In public discharge soiled by various wastes, including the excrement of poultry, hospitals, and agri-food industries, that the commensal birds that are the subject of our studies feed. By feeding in these garbage dumps, commensal birds become infected with bacteria present in the feces, thus becoming reservoirs and/or potential vectors of various known diseases in humans. In this chapter, some Enterobacteriaceae and ectoparasites of birds that frequent humans for food and shelter will be presented because they are responsible for various diseases known in humans. This chapter is therefore part of this new “One Health” approach. It involves the identification of ectoparasites of commensal bird vectors of known diseases in humans and in livestock farming, the determination of the composition of the intestinal microbiota of some commensal birds in the city of Kinshasa, the mapping of antibiotic resistance in Enterobacteriaceae of stray chickens, and the search for new sensitive molecular derived from antibiotics commonly used in the city of Kinshasa. In addition, this chapter illustrates the ecological role of birds as biological indicators of environmental quality.