LETHALITY FOR MICE AND CHICK EMBRYOS, PYROGENICITY IN RABBITS AND ABILITY TO GELATE LYSATE FROM AMOEBOCYTES OF LIMULUS POLYPHEMUS BY LIPOPOLYSACCHARIDES FROM BACTEROIDES, FUSOBACTERIUM AND VEILLONELLA

Abstract

Phenol‐water extracted lipopolysaccharides (LPS) from Veillonella, Fusobacterium nucleatum, Bacteroides fragilis and Bacteroides melaninogenicus were lethal for mice and 11‐days‐old chick embryos, pyrogenic in rabbits, and gelated Limulus amoebocyte lysate. Mouse lethality was considerably enhanced by actinomycin‐D. In all test systems the endotoxin activity of Veillonella and Fusobacterium LPS was comparable to that of LPS from Salmonella enteritidis, which was included as a reference endotoxin. The endotoxicity of the Bacteroides LPS was very low. While nanograms of the Veillonella and Fusobacterium LPS killed the chick embryos and gelated the Limulus lysates, microgram amounts of the Bacteroides LPS were needed to give positive reaction in the same test systems. As much as 74 μg of the most active B. fragilis LPS were required to give a typical biphasic fever response in rabbits. A significant correlation was found between all test results (r = 0.90‐0.98, p < 0.001).

CHEMICAL COMPOSITION AND BIOLOGICAL PROPERTIES OF A LIPOPOLYSACCHARIDE FROM BACTEROIDES INTERMEDIUS

“…In some bacterial groups LPS may have an additional chain (O-antigen) consisting of repeating sugar units (31). LPS from Bacreroidrs species apparently have an atypical structure, manifested by lack of KDO and heptose in the core region, a different lipid A composition (7,8,9,31), and an endotoxic potency considerably lower than that of enterobacterial LPS (20,28). This general picture is confirmed in several recent reports on Bacteroides fragilis LPS and Bacteroides gingivalis LPS ( 14,16,17,22,30).…”

“…The low biological activity of the B. intertnedius LPS confirms previous observations on other Bactcroides LPS in several systems, including the Limulus amebocyte lysate assay (17, 24. 28), the Shwartzman reaction (24) and the lethality of mice (24,28) and chick embryos (28). Endotoxic activity of the B. intermedius LPS was demonstrated by activating the clotting cascade of the limulus amebocyte (26); as expected, high doses (7.0 ng/ml) were needed compared to the E. coli 055 LPS (0.7 ng/ml) (28).…”

“…28), the Shwartzman reaction (24) and the lethality of mice (24,28) and chick embryos (28). Endotoxic activity of the B. intermedius LPS was demonstrated by activating the clotting cascade of the limulus amebocyte (26); as expected, high doses (7.0 ng/ml) were needed compared to the E. coli 055 LPS (0.7 ng/ml) (28). The negative Shwartzman reaction with B. intermrdius LPS may reflect a lipid A structurally different from that of E. coli LPS.…”

Host Response to Translocated Microbial Products Predicts Outcomes of Patients With HBV or HCV Infection

“…The association of sCD14 with disease progression is similar to observations in HIV/HCV co-infected patients, in whom increased sCD14 and LPS levels were associated with the development of cirrhosis 34 . The detection of LPS can be complicated by its rapid clearance and by inhibitory plasma proteins 11,35–38 , and not all bacteria produce bioactive LPS or LPS detectable by the Limulus assay 39–41 . Thus, sCD14 may be a more relevant biomarker of disease progression as it reflects the host response to products of microbial translocation.…”

TOXIC EFFECTS OF LIPOPOLYSACCHARIDE FROM BACTEROIDES INTERMEDIUS AND ESCHERICHIA COLI ASSESSED IN THE PRE‐IMPLANTATION MOUSE EMBRYO CULTURE SYSTEM

“…A previous study (2) demonstrated that B. intermedius was 8-10 fold less toxic (chick embryo LDSo, Limulus gelation test) than E. coli LPS and gave negative response in the Shwartzman reaction; however, in these biological tests the lethal or toxic effects are mediated by the complement system, the reticuloendothelial system, and by immune reactions (8,16). The present results thus indicate that when the toxic LPS effects (2,16) were isolated from the immunopotentiating effects (5,7) as in the pre-implantation embryo system, the E. coli LPS was only slightly more toxic than B. intermedius LPS, and the differences were much smaller than in other complex biological systems (2, 5, 21).…”