Antimicrobial Resistance of Neisseria gonorrhoeae in Selected World Health Organization Southeast Asia Region Countries: An Overview

Prevalence and Antimicrobial Susceptibility Patterns of Neisseria gonorrhoeae among Suspected Patients Attending Private Clinics in Jimma, Ethiopia

BACKGROUND

In most African countries including Ethiopia, Neisseria gonorrhoeae infections were diagnosed clinically and its antibiotic susceptibility was rarely tested. This study aimed to determine the prevalence and antimicrobial susceptibility patterns of N. gonorrhoeae among suspected patients attending private clinics in Jimma, Ethiopia.

METHODS

Institution-based cross-sectional study was conducted to determine the prevalence and antimicrobial susceptibility pattern of N. gonorrhoeae isolated from urogenital specimens. Urogenital samples were collected aseptically and then transported using Amie's transport media and processed in a microbiology laboratory following the standard protocol.

RESULTS

Of the total 315 samples examined, 31 (9.8%) were confirmed to have gonococcal infection. Of these, 30 (96.7%) were females. High proportion of culture confirmed cases (18 (12.5%)) were observed in the 20-24 age group. All of the identified organisms were susceptible to ceftriaxone and had high resistance to penicillin (80.6%) and tetracycline (54.8%).

CONCLUSION

The prevalence of gonococcal infection is high. In the current study, participants who have no information about sexually transmitted infection were more likely to be infected by N. gonorrhoeae. According to our study, ciprofloxacin is effective against gonococcal infection.

Microbial Infections and Antimicrobial Resistance in Nepal: Current Trends and Recommendations

Antimicrobial resistance is a life threatening challenges to the world. Most of the well-known antibiotics are currently ineffective to several microbial diseases. Ampicillin, metronidazole, amoxicillin, cotrimoxazole, chloramphenicol, ciprofloxacin, nalidixic acid, gentamicin, and ceftazidime are common antibiotics whose resistance pattern has been elevated in recent years. The rise and dissemination of resistant bacteria has contributed in increasing cases of antimicrobial resistance. Multi-drug Resistant (MDR) organism such as Staphylococcus aureus, Pseudomionas aeruginosa, Escherchia coli, and Mycobacterium tuberculosis are principal problems for public health and stakeholders. Globally, issues of antimicrobial resistance are major concern. In the context of Nepal, insufficient surveillance system, lack of appropriate policy, and poor publications regarding the use of antibiotics and its resistance pattern has misled to depict exact scenario of antimicrobial resistance. This mini-review presents current trends of antibiotic use and its resistance pattern in Nepal. In addition, global progression of antibiotic discovery and its resistance has been covered as well. Furthermore, use of antibiotics and possible ways on improvement of effectiveness have been discussed.

Rising trend of antimicrobial resistance among Neisseria gonorrhoeae isolates and the emergence of N. gonorrhoeae isolate with decreased susceptibility to ceftriaxone

CONTEXT

Gonorrhoea is one of the most common sexually transmitted infections (STI) in developing countries and is a global health problem.

AIMS

To analyze the trend of antimicrobial susceptibility of Neisseria gonorrhoeae isolates over the years, in a tertiary care hospital of North India.

SETTINGS AND DESIGN

The study population comprised males with urethritis and females with endocervicitis attending STI clinic of our hospital.

MATERIALS AND METHODS

In our STI laboratory, all gonococcal isolates are subjected to antimicrobial susceptibility testing by disc diffusion method as per CLSI guidelines. β-Lactamase production is determined by chromogenic cephalosporin test. Minimum Inhibitory Concentration (MIC) for ceftriaxone is determined by E-test.

STATISTICAL ANALYSIS USED

Data were expressed as percentages. The differences in percentages were tested for statistical significance by using χ2 test and P values were determined.

