Coxiella burnetii, the agent of Q fever in Brazil: its hidden role in seronegative arthritis and the importance of molecular diagnosis based on the repetitive element IS1111 associated with the transposase gene

Tatiana Rozental,Grasiely Souza Mattos,Elba Regina Sampaio De Lemos,Alexsandra Rm Favacho,Ronaldo Rozenbaum,Raphael Gomes,Luis Filipe Mascarenhas,Daniele Nunes Almeida,Cecília Carlos Magno,Maria Inês Doria Rossi

doi:10.1590/s0074-02762012000500021

Abstract

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.

Highlights

Q fever is caused by Coxiella burnetii, a small obligate intracellular Gram-negative bacterium of the order Legionellales (Stein et al 1993)
Impaired T-cell immunity in patients with human im m u n o d e f i c ie n c y v i r u s ( H I V ), c a n c e r, l y m p h o ma and pregnancy has been associated with the failure to eradicate C. burnetii and progression to the chronic disease, there are no previous reports of an association between Q fever and the use of methotrexate (MTX) for immunosuppressive therapy (Maurin & Raoult 1999, Nausheen & Cunha 2007)
The C. burnetii DNA sequences were detected by polymerase chain reaction (PCR) performed on the serum and bronchoalveolar lavage (BAL) samples collected on day 7 of the illness, using the primers QBT-1 (5’-TATGTATCCACCGTAGCCAGC-3’) and QBT-2 (5’-CCCAACAACACCTCCTTATC-3’), which amplify a 687 bp fragment of the repetitive element IS1111 of a heat shock protein gene (Hoover et al 1992)

Summary

Introduction

Q fever is caused by Coxiella burnetii, a small obligate intracellular Gram-negative bacterium of the order Legionellales (Stein et al 1993). Impaired T-cell immunity in patients with human im m u n o d e f i c ie n c y v i r u s ( H I V ), c a n c e r , l y m p h o ma and pregnancy has been associated with the failure to eradicate C. burnetii and progression to the chronic disease, there are no previous reports of an association between Q fever and the use of methotrexate (MTX) for immunosuppressive therapy (Maurin & Raoult 1999, Nausheen & Cunha 2007).

Results

Conclusion