Translational research about infection by Bartonella henselae and its transfusion transmission

Author(s)

Marilene Neves da Silva

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2016-05-30

Examining board members

Paulo Eduardo Neves Ferreira Velho; Alexsandra Rodrigues de Mendonça Favacho; Aline Aparecida Buriola; Angélica Zaninelli Schreiber; Renata Fagnani

• Advisor: Paulo Eduardo Neves Ferreira Velho; Amanda Roberta de Almeida

Abstract

Bartonella is a genus of Gram-negative, microaerophilic and fastidious bacteria that are potentially fatal. Cats and dogs are reservoirs of known species of these agents using blood sucking arthropods as vectors. Bartonella is the only bacterium that infects the inside of human erythrocytes and asymptomatic infection of blood donors has been reported. With the aim of studying the B. henselae infection in mice as a translational model, transmission via blood transfusion and acute and late infection of the blood, spleen, liver and skin of animals were evaluated. In the first study BALB / c mice were inoculated intraperitoneally with suspension of B. henselae. After 96 hours the animals were euthanized and liver, spleen and blood samples were collected. Thirty microliters of blood from the B. henselae inoculated animals were transfused by ocular plexus to a new group of animals. Infection with B. henselae was investigated by conventional and nested PCR and was positive by nested PCR in spleen and liver of animals inoculated intraperitoneally, even when their blood samples were negative. DNA of the bacterium was detected in half of spleen samples from the blood transfused animals. The injected blood samples were from the B. henselae intraperitoneally inoculated mice but had negative blood PCRs. B. henselae transmission by blood transfusion is possible in mice, even when donors have not detectable blood infection. In the second experiment, confocal microscopy and the same molecular tests were used to demonstrate the B. henselae infection in blood, skin, liver and spleen of mice that were of the same strain. Samples were evaluated at 4 and 21 days after intraperitoneal experimental infection. The DNA of the bacterium was detected only in the tissue of some animals euthanized at 4 days and the blood of all animals euthanized at 21 days. Negative molecular results in blood not exclude the possibility of infection with B. henselae in mice. The late onset of the infection in the blood can be another challenge for diagnosis infection by the bacteria, especially in early diagnosis. The results reinforce the need for a reassessment of the risks and the impact of transmission of B. henselae through blood transfusions (AU)

• FAPESP's process: 12/22340-5 - Non-invasive methodologies with enhanced sensitivity for diagnosing human Bartonella spp. infection
• Grantee: Marilene Neves da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate