance alleles in Crioulo Lageano cattle using PCR-SBT and BoLA-DRB3 gene sequencing

Introduction

The BoLA-DRB3 gene in cattle is associated with tolerance to several infectious diseases, such as neosporosis, dermatophilosis, leukosis, and mastitis.

Methods

This study used PCR-SBT and BoLA-DRB3 gene sequencing to determine the association between the presence or absence of Anaplasma marginale, Babesia bovis, and Babesia bigemina infections in 208 Crioulo Lageano cattle and alleles present in the population. The chi-square test and odds ratio analysis were employed to establish the association.

Results

Of the BoLA-DRB3 gene alleles present in the population, two alleles were significantly associated with resistance to A. marginale infections: BoLA-DRB3001:01 (p < 0.001; OR = 0.224), which had a frequency of 7.93%, and BoLA-DRB3024:06 (p = 0.007; OR < 0.00001), which had a frequency of 0.72%. Regarding B. bovis infection, the BoLA-DRB3*011:01 allele (p = 0.002; OR = 0.271) had a frequency of 6% in the population and was associated with resistance to the infection. None of the alleles was associated with resistance to infection by B. bigemina.

Discussion

The Crioulo Lageano breed has alleles that may confer resistance against infection by A. marginale and B. bovis.

Prevalence of natural infection by Trypanosoma evansi in Crioula LAGEANA cattle

Cattle trypanosomiasis negatively impacts animal husbandry due to high morbidity, productivity losses, and mortality rates. Knowledge regarding Trypanosoma evansi infections in locally adapted breeds remains limited. Some cattle breeds exhibit trypanotolerance, requiring the determination of prevalence, as well as related tolerance and resistance characteristics, for disease control programs. This study aimed to determine T. evansi prevalence in Crioula Lageana cattle and associate clinical, hematological, and biochemical aspects with the infection to further research on tolerance in this population. Blood samples from 310 Crioula Lageana cattle were tested using Polymerase Chain Reaction (PCR) and Indirect Immunofluorescence Reaction (IIFR). T. evansi prevalence was 8% (24/310) using PCR and 4% (11/310) using IIFR. Positive animals showed increased ruminal movements, elevated eosinophil counts, and reduced monocyte numbers, but both latter within the reference range for the species. Albumin concentrations were low in positive cases and remained below the reference range limit for both groups. However, triglycerides exceeded the physiological range for the species in both positive and negative groups. Increased gamma-glutamyltransferase (GGT) activity was observed in positive animals. In conclusion, Crioula Lageana cattle exhibited enzootic instability with a low T. evansi infection prevalence when assessed using PCR and IIFR techniques. Furthermore, the animals did not display clinical, hematological, or biochemical alterations attributable to the presence of hemoparasites.

First report on molecular surveillance based on duplex detection of Anaplasma marginale and Theileria annulata in dairy cattle from Punjab, Pakistan

Theileriosis and anaplasmosis are important tick-borne hemoparasites of bovines. The first surveillance study aimed to assess the suitability of duplex PCR for simultaneous detection of Theileria annulata and Anaplasma marginale field infections in Jhang and Rawalpindi districts of Punjab, Pakistan. Cattle blood samples (n = 480) were collected from selected union councils of all tehsils using a multistage sampling technique. The sampling unit consisted of asymptomatic cattle belonging to either age, sex, and breed. Epidemiological data related to host, area, management, and season were collected using a questionnaire. Based on duplex PCR, the overall prevalence of the two concurrent tick-borne pathogens was 19.79% (95/480). Chi-square analysis indicated that age, breed, tick infestation, history of tick-borne diseases, frequency of acaricidial application, and season were significantly associated with tick-borne pathogens. Phylogenetic analysis of A. marginale and T. annulata isolates based on msp1β and cytochrome b genes, respectively, revealed that nucleotide sequences acquired from these two pathogens are novel, grouped separately from different countries. All our A. marginale isolates showed 88.2 to 80.5% similarity with isolates from Egypt, Israel, Mexico, and lesser homology with South African isolates. Similarly, the phylogenetic tree based on cytochrome b partial sequences of T. annulata revealed that our sequences are closer to those from India and Iran. Based on this first study on concomitant detection of tick-borne pathogens, it can be concluded that mixed infections are endemic in the study districts and mPCR is suitable for detecting concurrent field infections. Simultaneous infections should be considered while performing surveillance and chemotherapeutic trials for better prevention and control of tick-borne diseases.

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.