Abstract
Introduction
Gram staining is a convenient method for bacterial estimation. Urine culture is typically
used to diagnose urinary tract infections. Therefore, urine culture is also performed
on Gram stain-negative urine specimens. However, the frequency of uropathogen identification
in these samples remains unclear.
Methods
From 2016 to 2019, we retrospectively compared the results of Gram staining and urine
culture tests on midstream urine specimens submitted for the diagnosis of urinary
tract infections to confirm the significance of urine culture on Gram stain-negative
specimens. Analysis was performed according to the patients’ sex and age, and the
frequency of uropathogen identification in the culture was examined.
Results
A total of 1763 urine specimens (women, 931; men, 832) were collected. Of these, 448
(25.4%) were not positive on Gram staining but were positive on culture. In specimens
without bacteria on Gram staining, the frequencies of specimens with uropathogens
detected on culture were 20.8% (22/106) in women aged <50 years, 21.4% (71/332) in
women aged ≥50 years, 2.0% (2/99) in men aged <50 years, and 7.8% (39/499) in men
aged ≥50 years.
Conclusions
In men aged <50 years, the frequency of uropathogenic bacteria identification by urine
culture was low in Gram stain-negative specimens. Therefore, urine cultures may be
excluded from this group. In contrast, in women, a small number of Gram stain-negative
specimens showed significant culture results for the diagnosis of urinary tract infection.
Therefore, urine culture should not be omitted in women without careful consideration.
Keywords
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References
- New and developing diagnostic technologies for urinary tract infections.Nat Rev Urol. 2017; 14: 296-310
- Laboratory diagnosis of urinary tract infections in adult patients.Clin Infect Dis. 2004; 38: 1150-1158
- Point-counterpoint: reflex cultures reduce laboratory workload and improve antimicrobial stewardship in patients suspected of having urinary tract infections.J Clin Microbiol. 2016; 54: 254-258
- JAID/JSC guidelines for clinical management of infectious disease 2015 - urinary tract infection/male genital infection.J Infect Chemother. 2017; 23: 733-751
- Cumitech 2c: laboratory diagnosis of urinary tract infections.ASM Press, Washington, DC2009
- Japanese guideline for clinical research of antimicrobial agents on urogenital infections: second edition.J Infect Chemother. 2016; 22: 651-661
- Diagnosis of coliform infection in acutely dysuric women.N Engl J Med. 1982; 307: 463-468
- Voided midstream urine culture and acute cystitis in premenopausal women.N Engl J Med. 2013; 369: 1883-1891
- Age of menopause in Japanese women: trends and recent changes.Maturitas. 1990; 12: 43-49
- Age at menopause and mortality in Japan: the Jichi medical school cohort study.J Epidemiol. 2006; 16: 161-166
- Outline of JUA clinical guidelines for benign prostatic hyperplasia.Int J Urol. 2011; 18: 741-756
- Advances and challenges in the diagnosis and treatment of urinary tract infections: the need for diagnostic stewardship.Curr Infect Dis Rep. 2019; 21: 11
- Rapid bioluminescence method for bacteriuria screening.J Clin Microbiol. 1989; 27: 716-720
- Evaluation of dipstrips, direct Gram stain and pyuria as screening tests for the detection of bacteriuria.J Pakistan Med Assoc. 1996; 46: 38-41
- Simplified technique for detection of significant bacteriuria by microscopic examination of urine.J Clin Microbiol. 1998; 36: 820-823
- Performance of flow cytometry to screen urine for bacteria and white blood cells prior to urine culture.Clin Biochem. 2013; 46: 810-813
- Gram-stain plus MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) for a rapid diagnosis of urinary tract infection.PLoS One. 2014; 9e86915
- Evaluation of the cytocentrifuge Gram stain as a screening test for bacteriuria in specimens from specific patient populations.Am J Clin Pathol. 1997; 108: 515-524
- Concentrated Gram stain smears prepared with a cytospin centrifuge.J Clin Microbiol. 1982; 16: 1052-1056
- Practices of clinical microbiology laboratories in reporting voided urine culture results.Clin Microbiol Infect. 2018; 24: 669-670
- Does Escherichia coli have pathogenic potential at a low level of bacteriuria in recurrent, uncomplicated urinary tract infection?.Int J Antimicrob Agents. 2020; 56105983
- Epidemiology and natural history of benign prostatic hyperplasia.Int J Urol. 1997; 4: 233-246
- Gram-positive uropathogens, polymicrobial urinary tract infection, and the emerging microbiota of the urinary tract.Microbiol Spectr. 2016; 4https://doi.org/10.1128/microbiolspec.UTI-0012-2012
- Point-of-care urine Gram stain led to narrower-spectrum antimicrobial selection for febrile urinary tract infection in adolescents and adults.BMC Infect Dis. 2022; 22: 198
- Do patients who complain of lower urinary tract symptoms frequently have clinically significant pyuria?.J Infect Chemother. 2015; 21: 31-33
- Guidelines for infection control in the urological field, including urinary tract management: rev.Int J Urol. 2021; 28 (second ed.): 1198-1211
Article info
Publication history
Published online: May 03, 2023
Accepted:
April 18,
2023
Received in revised form:
April 4,
2023
Received:
February 21,
2023
Publication stage
In Press Corrected ProofIdentification
Copyright
© 2023 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
