Increased tetracycline resistance in gonococci in The Netherlands

Surveillance of antibiotic resistance in Neisseria gonorrhoeae in The Netherlands, 1977-95

OBJECTIVE

To evaluate the prevalence and epidemiology of penicillinase producing Neisseria gonorrhoeae (PPNG) and tetracycline resistant N gonorrhoeae (TRNG) in the period 1977-95 in the Netherlands. To compare auxotypes, serovars, and antibiograms of PPNG, non-PPNG, and TRNG. To identify determinants in patient characteristics for the epidemic spread of TRNG/PPNG.

METHODS

With respect to the national gonococcal surveillance all PPNG isolates from 30 laboratories over the country in 1977-90 and all gonococcal isolates from five sentinel laboratories (during 1 month per quarter) in 1991-5 were collected. Isolates were auxotyped and serotyped, the susceptibility for various antibiotics was tested and plasmid contents were evaluated. Additional data on PPNG infected individuals were collected retrospectively during a microepidemic of TRNG/PPNG. Univariate and multivariate analyses were performed to identify risk factors for TRNG/PPNG infections.

RESULTS

In 1995 an overall high prevalence of PPNG infection (27%) and TRNG among PPNG infection (24%) was found in the Netherlands. Importantly, PPNG were found to have higher MICs for ceftriaxone and ciprofloxacin than non-PPNG; clinically relevant resistance to these antibiotics (or related agents) may emerge first among these strains. The observed diversity of strains (123 auxo/serovar classes since 1988) indicates a continuous introduction of new strains into the community. The epidemic increase of TRNG/PPNG was mainly caused by A/S classes NR/1B-6, PRO/1A-3, and PRO/1A-6, suggesting a clonal spread of a few strains; the rapid spread was associated with transmission in high risk individuals (that is, prostitutes and their clients).

CONCLUSION

The prevalence of PPNG in the Netherlands remains high and reduced sensitivity to other antimicrobials was detected among the PPNG strains. This underlines the necessity for a continuous national surveillance of resistance in gonococci including limited epidemiological information.

Epidemic spread of plasmid-mediated tetracycline resistant Neisseria gonorrhoeae in Zaire

A cohort of 650 prostitutes from Kinshasa, Zaire, was followed at monthly intervals for sexually transmitted diseases as part of an HIV intervention project. Neisseria gonorrhoeae isolates, obtained during a period of 30 months, were auxotyped, serotyped and tested for antimicrobial susceptibility. Among 1085 gonococcal isolates tested, 725 (67%) produced beta-lactamase (PPNG) and 323 (30%) showed plasmid-mediated resistance to tetracyline (TRNG). Over time, the prevalence of PPNG varied between 60 and 73%, while the level of TRNG increased from 11 to 45%.

A controlled trial of povidone-iodine as prophylaxis against ophthalmia neonatorum

BACKGROUND

Neonatal conjunctivitis (ophthalmia neonatorum) continues to cause blindness because the agents used prophylactically to prevent this condition are not completely effective and are not widely available in many parts of the world. Povidone-iodine ophthalmic solution is an effective antibacterial agent with broad antibacterial and antiviral activity to which no bacteria are known to be resistant, and it is far less expensive and less toxic than the agents currently used to prevent neonatal conjunctivitis.

METHODS

We conducted a masked, prospective trial involving 3117 infants born over a period of 30 months in a hospital in Kenya. Shortly after birth each infant received a 2.5 percent solution of povidone-iodine (n = 1076), a 1 percent solution of silver nitrate (n = 929), or 0.5 percent erythromycin ointment (n = 1112) in both eyes. Randomization was achieved by rotating the three medications after each was used for a week.

RESULTS

Of the neonates treated with povidone-iodine, 13.1 percent had infectious conjunctivitis, as compared with 17.5 percent of those treated with silver nitrate (P < 0.001) and 15.2 percent of those treated with erythromycin (P = 0.01). Povidone-iodine was more effective against Chlamydia trachomatis than was silver nitrate (P < 0.001) or erythromycin (P = 0.008). There were 104 cases of noninfectious conjunctivitis (9.7 percent) in the povidone-iodine group, as compared with 129 in the silver nitrate group (13.9 percent, P < 0.001) and 148 in the erythromycin group (13.3 percent, P = 0.004). Many cases of noninfectious conjunctivitis were probably due to a toxic reaction to the treatment itself. The incidence of Neisseria gonorrhoeae and Staphylococcus aureus infections was similar in the three groups.

