Thursday, 13 September 2018

Hurricane Harvey samples saddled with antibiotic-resistant genes


Rice University scientists have released the first results of extensive water sampling in Houston after the epic flooding caused by Hurricane Harvey. They found widespread contamination by E. coli, likely the result of overflow from flooded wastewater treatment plants.

The microbial survey showed high levels of E. coli, a fecal indicator organism, trapped in homes that still contained stagnant water weeks after the storm, as well as high levels of key genes that indicate antibiotic resistance.

The study led by Rice environmental engineer Lauren Stadler appears in the American Chemical Society journal Environmental Science & Technology Letters. A pair of National Science Foundation RAPID grants helped the team collect and analyze samples.

Rice environmental engineers Stadler, Qilin Li and Pedro Alvarez and their students were on the front lines, even before Harvey subsided, to take samples from floodwaters near the overflowing Brays and Buffalo bayous, in public spaces and inside and outside residential homes to compare their microbial content. Samples of stagnant water were taken from homes that had been closed off for more than a week, while others were taken from homes that had floodwater flowing through them.

Early samples from each location carried elevated levels of E. coli. But most striking was the fact that sampled water and, later, sediment showed abundant levels of two indicator genes, sul1 and intI1, that mark the presence of antibiotic-resistant bacteria, even weeks after the flood. In particular, samples from floodwaters inside closed homes showed concentrations of sul1 were 250 times greater and intI1 60 times greater in than in bayou samples.

See:

Pingfeng Yu, Avery Zaleski, Qilin Li, Ya He, Kris Mapili, Amy Pruden, Pedro J. J. Alvarez, Lauren B. Stadler. Elevated Levels of Pathogenic Indicator Bacteria and Antibiotic Resistance Genes after Hurricane Harvey’s Flooding in Houston. Environmental Science & Technology Letters, 2018; DOI: 10.1021/acs.estlett.8b00329

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

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