Isolation and Analysis of Radiolabeled Meningococcal Endotoxin

Giardina, Peter C.; Weiss, Jerrold; Gibson, Brad; Apicella, Michael A.

doi:10.1385/1-59259-149-3:441

Cited by 3 publications

(5 citation statements)

References 36 publications

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“…The samples were dried overnight in a 37°C incubator. Further purification was performed using a standard acid-base hydrolysis procedure, with some minor modifications (13). To prepare derivatives for gas chromatographymass spectrometry (GC-MS) analysis, the free fatty acids were first methylated with diazomethane in methanol (equal volumes), allowed to sit at room temperature for 10 min, and then dried under a stream of N 2 .…”

Section: Methodsmentioning

confidence: 99%

Intracellular Survival of Neisseria gonorrhoeae in Male Urethral Epithelial Cells: Importance of a Hexaacyl Lipid A

et al. 2002

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Neisseria gonorrhoeae is a strict human pathogen that invades and colonizes the urogenital tracts of males and females. Lipooligosaccharide (LOS) has been shown to play a role in gonococcal pathogenesis. The acyl transferase MsbB is involved in the biosynthesis of the lipid A portion of the LOS. In order to determine the role of an intact lipid A structure on the pathogenesis of N. gonorrhoeae, the msbB gene was cloned and sequenced, a deletion and insertion mutation was introduced into N. gonorrhoeae, and the mutant strain was designated 1291A11K3. Mass spectrometric analyses of 1291A11K3 LOS determined that this mutation resulted in a pentaacyl rather than a hexaacyl lipid A structure. These analyses also demonstrated an increase in the phosphorylation of lipid A and an increase in length of the oligosaccharide of a minor species of the msbB LOS. The interactions of this mutant with male urethral epithelial cells (uec) were examined. Transmission and scanning electron microscopy studies indicated that the msbB mutants formed close associations with and were internalized by the uec at levels similar to those of the parent strain. Gentamicin survival assays performed with 1291A11K3 and 1291 bacteria demonstrated that there was no difference in the abilities of the two strains to adhere to uec; however, significantly fewer 1291A11K3 bacteria than parent strain bacteria were recovered from gentamicin-treated uec. These studies suggest that the lipid A modification in the N. gonorrhoeae msbB mutant may render it more susceptible to innate intracellular killing mechanisms when internalized by uec.Neisseria gonorrhoeae is a strict human pathogen, which invades and colonizes the epithelia of the urogenital tracts of both males and females (2, 12, 18). The lipooligosaccharide (LOS) of N. gonorrhoeae has been shown to play a role in the pathogenesis of human infections (19,40). The LOS is composed of three major components: the oligosaccharide chain extensions, the core region, and lipid A. The oligosaccharide extensions of the LOS contain determinants which resemble human glycosphingolipid antigens that play a role in molecular mimicry. Studies have also shown that the oligosaccharide region of the LOS can be involved in receptor-mediated interactions (17,19,37). Lipid A of N. gonorrhoeae is similar in structure to lipid A from other gram-negative bacteria (31,44,46). htrB (alternatively lpxL or waaM) is involved in the biosynthesis of lipid A of lipopolysaccharides (LPSs) and LOSs. HtrB is one of the 2-keto-3-deoxyoctulosonic acid (Kdo)-dependent acyl transferases responsible for the addition of a secondary acyl substitution on the lipid A portion of LPS or LOS. The htrB gene has been well characterized for Escherichia coli, Haemophilus influenzae, and Salmonella enterica serovar Typhimurium (6,36,44). Mutations in this gene have been shown to have a number of effects on the organism. One such effect is temperature sensitivity. E. coli, H. influenzae, and S. enterica serovar Typhimurium htrB mutants have all been show...

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Section: Methodsmentioning

confidence: 99%

Intracellular Survival of Neisseria gonorrhoeae in Male Urethral Epithelial Cells: Importance of a Hexaacyl Lipid A

et al. 2002

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“…However, differential expression of the attached oligosaccharides leads to phase variation and multiple glycoforms and immunotypes in the LOS (170,171). The LOS of N. meningitidis provides a good example, where the varying composition of the ␣-chain and differential substitution of the side-branch heptose (␤-and ␥-chains), and sialylation all generate heterogeneity ( Figure 10).…”

Section: Lipopolysaccharide Endotoxinsmentioning

confidence: 99%

“…The biosynthesis of lipooligosaccharide (LOS) in mucosal pathogens represents a special case in terms of structural heterogeneity because many are subject to high-frequency phase variation [reviewed in (169,170)]. The addition of the oligosaccharide extensions in LOS follows essentially the same mechanism used for the outer core.…”

Section: Phase Variation and The Biosynthesis Of Lipooligosaccharidementioning

confidence: 99%

Lipopolysaccharide Endotoxins

Raetz

Whitfield

2002

Annu. Rev. Biochem.

3,953

4,309

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“…meningitidis, also called meningococcus, is a Gramnegative, aerobic, diplococcus bacterium and a member of the family Neisseriaceae of the β subclass of the Proteobacteria class (4,10). The organism is approximately 0.6-1 μm in diameter and has flattened adjacent sides.…”

Section: Microbiologymentioning

confidence: 99%

“…These serogroups differ in their geographic distribution and lethality (6). The manifestations include pharyngitis, fever, renal failure, disseminated intravascular coagulation (DIC), and meningococcemia with or without meningitis (7)(8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

Meningococcemia in Adults: A Review of the Literature

Takada

Fujiwara

Inoue³

et al. 2016

Intern. Med.

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We mainly refer to the acute setting of meningococcemia. Meningococcemia is an infection caused by Neisseria meningitidis, which has 13 clinically significant serogroups that are distinguishable by the structure of their capsular polysaccharides. N. meningitidis, also called meningococcus, is a Gram-negative, aerobic, diplococcus bacterium. The various consequences of severe meningococcal sepsis include hypotension, disseminated intravascular coagulation (DIC), multiple organ failure, and osteonecrosis due to DIC. The gold standard for the identification of meningococcal infection is the bacteriologic isolation of N. meningitidis from body fluids such as blood, cerebrospinal fluid (CSF), synovial fluid, and pleural fluid. Blood, CSF, and skin biopsy cultures are used for diagnosis. Meningococcal infection is a medical emergency that requires antibiotic therapy and intensive supportive care. Management of the systemic circulation, respiration, and intracranial pressure is vital for improving the prognosis, which has dramatically improved since the wide availability of antibiotics. This review of the literature provides an overview of current concepts on meningococcemia due to N. meningitidis infection.

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Isolation and Analysis of Radiolabeled Meningococcal Endotoxin

Cited by 3 publications

References 36 publications

Intracellular Survival of Neisseria gonorrhoeae in Male Urethral Epithelial Cells: Importance of a Hexaacyl Lipid A

Intracellular Survival of Neisseria gonorrhoeae in Male Urethral Epithelial Cells: Importance of a Hexaacyl Lipid A

Lipopolysaccharide Endotoxins

Meningococcemia in Adults: A Review of the Literature

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