The Preventive Effects Of Intestinal Barrier On Enterogenic Breakthrough Invasive Candida Infection

Objective:Prove that broad-spectrum antibiotics and (or) stress state can cause intestin al flora disturbance, and make the normal flora of bacteria (e.g., candida albic ans) which should be of smallamount and the passing flora multiply largely. Pr ove that the intestinal barrier can provide protection during invasive fungal dise ase in the stress state, and the immunologic function may play an important ro le.Methods:This research is an animal experiment,and the experimental subject is Wistar rat. Divide60rats(regardless of male and female) into3groups, there are20rats per group. The first group is the blank control group; The second group is antibiotics group,and the ratsare intravenous injected ceftriaxone(100mg/kg) once a day; The third group is antibiotics+acute pancreatitis(AP) group,the ratsaregiven20%L-ARG intraperitoneal injection(1.25mg/kg) twice with the interval of one hour to cause acute hemorrhagic pancreatitis model,meanwhile this group is also given ceftriaxone, the dose is the same with the second group. All the three groups are provided the same food, water and living condition.On the7th day and the14th of the research, we take10rats of each group, divide the cervical vertebra, and get the samples rapidly under aseptic condition. The samples include intracardiac blood, portal venous blood, intestinal content, intestinal wall and mesenteric lymph nodes.Send blood,tissue homogenate and intestinal contents for fungal culture,and do microscopic examination for the bowel wall tissue and pancreatic pathological section.If more than one samplesfrom one rat culturepositive, separate the fungi, and make the identification in the level of isolation with the18S rDNA-ITS sequence analysis technology to make sure whetherthe fungi are breakthrough.Results:1. In the7th day of the research, the intestinal content culture results of the antibiotics group and antibiotics+AP group are significantly different from the blank control group. It implies that there are already intestinal flora disturbance in the7th day, and the fungi have already multiplied.2. In the14th day of the research, the intestinal content culture results of the antibiotics group and antibiotics+AP group are significantly different from the blank control group. It implies that there are stillintestinal flora disturbance in the14th day, and the fungi multiply.3.No matterin the7th day of the research or in the14th day, there are no statistical differences between intestinal content culture results of the antibiotics group and the ones of the antibiotics+AP group. It suggests that acute stress may not aggravate the intestinal flora disturbance on the base of long time antibiotics use.4. In both the7th day and the14th day of the research, there are no evidences of intestinal barrier breakthrough in the antibiotics group and antibiotics+AP group compared with the blank control group, so no invasive fungal disease happened.5.The immunologicfunction of Intestinal Barrier may play an important role in preventing from invasive fungal disease.Conclusions:Long time use of broad-spectrum antibiotics can cause intestinal flora disturbance and fungi proliferation, and as the time of antibiotics use grows, intestinal flora disturbance may not be aggravated, even there is stress factor; When the fungi become the dominant bacterial community, Intestinal barrier still can provide protection even acute stress exists,So the fungi can’t go through the Intestinal barrier to cause IFD. It implies that the immunologicfunction of intestinal barrier may play an important role.