Phytochemical and biological activities of Bituminaria bituminosa L. (Fabaceae).

OBJECTIVE: To investigate the phytochemical composition, the antioxidant and antibacterial activities of Bituminaria bituminosa L. (Fabaceae) (B. bituminosa). METHODS: The aerial parts of B. bituminosa yielded two compounds. The structures of these compounds were determinated using UV, (1)H-NMR and (13)C-NMR experiments and comparison of their spectroscopic properties with literature data. The antibacterial activity of the extracts (CH2Cl2, ethyl acetate and n-BuOH) was determinated using disk diffusion method against standard and clinical strains. Antioxidant potential of n-BuOH extract was evaluated through two methods: DPPH and cupric ion reducing antioxidant capacity assay. RESULTS: The n-BuOH extract from B. bituminosa yielded the isolation of isoflavone and flavone. The extracts CH2Cl2, ethyl acetate and n-BuOH demonstrated significant antibacterial activities. CH2Cl2 extract showed the maximum antibacterial activity with high concentration of 2 mg/mL against Staphylococcus aureus ATCC 29213, Klebsiella pneumonia and Escherichia coli ATCC 25922 (20.45 mm, 16.41 mm and 15.74 mm inhibition zone, respectively). The value IC50 was 0.26 µg/mL for n-BuOH extract using DPPH method. Whereas the E% value was 0.10 L/mg every centimeter for cupric ion reducing antioxidant capacity assay. CONCLUSIONS: The phytochemical study of B. bituminosa revealed the presence of isoflavone (daidzin) and flavone (isoorientin) and identified for the first time in this specie. The antibacterial activity of the plant B. bituminosa is certainly related to its chemical content. The n-BuOH extract showed a significant antioxidant activity.

Synthesis, crystal structure and antibacterial activity of new highly functionalized ionic compounds based on the imidazole nucleus.

Several new highly functionalized imidazolium derivatives were synthesized, via appropriate synthetic routes, using imidazole, 1-methylimidazole and 2-phenyl-1-methylimidazole as key intermediates. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella thipymurium using disk-diffusion and MIC methods. Crystal X-ray structures are reported for six compounds.

Outbreak of Salmonella enterica serotype Infantis producing ArmA 16S RNA methylase and CTX-M-15 extended-spectrum ß-lactamase in a neonatology ward in Constantine, Algeria.

Plasmid-mediated 16S rRNA methylases such as ArmA, which confer high levels of resistance to aminoglycosides, are increasingly reported in Enterobacteriaceae. This study investigated the molecular mechanism of ß-lactam and aminoglycoside resistance in extended-spectrum ß-lactamase (ESBL)-producing Salmonella enterica serotype Infantis isolated at the 53-bed neonatology ward of University Hospital Benabib in Constantine, Algeria. From September 2008 to January 2009, 200 S. enterica isolates were obtained from 138 patients (age range 8-80 months) hospitalised in the neonatology ward. Most isolates were from stool cultures, but also from two blood cultures and one gastric fluid. The isolates were multidrug-resistant and produced TEM-1 and CTX-M-15 enzymes as well as the 16S RNA methylase ArmA. The armA, bla(CTX-M-15) and bla(TEM-1) genes were located on the same 140-kb self-transferable plasmid belonging to the IncL/M incompatibility group. All of the S. Infantis isolates belonged to a single clone. Increased infection control measures and thorough biodecontamination of the rooms led to control of the outbreak but did not eradicate the epidemic strain. This study further illustrates the global emergence of ArmA methylase and its frequent association with bla(CTX-M) genes. Spread of 16S RNA methylase determinants at the same level as bla(CTX-M) genes in Enterobacteriaceae may seriously compromise the efficacy of aminoglycosides for treating Gram-negative infections.

MALDI-TOF-MS for rapid detection of staphylococcal Panton-Valentine leukocidin.

Toxin-producing gram-positive bacteria are responsible for emerging and life-threatening infections in humans worldwide. Both rapid toxin detection and adapted therapy are essential to limit the morbidity due to such toxins, especially staphylococcal Panton-Valentine leukocidin (PVL). Here we describe the use of a mass spectrometry profile generated by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) followed by ClinProTools 2.0 software analysis to find a reproducible model able to identify PVL in Staphylococcus aureus strains. Eighty-one S. aureus strains were used and tested for the presence of PVL, toxic shock syndrome toxin (TSST-1) and mecA genes. The peak at 4448 mass-to-charge ratio (m/z) was the most relevant peak to differentiate between PVL-producing and non-PVL-producing S. aureus. A model using only this peak had an overall recognition capability of 100% and an overall cross-validation of 77.07%. Prospective evaluation of the model allowed two cases of PVL-producing strains to be detected within a few minutes during the time of care and before polymerase chain reaction (PCR) results. Our study represents a proof of concept for the use of such rapid technology as a point-of-care method to identify potential lethal toxin quickly. We believe that such a rapid method will be timely to help change the therapeutic strategy and could be used in the future for other pathogens and infectious diseases.