ASSESSMENT OF VANCOMYCIN MIC CREEP PHENOMENON IN METHICILIN-RESISTANT STAPHYLOCOCCUS AUREUS ISOLATES IN A TERTIARY CARE HOSPITAL OF SURAT.
Main Article Content
Keywords
Vancomycin, Methicillin-resistant staphylococcus aureus (MRSA), Creep, minimum inhibitory concentration (MIC).
Abstract
The "Methicillin-resistant Staphylococcus aureus (MRSA) is regarded as a major public health concern worldwide, as it is associated with severe infections, elevated mortality rates, and limited treatment options, particularly in healthcare settings."Vancomycin remains the primary therapeutic agent for MRSA infections; however, increasing concern has arisen regarding vancomycin treatment failures despite isolates falling within the susceptible range. This phenomenon, termed “MIC creep,” refers to the gradual rise in vancomycin MICs over time and is associated with poorer clinical outcomes.
Methods: The current analysis was designed as cross sectional, retrospective, observational
study over a three-year period, from January 2021 to December 2023. A total of 881 non-duplicate Staphylococcus aureus isolates resistant to methicillin (MRSA) were recovered from various clinical specimens, including blood, pus, wound swabs, tissue, and urine. Following the clinical and laboratory standards institute (CLSI) 2023 guidelines bacterial determination and antimicrobial susceptibility testing was performed. By employing the E-Test method vancomycin (MICs) were evaluated. Statistical analysis was done by using the annual trends in MIC values.
Results: Of the 881 MRSA isolates, the majority were from females (64.02%) with a mean age of 52.3 years. Wound swabs (51.31%) and surgical wards (35.30%) were the predominant sources. A gradual increase in vancomycin MIC values was observed from 2021 to 2023. Isolates with MIC ≤0.5 µg/mL decreased from 72.82% to 64.17%, while those with MIC ≥1.5 µg/mL increased from 6.16% to 7.82%. The arithmetic and geometric mean MICs rose significantly (p < 0.0001), confirming the presence of MIC creep.
Conclusion: The study demonstrates a statistically significant vancomycin MIC creep among MRSA isolates, underscoring the need for continued antimicrobial surveillance and judicious vancomycin use to prevent therapeutic failure.
References
2. Islam T, Kubra K, Hassan Chowdhury MM. Prevalence of Methicillin-Resistant Staphylococcus aureus in Hospitals in Chitta gong, Bangladesh: A Threat of Nosocomial Infection. J Microsc Ultrastruct. 2018;6(4):188-191. doi: 10.4103/JMAU.JMAU_33_18
3. Hyun I-K, Park PJ, Park D, Choi SB, Han HJ, Song T-J, et al. Methicillin-resistant Staphylococcus aureus screening is important for surgeons. Ann Hepato-Biliary-Pancreatic Surg. 2019;23(3):265-273. doi: 10.14701/ahbps.2019.23.3.265
4. Anitha TK, Rao MR, Shankaregowda R, Mahale RP, Sowmya GS, Chitharagi VB. Evaluation of Vancomycin Minimum Inhibitory Concentration in the clinical isolates of Methicillin Resistant Staphylococcus aureus (MRSA). J Pure Appl Microbiol. 2019;13(3):1797-1801. doi: 10.22207/JPAM.13.3.56
5. Wilcox M, Al-Obeid S, Gales A, Kozlov R, Martinez-Orozco JA, Rossi F, et al. Reporting elevated vancomycin minimum inhibitory concentration in methicillin-resistant Staphylococcus aureus: Consensus by an International Working Group. Future Microbiol. 2019;14(4):345-352. doi: 10.2217/fmb-2018-0346
6. Hidayat LK, Hsu DI, Quist R, Shriner KA, Wong-Beringer A. High-dose van comycin therapy for methicillin-resistant Staphylococcus aureus infections: efficacy and toxicity. Arch Intern Med 2006;166(October (19)):2138–44.
7. Moise-Broder PA, Sakoulas G, Eliopoulos GM, Schentag JJ, Forrest A, Moellering Jr RC. Accessory gene regulator group II polymorphism in methicillin-resistant Staphylococcus aureus is predictive of failure of vancomycin therapy. Clin Infect Dis 2004;38(June (12)):1700–5.
8. Chang CN, Lo WT, Chan MC, Yu CM, Wang CC. An investigation of vancomycin minimum inhibitory concentration creep among methicillin-resistant Staphylococcus aureus strains isolated from pediatric patients and healthy children in Northern Taiwan. J Microbiol Immunol Infect. 2017;50(3):362–369. doi: 10.1016/j.jmii.2015.05.013. doi:10.1016/j.jmii.2015.05. 013. [DOI].
