TY - JOUR
T1 - Resistance of Klebsiella pneumoniae to the innate immune system of African green monkeys
AU - Cox, Brandi L.
AU - Schiffer, Holly
AU - Dagget, Gregory
AU - Beierschmitt, Amy
AU - Sithole, Fortune
AU - Lee, Elise
AU - Revan, Floyd
AU - Halliday-Simmonds, Iona
AU - Beeler-Marfisi, Janet
AU - Palmour, Roberta
AU - Soto Martinez, Esteban
PY - 2015/3/23
Y1 - 2015/3/23
N2 - In recent years, an emergent Klebsiella pneumoniae hypermucoviscosity (HMV) phenotype has been associated with increased invasiveness and pathogenicity in primates. In this project, bacteria recovered from infected African green monkeys (AGM) (Chlorocebus aethiops sabaeus) were screened for HMV phenotype, and were compared to non-HMV isolates in in vitro, serum, and oxidative-mediated killing assays. Complement-mediated killing was assessed utilizing freshly collected serum from healthy AGM. Oxidative-mediated killing was investigated utilizing sodium hypochlorite and hydrogen peroxide. Compared to non-HMV isolates, HMV isolates were more resistant to serum-mediated and oxidative killing (p<. 0.05). Phagocytosis resistance was evaluated using AGM peripheral blood monocytes (PBMC), and results indicated that non-HMV isolates associated with the AGM PBMC to a greater extent than HMV isolates (p<. 0.001). Measurement of lactate dehydrogenase release showed that HMV isolates were more cytotoxic to AGM PBMC than non-HMV isolates (p<. 0.001). Thus, the hypermucoid phenotype appears to be an important virulence factor that promotes evasion of innate immune defenses.
AB - In recent years, an emergent Klebsiella pneumoniae hypermucoviscosity (HMV) phenotype has been associated with increased invasiveness and pathogenicity in primates. In this project, bacteria recovered from infected African green monkeys (AGM) (Chlorocebus aethiops sabaeus) were screened for HMV phenotype, and were compared to non-HMV isolates in in vitro, serum, and oxidative-mediated killing assays. Complement-mediated killing was assessed utilizing freshly collected serum from healthy AGM. Oxidative-mediated killing was investigated utilizing sodium hypochlorite and hydrogen peroxide. Compared to non-HMV isolates, HMV isolates were more resistant to serum-mediated and oxidative killing (p<. 0.05). Phagocytosis resistance was evaluated using AGM peripheral blood monocytes (PBMC), and results indicated that non-HMV isolates associated with the AGM PBMC to a greater extent than HMV isolates (p<. 0.001). Measurement of lactate dehydrogenase release showed that HMV isolates were more cytotoxic to AGM PBMC than non-HMV isolates (p<. 0.001). Thus, the hypermucoid phenotype appears to be an important virulence factor that promotes evasion of innate immune defenses.
KW - Cytotoxicity
KW - Hypermucoviscosity
KW - Oxidative killing
KW - Phagocytosis
KW - Serum resistance
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U2 - 10.1016/j.vetmic.2015.01.001
DO - 10.1016/j.vetmic.2015.01.001
M3 - Article
C2 - 25614101
AN - SCOPUS:84922838136
VL - 176
SP - 134
EP - 142
JO - Veterinary Microbiology
JF - Veterinary Microbiology
SN - 0378-1135
IS - 1-2
ER -