INFECTIONS AFTER PROSTATE BIOPSY AND ANTIBIOTIC RESISTANCE

Trial Comparing a Combined Regimen of Amikacin and Ciprofloxacin to Ciprofloxacin Alone as Transrectal Prostate Biopsy Prophylaxis in the Era of High Fluoroquinolone-Resistant Rectal Flora

BACKGROUND

To investigate whether addition of amikacin to fluoroquinolone (FQ) antimicrobial prophylaxis reduces infections after transrectal ultrasound-guided prostate biopsy (TRUSPB).

METHODS

A total of 503 patients undergoing rectal swab were divided into three groups. Patients with FQ-sensitive rectal flora (group 1, n = 248) were administered ciprofloxacin before TRUSPB, and patients with FQ-resistant rectal flora were either administered ciprofloxacin (group 2, n = 97) or amikacin and ciprofloxacin (group 3, n = 158) before TRUSPB.

RESULTS

Based on the rectal swab, FQ resistance was 54.9%, and extended-spectrum β-lactamase (ESBL) positivity was 17.2%. The incidence of infectious complication in group 1 was 1.6%. Groups 2 and 3, with FQ-resistant rectal flora, tended to have increased infectious complications (5.2% and 4.4%, respectively) but the difference between those results is not statistically significant. The most common pathogens of infectious complications in patients with FQ-resistant rectal flora were FQ-resistant and ESBL-producing Escherichia coli. E. coli pathogens isolated in Group 3 were amikacin-susceptible species. The operation history and ESBL positivity of rectal flora increased the incidence of infectious complications (odds ratio [OR] = 3.68; P = 0.035 and OR = 4.02; P = 0.008, respectively). DM and antibiotics exposure were risk factors for FQ resistance (OR = 2.19; P = 0.002) and ESBL positivity of rectal flora (OR = 2.96; P = 0.005), respectively.

CONCLUSION

Addition of amikacin to ciprofloxacin prophylaxis could not reduce infectious complications in patients with FQ-resistant rectal flora. Despite the amikacin sensitivity of infectious complications, single-dose amikacin addition to ciprofloxacin prophylaxis has limitations.

Drug-Eluting Biopsy Needle as a Novel Strategy for Antimicrobial Prophylaxis in Transrectal Prostate Biopsy

Objectives:

To preclinically evaluate drug-eluting biopsy needles (patent pending WO2016118026) as a new potential way of antimicrobial prophylaxis for transrectal prostate biopsy.

Methods:

Twenty steel biopsy needles have been coated with polyvinyl alcohol, ciprofloxacin, and amikacin. Modified biopsy needles have been randomly divided into 3 groups (1:2:1 ratio). Needles from group I were immersed for 30 minutes in dedicated test tubes containing saline. Needles from group II were immersed (one by one) for 5 seconds in a set of 12 test tubes containing saline. Then, each solution was analyzed using high-performance liquid chromatography. The results were compared with the susceptibility break points for Escherichia coli. Group III was incubated with E coli strains on Mueller-Hinton plate and then the bacterial inhibition zones surrounding needles were measured.

Results:

The average concentration of antibiotics eluted from needles (group I) was 361.98 ± 15.36 µg/mL for amikacin and 63.87 ± 5.95 µg/mL for ciprofloxacin. The chromatographic analysis revealed the gradual release of both antibiotics from needles (group II). The concentration of amikacin released from needles exceeded the break-point value from first to ninth immersion. Ciprofloxacin concentration was higher than break-point value in all immersions. The average bacterial inhibition zone minor axis was 42 ± 5.7 mm (group III).

Conclusions:

The use of drug-eluting biopsy needle could be a new potential way of antimicrobial prophylaxis for transrectal prostate biopsy. This study confirmed its biological activity as well as the gradual release of antibiotics from its surface. Confirmation of its preventive role, in terms of infectious complications after transrectal prostate biopsy, has to be evaluated in a clinical trial.

Formalin disinfection of prostate biopsy needles may reduce post-biopsy infectious complications

BACKGROUND

We sought to determine whether formalin disinfection of prostate biopsy needles between cores reduces post-biopsy urinary tract infections (UTIs).

METHODS

We reviewed a single-surgeon experience of transrectal prostate biopsies from 2010 to 2014. Biopsies were performed in either an operative suite, where 10% formalin was used to disinfect the needle tip between each biopsy core, or an outpatient clinic, where formalin was not used. Our primary outcome was post-biopsy UTI rates, defined as a positive urine culture within 30 days of biopsy. Infection severity was characterized by the need for admission. Patient demographics, prostate size, prior biopsies, prior UTIs, pre-biopsy antibiotics and cultures and post-biopsy cultures were analyzed. Logistic regression was used to assess predictors of post-biopsy UTIs. Statistical significance was defined as P<0.05.

