ABSTRACT
BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic mucosal human pathogen that naturally releases outer membrane vesicles (OMVs) in different environments, as do other Gram-negative bacteria. The intestinal tract infections caused by P. aeruginosa increase the risk of respiratory infections and mortality of other diseases related to gut infections. Therefore, in this study, we attempted to investigate toll-like receptor (TLR) signaling pathways and immune response profiles of human colon adenocarcinoma (Caco2) cell line exposed to the OMVs of three different P. aeruginosa strains (i.e., antibiotic-susceptible, multi-drug resistant (MDR), and standard lab ATCC 17933). MATERIALS AND METHODS: Real-time quantitative reverse transcription PCR array was carried out to determine mRNA expression in 84 TLRs signaling pathway genes, and the production of specific cytokines was measured by ELISA. RESULTS: OMVs of different strains could induce unique changes in regulating TLRs signaling pathways, such that there were remarkable differences in pro-inflammatory effects and anti-inflammatory responses among the three strains. CONCLUSION: The more complete immune responses observed through the MAMPs caused by MDR strain OMVs interactions with Caco2 lead us to the conclusion that the use of MDR or cystic fibrosis strain OMVs for better known the host immune responses seems preferable.
Subject(s)
Bacterial Outer Membrane Proteins/immunology , Epithelial Cells/immunology , Pseudomonas aeruginosa/immunology , Signal Transduction/immunology , Toll-Like Receptors/immunology , Caco-2 Cells , Humans , Toll-Like Receptors/geneticsABSTRACT
BACKGROUND: Multi-drug resistance among Pseudomonas aeruginosa (P. aeruginosa) clinical isolates is increasing and becoming a serious problem for public health authorities worldwide. OBJECTIVE: The aim of the current study is to introduce a potent antibacterial compound against the resistant P. aeruginosa. METHODS: In this study, we evaluated the antibacterial effects of extracts and essential oils of Ferula gummosa Boiss (F. gummosa) on 33 P. aeruginosa clinical isolates by microdilution method and assessed the association of antimicrobial activity with the extended spectrum ß-lactamase (ESBL) producing, biofilm forming and aliginate production of the strains. In addition, the presence of some genes involved in these properties, including blaGES- 1, blaRER-1, blaCTX-M, blaVEB-1, blaOXA-1, blaOXA-4, blaOXA-10, ppyR, pslA, pelA, algU, algL, algD, fliC and oxaA was determined using PCR. RESULTS: We revealed that all of our extracts and essential oils had significant antibacterial effects (p<0.001), but the aqueous extracts showed a relatively lower antibacterial activity compared with the methanolic ones. Furthermore, the minimum inhibitory concentration required for the ESBL producing strains was significantly higher than the non-ESBL producing ones (p<0.001). Loss of some genes such as blaPER-1, blaGES-1, blaOXA-1 and blaOXA-4 caused sensitivity to F. gummosa derivatives (p<0.05). CONCLUSION: The findings of this study indicate that the antibacterial effects of the extract and essential oils of F. gummosa may be a potential novel treatment against drug-resistant P. aeruginosa clinical isolates.
Subject(s)
Ferula/chemistry , Oils, Volatile/pharmacology , Plant Extracts/pharmacology , Pseudomonas aeruginosa/drug effects , Alginic Acid/metabolism , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Microbial Sensitivity Tests , Plant Extracts/chemistry , Pseudomonas aeruginosa/geneticsABSTRACT
Nonencapsulated, nontypeable Hemophilus influenzae (NTHi) remains an important cause of acute otitis and respiratory diseases in children and adults. NTHi bacteria are one of the major causes of respiratory tract infections, including acute otitis media, cystic fibrosis, and community-acquired pneumonia among children, especially in developing countries. The bacteria can also cause chronic diseases such as chronic bronchitis and chronic obstructive pulmonary disease in the lower respiratory tract of adults. Such bacteria express several outer membrane proteins, some of which have been studied as candidates for vaccine development. Due to the lack of effective vaccines as well as the spread and prevalence of NTHi worldwide, there is an urgent need to design and develop effective vaccine candidates against these strains.
