Among water treatment techniques, UV rays are mainly used to disinfect packaged drinking water. The
objective of this study was to evaluate the effectiveness of water disinfection by UV rays in packaged water
production companies in the city of Ouagadougou. Fifty-four (54) packaged water samples were taken from 27
companies in the city of Ouagadougou. Detection of different microorganisms was carried out using the
membrane filtration method. The identification of the isolated coliforms was made using the API 20E trips.
Antibiotic resistance was assessed using the KIRBY BAUER agar diffusion method. using ampicillin,
amoxiclllin, cetazidim, ceftriazone, imipenem, meropenem, kanamycin, gentamicin, ciprofloxacin and
norfloxacin. The results of microbiological investigations showed the presence of bacteria in some packaged
water from certain companies. Of the 27 companies investigated, total coliforms were detected in 20 companies,
E. coli in one company, Pseudomonas aeruginosa in one company, and sulfite-reducing anaerobic bacteria in 4
companies. Of the 27 companies, the effectiveness of UV disinfection was observed in only 25.92% with a total
absence of coliforms, E. coli, intestinal enterococci, Pseudomonas aeruginosa and sulphite-reducing anaerobic
bacteria. Twelve (12) species of coliforms including Enterobacter ssp, Enterobacter cloacae, Enterobacter
amnigenus, Serratia liquefaciens, Chryseomonas luteola, Chryseobacterium indologenes, Stenotrophomonas
maltophilia, Myroides spp, Pantoea spp, Burkholderia cepacia, Serratia ficaria and Enterobacter sakazakii
have been detected. The resistance profile showed that some coliforms were resistant to β-lactams and
aminoglycosides. This study shows that the technique of disinfection of water by UV rays is not effective in
certain companies in Ouagadougou and could be explained by diverse reasons including UV systems defiances.

Packaged water, disinfection, ultraviolet, antibiotic resistance