Microbial source tracking and antimicrobial resistance in one river system of a rural community in Bahia, Brazil

Abstract Use of antibiotics inevitably leads to antimicrobial resistance. Selection for resistance occurs primarily within the gut of humans and animals as well as in the environment through natural resistance and residual antibiotics in streams and soil. We evaluated antimicrobial resistance in Gram negative bacteria from a river system in a rural community in Bahia, Brazil. Water was collected from the Jiquiriçá and Brejões rivers and the piped water supply. Additionally, stools were collected from a random sample of residents, cows, pigs and horses near the river. The samples were screened for bacteria resistant to ciprofloxacin, cefotaxime, and meropenem and identified biochemically at the genus and species levels. Microbial source tracking demonstrated that ruminant and human fecal contamination increased as the rivers neared the village center and decreased after the last residence. Antibiotic bacteria were identified from all samples (n = 32). No bacteria were resistant to carbapenems, but the majority of the enterobacteria were resistant to ciprofloxacin, even though this class of antibiotics is not commonly used in food animals in this region. Considering these facts, together with the pattern of human fecal contamination, a human source was considered most likely for these resistant isolates.

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0638 - Selecting microbial source tracking markers to identify fecal contamination from agricultural sources in Laguna Lake, Philippines

10.26226/morressier.5b5199bfb1b87b000ecef785 ◽

2018 ◽

Author(s):

Windell L. Rivera, PhD

Keyword(s):

Fecal Contamination ◽

Microbial Source Tracking ◽

Source Tracking ◽

Laguna Lake

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Investigating Sources of Fecal Contamination in Storm Drain Outfalls: Application of Genotypic Microbial Source Tracking

Proceedings of the Water Environment Federation ◽

10.2175/193864717822156497 ◽

2017 ◽

Vol 2017 (6) ◽

pp. 4813-4825

Author(s):

Darshan Baral ◽

Xu Li ◽

David Admiraal ◽

Bruce Dvorak

Keyword(s):

Fecal Contamination ◽

Microbial Source Tracking ◽

Source Tracking ◽

Storm Drain

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Microbial source tracking markers for detection of fecal contamination in environmental waters: relationships between pathogens and human health outcomes

FEMS Microbiology Reviews ◽

10.1111/1574-6976.12031 ◽

2014 ◽

Vol 38 (1) ◽

pp. 1-40 ◽

Cited By ~ 303

Author(s):

Valerie J. Harwood ◽

Christopher Staley ◽

Brian D. Badgley ◽

Kim Borges ◽

Asja Korajkic

Keyword(s):

Health Outcomes ◽

Human Health ◽

Fecal Contamination ◽

Microbial Source Tracking ◽

Source Tracking ◽

Environmental Waters

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Multi-Year Microbial Source Tracking Study Characterizing Fecal Contamination in an Urban Watershed

Water Environment Research ◽

10.2175/106143016x14798353399412 ◽

2017 ◽

Vol 89 (2) ◽

pp. 127-143 ◽

Cited By ~ 5

Author(s):

Rebecca N. Bushon ◽

Amie M.G. Brady ◽

Eric D. Christensen ◽

Erin A. Stelzer

Keyword(s):

Fecal Contamination ◽

Microbial Source Tracking ◽

Source Tracking ◽

Urban Watershed

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Evaluation of Two Library-Independent Microbial Source Tracking Methods To Identify Sources of Fecal Contamination in French Estuaries

Applied and Environmental Microbiology ◽

10.1128/aem.03003-06 ◽

2007 ◽

Vol 73 (15) ◽

pp. 4857-4866 ◽

Cited By ~ 99

Author(s):

Michèle Gourmelon ◽

Marie Paule Caprais ◽

Raphaël Ségura ◽

Cécile Le Mennec ◽

Solen Lozach ◽

...

Keyword(s):

Water Samples ◽

Fecal Contamination ◽

Microbial Source Tracking ◽

Source Tracking ◽

Rrna Gene ◽

Specific Marker ◽

Gene Markers ◽

High Level ◽

Bird Feces

ABSTRACT In order to identify the origin of the fecal contamination observed in French estuaries, two library-independent microbial source tracking (MST) methods were selected: (i) Bacteroidales host-specific 16S rRNA gene markers and (ii) F-specific RNA bacteriophage genotyping. The specificity of the Bacteroidales markers was evaluated on human and animal (bovine, pig, sheep, and bird) feces. Two human-specific markers (HF183 and HF134), one ruminant-specific marker (CF193′), and one pig-specific marker (PF163) showed a high level of specificity (>90%). However, the data suggest that the proposed ruminant-specific CF128 marker would be better described as an animal marker, as it was observed in all bovine and sheep feces and 96% of pig feces. F RNA bacteriophages were detected in only 21% of individual fecal samples tested, in 60% of pig slurries, but in all sewage samples. Most detected F RNA bacteriophages were from genotypes II and III in sewage samples and from genotypes I and IV in bovine, pig, and bird feces and from pig slurries. Both MST methods were applied to 28 water samples collected from three watersheds at different times. Classification of water samples as subject to human, animal, or mixed fecal contamination was more frequent when using Bacteroidales markers (82.1% of water samples) than by bacteriophage genotyping (50%). The ability to classify a water sample increased with increasing Escherichia coli or enterococcus concentration. For the samples that could be classified by bacteriophage genotyping, 78% agreed with the classification obtained from Bacteroidales markers.

