The modern era struvite stone: patterns of urinary ... AWS
The modern era struvite stone: patterns of urinary infection and colonization Haresh Thummar,Adam De Fazio, Piruz Motamedinia, Gina Badalato, Ruslan Korets, Mantu Gupta
Introduc*on: • While observa-onal studies from 1970s and 1980s demonstrated a strong associa-on between struvite stones and urea-‐spli>ng organisms, subsequent work in the 1990s reported a weakening of this associa-on • This change prompted considera-on of number of explana-ons, including (1) fluoroquinolone mediated stone steriliza-on and (2) struvite forma-on in the absence of tradi-onal urea-‐ spli>ng organisms • Since the last major observa-onal study was published 20 years ago, we sought to examine whether this observed trend has con-nued while offering a modern assessment of struvite stone infec-on paMerns
Methods: • We retrospec-vely iden-fied pa-ents who underwent PCNL between February 2009 and August 2013 • Extracted stones were sent for composi-on analysis and stone culture • Urine samples were collected both preopera-vely and intraopera-vely • All subjects were started on preopera-ve an-bio-cs • Stones were classified as struvite or non-‐struvite based on the presence of magnesium ammonium phosphate • Isolated organisms were classified as either urea-‐ spli>ng (US) or non-‐urea-‐spli>ng based on the findings of previously published studies of organism specific urease ac-vity • For struvite formers, addi-onal clinical data was gathered regarding UTI risk factors, an-bio-c exposure prior to ini-al presenta-on and urine culture results from the 12 months prior to PCNL
Table 3 – Clinical Characteris*cs of Struvite Formers
Figure 1 -‐ Struvite Stone Cultures – Results from 7 Previous Studies (1973-‐1995)
Recurrent UTI, no. (%) UTI Risk Factors, no. (%) All Neurogenic bladder Foreign Body Disease State (HIV, DM) Obstruc-on Anatomic Abnormality Reflux An*bio*c Tx, no. (%) Preop Prior to Ini-al Office Visit
100%
Results:
33 (83) 29 (73) 11 (28) 10 (25) 9 (23) 8 (20) 6 (15) 2 (5) 40 (100) 30 (75)
Non-‐ Struvite
p-‐value
Pts, no. (%) 480 (100) 42 (9)
438 (91)
-‐-‐-‐
Age, mean 55
53
56
0.341
• Overall 70% of struvite stone cultures were posi-ve (vs. 24% , p < 0.001) while 30% grew urea-‐spli>ng organisms (vs. 10%, p ng organisms (vs. 10%, p ng organism • Considering the 12 sterile struvite stones, 8 (67%) were associated with at a posi-ve urine culture and all 12 were associated with a history of recurrent UTI or a known UTI risk factor
Sex, no. 240 (50) female (%)
34 (81)
206 (47)
< 0.001
Conclusions:
90% % Posi-ve (All Organisms)
80%
% Posi-ve (Urea-‐Spli>ng Only)
70% 60% 50% 40% 30% 20% 10% 0% Thompson and Stamey* (1973)
Fowler (1984)
Lewi McCartney (1984) (1985)
Bratell (1990)
Hugosson* (1990)
Gault (1995)
Figure 2 – Struvite Stone Culture Results
* Studies included both intrarenal and extrarenal stones
25% 20%
Table 1 – Demographics of En*re Sample and Comparison of Struvite and Non-‐Struvite Formers All
Struvite
15% 10% 5% 0%
Table 4 – Profiles of Subjects with Sterile Struvite Stones Table 2 – Culture Results for En*re Sample and Comparison of Struvite and Non-‐Struvite Stones Stone Cx -‐ All organisms no. pos (%) Stone Cx – US Only no. pos (%) Preop Urine Cx – All organisms no. pos (%) Preop Urine Cx – US Only no. pos (%) Prev Urine Cx -‐ All organisms no. pos (%) Prev Urine Cx – US Only no. pos (%)
