Serologic Cross-Reactivity between Anaplasma marginale and Anaplasma phagocytophilum

Abstract

In the context of a serosurvey conducted on the Anaplasma marginale prevalence in Swiss cattle, we suspected that a serological cross-reactivity between A. marginale and A. phagocytophilum might exist. In the present study we demonstrate that cattle, sheep and horses experimentally infected with A. phagocytophilum not only develop antibodies to A. phagocytophilum (detected by immunofluorescent-antibody assay) but also to A. marginale (detected by a competitive enzyme-linked immunosorbent assay). Conversely, calves experimentally infected with A. marginale also developed antibodies to A. phagocytophilum using the same serological tests. The identity of 63% determined in silico within a 209-amino-acid sequence of major surface protein 5 of an isolate of A. marginale and one of A. phagocytophilum supported the observed immunological cross-reactivity. These observations have important consequences for the serotesting of both, A. marginale and A. phagocytophilum infection of several animal species. In view of these new findings, tests that have been considered specific for either infection must be interpreted carefully.

Molecular and serological evidence of Anaplasma phagocytophilum infection of farm animals in the Black Sea Region of Turkey

“…In addition, antigen crossreactivity between A. marginale and A. phagocytophilum has been demonstrated in infected animals (Dreher et al, 2005). Tick-transmitted diseases such as babesiosis, theileriosis and A. marginale infection, are known to occur in farm animals in the Black Sea Region of Turkey (Dincer et al, 1991;Karaer et al, 1997) and the animals used in the present study may also be infected with A. marginale or A. phagocytophilum as single or dual infection.…”

“…Serological investigation is therefore not reliable for some animals and before seroconversion appears as the only diagnostic tool to detect acute Anaplasma infection. In addition, morphological and serological methods are also unreliable to differentiate Anaplasma and Ehrlichia species due to morphological similarities and antigen cross-reactivity between species (Dreher et al, 2005). Therefore, a sensitive and specific technique such as PCR is required for the definitive diagnosis of A. phagocytophilum.…”

Comparação entre diversos antígenos para o diagnóstico de Anaplasma marginale por ELISA

“…Com relação aos testes que utilizaram MSP5 como antígeno (MSP5 e MIX), isso pode ser facilmente explicado devido ao fato dessa proteína ser conservada entre outras espécies de Anaplasma e Ehrlichia (Ndung'u et al 1995, Dreher et al 2005, Alleman et al 2006), e já existirem relatos de reações sorológicas cruzadas entre MSP5 de A. marginale e A. phagocytophilum em bovinos (Dreher et al 2005). Já com relação ao ELISA com MSP2, apesar de não existirem relatos sobre reações sorológi-cas cruzadas com outras espécies de Anaplasma, essa proteína apresenta ortólogos em todas as espécies conhecidas do gênero , Shkap et al 2002, Lin et al 2004, De La Fuente et al 2005.…”

Serological cross-reactivity between Anaplasma marginale and an Ehrlichia species in naturally and experimentally infected cattle

“…In a previous study, cattle experimentally infected with A. phagocytophilum tested positive using this cELISA test kit. 6 In another study, cross-reactivity was not demonstrated between human or dog antibodies to A. phagocytophilum and the recombinant MSP5 antigen of A. marginale when tested by cELISA. 25 However, cross-reactivity was evident when recombinant MSP5 antigens of A. phagocytophilum or A. marginale were incubated with heterologous sera using an indirect ELISA format.…”