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Bacterial Prostatitis: Incidence in the Obstructive Prostate
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,Jot~R.1'."-L
i:o,
URo~.uc;y
Copyright © 197:S by The YFilliarns &
1/1/ilkins
Printed
Co,
Octo:Jer
V.S.i5_
BACTERIAL PROSTATITIS: INCIDENCE IN THE OBSTRUCTIVE PROSTATE RALPH R. LANDES AND THOMAS N. FRENCH
From the Danville Urologic Clinic and the Memorial Hospital, Danville, Virginia
The obstructing prostate is the most common contributive cause of urinary tract infection in elderly men. Once established, the infected urine bathes the prostatic urethra and the orifices of the prostatic ducts, exposing the gland to infection by reflux and direct extension. Therefore, one might reasonably predict that bacterial prostatitis would be common in the obstructing prostate and, once present, might be difficult to eradicate from its tortuous racemose glands. This prediction might be reinforced by the frequent finding of large numbers of leukocytes and macrophages in expressed prostatic secretions and by the histologic presence of acute and chronic inflammatory changes, at times quite intense, in a large proportion of surgically removed prostates. In addition, the prostate has been reported as singularly impermeable to effective penetration by most antibiotics, thus contributing to resistant infections. 1 This is in sharp contrast to the urinary conduits which are bathed and perfused antibacterial concentrations often more than 100 times that of the blood. The concept of the prostate as a harborer of resistant infection has been emphasized recently and, indeed, these supposedly resistant prostatic foci have been indicted as the most common cause of recurrent urinary tract infection in male subjects: that urinary tract infection, which may respond promptly to antibacterial therapy, recurs because of reseeding unaffected bacterial foci in the prostate. 2 • 3 The study reported herein was designed to test these concepts and to answer the questions: 1) How common is bacterial prostatitis in patients with obstructing prostates? 2) What is the frequency of prostatitis in patients with sterile urine as compared to those with infected urine? 3) How common is bacterial prostatitis in patients in whom bacteriuria has been eradicated Are there, in fact, bacterial foci which survive antibacterial therapy and which await an infections'./ to
METHODS AND MATERIALS
Urine was obtained for bacterial culture at the beginning of 203 successive trans urethral. prostatic resections (TURPs). At mid operation, after many flushings of the bladder by the irrigating fluid, chips of prostate were obtained (2 to 3 gm.) from several sites and were homogenized and cultured for bacteria (see table). Of these patients, 111 had not received recent antibiotic therapy. These patients were afebrile with minimal or no symptoms of infection, although many had pyuria and residual urine. Of these 76 had sterile urine at the time of operation while' 35 had asymptomatic bacteriuria. The remaining 92 patients had received preoperative antibacterial therapy. All had symptomatic bacteriuria prior to therapy: fever, gross pyuria, strangury, upper tract ectasia and so on. These patients were operated upon after subsidence of the systemic symptoms but without regard to the presence of bacteriuria. Of these, 43 remained bacteriuric at the time of operation and 49 had become abacte:riuric. RESULTS
Patients who did not receiue preoperatiue antibacterial therapy. None of the cultures of prostatic tissue from the 76 patients with sterile urine at the time of operation yielded pathogens. Twenty-five per cent (9) of the cultures of prostatic chips from the 35 patients with asymptomatic bacteriuria yielded bacteria. Patients who receiued preoperatiue antibacterial therapy. Of the 92 patients treated with antibiotics Bacterial cultures of homogenized prostatic tissue of 203 patients undergoing TURP*
No
Pts. With Bacterial Pros ta ti tis No.(%)
76
0 (OJ
3t,
9 (25)
49 4:l
3 (6) 8 (19)
antibiotics: (asymp-
Accepted for publication April 6, 1973. This work was supported m part by a grant from the Eli Lilly Research Laboratories and from the Memonal Hospital Urological Research Fund. . . 1 Meares, E. M. and Stamey, T. k:_ Bactenolog1_c localization patterns in bacterial prostat1t1s and urethntis. Invest. Urol., 5: 492, 1968. 2 Stamey, T. A., Me_ares, E. M,.,_ Jr. and Wi~nin~ham 1 D. G.: Chronic bacterial prostatit1s and the d1ffus1on or drugs into prostatic fluid. J. Urol., Hl3: 187, 1970. 3 Stamey, T. A.: Urinary Infect10ns. Baltimore: The Williams & Wilkins Co., pp. 161-188, 1972.
