Inhibition of staphylococcal delta-haemolysin by human serum lipoproteins

Whitelaw, D.D.

doi:10.1016/0378-1097(78)90021-6

Cited by 6 publications

(12 citation statements)

References 7 publications

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“…The E280, specific gravity and haemolysin-inhibition titres of fractions were measured. On a preparative scale, lipoproteins were removed from 25 ml of antiserum by centrifugation in an MSE BXIV Zonal rotor (Whitelaw and Birkbeck, 1978). Lipoprotein-free fractions were bulked, concentrated to 20 ml, and 10 ml of saturated (NH&S04 solution were added.…”

Section: Methodsmentioning

confidence: 99%

“…Lipoproteins were removed by ultracentrifugation in a gradient of potassium bromide (Whitelaw and Birkbeck, 1978); 2 g of KBr dissolved in 3 ml of serum was overlayered with KBr solutions in 3 5 0~~ EDTA (3 mi of each) of specific gravity 1.36, 1.28, 1.20,l. 12 and 1-04 g/ml in 25-ml centrifuge tubes.…”

Section: Methodsmentioning

confidence: 99%

“…Assays of lipoproteins and immunoglobulins for haemolysin-inhibiting activity were done as previously described (Whitelaw and Birkbeck, 1978); one haemolysininhibitory unit (HIU) was the amount of inhibitor that completely prevented lysis of cod erythrocytes after 30 min. at 20°C.…”

Section: Methodsmentioning

confidence: 99%

“…2b, fractions 7-10 and 1 and 2 respectively) but in immune sera the majority of the inhibitory activity was present in high-density fractions ( fig. 2a, activities of anti-6-haemolysin sera were associated with the lipoprotein fractions (Whitelaw and Birkbeck, 1978), with the fraction of lipoprotein-free antiserum precipitated by 33% (v/v) saturated (NH4)S04 and with an IgG fraction obtained by DEAE cellulose chromatography (table I and fig. 3).…”

Section: Properties Of Antiseramentioning

confidence: 99%

“…An involvement in staphylococcal enteritis has been suggested because 6 haemolysin activates adenylate cyclase in the ileum and increases vascular permeability in guinea-pig skin O'Brien and Kapral, 1976). Serum lipoproteins and phospholipids bind to 6 haemolysin (Kapral, 1972;Whitelaw and Birkbeck, 1978) and this has hindered many attempts to demonstrate the immunogenicity of the molecule. Whereas Elek (1 958), McLeod (1 963), Kayser and Raynaud (1 965) and Caird and Wiseman ( 1970) claimed to have induced specific antibodies to 6 haemolysin, no evidence was presented that nonspecific serum inhibitors had been removed.…”

Section: Plate Xi11mentioning

confidence: 99%

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Immunogenicity and molecular characterisation of staphylococcal haemolysin (Plate XIII)

Birkbeck¹,

Whitelaw²

1980

Journal of Medical Microbiology

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Properties Of Antiseramentioning

confidence: 99%

Section: Plate Xi11mentioning

confidence: 99%

See 3 more Smart Citations

Immunogenicity and molecular characterisation of staphylococcal haemolysin (Plate XIII)

Birkbeck¹,

Whitelaw²

1980

Journal of Medical Microbiology

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In vitro synthesis of the delta-lysin of Staphylococcus aureus

Lee¹,

Birkbeck²

1984

Infect Immun

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The stability of mRNA for the 8-lysin of Staphylococcus aureus was determined by measuring the residual lysin synthesis after inhibition of DNA-dependent RNA polymerase activity with rifampin. At the late logarithmic-early stationary phase of growth the 5-lysin mRNA was very stable, with a half-life of ca. 20 min. Total cellular RNA was extracted from S. aureus and translated with a modified Escherichia coli S-30 system; 8-lysin was identified amongst the translation products by immunoprecipitation and immunoabsorption. The 8-lysin synthesized in vitro was of a size similar to mature 5-lysin and did not require a signal sequence for secretion from the cell.

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Delta-like toxin produced by coagulase-negative staphylococci is associated with neonatal necrotizing enterocolitis

Scheifele¹,

Bjornson²,

Dyer³

et al. 1987

Infect Immun

103

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Necrotizing enterocolitis (NEC) is a serious neonatal disorder of uncertain cause, although fecal bacteria have been implicated in some outbreaks. We examined coagulase-negative staphylococci (CONS) as possible etiologic agents. In our unit, CONS colonized the bowels of most infants studied, including 46% of 70 NEC cases (mean concentration, 109 1 CFU/g of stool). Over 90% of tested isolates produced a hemolysin resembling delta toxin of Staphylococcus aureus. Toxin purified from a NEC-associated isolate of Staphylococcus epidermidis resembled reference delta toxin from S. aureus in size, biologic properties, and antigenicity. This delta-like toxin was enteropathic, causing mucosal necrosis and hemorrhage in injected loops of the bowels of infant rats. Adjacent, nonexposed bowel remained normal, as did loops injected with lecithin-neutralized toxin. Using a new enzyme-linked immunosorbent assay (ELISA), we detected delta-like toxin in the stools of 11 of 35 infants colonized with CONS positive for delta-like toxin (Tox+). Positive tests were strongly associated with NEC. Of 18 cases with Tox+ CONS, 10 were positive (56%), whereas only 1 of 17 control infants so colonized was positive (6%, P = 0.002). In NEC patients, the mean fecal toxin concentration was 1,012 ng/g. Toxicity to fibroblasts was demonstrable in filtrates of each of six ELISA-positive samples tested but was absent in all five ELISA-negative samples tested. We conclude that delta-like toxin is elaborated in the bowels of some infants with Tox+ CONS, and its association with NEC suggests that such CONS are enteropathic. In our unit, this mechanism was apparent in 23% of 44 recent cases of endemic NEC.

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Inhibition of staphylococcal delta-haemolysin by human serum lipoproteins

Cited by 6 publications

References 7 publications

Immunogenicity and molecular characterisation of staphylococcal haemolysin (Plate XIII)

Immunogenicity and molecular characterisation of staphylococcal haemolysin (Plate XIII)

In vitro synthesis of the delta-lysin of Staphylococcus aureus

Delta-like toxin produced by coagulase-negative staphylococci is associated with neonatal necrotizing enterocolitis

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