Inducible Clindamyc in Resistance among Methicillin-Resistant <i>Staphylococcus aureus</i> Isolates in a Tertiary Care Hospital: A Phenotypic Detection
Keywords:
ICR (Inducible Clindamycin Resistance), MRSA, MSSA, Vancomycin Screen AgarAbstract
Background: Staphylococcus aureus is one of the most commonly isolated pathogens from various clinical specimens, and it is implicated in both community-acquired and healthcare-associated infections. It is an important member of the notorious ESKAPE group of pathogens. They are named so because they are infamous for their abilities to escape antimicrobial action by adopting various resistance mechanisms. Being the 2nd most commonly isolated bacterial species among them, S. aureus has its fair share of resistance mechanisms. Methicillin resistance is increasingly being reported worldwide, and S. aureus resistant to more than 2 classes of antibiotics is also rising alarmingly. Objective: To understand the susceptibility and resistance profile of S. aureus isolates with special focus on MRSA isolates and to identify inducible clindamycin resistance among them using CLSI-approved phenotypic detection methods. Methods: This was a descriptive cross-sectional study conducted in the Department of Microbiology, Coimbatore Medical College and Hospital, Coimbatore, Tamil Nadu, India, between December 2024 and February 2025. The study included 170 S. aureus isolates. Results: At the end of this study, the majority of S. aureus isolations were from pus samples at 55% followed by blood samples at 30%. Antimicrobial susceptibility testing of 170 isolates showed MRSA in 35.9% isolates. Resistance rates of 89% to ampicillin, 70% to gentamicin, 61% to ciprofloxacin and 53% to erythromycin were recorded, while the susceptibility rates were 100% to linezolid, 91% to doxycycline, 75% to cotrimoxazole, 62% to clindamycin. Inducible clindamycin resistance-ICR was detected by the D-test among 16% of isolates. 100% susceptibility towards vancomycin was established by performing a vancomycin screen agar. Conclusion: The results highlighted that MDR S. aureus were more common among MRSA isolates, and the need to look out for both constitutive and inducible clindamycin resistance, as clindamycin is favoured by many clinicians to counteract the toxins of S. aureus.
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References
1. Indian Council of Medical Research. Annual report 2023: Antimicrobial resistance research and surveillance network (AMRSN). New Delhi: ICMR; 2024.
2. World Health Organization. WHO bacterial priority pathogens list, 2024: Bacterial pathogens of public health importance to guide research, development and strategies to prevent and control antimicrobial resistance. Geneva: World Health Organization; 2024.
3. Indian Council of Medical Research. Annual report 2021: Antimicrobial Resistance Research and Surveillance Network (AMRSN). New Delhi: ICMR; 2022.
4. Indian Council of Medical Research. Annual report 2022: Antimicrobial Resistance Research and Surveillance Network (AMRSN). New Delhi: ICMR; 2023.
5. Apurba AMS, Sastry AS, Priyadarshi K, Deepashree R. Essentials of antimicrobial stewardship. 1st ed., New Delhi: Jaypee Brothers Medical Publishers; 2023.
6. Loscalzo JH, Kasper DL, Longo DL, Fauci AS, Hauser SL, Jameson JL (ed). Harrison’s principles of internal medicine. 21st ed. New York: McGraw Hill Education; 2022.
7. Bobenchik AM, Hindler JA, Giltner CL, Saeki S, Humphries RM. Performance of Vitek 2 for antimicrobial susceptibility testing of Staphylococcus spp. and Enterococcus spp. J Clin Microbiol. 2014; 52(2):392-397. https://doi.org/10.1128/JCM.02432-13 PMid:24478467 PMCid:PMC3911353
8. Koneman EW, Allen SD, Janda WM, Schreckenberger PC, Procop GW, Woods GL, et al. Koneman’s colour atlas and textbook of diagnostic microbiology. 7th ed. Philadelphia (PA): Wolters Kluwer Health/Lippincott Williams and Wilkins; 2017.
9. Tripathi KD. Essentials of Medical Pharmacology. 9th ed., New Delhi: Jaypee Brothers Medical Publishers; 2024.
10. Clinical and Laboratory Standards Institute (CLSI). Performance standards for antimicrobial susceptibility testing. 35th ed. CLSI supplement M100. Wayne (PA): CLSI; 2025
11. Nandhana DB, Murali A, Deepthy BJ. Deciphering the distribution of ESKAPE pathogens in various clinical samples and its pattern of antimicrobial resistance: A study from a tertiary care centre in Wayanad, Kerala. Int J Res Med Sci. 2024; 12:3679-3683. https://doi.org/10.18203/2320-6012.ijrms20242925
12. Joshi S, Ray P, Manchanda V, Bajaj J, Chitnis DS, Gautam V, et al. Methicillin resistant Staphylococcus aureus (MRSA) in India: Prevalence and susceptibility pattern. Indian J Med Res. 2013 Feb;137(2):363–9.
