Abstract
Members of the Chlamydiales order are obligate intracellular pathogens causing acute and chronic infectious diseases. Chlamydiaceae are established agents of community- and zoonotically acquired respiratory tract infections, and emerging pathogens among the Chlamydia-related bacteria have been implicated in airway infections. The role of both in airway infections in Africa is underexplored. We performed a case -control study on the prevalence of Chlamydiaceae and Chlamydia-related emerging pathogens in children with febrile respiratory tract infections in West Africa, Ghana. Using a pan-Chlamydiales broad-range real-time PCR, we detected chlamydial DNA in 11 (1.9%) of 572 hospitalized febrile children with respiratory tract symptoms and in 24 (4.3%) of 560 asymptomatic age-matched controls (p 0.03). Chlamydiaceae were found to be common among both symptomatic and healthy Ghanaian children, with Chlamydia pneumoniae being the most prevalent species. Parachlamydiaceae were detected in two children without symptoms but not in the symptomatic group. We identified neither Chlamydia psittaci nor Simkania negevensis but a member of a new chlamydial family that shared 90.2% sequence identity with the 16S rRNA gene of the zoonotic pathogen Chlamydia pecorum. In addition, we found a new Chlamydia-related species that belonged to a novel family sharing 91.3% 16S rRNA sequence identity with Candidatus Syngnamydia venezia. The prevalence and spectrum of chlamydial species differed from previous results obtained from children of other geographic regions and our study indicates that both, Chlamydiaceae and Chlamydia-related bacteria, are not clearly linked to clinical symptoms in Ghanaian children.