A term we heard a bunch at the Emory Microbiome Symposium in November was â€œmetagenomicsâ€. Time for an explainer, with some help from Emory geneticist Tim Read.
Nature Reviews Microbiology defines metagenomics as â€œgenomic analysis of microbial DNA that is extracted directly from communities in environmental samples.â€
This technology â€” genomics on a huge scale â€” enables a survey of the different microorganisms present in a specific environment, such as water or soil, to be carried out. Metagenomics is also emerging as a tool for clinical diagnosis of infectious diseases.
Read notes that the term specifically refers to â€œshotgunâ€ sequencing of environmental DNA.
â€œThe shotgun approach is to randomly sample small pieces of the DNA in the tube, no matter which organism they came from,â€ he says. â€œThe output is a mÃ©lange of different genes from bacteria, viruses, fungi, plants and humans.Â The data is fascinating but the analysis is daunting.â€ Read more
In recent years public health authorities have raised concern that many strains of Chlamydia trachomatis, a bacterium that is the most common cause of sexually transmitted infections around the world, can be missed by conventional genetic tests. A mutation in part of its genomc can make Chlamydia undetectable by the most commonly used tests.
The Chlamydia tests are performed in a microfluidic cassette platform and data is returned about an hour after sample collection. In comparison, standard tests take a day or longer.
Most infections are asymptomatic but left untreated, Chlamydia infection can lead to pelvic inflammatory disease, infertility and ectopic pregnancy. It is also a Ray Ban online leading cause of blindness in developing countries.
Microbial geneticist Tim Read at Emory has been collaborating with Deborah Dean at Children’s Hospital Oakland and the Massachusetts firm NetBio to develop a fast, accurate and sensitive genetic test for Chlamydia.
“We used tools that were developed initially to answer basic scientific questions,” Read says. “We compared multiple genomes of C. trachomatis to find targets that would work across a broad selection of bacterial strains.”