ISSN:
1572-9699
Keywords:
Neisseria genorrhoeae
;
complement killing
;
CMP-NANA
;
serum resistance
;
sialyltransferase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Freshly isolated gonococci upon subculture are readily lysed by normal human serum although a few strains remain inherently resistant to the complement activity. The sensitive gonococci can be converted to serum resistance by incubation with a host derived factor referred to as cytidine 5′-monophospho-N-acetylneuraminic acid (CMP-NANA). These gonococci resist complement mediated killing due to their sialylation of an epitope structure on a component of lipo-oligosaccharide (LOS). In the present study, the kinetics of conversion to serum resistance by the action of sialyltransferase (STase) inNeisseria gonorrhoeae was followed with very low concentrations of CMP-NANA. This conversion could not be perceived at 2×10−3 nmol.ml−1 but was fully attainable from 8×10−3 to 2×10−2 nmol.ml−1 CMP-NANA. When pretreated up to 100 min in presence of the very low concentration of 2×10−3 nmol.ml−1, a potentiating effect on the conversion of gonococci by 2×10−2 nmol.ml−1 was observed in relation to the time of preincubation. This action was abolished after exposure to a subinhibitory concentration of chloramphenicol (0.5 µg.ml−1). The gonococci recovered their ability to convert to serum resistance following adequate washing. The potential for increase in STase activity should be of interest for understanding the conversion from a serum sensitive to a serum resistance state.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00873691
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