The Fascinating Cross-Paths of Pathogenic Bacteria, Human and Animal Faecal Sources in Water-Stressed Communities of Vhembe District, South Africa

Abstract

Access to clean and safe drinking water still remains a major challenge in the developing world, causing public health risks in terms of waterborne infections, especially in rural areas of sub-Saharan Africa. This study aimed to track and detect enteric pathogens (Salmonella enterica subsp. enterica serovar Typhimurium str. LT2, Shigella flexneri, and Campylobacter jejuni subsp. jejuni) in rural water sources. It also sought to establish a correlation between these pathogens and the sources of faecal pollution. Multiplex qPCR and specific primers and probes were used for detection and tracking. The study successfully correlated the occurrence of target pathogens with sources of human and animal faecal contamination using host-specific genetic markers (BacHum and HF183 for humans, BacCow for cows, Pig-2-Bac for pigs, Cytb for chickens, and BacCan for dogs). The study revealed that enteric pathogens were found in 47.69% and 32.80% of samples during the wet and dry seasons, respectively. These pathogens were associated with human or animal faecal contamination. Correlations between pathogens and contamination sources were significant (p ≤ 0.05), with varying strengths during the wet and dry seasons. The findings emphasize the importance of identifying faecal contamination sources to protect rural communities from waterborne infections.

Keywords: enteric pathogens; faecal pollution; multiplex real-time PCR; rural areas; water-stressed areas.

Figure 1

Map showing sampled villages, water treatment plants, and rivers.

Figure 2

Standard curves for enteric pathogens.

Figure 3

The prevalence of Campylobacter jejuni subsp. jejuni, Shigella flexneri, and Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 during wet and dry seasons.

Figure 4

The prevalence of Campylobacter jejuni subsp. jejuni, Shigella flexneri, and Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources used in selected villages.

Figure 5

(A): Number of markers associated with the presence of Campylobacter jejuni subsp. jejuni in water sources during the rainy season. E1: HHS (Lambani household storage); B28: XRAW (Xikundu Water Treatment Works raw water, Xikundu); B30: ALD (Luvuvhu River downstream of Xikundu Water Treatment Works); B31: ALU (Luvuvhu River upstream of Xikundu Water Treatment Works). (B): Number of markers associated with the presence of Campylobacter jejuni subsp. jejuni in the water sources during the dry season. E23: XRAW (Xikundu Water Treatment Works raw water, Lambani samples); K40: KLD (Luvuvhu River downstream, Gandlanani Village); K41: KLU (Luvuvhu River upstream, Gandlanani Village). (C): Number of markers associated with the presence of Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources during the rainy season. E2–E17: Lambani HHS; I1–I19: Tshifudi HHS; I22: XRAW: Xikundu Water Treatment Works raw water; K1–K34: Gandlanani HHS; K40–K42: Gandlanani Luvuvhu River; B5–B15: Makuleke HSS; B28: XRAW, B31: Xikundu Luvuvhu River; N5–N17: Njhakanjhaka stored borehole water. (D): Number of markers associated with the presence of Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources during the dry season. E6–E17: Lambani HHS; E23: XRAW: Xikundu Water Treatment Works raw water; I9–I19: Tshifudi HHS, I22: XRAW; K1–K32: Gandlanani HHS; K40–K42: Gandlanani Luvuvhu River; B3–B25: Makuleke HSS, B29: XRAW; B31: Xikundu Luvuvhu River; N8: Njhakanjhaka stored borehole water. (E): Number of markers associated with the presence of Shigella flexneri in water sources during the rainy season. E2–E10: Lambani HHS; * E24: XFINAL (Xikundu Water Treatment Works final water); I3–I21: Tshifudi HHS; I24: Xikundu Luvuvhu River Extraction point; K8–K33: Gandlanani HHS; * K40: Gandlanani Luvuvhu River; B1–B26: Makuleke HSS; B30: ALD Xikundu Luvuvhu River downstream; N1–N8: Njhakanjhaka stored borehole water. (F): Number of markers associated with the presence of Shigella flexneri in possible water sources during the dry season. E10–E19: Lambani HHS; E22: Xikundu Luvuvhu River Extraction; E23: XRAW (Xikundu Water Treatment Works Raw water); I4–I20: Tshifudi HHS; I24: Xikundu Luvuvhu River; K1–K34: Gandlanani HHS; K40: Gandlanani Luvuvhu River; B18: Makuleke HSS; B30: ALD (Xikundu Luvuvhu River downstream, Makuleke Village), B31: ALU (Xikundu Luvuvhu River upstream, Makuleke village); N1–N10: Njhakanjhaka stored borehole water.

