Prostate calcifications : answers to a clinical "enigma"

S. Mazzoli

STD's Center ASL of Florence S.M., Dept. of Sexually Transmitted Diseases, Florence, Italy

Tommaso Cai*, Francesca Meacci**, Riccardo Bartoletti***

(*) U.O. Urologia, Ospedale Santa Chiara, Trento

(**) STD's Center ASL of Florence S.M., Dept. of Sexually

Transmitted Diseases, Florence, Italy

(***) U.O. Urologia, Ospedale Santa Maria Annunziata, Università di Firenze, Firenze, Italy

Scopo del lavoro

Prostatic calcifications (PC) aetiology is unknown and their relation with genital or urinary
tract infections seem to be unclear. Prostate ducts calcifications are usually diagnosed by
Xray or suprapubic/transrectal ultrasound and easily found during transurethral resection of
prostate. They may also be detected by computed tomography or magnetic resonance and
occurs in 7-10% of patients with benign prostate hyperplasia. Patholologists support the
theory of calcified corpora amylacea (CA): these are small round or ovid bodies seen in the
lumen of the prostatic acini, which may be derived from desquamated epithelial cells and
proteinaceous material. In 2009 Sfanos K S et al. (PNAS 2009) demonstrated that acute
inflammatory proteins constitute the organic matrix of prostatic CA and calculi showing that
the most prevalent protein is lactoferrin and that several other proteins are components of
neutrophil granules. Aim of the present study was to characterize prostate calcifications by
scanning electron microscope (SEM) and perform a correlation with bacterial biofilm obtained
from patients with chronic bacterial prostatitis.

Materiali e Metodi

150 clinical bacterial strains isolated from CBP-NIH-II-patients afferent to our Centre for
Prostatitis in 2008. Bacterial strains consisted were: 50 Enterococcus faecalis; 50
Staphylococcus spp.; 30 E.coli; 20 gram- miscellanea. Their characterization and antibiotic
chemosensitivity were determined by Vitek II System (Bio-Merieux, Italy). Quantitative assay
of biofilm production and adhesion was performed according to classic Christensen et al.
micro well assay (J.Clin.Microb, 1985). Isolates were classified into “non producer, weak,
moderate and strong producer”. Simultaneously prostate calcifications were obtained from 10
patients undergone to transurethral resection for benign prostate hyperplasia. Calculi were
stained in saline solution then crushed and evaluated by both microbiological analysis and
SEM.

Risultati

The isolated bacteria were coherent with the isolation in EPS, calcification culture and SEM
microscopy in the same patient. The majority of E. coli, gram negatives, Staphylococci and
Enterococci strains were strong or medium producer: 63-30, 75-15, 46-36, 58-14 percent
respectively. Globally 84,6% of the strains produced a consistent biofilm (strong or medium
producer).

Discussione

Bacterial biofilm was obtained from prostate fluids of patients with bacterial prostatitis. This
could justify both the high rate of disease recurrences after antibiotic treatments and the
development of prostate calcifications in the same patients.

Messaggio conclusivo

Our preliminary electron microscopy study demonstrated that prostate
calcification ultrastructure is very similar to biofilm micro-structure formed "in vitro" from
bacteria obtained from chronic prostatitis patients.