TY - JOUR
T1 - Similar neutrophil-driven inflammatory and antibacterial responses in elderly patients with symptomatic and asymptomatic bacteriuria
AU - Yu, Yanbao
AU - Zielinski, Martin D.
AU - Rolfe, Melanie A.
AU - Kuntz, Melissa M.
AU - Nelson, Heidi
AU - Nelson, Karen E.
AU - Pieper, Rembert
N1 - Publisher Copyright:
© 2015, American Society for Microbiology.
PY - 2015
Y1 - 2015
N2 - Differential diagnosis of asymptomatic bacteriuria (ASB) and urinary tract infection (UTI) is based on the presence of diverse symptoms, including fever (>38.5°C), rigors, malaise, lethargy, flank pain, hematuria, suprapubic discomfort, dysuria, and urgent or frequent urination. There is consensus in the medical community that ASB warrants antibiotic treatment only for patients undergoing urological procedures that lead to mucosal bleeding, catheterized individuals whose ASB persists for more than 48 h after catheter removal, and pregnant women. Pyuria is associated with UTI and implicates host immune responses via release of antibacterial effectors and phagocytosis of pathogens by neutrophils. Such responses are not sufficiently described for ASB. Metaproteomic methods were used here to identify the pathogens and evaluate molecular evidence of distinct immune responses in cases of ASB compared to UTI in elderly patients who were hospitalized upon injury. Neutrophil-driven inflammatory responses to invading bacteria were not discernible in most patients diagnosed with ASB compared to those with UTI. In contrast, proteomic urine analysis for trauma patients with no evidence of bacteriuria, including those who suffered mucosal injuries via urethral catheterization, rarely showed evidence of neutrophil infiltration. The same enzymes contributing to the synthesis of leukotrienes LTB4 and LTC4, mediators of inflammation and pain, were found in the UTI and ASB cohorts. These data support the notion that the pathways mediating inflammation and pain in most elderly patients with ASB are not quantitatively different from those seen in most elderly patients with UTI and warrant larger clinical studies to assess whether a common antibiotic treatment strategy for elderly ASB and UTI patients is justified.
AB - Differential diagnosis of asymptomatic bacteriuria (ASB) and urinary tract infection (UTI) is based on the presence of diverse symptoms, including fever (>38.5°C), rigors, malaise, lethargy, flank pain, hematuria, suprapubic discomfort, dysuria, and urgent or frequent urination. There is consensus in the medical community that ASB warrants antibiotic treatment only for patients undergoing urological procedures that lead to mucosal bleeding, catheterized individuals whose ASB persists for more than 48 h after catheter removal, and pregnant women. Pyuria is associated with UTI and implicates host immune responses via release of antibacterial effectors and phagocytosis of pathogens by neutrophils. Such responses are not sufficiently described for ASB. Metaproteomic methods were used here to identify the pathogens and evaluate molecular evidence of distinct immune responses in cases of ASB compared to UTI in elderly patients who were hospitalized upon injury. Neutrophil-driven inflammatory responses to invading bacteria were not discernible in most patients diagnosed with ASB compared to those with UTI. In contrast, proteomic urine analysis for trauma patients with no evidence of bacteriuria, including those who suffered mucosal injuries via urethral catheterization, rarely showed evidence of neutrophil infiltration. The same enzymes contributing to the synthesis of leukotrienes LTB4 and LTC4, mediators of inflammation and pain, were found in the UTI and ASB cohorts. These data support the notion that the pathways mediating inflammation and pain in most elderly patients with ASB are not quantitatively different from those seen in most elderly patients with UTI and warrant larger clinical studies to assess whether a common antibiotic treatment strategy for elderly ASB and UTI patients is justified.
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U2 - 10.1128/IAI.00745-15
DO - 10.1128/IAI.00745-15
M3 - Article
C2 - 26238715
AN - SCOPUS:84944472847
SN - 0019-9567
VL - 83
SP - 4142
EP - 4153
JO - Infection and Immunity
JF - Infection and Immunity
IS - 10
ER -