Disrupted gut microbiome makes children more susceptible to amoebic dysentery

August 17, 2017

Children with lower diversity of microbial species in their intestines are more susceptible to severe infection with the Entamoeba histolytica parasite, according to a new study published in PLOS Pathogens.

E. histolytica is an amoeba that typically spreads via food, water, or hands that have been contaminated with feces. Some infected people have no symptoms, but others experience symptoms of varying severity, from mild abdominal symptoms to life-threatening disease. The factors that influence severity are unclear, but previous studies suggest an important role for the gut microbiome.

In the new study, Koji Watanabe of the University of Virginia and colleagues collected and analyzed stool samples from children in an urban slum in Dhaka, Bangladesh. They found that children who experienced colon inflammation because of E. histolytica infection had lower diversity of microbes in their stool than children with asymptomatic infection.

To better understand these findings, the researchers used antibiotics to disrupt the gut microbiome in mice. They then exposed the mice to E. histolytica to see whether they were more susceptible to infection. The researchers found that mice treated with antibiotics had more severe colon inflammation than untreated mice.

Mouse tissue and gene expression analysis showed that disruption of the gut microbiome decreased the activity of infection-fighting white blood cells known as neutrophils. The surface of neutrophils in these mice had lower amounts of a protein known as CXCR2 than in untreated mice. CXCR2 plays a role in the recruitment of neutrophils to fight infection in the gut, so decreased CXCR2 levels likely resulted in the observed decreased neutrophil activity.

The analysis also showed that disruption of the mouse gut microbiome decreased production of a protein known as interleukin-25, which aids the function of the mucosal barrier that acts as the intestine's first line of defense against infection.

These findings suggest a molecular mechanism by which disruption of the gut microbiome increases severity of E. histolytica infection, but further research will be needed to determine if similar molecular effects occur in humans. Meanwhile, the finding that disruption of the mouse gut microbiome can interfere with neutrophil activity may be of broader interest in research of other infectious diseases.


Related Infection Articles from Brightsurf:

Halving the risk of infection following surgery
New analysis by the University of Leeds and the University of Bern of more than 14,000 operations has found that using alcoholic chlorhexidine gluconate (CHG) halves the risk of infection in certain types of surgery when compared to the more commonly used povidone-iodine (PVI).

How plants shut the door on infection
A new study by an international team including University of Maryland scientists has discovered the key calcium channel responsible for closing plant pores as an immune response to pathogen exposure.

Sensing infection, suppressing regeneration
UIC researchers describe an enzyme that blocks the ability of blood vessel cells to self-heal.

Boost to lung immunity following infection
The strength of the immune system in response to respiratory infections is constantly changing, depending on the history of previous, unrelated infections, according to new research from the Crick.

Is infection after surgery associated with increased long-term risk of infection, death?
Whether experiencing an infection within the first 30 days after surgery is associated with an increased risk of another infection and death within one year was the focus of this observational study that included about 660,000 veterans who underwent major surgery.

Revealed: How E. coli knows how to cause the worst possible infection
The discovery could one day let doctors prevent the infection by allowing E. coli to pass harmlessly through the body.

UK study shows most patients with suspected urinary tract infection and treated with antibiotics actually lack evidence of this infection
New research presented at this week's European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Amsterdam, Netherlands (April 13-16, 2019) shows that only one third of patients that enter the emergency department with suspected urinary tract infection (UTI) actually have evidence of this infection, yet almost all are treated with antibiotics, unnecessarily driving the emergence of antimicrobial resistance.

Bacteria in urine doesn't always indicate infection
Doctors should think carefully before testing patients for a urinary tract infection (UTI) to avoid over-diagnosis and unnecessary antibiotic treatment, according to updated asymptomatic bacteriuria (ASB) guidelines released by the Infectious Diseases Society of America (IDSA) and published in Clinical Infectious Diseases.

Subsidies for infection control to healthcare institutions help reduce infection levels
Researchers compared three types of infection control subsidies and found that under a limited budget, a dollar-for-dollar matching subsidy, in which policymakers match hospital spending for infection control measures, was the most effective at reducing the number of hospital-acquired infections.

Dengue virus infection may cause severe outcomes following Zika virus infection during pregnancy
This study is the first to report a possible mechanism for the enhancement of Zika virus progression during pregnancy in an animal model.

Read More: Infection News and Infection Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.