Colistin as A Good Monotherapy to Restrain the Pathogenicity of Acinetobacter baumannii In vivo and In vitro

المجلة: Baghdad Science Journal

سنة النشر: 2021

تاريخ النشر: 2021-09-20

stract: Acinetobacter baumannii (A. baumannii) is a major opportunistic nosocomial pathogen, mostly resistant to several groups of antibiotics. Colistin is now used as a last-line treatment for isolates that are highly resistant. The purpose of this study is to identify the importance of LptD; which is involved in the translocation of LPS from the inner membrane to the outer membrane in compartment with LptA and LptC of A. baumannii and its indispensable role as a virulence factor, and the efficiency of colistin as a monotherapy. In the current research, two isolates of A.baumannii were used, the local isolate HHR1 isolated from urine sample and the global strain ATCC 17904, and three antibiotics (colistin, rifampicin and Fosfomycin) were used as a monotherapy and synergic therapy in vivo and ex vivo. The results demonstrated that A. baumannii HHR1 was more resistant to Antimicrobial peptides (AMPs) than the standard strains. The effect of AMPs on A. baumannii was increased by increasing the concentration and the time of incubation, and also AMPs were shown to be lethal on A. baumannii growth spatially at high concentration (2 µg ml-1) in monotherapy and (1.5, 2 µg ml-1) in synergic. The susceptibility of isolates towards antibiotics was variable, where colistin exerts significant growth had defect as a monotherapy and in combination with others. The results showed that the expression of lptD, lptA genes of A.baumannii HHR1 were higher than of the same genes in A.baumannii ATCC 17904 in the presence of 2 µg ml-1 colistin, while lptE gene of the A.baumannii ATCC 17904 showed an upregulation pattern than in A.baumannii HHR1. Furthermore, colistin influences the adhesion ability of A. baumannii on epithelial cells (A-549 lung cancer cell) by reducing the number of cells, and thus could colistin be a good candidate for A. baunmannii treatment.

Effect of sodium chloride on Acinetobacter baumannii growth and Lipopolysaccharide component

المجلة: AIP Conference Proceedings 2398, 040025 (2022); https://doi.org/10.1063/5.0097469

سنة النشر: 2022

تاريخ النشر: 2022-10-25

Abstract: Acinetobacter baumannii is a major opportunistic nosocomial pathogen. Sodium chloride is one of the elements that necessary for the survival of some bacterial species. The purpose of this study is to identify the effect of NaCl on A. baumannii . In this study two isolates of A. baumannii have been used, the local isolate HHR1 and the global isolate ATCC 17904. Firstly, the influence of NaCl on the growth of two isolates of A. baumannii was monitored and the effect of two concentrations of NaCl on Lipopolysaccharide components was determined by SDS-PAGE. The result showed that HHR1 after 20 hr of incubation period was reached to 0.6 at OD600 in the presence of salt, while the control was continued, whereas, and A. baumannii ATCC didn’t exert any defect growth. Moreover, NaCl has greatly affected the LPS components, where only O-antigen has been appeared under 1% NaCl in A. baumannii HHR1 and 3% NaCl in A. baumannii ATCC.