Antimicrobial Resistance Patterns of Gram-Negative Bacteria in an Iranian Referral Pediatric Hospital: A Present Danger of New Delhi Metallo-Β-Lactamase Publisher Pubmed



Mahmoudi S^{1, 2} ; Pourakbari B^{1, 2} ; Rostamyan M³ ; Raji H⁴ ; Sadeghi RH¹ ; Mamishi S^{1, 3} Show Affiliations
Source: Infectious Disorders - Drug Targets Published:2023

Abstract

Background: Antimicrobial resistance among gram-negative bacteria has been growing, particularly in developing countries, like Iran. The emergence and spread of carbapenem-resistance mechanisms is a major public health concern because no definite treatments have yet been established for this problem. This study aimed to evaluate antibiotic susceptibility of gram-negative bacteria, metallo-β-lactamases (MBLs) and carbapenemase-producing genes, including blaNDM, bla VIM, and blaIMP in patients referred to Children’s Medical Center, Tehran, Iran. Material and Methods: In this cross-sectional study, a total of 944 gram-negative isolates were tested in the study, and antimicrobial susceptibility testing was performed. Moreover, MBL production of carbapenem-resistant isolates, as well as the presence of blaNDM, blaVIM, and blaIMP, was investigated. Results: The most common gram-negative isolated bacteria were Escherichia coli (489 samples, 52%), followed by Klebsiella pneumoniae (167 samples, 18%), Pseudomonas aeruginosa (101 samples, 11%), Enterobacter spp. (64 samples, 7%), Pseudomonas spp. (35 samples, 4%), Acinetobacter baumannii (18 samples, 2%), and Burkholderia cepacia (17 samples, 2%). Imipenem-resistant was found in 75%, 61%, and 60% of Stenotrophomonas maltophilia, Enterobacter spp., and A. baumannii isolates, respectively. Moreover, the highest resistance to meropenem was observed in S. maltophilia, A. baumannii, P. aeruginosa, and B. cepacia (100%, 96%, 83%, and 61.5%, respectively). Double disk synergy test (DDST) results showed that 112 out of 255 car-bapenem-resistant isolates (44%) were MBL-producing ones. The presence of the blaNDM gene was identified in 32 (29%) of MBL-producing isolates, 13 of which were K. pneumoniae, 7 P. aeruginosa, and 7 E. coli, 3 Enterobacter spp., and 2 Klebsiella spp., respectively. The presence of the blaIMP and blaVIM genes was detected in 2 (2%) and 1 (1%) of MBL-producing isolates. These genes were detected in only MBL-producing P. aeruginosa isolates. Conclusion: Our findings suggest the emergence of NDM-producing strains in our hospital, and blaNDM was the most frequently detected carbapenemase gene in MBL-producing P. aeruginosa, K. pneumoniae, and Klebsiella spp. Since such bacteria can easily spread among patients in the hospital, a strong infection control and prevention plan is highly recommended. © 2023 Bentham Science Publishers.