Gut microbes influence fitness and malaria transmission potential of Asian malaria vector Anopheles stephensi

Sharma, Anil; Dhayal, Devender; Singh, O. P.; Adak, T.; Bhatnagar, Raj K.

doi:10.1016/j.actatropica.2013.06.008

Cited by 44 publications

(27 citation statements)

References 49 publications

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“…By a general mechanism known as colonization resistance (87)(88)(89), members of the gut microbiota are thought to antagonize pathogens. Production of bacteriocidins or peroxidases can inhibit or kill pathogenic bacteria.…”

Section: Figmentioning

confidence: 99%

Giardia Alters Commensal Microbial Diversity throughout the Murine Gut

et al. 2017

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Giardia lamblia is the most frequently identified protozoan cause of intestinal infection. Over 200 million people are estimated to have acute or chronic giardiasis, with infection rates approaching 90% in areas where Giardia is endemic. Despite its significance in global health, the mechanisms of pathogenesis associated with giardiasis remain unclear, as the parasite neither produces a known toxin nor induces a robust inflammatory response. Giardia colonization and proliferation in the small intestine of the host may, however, disrupt the ecological homeostasis of gastrointestinal commensal microbes and contribute to diarrheal disease associated with giardiasis. To evaluate the impact of Giardia infection on the host microbiota, we used culture-independent methods to quantify shifts in the diversity of commensal microbes throughout the gastrointestinal tract in mice infected with Giardia. We discovered that Giardia's colonization of the small intestine causes a systemic dysbiosis of aerobic and anaerobic commensal bacteria. Specifically, Giardia colonization is typified by both expansions in aerobic Proteobacteria and decreases in anaerobic Firmicutes and Melainabacteria in the murine foregut and hindgut. Based on these shifts, we created a quantitative index of murine Giardia-induced microbial dysbiosis. This index increased at all gut regions during the duration of infection, including both the proximal small intestine and the colon. Giardiasis could be an ecological disease, and the observed dysbiosis may be mediated directly via the parasite's unique anaerobic fermentative metabolism or indirectly via parasite induction of gut inflammation. This systemic alteration of murine gut commensal diversity may be the cause or the consequence of inflammatory and metabolic changes throughout the gut. Shifts in the commensal microbiota may explain observed variations in giardiasis between hosts with respect to host pathology, degree of parasite colonization, infection initiation, and eventual clearance.KEYWORDS Giardia, microbiome, parasite, pathogenesis G iardia lamblia is a microaerophilic protozoan parasite of humans and animals that causes significant morbidity and diarrheal disease worldwide (1, 2). Giardiasis is a zoonotic disease with diverse animal reservoirs. Parasites infect and complete their life cycle in mammalian hosts, and infected animals shed Giardia cysts into water supplies. Over 200 million people are estimated to have acute or chronic giardiasis, and rates of giardiasis approach 90% in areas where it is endemic (3, 4). When prevalent, giardiasis has been implicated as a primary cause of growth restriction for children, resulting in long-term consequences, such as stunting, failure to thrive, malnutrition, and cognitive disabilities (1, 2, 5). In addition, Giardia has been associated with substantial postclearance irritable bowel symptoms in both children and adults (1, 6-8). The significant and adverse impact of giardiasis on global human health contrasts with a considerable lack of resea...

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Section: Figmentioning

confidence: 99%

Giardia Alters Commensal Microbial Diversity throughout the Murine Gut

et al. 2017

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“…By a general mechanism known as “colonization resistance” (103-105), gut microbiota are thought to antagonize pathogens. Production of bacteriocidins or peroxidases can inhibit or kill pathogenic bacteria.…”

Section: Discussionmentioning

confidence: 99%

Giardiaalters commensal microbial diversity throughout the murine gut

Barash

Maloney

Singer

et al. 2016

Preprint

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Giardia lamblia is the most frequently identified protozoan cause of intestinal infection. Over one billion people are estimated to have acute or chronic giardiasis, with infection rates approaching 90% in endemic areas. Despite its significance in global health, the mechanisms of pathogenesis associated with giardiasis remain unclear as the parasite neither produces a known toxin nor induces a robust inflammatory response. Giardia colonization and proliferation in the small intestine of the host may, however, disrupt the ecological homeostasis of gastrointestinal commensal microbes and contribute to diarrheal disease associated with giardiasis. To evaluate the impact of Giardia infection on the host microbiota, we use culture-independent methods to quantify shifts in the diversity of commensal microbes throughout the entire gastrointestinal tract in mice infected with Giardia. We discovered that Giardia’s colonization of the small intestine causes a systemic dysbiosis of aerobic and anaerobic bacterial taxa. Specifically, giardiasis is typified by both expansions in aerobic Proteobacteria and decreases in anaerobic Firmicutes and Melainabacteria in the murine foregut and hindgut. Based on these shifts, we created a quantitative index of murine Giardia-induced microbial dysbiosis. This index increased at all gut regions during the duration of infection, including both the proximal small intestine and the colon. Thus giardiasis could be an ecological disease, and the observed dysbiosis may be mediated directly via the parasite’s unique anaerobic fermentative metabolism or indirectly via parasite induction of gut inflammation. This systemic alteration of murine gut commensal diversity may be the cause or the consequence of inflammatory and metabolic changes throughout the gut. Shifts in the commensal microbiota may explain observed variation in giardiasis between hosts with respect to host pathology, degree of parasite colonization, infection initiation, and eventual clearance.

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“…In the case of Anopheles stephensi, gut sanitized mosquitoes were found to have reduced longevity and fecundity (Sharma et al, 2013). In the case of Ae.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of midgut microflora and dengue virus impact on life history traits in Aedes aegypti

et al. 2014

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Significant morbidity and potential mortality following dengue virus infection is a re-emerging global health problem. Due to the limited effectiveness of current disease control methods, mosquito biologists have been searching for new methods of controlling dengue transmission. While much effort has concentrated on determining genetic aspects to vector competence, paratransgenetic approaches could also uncover novel vector control strategies. The interactions of mosquito midgut microflora and pathogens may play significant roles in vector biology. However, little work has been done to see how the microbiome influences the host's fitness and ultimately vector competence. Here we investigated the effects of the midgut microbial environment and dengue infection on several fitness characteristics among three strains of the primary dengue virus vector mosquito Aedes aegypti. This included comparisons of dengue infection rates of females with and without their normal midgut flora. According to our findings, few effects on fitness characteristics were evident following microbial clearance or with dengue virus infection. Adult survivorship significantly varied due to strain and in one strain varied due to antibiotic treatment. Fecundity varied in one strain due to microbial clearance by antibiotics but no variation was observed in fertility due to either treatment. We show here that fitness characteristics of Ae. aegypti vary largely between strains, including varying response to microflora presence or absence, but did not vary in response to dengue virus infection.

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Gut microbes influence fitness and malaria transmission potential of Asian malaria vector Anopheles stephensi

Cited by 44 publications

References 49 publications

Giardia Alters Commensal Microbial Diversity throughout the Murine Gut

Giardia Alters Commensal Microbial Diversity throughout the Murine Gut

Giardiaalters commensal microbial diversity throughout the murine gut

Dynamics of midgut microflora and dengue virus impact on life history traits in Aedes aegypti

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