Direct disk testing versus isolation and antimicrobial susceptibility testing of urine from urinary tract infection
Abstract
Background and Objectives: Urinary tract infections are common infections that can be caused by many bacterial pathogens. The susceptibility of such pathogens to antimicrobial agents is identified by different methods including disk diffusion test, direct sensitivity testing and determination minimum inhibitory concentration. The present study was conducted to isolate and identify bacteria cultured from urine samples and compare the results of direct sensitivity test (DST) against Kirby-Bauer’s disk diffusion antimicrobial sensitivity (AST) with respect to reliability, time and cost.
Materials and Methods: Midstream urine samples were inoculated on blood and MacConkey agar plates; growth was evaluated after colony counting. We identified isolates based on their cultural and biochemical properties, and Vitek® 2 system.Both DST and AST were performed on Mueller-Hinton agar using 10 antimicrobial agents. Error rate was calculated between the DST and AST as the proportion of comparisons between DST and AST test results. The comparisons represented as "very major error", "major error", or "minor error" and "agreement" (i.e, no error).
Results: We tested 373 urine samples, of them 257 (68.9%) were from females and 116 (31.1%) from males. Primary cultivation detected growth (>105 cfu/mL) from 206 (55.23%) samples; Gram-negative isolates were the most common isolates; these included Escherichia coli (111, 51.87%), and Klebsiella pneumoniae (19, 8.88%), while Staphylococcus aureus (14, 6.54%) was the main Gram-positive isolate. From the 1940 individual comparisons of DST and AST of single (pure) bacterial isolates, 12 comparisons (0.6%) represented very major errors, 9 (0.5%) major errors, 36 (1.8%) minor errors, and 1883 comparisons (97.1%) were in agreement.
Conclusion: E. coli was the most common isolate. Cefixime and cefpodoxime were found to be the most ineffective antimicrobial agents, while meropenem and nitrofurantoin were the most effective agents against all isolated urinary pathogens. DST and AST almost give the same results in pure cultures, and direct antimicrobial susceptibility for urine specimens can safely replace standard antimicrobial susceptibility in urinary tract infection.
Stamm WE, Norrby SR. Urinary tract infections: disease panorama and challenges. J Infect Dis 2001;183 Suppl 1:S1-4.
Foxman B. Urinary tract infection syndromes: occurrence, recurrence, bacteriology, risk factors, and disease burden. Infect Dis Clin North Am 2014;28:1-13.
Hooton TM, Bradley SF, Cardenas DD, Colgan R, Geerlings SE, Rice JC, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 international clinical practice guidelines from the infectious diseases society of America. Clin Infect Dis 2010;50:625-663.
Flores-Mireles AL, Walker JN, Caparon M, Hultgren SJ. Urinary tract infections: epidemiology, mechanisms of infection and treatment options. Nat Rev Microbiol 2015;13:269-284.
Pietrucha-Dilanchian P, Hooton TM. Diagnosis, treatment, and prevention of urinary tract infection. Microbiol Spectr 2016;4(6). doi: 10.1128/microbiolspec.UTI-0021-2015.
Hiraoka M, Hida Y, Hori C, Tsuchida S, Kuroda M, Sudo M. Urine microscopy on a counting chamber for diagnosis of urinary infection. Acta Paediatr Jpn 1995;37:27-30.
Carroll KC, Hale DC, Von Boerum DH, Reich GC, Hamilton LT, Matsen JM. Laboratory evaluation of urinary tract infections in an ambulatory clinic. Am J Clin Pathol 1994;101:100-103.
Wilson ML, Gaido L. Laboratory diagnosis of urinary tract infections in adult patients. Clin Infect Dis 2004;38:1150-1158.
Stark RP, Maki DG. Bacteriuria in the catheterized patient. What quantitative level of bacteriuria is relevant? N Engl J Med 1984;311:560-564.
Bauer A, Kirby W, Sherris J, Turck M. Antibiotic susceptibility testing by a standardized single disk method. Am J Clin Pathol 1966;45:493-496.
Collee JG, Miles RS, Watt B. Tests for the identiication of bacteria. In: Collee JG, A.G. Fraser AG, Marmion BP, SimmonsA, editors. In Mackie and Mc Artney Practical Medical Microbiology London, ChurchillLivingstone, UK: 1996. p. 433.
