Association between the presence of bacterial 16S RNA in prostate specimens taken during transurethral resection of prostate and subsequent risk of prostate cancer (Sweden).
OBJECTIVE
To study bacterial 16S RNA in archival prostate samples from 352 patients with benign prostate hyperplasia (BPH) and evaluate whether the presence of bacterial DNA was different in those who later developed prostate cancer (n = 171) and in the matched controls that did not progress to cancer (n = 181).


METHODS
16S DNA PCR followed by cloning and sequencing the positive samples.


RESULTS
In 96/352 (27%) of the prostate tissue specimens 16S RNA were detected. Sequence analysis revealed Propionibacterium acnes as the predominant microorganism (23% of 16S RNA positive patients). The second most frequent isolate-Escherichia coli was found in 12 (12%) patients. The other isolates included Pseudomonas sp. (3 patients), Actinomyces sp. (2), Streptococcus mutans (1), Corynebacterium sp. (2), Nocardioides sp. (1), Rhodococcus sp. (1) Veillonella sp. (2). In P. acnes positive samples 62% exhibited severe histological inflammation versus 50% in the bacteria-negative group (p = 0.602). The presence of P. acnes in the prostate was associated with prostate cancer development (OR 2.17, 95% CI 0.77-6.95).


CONCLUSIONS
This study has revealed P. acnes as the most common bacteria in the prostate in BPH. Further studies are needed to clarify its role in contributing to the development of prostatic inflammation and prostate cancer.
Alexeyev
O
O
Department of Medical Biosciences/Pathology, Umeå University, S-90185, Umeå, Sweden. oleg.alexeyev@medbio.umu.se
Bergh
J
J
Marklund
I
I
Thellenberg-Karlsson
C
C
Wiklund
F
F
Grönberg
H
H
Bergh
A
A
Elgh
F
F
D000368:Aged; D016022:Case-Control Studies; D004269:DNA, Bacterial / Q000302:isolation & purification; D018450:Disease Progression; D005500:Follow-Up Studies; D016905:Gram-Negative Bacterial Infections / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D016908:Gram-Positive Bacterial Infections / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D016133:Polymerase Chain Reaction; D011425:Propionibacterium acnes / Q000302:isolation & purification; D011470:Prostatic Hyperplasia / Q000382:microbiology / Q000601:surgery; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000382:microbiology* / Q000601:surgery*; D012329:RNA, Bacterial / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000302:isolation & purification; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017423:Sequence Analysis, RNA; D012720:Severity of Illness Index; D013048:Specimen Handling; D013548:Sweden / Q000453:epidemiology; D020728:Transurethral Resection of Prostate; D016896:Treatment Outcome
D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S