RESULTS

The percentage of penicillinase producing N. gonorrhoeae (PPNG) increased from 8% in 1995-96 to 20% in 2004-05 and 88% in 2011-2013. Quinolone-resistant N. gonorrhoeae (QRNG) showed a significant increase from 12% in 1995-96 to 98.3% in 2004-05, while 84% isolates were found to be QRNG by 2011-2013. In January 2013 we detected our first gonococcal isolate with decreased susceptibility to third-generation cephalosporins; Ceftriaxone, Cefixime and Cefpodoxime (MIC for ceftriaxone = 0.19 μg/ml).

CONCLUSIONS

The results of our study highlighted an alarming increase in the percentage of PPNG and QRNG strains over the years. Emergence of N. gonorrhoeae isolates with decreased susceptibility to third-generation cephalosporins is a cause of concern and thus emphasises the importance of antimicrobial susceptibility testing.

Trends of resistance to antimicrobials recommended currently and in the past for management of gonorrhea in the Apex STD center in India and comparison of antimicrobial resistance profile between 2002-2006 and 2007-2012

BACKGROUND

Antimicrobial resistance in Neisseria gonorrhoeae jeopardizes public health and continues to spread out to currently recommended and older antimicrobial agents. Antimicrobial resistance (AMR) surveillance provides essential clues toward the modification of treatment guidelines. The aim of the study was to determine gonococcal AMR profile and trends between 2007 and 2012 and to evaluate any change in AMR profile in comparison with published trends in 2002 to 2006.

METHODS

Antimicrobial susceptibility testing of 261 N. gonorrhoeae isolates from consecutive patients between 2007 and 2012 was determined for penicillin, tetracycline, ciprofloxacin, spectinomycin, extended-spectrum cephalosporins (ceftriaxone, cefixime, cefpodoxime) and azithromycin by the disk diffusion technique and the Etest method. P value was determined using χ test for comparisons of trends between the 2 periods.

RESULTS

In comparison of AMR trends between 2002-2006 and 2007-2012, penicillinase-producing N. gonorrhoeae, tetracycline-resistant N. gonorrhoeae, and ciprofloxacin-resistant strains increased significantly from 21.2% to 47.9% (P < 0.0001), 13.6% to 25.3% (P = 0.0002), and 78% to 89.7% (P = 0.0001), respectively. An insignificant increase from 2.4% to 4.2% (P > 0.05) in decreased susceptibility to ceftriaxone and 0.8% to 1.5% (P > 0.05) for azithromycin resistance was observed. All isolates were susceptible to spectinomycin over both the periods, except for one isolate in 2002.

CONCLUSIONS

The study highlights that there is a continuous increase in resistance to previously recommended antibiotics despite their disuse for treatment. The increase in number of strains with decreased susceptibility to extended-spectrum cephalosporins and azithromycin resistance, currently recommended for management of gonorrhea, is of serious concern. These trends should be monitored continuously to change antibiotic policy.

Potent and rapid antigonococcal activity of the venom peptide BmKn2 and its derivatives against different Maldi biotype of multidrug-resistant Neisseria gonorrhoeae

The emergence of multidrug-resistant strains of Neisseria gonorrhoeae constitutes a serious threat to public health and necessitates the discovery of new types of antimicrobial agents. Among the 18 clinical isolates of N. gonorrhoeae with susceptible to spectinomycin, ceftriaxone and cefixime, 14 isolates were resistance to penicillin, tetracycline and ciprofloxacin, while 2 isolates were susceptible to tetracycline and another was penicillin intermediate isolate. Significant differences between laboratory strain and multidrug resistant strains were revealed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling and bioinformatics examination using the MALDI BioTyper software. However, Maldi Biotyper was not successfully separated ciprofloxacin-penicillin resistance and ciprofloxacin-tetracycline resistance from ciprofloxacin-penicillin-tetracycline resistant N. gonorrhoeae isolates. BmKn2 is a basic, alpha-helical peptide with no disulfide-bridge venom peptides that was first isolated from Buthus martensii Kasch. A panel of BmKn2 scorpion venom peptide and its derivatives of varying length and characteristics were synthesized chemically and evaluated for their ability to inhibit the growth of clinical N. gonorrhoeae isolates. Synthetic BmKn2 displayed potent activity against 18 clinical isolates of N. gonorrhoeae with MIC50 values of 6.9-27.6 μM. BmKn2 exerted its antibacterial activity via a bactericidal mechanism. Cyclic BmKn1 did not show antigonococcal activity. Decreasing the cationicity and helix percentage at the C-terminus of BmKn2 reduced the potency against N. gonorrhoeae. Taken together, the BmKn1 peptide can be developed as a topical therapeutic agent for treating multidrug-resistant strains of N. gonorrhoeae infections.