9. Sakoulas G, Moise-Broder PA, Schentag J, Forrest A, Moellering RCJ, Eliopoulos GM. Relationship of MIC and bactericidal activity to efficacy of vancomycin for treatment of methicillin-resistant Staphylococcus aureus bacteremia. J Clin Microbiol 2004;42(June (6)):2398–402.
10. Alex Soriano, Francesc Marco, José A. Martínez, Elena Pisos, Manel Almela, Veselka P. Dimova, Dolores Alamo, Mar Ortega, Josefina Lopez, Josep Mensa, Influence of Vancomycin Minimum Inhibitory Concentration on the Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia, Clinical Infectious Diseases, Volume 46, Issue 2, 15 January 2008, Pages 193–200, https://doi.org/10.1086/524667.
11. Ahmad N, Nawi S, Rajasekaran G, Maning N, Aziz MN, Husin A, et al. Increased vancomycin minimum inhibitory concentration among Staphylococcus aureus isolates in Malaysia. J Med Microbiol. 2010;59(12):1530–1532. doi: 10.1099/jmm.0.022079-0. doi:10.1099/jmm.0.02207 9-0. [DOI
12. Ejaz H. Determination of bacterial profile and spectrum of antimicrobial drug resistance in pediatric wound infections. J Pure Appl Microbiol. 2019;13(4):2097–2104. doi:10.22207/ JPAM.13.4.21.
13. Kshetry AO, Pant ND, Bhandari R, Khatri S, Shrestha KL, Upadhaya SK, et al. Minimum inhibitory concentration of vancomycin to methicillin resistant Staphylococcus aureus isolated from different clinical samples at a tertiary care hospital in Nepal. Antimicrob Resist Infect Control. 2016;5(1):4–9. doi: 10.1186/s13756-016-0126-3. doi:10.1186/s13756-016-0126-3. [DOI
14. Arshad F, Saleem S, Jahan S, Tahir R. Assessment of Vancomycin MIC Creep Phenomenon in Methicillin-Resistant Staphylococcus aureus isolates in a Tertiary Care Hospital of Lahore. Pak J Med Sci. 2020 Nov-Dec;36(7):1505-1510. doi: 10.12669/pjms.36.7.3273. PMID: 33235565; PMCID: PMC7674903.
15. Sader HS, Fey PD, Fish DN, Limaye AP, Pankey G, Rahal J, et al. Evaluation of vancomycin and daptomycin potency trends (MIC creep) against methicillin-resistant Staphylococcus aureus isolates collected in nine U.S. Medical Centers from 2002 to 2006. Antimicrob Agents Chemother. 2009;53(10):4127–4132. doi: 10.1128/AAC.00616-09. doi:10.1128/AAC.00616-09. [DOI].
16. Aljohani S, Layqah L, Masuadi E, Al Alwan B, Baharoon W, Gramish J, Baharoon S. Occurrence of vancomycin MIC creep in methicillin resistant isolates in Saudi Arabia. Journal of Infection and Public Health. 2020 Oct 1;13(10):1576-9.
17. Cheema KH, Javed I, Mushtaq S. Anwar MS. Heteroresistant Vancomycin Intermediate Staphylococcus aureus in a tertiary care hosptital. Biomedica. 2017;33(3):192-196.
18. Ejaz H. Determination of bacterial profile and spectrum of antimicrobial drug resistance in pediatric wound infections. J Pure Appl Microbiol. 2019;13(4):2097-2104. doi: 10.22207/ JPAM.13.4.21
19. Soriano A, Marco F, Martinez J, Pisos E, Almela M, Dimova VP, et al. Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia. Clin Infect Dis. 2008;46(2):193–200. doi: 10.1086/524667. doi:10.1086/524667. [DOI].
20. Sakoulas G, Moise-Broder PA, Schentag J, Forrest A, Moellering RC, Eliopoulos GM. Relationship of MIC and bactericidal activity to efficacy of vancomycin for treatment of methicillin-resistant Staphylococcus aureus bacteremia. J Clin Microbiol. 2004;42(6):2398–2402. doi: 10.1128/JCM.42.6.2398-2402.2004. doi:10.1128/JCM.42.6.2398-2402.2004. [DOI]
Article Sidebar
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
All articles published in JPTCP are licensed under Copyright Creative Commons Attribution-NonCommercial 4.0 International License.
Dr. Bidisa Pal
3rd Year PG Resident at Department of Microbiology, Government Medical College, Surat, Gujarat, India
Dr. Summaiya Mullan
Professor & Head at Department of Microbiology, Government Medical College, Surat, Gujarat, India.