Analysis of Neisseria gonorrhoeae in Ontario, Canada, with decreased susceptibility to quinolones by pulsed-field gel electrophoresis, auxotyping, serotyping and plasmid content.
The incidence of Neisseria gonorrhoeae with reduced susceptibility to quinolones increased from 0.18% (63 of 3285) in 1992 to 0.56% (15 of 2663) in 1993 and 0.62% (46 of 2846) in 1994. In all, 65 of the 67 isolates of Neisseria gonorrhoeae with decreased susceptibility to quinolones were characterised by pulsed-field gel electrophoresis (PFGE), auxotyping, serotyping and plasmid content. The strains were distributed among 14 auxotype/serovar (A/S) classes. Thirty isolates (46.2%) which were penicillin-susceptible with ciprofloxacin MIC90 of 0.12 mg/L and norfloxacin MIC90 of 1.0 mg/L belonged to a single A/S class, OUHL/IA-2. All but two of the 30 isolates had identical PFGE restriction profiles with NheI restriction endonuclease. Fifteen isolates (23.1%) with MICs in the intermediate (or resistant) categories for penicillin and with ciprofloxacin and norfloxacin MIC90 of 0.25 and 4.0 mg/L and (0.5 and 4.0 mg/L) respectively, belonged to A/S class P/IB-1. The 15 isolates showed nine different patterns with NheI and eight patterns with SpeI restriction endonucleases. Two of three beta-lactamase-producing (PPNG) isolates belonged to A/S class P/IB-5 and had a dissimilar PFGE restriction profile with NheI endonuclease; the other isolate belonged to A/S class P/IB-8. The remaining 17 isolates were distributed among 11 A/S classes. Three isolates within the common A/S class NR/IB-1 were subdivided into two types by PFGE as were three isolates belonging to A/S class NR/IB-2. Overall the 65 isolates of N. gonorrhoeae were distributed into 30 NheI and 26 SpeI macrorestriction profiles. All but one isolate harboured the 2.6-MDa cryptic plasmid and 18 isolates carried the 24.5-MDa transferable plasmid. The three PPNG isolates carried the 4.5-MDa Asian beta-lactamase-producing plasmid and a 25.2-MDa conjugative plasmid was found in the two TRNG isolates.
Harnett
N
N
Central Public Health Laboratory, Ontario Ministry of Health, Toronto, Canada.
Brown
S
S
Riley
G
G
Terro
R
R
Krishnan
C
C
Pauzé
M
M
Yeung
K H
KH
D042462:4-Quinolones; D000890:Anti-Infective Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D006069:Gonorrhea / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D015994:Incidence; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000145:classification / Q000187:drug effects*; D009864:Ontario / Q000453:epidemiology; D010957:Plasmids; D015183:Restriction Mapping; D012703:Serotyping
D042462:4-Quinolones; D000890:Anti-Infective Agents; D004269:DNA, Bacterial