CC BY-NC-ND 4.0 · J Lab Physicians 2022; 14(03): 237-246
DOI: 10.1055/s-0042-1750085
Original Article

Antibiogram Pattern and Virulence Trait Characterization of Enterococcus Species Clinical Isolates in Eastern India: A Recent Analysis

Srujana Mohanty
1   Department of Microbiology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India
Bijayini Behera
1   Department of Microbiology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India
› Author Affiliations
Funding This study was funded by the Institute Intramural Research Grant from All India Institute of Medical Sciences (AIIMS), Bhubaneswar (Grant no. AIIMS/BBSR/RC/2016 dated October 17, 2016).


Objective We aimed to evaluate the current antimicrobial susceptibility pattern and characterize putative virulence traits among Enterococcus species isolates from various clinical specimens in view of their increased isolation rates in both community-related and serious nosocomial infections, as well as resistance to many antibiotics.

Methods Study (April 2017–March 2018) included consecutive, nonrepeated, discrete, and clinically significant isolates of enterococci. Susceptibility testing included detection of high-level aminoglycoside-resistant (HLAR) and glycopeptide-resistant enterococci (GRE). All screen-positive GRE isolates were investigated by polymerase chain reaction for species confirmation and presence of vanA/vanB genes. Virulence genes ace, asa1, cyt, efa, esp, gelE, and hyl were investigated by molecular methods. Hemolysin and biofilm production were studied using phenotypic methods.

Results Of 111 isolates, 89 (80.1%), 16 (14.4%), and 6 (5.4%) were from urine, pus, and blood, respectively, consisting predominantly of E. faecalis (67, 60.4%) and E. faecium (32, 28.8%). E. hirae (5, 4.5%) was the predominant non-E. faecalis non-E. faecium isolate. Other species were E. durans (4, 3.6%), E. avium (2, 1.8%), and E. mundtii (1, 0.9%). Seven (6.3%) out of the 111 isolates were GRE, all vanA genotype. HLAR was observed in 70 (63.1%) isolates, significantly higher in E. faecium than E. faecalis (81.2 vs. 58.2%; p < 0.05). All were susceptible to daptomycin. Hemolysin activity and biofilm production were observed in 38 (34.2%) and 36 (32.4%) isolates. Most frequent virulence genes were efa (77, 69.4%), ace (71, 63.9%), asa1 (67, 60.3%), and gelE (66, 59.4%). There was a predominant association of esp and hyl genes with E. faecium and that of the other genes with E. faecalis.

Conclusion The study will contribute to the existing limited data on virulence trait characterization of clinical E. spp. isolates in India. At the same time, it will help to serve as a guide in the choice of empirical therapy in enterococcal infections leading to favorable clinical outcomes by decreasing the clinical failure, microbiological persistence, and associated mortality, and will lead to future studies on controlling the spread of virulent and multiresistant isolates.

Authors' Contributions

S.M. provided substantial contribution to the conception and design of the study, contributed to the acquisition, analysis and interpretation of data for the work, drafted the manuscript, and gave final approval of the version to be published.

B.B. helped in the literature search, contributed in the analysis and interpretation of data, and critically revised the work for important intellectual content.

Source of Support

This study was supported by the Institute Intramural Research Grant from All India Institute of Medical Sciences, Bhubaneswar.


This work should be credited to the Department of Microbiology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India.

Publication History

Article published online:
26 July 2022

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