Correlation of Virulence Factors and Cell Adhesion of Clinical Isolates of Acinetobacter baumannii

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.
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.
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.
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.