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:
Posted by Dr. Tim Sandle,
Pharmaceutical Microbiology