Leishmaniasis is a zoonotic and neglected disease, which represents an important public health problem worldwide. Different species of Leishmania are associated with different manifestations, and a practical problem that can worsen the condition of hosts infected with Leishmania is the secondary infection caused by bacteria. This review aims to examine the importance and prevalence of bacteria co-infection during leishmaniasis and the nature of this ecological relationship. In the cases discussed in this review, the facilitation phenomenon, defined as any interaction where the action of one organism has a beneficial effect on an organism of another species, was considered in the Leishmania-bacteria interaction, as well as the effects on one another and their consequences for the host.
Keywords: bacterial co-infection; leishmaniasis; opportunistic bacteria; secondary infection; symbiotic facilitation.