Rectal and Tracheal Carriage of Carbapenemase Genes and Class 1 and 2 Integrons in Patients in Neurosurgery Intensive Care Unit

Abstract

The spread of multidrug-resistant Gram-negative bacteria, which is associated with the distribution of beta-lactamase genes and class 1 and 2 integrons, is a global problem. In this study, in the Moscow neurosurgery intensive care unit (neuro-ICU), the high prevalence of the above-stated genes was found to be associated with intestinal and tracheal carriage. Seven-point prevalence surveys, which included 60 patients in the neuro-ICU, were conducted weekly in the period from Oct. to Nov. 2019. A total of 293 clinical samples were analyzed, including 146 rectal and 147 tracheal swabs; 344 Gram-negative bacteria isolates were collected. Beta-lactamase genes (n = 837) were detected in the isolates, including beta-lactamase blaTEM (n = 162), blaSHV (n = 145), cephalosporinase blaCTX–M (n = 228), carbapenemase blaNDM (n = 44), blaKPC (n = 25), blaOXA–48 (n = 126), blaOXA–51–like (n = 54), blaOXA–40-like (n = 43), blaOXA–23-like (n = 8), and blaVIM (n = 2), as well as class 1 (n = 189) and class 2 (n = 12) integrons. One extensively drug-resistant Klebsiella pneumoniae strain (sequence type ST39 and capsular type K23), simultaneously carried beta-lactamase genes, blaSHV–40 and blaTEM–1B, three carbapenemase genes, blaNDM, blaKPC, and blaOXA–48, the cephalosporinase gene blaCTX–M, and two class 1 integrons. Before this study, such heavily armed strains have not been reported, suggesting the ongoing evolution of antibiotic resistance.

Keywords

• rectal and tracheal carriage
• carbapenemase genes
• class 1 and 2 integrons
• neurosurgery
• intensive care unit
• Gram-negative bacteria