Research Article
Characterization of Clinical Isolates of Enterococci with Special
Reference to Glycopeptide Susceptibility at a Tertiary Care
Center of Eastern Nepal
Aasish Karna ,
1
Ratna Baral ,
2
and Basudha Khanal
2
1
B.P. Koirala Institute of Health Sciences, Dharan, Nepal
2
Department of Microbiology and Infectious Diseases, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
Correspondence should be addressed to Aasish Karna; cricaasish@gmail.com
Received 25 November 2018; Revised 4 February 2019; Accepted 26 May 2019; Published 1 July 2019
Academic Editor: Todd R. Callaway
Copyright © 2019 Aasish Karna et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background. Enterococci, once considered as a harmless commensal of intestine, have now emerged as medically important
pathogens and are associated with both community-acquired and nosocomial infections. ey bear the potential to exhibit
resistance against all commonly used antibiotics either by inherent or acquired mechanism, posing a therapeutic challenge.
Objectives. is study aimed to characterize enterococci up to the species level and study their antibiogram with special regard to
vancomycin. Methods. A descriptive cross-sectional study was conducted in the Department of Microbiology, B.P. Koirala
Institute of Health Sciences, Dharan, Nepal, from February to May 2017. A total of 91 enterococcal isolates recovered from clinical
specimens were investigated in this study. eir identification and speciation were done according to standard microbiological
guidelines. Kirby–Bauer disc diffusion technique was used to study antimicrobial susceptibility pattern, whereas minimum
inhibitory concentration of vancomycin was determined by the agar dilution method, with reference to Clinical and Laboratory
Standards Institute guidelines. Results. Seven different species of enterococci were isolated, E. faecalis and E. faecium accounting
about 45% each. e other species encountered were E. avium, E. cecorum, E. dispar, E. durans, and E. raffinosus. Highest
proportion of antimicrobial susceptibility was recorded for linezolid (97.8%), followed by teicoplanin (95.6%) and high-level
gentamicin (81.3%). Sensitivity to vancomycin was seen in 79.1% isolates. Likewise, 82.1% of urinary strains were susceptible to
nitrofurantoin. A total of 4 disparities were observed between the disc diffusion technique and agar dilution method in de-
termining vancomycin resistance. Multidrug resistance was observed in 31.9% isolates. e overall prevalence of vancomycin-
resistant enterococci based on the standard minimum inhibitory concentration method was 25.3%. Conclusions. Enterococcus
faecalis and E. faecium were the predominant species in causing enterococcal infections. e alarming rise in prevalence of
vancomycin and multidrug resistance strains warrants immediate, adequate, and efficient surveillance program to prevent and
control its spread.
1.Introduction
Enterococci are Gram-positive, facultatively anaerobic cocci
that may occur in pair or short chains [1]. More recently,
they are gaining greater attention because of their ability to
withstand the effect of multiple antimicrobial agents, con-
sequently limiting the therapeutic options and resulting in
high mortality and morbidity. Tracking the distribution of
enterococci and the knowledge of their antibiogram is of
utmost importance in order to prevent and control its spread
[2]. ey bear the potential to cause a wide range of in-
fections, for instance, urinary tract infections, surgical site
infection, bacteremia, intra-abdominal and intra-pelvic
abscess, and occasionally, meningitis and pneumonia
[3, 4]. Enterococci exhibit low-level resistance to all ami-
noglycosides, indicating poor efficacy in clinical practice.
e predisposing factors associated with rise in enterococcal
infections are empirical use of antimicrobial agents, pro-
longed hospitalization, invasive therapy, and wide use of
immunosuppressant [2, 5, 6]. eir capability of transferring
Hindawi
International Journal of Microbiology
Volume 2019, Article ID 7936156, 8 pages
https://doi.org/10.1155/2019/7936156