Antibiotic resistance inNeisseria gonorrhoeaeis diminishing available treatment options for gonorrhea: some possible remedies

Gonorrhea is essentially out of control in many settings and high disease rates are coupled with the spread of multiresistant gonococci. Increases in quinolone resistance have followed loss of the penicillins and tetracyclines as useful treatments. Decreasing susceptibility to third-generation cephalosporins is also reported. Over-reliance on antibiotic treatment as a disease control measure in settings with high disease rates and poor control of antibiotic usage is a significant contributor to the antimicrobial resistance reported. Conversely, containment of resistance is more likely to be achieved when combined with disease control principles shown to be effective. However, until a higher priority is given to funding for sexually transmitted diseases, this prospect is unlikely to eventuate and the possibility of untreatable gonorrhea becomes more real.

Antimicrobial susceptibility and genetic characteristics of Neisseria gonorrhoeae isolates from India, Pakistan and Bhutan in 2007-2011

BACKGROUND

Knowledge on antimicrobial drug resistance and genetic characteristics of Neisseria gonorrhoeae isolates circulating in India, Pakistan, and Bhutan is sorely lacking. In this paper, we describe the prevalence of antimicrobial resistance and molecular characteristics of N. gonorrhoeae isolates from India, Pakistan, and Bhutan in 2007-2011.

METHODS

Antimicrobial susceptibility and β-lactamase production were tested for 65 N. gonorrhoeae isolates from India (n=40), Pakistan (n=18) and Bhutan (n=7) using Etest methodology (eight antimicrobials) and nitrocefin solution, respectively. Resistance determinants, i.e. penA, mtrR, porB1b, gyrA, and parC, were sequenced. N. gonorrhoeae multiantigen sequence typing (NG-MAST) was performed for molecular epidemiology.

RESULTS

The highest resistance level was observed for ciprofloxacin (94%), followed by penicillin G (68%), erythromycin (62%), tetracycline (55%), and azithromycin (7.7%). All the isolates were susceptible to ceftriaxone, cefixime, and spectinomycin. Thirty-four (52%) of the isolates were producing β-lactamase. No penA mosaic alleles or A501-altered alleles of penicillin-binding protein 2 were identified. Forty-nine NG-MAST STs were identified, of which 42 STs have not been previously described worldwide.

CONCLUSIONS

Based on this study, ceftriaxone, cefixime, and spectinomycin can be used as an empirical first-line therapy for gonorrhoea in India, Pakistan, and Bhutan, whereas ciprofloxacin, penicillin G, tetracycline, erythromycin, and azithromycin should not be. It is imperative to strengthen the laboratory infrastructure in this region, as well as to expand the phenotypic and genetic surveillance of antimicrobial resistance, emergence of new resistance, particularly, to extended-spectrum cephalosporins, and molecular epidemiology.

Etiology and determinants of sexually transmitted infections in Karnataka state, south India

BACKGROUND

Syndromic case management remains the cornerstone for STI (sexually transmitted infection) treatment in many countries. We undertook this study to better understand the etiology of STIs in adults in south India and to inform STI management guidelines.

METHODS

Adult males and females presenting with genital complaints were recruited from clinics in Karnataka state, south India. A questionnaire was administered, physical examination performed, and blood collected for herpes simplex virus-type 2 (HSV-2) and syphilis serology. Men with urethral discharge (UD) and women with vaginal discharge were tested for Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV). Vaginal swabs were also tested for bacterial vaginosis and yeast infection. Participants with genital ulcers were tested for Treponema pallidum (TP), Haemophilus ducreyi (HD), and HSV-2. human immunodeficiency virus (HIV) testing was offered to all individuals.

RESULTS

There were 401 male and 412 female participants, and rates of HIV infection were high (men, 17%; women, 15%). HSV-2 was significantly associated with HIV in men and women. Among men with the complaint of UD, NG was identified in 35%, CT in 10.5%, and TV in 8.5%. Very little NG or CT was detected among women with vaginal discharge. However, bacterial vaginosis was identified in approximately 40% of women, with significant amounts of TV and Candida also detected. HSV-2 was the most commonly identified pathogen among participants with genital ulcer disease, and the clinical distinction of herpetic versus nonherpetic lesions was not helpful.

CONCLUSIONS

Current STI management guidelines should be reevaluated in south India. Consideration should be given to treating all persons with GUD for both HSV-2 and syphilis, and to adding initial treatment for TV for men with UD in areas of high background prevalence of HSV-2 and TV, respectively. This population is at high risk for HIV, and should be counseled and tested appropriately.

Meeting the public health challenge of multidrug- and extensively drug-resistant Neisseria gonorrhoeae

Globally, antimicrobial resistance (AMR) in Neisseria gonorrhoeae is increasing in prevalence, both within and across antibiotic classes, including extended-spectrum cephalosporins, raising concerns that gonorrhea may become untreatable in certain circumstances. The AMR surveillance that is essential to optimize standard treatments is often lacking or of poor quality in countries with high disease rates. Recent initiatives by the WHO to enhance global AMR surveillance that focus on multidrug- and extensively drug-resistant N. gonorrhoeae through revision of surveillance standards and use of a new panel of N. gonorrhoeae control strains are described. Keys to meeting these new challenges posed by gonococcal AMR remain the reduction in global burden of gonorrhea combined with implementation of wider strategies for general AMR control, and better understanding of mechanisms of emergence and spread of AMR.

The use of cephalosporins for gonorrhea: the impending problem of resistance

Gonorrhea remains an important clinical and public health problem throughout the world. Gonococcal infections have historically been diagnosed by Gram stain and culture but are increasingly diagnosed through nucleic acid tests, thereby eliminating the opportunity for antimicrobial susceptibility testing. Gonococcal infections are typically treated with single-dose therapy with an agent found to cure > 95% of cases. Unfortunately, the gonococcus has repeatedly developed resistance to antimicrobials including sulfonamides, penicillin, tetracyclines and fluoroquinolones. This has now left third-generation cephalosporins as the lone class of antimicrobials recommended as first-line therapy for gonorrhea in some regions. However, resistance to oral third-generation cephalosporins has emerged and spread in Asia, Australia and elsewhere. The mechanism of this resistance seems to be associated with a mosaic penicillin binding protein (penA) in addition to other chromosomal mutations previously found to confer resistance to beta-lactam antimicrobials (ponA, mtrR, penB, pilQ). Few good options exist or are in development for treating cephalosporin-resistant isolates, as most have had multidrug resistance. Preventing the spread of resistant isolates will depend on ambitious antimicrobial management programs, strengthening and expanding surveillance networks, and through effective sexually transmitted disease control and prevention.

Four different integrative recombination events involved in the mobilization of the gonococcal 5.2 kb beta-lactamase plasmid pSJ5.2 in Escherichia coli

We identified and characterized four different recombination mechanisms involved in the cointegrative transfer of the Neisseria gonorrhoeae beta-lactamase plasmid pSJ5.2 by the gonococcal 41 kb tet(M) and the Gram negative self-transmissible plasmids N3 and R64 drd-33 using an Escherichia colirecA-background. Mobilization of pSJ5.2 by the tet(M) plasmid occurred by cointegration through a replicative transposition of two IS1 elements inserted upstream from the beta-lactamase gene of pSJ5.2 and creating a IS1::beta-lactamase hybrid promoter. Two types of recombinational events occurred within the 1.8 kb BamH1-HindIII fragment of pSJ5.2 with the N3 and R64 plasmids. A non-homologous recombination was found at coordinates 1817 and 2849 of pSJ5.2 with sequences from R64. A non-homologous recombination combined with an IS26-mediated one-ended transposition was found at coordinates 1817 and 3010 of pSJ5.2 with N3. In both recombinational events, a deletion of over 1 kb of pSJ5.2 occurred. The fourth recombination event was detected in the 1.0 kb BamH1-HindIII fragment of pSJ5.2 by homologous recombination between DNA from the truncated Tn3 resolvase gene of pSJ5.2 and the resolvase sequences from R64 and N3.

