Penetration of Penicillin into Human Phagocytes Containing Neisseria gonorrhoeae: Intracellular Survival and Growth at Optimum Concentrations of Antibiotic

Veale, D. R.; Finch, Hazel; Smith, H.; Witt, Kristina

doi:10.1099/00221287-95-2-353

Cited by 38 publications

(21 citation statements)

References 14 publications

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“…However, it is not easy to demonstrate this protection phenomenon consistently; much depends, amongst other things, on the experimental techniques and upon the type of ingested micro-organism (see Veale et al, 1975Veale et al, , 1976Veale et al, and 1979. Whereas protection of an intracellular staphylococcal population obtained by simple washing procedures of extracellular bacteria was complete at a penicillin concentration of 1 pg/ml, the protection was only partial at 5 pg/ml.…”

Section: Discussionmentioning

confidence: 99%

Intraphagocytic Protection of Staphylococci from Extracellular Penicillin

Lam

Mathison

1982

Journal of Medical Microbiology

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SUMMARY. In a system in which unphagocytosed bacteria were removed by differential centrifugation after a 30-min phagocytosis period, staphylococci associated with rabbit polymorphonuclear (PMN) leukocytes were completely protected from the effects of benzyl penicillin 1 pg/ml, but not completely protected from the effects of 5 pg/ml. When unphagocytosed bacteria were lysed with lysostaphin, effective protection could be observed over a range of penicillin concentrations from 0.25 to 200 pg/ml. 14C-benzyl penicillin failed to accumulate in rabbit PMN leukocytes, whether or not they had previously phagocytosed staphylococci, in conditions in which mouse peritoneal macrophages readily accumulated penicillin. Mixed granule extracts prepared from the PMN leukocytes interacted synergically with penicillin against staphylococci at physiological pH (7.2) but failed to show synergy at an intraphagolysosomal p H of 5.0 unless the bacteria were first sublethally treated with penicillin. Experiments in which the pH value of culture media was changed either from 7.2 to 5.0 or from 5.0 to 7.2 indicated that the partial nature of the protective effect of the intraphagolysosomal environment could be attributed to the growthlimiting effects of the low phagolysosomal pH, which prevents full expression of the synergic potential of granule contents and penicillin. The concentration-dependent nature of the protection and its incompleteness are explained by supposing that a proportion of the staphylococci not ingested during the 30-min phagocytosis period are modified by penicillin in a way that opsonises them and potentiates the intrinsic bactericidal mechanisms of the PMN leukocytes when the bacteria are subsequently ingested.

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Section: Discussionmentioning

confidence: 99%

Intraphagocytic Protection of Staphylococci from Extracellular Penicillin

Lam

Mathison

1982

Journal of Medical Microbiology

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“…Strain BSV was more resistant than strain BS to fresh human serum alone (Penn et al, 1975) and in the supernatants strain BSV seemed to be more resistant than strain BS to the bactericidal mixture containing penicillin ( Table 2 ) . In most cases, however, the supernatant counts at 2 10 4 h were so much lower than the deposit counts that the latter could only represent intracellular organisms (see Veale et al, 1976). * Electron microscopy indicated that most of these organisms were intracellular.…”

Section: Phagocytosis Of N Gonorrhoeae Grown In Vivo 347mentioning

confidence: 99%

“…One h after mixing (all experiments), and also at 15 and 30 min after mixing in some experiments, tubes were taken and the viable organisms in the supernatants and in the deposits attached to the glass were counted as described by Veale et al (1976). From the total number of phagocytes attached to the glass, the proportion of them containing gonococci, and the average number of gonococci ingested by them , the total gonococci visibly associated with phagocytes per slide was estimated.…”

Section: Phagocytosis Of N Gonorrhoeae Grown In Vivo 343mentioning

confidence: 99%

“…These were described by Veale et al (1975) Phagocytosis tests. Modified forms of the tests for assessing the relative abilities of gonococcal strains to resist ingestion and digestion by phagocytes described by Witt et al (1976) andVeale et al (1976) were used. The ratio of gonococci to PMN phagocytes was reduced from between 20: I and 100: I to approximately I : I and particular attention was paid to total and viablecounts of gonococci found in phagocyte deposits that attach to glass during the first I h ingestion period.…”

Section: Phagocytosis Of N Gonorrhoeae Grown In Vivo 343mentioning

confidence: 99%

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Resistance of Neisseria gonorrhoeae Grown in vivo to Ingestion and Digestion by Phagocytes of Human Blood

