Actinobaculum schaalii in urological patients, screened with real-time polymerase chain reaction

Actinobaculum schaalii can cause urinary tract infections (UTIs) and occasionally septic complications. It is a carbon dioxide-requiring Gram-positive rod which is overlooked if urine is cultured in ambient air or if there is growth of conventional species. This study aimed to find the frequency of A. schaalii in consecutive cohorts of patients with kidney stones, children with suspected UTI and patients with indwelling catheters.

A quantitative real-time polymerase chain reaction (PCR) assay was used to screen consecutive urine samples from of 76 patients with kidney stones, 29 children and 37 with different indwelling catheters.

In patients with kidney stones, A. schaalii was found in seven (29%) of the 24 leucocyte esterase stix-positive urines, which was twice as often as in the stix-negative urines (p = 0.22), and in five (36%) of 14 children less than 3 years old but not in 15 children 3?15 years old (p = 0.02). The eight catheterized patients with A. schaalii (22%) were elderly and half had comorbidities. In the patients where A. schaalii was found, other uropathogens were found from five of the 15 patients with kidney stones, one of the five children and seven of the eight with an indwelling catheter.

Actinobaculum schaalii is common among elderly people with suspected UTI and may be clinically significant, when found alone or together with other bacteria, among children and patients treated for kidney stones.