Genetic modifications are introduced into bacteria to control Anaplasma phagocytophilum infection in ticks

    IREC researchers have developed modified bacteria using molecular biotechnology that express Anaplasma phagocytophilum proteins capable of competing with this pathogen and reducing infection

    Tick microbiota can be targeted for the control of tick-borne diseases such as human granulocytic anaplasmosis (HGA), caused by the pathogen Anaplasma phagocytophilum.

    The term "Frankenbacteriosis”, inspired by the fictional character made up of different human parts, has been defined in this research as paratransgenesis of tickssymbiotic/commensal bacteria, in this case of the genus Sphingomonas, to mimic and compete with tick-borne pathogens. Para-transgenesis is a molecular biology technique that attempts to eliminate a pathogen from vector populations through transgenesis (insertion of DNA genetic material of interest into a recipient organism) of a vector symbiont.

    Anaplasma phagocytophilum in ticks


    Using metaproteomics, the bacterial genera of the tick microbiota that competed with the pathogen A. phagocytophilum were identified. In this way, Sphingomonas (FrankenSphingomonas) bacteria were modified to produce the A. phagocytophilum MSP4 protein on their surface.

    First, interactions between Anaplasma phagocytophilum and symbiotic Sphingomonasidentified by metaproteomics analysis in the gut of the vector Ixodes scapularisshowed competition between both bacteria. Consequently, scientists from the Research Group in Health and Biotechnology (SaBio)of the Instituto de Investigación en Recursos Cinegéticos (IREC – CSIC, UCLM, JCCM), in collaboration with scientists from other institutions, selected Sphingomonasas a target of para-transgenesis for the control of infection and transmission of Anaplasma phagocytophilum. Among other candidates, the Anaplasma protein MSP4 was chosen for its important role in interactions with host cells during infection. The genetic material coding for this protein was inserted into the Sphingomonas bacteria thus they would produce this protein on their surface.

    The results showed that the bacteria FrankenSphingomonas expressing the major surface protein 4 (MSP4) of Anaplasma phagocytophilum (Frankensphingomonas-MSP4) and were co-infected with the pathogen in cells or rodents, mimicked the presence of the pathogen and reduced infection levels in ticks by competition and interaction with the cellular receptor components of the infection.

    Transstadial (between life stages) and transovarial (to offspring) transmission of FrankenSphingomonas-MSP4 suggests that tick larvae containing these Sphingomonas Genetically modified cells could be produced under laboratory conditions and released abroad to compete and replace unmodified populations along with an associated reduction in infection and pathogen transmission and risks of human granulocytic anaplasmosis.

    Anaplasma phagocytophilum in ticks


    Co-infection of FrankenSphingomonas-MSP4 and A. phagocytophilum in tick or human and rodent cells reduces infection of the pathogen in vitro and in vivo.

    The methodology and protocols developed to carry out the genetic modifications of the bacterial genus Sphingomonas and express in them the proteins of Anaplasma phagocytophilum have been chosen by the journal STAR protocols, from Cell Press, to be published soon individually as a reference protocol for this technique (

    The scientific publication of this research is available at: