Increased ciprofloxacin resistance in gonococci isolated in Scotland

Update on the management of gonorrhea in adults in the United States

Gonorrhea, the second most commonly reported notifiable disease, is an important cause of cervicitis, urethritis, and pelvic inflammatory disease. The selection of appropriate therapy for gonorrhea (i.e., safe, highly effective, single dose, and affordable) is complicated by the ability of Neisseria gonorrhoeae to develop resistance to antimicrobial therapies. This article reviews the key questions and data that informed the 2006 gonorrhea treatment recommendations of the Centers for Disease Control and Prevention. Key areas addressed include the criteria used to select effective treatment for gonorrhea, the level of antimicrobial resistance at which changing treatment regimens is recommended, the epidemiology of resistance, and the use of quinolones, cephalosporins, and other classes of antimicrobials for the treatment of uncomplicated gonorrhea.

Rapid detection of fluoroquinolone resistance by isothermal chimeric primer-initiated amplification of nucleic acids from clinical isolates of Neisseria gonorrhoeae

To ensure a complete response to fluoroquinolone therapy against Neisseria gonorrhoeae infections, rapid susceptibility determinations are required. We assessed a new approach, an isothermal chimeric primer-initiated amplification of nucleic acids (ICAN)/hybrid-chromatography method to detect rapidly fluoroquinolone resistance in N. gonorrhoeae. Comparison of the amplification results with fluoroquinolone minimum inhibitory concentrations (MICs), which were determined by an agar dilution method, showed that the new method accurately determined fluoroquinolone resistance in all ciprofloxacin- and/or gatifloxacin-resistant isolates, but agreed with results based on MICs in only 6 of 8 (75.0%) ciprofloxacin-susceptible and 7 of 12 (58.3%) gatifloxacin-susceptible isolates. Our results suggest that this method can rapidly and reliably detect point mutations in the gyrA gene as well as fluoroquinolone resistance in resistant isolates of N. gonorrhoeae.

The use of fluoroquinolones in gonorrhoea: the increasing problem of resistance

The recent re-emergence of gonorrhoea in developed countries has been accompanied by the rise and spread of gonococcal resistance to the fluoroquinolones. In the 1980s fluoroquinolones were considered an important addition to the arsenal of agents used to treat gonorrhoea. They proved to be excellent drugs for this indication, including infections caused by penicillinase-producing and tetracycline-resistant strains of Neisseria gonorrhoeae. However, as gonococci have a well-recognised potential to develop resistance to antibiotics, the first reports of reduced susceptibility to fluoroquinolones appeared a few years after their introduction. Gonococcal resistance to fluoroquinolones is now well-established in the Far East, from where it has spread to Australia, Hawaii, California and Europe. In Africa and Latin America, gonococci continue to be susceptible to fluoroquinolones.

Alarming increase in ciprofloxacin- and penicillin-resistant Neisseria gonorrhoeae isolates in New Delhi, India

BACKGROUND

Resistance of ciprofloxacin has been reported in several regions of the world, including India. In India, ciprofloxacin is still being used as single-dose treatment for gonorrhea.

GOAL

The aim of the study was to determine the antimicrobial susceptibility of Neisseria gonorrhoeae isolates from patients with acute gonococcal urethritis in New Delhi.

STUDY DESIGN

By means of disc diffusion, we determined the susceptibility profiles of N gonorrhoeae isolates, determined the MICs of ciprofloxacin, penicillin, and ceftriaxone, and compared our data with previous findings.

RESULTS

On the basis of MIC values, 35.3% and 52.9% of strains were found to be resistant and less sensitive, respectively, to penicillin; 67.3% and 28.2% strains were observed to be resistant and less sensitive, respectively, to ciprofloxacin. Only one isolate (5.9%) was found to be less sensitive to ceftriaxone.

CONCLUSION

The significant increase in ciprofloxacin resistance in the current study indicates that resistance has developed under selective antibiotic pressure.

Gonorrhoea in London: usefulness of first line therapies

OBJECTIVES

To determine the true prevalence and patterns of resistance of Neisseria gonorrhoeae to antimicrobial agents used for therapy in London.

METHODS

A longitudinal study of a representative sample of isolates of N gonorrhoeae linked to demographic data of infected patients was undertaken. Isolates were collected from consecutive patients attending genitourinary medicine clinics in the North and South Thames regions of London during 3 months of each of 4 years, 1997-2000. Prevalence of plasmid mediated resistance to penicillin and chromosomally mediated resistance to penicillin and ciprofloxacin was determined by susceptibility testing. The association of antimicrobial resistance among gonococci with sexual orientation of the patient and country of acquisition of infection was determined.

RESULTS

Numbers of gonococcal isolates collected over the same time period between 1997-2000 have increased by 74%. Plasmid mediated resistance to penicillin was low but has risen above 5% in 2000. Chromosomal resistance to penicillin has fallen below the 5% level but total resistance to penicillin, plasmid and chromosomally mediated, was above 5% in all 4 years. The incidence of resistance and reduced susceptibility to the alternative therapeutic choice, ciprofloxacin, is low but numbers are increasing in each year. High level resistance, to both penicillin and ciprofloxacin, has generally been found among heterosexual men and is often acquired abroad. However, there is some evidence of a change to endemic spread in 2000.

CONCLUSIONS

This surveillance programme shows that the epidemiology of gonorrhoea in London is changing with increasing numbers and changing patterns of resistance. If gonorrhoea is to be controlled and targets set by the sexual health strategy are to be met, intervention with effective and appropriate antimicrobial agents is essential.

Update on Quinolone Resistance in Neisseria gonorrhoeae

Quinolones are widely used for treating gonococcal infections, typically in single-dose, oral regimens. However, in the 1990s, quinolone-resistant Neisseria gonorrhoeae emerged, potentially compromising the utility of this drug class. In the past year, these strains have widely disseminated, accounting for over half of isolates in parts of Southeast Asia. The molecular mechanism of resistance has been localized to multiple mutations in genes coding for the bacterial DNA gyrase and topoisomerase enzymes. These mutations accumulate until the minimum inhibitory concentration is 4.0 g/mL or more, which in clinical studies appears to be the threshold for clinical treatment failure. Quinolone-resistant N. gonorrhoeae is independent from other plasmid- and chromosomally-mediated resistance determinants; nearly all isolates to date have been sensitive to cephalosporins and spectinomycin. Nevertheless, designing public health strategies to contain quinolone-resistant N. gonorrhoeae will be difficult.

Surveillance of antibiotic resistance of Neisseria gonorrhoeae isolates in China, 1993-1998

BACKGROUND

The prevalence of sexually transmitted diseases (STDs) has been increasing in China since the 1980s. Because gonorrhea is the most frequently reported STD there, information on the antimicrobial susceptibility of Neisseria gonorrhoeae will aid in its control.

GOAL

To investigate the antimicrobial susceptibility of N gonorrhoeae isolates in China and to provide data for formulation of treatment guidelines and control policies.

METHODS

The agar dilution technique was used to determine antimicrobial susceptibility, and acidimetric method was used to test for penicillinase-producing N gonorrhoeae.

RESULTS

A total of 3186 gonococcal isolates were tested during the 6-year study period. The rate of resistance to penicillin was 66.70%; 8.14% of isolates were penicillinase-producing N gonorrhoeae. The percentage of tetracycline-resistant isolates was 92.03%, and that of highly tetracycline-resistant isolates was 4.65%. The rate of resistance to ciprofloxacin was also relatively high (34.25%). The rates of resistance to spectinomycin and ceftriaxone were 0.44% and 0.57%.

CONCLUSIONS

The gonococcal isolates in China are relatively highly resistant to penicillin, tetracycline, and ciprofloxacin, but most of them are still susceptible to spectinomycin and ceftriaxone. Standardized treatment of gonorrhea is needed to prevent further spread of resistant gonococcal strains.