infectious adverse events after transrectal prostate biopsy ( tpbx ) have been increasing , and even septic and fatal cases have been reported . fluoroquinolones have long been used for prophylactic administration owing to their good efficacy and high concentration in the prostate after dosing . however , especially in urinary tract infections ( utis ) , fluoroquinolone - resistant escherichia coli ( fqre ) has been rapidly increasing . resistance ratios to levofloxacin ( lvfx ) have jumped up to 5% to 20% . because tpbx is increasingly used to detect prostate cancer , adverse events are a growing concern . another resistant strain , extended - spectrum beta - lactamase ( esbl)-producing e. coli , also poses difficulties for treatment . some kinds of carbapenems are available for this resistant strain , but it has the potential to be an intractable infection . some authors previously reported a case of prostatitis caused by esbl - producing e. coli and it could be treated by imipenem and tazobactam / piperacillin ( taz / pipc ) . beta - lactamase inhibitors have generally been combined with penicillins partly because this combination can bring out the antibiotic activity fully and prevent the emergence of antibiotic - resistant strains . taz / pipc ( zosin ) is an intravenous antibiotic agent consisting of 4 g of piperacillin and 0.5 g of tazobactam at an 8:1 ratio and is a modification of tazosin , which was used before and consisted of 2 g of piperacillin and 0.5 g of tazobactam . penicillins combined with beta - lactamase inhibitors such as taz / pipc are widely used to treat utis and show good efficacy for e. coli , including fqre and esbl - producing e. coli , and are recommended for tpbx in the japanese uti association guidelines especially in high risk group . in this study , we examined whether taz / pipc plus lvfx could suppress infectious adverse events after tpbx . we performed a study of 201 consecutive men scheduled for tpbx because of an elevated prostate - specific antigen ( psa ) level , an abnormal digital rectal examination ( dre ) , or abnormal magnetic resonance imaging ( mri ) or transrectal ultrasound ( trus ) findings . all biopsies were performed with an 18-gauge bard max core disposable biopsy instrument biopsy needle ( c.r . convington , ga , usa ) in conjunction with a medical ultrasound console ( aloka ssd-2000 , aloka co. ltd . , acetylsalicylic acid or oral anticoagulant agents were stopped appropriately before tpbx with the approval of the prescribing physician as a rule . no preparatory cleansing enemas were used , and the tpbx procedure was performed with only sacral anesthesia with 1% lidocaine and povidone iodine sterilization just before the tpbx . for prophylactic antibiotic medication , each patient received taz / pipc 4.5 g i.v . and lvfx 100 mg or 500 mg taken orally 30 minutes before tpbx . patients continued to take 100 mg after every meal or 500 mg lvfx once a day for 3 days with or without styptic or anti - plasmin . the dose of lvfx was changed to 500 mg from 300 mg per day from august 2009 in this study . patients were examined for infectious adverse events after tpbx and white blood cell ( wbc ) counts ( /mm ) and c - reactive protein ( crp ) ( g / ml ) in plasma were measured before and 1 day after tpbx . all patients undergoing tpbx were hospitalized on the day of tpbx and were discharged the next day if there were no adverse events requiring further hospitalization . the day after tpbx , patients ' laboratory data were checked including wbc and crp in serum . if a patient had symptoms from infectious complications such as chills or fever greater than 38.0 after tpbx , he was asked to return to the emergency department . he immediately underwent a urinalysis , urine culture , and blood analysis , and any other complications were recorded . as a rule , if acute prostatitis was diagnosed , the patient was hospitalized and treated with the third- or fourth - generation cephalosporin or carbapenem i.v . , and statistical analysis was performed by use of student 's t - test or welch 's t - test or fisher 's exact test with the jstat - java virtual machine statistics monitoring tool ( sun microsystems , inc . , we performed a study of 201 consecutive men scheduled for tpbx because of an elevated prostate - specific antigen ( psa ) level , an abnormal digital rectal examination ( dre ) , or abnormal magnetic resonance imaging ( mri ) or transrectal ultrasound ( trus ) findings . all biopsies were performed with an 18-gauge bard max core disposable biopsy instrument biopsy needle ( c.r . convington , ga , usa ) in conjunction with a