**4. Discussion**

This study investigated the occurrence of potentially pathogenic strains of *E. coli* recovered from beach water samples. Among the total number of presumptive *E. coli* isolates screened, 73 (68%) were confirmed positive by molecular techniques, in accordance with the report of Whitman et al. [28]. The presence of these bacteria in beach water poses a high risk with regard to human contact with this water, and there are certain factors which may be responsible for the fewer number of confirmed pathogens. There is the tendency of a low survival rate due to the depth of the beach water and rapid movement of the sea waves, with a possibly high level of dilution involved [29]. Moreover, there appears to be a higher level of fecal contamination near the sea shore around the sampling points, due to the high turbidity [30,31]. In general, the presence of pathogenic *E. coli* obtained from all sampling points of this recreational facility can pose serious health risks to both tourists and bathers. A study by Tsai et al. [32] suggested that certain pedigrees of *E. coli* have adapted and become accustomed to the different aquatic milieu, and this corroborates with our results. It was observed that bacterial counts from the sampling points where wastewater was being discharged into the beach had the highest number of positive isolates during the spring season and festive period, and our findings support the report of de Carvalho and Neto [33]. Although there are many probable sources of contamination, sewage treatment plants (STP) have become a constant source of beach pollution in respect of the quality of the final effluents that are released into receiving waters [34].

The result from the PCR products of the 260 presumptive *E. coli* isolates screened is; 107 isolates were positive, and our result is in agreement with the report of da Costa Andrade et al. [35]. Another study by Partyka et al. [36] also identified *E. coli* from beach water, and this is also in line with our result. From the eight different *E. coli* pathotypes screened for, three groups of *E. coli* pathotypes were identified as belonging to the two categories, InPEC (EPEC and EIEC) and ExPEC (NMEC) and the frequencies of detection ranged between 10% [InPEC] and 45% [ExPEC]. The molecular identification of *E. coli* pathogens in beach water poses high risk to the people in that area who use the beach for recreational activity. This study showed that 11 (10.3%) of the 73 positive strains of *E. coli* belonged to enteropathogenic *E. coli*. A study by Byappanahalli et al. [37] has also reported the presence of EPEC strains in beach water, and this is also in line with our result. Another study by Maloo [38], carried out in India, also identified various pathotypes of *E. coli* recovered from beach water, and our report is in line with their findings. The order of the percentage of phenotypic resistance levels exhibited by the isolates against the antibiotics is as follows: ampicillin (100%), amikacin (96%), gentamycin (96%), ceftazidime (96%), tetracycline (92%), ciprofloxacin (85%), trimethoprim (84%), and norflaxacin (62%). However, the isolates were mostly susceptible to norflaxacin. A study conducted by Stoll et al. [39] in Germany and Australia revealed a high resistance rate in *E. coli* isolates recovered from surface water samples that were resistant against ampicillin and tetracycline, and our result is in accordance with their report. A high percentage of the phenotypic resistance observed in the *E. coli* isolated could either be from the origin of WWTP or agricultural waste (poultry droppings), as most of the final effluents have been discharged into water bodies [40,41].

A multiple antibiotic resistance index (MARI) was carried out in order to evaluate or assess health risks that were concomitant with the rise and spread of multidrug resistance in the environment. The MARI value of 0.2 (arbitrary) was utilized to distinguish between low and high risk to public health. In addition, a MARI value above 0.2 proposed that the pathogenic strain of bacteria originated from an environment which was highly contaminated or which had high levels of antibiotics usage [19,26]. From our study, the MARI value (0.05) obtained for the isolates was less than 0.2, signifying that the isolates originated from environments with minimal antimicrobial use. The low MARI value estimated in this study provides an opportunity for further research in this area. This could be as a result of unsuitable use of antibiotics among the populace in the study area, and any greater MARI value

obtained will suggest exposure to antimicrobial pressure, which may perhaps eventually lead to an increase in multidrug resistance.