Coorevits L, Boelens J, Claeys G. Direct susceptibility testing by disk diffusion on clinical samples: a rapid and accurate tool for antibiotic stewardship. Eur J Clin Microbiol Infect Dis 2015;34:1207-1212.
Breteler KB, Rentenaar RJ, Verkaart G, Sturm PD. Performance and clinical significance of direct antimicrobial susceptibility testing on urine from hospitalized patients. Scand J Infect Dis 2011;43:771-776.
CLSI. Performance standards for antimicrobial disk susceptibility tests: twenty third informational supplement. Wayne, PA: clinical and laboratory standards institute 2013.
Johnson JR, Tiu FS, Stamm WE. Direct antimicrobial susceptibility testing for acute urinary tract infections in women. J Clin Microbiol 1995;33:2316-2323.
Abejew AA, Denboba AA, Mekonnen AG. Prevalence and antibiotic resistance pattern of urinary tract bacterial infections in Dessie area, North-East Ethiopia. BMC Res Notes 2014;7:687.
Gupta S, Kapur S, Padmavathi DV. Comparative prevalence of antimicrobial resistance in community-acquired Urinary Tract Infection Cases from Representative states of northern and southern India. J Clin Diagn Res 2014 Sep;8(9):DC09-12.
Oladeinde BH, Omoregie R, Olley M, Anunibe JA. Urinary tract infection in a rural community of Nigeria. N Am J Med Sci 2011;3:75-77.
Magliano E, Grazioli V, Deflorio L, Leuci AI, Mattina R, Romano P, et al. Gender and age-dependent etiology of community-acquired urinary tract infections. ScientificWorldJournal 2012;2012:349597.
Anthony A. Nash, Robert G. Dalziel, J. Ross Fitzgerald. MIMS’ pathogenesis of infectious diseases 6 ed. Great Britain: Elsevier; 2015. 356 p.
Dimitrov TS, Udo EE, Emara M, Awni F, Passadilla R. Etiology and antibiotic susceptibility patterns of community-acquired urinary tract infections in a Kuwait hospital. Med Princ Pract 2004;13:334-339.
Raka L, Mulliqi-Osmani G, Berisha L, Begolli L, Omeragiq S, Parsons L, et al. Etiology and susceptibility of urinary tract isolates in Kosova. Int J Antimicrob Agents 2004;23 Suppl 1:S2-5.
Hamawandi AM, Omer SA, Tayib TH, Mustafa MK. Antibacterial susceptibility in urinary tract infection among children in Sulaimani. JSMC 2015;5:1-6.
Pallett A, Hand K. Complicated urinary tract infections: practical solutions for the treatment of multiresistant gram-negative bacteria. J Antimicrob Chemother 2010;65 Suppl 3:iii25-33.
Dibua UME, Onyemerela IS, Nweze EI. Frequency, urinalysis and susceptibility profile of pathogens causing urinary tract infections in Enugu State, southeast Nigeria. Rev Inst Med Trop Sao Paulo 2014;56:55-59.
Shariff V A AR, Shenoy M S, Yadav T, M R. The antibiotic susceptibility patterns of uropathogenic Escherichia coli, with special reference to the fluoroquinolones. J Clin Diagn Res 2013;7:1027-1030.
Odongo CO, Anywar DA, Luryamamoi K, Odongo P. Antibiograms from community-acquired uropathogens in Gulu, northern Uganda--a cross-sectional study. BMC Infect Dis 2013;13:193.
Namratha W Nandihal. Profile of urinary tract infection and quinolone resistance among Escherichia coli and Klebsiella species isolates. IJCMAS 2015;4: 749-756.
Kallenius G, Dornbusch K, Hallander HO, Jakobsson K. Comparison of direct and standardized antibiotic susceptibility testing in bacteriuria. Chemotherapy 1981;27:99-105.
Oakes AR, Badger R, Grove DI. Comparison of direct and standardized testing of infected urine for antimicrobial susceptibilities by disk diffusion. J Clin Microbiol 1994;32:40-45.
| Files | ||
| Issue | Vol 10 No 1 (2018) | |
| Section | Original Article(s) | |
| Keywords | ||
| Urinary tract infection Antimicrobial Direct sensitivity testing | ||
| Rights and permissions | |
|
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
