Cinnamaldehyde increases the susceptibility of quorum-sensing-mediated biofilms to conventional antibiotics

The role of bacterial communication, also known as quorum sensing is an important mechanism in biofilm formation which is fundamental to the development of anti-biofilm strategies. In this current study, the synergy between a quorum sensing inhibitor (cinnamaldehyde) and two antibiotics (ceftazidime and levofloxacin) was evaluated in an attempt to develop a strategy for biofilm disruption using the high-throughput minimum biofilm eliminating concentration (MBEC) assay. Klebsiella pneumoniae and Proteus mirabilis biofilms of initial broth suspensions of 108 colony forming units (CFU) per mL, cultivated on the pegs of the MBEC device were challenged with 5120 µg/ml of ceftazidime and levofloxacin in a double dilution assay in the presence of 500 µM cinnamaldehyde. The minimum inhibitory concentrations (MIC) in the presence of cinnamaldehyde for ceftazidime and levofloxacin were 0.125% (640 µg/mL) and 0.0625% (320 µg/mL) respectively with no significant bacterial growth on LB agar. The MBECs for ceftazidime and levofloxacin were above 5120 and 2560 µg/mL respectively which yielded over 70% reduction in both Klebsiella pneumoniae and Proteus mirabilis biofilms. The above results indicate the possibility that the synergy between antimicrobial agents may lead to biofilm eradication.

A Mixed Blessing: Market-mediated Religious Authority in Neopaganism

This is a study of the interplay of market-mediated and religious authority in the context of new religious movements. Specifically, we explore the ambivalent relationship followers of Wicca have with the marketplace. Our main argument is that in this context marketplace success can be a source of religious legitimacy and validation. At the same time, however, excessive engagement with the market can act as a powerful delegitimizing mechanism, leading religious leaders to continually monitor their practices. Market success is thus a mixed blessing that can increase religious authority and influence, but is just as likely to decrease authority and credibility. Based on an ethnographic study, we explore the boundary work carried out by religious marketers and consumers in order to establish themselves in a “safety area” where engagement with the market brings its positive effects without causing a loss of credibility.