Detection of a novel ?cryptic? plasmid of about 7.8 MDal in a non-penicillinase-producing Neisseria gonorrhoeae isolate from Munich

1990 ◽  
Vol 6 (1) ◽  
pp. 96-98
Author(s):  
D. Abeck ◽  
H. C. Korting ◽  
W. Grimm ◽  
R. Zaba
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Cryptic Plasmid ◽  
Gonorrhoeae Isolate

scholarly journals Clinical Neisseria gonorrhoeae isolate with a N. meningitidis porA gene and no prolyliminopeptidase activity, Sweden, 2011 – danger of false-negative genetic and culture diagnostic results

2012 ◽  
Vol 17 (9) ◽  
Author(s):  
D Golparian ◽  
E Johansson ◽  
M Unemo
Keyword(s):  
Neisseria Gonorrhoeae ◽  
False Negative ◽  
Gonorrhoeae Strain ◽  
Negative Results ◽  
False Negative Results ◽  
Gonorrhoeae Isolate

We describe a Neisseria gonorrhoeae strain, found in Sweden in 2011, that harbours a N. meningitidis porA gene causing false-negative results in PCRs targeting the gonococcal porA pseudogene. Furthermore, the strain had no prolyliminopeptidase (PIP) activity that many commercial biochemical kits for species verification in culture rely on. Enhanced awareness of the spread of such strains and screening for them can be crucial.

scholarly journals Sequence-specific DNA uptake in transformation of Neisseria gonorrhoeae

1982 ◽  
Vol 152 (3) ◽  
pp. 1071-1077
Author(s):  
J F Graves ◽  
G D Biswas ◽  
P F Sparling
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Dna Sequence ◽  
Plasmid Dna ◽  
Cryptic Plasmid ◽  
Dna Uptake ◽  
Restriction Fragments

Piliated, competent gonococci are known to preferentially take up homologous transforming DNA into the cell. We examined the mechanism for DNA uptake with pFA10, a hybrid 11.5-kilobase (kb) penicillin-resistant (Pcr) plasmid composed of heterologous DNA from a 7.2-kb Pcr plasmid and homologous DNA from a 4.2-kb gonococcal cryptic plasmid. The presence of the gonococcal cryptic plasmid DNA in the hybrid resulted in markedly increased transformation efficiencies in isogenic crosses as compared with the parent 7.2-kb Pcr plasmid. Uptake of 32P-end-labeled MspI or TaqI restriction fragments of the hybrid was limited to fragments entirely derived from the 4.2-kb gonococcal cryptic plasmid, indicating that DNA uptake was probably dependent on the presence of a specific DNA sequence. Since Haemophilus DNA did not inhibit transformation by the hybrid Pcr plasmid, the gonococcal DNA uptake sequence is different from the known sequence involved in homologous DNA uptake by Haemophilus spp.

scholarly journals Plasmid content, auxotype and protein-I serovar of gonococci isolated in the Gambia

1987 ◽  
Vol 99 (3) ◽  
pp. 669-674 ◽  
Author(s):  
A. P. Johnson ◽  
D. Abeck ◽  
R. A. Wall ◽  
D. C. W. Mabey ◽  
D. Taylor-Robinson
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Plasmid Profile ◽  
The Gambia ◽  
Cryptic Plasmid ◽  
Conjugative Plasmid ◽  
Plasmid Content ◽  
Conjugative Plasmids ◽  
Significant Difference ◽  
Heterogeneous Nature

SUMMARYTwenty-nine strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) and 30 non-penicillinase-producing strains, all isolated in the Gambia, were characterized in terms of their plasmid content, auxotype and protein-I serovar. Sixty-two per cent of the PPNG strains contained the 3·2 MDa penicillinasecoding plasmid, and 38% had the 4·4 MDa plasmid. All the PPNG strains contained the 2·6 MDa cryptic plasmid but lacked the 24·4 MDa conjugative plasmid. In contrast, 46·7% of the non-PPNG strains harboured only the cryptic plasmid while 16·7% contained both the cryptic and conjugative plasmids. Seventeen per cent of the non-PPNG strains contained the conjugative plasmid only and 20% lacked plasmids.The PPNG and non-PPNG strains also differed in terms of their protein-I serovar. Eighty-six per cent of the PPNG strains belonged to serogroup 1A, whereas the majority (60%) of non-PPNG strains belonged to serogroup IB. There was no significant difference in the auxotypes of the PPNG and non-PPNG strains, with both groups consisting predominantly of prototrophic and prolinerequiring strains, with a minority of strains requiring arginine. When the 59 strains were each characterized in terms of their combined plasmid profile, auxotype and serovar, 39 different combinations were noted, which indicates the heterogeneous nature of the gonococcal population found in the Gambia.

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