Pathogenicity of Pasteurella pneumotropica in Immunodeficient NOD/ShiJic-scid/Jcl and Immunocompetent Crlj:CD1 (ICR) Mice

Abstract

Abstract:Pasteurella pneumotropica is an opportunistic pathogen in rodents. Natural infection in immunodeficient animals suggests that immunodeficiency is a major factor in P. pneumotropica pathogenesis. To understand this process, we performed clinical, pathological and bacteriological studies of immunodeficient NOD/ShiJic-scid/Jcl and immunocompetent Crlj:CD1 (ICR) mice experimentally infected with P. pneumotropica ATCC 35149. From 14 days postinoculation, some of P. pneumotropica-infected NOD/ShiJic-scid/Jcl mice developed clinical signs of weight loss. Three of 10 P. pneumotropica-infected NOD/ShiJic-scid/Jcl mice developed clinical signs of depression, ruffled coat, and weight loss and died at 27, 34, and 59 days postinoculation. At 35 days postinoculation, almost all P. pneumotropica-infected NOD/ShiJic-scid/Jcl mice had lung abscesses. The bacteria were isolated from the upper and lower respiratory tracts, including the lungs, and blood. In contrast, P. pneumotropicainfected ICR mice exhibited no clinical signs or lesions. The bacteria were isolated from the upper, but not the lower respiratory tracts. We developed an animal model for understanding host interactions with P. pneumotropica.

Experimental Contact Infection of NOD/ShiJic-scid Mice with Pasteurella pneumotropica

“…This result is in agreement with that of our previous study [7]. Similarly, upon contact infection, the lesions were similar to those of intranasal inoculation.…”

“…This difference could be based on dispersion volumes of intranasal inoculation. The death rates of intranasal inoculation agreed with those of our previous study [7]. The results reinforced the results of a previous study of NOD/ShiJic-scid mice inoculated with P. pneumotropica strain ATCC 35149, which reported death rates of 25%.…”

“…There have been some studies on the transmission of this species; however, to our knowledge, experimental contact infection of P. pneumotropica has not been reported [15,16]. In our previous study, NOD/shiJicscid/Jcl mice with multiple defects in adaptive and non-adaptive immunological functions were intranasally infected with bacteria [7]. Herein, some mice displayed lung abscesses and died.…”

“…In immunocompetent animals, clinical diseases are not commonly observed. However, immunodeficient animals develop mild to severe or lethal diseases [5][6][7][8][9][10].…”

Intranasal immunization with a non-adjuvanted adhesive protein descended from Pasteurella pneumotropica and its preventive efficacy against opportunistic infection in mice

“…Pasteurella pneumotropica is the causative agent of rodent pasteurellosis [14]. In current studies, several RTX (repeats in toxin) toxins were identified in this species, and of these, 250-kDa PnxI-IIA contains bacterial Ig-like domains and hemagglutinin repeats that are thought to be indispensable for the protein's attachment and invasion of bacterial cells into host organs [15,16].…”