Prevalence of multiple antibiotic resistance in Neisseria gonorrhoeae.

Platt, D J

doi:10.1136/sti.52.6.384

Cited by 4 publications

(5 citation statements)

References 17 publications

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“…These reports have aroused widespread concern. However, reports on the prevalence of antibiotic resistance in the gonococcus in fact suggest a significant decrease in resistance since 1968 (31), with few reports of MICs greater than 1 ug/ml and none in excess of 8 ug/ml. It should be noted that the vast majority of strains currently resistant to benzylpenicillin do not produce /8-lactamase.…”

Section: Resultsmentioning

confidence: 99%

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Transfer of Plasmid-Borne Beta-Lactamase in Neisseria gonorrhoeae

Baron¹,

Saz

Kopecko³

et al. 1977

Antimicrob Agents Chemother

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Neisseria gonorrhoeae strain GC82 contains a plasmid specifying a 8-lactamase (,3-Lam+}. Mixed incubation of strain GC82 with a penicillin-susceptible (X-Lam-), streptomycin-resistant mutant of strain GC9 results in the expression of f8-lactamase activity and streptomycin resistance in the transcipients. The frequency of transfer of the plasmid-specified resistance to penicillin seems to be proportional to the initial input ratio of the mating mixture of donor to recipient and to correlate positively with bacterial density. Cell-to-cell transmission of the deoxyribonucleic acid (DNA) appears to be by a conjugal mechanism or, alternatively, by an as yet undescribed transducing phage. Additionally, whole-cell DNA from a f8-lactamase-producing strain could be used to transform streptomycin-resistant recipients, resulting in the expression of both 8-lactamase activity and streptomycin resistance in the transformants, and purified gonococcal plasmid DNA transformed Escherichia coli but not the gonococcus. Circular DNA extracted from donor GC82 comprised three molecular species (approximately 2.7, 4.8, and 25 megadaltons [Mdal]), whereas the recipients GC9-S (Ste) contained only the 2.7-Mdal cryptic DNA species. DNA from the GC9-S82 (StrW, ,8-Lam+) transcipient contained a 4.8-Mdal species in addition to the cryptic molecular species (2.7 Mdal). The finding that the transcipient will not retransfer f8-lactamase is consistent with the hypothesis that the 25-Mdal plasmid promotes mobilization of the smaller 4.8-Mdal R plasmid.Although Neisseria gonorrhoeae has been traditionally thought of as a susceptible organism, the occurrence of gonococcal strains that are relatively resistant to penicillin and other antibiotics has gradually become an important clinical problem during the past 15 years, necessitating the use of elevated dosages of penicillin. It should be noted that there have been recent indications that the minimal inhibitory concentration (MIC) for penicillin of clinical isolates has decreased somewhat (24, 31).Resistance to penicillin in bacteria is frequently associated with the presence of 18-lactamase. The literature on 83-lactamase in gramnegative bacteria has been reviewed extensively (33). A number of these resistances have been specified by R plasmids. Previously, no /8-lactamase has been reported in N. gonorrhoeae, and resistance of the gonococcus was occasioned by a change in the binding site for penicillin (34). In the last several years the isolation of /3-lactamase-producing strains ofN. gonorrhoeae has been reported (1,2,5,28,30). Recent reports have indicated the presence of plasmid-specified, /8-lactamase-containing gonococci presumably associated with very high levels of resistance in these strains (13) and conjugal transfer of the gonococcal /8-lactamase plasmid (12).Evidence for plasmid deoxyribonucleic acid (DNA) in N. gonorrhoeae strain 2686 type 1 has been presented by Engelkirk and Schoenhard (14) and Maness and Sparling (24). The presence of plasmid DNA in each of the colonial types of...

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Section: Resultsmentioning

confidence: 99%

“…It should be noted that there have been recent indications that the minimal inhibitory concentration (MIC) for penicillin of clinical isolates has decreased somewhat (24,31).…”

mentioning

confidence: 99%

Transfer of Plasmid-Borne Beta-Lactamase in Neisseria gonorrhoeae

Baron¹,

Saz

Kopecko³

et al. 1977

Antimicrob Agents Chemother

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“…'3 Thus, the SV strains 6, 75, 12, and 77 were highly susceptible to rifampin and erythromycin (fig 2, table III) and more susceptible to the penicillins than most Zero or Pro strains. Correlated high resistances characterised many Str-r strains6 12 14; strains SV407 (Zero) and SV300 (Pro) had the highest resistances to erythromycin (1 0 Mg/ml) and their resistances to other drugs were: rifampin, 0-2 and 0-05 pg/ml; benzylpenicillin, 0 5 and 0 7 U/ml; oxacillin, 5 and 10 gg/ml; tetracycline, 0 5 and 1 0 Mg/ml; chloramphenicol, 2 0 and 4 0 .g/ml; and nalidixic acid, 1 0 and 0 8 4g/ml respectively.…”

Section: Benzylpenicillin and Oxacillinmentioning

confidence: 99%

Auxotypes and antibacterial resistance to gonococci with differing susceptibilities to vancomycin.

