Globally, it is estimated that two billion people are using faecal-contaminated water, most of which are from developing countries (WHO/UNICEF Joint Monitoring Programme & for Water Supply, 2020). The most frightening issue is that people consume this contaminated water, which contains Escherichia coli (E. coli) (Nowicki et al., 2021; Rahman et al., 2021). The World Health Organization (WHO) report in 2019, recognized E. coli as one of the bacteria that cause most diarrheal disease outbreaks, especially in areas with inadequate sanitation and safe water for domestic use. It has been reported that diarrheal disease is responsible for 370,000 children's annual mortality worldwide(Pokharel et al., 2023). In addition, E. coli causes peritonitis, pneumonia, urinary tract infections (UTIs), and urinary bacteremia (Fan et al., 2023; Sinnott-Stutzman & Sykes, 2021). Despite E. coli being the cause of those diseases, a recent emerging concern globally is antimicrobial resistance, which is among the top ten public health threats resulting from antibiotic overuse for human treatments, in animals, food production, and disposal to the environment (Kusi et al., 2022; Salam et al., 2023).
Antimicrobial resistance develops when bacteria, viruses, fungi, and parasites evolve and no longer respond to antimicrobial agents, making infections more difficult to treat and raising the risk of disease spread, severe illness, and death (Tang et al., 2023). Notably, antibiotic resistance occurs through three primary mechanisms: i) antibiotic drug degradation by enzymes, ii) change of bacterial proteins targeted by antibiotics, and iii) alteration of the membrane permeability to antibiotics (Darby et al., 2023). In addition, extended-spectrum beta-lactamase (ESBL), a plasmid-mediated lactamase capable of hydrolyzing and deactivating beta-lactams like cephalosporin and monobactams, is a method by which E. coli gain resistance to beta-lactam antibiotics (Sawa et al., 2020). Although all enzymatic effects to maximize the ease of binding to their target sites can inactivate antibiotics, E. coli uses outlet pumps or alters membrane permeability to bring the most valuable amount of drug closer to the cell (Arbab et al., 2022).
Furthermore, it is estimated that, by the year 2050, antimicrobial-resistant pathogens are predicted to kill 4.2 million people annually in Africa, with most of those deaths expected to occur in Sub-Saharan Africa (SSA) if the current trend holds (Gwenzi et al., 2022; Sulis et al., 2022). A global scoping review (Chique et al., 2021) and other studies undertaken have related the risks of antimicrobial resistance with water sources and reported an increase in E. coli resistance to antibiotics in water sources from different countries in Africa (Babatunde et al., 2022; Ramatla et al., 2023). E coli has been reported as the leading cause of death due to antimicrobial resistance followed by Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa(Murray et al., 2022). This highlights the need to investigate antibiotic resistance in Tanzania to understand the extent of possible contaminated water sources and identify human infection hotspots. This will assist in planning control mechanisms and help prevent the spread of resistant bacterial infections in Tanzania, particular Bagamoyo district located in the coastal region, which it depends on groundwater sources as an alternative source due to an unreliable piped water supply as it has been demonstrated by (Ligate et al., 2021).
Despite the fact that Bagamoyo district relies on ground water sources as an alternate supply, various studies reveal that these water sources are influenced by physiological features, hydrology, and soil texture.(Zhang et al., 2022). This contributes to the microbial contamination of groundwater sources from sanitation facilities and favours the spread of E. coli to a larger population through the consumption of these groundwater as reported elsewhere (Indrastuti et al., 2021; Ngasala et al., 2019). Furthermore, in a simulation study examining the use of alternative unimproved water sources by (Daly & Harris, 2022), they discovered a 95% increase in annual exposure to E. coli, which WHO has identified as a highly significant and representative indicator of its greatness, leading to the worldwide antimicrobial resistance problem (Loayza et al., 2020). Due to rising concern about the prevalence of antibiotic resistance in drinking water sources in low-income countries (Ahmed et al., 2022), it is critical to investigate the exposure of groundwater sources to antibiotic-resistant E. coli. Because antibiotic-resistant genes can be vertically transported and horizontally propagated among bacteria through mobile genomic elements (Von Wintersdorff et al., 2016), this highlights the importance of monitoring and understanding the spread of antibiotic resistance to effectively combat its potential impact on public health. Therefore, this study aims to determine the prevalence of resistant E. coli and the sanitary contamination risk level of groundwater sources from sanitary facilities.