Host and bacterial factors control theMycobacterium avium-induced chronic peritoneal granulocytosis in mice

Abstract

SUMMARY: Persistent peritoneal granulocytosis and elevated macrophage counts have been found in nine mouse strains from 8 to 90 days after infection with Mycobacterium avium. Peritoneal granulocylosis was higher in M. avium-resistant BALB/c. Bcgr (C.D2) mice, compared with congenic M. avium-susceptible BALB/c (Bcgb) animals. Although maximal granulocytosis values were not related to virulence of the inocula, the kinetics of the granulocytic response varied with the virulence of M. arium. Following infections by avirulent (rough) strains of M. avium, the peritoneal granulocytosis progressively declined in BALB/c and C3H/He mice. A similar decline in granulocyte number was observed in resistant C3H/He mice infected with virulent M. avium (smooth transparent strain). In both instances the decline in the peritoneal granulocytosis was associated with a progressive elimination of the inoculum. In the susceptible BALB/c mice, virulent M. avium strains induced progressive infection accompanied with a rapid decline in granulocyte number, whereas the infection with attenuated M. avium, which caused a chronic infection, induced persistent granulocytosis. The ability to recruit granulocytes following the intraperitoneal inoculation of a phlogistic substance (casein hydrolysate) was decreased in infected susceptible but not in infected resistant mice at 90 days of infection with virulent M. avium.