Figure 5

(A): Number of markers associated with the presence of Campylobacter jejuni subsp. jejuni in water sources during the rainy season. E1: HHS (Lambani household storage); B28: XRAW (Xikundu Water Treatment Works raw water, Xikundu); B30: ALD (Luvuvhu River downstream of Xikundu Water Treatment Works); B31: ALU (Luvuvhu River upstream of Xikundu Water Treatment Works). (B): Number of markers associated with the presence of Campylobacter jejuni subsp. jejuni in the water sources during the dry season. E23: XRAW (Xikundu Water Treatment Works raw water, Lambani samples); K40: KLD (Luvuvhu River downstream, Gandlanani Village); K41: KLU (Luvuvhu River upstream, Gandlanani Village). (C): Number of markers associated with the presence of Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources during the rainy season. E2–E17: Lambani HHS; I1–I19: Tshifudi HHS; I22: XRAW: Xikundu Water Treatment Works raw water; K1–K34: Gandlanani HHS; K40–K42: Gandlanani Luvuvhu River; B5–B15: Makuleke HSS; B28: XRAW, B31: Xikundu Luvuvhu River; N5–N17: Njhakanjhaka stored borehole water. (D): Number of markers associated with the presence of Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources during the dry season. E6–E17: Lambani HHS; E23: XRAW: Xikundu Water Treatment Works raw water; I9–I19: Tshifudi HHS, I22: XRAW; K1–K32: Gandlanani HHS; K40–K42: Gandlanani Luvuvhu River; B3–B25: Makuleke HSS, B29: XRAW; B31: Xikundu Luvuvhu River; N8: Njhakanjhaka stored borehole water. (E): Number of markers associated with the presence of Shigella flexneri in water sources during the rainy season. E2–E10: Lambani HHS; * E24: XFINAL (Xikundu Water Treatment Works final water); I3–I21: Tshifudi HHS; I24: Xikundu Luvuvhu River Extraction point; K8–K33: Gandlanani HHS; * K40: Gandlanani Luvuvhu River; B1–B26: Makuleke HSS; B30: ALD Xikundu Luvuvhu River downstream; N1–N8: Njhakanjhaka stored borehole water. (F): Number of markers associated with the presence of Shigella flexneri in possible water sources during the dry season. E10–E19: Lambani HHS; E22: Xikundu Luvuvhu River Extraction; E23: XRAW (Xikundu Water Treatment Works Raw water); I4–I20: Tshifudi HHS; I24: Xikundu Luvuvhu River; K1–K34: Gandlanani HHS; K40: Gandlanani Luvuvhu River; B18: Makuleke HSS; B30: ALD (Xikundu Luvuvhu River downstream, Makuleke Village), B31: ALU (Xikundu Luvuvhu River upstream, Makuleke village); N1–N10: Njhakanjhaka stored borehole water.

Figure 5

(A): Number of markers associated with the presence of Campylobacter jejuni subsp. jejuni in water sources during the rainy season. E1: HHS (Lambani household storage); B28: XRAW (Xikundu Water Treatment Works raw water, Xikundu); B30: ALD (Luvuvhu River downstream of Xikundu Water Treatment Works); B31: ALU (Luvuvhu River upstream of Xikundu Water Treatment Works). (B): Number of markers associated with the presence of Campylobacter jejuni subsp. jejuni in the water sources during the dry season. E23: XRAW (Xikundu Water Treatment Works raw water, Lambani samples); K40: KLD (Luvuvhu River downstream, Gandlanani Village); K41: KLU (Luvuvhu River upstream, Gandlanani Village). (C): Number of markers associated with the presence of Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources during the rainy season. E2–E17: Lambani HHS; I1–I19: Tshifudi HHS; I22: XRAW: Xikundu Water Treatment Works raw water; K1–K34: Gandlanani HHS; K40–K42: Gandlanani Luvuvhu River; B5–B15: Makuleke HSS; B28: XRAW, B31: Xikundu Luvuvhu River; N5–N17: Njhakanjhaka stored borehole water. (D): Number of markers associated with the presence of Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 in water sources during the dry season. E6–E17: Lambani HHS; E23: XRAW: Xikundu Water Treatment Works raw water; I9–I19: Tshifudi HHS, I22: XRAW; K1–K32: Gandlanani HHS; K40–K42: Gandlanani Luvuvhu River; B3–B25: Makuleke HSS, B29: XRAW; B31: Xikundu Luvuvhu River; N8: Njhakanjhaka stored borehole water. (E): Number of markers associated with the presence of Shigella flexneri in water sources during the rainy season. E2–E10: Lambani HHS; * E24: XFINAL (Xikundu Water Treatment Works final water); I3–I21: Tshifudi HHS; I24: Xikundu Luvuvhu River Extraction point; K8–K33: Gandlanani HHS; * K40: Gandlanani Luvuvhu River; B1–B26: Makuleke HSS; B30: ALD Xikundu Luvuvhu River downstream; N1–N8: Njhakanjhaka stored borehole water. (F): Number of markers associated with the presence of Shigella flexneri in possible water sources during the dry season. E10–E19: Lambani HHS; E22: Xikundu Luvuvhu River Extraction; E23: XRAW (Xikundu Water Treatment Works Raw water); I4–I20: Tshifudi HHS; I24: Xikundu Luvuvhu River; K1–K34: Gandlanani HHS; K40: Gandlanani Luvuvhu River; B18: Makuleke HSS; B30: ALD (Xikundu Luvuvhu River downstream, Makuleke Village), B31: ALU (Xikundu Luvuvhu River upstream, Makuleke village); N1–N10: Njhakanjhaka stored borehole water.