No. Pts.
tomatic Treated with preop. antibiotics (symptomatically bacteriuric): Sterile urine at operation Infected urine at operation
* Two to 3 gm. prostatic chips homogenized in 9 ml. sterile saline. One ml. homogenate is streaked on a blood agar plate, 0.1 ml. on chocolate agar, phenolethyl alcohol agar and eosin methylene blue plates; 0.1 cc homogenate is innoculated into thioglycolate media. Also, a Gram stained slide of homogenate is examined. Growth of any colonies is reported as positive,
427
428
LANDES AND FRENCH
for symptomatic bacteriuria, 49 were abacteriuric at the time of operation; cultures from prostatic chips in 6 per cent (3) of these patients yielded pathogens and 94 per cent (46) were negative. Despite preoperative antibacterial therapy, 43 patients remained bacteriuric (but asymptomatic). Cultures of prostatic tissue from 8 of these (19 per cent) yielded pathogens.
fully treated severely bacteriuric patient with prostatism. Prior to therapy these patients obviously had an incidence of prostatic infection more than the 25 per cent of asymptomatic bacteriurics. A short period of appropriate antibacterial therapy reduced the incidence to 6 per cent. Therefore, we conclude that the infected prostate responds well to antibacterial therapy.
DISCUSSION
CONCLUSIONS
Our findings indicate that the prostate rarely harbors infection in the absence of infected urine. Certainly elderly men with prostatism could be expected to have prostatic foci of infection if this entity is at all common in the absence of bacteriuria. Yet none of our patients without a recent bout of bacteriuria had prostatic infection. Our data also indicate that the obstructing prostate is relatively resistant to urinary tract infection. Seventyfive per cent of the untreated bacteriuric patients and 81 per cent of the unsuccessfully treated bacteriuric patients remained free of prostatitis despite constant exposure to infected urine. The frequency of prostatic infection would certainly be greater among untreated symptomatic bacteriurics but it is obvious that this group could not be operated upon in the face of severe untreated infection in order to obtain tissue for bacterial culture. The most significant finding in this study is the low incidence of prostatic infection in the success-
No prostatic tissue bacteria were found among untreated patients with sterile urine. Bacterial prostatitis in patients with sterile urine did not exist. Only 25 per cent of the prostatic tissue cultures from asymptomatic untreated bacteriurics yielded pathogens. Only 19 per cent of the prostatic cultures of previously symptomatic bacteriurics, treated with antibacterials until they become asymptomatic but still bacteriuric, yielded bacteria. These data indicate that the obstructive prostate is quite resistant to the urinary tract infection it initiates and to which it is exposed. Cultures of prostatic tissue from patients with severe urinary mfections which respond to appropriate antibacterial therapy and who have sterile urine at the time of operation rarely yield bacteria (3 of 49). This fact indicates that the infected prostate responds well to appropriate antibacterial therapy. Smoldering bacterial prostatitis is an uncommon entity among elderly men with prostatism.
,Jot~R.1'."-L
i:o,
URo~.uc;y
Copyright © 197:S by The YFilliarns &
1/1/ilkins
Printed
Co,
Octo:Jer
V.S.i5_
BACTERIAL PROSTATITIS: INCIDENCE IN THE OBSTRUCTIVE PROSTATE RALPH R. LANDES AND THOMAS N. FRENCH
From the Danville Urologic Clinic and the Memorial Hospital, Danville, Virginia
The obstructing prostate is the most common contributive cause of urinary tract infection in elderly men. Once established, the infected urine bathes the prostatic urethra and the orifices of the prostatic ducts, exposing the gland to infection by reflux and direct extension. Therefore, one might reasonably predict that bacterial prostatitis would be common in the obstructing prostate and, once present, might be difficult to eradicate from its tortuous racemose glands. This prediction might be reinforced by the frequent finding of large numbers of leukocytes and macrophages in expressed prostatic secretions and by the histologic presence of acute and chronic inflammatory changes, at times quite intense, in a large proportion of surgically removed prostates. In addition, the prostate has been reported as singularly impermeable to effective penetration by most antibiotics, thus contributing to resistant infections. 1 This is in sharp contrast to the urinary conduits which are bathed and perfused antibacterial concentrations often more than 100 times that of the blood. The concept of the prostate as a harborer of resistant infection has been emphasized recently and, indeed, these supposedly resistant prostatic foci have been indicted as the most common cause of recurrent urinary tract infection in male subjects: that urinary tract infection, which may respond promptly to antibacterial therapy, recurs because of reseeding unaffected bacterial foci in the prostate. 2 • 3 The study reported herein was designed to test these concepts and to answer the questions: 1) How common is bacterial prostatitis in patients with obstructing prostates? 2) What is the frequency of prostatitis in patients with sterile urine as compared to those with infected urine? 3) How common is bacterial prostatitis in patients in whom bacteriuria has been eradicated Are there, in fact, bacterial foci which survive antibacterial therapy and which await an infections'./ to
