Multidrug-resistant Acinetobacter baumannii: differential adherence to HEp-2 and A-549 cells

Abstract

Acinetobacter baumannii has been associated with antimicrobial resistance and ability to form biofilms. Furthermore, its adherence to host cells is an important factor to the colonization process. Therefore, this study intended to identify some virulence factors that can explain the success of A. baumannii in causing nosocomial infections. We studied 92 A. baumannii isolates collected from hospitals in Rio de Janeiro, Brazil. Isolates were identified and the susceptibility to antimicrobials was determined. Oxacilinase type β-lactamase encoding genes were amplified by polymerase chain reaction, and genetic diversity was investigated by pulsed-field gel electrophoresis (PFGE). In addition, biofilm formation on polystyrene plates using crystal violet staining was quantified, and adherence to human cell lines was evaluated. Eighty-six isolates were multidrug-resistant, of which 93% were carbapenem-resistant. All isolates had the bla OXA-51 gene and 94% had the bla OXA-23 gene, other searched bla OXA genes were not detected. PFGE typing showed two predominant clones, and biofilm production was observed in 79% of isolates. A. baumannii isolates adhered better to HEp-2 cell compared with A-549 cell. Clones A, B, E, and F showed a significantly increased adherence to HEp-2 compared with adherence to A-549 cell. Our findings revealed that A. baumannii isolates had high frequencies of resistance to antimicrobial agents, ability to form biofilm, and capacity to adhere to HEp-2 cells.

Adherence ability and serum resistance of different hospital clusters of Acinetobacter baumannii

“…Another study conducted with isolates from public hospitals in the city of Rio de Janeiro, Brazil, found greater adherence to HEp‐2 cells than to A549 cells (Genteluci et al . 2020). In our study, all isolates adhered to HEp‐2 cells, with varying degrees of intensity (Table 1).…”

“…Differences amongst clusters could explain these differences in the rates of adherence to human cells that occurred in the isolates of the clusters analyzed (Genteluci et al . 2020).…”

“…2017; Genteluci et al . 2020). Little is known about the pattern of adherence of A. baumannii and the role that cell‐surface hydrophobicity may play in adherence to host cells as well as to abiotic surfaces (Skerniškytė et al .…”

Genotypic patterns of multidrug-resistant Acinetobacter baumannii: A systematic review

“…Higgins et al .,[ 20 21 ] and other studies detected oxacillinases and MBLs such as blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, blaOXA-143, bla IMP, blaVIM, bla GIM, bla SMP , and bla NDM in MDR A. baumannii . [ 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 51 52 53 54 55 68 69 70 71 72 73 74 75 76 77 79 ]…”

“…[ 12 ] In the study by Higgins and other studies, the blaOXA-23 gene was detected in MDR A. baumannii . [ 20 21 22 23 24 27 34 35 37 38 40 43 45 49 52 54 68 69 73 76 79 ]…”