EVALUATION OF CHROMAGARTM ORIENTATION CHROMOGENIC MEDIUM FOR ISOLATION AND DIFFERENTIATION OF PATHOGENIC URINARY TRACT MICROORGANISMS

Aim. To evaluate CHROMagar™ Orientation Chromogenic Medium for isolation and differentiation of pathogenic urinary tract microorganisms.

Materials and methods. A prospective study was conducted, which included 147 consecutive urine samples from patients with clinically suspected UTIs of Karaganda city (Republic of Kazakhstan) in 2019. The presumptive microorganisms’ identification was carried out at CHROMagar™ Orientation in accordance with morphology, colony color on the characteristics recommended by the manufacturer. The final identification of isolates to species was performed by matrix-associated laser desorption/ionization – time-of-flight mass spectrometry (MALDI-TOF MS) using the Microflex LT system and the MALDI Biotyper Compass v.4.1.80 software (Bruker Daltonics, Germany). The recommended values of Score ≥2.0 were used as a criterion for reliable species identification.

Results and discussion. 55 (37.4%) of 147 urine cultures gave a positive growth of bacteria, 86 (58.5%) did not give a growth, 6 samples were regarded as contaminated material. Comparative results of using CHROMagar™ Orientation for identification of the claimed microorganisms reached 100% sensitivity and specificity compared to mass-spectrometry. Excellent species identification was for E. coli – colonies were stained in dark pink, but there are some limitations for the rest microorganisms – Klebsiella, Enterobacter, Citrobacter, Serratia, respectively, in such cases, further species identification with additional tests is necessary.

Conclusions. The results of the study showed that the chromogenic environment of CHROMagar™ Orientation can be used to isolate and differentiate urinary tract microorganisms. This is a reliable identification of relevant uropathogens, cultures differentiation, saving time and research costs.

1. Palagin I.S., Suhorukova M.V., Dehnich A.V. Antibiotikorezistentnost' vozbuditelej vnebol'nichnyh infekcij mochevyh putej v Rossii: rezul'taty mnogocentrovogo issledovanija «DARMIS-2018». Klinicheskaja mikrobiologija i antimikrobnaja himioterapija. 2019; 21 (2): 134 -146.

2. Shipicyna E.V., Husnutdinova T.A., Savicheva A.M. Infekcii mochevyvodjashhih putej v akusherstve i ginekologii. Zhurnal akusherstva i zhenskih boleznej. 2015; 6: 91-104.

3. Prasad M., Shetty S.K., Nair B.G. A novel and improved selective media for the isolation and enumeration of Klebsiella species. Appl. Microbiol. Biotechnol. 2022; 106 (24): 8273-8284.

4. Shah K.J., Cherabuddi K., Shultz J., Borgert S., Ramphal R., Klinker K.P. Ampicillin for the treatment of complicated urinary tract infections caused by vancomycin-resistant Enterococcus spp (VRE): a single-center university hospital experience. Int. J. Antimicrob Agents. 2018; 51 (1): 57-61.

5. Akter L., Haque R., Salam M.A.Comparative evaluation of chromogenic agar medium and conventional culture system for isolation and presumptive identification of uropathogens. J. Med. Sci. 2014; 30 (5): 1033-1041.

6. Skulnick M., Mitchell B., Mazzulli T. Cost Effectiveness of BBL™ CHROMagar™ Orientation Medium for Routine Urine Cultures. American Society for Microbiology. 2004; 6: 323-329.

7. Dickson K., Zhou J., Lehmann C. Lower. Lower Urinary Tract Inflammation and Infection: Key Microbiological and Immunological Aspects. J. Clin. Med. 2024; 13 (2): 315.

8. Mulet B.J.V., Salvador G.C., Tormo P.N. Novel Chromogenic Medium CHROMagarTM Candida Plus for Detection of Candida auris and Other Candida Species from Surveillance and Environmental Samples: A Multicenter Study. J. Fungi. (Basel). 2022; 8 (3): 281.

9. Smit C.C.H., Lambert M., Rogers K. One Health Determinants of Escherichia coli Antimicrobial Resistance in Humans in the Community: An Umbrella Review. Int. J. Mol. Sci. 2023; 24: 17204.

10. Patel R. MALDI-TOF MS for the diagnosis of infectious diseases. Clin. Chem. 2015; 61 (1): 100-111.

11. Desai D.J., Gilbert B., McBride C.A. Paediatric urinary tract infections: Diagnosis and treatment. Aust. Fam. Physician. 2016; 45 (8): 558-563.

12. Perry J.D. A Decade of Development of Chromogenic Culture Media for Clinical Microbiology in an Era of Molecular Diagnostics. Clin. Microbiol. Rev. 2017; 30 (2): 449-479.

13. Robberts F.J.L., Owusu-Ofori A., Oduro G. Rapid, Low-Complexity, Simultaneous Bacterial Group Identification and Antimicrobial Susceptibility Testing Performed Directly on Positive Blood Culture Bottles Using Chromogenic Agar. Am. J. Trop. Med. Hyg. 2022; 107 (6): 1302-1307.

14. Aydin A., Ahmed K., Zaman I. Recurrent urinary tract infections in women. Int. Urogynecol. J. 2015; 26 (6): 795-804.

15. Kodner C.M., Gupton T. Recurrent urinary tract infections in women: diagnosis and management. Am. Fam. Physician. 2010; 82 (6): 638-643.

16. Stefaniuk E.M. The Usefulness of Chromogenic Media for Qualitative and Semi-Quantitative Diagnostic of Urinary Tract Infections. Pol. J. Microbiol. 2018; 67 (2): 213-218.

17. Foroogh N., Rezvan M., Ahmad K., Mahmood S. Structural and functional characterization of the FimH adhesin of uropathogenic Escherichia coli and its novel applications. Microb. Pathog. 2021; 161: 105288.

18. Gupta K., Grigoryan L., Trautner B. Urinary Tract Infection. Ann. Intern. Med. 2017; 167 (7): 2017 Oct 3;167 (7): ITC49-ITC64.

19. Sharmin S., Alamgir F., Begum F. Use of Chromogenic Agar Media for Identification of Uropathogen. Bangladesh J. Med. Microbiol. 2010; 4 (1): 18-23.