CONCLUSIONS

A 2.5 percent ophthalmic solution of povidone-iodine as prophylaxis against ophthalmia neonatorum is more effective than treatment with silver nitrate or erythromycin, and it is less toxic and costs less.

Povidone-iodine for ophthalmia neonatorum prophylaxis

PURPOSE

The agents currently used to prevent ophthalmia neonatorum are less than optimal, with reports indicating evidence of bacterial resistance, ineffectiveness, and toxicity. Povidone-iodine ophthalmic solution, which has been shown to be effective in the preoperative preparation of the eye, generates no resistance, is an effective antimicrobial agent, and has low toxicity. We evaluated the effectiveness and safety of povidone-iodine for ophthalmia neonatorum prophylaxis.

METHODS

A bacterial culture was taken from the conjunctiva of each eye of 100 infants within 30 minutes of birth. A drop of 2.5% povidone-iodine solution was then placed on one eye, while the other eye received either one drop of silver nitrate 1% ophthalmic solution or 0.5% erythromycin ointment. Conjunctival bacterial cultures were again taken two to four hours after birth. At each culture and at 24 hours after birth, the eyes were examined for toxic changes. To measure the effectiveness of the medications, the number of bacterial colony-forming units and species from each culture was compared.

RESULTS

All three agents significantly reduced the number of colony-forming units, but povidone-iodine caused the most significant decrease. The number of species was reduced significantly by povidone-iodine (P = .00051) and silver nitrate (P = .007), with povidone-iodine yielding the most significant decrease. Erythromycin did not significantly reduce the number of species. Silver nitrate demonstrated more ocular toxicity at the 24-hour determination point than did either of the other two medications (P < .001).

CONCLUSIONS

Povidone-iodine 2.5% ophthalmic solution is an effective antibacterial agent on the conjunctiva of newborns and causes less toxicity than silver nitrate.

Sexually transmitted diseases and travelers

Sexually active travelers are at risk for a variety of STDs, including traditional venereal infections such as gonorrhea, chlamydial urethritis, syphilis, chancroid, and herpes simplex infection. More recently, hepatitis B, hepatitis C, and HIV-1 have also been described. Risk varies depending on the geographic area of travel and the type of sexual contact. Physicians should be aware of the prevalence of antimicrobial resistance of N. gonorrhoeae and H. ducreyi because this will affect empiric antibiotic therapy. Prevention should focus on proper and consistent usage of barrier contraceptives.

Antimicrobial susceptibility of Neisseria gonorrhoeae in Zaire: high level plasmid-mediated tetracycline resistance in central Africa

OBJECTIVE

To determine the in vitro antimicrobial susceptibility of gonococcal strains isolated in 1988 among female prostitutes in Kinshasa, Zaire and to characterise strains with high level tetracycline resistance.

METHODS

Minimal inhibitory concentrations of 8 antimicrobials were measured by agar dilution technique. Plasmid-profiles and serovars were determined.

RESULTS

Two hundred and thirteen strains of Neisseria gonorrhoeae were tested of which 59% were beta-lactamase producers and an additional 21% showed intermediate or chromosomal resistance to penicillin (MIC = 0.5-8 mg/l). Eleven percent of the strains were resistant to the combination sulfamethoxazole-trimethoprim (MIC greater than 8 mg/l) and 57% of the isolates showed decreased susceptibility to thiamphenicol (MIC = 1-4 mg/l). All strains were sensitive to spectinomycin, norfloxacin and ceftriaxone and moderately sensitive to kanamycin. Chromosomal resistance to tetracycline was observed in 45% of strains (MIC = 2-8 mg/l). Ten percent were highly resistant to tetracycline (TRNG, MIC = 16-128 mg/l) and were shown to carry a plasmid borne Tet M determinant; such strains were not found in Kinshasa in 1985. TRNG belonged to 4 different serovars, which were also the dominant serovars in non-TRNG.

CONCLUSION

These findings illustrate the high frequency of multiresistant gonococci in Zaire and suggest that high level tetracycline resistant strains of N. gonorrhoeae have become endemic in Central Africa.