RESULTS

A total of 756 patients were included for analysis, including 253 who received formalin disinfection and 503 who did not. Of these, 32 patients (4.2%) experienced post-biopsy UTIs, with 8 requiring admission (all without formalin use). Infection rates were more than double in the group that did not receive formalin (5.2% vs 2.3%, P=0.085). More patients in the formalin group had undergone prior biopsies (73.9% vs 31.8%, P<0.001). On multivariable analysis, prior UTI (odds ratio (OR) 3.77, P=0.006) was a significant predictor for post-biopsy infection, whereas formalin disinfection trended towards a protective effect (OR 0.41, P=0.055).

CONCLUSION

Infectious complications following prostate biopsy may be mitigated by the use of formalin disinfection of the biopsy needle between cores.

Rapid Identification of Rectal Multidrug-resistant Escherichia coli Before Transrectal Prostate Biopsy

OBJECTIVE

To develop and evaluate a rapid multiplex-quantitative polymerase chain reaction (qPCR) to identify fecal carriers of multidrug-resistant extraintestinal pathogenic Escherichia coli (MDR-ExPEC) clonal groups.

METHODS

Men presenting for transrectal prostate biopsy (TPB) at the San Diego Veterans Affairs Medical Center underwent rectal culture immediately before TPB. Rectal swabs were streaked onto ciprofloxacin-supplemented (4 mg/L) MacConkey agar plates, identified, and susceptibility tested. The same swab was sent to the University of Washington for qPCR test (EST200) targeting 2 major MDR-ExPEC clonal groups--ST131 and ST69--that combined were expected to represent majority of fluoroquinolone (FQ)- and trimethoprim-sulfamethoxazole-resistant E coli. We calculate test characteristics including the area under the receiver operative curve (AUC).

RESULTS

We enrolled 104 men from 11/5/2013 to 6/10/2014. FQ-resistant E coli were cultured from 19.2% (20/104) of rectal swabs, and 26% (27/104) of all swabs were positive for EST200 by PCR. The test characteristics comparing the EST200 to the culture-based detection of FQ resistance were 75%, 86%, 94%, and 56%, respectively. The AUC was 0.84 for the EST200 to detect FQ resistance before TPB.

CONCLUSION

Compared to the reference standard rectal culture, EST200 was able to detect majority of FQ-resistant E coli on rectal swabs before prostate biopsy.

Quinolone prophylaxis in transrectal ultrasound guided prostate biopsy: an eight-year single center experience

We retrospectively evaluated the efficacy of prophylaxis with pipemidic acid and levofloxacin in transrectal ultrasound guided prostate biopsy (TRUSP-Bx). From January 2002 to December 2004, patients receiving oral pipemidic acid 500 mg twice daily for three days with or without a preoperative intravenous cefazolin 1 gm injection comprised group A. Between January 2005 and December 2009, patients receiving oral levofloxacin 500 mg one hour before biopsy comprised group B. We calculated the annual febrile urinary tract infection (fUTI) rates. Patients' characteristics, including age, prophylactic antibiotics, biopsy core numbers, pathologic results, PSA, and the spectrums and susceptibility of pathogens, were also evaluated. A total of 1313 (35.5%) patients belonged to group A, while 2381 (64.5%) patients belonged to group B. Seventy-three patients experienced postoperative infectious complications. There was a significant difference in the fUTI rate between groups A and B (3.7% versus 1.0%, P < 0.001). The yearly fUTI rates varied from 0.6 to 3.9% between 2002 and 2009. Of the 73 patients with fUTI, those receiving levofloxacin prophylaxis were more likely to harbor fluoroquinolone-resistant pathogens (P < 0.001). E. coli was the most common pathogen in both groups. Levofloxacin remains effective and appears superior to pipemidic acid based prophylaxis.

Intravenous piperacillin/tazobactam plus fluoroquinolone prophylaxis prior to prostate ultrasound biopsy reduces serious infectious complications and is cost effective

Infectious complications related to prostate ultrasound and biopsy have increased in the past decade with the emergence of increasing fluoroquinolone bacterial resistance. We investigated the addition of intravenous (iv) piperacillin/tazobactam immediately prior to prostate ultrasound and biopsy with standard fluoroquinolone prophylaxis to determine if it would decrease the incidence of serious infectious complications after prostate ultrasound and biopsy. Group 1 patients were a historic control of 197 patients who underwent prostate ultrasound and biopsy with standard fluoroquinolone prophylaxis. Group 2 patients, 104 patients, received standard fluoroquinolone prophylaxis and the addition of a single dose of iv piperacillin/tazobactam 30 minutes prior to prostate ultrasound and biopsy. There were ten serious bacterial infectious complications in group 1 patients. No patients in group 2 developed serious bacterial infections after prostate ultrasound and biopsy. There was approximately a 5% incidence of serious bacterial infection in group 1 patients. Subgroup analysis revealed an almost 2.5 times increased risk of infection in diabetes patients undergoing prostate ultrasound and biopsy. There was a 10% risk of serious bacterial infection in diabetics compared with a 3.8% risk group 1 nondiabetes patients. The addition of a single dose of iv piperacillin/tazobactam along with standard fluoroquinolone prophylaxis substantially reduces the risk of serious bacterial infection after prostate ultrasound and biopsy (P < 0.02).

