Prevalence Determination of Virulence Related and Biofilm Formation Genes in Acinetobacter baumannii Isolates from Clinical Respiratory Samples in Imam Khomeini Hospital, Tehran, Iran in 2018

Abstract

Background and Aim: Acinetobacter baumannii is considered to be a re-emerging causative agent of nosocomial infections. There is a significant relation between pathogenicity of this bacterium and the numerous virulence factors. The purpose of this study was to investigate nine virulence factor genes in A. baumannii isolates derived from hospitalized patients. Materials and Methods:A total of 50 A. baumannii isolates were recovered from patients with pneumonia in Imam Khomeini Hospital, Tehran, Iran. Following biochemical and microbiological identification of the bacteria, Multiplex PCR was performed for basD, plD, csuA genes, surA, pbpG, bfmR genes, and bap, ompA genes using specific sets of primers which were specifically designed for this study. The espA was identified separately by a Uniplex PCR assay. All amplified DNA fragments were sequenced for the products' confirmation.Results: Among the 50 clinical isolates of A. baumannii studied, bfmR and pbpG genes were reported in all samples (100%), bap, plD, surA, and csuA genes were collected from 49 samples (98%), 48 (96%) of these isolates had ompA and basD genes, and espA gene was observed in only five isolates (10%). Conclusion:According to this study results, virulence factors genes in clinical A. baumannii have a prevalence rate more than 90%. Additionally, the high incidence rate of those genes related to biofilm formation indicates that most clinical strains have the ability to form biofilm structures.

Virulence Molecular Epidemiology of Clinical Carbapenem-Resistant Acinetobacter baumannii: First Report from Jordan

“…It enhances the persistence of A. baumannii in the hospital environment, and promotes antibiotic resistance and tolerance to other inhibitors [12,13] Surface antigen protein surA1 Surface antigen protein is a periplasmic chaperone protein necessary for cellular invasion. Iron acquisition system BasD Iron acquisition system is essential for bacterial survival and growth in a host under iron-limited conditions [14] Phospholipase D Pld Phospholipase D enhances A. baumannii ability to thrive in serum and invade epithelial cells [15] Outer membrane protein A OmpA Outer membrane protein A (OmpA) is an adhesion protein enhances bacterial attachment to eukaryotic epithelial cells and formation of biofilms [16]…”

Molecular and virulence characteristics of carbapenem-resistant Acinetobacter baumannii isolates: A prospective cohort study

“…Thirteen virulence genes (basD, espA, ompA, bap, bfmR, pbpG, fhaB, cpaA, ata, recA, lipA, abeD, and chop) and two carbapenemase genes (bla OXA−23 and bla OXA−51 ) were detected using speci c primers (Supplementary Table S1). Virulence genes were associated with siderophore synthesis (basD), bacterial adhesion (espA, bap, ata, chop), bio lm formation (ompA, pbpG), glycoconjugates (bfmR), host cell death (fhaB, abeD), toxin production (cpaA, lipA), and stress response (recA) [17][18][19][20]. The PCR cycling conditions were as follows: denaturation at 95 ℃ for 5 min, annealing between 50 ℃ and 61 ℃ for 30-45 s, and extension at 72 ℃ for 1 min (for 34 cycles).…”