13. Wattal C, Goel N, Oberoi JK, Raveendran R, Datta S, Prasad KJ. Surveillance of multidrug resistant organisms in tertiary care hospital in Delhi, India. J Assoc Physicians India. 2010; 58(Suppl:):32-36.
14. Jindal N, Malhotra R, Grover P, Singh S, Bansal R, Kaur S. Methicillin resistant Staphylococcus aureus (MRSA) in Malwa region of Punjab (North-West India). Indian J Med Res. 2016; 143(3):371-372. https://doi.org/10.4103/0971-5916.182630 PMid:27241653 PMCid:PMC4892086
15. Eshwara VK, Munim F, Tellapragada C, Kamath A, Varma M, Lewis LE, et al. Staphylococcus aureus bacteremia in an Indian tertiary care hospital: Observational study on clinical epidemiology, resistance characteristics, and carriage of the Panton-Valentine leukocidin gene. Int J Infect Dis. 2013; 17(11):e1051-e1055. https://doi.org/10.1016/j.ijid.2013.06.002 PMid:23891294
16. Pai V, Rao VI, Rao SP. Prevalence and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus [MRSA] isolates at a Tertiary Care Hospital in Mangalore, South India. J Lab Physicians. 2010 ;2(2):82-84. https://doi.org/10.4103/09742727.72155 PMid:21346902 PMCid:PMC3040090
17. Khan MF. Brief history of Staphylococcus aureus: A focus to antibiotic resistance. EC Microbiology. 2017; 5(2):36-39.
18. Kaur H, Purwar S, Saini A, Kaur H. Status of methicillin resistant Staphylococcus aureus infections and evaluation of PVL producing strains in Belgaum, South India. J Krishna Inst Med Sci Univ. 2017; 1:43-51.
19. Arora S, Devi P, Arora U, Devi B. Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary care hospital in Northern India. J Lab Physicians. 2010; 2(2):78-81. https://doi.org/10.4103/0974-2727.72154 PMid:21346901 PMCid:PMC3040078
20. Tersing, RS, Neoh KM, Eisinger SW, Dam LM, Tekle T, Carroll KC. Comparison of commercial antimicrobial susceptibility test methods for testing of Staphylococcus aureus and Enterococci against vancomycin, daptomycin, and linezolid. J Clin Microbiol. 2014; 52(6):2216-2222. https://doi.org/10.1128/JCM.0095714 PMid:24719445 PMCid:PMC4042782
21. Nirwan P, Srivastava P, Abbas A. Prevalence and antibiogram of hospital acquired-methicillin resistant Staphylococcus aureus and community acquiredmethicillin resistant Staphylococcus aureus at a tertiary care hospital National Institute of Medical Sciences. Community Acquir Infect. 2015; 2(1):13. https://doi.org/10.4103/2225-6482.153857
22. Kali A, Stephen S, Umadevi S, Kumar S, Joseph NM, Srirangaraj S. Changing trends in resistance pattern of methicillin resistant Staphylococcus aureus. J Clin Diagn Res. 2013; 7(9):1979-1982. https://doi.org/10.7860/JCDR/2013/6142.3377 PMid:24179914 PMCid:PMC3809653
23. Deotale V, Mendiratta DK, Raut U, Narang P. Inducible clindamycin resistance in Staphylococcus aureus isolated from clinical samples. Indian J Med Microbiol. 2010; 28(2):124-126. https://doi.org/10.4103/0255-0857.62488 PMid:20404457
24. Nikam AP, Bhise PR, Deshmukh MM. Phenotypic detection of inducible clindamycin resistance among Staphylococcus aureus isolates. Int J Res Med Sci. 2017 ;5(2):543-547. https://doi.org/10.18203/2320-6012.ijrms20170148
25. Panwala T, Gandhi P, Jethwa D. Inducible clindamycin resistance and MRSA amongst Staphylococcus aureus isolates: A phenotypic detection. IP Int J Med Microbiol Trop Dis. 2025; 6(4):222-226. https://doi.org/10.18231/j.ijmmtd.2020.050
