Vol 11, Issue 8, 2018
Online - 2455-3891
Print - 0974-2441
CONSUMPTION AND BACTERIAL RESISTANCE TO AMINOGLYCOSIDES AT SUDANESE
UNIVERSITY HOSPITAL
EINAS A BAKHEIT
1
, KAMAL M ELHAG
2
, ABDUELMULA R ABDUELKAREM
3
*, NADA A BASHEER
4
1
Department of Pharmaceutics, Clinical Pharmacy Program, University of Khartoum, Sudan.
2
Department of Microbiology, Ahfad
University for Women, Omdurman, Sudan.
3
Department of Pharmacy Practice and Pharmacotherapeutics, College of Pharmacy, University
of Sharjah, P.O. Box 27272, Sharjah, UAE.
4
Department of Microbiology, International University of Africa, Sudan.
Email: aabdelkarim@Sharjah.ac.ae
Received: 02 April 2018, Revised and Accepted: 10 May 2018
ABSTRACT
Objectives: The objective of this study was to describe patterns of antimicrobial resistance to gentamicin (Gen) and amikacin (Ak) among Gram-
negative aerobic bacteria during 1-year period and to determine the association between antibiotic resistance and the consumption of Gen.
Methods: Aminoglycosides consumption at Soba University Hospital wards was measured and susceptibility of Gram-negative bacteria for the same
period was evaluated. Consumption data were converted to defined daily doses (DDDs)/100 bed days based on DDD/anatomical therapeutic chemical
the WHO system. The association between the frequency of strains resistant to Gen and Ak and their consumption was assessed by linear regression
analysis using Spearman’s correlation. The level of statistical significance was set at p<0.05.
Results: A total of 973 Gram-negative isolates were identified and tested for antimicrobial susceptibility to Gen and Ak. Resistance to Gen alone
was found to be 19.42%; n=189, resistance to Ak alone was found to be 3.08%; n=30, and resistance to Gen plus Ak was found to be 5.24%; n=51.
Pseudomonas aeruginosa was the most resistant pathogen to Ak plus Gen (2.26%; n=22). A positive correlation between the increases in the use of
Gen and the prevalence of bacterial resistance among hospital wards was found (correlation coefficient r=0.6; p=0.04).
Conclusion: Gen and Ak are still highly active antimicrobial agents for the treatment of aerobic Gram-negative bacteria at times of intensified
resistance to other antimicrobial agents. Monitoring the use of aminoglycosides is very important too.
Keywords: Aminoglycosides, Resistance, Gram-negative bacteria, Hospital Prescribing, Sudan.
INTRODUCTION
After seven decades in clinical use, aminoglycoside antibiotics still
remain crucial drugs for the treatment of acute infections and specific
conditions such as tuberculosis. They are especially effective in the
containment of Pseudomonas bacteria in patients with cystic fibrosis,
regardless of the harmful side effects that are being gradually solved
by extensive research around the world. The development of bacterial
resistance to aminoglycosides during therapy is rare [1], and the
prevalence of resistance to aminoglycoside remained relatively low
compared to cephalosporins or fluoroquinolones [2].
The most predominant resistance mechanism is through aminoglycoside-
modifying enzymes. Resistance may occur when bacteria produce
16S rRNA methylases, which cause high level and broad-spectrum
aminoglycoside resistance [3]. Other resistance mechanisms do exist,
which can act simultaneously in the same cell [4]. These include reduced
permeability by modification of outer membrane or diminished inner
membrane transport [5], export outside the cell by activation of efflux
pumps [6,7], adaptive resistance [8], active swarming, and a non-specific
mechanism newly shown in Pseudomonas aeruginosa cells specially
against gentamicin (Gen), which revealed adaptive antibiotic resistance
against numerous antibiotics [9] and sequestration of the drug by tight
binding to an altered aminoglycoside acetyltransferase [10].
Aminoglycoside-modifying enzymes catalyze the modification at −
OH or −NH2 groups of the 2-deoxystreptamine nucleus or the sugar
moieties and can be acetyltransferases, nucleotidyltransferases, or
phosphotransferases [11,12].
The DDD is known as the average standard daily dose of a drug used
in an adult assuming 70 KGs as average weight [13]. DDD has been
used extensively to compare frequencies of antimicrobial use between
wards, hospitals, and even countries. A small number of studies have
used the DDD methodology in children with justification [14-17].
The use of the adult Anatomical Therapeutic Chemical (ATC)/DDD
methodology to compare pediatric to adult antibiotic prescribing is
misleading because it does not take into account either age or weight
of the child. Accordingly, the total DDD from an adult ward would
be much higher than that for a neonatal ward, which makes straight
judgments very challenging between hospitals or wards containing
such problem. When the use of antibiotic in adult ward is negligible,
and the same antibiotic is extensively used in pediatric wards such
problem will not affect the significance of consumption variation. The
practice mentioned above is because pediatricians are very adherent
to sepsis management guidelines, which is the most prevalent disease
among pediatric and neonate patients in our institution, while other
practitioners always find the way to skip aminoglycosides for another
option even if the culture results are positive. That is because of low
knowledge about aminoglycosides, their efficacy, low resistance rate
and finally the ghost of nephrotoxicity and ototoxicity.
In the last years, several studies were carried out to determine the
relationship between consumption of antimicrobial agents and the
development of bacterial resistance and build a hypothesis of a
positive correlation. In a study, which investigated the development of
resistance in Gram-negative bacteria and evaluated its association with
consumption of various groups of antibiotics, a statistically significant
© 2018 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.
org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ajpcr.2018.v11i8.26381
Research Article