ABSTRACT
The aim of this study was to investigate the effects of ajowan essential oil (AjEO)/thymol and antibiotics combinations against three standard strains and six resistant clinical isolates of major respiratory bacteria (Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae). The broth microdilution method was conducted to determine the minimum inhibitory concentrations (MIC) of essential oil/thymol and antibiotics. The checkerboard method was used to investigate the interactions between the essential oil/thymol and antibiotics by means of the fractional inhibitory concentration index (FICI). The chemical composition of essential oil was also analysed by GC-MS and GC-FID. Thymol (50·75%), γ-terpinene (25·94%) and p-cymene (18·31%) were identified as major constituents of the oil. The most sensitive organisms to ajowan volatile oil were Strep. pneumoniae bacteria (MIC = 0·125-0·5 mg ml-1 ). Synergistic effects were observed with AjEO/thymol and amoxicillin combinations on methicillin-resistant Staph. aureus clinical isolates (FICI = 0·37-0·50) and with essential oil and ciprofloxacin combinations against P. aeruginosa ATCC 27853, Staph. aureus ATCC 25923 and penicillin (P)-resistant Strep. pneumoniae bacteria (FICI = 0·37-0·50). Combination of thymol and ciprofloxacin produces synergistic effects only against P. aeruginosa ATCC 27853 and P-resistant Strep. pneumoniae clinical isolate (FICI = 0·46-0·49).
Subject(s)
Anti-Bacterial Agents/pharmacology , Carum/chemistry , Ciprofloxacin/pharmacology , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Pseudomonas aeruginosa/drug effects , Respiratory Tract Infections/drug therapy , Staphylococcus aureus/drug effects , Streptococcus pneumoniae/drug effects , Thymol/pharmacology , Ammi/chemistry , Cyclohexane Monoterpenes , Cymenes , Drug Resistance, Multiple, Bacterial/drug effects , Drug Therapy, Combination , Humans , Microbial Sensitivity Tests , Monoterpenes/pharmacology , Pseudomonas aeruginosa/isolation & purification , Respiratory System/microbiology , Respiratory Tract Infections/microbiology , Spices/analysis , Staphylococcus aureus/isolation & purification , Streptococcus pneumoniae/isolation & purificationABSTRACT
BACKGROUND: Culture is needed to confirm tuberculosis but results are generally obtained after several weeks. OBJECTIVES: We compared a direct microscopic observation technique for detection of mycobacterial culture positivity (MODS) with the classic solid and MB/BacT cultures in terms of sensitivity, contamination rate, speed and cost on 488 samples. RESULTS: The sensitivity of the MODS technique--99,2% (162 positive samples) was higher than MB/BacT 78,4% (125 positive samples) and solid culture 69,6% (113 positive samples) P<0.005 for all comparisons. The median times to positivity were 21, 13.3 and 3 days on solid media, B/BacT and MODS respectively. CONCLUSIONS: The MODS technique is faster and more sensitive than both solid media and MB/BacT culture.