Reproductive tract infections among women attending a gynecology outpatient department in Vientiane, Lao PDR

OBJECTIVES AND GOAL

To clinically and microbiologically identify reproductive tract infections (RTI), including sexually transmitted infections (STI), and to monitor the antibiotic susceptibility of Neisseria gonorrhoeae among women attending a gynecology outpatient department in Vientiane, Laos.

STUDY DESIGN

Clinical and laboratory-based cross-sectional study. Women aged 15 to 49 years underwent a pelvic examination, and specimens were taken for laboratory testing.

RESULTS

Of 1125 study participants, 82% clinically presented with an RTI syndrome. However, only 64% had an etiologically diagnosed RTI, including 11% with an STI. Endogenous infections were most prevalent (candidiasis 40%; bacterial vaginosis 25%), followed by STI [Chlamydia trachomatis 4.1%; N. gonorrhoeae (NG) and Trichomonas vaginalis, both 3.7%]. The 41 NG isolates showed 20% resistance to ciprofloxacin, 98% to penicillin, and complete to tetracycline.

CONCLUSIONS

High RTI/STI level combined with high NG resistance emphasizes that concurrent with syndromic case management, periodic evaluations of etiological diagnosis should be available to ensure adequacy of treatment algorithms and prescribed medications.

Behavior, Knowledge, Attitude, and Other Characteristics of Men Who Had Sex With Female Commercial Sex Workers in Kenya

We examined sociodemographic characteristics, knowledge, behavior, and attitude of men who had sex with commercial sex workers (CSWs) in Kenya. About 15% of the men had sex with CSWs. Men who had two or more partners, were away from home five or more times in the past year, and used condoms consistently with their last three partners were likely to have had sex with CSWs (odds ratio [OR] = 2.70, p = .000; OR = 1.43, p = .044; OR = 2.50, p = .000, respectively). Men with better knowledge of HIV/AIDS prevention methods were likely to have had sex with CSWs (OR = 1.62, p = .004). As expected, having had sex with CSWs was associated with higher risk of sexually transmitted infection (OR = 3.62, p = .000). This unexpected association between knowledge and behavior could be bidirectional or reverse causality. Nonetheless, knowledge in prevention has not been translated to practice and change in behavior. These processes require continuous efforts, including assertive campaigns on sexual practices and behaviors.

Changing trends of antimicrobial susceptibility patterns of Neisseria gonorrhoeae in India and the emergence of ceftriaxone less susceptible N. gonorrhoeae strains

OBJECTIVES

To monitor the trend of antimicrobial susceptibility of Neisseria gonorrhoeae isolates from 2002 to 2006 in New Delhi, India under the Gonococcal Antimicrobial Susceptibility Programme and to document the emergence of any new antimicrobial resistance.

METHODS

Antimicrobial susceptibility of 382 N. gonorrhoeae isolates from clinical cases in males and females to penicillin, tetracycline, ciprofloxacin, spectinomycin and ceftriaxone was determined by disc diffusion technique, using WHO reference strains as controls and WHO interpretative criteria. MICs were determined using Etests.

RESULTS

A significant increasing trend of penicillin and ciprofloxacin resistance up to 2003 and 2004, respectively, and subsequent decrease in resistant strains with a concomitant increase in less susceptible strains, was observed. Tetracycline-resistant N. gonorrhoeae increased significantly from 6.7% in 2002 to 22.9% in 2005. Only one isolate was resistant to spectinomycin and nine isolates were less susceptible to ceftriaxone, during this 5 year period. A substantial proportion (23.3%) of strains were multiresistant.