Exner¹,

Shinners²,

Pace³

et al. 1982

Sexually Transmitted Infections

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SUMMARY The responses to vancomycin and 11 other antibacterial drugs and the nutritional requirements of gonococci recovered from two selective media were determined. Single urogenital specimens from 508 patients attending a social hygiene clinic in 1975 yielded 97 strains of Neisseria gonorrhoeae; 95 were recovered on VCNT (a modification of Thayer-Martin medium), always inoculated first, and 69 on LC medium containing lincomycin (4 l.g/ml) and colistin (5 Mg/ml).The two drugs at these concentrations in LC medium were not inhibitory for isolates from either medium. Unexpectedly, three isolates on VCNT were susceptible to vancomycin at the concentration (3 ,ug/ml) in VCNT medium; these three were typically sensitive to penicillins but were hypersusceptible to erythromycin (inhibited by (0 05 ,Ag/ml) and rifampin ((0-02 yg/ml). Resistance to streptomycin (>500 jig/ml) (22% of the strains) was correlated with increased resistance to penicillins, erythromycin, and rifampin in most instances. All streptomycin-resistant gonococci required proline, or arginine, or none of the test compounds. Strains requiring arginine, hypoxanthine, and uracil were uniformly sensitive to antibiotics but not hypersusceptible. In contrast, six strains of N gonorrhoeae isolated in Denmark required arginine (not satisfied by ornithine), hypoxanthine, and uracil and were hypersusceptible to vancomycin (inhibited by 0S5 M4g/ml), erythromycin, and rifampin. DNA-mediated transformation showed that all three hypersusceptibilities of one Danish strain were introduced together into a wild-type gonococcus, suggesting that a mutation of an env (envelope) locus might be responsible for the atypical permeability.

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“…The isolation and identification of gonococci have been previously described (Platt, 1976a). Ready-poured bi-plates, containing GC selective medium (VCNT) and GC non-selective medium, were obtained from Gibco-Biocult (Paisley, Scotland) and each batch was quantitatively quality-controlled to ensure consistent inhibitory activity.…”

Section: Correspondencementioning

confidence: 99%

“…The sensitivity of these strains to vancomycin has been attributed to env mutations which result in phenotypic hypersensitivity to antibiotics including vancomycin (Sparling et al, 1976). Observations in this department suggest that other mechanisms may also be involved in the inhibition of certain gonococcal isolates by vancomycin.The isolation and identification of gonococci have been previously described (Platt, 1976a). Ready-poured bi-plates, containing GC selective medium (VCNT) and GC non-selective medium, were obtained from Gibco-Biocult (Paisley, Scotland) and each batch was quantitatively quality-controlled to ensure consistent inhibitory activity.…”

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Inhibition of gonococci by a selective medium: disparity between isolates from sexual partners.

Platt¹,

Gerken²

1979

Sexually Transmitted Infections

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CorrespondenceTO THE EDITOR, British Journal of Venereal Diseases Inhibition of gonococci by a selective medium: disparity between isolates from sexual partners Sir, A proportion of clinical isolates of Neisseria gonorrhoeae fail to grow on selective medium containing vancomycin, colistin, nystatin, and trimethoprim (VCNT). Reyn and Bentzon (1972) and Brorson et al. (1973) reported the isolation frequency of these strains to be about 4 % and 100% respectively and found vancomycin to be the inhibitory component. The sensitivity of these strains to vancomycin has been attributed to env mutations which result in phenotypic hypersensitivity to antibiotics including vancomycin (Sparling et al., 1976). Observations in this department suggest that other mechanisms may also be involved in the inhibition of certain gonococcal isolates by vancomycin.The isolation and identification of gonococci have been previously described (Platt, 1976a). Ready-poured bi-plates, containing GC selective medium (VCNT) and GC non-selective medium, were obtained from Gibco-Biocult (Paisley, Scotland) and each batch was quantitatively quality-controlled to ensure consistent inhibitory activity. The isolation frequency of VCNT-sensitive gonococci remained constant at between 4 % and 6 %.Gonococci were isolated from 32 patients attending the department of genitourinary medicine at the West London Hospital. From four (25 %) patients and their respective sexual partners gonococci were isolated which grew on non-selective medium but failed to grow on selective medium on both primary isolation and subsequent subculture. Gonococci isolated from a further 12 patients failed to grow on selective medium on primary isolation; of these six were male and six were female.On subculture each of five isolates tested produced colonies on selective medium which were similar in size and number to a control plate lacking VCNT. The gonococci isolated from each of the 12 sexual partners grew well on selective medium on primary isolation.Reyn and Bentzon (1972) found that about 40 % of strains, inhibited by vancomycin on primary isolation, were capable of growth on subculture if a heavy inoculum was used, and they attributed this result to random variation in the original inocula and a 'training effect' during laboratory subculture. The high proportion (75 %) of disparate vancomycin sensitivity between sexual partners on primary isolation and the resistance of the vancomycin-sensitive isolates on subsequent subculture suggests that an alternative mechanism is involved.Although env mutations have been demonstrated in clinical isolates of N. gonorrhoeae (Eisenstein and Sparling, 1978), for vancomycin sensitivity to be solely under env control would require both isolates from sexual partners to exhibit similar sensitivity to VCNT. The results obtained from four pairs of patients are compatible with this hypothesis. The disparate results obtained with 24 paired isolates may be explained as a function of the physiological state of the organism in vivo. For many organism...

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Prevalence of multiple antibiotic resistance in Neisseria gonorrhoeae.

Cited by 4 publications

References 17 publications

Transfer of Plasmid-Borne Beta-Lactamase in Neisseria gonorrhoeae

Transfer of Plasmid-Borne Beta-Lactamase in Neisseria gonorrhoeae

Auxotypes and antibacterial resistance to gonococci with differing susceptibilities to vancomycin.

Inhibition of gonococci by a selective medium: disparity between isolates from sexual partners.

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