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BRIEF RESEARCH REPORT article

Front. Water
Sec. Environmental Water Quality
Volume 6 - 2024 | doi: 10.3389/frwa.2024.1466377
This article is part of the Research Topic Microbial Source Tracking (MST) tools to identify the origins of fecal pollution in environmental water resources and the impact of microbial contaminants on human health View all articles

Large, but short-term, increase in fecal indicator bacteria following extreme flooding from Hurricane Harvey

Provisionally accepted
Maitreyee Mukherjee Maitreyee Mukherjee 1*Md Shakhawat Hossain Md Shakhawat Hossain 2John Boswell John Boswell 3Michael G. LaMontagne Michael G. LaMontagne 4Terry Gentry Terry Gentry 3*
  • 1 Eastern Michigan University, Ypsilanti, Michigan, United States
  • 2 Tarleton State University, Stephenville, Texas, United States
  • 3 Texas A and M University, College Station, Texas, United States
  • 4 University of Houston–Clear Lake, Houston, Texas, United States

The final, formatted version of the article will be published soon.

    Hurricane Harvey caused widespread flooding along the Texas Gulf Coast in August 2017; some areas of Houston received >150 cm of rainfall within a few days. Due to concerns over fecal contamination of floodwaters, surface water samples were collected at six locations in the southeastern Houston area immediately before and after the hurricane and then every one to two weeks thereafter over a two-month period. Total E. coli was enumerated using the IDEXX Quanti-Tray/2000 system. DNA extracted from water samples was analyzed via quantitative real-time PCR (qPCR) for general and source-specific total Bacteroidales and human Bacteroidales markers, and digital PCR (dPCR) for antibiotic resistance genes (ARG) and a plasmid (pBI143) associated with human waste. SourceTracker2 was used to determine human source contributions based on metagenomic analysis of PCR-amplified 16S rRNA gene fragments. Samples collected immediately after the hurricane had elevated levels of E. coli, ranging from 488 to 1,733 CFU 100 ml-1. After one week, E. coli levels decreased to <100 CFU 100 ml-1. Total Bacteroidales numbers were elevated immediately following the hurricane and remained high for twelve days. Human-source contributions, as assessed by PCR methods and metagenomic analysis, peaked within twelve days after the hurricane consistently across all sampling sites. Multiple regression analysis of environmental parameters, copies of ARG and pBI143, and metagenomic data confirmed that human waste caused the dramatic, short-term, high levels of fecal contamination of floodwaters generated by Hurricane Harvey. Fecal indicators approached normal background levels approximately three weeks after the rainfall ended.

    Keywords: E. coli, fecal indicator bacteria, coliform, Hurricane, Harvey, NMDS, pBI143

    Received: 17 Jul 2024; Accepted: 18 Oct 2024.

    Copyright: © 2024 Mukherjee, Hossain, Boswell, LaMontagne and Gentry. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Maitreyee Mukherjee, Eastern Michigan University, Ypsilanti, 48197, Michigan, United States
    Terry Gentry, Texas A and M University, College Station, 77843, Texas, United States

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