First Detection of Mycobacterium sp. in Wastewater in Abidjan (Yopougon) Cote d’Ivoire

Non-tuberculous mycobacteria (NTM) are ubiquitous in the environment and worldwide, under certain environmental conditions, they could be responsible for skin diseases or pulmonary lesions. In Ivory Coast, Buruli ulcers endemic country, very little information concerning the epidemiology of NTM in Cote d'Ivoire is known, this ignorance has led to an underestimation of its prevalence in the environment.

Aims: The objective of this study was to characterize strains of environmental mycobacteria in wastewater located in urban areas in Abidjan (Yopougon) Côte d'Ivoire.

Place and Duration of Study: The study was conducted at Yopougon (Selmer). This site is considered to be Buruli ulcer non-endemic zone according to the national program on fight against Buruli ulcer in Côte d’Ivoire. However, all biological aspect of this work was carried out at the Pastor Institute of Côte d’Ivoire.

Methodology: Wastewater samples were collected at the surfaces at Yopougon using the technique described by Britton and Gresson. In the laboratory, these collected samples were treated according to the method described by Stinear et al. and Kankya et al. consisting of decontamination, neutralization followed by culture.

Classification of species was done according to the method described by Runyon and collaborators. Biochemical identification of mycobacteria was done according to the method described by Metchock.

Results: A total of 32 samples were collected, 8 water samples at each sampling site. After decontamination and culture, specimens grew on Lowenstein-Jensen medium after 7 days (at 37°C and 32°C) and revealed small, smooth, nonpigmented colonies. Smears confirmed the presence of variably acid-fast organisms. Biochemical traits of the isolates revealed, colony grown on Middlebrook agar 7H11 (at 37°C and 32°C); catalase (+); agar (+) (at 37°C and 32°C ); citrate (-); mannitol (-).

Conclusion: This work is one of the first study focusing on Mycobacteria in wastewater in Abidjan. The isolation of Mycobacterium sp., an environmental pathogenic organism, supports the hypothesis of possible colonization of urban wastewater by pathogenic mycobacteria. Further studies are needed to verify the involvement of this specie in mycobacterial infections in Côte d'Ivoire.