medical ultrasound console ( aloka ssd-2000 , aloka co. ltd . , acetylsalicylic acid or oral anticoagulant agents were stopped appropriately before tpbx with the approval of the prescribing physician as a rule . no preparatory cleansing enemas were used , and the tpbx procedure was performed with only sacral anesthesia with 1% lidocaine and povidone iodine sterilization just before the tpbx . for prophylactic antibiotic medication , each patient received taz / pipc 4.5 g i.v . and lvfx 100 mg or 500 mg taken orally 30 minutes before tpbx . patients continued to take 100 mg after every meal or 500 mg lvfx once a day for 3 days with or without styptic or anti - plasmin . the dose of lvfx was changed to 500 mg from 300 mg per day from august 2009 in this study . patients were examined for infectious adverse events after tpbx and white blood cell ( wbc ) counts ( /mm ) and c - reactive protein ( crp ) ( g / ml ) in plasma were measured before and 1 day after tpbx . all patients undergoing tpbx were hospitalized on the day of tpbx and were discharged the next day if there were no adverse events requiring further hospitalization . the day after tpbx , patients ' laboratory data were checked including wbc and crp in serum . if a patient had symptoms from infectious complications such as chills or fever greater than 38.0 after tpbx , he was asked to return to the emergency department . he immediately underwent a urinalysis , urine culture , and blood analysis , and any other complications were recorded . as a rule , if acute prostatitis was diagnosed , the patient was hospitalized and treated with the third- or fourth - generation cephalosporin or carbapenem i.v . , and blood and urine culture tests were performed . statistical analysis was performed by use of student 's t - test or welch 's t - test or fisher 's exact test with the jstat - java virtual machine statistics monitoring tool ( sun microsystems , inc . , one of 201 patients ( 0.50% ) had a febrile complication such as acute prostatitis after tpbx . our data from laboratory tests done the day after tpbx , including serum wbc count and crp , did not demonstrate a significant rise in these variables compared with the pre - tpbx data as shown in table 2 ( p>0.05 ) . the serum wbc count before and after tpbx ( day 1 ) was 6,1231,655 and 6,4271,898 ( /mm ) , respectively . serum crp before and after tpbx ( day 1 ) was 0.17020.4020 and 0.26020.4534 ( g / ml ) , respectively ( table 2 ) . no patients showed obvious side effects from this regimen ( taz / pipc plus lvfx ) . a case with febrile complication had fever ( 37.6 ) from the night of tpbx and his serum wbc and crp rose up ( 18,100/mm and 4.1 g / ml , respectively ) on the next day . doripenem 0.5 g / day and his symptoms and laboratory data reacted very well and improved . in addition , we compared lvfx 500 mg with lvfx 300 mg in the taz / pipc plus lvfx regimen ; however , there were no significant differences between the two groups regarding the febrile complication rate ( p>0.05 ) or change in serum wbc and crp before and after tpbx ( table 3 ) . tpbx is a test for the detection of prostate cancer and most patients have cancer - negative results in general ; therefore , severe adverse events must be prevented . recently , the ratio of infectious complications after tpbx has risen and even septic or fatal cases have been reported . one of the main reasons for this unfortunate fact is the increase of antibiotic - resistant enterobacteriaceae . naturally , e. coli is one of the main targets to suppress in this procedure , and infectious adverse events may be partly caused by antibiotic - resistant bacteria . fluoroquinolones are often used for prophylactic medication in tpbx , partly because they are retained at high concentrations in the prostate as mentioned above ; however , fluoroquinolone - resistant e. coli are spreading , especially in uti . a guideline for prophylactic antibiotic medication for tpbx in 2006 and 2007 recommends fluoroquinolones in low - risk groups and taz / pipc in high - risk groups . however , infectious complications and septic cases after tpbx increased after the publication of this guideline . our regimen was set for the following reasons : 1 ) good efficacy of taz / pipc for e. coli including beta - lactamase - producing bacteria , 2 ) good intra - prostate concentrations and permeability of lvfx , 3 ) the data on taz / pipc alone mentioned below , and 4 ) the higher resistance ratio of e. coli to lvfx in our previous study ( data not shown ) than before , and 5 ) the higher ratio of esbl - producing e. coli among all e. coli isolated recently