Coxiella burnetii is the agent of Q fever , an emergent worldwide zoonosis of wide clinical spectrum. Although C. burnetii infection is typically associated with acute infection, atypical pneumonia and flu-like symptoms, endocarditis, osteoarticular manifestations and severe disease are possible, especially when the patient has a suppressed immune system; however, these severe complications are typically neglected. This study reports the sequencing of the repetitive element IS1111 of the transposase gene of C. burnetii from blood and bronchoalveolar lavage (BAL) samples from a patient with severe pneumonia following methotrexate therapy, resulting in the molecular diagnosis of Q fever in a patient who had been diagnosed with active seronegative polyarthritis two years earlier. To the best of our knowledge, this represents the first documented case of the isolation of C. burnetii DNA from a BAL sample.

A dinâmica da infecção de B. bovis no carrapato-vetor B. microplus foi estudada em condições laboratoriais na Universidade Federal Rural do Rio de Janeiro no Laboratório de Protozoologia. Para tanto, foram examinadas 100 fêmeas ingurgitadas que se desprenderam naturalmente do hospedeiro vertebrado, sendo que 84 fêmeas apresentaram-se infectadas com esporocinetos de B. bovis, com a seguinte distribuição: 39%, 33%, e 12% nos dias 3, 4 e 5 de incubação, respectivamente. Foram obtidas amostras de ovos provenientes das fêmeas positivas para B. bovis, 100% das amostras de ovos estavam infectadas, apresentado a seguinte distribuição: 46,4%, 34,5%, 16,7% e 2,4% nos dias 4, 5, 6 e 7 de incubação, respectivamente. As freqüências acumuladas, tanto de fêmeas infectadas (84%) quanto de ovos infectados (100%) mantiveram-se até o 17° dia de incubação. De acordo com as freqüências acumuladas e o aumento do grau de infecção, conclui-se que amostras coletadas a partir do 5° e 7° dia de incubação, são ideais para o diagnóstico de B. bovis, em hemolinfa e ovos, respectivamente.

The dynamics of B. bovis infections in the tick-vector B. microplus, was studied in laboratory conditions at Universidade Federal Rural do Rio de Janeiro in the Laboratory of Protozoology, Brazil.. To do it, 100 engorged females naturally droped from vertebrate host were examined. From this total 84 females showed infected with sporokinets of B. bovis, with the following distribution: 39%, 33% and 12% on days 3, 4 and 5 of incubation, respectivelly. Eggs samples were obtained from the positives ones to B. bovis females and 100% were infected, showed the follow distribution: 46.4%, 34.5%, 16.7% and 2.4% on days 4, 5, 6 and 7 of incubation, respectivelly. The accumulative frequencies, of infected females (84%) and infected eggs (100%), were kept until 17th days of incubation. According to the accumulatives frequencies and the increase of the degree of incubation, it was concluded that samples collect on days 5th to 7th of incubation, are the best for diagnosis of B. bovis in hemolymph and eggs, respectively.