ICMI 2015

F.75 THE IMPACT OF CO-INFECTION WITH CITROBACTER RODENTIUM ON MORTALITY AND MORBIDITY DURING EXPERIMENTAL MALARIA INFECTION

Friday, July 17, 2015
Grand Hall and Gallery, Ground Floor & 1st Floor (Maritim Hotel)
Luara Isabela Santos , University of Oxford, Oxford, United Kingdom
Suelen Diniz , UFMG, Belo Horizonte, Brazil
Ricardo Gazzinelli , UMASS, Worcester, MA
Lis Antonelli , FIOCRUZ, Belo Horizonte, Brazil
Kevin Maloy , University of Oxford, Oxford, United Kingdom
Malaria is an infectious disease caused by Plasmodium parasites and it is currently considered one of the greatest public health problems worldwide. Epidemiological evidence support the hypothesis that infection with malaria predisposes to infection and mortality from bacterial infections, as patients with concomitant malaria and bacteremia display three to eight times higher mortality than in individuals with malaria alone. However the mechanistic basis for how malaria infection predisposes to bacterial infection is not clear. Aim: To determine the effects of acute intestinal infection with Citrobacter rodentium on concomitant Plasmodium chabaudi infection. Methods: C57BL/6 mice were infected as follows: (1) P. chabaudi; (2) C. rodentium; (3) co-infection; (4) uninfected. The weight and parasitemia of animals were measured daily. Cohorts of each group were euthanized at 7, 14 and 21 days post-infection for collection of liver, spleen, colon, cecum and cecal contents. These were processed and plated to assess Citrobacter rodentium colonization and translocation. Results: Mice infected with P. chabaudi only or co-infected exhibited comparable weight loss with similar kinetics. However, significant mortality was observed in the co-infected group from day 8 post-infection, whereas all single infection groups showed 100% survival. In addition, on 14 post-infection, increased numbers of C. rodentium were found in the spleen, colon and cecum of some co-infected animals, compared to the group infected only by C. rodentium. Conclusion: Our data show that co-infection between P. chabaudi and C. rodentium increases morbidity and mortality of the host and suggest that this model could prove useful in identifying the mechanisms responsible.