Struvite Non-‐Struvite p-‐value 28 (70) 95 (24) < 0.001 12 (30)
40 (10)
< 0.001
23 (56)
85 (22)
< 0.001
13 (32)
38 (10)
< 0.001
24 (86) 15 (54)
-‐-‐-‐ -‐-‐-‐
-‐-‐-‐ -‐-‐-‐
Previous Previous UCx Pt. # Recurrent UTI Risk Factors ABX (Sex) UTI Neurogenic bladder N P. aeruginosa 3 (F) Y
Preop UCx
Intraop UCx
No growth
No growth
Retroperitoneal mass N
E. coli
No growth
No growth
-‐-‐-‐
No growth
No growth
No growth
Calyceal Diver-culum Y
K. pneumoniae
K. pneumoniae
No growth
Neurogenic bladder
Y
P. mirabilis
No growth
No growth
-‐-‐-‐
Y
No growth
No growth
No growth
DM
Y
E. coli
E. coli
No growth
DM
N
No growth
No growth
No growth
Neurogenic bladder
Y
S. agalac6ae
No growth
No growth
Bifid collec-ng system -‐-‐-‐
Y
-‐-‐-‐
No growth
No growth
Y
S. saprophy6cus
No growth
No growth
Pregnancy
Y
P. mirabilis
No growth
No growth
10(F) 12(M) 14 (F) 15 (F) 17 (F) 18 (F)
Y Y Y N Y Y
22 (F) N 28 (F) Y 30 (F) Y 31 (F) Y 36 (F) Y
Y
• While culture results, demographic data and clinical history suggest a significant associa-on between struvite stones and infec-on, urea-‐ spli>ng organisms could not be iden-fied in associa-on with all struvite stones in this series • The finding of sterile struvite stones suggests possible stone steriliza-on, especially in the context of extensive preopera-ve an-bio-c exposure • The presence of tradi-onally non-‐urea-‐spli>ng organisms on stone culture encourages 1) reevalua-on of their urease-‐producing poten-al, 2) considera-on of a contributory role in struvite forma-on and 3) expansion of an-bio-c coverage for both Enterococcus spp. and E. coli in the management of suspected struvite stones
Introduc*on: • While observa-onal studies from 1970s and 1980s demonstrated a strong associa-on between struvite stones and urea-‐spli>ng organisms, subsequent work in the 1990s reported a weakening of this associa-on • This change prompted considera-on of number of explana-ons, including (1) fluoroquinolone mediated stone steriliza-on and (2) struvite forma-on in the absence of tradi-onal urea-‐ spli>ng organisms • Since the last major observa-onal study was published 20 years ago, we sought to examine whether this observed trend has con-nued while offering a modern assessment of struvite stone infec-on paMerns
Methods: • We retrospec-vely iden-fied pa-ents who underwent PCNL between February 2009 and August 2013 • Extracted stones were sent for composi-on analysis and stone culture • Urine samples were collected both preopera-vely and intraopera-vely • All subjects were started on preopera-ve an-bio-cs • Stones were classified as struvite or non-‐struvite based on the presence of magnesium ammonium phosphate • Isolated organisms were classified as either urea-‐ spli>ng (US) or non-‐urea-‐spli>ng based on the findings of previously published studies of organism specific urease ac-vity • For struvite formers, addi-onal clinical data was gathered regarding UTI risk factors, an-bio-c exposure prior to ini-al presenta-on and urine culture results from the 12 months prior to PCNL
Table 3 – Clinical Characteris*cs of Struvite Formers
Figure 1 -‐ Struvite Stone Cultures – Results from 7 Previous Studies (1973-‐1995)
