Type II toxin- antitoxin systems in clinical isolates of antibiotic resistant Acinetobacter baumannii

Abstract

The over use of antibiotics to treat infections in humans and animals made a phenomenon of the antibiotic-resistant bacteria. While studies focused to find on new antibiotics but, identification of novel antibacterial targets in bacteria is very important. By Toxin antitoxin systems this hypothesis could be done, whereas by the activation of a toxin or inactivation of an antitoxin, the raised toxin kills the bacterium. These systems are attractive target for antimicrobial therapy. However, the most important step for potency of TA system, as an antibacterial target, is to identify a TA system that is prevalent in all resistant clinical isolates. So, the prevalence of different TA systems among clinical isolates of Acinetobacter baumannii in Emam khomeini hospital, Ilam, Iran was evaluated to determine which TA system is prevalent in all antibiotic resistant A. baumannii. So, one hundred A. baumannii clinical isolates were identified during one-year period in Emam khomeini hospital, Ilam, Iran. A. baumannii clinical isolates were isolated from hospitalized patients in ICU and burn patients. All isolates were resistant to at least one antibiotic. Then, the isolates were subjected to evaluation to find mazEF and higBA TA genes by PCR. The results showed the frequency of mazEF and highBA TA genes in all isolates was 72% and 39%, respectively. mazEF or higBA TA systems are not presented in all isolates. So, the potency of these two TA systems are in challenged. Also, all isolates were not positive for one TA gene. So, more research in different geographical area should be done with functionality of TA genes.