METHODS AND MATERIALS
Urine was obtained for bacterial culture at the beginning of 203 successive trans urethral. prostatic resections (TURPs). At mid operation, after many flushings of the bladder by the irrigating fluid, chips of prostate were obtained (2 to 3 gm.) from several sites and were homogenized and cultured for bacteria (see table). Of these patients, 111 had not received recent antibiotic therapy. These patients were afebrile with minimal or no symptoms of infection, although many had pyuria and residual urine. Of these 76 had sterile urine at the time of operation while' 35 had asymptomatic bacteriuria. The remaining 92 patients had received preoperative antibacterial therapy. All had symptomatic bacteriuria prior to therapy: fever, gross pyuria, strangury, upper tract ectasia and so on. These patients were operated upon after subsidence of the systemic symptoms but without regard to the presence of bacteriuria. Of these, 43 remained bacteriuric at the time of operation and 49 had become abacte:riuric. RESULTS
Patients who did not receiue preoperatiue antibacterial therapy. None of the cultures of prostatic tissue from the 76 patients with sterile urine at the time of operation yielded pathogens. Twenty-five per cent (9) of the cultures of prostatic chips from the 35 patients with asymptomatic bacteriuria yielded bacteria. Patients who receiued preoperatiue antibacterial therapy. Of the 92 patients treated with antibiotics Bacterial cultures of homogenized prostatic tissue of 203 patients undergoing TURP*
No
Pts. With Bacterial Pros ta ti tis No.(%)
76
0 (OJ
3t,
9 (25)
49 4:l
3 (6) 8 (19)
antibiotics: (asymp-
Accepted for publication April 6, 1973. This work was supported m part by a grant from the Eli Lilly Research Laboratories and from the Memonal Hospital Urological Research Fund. . . 1 Meares, E. M. and Stamey, T. k:_ Bactenolog1_c localization patterns in bacterial prostat1t1s and urethntis. Invest. Urol., 5: 492, 1968. 2 Stamey, T. A., Me_ares, E. M,.,_ Jr. and Wi~nin~ham 1 D. G.: Chronic bacterial prostatit1s and the d1ffus1on or drugs into prostatic fluid. J. Urol., Hl3: 187, 1970. 3 Stamey, T. A.: Urinary Infect10ns. Baltimore: The Williams & Wilkins Co., pp. 161-188, 1972.
No. Pts.
tomatic Treated with preop. antibiotics (symptomatically bacteriuric): Sterile urine at operation Infected urine at operation
* Two to 3 gm. prostatic chips homogenized in 9 ml. sterile saline. One ml. homogenate is streaked on a blood agar plate, 0.1 ml. on chocolate agar, phenolethyl alcohol agar and eosin methylene blue plates; 0.1 cc homogenate is innoculated into thioglycolate media. Also, a Gram stained slide of homogenate is examined. Growth of any colonies is reported as positive,
427
428
LANDES AND FRENCH
for symptomatic bacteriuria, 49 were abacteriuric at the time of operation; cultures from prostatic chips in 6 per cent (3) of these patients yielded pathogens and 94 per cent (46) were negative. Despite preoperative antibacterial therapy, 43 patients remained bacteriuric (but asymptomatic). Cultures of prostatic tissue from 8 of these (19 per cent) yielded pathogens.
fully treated severely bacteriuric patient with prostatism. Prior to therapy these patients obviously had an incidence of prostatic infection more than the 25 per cent of asymptomatic bacteriurics. A short period of appropriate antibacterial therapy reduced the incidence to 6 per cent. Therefore, we conclude that the infected prostate responds well to antibacterial therapy.
DISCUSSION
CONCLUSIONS
Our findings indicate that the prostate rarely harbors infection in the absence of infected urine. Certainly elderly men with prostatism could be expected to have prostatic foci of infection if this entity is at all common in the absence of bacteriuria. Yet none of our patients without a recent bout of bacteriuria had prostatic infection. Our data also indicate that the obstructing prostate is relatively resistant to urinary tract infection. Seventyfive per cent of the untreated bacteriuric patients and 81 per cent of the unsuccessfully treated bacteriuric patients remained free of prostatitis despite constant exposure to infected urine. The frequency of prostatic infection would certainly be greater among untreated symptomatic bacteriurics but it is obvious that this group could not be operated upon in the face of severe untreated infection in order to obtain tissue for bacterial culture. The most significant finding in this study is the low incidence of prostatic infection in the success-
No prostatic tissue bacteria were found among untreated patients with sterile urine. Bacterial prostatitis in patients with sterile urine did not exist. Only 25 per cent of the prostatic tissue cultures from asymptomatic untreated bacteriurics yielded pathogens. Only 19 per cent of the prostatic cultures of previously symptomatic bacteriurics, treated with antibacterials until they become asymptomatic but still bacteriuric, yielded bacteria. These data indicate that the obstructive prostate is quite resistant to the urinary tract infection it initiates and to which it is exposed. Cultures of prostatic tissue from patients with severe urinary mfections which respond to appropriate antibacterial therapy and who have sterile urine at the time of operation rarely yield bacteria (3 of 49). This fact indicates that the infected prostate responds well to appropriate antibacterial therapy. Smoldering bacterial prostatitis is an uncommon entity among elderly men with prostatism.