BUGS IN THE PIPES
The human microbiome, a collection of microorganisms living inside us and on our skin, has been attracting considerable attention. Now, researchers are discovering that the built environment also has a microbiome, which includes a community of potentially pathogenic bacteria living inside water supply pipes.
Georgia Tech doctoral student Maria Juliana Soto-Girón and School of Civil and Environmental Engineering Professor Kostas Konstantinidis are shown with images of bacteria. Research done with scientists from the U.S. Environmental Protection Agency documented bacteria in shower hoses taken from hospital patient rooms. Photo: John Toon
A paper published in the journal Applied and Environmental Microbiology described microbial communities found in shower hoses at a major U.S. hospital. The study documented bacteria — and related genes — using cutting-edge meta-genomic techniques that allow the characterization of organisms that cannot be detected using traditional culture-based microbiology assays.
Researchers from the U.S. Environmental Protection Agency and Georgia Tech collaborated to study these biofilm communities but can’t say yet if these bacteria pose a threat to patients. Because some of the genes could indicate pathogenic characteristics — such as resistance to antibiotics — more study is needed.
Image shows the growth of Mycobacterium isolated on a plate of culture medium. Photo: Stacey Pfaller, EPA
“We can say confidently that if pathogens are in there, they are not there in very high abundance,” said Kostas Konstantinidis, an associate professor in Georgia Tech’s School of Civil and Environmental Engineering. “But the organisms we detected in these biofilms appear to have characteristics that could be of interest because they are related to bacteria that are opportunistic pathogens that could pose a threat.”
Researchers began by culturing bacteria from 40 shower hoses removed from individual hospital rooms. Nucleic acid was extracted from five of the shower hoses and processed using next-generation sequencing technology. The sequencing data was sent to Georgia Tech, where doctoral student Maria Juliana Soto-Girón matched the sequences against known bacteria — and genes that have known effects such as virulence and antibiotic resistance.
“If they have a core of genes, they may be receptive to acquiring other genes that will render these microorganisms more problematic,” said Jorge Santo Domingo, a microbial ecologist with the EPA’s Office of Research and Development in Cincinnati. “These organisms are very good at living in difficult environmental conditions with limited carbon sources, so fighting them could become a challenging proposition. We don’t know if they constitute a problem, but we certainly want to find out.” — John Toon