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

Abstract

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.

Prevalence and Risk Factors of Anaplasmosis in Simmental Cattle in the Peruvian Amazon

“…According to sex, prevalence was similar in female cattle (67.7%) than in male cattle (64.8%); therefore, no statistically significant differences were found ( Table 1 ). In a study under similar feeding conditions, the prevalence of A. marginale in cows was 59.5%, which was lower than the values found in this study [ 27 ]. These results differ with the study by Sisson et al [ 10 ], which mentions that males are more likely to be infected by A. marginale or A. centrale , due to the significant suppressive effect of testosterone on immune function in a variety of mammal species including cattle [ 28 ].…”

Characterization of strains of Anaplasma marginale from clinical cases in bovine using major surface protein 1a in Uruguay

“…These results are consistent with previous results for strains found mainly in Brazil ( 19 , 20 , 38 ), Argentina ( 18 ) and Colombia ( 39 ). Other genotypes frequently observed in our work were G and H. Studies carried out in Brazil (São Paulo and Maranhão) reported that genotype H was the most frequently found in beef and dairy cattle ( 21 , 22 ). However, the genetic diversity of circulating strains in the equatorial zone, comprising the countries of Ecuador, Mexico, Cuba, and subtropical countries such as South Africa and the USA, are different, with G and C being the main genotypes ( 15 , 27 , 40 ).…”