title: Endotoxin liberation from Neisseria meningitidis isolated from carriers and clinical cases.
abstract: Endotoxin liberation was studied in a blinded material of 121 Neisseria meningitidis isolates; from nasopharynx of 58 carriers and from cerebrospinal fluid or blood of 63 cases with meningococcal disease. Endotoxin activity in culture filtrates was determined by a Limulus lysate test. Meningococci isolated from clinical cases were significantly more frequently endotoxin-liberating (E+) (84.1%) than in carriers (25.9%); p less than 0.001. Serogroupable carrier isolates had a significantly higher frequency of E+ meningococci (61.9%) than non-groupable ones (5.4%); p less than 0.002. Serogroup B case isolates, which generally had a larger amount of capsular polysaccharide than B meningococci from carriers, had a significantly higher proportion of E+ meningococci than group B from carriers; p = 0.007. All 7 serogroup C isolates were E+ (5 cases and 2 carriers). No correlation was found between endotoxin liberation and the serotype: subtype 15:P1.16, tested by a selection of monoclonal antibodies, or between endotoxin liberation and sulfonamide resistance, when carrier and case isolates were studied separately. Meningococci isolated from cases had the following mean endotoxin titres: 320.5 in the meningitis group, 408.2 in the septicaemic group, 462.1 in the septicaemic and meningitis group, and 123.7 in the group with other systemic disease. E+ meningococci were isolated from 5/6 fatal cases. Thus, endotoxin liberation from meningococci is strongly, but not completely associated with establishment of meningococcal disease and with the presence of capsular polysaccharide.
mesh_terms: D002353:Carrier State / Q000382:microbiology*; D002555:Cerebrospinal Fluid / Q000382:microbiology; D004731:Endotoxins / Q000378:metabolism*; D006801:Humans; D008585:Meningitis, Meningococcal / Q000382:microbiology*; D008589:Meningococcal Infections / Q000382:microbiology*; D009305:Nasopharynx / Q000382:microbiology; D009345:Neisseria meningitidis / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D018805:Sepsis / Q000382:microbiology; D012703:Serotyping; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D004731:Endotoxins; D013449:Sulfonamides