Date of Award
Summer 6-10-2026
Document Type
Thesis
Degree Name
Master of Biological Science (MBioSci)
Department
Biological & Agricultural Engineering
First Advisor
Dave Bachoon
Second Advisor
Alfred Mead
Third Advisor
Christopher Burt
Abstract
Helicobacter pylori is a fecally shed, Gram negative human pathogen that can enter wastewater and surface water systems and is a major etiologic agent of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa associated lymphoid tissue lymphoma. Because infected individuals may release the organism or its DNA through feces, inadequate sanitation, wastewater discharges, septic leakage, and contaminated runoff can introduce H. pylori into aquatic environments. This creates a potential pathway for exposure through recreational water, drinking water sources, irrigation, or contaminated foods.
Helicobacter pylori DNA was detected in 45 of 190 samples (23.7%), including 21 of 82 samples in 2024 (25.6%) and 24 of 108 samples in 2025 (22.2%). Detection did not differ significantly between years (p = 0.609), between the two 2024 periods (p = 1.000), between the two 2025 periods (p = 0.643), or between pooled early- and later year periods (p = 0.864). Human associated fecal contamination was significantly more frequent in SJBE than RGDL in both 2024 and 2025 (both p < 0.001), and dog associated contamination was significantly more frequent in SJBE in 2025 (p < 0.001). Horse- and rat associated fecal contamination did not differ significantly between estuaries. H. pylori detection also did not differ significantly between SJBE and RGDL in 2024 (p = 0.139) or 2025 (p = 0.450). In the pooled dataset, no fecal source marker was significantly associated with H. pylori detection: human (p = 0.169), dog (p = 0.661), horse (p = 0.300), and rat (p = 0.367). The only significant period specific relationship occurred in March 2025, when rat positive samples had 5.32 times higher odds of H. pylori detection (φ = 0.333, p = 0.027). These findings demonstrate that H. pylori was repeatedly detected in Puerto Rican estuarine waters but was not consistently linked to one host associated fecal source. Its occurrence may reflect multiple contamination pathways, intermittent shedding, hydrologic mixing, and environmental persistence.
Recommended Citation
Sarran*, Alex A.F., "Evaluating the Potential Sources of Helicobacter pylori in San Juan Bay and Río Grande de Loíza Estuaries of Puerto Rico" (2026). Biology Theses. 53.
https://kb.gcsu.edu/biology/53