Prevalence and significance of fluoroquinolone resistant Escherichia coli in patients undergoing transrectal ultrasound guided prostate needle biopsy

PURPOSE

We estimated the prevalence of fluoroquinolone resistant Escherichia coli in patients undergoing repeat transrectal ultrasound guided prostate needle biopsy and identified high risk groups.

MATERIALS AND METHODS

From January 2009 to March 2010 rectal swabs of 136 men from 3 institutions undergoing transrectal ultrasound guided prostate needle biopsy were obtained. There were 33 men with no previous biopsy who served as the controls. Participants completed questionnaires and rectal swab culture was obtained just before performing the prostate biopsy. Selective media was used to specifically isolate fluoroquinolone resistant E. coli and sensitivities were obtained. The patients were contacted via telephone 7 days after the procedure for a followup questionnaire.

RESULTS

A total of 30 patients had cultures positive for fluoroquinolone resistant bacteria for an overall rate of 22% (95% CI 15, 29). Patients with diabetes and Asian ethnicity had higher risks of resistant rectal flora colonization (OR 2.3 and 2.8, respectively). However, differences did not reach statistical significance (p = 0.09 and p = 0.08, respectively). Patients with no prior biopsy had a positive rate of 15% (5 of 33) compared to 24% (25 of 103) in those with 1 or more prior biopsies (OR 1.8, p = 0.27). Five patients (3.6%) had post-biopsy fever while only 1 of those patients had a positive rectal swab.

CONCLUSIONS

Using selective media to isolate fluoroquinolone resistant E. coli from the rectum before transrectal ultrasound guided prostate biopsy, we isolated organisms in 22% of patients with a wide resistance pattern. This protocol may be used to provide information regarding targeted antibiotic prophylaxis before transrectal prostate biopsies.

Neovesical-urethral anastomotic stricture successfully treated by ureteral dilation balloon catheter

Neovesical-urethral anastomotic stricture is a complication of orthotopic neobladder, with a reported incidence of 2.7% to 8.8%. Strictures of the neovesico-urethral anastomotic site can be treated with regular self-dilation, but high-grade strictures require a surgical procedure involving incision by electrocautery or cold knife. Here we describe a grade III neovesical-urethral anastomotic stricture after an orthotopic bladder substitution that was successfully treated by use of a ureteral dilation balloon catheter.

Prevalence of antimicrobial resistance in intestinal flora of patients undergoing prostatic biopsy: implications for prophylaxis and treatment of infections after biopsy

OBJECTIVE

To determine the prevalence of antimicrobial resistance in intestinal flora of patients undergoing transrectal ultrasonography (TRUS)-guided prostate biopsies (TGB) and to examine if this information is useful in selecting appropriate antimicrobial agents for prophylaxis and treatment of biopsy-associated infections.

PATIENTS AND METHODS

In 2007 and 2008, rectal swabs were cultured from patients before undergoing TGB. Antimicrobial sensitivity of coliforms to amikacin, ciprofloxacin and coamoxiclav was determined. Laboratory records were used to identify patients who had bacteraemia or significant bacteriuria within 30 days of the TGB and the antimicrobial sensitivity pattern of these organisms were compared to those from the rectal swab.

RESULTS

Of 592 patients who had TGB, 445 (75.1%) had a rectal swab beforehand; 0.2%,10.6% and 13.3% of the coliforms were resistant to amikacin, ciprofloxacin and coamoxiclav, respectively. After TGB, six patients presented with urinary tract infections (UTI) and two with bacteraemia. All the infections were caused by coliforms except one UTI which was caused by ciprofloxacin-sensitive Pseudomonas aeruginosa. The blood culture isolates were sensitive to amikacin but resistant to ciprofloxacin and coamoxiclav. All the coliforms in the urine were resistant to ciprofloxacin but sensitive to coamoxiclav. Urine isolates were not tested for amikacin sensitivity. There was a strong correlation between the antimicrobial sensitivity of the coliforms from the rectal swabs and those cultured from urine or blood in both patients for amikacin, six of eight for ciprofloxacin and seven of eight for coamoxiclav.

CONCLUSIONS

Our study shows that in the coliforms in the bowel flora of our local population there is a relatively high level of resistance to ciprofloxacin and coamoxiclav, and very low level of resistance to amikacin. As there was a strong correlation between the antimicrobial sensitivity of organisms causing infections after TGB and those isolated from the rectal swabs, we conclude that rectal swab cultures before TGB provide useful evidence for selecting appropriate antimicrobials for prophylaxis and treatment of TGB-associated infections.