Witt¹,

Veale

Finch

et al. 1976

Journal of General Microbiology

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S U M M A R YAttempts to study quantitatively the phagocytosis of gonococci from urethral pus failed because of the small numbers of organisms and technical difficulties. However, gonococci from chambers implanted subcutaneously in guinea pigs, which were similar to gonococci from urethral pus in their resistance to killing by human serum, were obtained in sufficient quantities for comparison in phagocytosis tests with the in vitro grown strain from which they were derived.Microscopic and viable counts of gonococci in phagocytes showed that in vivo grown organisms (strain BSV) were readily phagocytosed by human polymorphonuclear phagocytes. There was little difference between BSV organisms and the in vitro grown organisms (strain BS) in resistance to ingestion. There was, however, a marked difference in the intracellular survival of strains BSV and BS during the first hour of phagocytosis. Whereas BSV organisms survived well, many BS organisms were killed. Subsequently, strain BSV and the survivors of the strain BS inoculum responded similarly to the intracellular bactericidins. These results were supported by electron microscopy of infected phagocytes.Resistance of gonococci in vivo to ingestion and digestion by human phagocytes seem to be important facets of the pathogenesis of gonorrhoea. INTRODUCTIONStrongly staining gonococci are seen both extracellularly and intracellularly in urethral pus from patients with gonorrhoea. The presence of extracellular organisms suggests overloading of phagocytic capacity and indicates that some gonococci in vivo may resist phagocytosis. However, the presence of intracellular organisms shows that phagocytosis occurs and, further, that gonococci may resist the intracellular bactericidins. Thus resistance to ingestion and digestion by polymorphonuclear phagocytes (PMN phagocytes), the predominant cell type in urethral pus, would be important in acute infection; and survival inside the fewer mononuclear phagocytes (MN phagocytes) could be important in chronic infection.Pilated (Dilworth et al., 1975). Thus, resistance to ingestion appears to be correlated with the virulence for man of the Kellogg types, but whether or not pili are responsible for the resistance is still a matter of dispute (Swanson et al., 1974).With regard to resistance to intracellular killing, appreciable numbers of a pilated, small-colony-forming strain of gonococcus (BS) resembling Kellogg type 2 survived and multiplied within human buffy-coat phagocytes (predominantly PMN phagocytes) over I 5 h and also survived for at least 6 h in the few MN phagocytes that could be separated from the buffy coat (Veale et al., I 976). A non-pilated, large-colony-forming strain (AL) resembling Kellogg type 4 survived at a much lower level than the BS strain and was destroyed in 10 to 12 h (Veale et al., 1976). Thus, with strains BS and AL, resistance to digestion could be correlated with infectivity for guinea-pig chambers (Veale et al., 1975) and, by analogy with the Kellogg types, with potential virulence for man. These...

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“…These were haemoglobin agar, described by Veale et al (1976), and a clear agar medium (AG agar) modified from that of Amies & Garabedian (1967) by Veale et al Subcutaneously implanted guinea-pig chambers. Male Dunkin-Hartley guinea pigs (grade 2; Olac, Banbury, Oxfordshire; 600 g) received two or four chambers (4 to 5 ml) which were implanted, inoculated and sampled as described by Veale et al (1975).…”

Section: Gonococcal Strain Grown In Vitromentioning

confidence: 99%

Morphological, Biological and Antigenic Properties of Neisseria gonorrhoeae Adapted to Growth in Guinea-Pig Subcutaneous Chambers

Penn

Veale

et al. 1976

Journal of General Microbiology

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S U M M A R YGonococci (strain ss3) passaged three times and harvested directly from plastic chambers implanted subcutaneously in guinea pigs were compared with the parent strain (BS) grown in vitro. The strain grown in vivo produced smaller colonies than that grown in vitro and when examined directly in chamber fluid was sometimes not pilated. It was more resistant to the bactericidal action of human serum and more infective for guinea-pig chambers. In gel diffusion, extracts of the organisms adapted in vivo and cultured once on agar appeared to contain one or two antigens that were different from those in extracts of the in vitvo grown organisms; and on polyacrylamide gels, electrophoresis of similar extracts showed one or more protein components for strain ss3 which were not seen for strain BS. Gonococci grown in guinea-pig subcutaneous chambers appear to be suitable for studies on the determinants of gonococcal pathogenicity.

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Penetration of Penicillin into Human Phagocytes Containing Neisseria gonorrhoeae: Intracellular Survival and Growth at Optimum Concentrations of Antibiotic

Cited by 38 publications

References 14 publications

Intraphagocytic Protection of Staphylococci from Extracellular Penicillin

Intraphagocytic Protection of Staphylococci from Extracellular Penicillin

Resistance of Neisseria gonorrhoeae Grown in vivo to Ingestion and Digestion by Phagocytes of Human Blood

Morphological, Biological and Antigenic Properties of Neisseria gonorrhoeae Adapted to Growth in Guinea-Pig Subcutaneous Chambers

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