CONCLUSIONS

Emergence of ceftriaxone less susceptible N. gonorrhoeae isolates is a cause for concern, although treatment failure was not observed. An active, continuous and comprehensive programme for monitoring and surveillance of antimicrobial resistance needs to be established in many laboratories, and a search for new effective agents needs to be initiated to respond to the emergence of resistant isolates.

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.

Mobilization of the gonococcal 5.2 kb beta-lactamase plasmid pSJ5.2 into Escherichia coli by cointegration with several gram-conjugative plasmids

We report the mobilization by cointegration of the gonococcal 5.2 kb beta-lactamase plasmid pSJ5.2 in an Escherichia coli background. Transfer of pSJ5.2 was measured by filter mating assays with five different conjugative plasmids from Enterobacteriaceae and the gonococcal 41 kb tet(M). Plasmid pSJ5.2 was mobilized to E. coli at frequencies of 1.7x10(-6), 9.3x10(-8) and 2.7x10(-5) by the tet(M), R64 drd-33 and N3 conjugative plasmids, respectively. Mobilization of pSJ5.2 by the 41 kb tet(M) conjugative plasmid resulted in stable Amp(R) E. coli transconjugants consisting of pSJ5.2 plasmid with an insertion located in the 2.4 kb BamHI-BamHI fragment. Mobilization of pSJ5.2 by R64drd-33 and N3 conjugative plasmids involved stable cointegrates as detected by Southern Blot with a DIG-labelled PstI-digested pSJ5.2 probe. Restriction analysis of the R64::pSJ5.2 and N3::pSJ5.2 cointegrates and Southern Blot with the pSJ5.2 probe showed that cointegrates formed by deletion of DNA regions within the 1.8 kb BamHI-HindIII fragment of pSJ5.2. The plasmid thus appears to use multiple recombination mechanisms for cointegration with different conjugative plasmids. The complete nucleotide sequence of pSJ5.2 was determined, and will be a useful tool to further investigate the molecular mechanisms leading to its cointegrative transfer.

Fluoroquinolone-Resistant Neisseria gonorrhoeae in Bali, Indonesia: 2004

OBJECTIVES

In the mid-1990s, fluoroquinolones were introduced in Indonesia for the management of gonorrhea and are now part of the national recommended treatment guidelines. We recently documented introduction of ciprofloxacin-resistant Neisseria gonorrhoeae strains in female sex workers (FSWs) in Timika, Indonesia, 5 years after treating gonococcal cervicitis with ciprofloxacin and periodically monitoring antimicrobial susceptibility of isolates. To assess the importance of this observation, we determined antimicrobial susceptibilities and strain types of N. gonorrhoeae isolates from FSWs seen in a sexually transmitted infection (STI) clinic in Denpasar, Bali, Indonesia.

GOAL

The goal of this study was to determine antimicrobial susceptibilities and strain types among N. gonorrhoeae isolated from FSWs in Denpasar, Bali.

STUDY DESIGN

FSWs in Denpasar were screened for N. gonorrhoeae by standard culture. Endocervical isolates were frozen in Microbank tubes and sent to the University of California at San Francisco on dry ice. Antimicrobial susceptibility testing using a Clinical Laboratory Standards Institute-recommended agar dilution method was performed at the Centers for Disease Control and Prevention. Isolates were characterized by beta-lactamase production, antimicrobial resistance phenotypes, and auxotype/serovar class.

RESULTS

One hundred forty-seven N. gonorrhoeae isolates were characterized. All isolates were highly resistant to tetracycline (minimum inhibitory concentration, >or=16.0 microg/mL): 117 (79.1%) were beta-lactamase-positive (PP-TR), 3 (2.0%) exhibited chromosomally mediated resistance to penicillin (PenR-TRNG), and 27 (18.2%) were susceptible to penicillin (TRNG). All isolates were susceptible to ceftriaxone, cefixime, and spectinomycin; lack of interpretive criteria do not allow interpretation of susceptibilities of cefoxitin, cefpodoxime, or azithromycin. Fifty-nine (40.1%) isolates were ciprofloxacin-resistant; 35 (59.3%) of the ciprofloxacin-resistant isolates exhibited high-level resistance to ciprofloxacin (Cip-HLR; minimum inhibitory concentration, >or=4.0 microg/mL of ciprofloxacin). Three (2.0%) isolates were intermediate to ciprofloxacin. Twenty-two strain types were identified among these isolates; small clusters were identified with 3 strain types.

