Correlation of Virulence Factors and Cell Adhesion of Clinical Isolates of <i>Acinetobacter baumannii</i>

Abstract

Background: Adhesion to host cells is an important and critical feature of Acinetobacter baumannii pathogenesis. OmpA, ABAYE1319-CsuA/b, and ABAYE2132 are highly prevalent and conserved fimbrial proteins; ABAYE1859 and ABAYE0304 fimbrial antigens are the factors described as novel vaccine candidates against multidrug-resistant (MDR) A. baumannii. Methods: The current study aimed at investigating the significance of A. baumannii fimbrial and outer membrane proteins A (OmpA) in adherence to human epithelial cells. Antibiotic resistance was determined by the broth microdilution method. Phenotypic identification of isolates producing ESBL (extended-spectrum beta-lactamase) was conducted using double-disc synergy test (DDST). The virulence factors were detected by the polymerase chain reaction (PCR) in 100 non duplicate clinical isolates of A. baumannii; 18 clinical isolates were selected for adhesion assay based on antibiotic resistance and PCR results. Results: The current study results showed that ABAYE2132, ABAYE0304, and ABAYE1319- CsuA/B had significant correlation with cell adhesion (P ≤ 0.05). There was no significant correlation between cell adhesion and ABAYE1859 (P ≥ 0.05). ABAYE2132 was the most effective factor in cell adhesion. It was also observed that cell adhesion rate reduced with the increase of fimbrial proteins. Conclusions: The current study findings suggested that different products and structures of A. baumannii, most still unknown, play a pivotal role in pathogen-biotic reactions. Better exposure of some non-pili adhesins or other biofilm forming factors could be a reason for this phenomenon.