Anti-quorum sensing activity of substances isolated from wild berry associated bacteria

Background: Quorum Sensing [QS] is a mechanism used by bacteria to determine their physiological activities and coordinate gene expression based on cell to cell signaling. Many bacterial physiological functions are under the regulation of quorum sensing such as virulence, luminescence, motility, sporulation and biofilm formation. The aim of the present study was to isolate and characterize Quorum Sensing Inhibitory [QSI] substances from epiphytic bacteria residing on wild berries surfaces

Methods: Fifty nine bacterial isolates out of 600 screened bacteria were successfully isolated. These bacteria were obtained from berry surfaces of different plants in the wild forests of Ajloun-Jordan. Screening for QSI activity using Chromobacterium violaceum ATCC 12472 monitor strain, resulted in isolating 6 isolates exhibiting QSI activity only, 11 isolates with QSI and antibacterial activity, and 42 isolates with antibacterial activity only. Three potential isolates S 130, S 153, and S 664, were gram positive rods and spore formers, catalase positive and oxidase negative. These were chosen for further testing and characterization

Results: Different solvent extraction of the QSI substances based on polarity indicated that the activity of S 130 was in the butanol extract, S 153 activity in both chloroform and butanol; and for S 664, the activity was detected in the hexane extract. The chloroform extract of S 153 and hexane extract of S 664 were proteinaceous in nature while QSI substances of the butanol extract of S 130 and S 153 were non-proteinaceous. All the tested QSI substances showed a marked thermal stability when subjected at several time intervals to 70[degree]C, with the highest stability observed for the butanol extract of S 153. Assessing the QSI substances using violacein quantification assay revealed varying degrees of activity depending upon the extracting solvent, type of the producer bacteria and the concentration of the substances

Conclusion: This study highlighted the potential of untapped reservoirs in nature to be used as a source of unique metabolite that may be further developed for therapy. The potential QSI substances included in this study are just one aspect to be further analyzed for use as biopharmaceutical agents

Probiotics: the forth coming oral health alternative therapy

Probiotics, live cells having various health-promoting effects and benefits to the host, have been, and still are, under extensive investigations. These "friendly microorganisms" are usually isolated from the human intestine and traditionally-fermented foods of plant and animal origin. They are recognized for their positive effects on the intestinal flora among many other direct and indirect benefits eliciting better human body functioning. Studies are being conducted in the last decade o substantiate the real role played by these exotic microorganisms and to ascertain the safety of its use being of probiotic potential. The concept of disease prevention, rather than treatment, is most appealing to health providers and clinical settings world-wide. Dentistry is not an exception; preventive oral medicine is a significant pillar in modern dental practices. In fact, a large proportion of every day dental care, in addition to clinical treatments, aims at preventing oral diseases, including caries, gingivitis, periodontitis and halitosis. Based on varying results of so many clinical trials using different types and formulas of experimental oral probiotics and to shed some light on the questionable role and effectiveness of probiotics on the prevention and treatment of oral diseases, this mini review is presented. We believe that exploring the possible mechanisms of action of probiotic bacteria in the oral cavity and identifying specific potential uses of probiotics in preventive dentistry and stomatology is eminent and needs further investigations pertaining to developing a safe, efficient and reliable general and perhaps designer oral probiotics

Microbial contamination of ice cream in the city of Amman

Thirty seven ice cream samples collected from restaurants, supermarkets, and retail shops in Amman were examined to determine the numbers and types of bacteria and yeasts present at the time of purchase. Coliforms, including Escherichia coli, staphylococci, and suspected shigellae and salmonellae were present in 32 of the examined samples in numbers exceeding accepted international standards. Storage of the ice cream before distribution resulted in a significant decrease in microbial counts. The decrease attained after 24 hours of freeze-storage was 50% in coliforms, 24% in staphylococci, and about 90% in total counts. After five days of storage all counts were less than 5% of the original, except for staphylococci. Results indicate that strict hygienic controls should be imposed on processing of ice cream in the city of Amman