Prevalence and antimicrobial susceptibility of species in human stool samples derived from out- and inpatients: the prospective German prevalence study Arcopath.

Background: species, particularly , but also constitute emerging pathogens causing gastroenteritis in humans. However, isolation of may often fail during routine diagnostic procedures due to the lack of standard protocols. Furthermore, defined breakpoints for the interpretation of antimicrobial susceptibilities of are missing. Hence, reliable epidemiological data of human infections are scarce and lacking for Germany. We therefore performed a 13-month prospective prevalence study in German patients.

Results: A total of 4636 human stool samples was included and spp. were identified from 0.85% of specimens in 3884 outpatients and from 0.40% of specimens in 752 hospitalized patients. Overall,   was the most prevalent species (n = 24; 67%), followed by   (n = 10; 28%) and   (n = 2; 6%). Whereas    and   were identified in outpatients, only   could be isolated from samples of hospitalized patients. Antimicrobial susceptibility testing of isolates revealed high susceptibilities to ciprofloxacin, whereas bimodal distributions of MICs were observed for azithromycin and ampicillin.

Conclusions: In summary, including , and could be isolated in 0.85% of German outpatients and ciprofloxacin rather than other antibiotics might be appropriate for antibiotic treatment of infections. Further epidemiological studies are needed, however, to provide a sufficient risk assessment of infections in humans.