than before in our institution ( data not shown ) . guidelines need to be updated to reflect the current antibiotic susceptibilities of emergent bacterial strains . as reported in the literature , the ratios of febrile infectious complications range from 0.51% to 7.27% , which suggests that our method could be one of the recommendations for this purpose . in addition , our previous method [ lvfx plus aminoglycoside ( isepamicin ) ] has shown good efficacy for this purpose ; however , partly because of the spread of resistant strains , the previous method should be reconsidered and revised by the current data . for instance , kato et al reported a case of septic shock caused by fluoroquinolone - resistant e. coli after tpbx , and carlson et al reported multi - drug - resistant e. coli urosepsis cases including a death case following tpbx . in addition , kim et al reported 923 cases of tpbx and concluded that almost cases of acute prostatitis ( 2.0% ) were caused by fluoroquinolone - resistant e. coli . this may suggest that the trend in infection and resistant strains could change and should be monitored and the guidelines revised if necessary . regarding antibiotic - resistant e. coli , esbl - producing e. coli have been reported as problematic to treat even in utis as mentioned above . lee et al reported the prevalence of esbl - producing uropathogens in uti patients , and the overall prevalence ratio was 12.6% in their 3-year study . this trend is apparently growing and raises some doubt as to whether we can decrease the dose of taz / pipc or lvfx for future 's study . our laboratory data for serum wbc and crp demonstrate that our regimen offers good efficacy for suppressing inflammation and infectious adverse events after tpbx . our ratio of infectious complications after tpbx was 0.50% , indicating its suitability even for high - risk patients . our next step will , as mentioned above , be to consider reducing the dose of taz / pipc and lvfx to once each on the day of tpbx ( just before the procedure ) for low - risk patients , while strictly monitoring for resistant strains . some authors report the efficacy of oral antibiotics for this purpose , but it might be necessary to combine intravenous antibiotics for suppression of septic cases . because tpbx detects prostate cancer in only 20% to 30% of cases , and because most of these patients have organ - confined cancer that may not cause early death , serious complications from the diagnostic procedure itself should be regarded as unacceptable as mentioned above . our results of only one febrile complication in 201 consecutive cases and no influence on infection - related laboratory data ( wbc and crp ) support an updated methodology for prophylactic medication . guidelines need to be updated regularly , because long repetition of a single recommendation may lead to widespread emergence of resistant bacterial strains . in general our data definitely showed a lower infectious complication ratio after tpbx , even though direct comparison could not be done because of the difference in core number , compared with the regimen of taz / pipc alone ( 13.5 g per day , once daily ) as used in kobe university hospital [ 7/180 : 3.89% in 10 ( sextant+2 transitional zone+2 far lateral peripheral zone ) cores ; data not shown ] . in addition , the data analyzed to observe an effect of lvfx dosing ( 300 mg or 500 mg per day as shown in table 3 ) suggested that our taz / pipc plus lvfx protocol was not affected by lvfx doses . in addition , the tpbx cases from kobe university hospital reported here included low - risk patients because the data were from consecutive tpbx cases . moreover , our previous regimen and study   was performed from 2003 to 2008 , and the high prevalence of esbl - producing e. coli was reported from the study done from 2007 to 2009 . taken together , these data suggest that our current regimen could be considered as one of the recommendations for not only high - risk patients but also non - high - risk patients . even though we showed good efficacy , this study may have limitations and further comparison study with the same patient group , study period , and method may be required . this single - arm study was also performed to confirm not only the effect of this regimen but also the safety for patients without any severe side effects . taz / pipc plus fluoroquinolones can be considered a valuable prophylactic regimen for preventing infectious complications in tpbx . taz / pipc plus fluoroquinolones is one of the options for prophylactic antimicrobial administration in tpbx , especially in high - risk groups .