Isolation, Phenotypic Characterization and speciation of Vancomycin Resistant Enterococci from Clinical Samples
Keywords:
Vancomycin-resistant enterococci, Vancomycin-resistant enterococci, Enterococcus faecalis, Enterococcus faecalis, Enterococcus faecium, Enterococcus faecium, antimicrobial susceptibility, antimicrobial susceptibility, nosocomial infections., nosocomial infections.Abstract
Background:Vancomycin-resistant enterococci (VRE) represent a growing concern in nosocomial infections due to limited treatment options and their intrinsic and acquired antimicrobial resistance. This study focused on the isolation, phenotypic characterization, and speciation of VRE from diverse clinical samples collected at a tertiary care center in Northern India.
Objectives:To identify and differentiate Enterococcus species from clinical specimens, determine their antimicrobial susceptibility patterns, and estimate the prevalence of vancomycin resistance among these isolates.
Methods:A cross-sectional observational study was conducted from June 2023 to September 2024. Enterococci were isolated using conventional culture methods from blood, urine, pus, cerebrospinal fluid, and other body fluids. Biochemical tests and selective media such as bile esculin azide agar and potassium tellurite agar were used for speciation. Antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method according to CLSI M100 standards. Vancomycin resistance was confirmed using vancomycin screen agar.
Results:A total of 259 Enterococcus isolates were recovered; Enterococcus faecalis constituted 65.25% (n=169) and Enterococcus faecium 34.75% (n=90). The isolates predominantly originated from urine (47.8%) and blood (21.6%). Vancomycin resistance was observed in 4.1% of E. faecalis and 3.3% of E. faecium isolates. High resistance rates were noted for erythromycin (64.6%), penicillin (59.8%), and ampicillin (36.7%). Linezolid, teicoplanin, and vancomycin retained high sensitivity (>95%) among isolates.
Conclusion:E. faecalis was the predominant species isolated with a low but notable prevalence of vancomycin resistance. Judicious antibiotic use, early detection, and strict infection control measures are essential to controlling the spread of multidrug-resistant enterococci in healthcare settings
Downloads
References
Sengupta, M., Sarkar, S., SenGupta, M., Ghosh, S., Sarkar, R., & Banerjee, P. (2021). Biofilm Producing Enterococcus Isolates from Vaginal Microbiota. Antibiotics (Basel, Switzerland), 10(9), 1082. https://doi.org/10.3390/antibiotics10091082.
Krawczyk, B., Wityk, P., Gałęcka, M., & Michalik, M. (2021). The Many Faces of Enterococcus spp.-Commensal, Probiotic and Opportunistic Pathogen. Microorganisms, 9(9), 1900. https://doi.org/10.3390/microorganisms9091900.
. Santajit, S., & Indrawattana, N. (2016). Mechanisms of Antimicrobial Resistance in ESKAPE Pathogens. BioMed research international, 2016, 2475067. https://doi.org/10.1155/2016/2475067.
Idris, F.N., & Nadzir, M.M. (2023). Multi-drug resistant ESKAPE pathogens and the uses of plants as their antimicrobial agents. Archives of microbiology, 205(4), 115. https://doi.org/10.1007/s00203-023-03455-6.
Ramos, S., Silva, V., Dapkevicius, M.L.E., Igrejas, G., & Poeta, P. (2020). Enterococci, from Harmless Bacteria to a Pathogen. Microorganisms, 8(8), 1118. https://doi.org/10.3390/microorganisms8081118.
Fiore, E., Van Tyne, D., & Gilmore, M.S. (2019). Pathogenicity of Enterococci. Microbiology spectrum, 7(4), 10.1128/microbiolspec.gpp3-0053-2018. https://doi.org/10.1128/microbiolspec.GPP3-0053-2018.
Agudelo Higuita, N.I. & Huycke, M.M. (2014). Enterococcal Disease, Epidemiology, and Implications for Treatment. 2014. In: Gilmore M.S., Clewell D.B., Ike Y., et al., editors. Enterococci: From Commensals to Leading Causes of Drug Resistant Infection [Internet]. Boston: Massachusetts Eye and Ear Infirmary; 2014-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK190429/
Goel, V., Kumar, D., Kumar, R., Mathur, P., & Singh, S. (2016). Community Acquired Enterococcal Urinary Tract Infections and Antibiotic Resistance Profile in North India. Journal of laboratory physicians, 8(1), 50–54. https://doi.org/10.4103/0974-2727.176237.
9. Khalil, M.A., Alorabi, J.A., Al-Otaibi, L.M., Ali, S.S., & Elsilk, S.E. (2022). Antibiotic Resistance and Biofilm Formation in Enterococcus spp. Isolated from Urinary Tract Infections. Pathogens (Basel, Switzerland), 12(1), 34. https://doi.org/10.3390/pathogens12010034.
