Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jun 26:8:1144.
doi: 10.3389/fmicb.2017.01144. eCollection 2017.

Antivirulent Properties of Underexplored Cinnamomum tamala Essential Oil and Its Synergistic Effects with DNase against Pseudomonas aeruginosa Biofilms - An In Vitro Study

Sanaulla Farisa Banu  1 , Durairajan Rubini  1 , Sairam Rakshitaa  1 , Kamaraj Chandrasekar  2 , Ramar Murugan  3 , Aruni Wilson  4 , Shanmugaraj Gowrishankar  5 , Shunmugiah Karutha Pandian  5 , Paramasivam Nithyanand  1   6
Affiliations

Antivirulent Properties of Underexplored Cinnamomum tamala Essential Oil and Its Synergistic Effects with DNase against Pseudomonas aeruginosa Biofilms - An In Vitro Study

Sanaulla Farisa Banu et al. Front Microbiol. .

Abstract

Pseudomonas aeruginosa is a nosocomial pathogen colonizing patients with chronic infectious diseases and has gained resistance to all the known broad spectrum antibiotics available today. The present study showcases the antibiofilm potential of an essential oil (EO) from an underexplored Cinnamomum species namely, C. tamala, against P. aeruginosa biofilms. Furthermore, the synergistic effects of the EO along with a commercially available DNase (DNaseI) and a DNase (MBD) isolated from a marine bacterium were explored for its antibiofilm activity. The results showed that the synergized action has maximum efficacy in inhibiting young and preformed biofilms. The synergized effect of EO and DNaseI showed 70% inhibition against matured biofilms of P. aeruginosa. The EO from C. tamala also showed quorum sensing inhibitory potential as it could inhibit the swarming motility behavior of P. aeruginosa. The synergistic action of EO and DNases offers a novel alternate therapeutic strategy for combating P. aeruginosa biofilm associated infections.

Keywords: Almora; Cinnamomum essential oil; DNase; biofilm; synergism.

