Potential for gulls to transport bacteria from human waste sites to beaches

Abstract

Contamination of recreational beaches due to fecal waste from gulls complicates beach monitoring and may pose a risk to public health. Gulls that feed at human waste sites may ingest human fecal microorganisms associated with that waste. If these gulls also visit beaches, they may serve as vectors, transporting fecal microorganisms to the beach where they may subsequently contaminate sand and water. In this study, samples collected from landfills, treated wastewater storage lagoons, and public beaches demonstrated a spatial and temporal overlap of markers for gull and human-associated microorganisms. In addition, markers for gull, fecal indicator bacteria, and the human-associated marker, HF183, were detected in gull feces and cloacae samples. Further, HF183 was detected in cloacae samples from gulls that were documented by radio-telemetry traveling between human waste sites and public beaches. This study highlights the potential for gulls that visit human waste sites to disperse human-associated microorganisms in the beach landscape.

Gulls as Sources of Environmental Contamination by Colistin-resistant Bacteria

“…We propose that gulls serve as useful sentinels for mcr-1 and other clinically relevant forms of colistin resistance in the environment because of the mobility of gulls, their ability to disseminate both pathogenic and antimicrobial resistant bacteria throughout agricultural landscapes 26 and environments used by people 12,27,28 , the apparent asymptotic colonization of experimentally challenged birds with E. coli harboring colistin resistance, and the evidence for extensive environmental contamination by gulls via fecal shedding. Furthermore, we propose that gulls play a role in environmental pathways through which mcr-1 positive E. coli could be disseminated to humans or domestic animals through fecal contamination of public areas by gulls, e.g.…”

“…Furthermore, we propose that gulls play a role in environmental pathways through which mcr-1 positive E. coli could be disseminated to humans or domestic animals through fecal contamination of public areas by gulls, e.g. 12 , or agricultural operations 26 (Fig. 5).…”

“…Since initial discovery in domestic animals in China, mcr-1 was found in fecal bacteria from European herring gulls (Larus argentatus) in Lithuania, kelp gulls (Larus domnincanus) in Argentina, and yellow-legged gulls (Larus michahellis) in Spain and Portugal [8][9][10] , which provides evidence that this gene may spread, in part, via environmental pathways. Gulls could play an important role in disseminating mcr-1 among poultry, livestock, humans, and environmental sources given their wide-ranging movements, use of human waste sites and livestock feed, and propensity to spread bacterial pathogens 11,12 . For example, satellite-tracked glaucous-winged gulls (Larus glaucescens) made local movements up to 80 km during the breeding season, foraged at landfills during non-breeding periods, and migrated up to 3600 km in 63-75 days 13 .…”

Highly Specific Sewage-Derived Bacteroides Quantitative PCR Assays Target Sewage-Polluted Waters

“…Cross-reaction of human fecal markers with animals can be influenced by multiple complex factors, such as similarities in gut microbial communities as a result of dietary factors (25,35,51) and possible animal ingestion of human waste (52). We have previously noted that employing markers from two different bacterial groups, such as Bacteroides and Lachnospiraceae, can increase confidence in results where crossreactivity is suspected (25).…”

Optical Parameters for Using Visible-Wavelength Reflectance or Fluorescence Imaging to Detect Bird Excrements in Produce Fields

“…The problem with birds is that they can visit a field, leave their droppings, and depart without leaving any readily identifiable indications that they have ever been in the field. Birds, and particularly gulls, are known carriers of human pathogens [8][9][10], and have been implicated in the contamination of local waters [10][11][12][13].…”