Bactericidal and Opsonic Activity against Neisseria gonorrhoeae in Sera from Patients with Disseminated Gonococcal Infection

Abstract

Bactericidal and opsonic activities in convalescent-phase sera from patients with disseminated gonococcal infection (DGI) were analyzed with use of the patients' infecting strains and other strains of Neisseria gonorrhoeae. Serum from a patients with C8 deficiency was opsonic for her first DGI isolate grown on solid medium or in chick embryos; with added complement the serum was bactericidal (at a dilution of 1:320). Her serum was not bactericidal for nine other isolates from patients with DGI. Only one of the other patients with DGI had detectable serum bactericidal activity (dilution, 1:2,5) against her own isolate; this patient's serum was also active against one other DGI isolate. Opsonization was detectable only in sera that were potentially bactericidal and could be distinguished from bactericidal activity only with C8-deficient serum. The isolates from patients with DGI were of an auxotype different from that of most other gonococci, and most of the isolates tested were not killed by sera from patients with uncomplicated gonorrhea, even though these wera killed other gonococci. Thus, isolates from patients with DGI appeared to be significantly different from other gonococcal isolates.

The Effect of Specific Antiserum on the Resistance of Neisseria gonorrhoeae to Intracellular Killing by Phagocytes of Human Blood

“…The enhancement of killing was a rapid effect, being noticed within 5 min ( Table 2). As all sera were heat inactivated, the mechanism of intracellular killing must differ from that described by Brooks, Israel & Petersen (1976) which required a heat-labile factor, probably complement. Antiserum against strain BS, which contained BSDH and BSSH organisms, was equally effective in promoting killing of both the naturally resistant organisms ('BSDH) and the naturally susceptible organisms (BSSH).…”

Mechanism of action of blocking immunoglobulin G for Neisseria gonorrhoeae.

“…Clinical isolates of GC require antibody for killing. Natural bactericidal antibody for serum-sensitive isolates ofGC is present in normal human serum (1,2), and bactericidal antibody for serum-resistant isolates is often present in convalescent human disseminated gonococcal infection (DGI) serum (3)(4)(5). However, the presence of IgGclass blocking antibodies, which are often found in normal human serum, may preclude killing of serum-resistant strains of GC (6,7).…”

Immune-enhanced Phagocytosis of Neisseria gonorrhoeae by Macrophages: Characterization of the Major Antigens to which Opsonins are Directed

“…Potential roles have been suggested for bactericidal antibodies (Brooks et al, 1976;Buchanan et al, 1978;Kasper et al, 1977;McCutchan et al, 1976;, for local secretory antibodies blocking attachment (O'Reilly et a!., 1976;Tramont, 1977), and for opsonic antibodies (Ofek et al, 1974;Penn et al, 1977). That the latter might play a significant role is supported by the observation that virulent Type 1 organisms are more resistant to phagocytosis (Blake & Swanson, 1975;Dilworth et al, 1975;Punsalang & Sawyer, 1973) and that opsonic antibody is acquired in some patients with gonorrhoea (Bisno et al, 1975).…”