CONCLUSIONS

N. gonorrhoeae isolates from FSWs in Denpasar were resistant to penicillin and tetracycline; 40.1% of the isolates were fluoroquinolone-resistant. With gonorrhea prevalence of 35% at this clinic (by nucleic acid amplified tests), ongoing surveillance for antimicrobial resistance will be needed to appropriately choose treatment for infections caused by these resistant organisms.

Travel and sexually transmitted infections

Increasing population mobility and increasing frequency and variety of sexually transmitted infections (STI) are closely linked around the globe. Although all mobile populations are at increased risk for acquiring STIs, international travelers are the focus of this review. Several aspects of travel such as opportunity, isolation, and the desire for unique experiences all enhance the likelihood of casual sexual experiences while abroad. The situational loss of inhibition of travel can be markedly enhanced by alcohol and drugs. Several of the most important elements of the complex interaction between travel and STIs are discussed.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolated in Jiangsu Province, China, with a focus on fluoroquinolone resistance

In this study, the phenotypic and genotypic resistance to fluoroquinolones in Neisseria gonorrhoeae isolated in Jiangsu Province, China, was analysed. In vitro susceptibility testing of eight antimicrobial agents, including ciprofloxacin and levofloxacin, against 95 clinical isolates was carried out. Detection of mutations in the gyrA and parC genes was performed by sequence analysis. The clinical isolates demonstrated 100 % resistance to ciprofloxacin and 98.9 % non-susceptibility to levofloxacin. All of the isolates were susceptible to cefotaxime and ceftriaxone. For cefepime, spectinomycin and tetracycline, 98.9, 94.7 and 1.1 % of the isolates were susceptible, respectively. None of the isolates was susceptible to penicillin. Five types based on gyrA mutations could be categorized among 54 isolates with seven different mutation sites found on their parC gene. Analysis of sequence results showed that the gyrA mutation Asp-95→Ala and the parC mutations Ser-87→Arg and Ser-87→Asn made a significant contribution to the resistance to fluoroquinolones, in addition to double mutations found in each gene. Therefore, the use of fluoroquinolones in the treatment of N. gonorrhoeae infections in Jiangsu Province is not recommended, while the use of third- and fourth-generation cephalosporins and spectinomycin is recommended.

Transformation of ciprofloxacin-resistant Neisseria gonorrhoeae gyrA, parE and porB1b genes

In several transformation experiments, we have shown that introduction of an alteration in GyrA at position 95 of a ciprofloxacin-susceptible Neisseria gonorrhoeae strain (minimum inhibitory concentration (MIC) 0.008 mg/L) increases the MIC to 0.064 mg/L. Two alterations (positions 91 and 95) increase the MIC to 0.125-0.25 mg/L. Transformants with ciprofloxacin MICs of 0.5-16 mg/L were obtained from a moderately ciprofloxacin-resistant strain (MIC 0.25 mg/L). These transformants had alterations in the gene for PorB1b and probably other genes. In one transformant, an alteration in ParE was also introduced, which probably contributed to ciprofloxacin resistance. The ciprofloxacin-resistant transformants had the donor porB1b sequence, and most of them also had altered serovars. We conclude that alterations in N. gonorrhoeae PorB1b could be involved in ciprofloxacin resistance.

Molecular epidemiology of recently emergent ciprofloxacin-resistant Neisseria gonorrhoeae in South Africa

OBJECTIVES

Syndromic management guidelines for male urethritis syndrome and female discharge syndrome (nonpregnant) in South Africa advocate the use of ciprofloxacin for potential infection with Neisseria gonorrhoeae. In 2003, reports of clinical failure of gonorrhea following ciprofloxacin treatment prompted a clinic-based surveillance to detect the presence of resistant isolates.

