Transcriptomic Analysis of Drug-Resistance Acinetobacter baumannii under the Stress Condition Caused by Litsea cubeba L. Essential Oil via RNA Sequencing

Abstract

Litsea cubeba L. essential oil (LCEO) can affect the growth of drug-resistance bacteria. However, research on stress response of drug-resistant A. baumannii under sub-lethal LCEO concentrations had been limited so far. Therefore, transcriptomic analysis of A. baumannii under 1/2 minimum inhibitory concentration (MIC, 0.54 mg/mL) of LCEO was performed. Results of transcriptomic analysis showed that 320/352 genes were significantly up/down-regulated, respectively, in LCEO-treated A. baumannii. Both up and down-regulated genes were significantly enriched in three GO terms (oxidation-reduction process; oxidoreductase activity; oxidoreductase activity, acting on the CH-CH group of donors), which indicated that the redox state of A. baumannii was significantly affected by LCEO. LCEO may also inhibit aerobic respiration, synthesis of ketone bodies and the metabolism of some amino acids while, meanwhile, promoting fatty acid degradation of A. baumannii according to Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. The permeability and the stress of cell membrane of A. baumannii were significantly affected by LCEO. After crystal violet dyeing, the biofilm formation of A. baumannii was promoted/inhibited by extremely low/relatively high concentration of LCEO, respectively. LCEO and chloramphenicol have synergistic growth inhibitory effect against A. baumannii according to the Fractional Inhibitory Concentration Index (FICI) value = 0.375. Our results indicate that the growth of A. baumannii was inhibited by LCEO, and give insights into the stress response of A. baumannii under sub-lethal concentrations of LCEO. These results provided evidence that A. baumannii was inhibited by LCEO, and expanded knowledges of stress response of A. baumannii under sub-lethal concentration of LCEO.

Inhibition of Acinetobacter baumannii Biofilm Formation Using Different Treatments of Silica Nanoparticles

“…The MBIC value for amoxicillin was 625 µg/mL in this study, in contrast to other studies, which revealed the MBIC value as being 800 µg/mL [ 11 ]. In comparison to the result for amoxicillin, the different silica NPs (pure, composite, alkali, and H 3 PO 4 .SiO 2 ) used in this study showed an inhibition effect for the biofilm by reducing absorbance values at various concentrations (from 1.0 mg/mL to 0.125 mg/mL), according to Figure 6 .…”

“…It has the potential to produce biofilm and cause infections in both individuals who have been hospitalized for extended durations as well as those who have been exposed to prolonged antimicrobial therapy [ 8 , 9 , 10 ]. It has been observed that A. baumannii , which is resistant to antibiotics, exhibits a robust ability to form biofilms [ 11 ]. The ability of bacterial cells to coordinate their gene expression through quorum sensing (QS) allows for the development of a multi-drug resistance feature that enables adaptation to change in environmental conditions, specifically in the form of biofilm [ 12 ].…”

Antibacterial activity and mechanism of X33 antimicrobial oligopeptide against Acinetobacter baumannii

“…Among them, H0N28_14510 encoding the two-component system sensor histidine kinase PmrB, H0N28_14515 encoding the DNA-binding response regulator PmrA, H0N28_00400 encoding imidazolone propionase, and hutG encoding formimidoylglutamase were significantly downregulated ( Table 3 ). The changes in the expression of these genes were similar to those in A. baumannii treated with L. cubeba essential oil [ 28 ]. Based on the findings of cell content leakage, SEM, and additional integration with the transcriptome data, X33AMOP interferes with the cell membrane to exert an effect on it.…”

Inhibition of Cronobacter sakazakii by Litsea cubeba Essential Oil and the Antibacterial Mechanism

“…The killing effect of LC-EO on other bacteria also shows this trend. Time dependence and concentration dependence were characteristic of the reduction in drug-resistant Acinetobacter baumannii , as determined by measuring OD 600 nm at intervals [ 49 ]. Thielmann et al [ 50 ] reported that on the surface of food packaging films and across the gas phase, LC-EO achieved bactericidal effects against E. coli in a time-dependent manner.…”