# Molecular surveillance of Helicobacter species with high prevalence from two streams with various wastewater pollution in Taiwan

## TL;DR

This study analyzed Helicobacter species in two rivers in Taiwan and found high prevalence, especially in areas with livestock, suggesting wastewater pollution as a source.

## Contribution

The study identifies Helicobacter kayseriensis as the most common species in polluted streams and links its presence to livestock and pH levels.

## Key findings

- Helicobacter species were detected in 79.55% of water samples from the rivers.
- H. kayseriensis was the most prevalent species, particularly in livestock-rich areas.
- A significant difference in Helicobacter presence was found based on pH levels.

## Abstract

Helicobacter species are potential zoonotic pathogens classified as either enterohepatic or gastric. Helicobacter infection can be transmitted through wastewater from households and livestock and through water from irrigation and streams. In this study, the distribution and source of Helicobacter species in the Donggang and Yenshui rivers, two natural water bodies with different characteristics, were analyzed. A total of 44 water samples were collected over the four seasons. The samples were subjected to Helicobacter 16 s rRNA gene PCR, followed by sequencing and comparison for identification and analysis. The detection rate of Helicobacter species in both rivers was 79.55%, with H. kayseriensis (10/35, 28.57%) being the most common species. Analysis of the environment around the sampling sites showed a high detection rate in the livestock-rich area, and the results of BLAST for species identification and comparison indicated feces as the contamination source. The area around the Donggang River was developed for animal husbandry, led to a high detection rate of Helicobacter species. Many Helicobacter species were identified to have a risk of zoonotic transmission, especially if the stream is used as a source of drinking, agricultural, or even aquacultural water. The high presence of Helicobacter species in natural water bodies suggests that wastewater treatment is an effective strategy to control pathogen spread. Therefore, investigation and monitoring of pathogens in wastewater are highly important. However, methods for the isolation and culture of Helicobacter species in natural waters have yet to be developed. Hence, future research should focus on developing such methods.

•Only amplicon TKC5-Sp belonged to the gastric Helicobacter group.•Helicobacter kayseriensis was the most prevalent species in the two streams.•Helicobacter species were detected in the Donggang River, a drinking water source.•Significant difference was found between pH and Helicobacter presence.

Only amplicon TKC5-Sp belonged to the gastric Helicobacter group.

Helicobacter kayseriensis was the most prevalent species in the two streams.

Helicobacter species were detected in the Donggang River, a drinking water source.

Significant difference was found between pH and Helicobacter presence.