Recurrent UTI, no. (%) UTI Risk Factors, no. (%) All Neurogenic bladder Foreign Body Disease State (HIV, DM) Obstruc-on Anatomic Abnormality Reflux An*bio*c Tx, no. (%) Preop Prior to Ini-al Office Visit
100%
Results:
33 (83) 29 (73) 11 (28) 10 (25) 9 (23) 8 (20) 6 (15) 2 (5) 40 (100) 30 (75)
Non-‐ Struvite
p-‐value
Pts, no. (%) 480 (100) 42 (9)
438 (91)
-‐-‐-‐
Age, mean 55
53
56
0.341
• Overall 70% of struvite stone cultures were posi-ve (vs. 24% , p < 0.001) while 30% grew urea-‐spli>ng organisms (vs. 10%, p ng organisms (vs. 10%, p ng organism • Considering the 12 sterile struvite stones, 8 (67%) were associated with at a posi-ve urine culture and all 12 were associated with a history of recurrent UTI or a known UTI risk factor
Sex, no. 240 (50) female (%)
34 (81)
206 (47)
< 0.001
Conclusions:
90% % Posi-ve (All Organisms)
80%
% Posi-ve (Urea-‐Spli>ng Only)
70% 60% 50% 40% 30% 20% 10% 0% Thompson and Stamey* (1973)
Fowler (1984)
Lewi McCartney (1984) (1985)
Bratell (1990)
Hugosson* (1990)
Gault (1995)
Figure 2 – Struvite Stone Culture Results
* Studies included both intrarenal and extrarenal stones
25% 20%
Table 1 – Demographics of En*re Sample and Comparison of Struvite and Non-‐Struvite Formers All
Struvite
15% 10% 5% 0%
Table 4 – Profiles of Subjects with Sterile Struvite Stones Table 2 – Culture Results for En*re Sample and Comparison of Struvite and Non-‐Struvite Stones Stone Cx -‐ All organisms no. pos (%) Stone Cx – US Only no. pos (%) Preop Urine Cx – All organisms no. pos (%) Preop Urine Cx – US Only no. pos (%) Prev Urine Cx -‐ All organisms no. pos (%) Prev Urine Cx – US Only no. pos (%)
Struvite Non-‐Struvite p-‐value 28 (70) 95 (24) < 0.001 12 (30)
40 (10)
< 0.001
23 (56)
85 (22)
< 0.001
13 (32)
38 (10)
< 0.001
24 (86) 15 (54)
-‐-‐-‐ -‐-‐-‐
-‐-‐-‐ -‐-‐-‐
Previous Previous UCx Pt. # Recurrent UTI Risk Factors ABX (Sex) UTI Neurogenic bladder N P. aeruginosa 3 (F) Y
Preop UCx
Intraop UCx
No growth
No growth
Retroperitoneal mass N
E. coli
No growth
No growth
-‐-‐-‐
No growth
No growth
No growth
Calyceal Diver-culum Y
K. pneumoniae
K. pneumoniae
No growth
Neurogenic bladder
Y
P. mirabilis
No growth
No growth
-‐-‐-‐
Y
No growth
No growth
No growth
DM
Y
E. coli
E. coli
No growth
DM
N
No growth
No growth
No growth
Neurogenic bladder
Y
S. agalac6ae
No growth
No growth
Bifid collec-ng system -‐-‐-‐
Y
-‐-‐-‐
No growth
No growth
Y
S. saprophy6cus
No growth
No growth
Pregnancy
Y
P. mirabilis
No growth
No growth
10(F) 12(M) 14 (F) 15 (F) 17 (F) 18 (F)
Y Y Y N Y Y
22 (F) N 28 (F) Y 30 (F) Y 31 (F) Y 36 (F) Y
Y
• While culture results, demographic data and clinical history suggest a significant associa-on between struvite stones and infec-on, urea-‐ spli>ng organisms could not be iden-fied in associa-on with all struvite stones in this series • The finding of sterile struvite stones suggests possible stone steriliza-on, especially in the context of extensive preopera-ve an-bio-c exposure • The presence of tradi-onally non-‐urea-‐spli>ng organisms on stone culture encourages 1) reevalua-on of their urease-‐producing poten-al, 2) considera-on of a contributory role in struvite forma-on and 3) expansion of an-bio-c coverage for both Enterococcus spp. and E. coli in the management of suspected struvite stones
