Chronic prostatic infection: Microbiological findings in two Mediterranean populations

INTRODUCTION/AIM

Despite accumulated knowledge, several microbiological aspects of chronic bacterial prostatitis (CBP) remain uncertain. The aim of our study was to determine microbiological characteristics on our CBP population.

MATERIALS

The material of this retrospective study consisted in bacterial isolates from urine and/or prostatic secretions or sperm cultures (total ejaculate) obtained from individuals with prostatitis symptoms and from patients with febrile relapses of CBP visiting our department, from 03/2009 to 03/2015. Retrospective data from an Italian single-center database (years 2009-2015) were also collected for a tentative comparison of pathogen prevalence between chronic bacterial prostatitis cases assessed in Greece and Italy.

RESULTS

A total of 389 bacterial isolates obtained from eligible Greek patients constituted the material of the study. While E coli was the most frequent individual pathogen, Gram-positive species were overly more frequent than Gram-negative. Besides the high frequency of E. coli and E. faecalis isolates the most remarkable similarity between Greek and Italian databases was the wide array of different Gram-positive and Gram-negative species isolated from CBP patients.

CONCLUSIONS

In Greece, the incidence of CBP is possibly higher than that reported in international surveys. Similarities between Greek and Italian databases suggest geographical trends in CBP epidemiology.

Multidisciplinary approach to prostatitis

The modern clinical research on prostatitis started with the work of Stamey and coworkers who developed the basic principles we are still using. They established the segmented culture technique for localizing the infections in the males to the urethra, the bladder, or the prostate and to differentiate the main categories of prostatitis. Such categories with slight modifications are still used according to the NIH classification: acute bacterial prostatitis, chronic bacterial prostatitis, Chronic Pelvic Pain Syndrome (CPPS) and asymptomatic prostatitis. Prostatic inflammation is considered an important factor in influencing both prostatic growth and progression of symptoms of benign prostatic hyperplasia and prostatitis. Chronic inflammation/neuroinflammation is a result of a deregulated acute phase response of the innate immune system affecting surrounding neural tissue at molecular, structural and functional levels. Clinical observations suggest that chronic inflammation correlates with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and benign prostatic hyperplasia (BPH) and an history of clinical chronic prostatitis significantly increases the odds for prostate cancer. The NIHNIDDK classification based on the use of the microbiological 4- glasses localization test or simplified 2-glasses test, is currently accepted worldwide. The UPOINT system identifies groups of clinicians with homogeneous clinical presentation and is used to recognize phenotypes to be submitted to specific treatments. The UPOINTS algorithm implemented the original UPOINT adding to the urinary domains (U), psycho-social (P), organspecific (O), infection (I), neurological (N), muscle tension and tenderness (T) a further domain related to sexuality (S). In fact sexual dysfunction (erectile, ejaculatory, libido loss) has been described in 46-92% of cases with a high impact on the quality of life of patients with CP/CPPS. Prostatic ultrasound represents the most popular imaging test in the work-up of either acute and chronic prostatitis although no specific hypo-hyperechoic pattern has been clearly associated with chronic bacterial prostatitis and CPPS. Use of a digital-processing software to calculate the extension of prostatic calcification area at ultrasound demonstrated a higher percentage of prostatic calcification in patients with chronic bacterial prostatitis. Multiparametric Magnetic Resonance Imaging (mpMRI) is the current state-of-the art imaging modality in the assessment of patients with prostate cancer although a variety of benign conditions, including inflammation, may mimic prostate cancer and act as confounding factors in the discrimination between neoplastic and non-neoplastic lesions. Bacteria can infect prostate gland by: ascending the urethra, reflux of urine into the prostatic ducts, direct inoculation of bacteria through inserted biopsy needles or hematogenous seeding. Enterobacteriaceae are the predominant pathogens in acute and chronic bacterial prostatitis, but an increasing role of Enterococci has been reported. Many strains of these uropathogens exhibit the ability to form biofilm and multidrug- resistance. Sexually Transmitted Infections (STI) agents, in particular Chlamydia trachomatis and Mycoplasma genitalium, have been also considered as causative pathogens of chronic bacterial prostatitis. On the contrary the effective role in genital diseases of other "genital mycoplasmas" is still a much debated issue. Sexually Transmitted Infections agents should be investigated by molecular methods in both patient and sexual partner. "Next generation" investigations, such as cytokine analysis, cytological typing of immune cells could help stratifying the immune response. Epigenetic dysregulation of inflammatory factors should be investigated according to systemic and compartment-specific signals. The search for biomarkers should also include evaluation of hormonal pathways, as measurement of estrogen levels in semen. Antimicrobials are the first line agents for the treatment of bacterial prostatitis. The success of antimicrobial treatment depends on the antibacterial activity and the pharmacokinetic characteristics of the drug which must reach high concentrations in prostate secretion and prostate tissue. Acute bacterial prostatitis can be a serious infection with a potential risk for urosepsis For iInitial treatment of severely ill patients, intravenous administration of high doses of bactericidal antimicrobials, such as broad-spectrum penicillins, third-generation cephalosporins or fluoroquinolones, is recommended in combination with an aminoglycoside. Use of piperacillin-tazobactam and meropenem is justified in presence of multiresistant gramnegative pathogens. The antibiotic treatment of chronic prostatitis is currently based on the use of fluoroquinolones that, given for 2 to 4 weeks, cured about 70% of men with chronic bacterial prostatitis. For the treatment of Chlamydial prostatitis macrolides were shown to be more effective than fluoroquinolones, whereas no differences were observed in microbiological and clinical efficacy between macrolides and tetracyclines for the treatment of infections caused by intracellular pathogens. Aminoglycosides and fosfomycin could be considered as a therapeutic alternative for the treatment of quinolone resistant prostatitis. Use of alpha-blockers in CP/CPPS patients with urinary symptoms and analgesics +/- non steroidal anti-inflammatory drugs (NSAID), in presence of pain demonstrated a reduction of symptoms reduction and an improvement of quality of life, although long term use of NSAID is limited by side effect profile. However, the multimodal therapeutic regimen by contemporary use of alphablockers, antibiotics and anti-inflammatory showed a better control of prostatitis symptoms than single drug treatment. Novel therapeutic substances for the treatment of pain, such as the cannabinoid anandamide would be highly interesting to test. An alternative for the treatment of chronic prostatitis/chronic pelvic pain syndrome is phytotherapy, as primary therapy or in association with other drugs. Quercetin, pollen extract, extract of Serenoa repens and other mixtures of herbal extracts showed a positive effect on symptoms and quality of life without side effects. The association of CP/CPPS with alterations of intestinal function has been described. Diet has its effects on inflammation by regulation of the composition of intestinal flora and direct action on the intestinal cells (sterile inflammation). Intestinal bacteria (microbiota) interacts with food influencing the metabolic, immune and inflammatory response of the organism. The intestinal microbiota has protective function against pathogenic bacteria, metabolic function by synthesis of vitamins, decomposition of bile acids and production of trophic factors (butyrate), and modulation of the intestinal immune system. The alteration of the microbiota is called "dysbiosis" causing invasive intestinal diseases pathologies (leaky gut syndrome and food intolerances, irritable bowel syndrome or chronic inflammatory bowel diseases) and correlating with numerous systemic diseases including acute and chronic prostatitis. Administration of live probiotics bacteria can be used to regulate the balance if intestinal flora. Sessions of hydrocolontherapy can represent an integration to this therapeutic approach. Finally, microbiological examination of sexual partners can offer supplementary information for treatment.