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Characterisation of penicillinase producing gonococci isolated in Munich, 1981-6
D Abeck1, A P Johnson, H C Korting
1Division of Sexually Transmitted Diseases, MRC Clinical Research Centre, Harrow, Middlesex, England.
Abstract:
Twenty three penicillinase producing strains of Neisseria gonorrhoeae (PPNG) isolated in Munich from 1981 to 1986 were characterised in terms of their plasmid content, auxotypes, protein I serovars, and sensitivity to antibiotics. Sixteen strains (70%) harboured a 4.4 megadalton plasmid, with 13 of these strains also containing a 24.4 megadalton plasmid. Seven strains (30%) contained a 3.2 megadalton plasmid, with only one of them containing a 24.4 megadalton plasmid. Thirteen strains (57%) were prototrophic, eight (35%) required proline, one required arginine, and one required proline and arginine for growth. Serovar analysis showed that 16 strains (70%) belonged to the protein IB serogroup and comprised four serovars (IB-1, IB-5, IB-7, and IB-8). The seven strains belonging to the IA serogroup also comprised four serovars (IA-2, IA-4, IA-6, and IA-10). Although 18 different categories of plasmid, auxotype, and serovar were found in the 23 PPNG strains, there was a similarity between the auxotypes in terms of the range of serovars they comprised. Measurement of minimum inhibitory concentrations (MICs) of antibiotics for the strains showed that they were all susceptible in vitro to spectinomycin (MIC less than or equal to 32 mg/l), enoxacin (MIC less than or equal to 0.25 mg/l), cefotaxime, ciprofloxacin, and ceftriaxone (MICs less than or equal to 0.064 mg/l), whereas about half showed some resistance to tetracycline or cefotiam, or both.
Insights
Penicillinase-producing Neisseria gonorrhoeae (PPNG) strains from Munich showed diverse plasmid, auxotype, and serovar profiles. All PPNG strains remained susceptible to newer antibiotics like ciprofloxacin and ceftriaxone.
Area of Science:
- Microbiology
- Genetics
- Epidemiology
Background:
- Penicillinase-producing Neisseria gonorrhoeae (PPNG) poses a significant public health challenge.
- Characterizing PPNG strains is crucial for understanding transmission and guiding treatment strategies.
Purpose of the Study:
- To comprehensively characterize PPNG strains isolated in Munich between 1981 and 1986.
- To analyze plasmid content, auxotypes, protein I serovars, and antibiotic susceptibility patterns.
Main Methods:
- Plasmid content was analyzed using molecular methods.
- Auxotyping was performed to determine growth requirements.
- Protein I serovar typing was conducted.
- Minimum inhibitory concentrations (MICs) were measured for various antibiotics.
Main Results:
- Most strains (70%) harbored a 4.4 megadalton plasmid, often with a 24.4 megadalton plasmid.
- A significant proportion of strains were prototrophic (57%) or required proline (35%) for growth.
- Strains belonged to protein IB (70%) and IA serogroups, with multiple serovars identified within each.
- All strains were susceptible in vitro to spectinomycin, enoxacin, cefotaxime, ciprofloxacin, and ceftriaxone.
Conclusions:
- Despite 18 distinct categories of plasmid, auxotype, and serovar, similarities were observed in auxotype-serovar relationships.
- PPNG strains from this period exhibited susceptibility to key antibiotics, including newer agents like ciprofloxacin and ceftriaxone.
- These findings provide valuable epidemiological data on PPNG in Munich during the specified timeframe.