The dynamics of experimental bacterial infections in muscles of mice and the influence of hog gastric mucin.
NMRI-mice were infected in the posterior of the thigh muscles of the right hind leg by injecting one of two isogenic strains of E. coli, one of which was passaged from mouse to mouse for 20 years [mouse-pathogenic (MP) strain], whereas the other was transferred on agar slants only for the same period of time (lab strain). Both strains cause persistent infections only if given as undiluted overnight culture, the MP-strain seeming slightly more virulent. Injection of lower numbers of bacteria results in a corresponding decrease of bacterial cell counts in the animals' thighs. The elimination of the bacteria seems to be all the more rapid the smaller the inoculum. If the infection was administered in mucin suspension, the MP-strain multiplies in the host tissue to a greater degree than the lab strain, irrespectively of the dose injected. The number of cells per muscle reaches a maximum level of about 10(9) even after injecting 10(2) cells of the MP-strain in mucin. To reach the same level, 10(5) cells of the lab strain are needed. Four days after infection, the bacteria start to die off in those animals originally receiving the lower infection doses. Possible reasons are discussed.
D000818:Animals; D004926:Escherichia coli / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D005752:Gastric Mucins / Q000494:pharmacology*; D007700:Kinetics; D051379:Mice; D013552:Swine; D013848:Thigh; D014774:Virulence / Q000187:drug effects*
D005752:Gastric Mucins