New research suggests the antibiotic cocktail of penicillin and streptomycin may encourage the spread of malaria, the sometimes-deadly, flu-like disease.
Scientists at the Imperial College London found that when mosquitoes drank blood carrying the two antibiotics they became more susceptible to the parasite that causes malaria -- thus more likely to spread the infection to humans.
Just as antibiotics augment the microbiome of the human gut, penicillin- and streptomycin-laced blood disrupt the guts of mosquitoes and diminish the insects' defenses against disease-causing parasitic protozoans.
Antibiotics, of course, have been crucial to combating a variety of diseases in the developing world -- places where malaria remains a sizable problem. In addition to being used for the treatment or prevention of malaria itself, antibiotics are prescribed for well-known diseases like HIV and tuberculosis, as well as lesser-known tropical diseases like trachoma, yaws and filariasis.
But the new study suggests some antibiotics could be doing undue harm by encouraging the spread of malaria. Still, more research is needed before scientists and policy makers consider changes to drug programs in regions with high malarial activity.
"We only looked at two antibiotics in our study, so this is early stage research and we don't know what it means for other antibiotics -- it's possible other antibiotics might have no effect, or that they might make it harder for mosquitoes to transmit malaria," explained Dr. Mathilde Gendrin, lead author of the new study. "We would like to see much more research carried out to further understand our findings and to explore how other antibiotics might affect bacteria in the guts of mosquitoes."
"Ultimately, we hope that understanding any hidden effects of different antibiotics would mean we can combat the spread of malaria more effectively," said George Christophides, the director of life sciences research at Imperial College London. "For example, if particular antibiotics make mosquitoes more able to transmit malaria, the use of these could be combined with supply of bed nets in order to reduce mosquito bites."
The new research, which was published in the journal Nature, arrives alongside another new mosquito study that suggests a hybrid "super bug" mosquito in Mali has developed resistance to insecticides from exposure to treated mosquito nets.