Honey exhibits antimicrobial activities against a wide range of bacteria in different milieu. This study aims to compare the effects of five types of honey (both imported and local Saudi honey) against . The five types of honey (Manuka Honey UMF +20, Manuka Honey UMF +16, Active +10 Manuka Honey, Sidr honey and honey) were evaluated for their bactericidal/bacteriostatic activities against both methicillin resistant and sensitive . The inhibitory effect of honey on bacterial growth was evident at concentrations of 20% and 10% (v/v). Manuka Honey showed the best results. Manuka Honey UMF +20 had a bactericidal effect on both methicillin resistant and sensitive. However, Sidr and honey exerted only a bacteriostatic effect. The efficacy of different types of honey against was dependent on the type of honey and the concentration at which it was administered. Manuka Honey had the best bactericidal activity. Future experiments should be conducted to evaluate the effects of honey on bacterial resistance.

The results indicated that various types of honey affected the test organisms differently. Modulation of antimicrobial resistance was seen in the case Manuka honey UMF +10.

Staphylococcus aureus is a major human pathogen, where the emergence of antibiotic resistant strains is making all types of S. aureus infections more challenging to treat. With a pressing need to develop alternative control strategies to use alongside or in place of conventional antibiotics, one approach is the targeting of established virulence factors. However, attempts at this have had little success to date, suggesting that we need to better understand how this pathogen causes disease if effective targets are to be identified. To address this, using a functional genomics approach we have identified a small membrane bound protein that we have called MspA. Inactivation of this protein results in the loss of the ability of S. aureus to secrete cytolytic toxins, protect itself from several aspects of the human innate immune system and control its iron homeostasis. These changes appear to be mediated though a change in the stability of the bacterial membrane as a consequence of iron toxicity. These pleiotropic effects on the ability of the pathogen to interact with its host result in a significant impairment in the ability of S. aureus to cause infection in both a subcutaneous and sepsis model of infection. Given the scale of the effect the inactivation of MspA causes, it represents a unique and promising target for the development of a novel therapeutic approach.

Staphylococcus aureus produces a plethora of virulence factors critical to its ability to establish an infection and cause disease. We have previously characterised a small membrane protein, MspA, which has pleiotropic affects on virulence and contributes to S. aureus pathogenicity in vivo. Here we report that mspA inactivation triggers overaccumulation of the essential cell wall component lipoteichoic acid (LTA) which, in turn, decreases autolytic activity and leads to increased cell size due to a delay in cell separation. We show that MspA directly interacts with the LTA synthesis enzymes UgtP, LtaA and LtaS, and competitively interferes with the association between LtaA and LtaS. While complementation of the mspA mutant with wild-type mspA reduces the amount of LTA, expression of a mutated version of MspA that does not interfere with the interactions between LtaA and LtaS does not. We suggest that MspA contributes to maintaining a physiological level of LTA in the cell wall by interacting with the LTA synthetic enzymes. In conclusion, this study uncovers the critical role of the MspA protein in regulating cell envelope biosynthesis and pathogenicity.