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Microbial Source-Tracking Reveals Origins of Fecal Contamination in a Recovering Watershed

Water ◽

10.3390/w11102162 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2162 ◽

Cited By ~ 3

Author(s):

Hyatt Green ◽

Daniel Weller ◽

Stephanie Johnson ◽

Edward Michalenko

Keyword(s):

Urban Areas ◽

Bacterial Contamination ◽

Fecal Contamination ◽

Microbial Source Tracking ◽

Mitigation Strategies ◽

Source Tracking ◽

Chemical Parameters ◽

Fecal Indicator ◽

Combined Sewer ◽

Rain Events

Fecal contamination of waterbodies due to poorly managed human and animal waste is a pervasive problem that can be particularly costly to address, especially if mitigation strategies are ineffective at sufficiently reducing the level of contamination. Identifying the most worrisome sources of contamination is particularly difficult in periurban streams with multiple land uses and requires the distinction of municipal, agricultural, domestic pet, and natural (i.e., wildlife) wastes. Microbial source-tracking (MST) methods that target host-specific members of the bacterial order Bacteroidales and others have been used worldwide to identify the origins of fecal contamination. We conducted a dry-weather study of Onondaga Creek, NY, where reducing fecal contamination has been approached mainly by mitigating combined sewer overflow events (CSOs). Over three sampling dates, we measured in-stream concentrations of fecal indicator bacteria; MST markers targeting human, ruminant, and canine sources; and various physical–chemical parameters to identify contaminants not attributable to CSOs or stormwater runoff. We observed that despite significant ruminant inputs upstream, these contaminants eventually decayed and/or were diluted out and that high levels of urban bacterial contamination are most likely due to failing infrastructure and/or illicit discharges independent of rain events. Similar dynamics may control other streams that transition from agricultural to urban areas with failing infrastructure.

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Use of Bacteroidales Microbial Source Tracking To Monitor Fecal Contamination in Fresh Produce Production

Applied and Environmental Microbiology ◽

10.1128/aem.02891-13 ◽

2013 ◽

Vol 80 (2) ◽

pp. 612-617 ◽

Cited By ~ 14

Author(s):

Kruti Ravaliya ◽

Jennifer Gentry-Shields ◽

Santos Garcia ◽

Norma Heredia ◽

Anna Fabiszewski de Aceituno ◽

...

Keyword(s):

Fresh Produce ◽

Fecal Contamination ◽

Microbial Source Tracking ◽

Source Tracking ◽

Rrna Gene ◽

Specific Marker ◽

Production Environment ◽

Content Type ◽

Food Borne

ABSTRACTIn recent decades, fresh and minimally processed produce items have been associated with an increasing proportion of food-borne illnesses. Most pathogens associated with fresh produce are enteric (fecal) in origin, and contamination can occur anywhere along the farm-to-fork chain. Microbial source tracking (MST) is a tool developed in the environmental microbiology field to identify and quantify the dominant source(s) of fecal contamination. This study investigated the utility of an MST method based onBacteroidales16S rRNA gene sequences as a means of identifying potential fecal contamination, and its source, in the fresh produce production environment. The method was applied to rinses of fresh produce, source and irrigation waters, and harvester hand rinses collected over the course of 1 year from nine farms (growing tomatoes, jalapeño peppers, and cantaloupe) in Northern Mexico. Of 174 samples, 39% were positive for a universalBacteroidalesmarker (AllBac), including 66% of samples from cantaloupe farms (3.6 log10genome equivalence copies [GEC]/100 ml), 31% of samples from tomato farms (1.7 log10GEC/100 ml), and 18% of samples from jalapeño farms (1.5 log10GEC/100 ml). Of 68 AllBac-positive samples, 46% were positive for one of three human-specific markers, and none were positive for a bovine-specific marker. There was no statistically significant correlation betweenBacteroidalesand genericEscherichia coliacross all samples. This study provides evidence thatBacteroidalesmarkers may serve as alternative indicators for fecal contamination in fresh produce production, allowing for determination of both general contamination and that derived from the human host.

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