Research Round-Up: Researchers track Leishmania parasite in Brazil; Europe and China have a high burden of traumatic brain injuries; Bacterium promotes development of colorectal cancer

Research Round-Up: Researchers track Leishmania parasite in Brazil; Europe and China have a high burden of traumatic brain injuries; Bacterium promotes development of colorectal cancer

Dogs, wild animals and sand flies in protected area in Brazil carry Leishmania parasite

Infected sand flies can transmit the Leishmania parasite through their bites, potentially leading to leishmaniasis, a parasitic infection that can be fatal to humans. This infection has primarily been identified in rural areas of the developing world, where people may be more exposed to sand flies and livestock that carry the parasite. However, the authors of a new study from PLOS Neglected Tropical Diseases found that more than 1 percent of dogs, as well as some opossums and insect species in an environmentally protected area in the major city of Campinas, southeastern Brazil, carry the parasite responsible for visceral leishmaniasis—the most dangerous form of leishmaniasis.

“Discussion concerning the participation of wild species in the transmission of zoonotic parasites has become particularly important in recent years… Anthropogenic changes in ecosystems are particularly important in this context, resulting in greater proximity between wild and domestic animals and humans,” the researchers say. “Investigating a new visceral leishmaniasis focus in all its distinct aspects contributes to our understanding of the key elements of the transmission dynamics and disease control.”

Europe and China have a high burden of traumatic brain injuries

Traumatic brain injuries (TBIs) are a serious public health risk posing a heavy burden for the EU and China, according to new research from PLOS Medicine. Researchers quantified the years of life lost as a result of suffering a TBI in the EU and the mortality risk from TBI in China, with the hope that measuring the burden of TBI might highlight the need for public policy makers to address this issue and take preventive action.

The researchers found that falls and traffic accidents were the leading causes of TBI in both the EU and China. “Future research should explore reasons for the particularly high risk of TBI mortality among particular populations, as well as for recent increases in certain subgroups,” the researchers say. “In particular, evidence-based prevention, response and treatment interventions for TBI… should be translated to Chinese culture and implemented nationwide.”

Bacterium promotes development of colorectal cancer

Previous studies have shown that people infected with a subspecies of the bacterium Streptococcus gallolyticus are more likely to have colorectal cancer, a leading cause of cancer death. A new study published in PLOS Pathogens shows that instead of just being associated with colorectal cancer, this bacterium may actively promote its development.

Researchers from the Texas A&M Health Science Center conducted several experiments using cultured human colorectal cells, mice with colorectal cancer and tissue from human tumors to investigate the precise role that this bacterium plays in the disease. They found that the bacterium promoted proliferation of colorectal cancer cells when they were grown in close proximity to each other, which suggests that it could play an active role in colorectal cancer cell development in humans. In future, the precise mechanisms of the bacterium’s tumor-promoting activity could potentially be exploited to develop new strategies to diagnose, prevent and treat colorectal cancer.

Image Credit: Laís Moraes Paiz, 2015.

Research Articles:

Donalisio MR, Paiz LM, da Silva VG, Richini-Pereira VB, von Zuben APB, Castagna CL, et al. (2017) Visceral leishmaniasis in an environmentally protected area in southeastern Brazil: Epidemiological and laboratory cross-sectional investigation of phlebotomine fauna, wild hosts and canine casesPLoS Negl Trop Dis 11(7): e0005666.

Majdan M, Plancikova D, Maas A, Polinder S, Feigin V, Theadom A, et al. (2017) Years of life lost due to traumatic brain injury in Europe: A cross-sectional analysis of 16 countries. PLoS Med 14(7): e1002331.

Kumar R, Herold JL, Schady D, Davis J, Kopetz S, Martinez-Moczygemba M, et al. (2017) Streptococcus gallolyticus subsp. gallolyticus promotes colorectal tumor developmentPLoS Pathog 13(7): e1006440.


Tessa is the Journal Media Manager at PLOS. She graduated from the University of California, Berkeley with degrees in Rhetoric and Music. She can be reached by email at and on Twitter at @tessagregs.

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