**Abstract**

This synthesis of research work considers the dynamic, antibiotic resistance, hemolytic, and hemagglutination activities of non-O1 *Vibrio cholerae* in comparison with those of fecal coliforms, fecal streptococci, and *Pseudomonas aeruginosa* isolated from suburban and rural groundwater supplies in a Marrakesh area (Morocco). In addition, it assesses the influence of some chemical factors on the distribution of all these bacterial groups. The obtained results showed that the prospected well waters contain them at varying abundance degrees while undergoing generally spatial and temporal fluctuations. The total occurrence of these bacteria during the period of study was 94%. Detectable non-O1 *V. cholerae* was present in 81% of the samples and the mean abundances ranged from 0 to 11100 MPN/100 ml. According to WHO standards for drinking water, they were heavily contaminated and could have significant health risks for the local population consuming them. Non-O1 *V. cholerae* and the other studied bacteria are virulent since most of them were found to be adhesive, producers of hemolysins and multi-resistant to antibiotics. Pollution activities around the wells lead to an increase of virulence and antimicrobial resistance in groundwater. This shows the role of these bacteria in several cases of gastro-enteric and systemic pathologies noted in Marrakech local population.

**Keywords:** non-O1 *Vibrio cholerae*, antibiotic resistance, groundwater, hemagglutination, hemolysin, chemical factors

## **1. Introduction**

Currently, pollution, water scarcity and seasonal droughts are emerging as major development challenges for many developing countries. According to data for the world's most water-stressed countries [1], Morocco is among the most vulnerable and will become a water-stressed country by 2040 [2, 3]. Thus, the preservation and management of its aquifers against various forms of pollution is a major national and regional concern. In Marrakesh area, groundwater supplies are a valuable resource for wide suburban and rural populations. However, their consumers' growth and anthropogenic activities heavily influence these wells water. In fact, due to the lack of sewerage networks and the absence of household waste collection, these people are directly discharging wastewater and solid waste onto the ground. Then, the chemical and microbial quality of well water under such environments is seriously threatened. Also, these communities rely only on these untreated wells' water as a source of human and animal drinking, domestic activities, and cultural irrigation. The use of these well waters without any previous treatment involves serious health problems due to the potential presence of pollutants and pathogenic bacteria. Water pollution has a direct impact on human health so that about 884 million people are living without access to clean drinking water in 2019 [4, 5]. According to WHO, about 1.8 million people die every year because of cholera and diarrhea, and 3900 children die every day as a result of contaminated water consumption and sanitation conditions inadequacy [6, 7]. Indeed, emergences of some aquatic diseases and sporadic outbreaks of acute diarrhea were reported on several occasions in Marrakesh area especially in the hot period [8, 9]. Even so, etiological information related to such outbreaks in this region is very limited. The occurrence of antibiotic-resistant bacteria in these wells' water could worsen more than in this previous situation. Many research studies have noted the important public health implications of the presence of antibiotic-resistant bacteria and especially multiple antibiotic-resistant bacteria, in suburban and rural groundwater [10, 11]. The horizontal gene transfer and clonal spread of resistant bacteria can mediate the transfer of not only antibiotic resistance genes but also virulence factors [12, 13].

There is a growing trend toward infection due to *Vibrio* spp., their capacity to persist in the aquatic environment and their association with abiotic and biotic factors [14, 15]. Non-O1 *Vibrio cholerae* is ubiquitously distributed in diverse aquatic environments where water acts as a reservoir and source of its transmission [16]. They are an essential and potentially life-threatening cause of infections that are primarily related to the consumption of feces-contaminated water and person-to-person transmission [17–19]. This pathogen leads to self-limiting gastroenteritis, septicemia, bacteremia, meningoencephalitis, oral infection, wound or ear infections, and non-epidemic diarrhea with a fatal outcome in immunocompromised hosts with predisposing medical conditions [19–23]. Different virulence factors have been suggested to be involved in these diseases such as a heat-stable toxin, hemolysin and other cell-associated hemagglutinins [24–26]. Few studies have been conducted in Morocco on the occurrence of antibiotic resistance and virulence factors of non-O1 *V. cholerae* in groundwater supplies in Morocco and particularly in the Marrakesh area. Accordingly, this study presents a synthesis of our research works on the dynamics, occurrence of antibiotic resistance, and potential virulence of non-O1 *V. cholerae* in supplying well water in comparison with other bacteria. The incidence of hemolytic and hemagglutination activities and the importance of some chemical parameters on the distribution of non-O1 *V. cholerae*, *Pseudomonas aeruginosa*, fecal coliforms (FC), and fecal streptococci (FS) is discussed.
