Microbiological and clinical features of Corynebacterium urealyticum: urinary tract stones and genomics as the Rosetta Stone

Abstract

Corynebacterium urealyticum, formerly known as coryneform CDC group D2, was first recognized to be involved in human infections 30 years ago. It is a slow-growing, lipophilic, asaccharolytic and usually multidrug-resistant organism with potent urease activity. Its cell wall peptidoglycan, menaquinone, mycolic and cellular fatty acid composition is consistent with that of the genus Corynebacterium. DNA-DNA hybridization studies and 16S rDNA sequencing analysis have been used to determine the degree of relatedness of C. urealyticum to other corynebacterial species. The genome of the type strain consists of a circular chromosome with a size of 2 369 219 bp and a mean G + C content of 64.2%, and analysis of its genome explains the bacterium's lifestyle. C. urealyticum is a common skin colonizer of hospitalized elderly individuals who are receiving broad-spectrum antibiotics. It is an opportunistic pathogen causing mainly acute cystitis, pyelonephritis, encrusted cystitis, and encrusted pyelitis. More infrequently, it causes other infections, but mainly in patients with urological diseases. Infections are more common in males than in females, and treatment requires administration of antibiotics active against the organism in vitro, mainly glycopeptides, as well as surgical intervention, the latter mostly in cases of chronic infection. Mortality directly associated with infection by this organism is not frequent, but encrusted pyelitis in kidney-recipient patients may cause graft loss. The outcome of infection by this organism is reasonably good if the microbiological diagnosis is made and patients are treated appropriately.

The Family Corynebacteriaceae

“…Once the bacterium adheres to the epithelium of the urinary tract, it can grow under the stimulation of the urea present in the urine. The enzymatic activity of urease leads to hyperammoniuria and alkalinization of the urine which in turn causes hypersaturation with struvite and calcium phosphate with the consequent crystallization of struvite and apatite (Soriano and Tauch 2008). Both types of urinary stone have been reproduced by in vitro and in vivo experiments (Soriano et al 1986(Soriano et al , 1987.…”

“…The bacterium is a common skin colonizer of hospitalized individuals who are receiving broad-spectrum antibiotics and also an opportunistic pathogen causing acute cystitis, pyelonephritis, encrusted cystitis, and encrusted pyelitis (Soriano and Tauch 2008;Famularo et al 2008). Corynebacterium urealyticum is frequently isolated from the groin of elderly inpatients (Soriano et al 1988) which favors the colonization of urinary catheters.…”

“…Fastidious Corynebacterium species can be missed by routine culturing, because the organism does not grow after standard overnight incubation. Therefore, incubation may last longer than 24 h, at least in the case of Corynebacterium urealyticum (Soriano and Tauch 2008). A selective medium for the isolation of Corynebacterium urealyticum from urine and skin samples of hospitalized patients has been described (Zapardiel et al 1998).…”

“…Corynebacterium urealyticum is a multidrug-resistant organism with a potent urease activity (Pitcher et al 1992;Soriano and Tauch 2008) which is the major virulence factor of this pathogen. The bacterium is a common skin colonizer of hospitalized individuals who are receiving broad-spectrum antibiotics and also an opportunistic pathogen causing acute cystitis, pyelonephritis, encrusted cystitis, and encrusted pyelitis (Soriano and Tauch 2008;Famularo et al 2008).…”

Corynebacterium striatum infecting a malignant cutaneous lesion: the emergence of an opportunistic pathogen

“…However, owing to the increasing number of immunocompromised patients, some corynebacteria species have turned clinically relevant 9 . Notably, C. amycolatum, C. jeikeium and C. urealyticum are currently recognized as important pathogens 3,5,6,[8][9][10][11] . Although some reports previously described C. striatum as a causative agent of infections specially in immunocompromised patients, its role as a human pathogen is poorly understood 5,9,11 .…”