Change in Antibiotic Susceptibility Pattern of Clinical Bacterial Isolates from Two Hospitals in Dhaka, Bangladesh over a Period of Three Years
Mahnaz Hossain Fariba
Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
Abdullah Bashar Sami
Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
Debanjan Bhattacharjee
Department of Mathematics, Utah Valley University, Orem, UT 84058, USA.
Sajal Kumar Saha
Department of Clinical Pharmacy and Pharmacology, University of Dhaka, Dhaka, Bangladesh.
Sitesh Chandra Bachar
Department of Pharmaceutical Technology, University of Dhaka, Dhaka, Bangladesh.
M. Aftab Uddin
Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
Ruhul Haque Kuddus *
Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh and Department of Biology, Utah Valley University, Orem, UT 84058, USA.
*Author to whom correspondence should be addressed.
Abstract
Introduction: It is established that improper use of antibiotics leads to rapid development of bacterial antibiotic resistance. We investigated changes in the antibiotic susceptibility pattern of pathogenic bacteria in a megacity where improper antibiotic use is common.
Methodology: Data on the antibiotic susceptibility pattern of clinical isolates to 28 commonly used antibiotics was obtained from two hospitals at time point A (Jan-Dec 2009, or Nov-Dec 2010) and at about 12-36 months later (time point B), and the data were compared using the one-sided test for equality of proportions. For large samples, tests using Z-score and normal distribution were conducted; for small samples, Fisher’s exact test was performed.
Results: Of the 194 different pairs of isolate clusters compared; 66.5% of the cluster-pairs showed no change in the antibiotic susceptibility pattern. Of the remaining 33.5% of the isolate clusters, the time point B clusters showed a significant decrease in antibiotic susceptibility in 21.1% of the cases, and a significantly higher susceptibility in 12.4% of the cases, compared to the corresponding time point A clusters. The decreased antibiotic susceptibility was observed in 20.0% of the Gram-negative and 24.1% of the Gram-positive bacterial isolate clusters; and the increased antibiotic susceptibility was observed in 10.0% of Gram-negative and 18.5% of Gram-positive bacterial clusters.
Conclusions: Antibiotic resistance and susceptibility of Gram-positive and Gram-negative pathogenic bacteria may significantly change over a period as short as 1-3 years. Continuous vigilance of such changes in a region may allow development of regional strategies for rational antibiotic use.
Keywords: Antibiotic-susceptibility, antibiotic-resistance, equality of proportions test, Fisher’s exact test