PubMed Disclaimer

Figures

FIGURE 1
FIGURE 1
Growth curve of P. aeruginosa treated with EO of C. tamala after 24 h incubation.
FIGURE 2
FIGURE 2
Percentage inhibition of P. aeruginosa young biofilm. Mean values of triplicate of independent experiments ± SD are shown. One-way ANOVA test demonstrates significant difference between the control and the test. Double asterisk indicates significant at P ≤ 0.01 and triple asterisk indicates significant at P ≤ 0.005.
FIGURE 3
FIGURE 3
Percentage inhibition of P. aeruginosa matured biofilm. Mean values of triplicate independent experiments ± SD are shown. One-way ANOVA test demonstrates significant difference between the control and the test. Double asterisk indicates significant at P ≤ 0.01 and triple asterisk indicates significant at P ≤ 0.005.
FIGURE 4
FIGURE 4
Light microscopic images at 40× demonstrate the inhibition of P. aeruginosa young biofilm. (A) Control, (B) EO treated, (C) DNaseI treated, (D) MBD treated, (E) EO + DNaseI, (F) EO + MBD.
FIGURE 5
FIGURE 5
CLSM reveals the architecture of P. aeruginosa matured biofilm dispersal. (A) Control, (B) EO treated, (C) DNaseI treated (D) MBD treated, (E) EO + DNaseI, (F) EO + MBD.
FIGURE 6
FIGURE 6
Scanning Electron Microscopic image of P. aeruginosa biofilm (A) Control, (B) DNaseI treated, (C) MBD treated. Black arrow in (A) control indicates the EPS forming matrix.
FIGURE 7
FIGURE 7
Fluorescent microscopy image of P. aeruginosa eDNA. Propidium iodide (PI) stained eDNA in red. (A) Control, (B) DNaseI treated, (C) MBD treated.
FIGURE 8
FIGURE 8
Inhibitory Effect of EO at sub MIC (5% v/v) on EPS production of P. aeruginosa biofilm. Mean values of triplicate independent experiments ± SD are shown. One-way ANOVA test demonstrates significant difference between the control and the test. Double asterisk indicates significant at P ≤ 0.01.
FIGURE 9
FIGURE 9
Inhibition of alginate production (A) P. aeruginosa biofilm in the presence of EO (1–5% v/v), (B) AU07-PACI-01 biofilm in the presence of EO (1.8–7% v/v), (C) AU09-PACI-02 biofilm in the presence of EO (1.8–7% v/v). Mean values of triplicate independent experiments ± SD are shown. One-way ANOVA test demonstrates significant difference between the control and the test. Single asterisk indicates significant at P ≤ 0.025 and triple asterisk indicates significant at P ≤ 0.005.
FIGURE 10
FIGURE 10
Inhibition of staphylolytic activity (A) P. aeruginosa biofilm by EO treated (1–5% v/v), (B) AU07-PACI-01 biofilm in the presence of EO (1.8–7% v/v), (C) AU09-PACI-02 biofilm in the presence of EO (1.8–7% v/v). Mean values of triplicate independent experiments ± SD are shown. One-way ANOVA test demonstrates significant difference between the control and the test. Single asterisk indicates significant at P ≤ 0.025 and triple asterisk indicates significant at P ≤ 0.005.
FIGURE 11
FIGURE 11
Inhibition of pyocyanin (A) P. aeruginosa biofilm by EO treated (1–5% v/v), (B) AU07-PACI-01 biofilm in the presence of EO (1.8–7% v/v), (C) AU09-PACI-02 biofilm in the presence of EO (1.8–7% v/v). Mean values of triplicate independent experiments ± SD are shown. One-way ANOVA test demonstrates significant difference between the control and the test. Single asterisk indicates significant at P ≤ 0.025, double asterisk indicates significant at P ≤ 0.01, and triple asterisk indicates significant at P ≤ 0.005.
FIGURE 12
FIGURE 12
Effect of EO on swarming motility of (A) P. aeruginosa in a concentration dependent manner. (a) Control, (b) EO Treated (1.25% v/v), (c) (2.5% v/v), (d) (5% v/v). (B) AU07-PACI-01 (a) Control, (b) EO Treated (1.8% v/v), (c) (3.5% v/v), (d) (7% v/v). (C) AU09-PACI-02 (a) Control, (b) EO Treated (1.8% v/v), (c) (3.5%v/v), (d) (7% v/v).
See this image and copyright information in PMC

References

    1. Bassole I. H., Juliani H. R. (2012). Essential oils in combination and their antimicrobial properties. Molecules 17 3989–4006. 10.3390/molecules17043989 - DOI - PMC - PubMed
    1. Bayes H. K., Ritchie N., Irvine S., Evans T. J. (2016). A murine model of early Pseudomonas aeruginosa lung disease with transition to chronic infection. Sci. Rep. 6:35838 10.1038/srep35838 - DOI - PMC - PubMed
    1. Brackman G., Defoirdt T., Miyamoto C., Bossier P., Calenbergh S. V., Nelis H., et al. (2008). Cinnamaldehyde and cinnamaldehyde derivatives reduce virulence in Vibrio spp. By decreasing the DNA-binding activity of the quorum sensing response regulator LuxR. BMC Microbiol. 8:149 10.1186/1471-2180-8-149 - DOI - PMC - PubMed
    1. Chung P. Y., Toh Y. S. (2014). Anti-biofilm agents: recent breakthrough against multi-drug resistant Staphylococcus aureus. Pathog. Dis. 70 231–239. 10.1111/2049-632X.12141 - DOI - PubMed
    1. Clinical and Laboratory Standards Institute (2006). Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically. Clinical and Laboratory Standards Institute document M7-A7 7th Edn Wayne, PA: Clinical and Laboratory Standards Institute.

LinkOut - more resources