Efficacy Evaluation Of Egg Yolk Immonoglobulins (IgYs) Against Solobacterium Moorei Causing Halitosis

Halitosis is a kind of disease afftects normal social activities. It is demonstrated that halitosis is caused by the catabolism of bacteria in our mouth. Solobacterium moorei (S. moorei) is a gram-positive, anaerobic, non-spore-forming bacillus, which was first isolated from human feces in the year 2000. It has been reported that S. moorei has a causative relationship with oral halitosis. The objective of this study was to estimate the in vitro and vivo effectiveness of chicken egg yolk antibody (IgY) in the control of S. moorei.Intact S. moorei cells were used as an immunogen to immunize four White Leghorn hens. IgY extracted from egg yolks obtained from these immunized laying hens was purified using water dilution, two-step salt precipitation and ultra-filtration and a final purification of 87.3% was obtained. The IgY antibody titer determined by Enzyme-Linked Immunosorbent Assay (ELISA) was dramatically increased after the third immunization and peaked at 10,000. Specific IgY had weak cross reaction with Prevotella intermedia, Porphyromonas gingivalis and Fusobacterium nucleatum, which demonstrated the strong specificity of IgY.The growth of S. moorei in liquid media, measured every 12 h using a microplate reader at 600 nm, was significantly (P<0.05) inhibited by specific IgY at 20 and 40 mg/ml compared with the control. Biofilm formation by S. moorei was quantified by staining with crystal violet and was inhibited by specific IgY. The specific binding ability of IgY was further confirmed by the use of immunofluorescence and immunoelectron microscopy.The mice were challenged with S. moorei in the concentration of 109 CFU/ml for a week. 40 mg/ml specific IgY (disolved in 2% carboxymethyl cellulose) was oral administrated.5 weeks later, blood serum was obtained to evaluate the level of Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-PX), Malondialdehyde (MDA), lysozyme in different treatments. The group treated with specific IgY exhibited higher level of SOD, GSH-PX and lysozyme but lower content of MDA compared with the negative group, which demonstrated that specific IgY can release the inflammatory reaction. The number of total colonies and black colonies in different period was measured by cultivation on different culture media. The number of total colonies and black colonies was extremely decreased by the addition of specific IgY (P<0.05).In conclusion, this study demonstrated that the growth and biofilm formation of S. moorei can be effectively inhibited by specific IgY in vitro. Oral administration of IgY can effectively release the inflammatory reaction and inhibite the growth of anaerobic bacteria and S. moorei. As a result, IgY technology may have application in the control of oral halitosis caused by S. moorei.