Shifts in the immunocompetence of lymphoid tissue in guinea pigs containing a limited microflora.
Many authors have demonstrated simplification of the species composition of the normal microflora in animals long kept in a closed environment. The purpose of the present work is to reveal the effect of such simplification (without reduction of the total number of bacteria) on the immunocompetent system of the animals. Three months old germ-free, monocontaminated (Staph. albus) and conventional guinea pigs with reduced fecal microflora were used in this study. Guinea pigs of the second group were fed a sterile diet but were kept in an ordinary vivarium. Two groups of control animals were: 1) conventionals fed regular diets; 2) conventionals fed the diet contaminated with fecal microflora of guinea pigs after sterilization. The fecal microflora was examined. The total number of bacteria in faeces of monocontaminated and microflora-reduced conventional animals was approximately the same as in conventional controls. Various lymphoid organs were examined. Their weight, size, number and activity of germinal centres, amount of globulin-producing cells, their differentiation and amount of globulins in single cells were determined. The lymphoid tissue in microflora-reduced animals and especially in monocontaminated guinea pigs was found to be underdeveloped. These changes were, however, less pronounced than in germ-free animals. It is suggested that simplification of the microflora in a macro-organism during long-term enclosure reduces the lymphoid tissue; such a macro-organism may develop severe reactions of the microbial shock, when occurring in a normal microbial environment.
Gamaleya Institute for Epidemiology and Microbiology of the Academy of Medical Sciences, Moscow, USSR.
K A
KA
Lebedev
O V
OV
Chakhava
D000818:Animals; D004032:Diet; D005243:Feces / Q000382:microbiology*; D005516:Food Microbiology; D005856:Germ-Free Life / Q000276:immunology* / Q000502:physiology; D006168:Guinea Pigs; D007121:Immunocompetence / Q000276:immunology / Q000502:physiology*; D007422:Intestines / Q000382:microbiology; D008198:Lymph Nodes / Q000033:anatomy & histology / Q000276:immunology* / Q000502:physiology; D008221:Lymphoid Tissue / Q000276:immunology / Q000502:physiology*; D009929:Organ Size; D013210:Staphylococcus / Q000276:immunology