STUDY

Urethral samples for the isolation of N gonorrhoeae were obtained from consecutive male patients with urethral discharge attending the largest sexually transmitted disease clinic in KwaZuluNatal. Molecular typing of isolates was performed by means of N gonorrhoeae multiantigen sequence typing (NG-MAST).

RESULTS

Of 139 isolates, 31 (22%) were resistant to ciprofloxacin (minimum inhibitory concentration >or=1 mg/l). NG-MAST revealed novel, as well as previously described, sequence types (ST). The largest cluster of our isolates belonged to ST 217. This ST has been reported among ciprofloxacin-resistant isolates from Europe.

CONCLUSION

: The results underscore the urgency of review of the current treatment guidelines for discharge disease in KwaZuluNatal.

Vaccination of mice with gonococcal TbpB expressed in vivo from Venezuelan equine encephalitis viral replicon particles

We investigated the immunogenicity of gonococcal transferrin binding protein B (TbpB) expressed with and without a eukaryotic secretion signal from a nonpropagating Venezuelan equine encephalitis virus replicon particle (VRP) delivery system. TbpB was successfully expressed in baby hamster kidney (BHK) cells, and the presence of the eukaryotic secretion signal not only apparently increased the protein's expression but also allowed for extracellular localization and glycosylation. Mice immunized with VRPs produced significant amounts of serum antibody although less than the amounts produced by mice immunized with recombinant protein. The response of mice immunized with VRPs encoding TbpB was consistently more Th1 biased than the response of mice immunized with recombinant protein alone. Boosting with recombinant protein following immunization with TbpB VRPs resulted in higher specific-antibody levels without altering the Th1/Th2 bias. Most of the immunization groups produced significant specific antibody binding to the intact surface of the homologous Neisseria gonorrhoeae strain. Immunization with TbpB VRPs without a eukaryotic secretion signal generated no measurable specific antibodies on the genital mucosal surface, but inclusion of a eukaryotic secretion signal or boosting with recombinant protein resulted in specific immunoglobulin G (IgG) and IgA in mucosal secretions after TbpB VRP immunization. The TbpB VRP system has potential for an N. gonorrhoeae vaccine.

Analysis of mutations within multiple genes associated with resistance in a clinical isolate of Neisseria gonorrhoeae with reduced ceftriaxone susceptibility that shows a multidrug-resistant phenotype

A Neisseria gonorrhoeae strain with a reduced susceptibility to ceftriaxone (minimum inhibitory concentration (MIC) = 0.5 microg/mL) was isolated among 398 clinical isolates obtained from 2000-2001 in Fukuoka City, Japan. The N. gonorrhoeae strain was negative for penicillinase production but it showed multidrug resistance against penicillin (MIC = 8 microg/mL), tetracycline (MIC = 4 microg/mL), azithromycin (MIC = 0.5 microg/mL) and ciprofloxacin (MIC = 16 microg/mL). The molecular mechanisms of the multidrug-resistant phenotype in this strain were analysed. Polymerase chain reaction and direct DNA sequencing were performed to identify mutations within the penA, ponA, mtrR, penB, gyrA and parC genes of the gonococcal strain, which thus explain the multidrug-resistant phenotype. The N. gonorrhoeae strain contained a significantly different sequence of the penA gene from that of the ceftriaxone-susceptible strains. Some regions of the transpeptidase domain within this penA gene were closely similar to those found in other Neisseria species such as Neisseria subflava, Neisseria flavescens or Neisseria perflava/sicca. This strain also included a ponA mutation that is associated with high-level resistance to penicillin, mtrR mutations that mediate overexpression of the MtrCDE efflux pump responsible for resistance to hydrophobic agents such as azithromycin, and penB mutations that reduce porin permeability to hydrophilic agents such as tetracycline. Moreover, this strain contained gyrA and parC mutations that confer high-level resistance to ciprofloxacin. These results indicate the emergence of a N. gonorrhoeae strain with reduced susceptibility to ceftriaxone, which also showed a multidrug-resistant phenotype that can be explained by the presence of multiple loci mutations associated with antibiotic resistance.