Kampmeier, S., Kossow, A., Clausen, L.M., Knaack, D., Ertmer, C., Gottschalk, A., Freise, H., & Mellmann, A. (2018). Hospital acquired vancomycin resistant enterococci in surgical intensive care patients - a prospective longitudinal study. Antimicrobial resistance and infection control, 7, 103. https://doi.org/10.1186/s13756-018-0394-1.
Vidyalakshmi, P., Gopalakrishnan, R., Ramasubramanian, V., Ghafur, K.A., Nambi, P.S., & Thirunarayana, M. (2012). Clinical, epidemiological, and microbiological profile of patients with vancomycin-resistant enterococci from a tertiary care hospital. Journal of global infectious diseases, 4(2), 137–138. https://doi.org/10.4103/0974-777X.96784.
Das, A.K., Dudeja, M., Kohli, S., & Ray, P. (2022). Genotypic characterization of vancomycin-resistant Enterococcus causing urinary tract infection in northern India. The Indian journal of medical research, 155(3&4), 423–431. https://doi.org/10.4103/ijmr.IJMR_2554_19.
Rezvani, J., Nasr, R., T Shamsabadi, F., & Akbari Eidgahi, M.R. (2016). Frequency of VanA, VanB and VanH variants amongst vancomycin-resistant enterococci isolated from patients in central region of Iran. Gastroenterology and hepatology from bed to bench, 9(4), 308–315.
Fang, H., Hedin, G., Telander, B., Li, G., & Nord, C.E. (2007). Emergence of VanD-type vancomycin-resistant Enterococcus faecium in Stockholm, Sweden. Clinical microbiology and infection: the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 13(1), 106–108. https://doi.org/10.1111/j.1469-0691.2006.01569.x.
Beltrametti, F., Consolandi, A., Carrano, L., Bagatin, F., Rossi, R., Leoni, L., Zennaro, E., Selva, E., & Marinelli, F. (2007). Resistance to glycopeptide antibiotics in the teicoplanin producer is mediated by van gene homologue expression directing the synthesis of a modified cell wall peptidoglycan. Antimicrobial agents and chemotherapy, 51(4), 1135–1141. https://doi.org/10.1128/AAC.01071-06.
Manero, A., & Blanch, A.R. (1999). Identification of Enterococcus spp. with a biochemical key. Applied and environmental microbiology, 65(10), 4425–4430. https://doi.org/10.1128/AEM.65.10.4425-4430.1999
Clinical and Laboratory Standards Institute. 2023. Performance standards for antimicrobial susceptibility testing, 33rd ed CLSI supplement M100 Clinical and Laboratory Standards Institute, Wayne, PA.
Smout, E., Palanisamy, N., & Valappil, S. P. (2023). Prevalence of vancomycin-resistant Enterococci in India between 2000 and 2022: a systematic review and meta-analysis. Antimicrobial resistance and infection control, 12(1), 79. https://doi.org/10.1186/s13756-023-01287-z
1Phukan, C., Lahkar, M., Ranotkar, S., & Saikia, K. K. (2016). Emergence of vanA gene among vancomycin-resistant enterococci in a tertiary care hospital of North - East India. The Indian journal of medical research, 143(3), 357–361. https://doi.org/10.4103/0971-5916.182627
Sivaradjy, M., Gunalan, A., Priyadarshi, K., Madigubba, H., Rajshekar, D., & Sastry, A. S. (2021). Increasing Trend of Vancomycin-resistant Enterococci Bacteremia in a Tertiary Care Hospital of South India: A Three-year Prospective Study. Indian journal of critical care medicine : peer-reviewed, official publication of Indian Society of Critical Care Medicine, 25(8), 881–885. https://doi.org/10.5005/jp-journals-10071-23916
Purohit, G., Gaind, R., Dawar, R., Verma, P. K., Aggarwal, K. C., Sardana, R., & Deb, M. (2017). Characterization of Vancomycin Resistant Enterococci in Hospitalized Patients and Role of Gut Colonization. Journal of clinical and diagnostic research : JCDR, 11(9), DC01–DC05. https://doi.org/10.7860/JCDR/2017/25988.10548
Gold H. S. (2001). Vancomycin-resistant enterococci: mechanisms and clinical observations. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 33(2), 210–219. https://doi.org/10.1086/321815
Miller, W. R., Munita, J. M., & Arias, C. A. (2014). Mechanisms of antibiotic resistance in enterococci. Expert review of anti-infective therapy, 12(10), 1221–1236. https://doi.org/10.1586/14787210.2014.956092.
Downloads
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
You are free to:
- Share — copy and redistribute the material in any medium or format
- Adapt — remix, transform, and build upon the material for any purpose, even commercially.
Terms:
- Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
