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

BMC Infectious Diseases (Impact Factor: 2.56). 01/2013; 13(1):35. DOI: 10.1186/1471-2334-13-35
Source: PubMed

ABSTRACT 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 beta-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 beta-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.

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    ABSTRACT: Background Evolving gonococcal antimicrobial resistance (AMR) poses a serious threat to public health. The aim of this study was to: update antimicrobial susceptibility data of Neisseria gonorrhoeae recently isolated in Nanjing, China and identify specific deteminants of antimicrobial resistance and gentoypes of isolates with decreased sensitivity to ceftriaxone.Methods334¿N. gonorrhoeae isolates were collected consecutively from symptomatic men attending the Nanjing STD Clinic between April 2011 and December 2012. The minimum inhibitory concentrations (MICs) for penicillin, tetracycline, ciprofloxacin, spectinomycin and ceftriaxone were determined by agar plate dilution for each isolate. Penicillinase-producing N. gonorrhoeae (PPNG) and tetracycline-resistant N. gonorrhoeae (TRNG) were examined and typed for ß-lactamase and tetM encoding plasmids respectively. Isolates that displayed elevated MICs to ceftriaxone (MIC ¿0.125 mg/L) were also tested for mutations in penA, mtrR, porB1b, ponA and pilQ genes and characterized by Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST).Results98.8% (330/334) of N. gonorrhoeae isolates were resistant to ciprofloxacin; 97.9% (327/334) to tetracycline and 67.7% (226/334) to penicillin. All isolates were susceptible to ceftriaxone (MIC ¿0.25 mg/L) and spectinomycin (MIC ¿32 mg/L). Plasmid mediated resistance was exhibited by 175/334 (52%) of isolates: 120/334 (36%) of isolates were PPNG and 104/334 (31%) were TRNG. 90.0% (108/120) of PPNG isolates carried the Asia type ß-lactamase encoding plasmid and 96% (100/104) of TRNG isolates carried the Dutch type tetM containing plasmid. Elevated MICs for ceftriaxone were present in 15 (4.5%) isolates; multiple mutations were found in penA, mtrR, porB1b and ponA genes. The 15 isolates were distributed into diverse NG-MAST sequence types; four different non-mosaic penA alleles were identified, including one new type.Conclusions N. gonorrhoeae isolates in Nanjing generally retained similar antimicrobial resistance patterns to isolates obtained five years ago. Fluctuations in resistance plasmid profiles imply that genetic exchange among gonococcal strains is ongoing and is frequent. Ceftriaxone and spectinomycin remain treatments of choice of gonorrhea in Nanjing, however, decreased susceptibility to ceftriaxone and rising MICs for spectinomycin of N. gonorrhoeae isolates underscore the importance of maintaining surveillance for AMR (both phenotypic and genotypic).
    BMC Infectious Diseases 11/2014; 14(1):622. DOI:10.1186/s12879-014-0622-0 · 2.56 Impact Factor
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    ABSTRACT: Background Although sophisticated methodologies are available, the use of endpoint polymerase chain reaction (PCR) to detect 16S rDNA genes remains a good approach for estimating the incidence and prevalence of specific infections and for monitoring infections. Considering the importance of the early diagnosis of sexually transmitted infections (STIs), the development of a sensitive and affordable method for identifying pathogens in clinical samples is needed. Highly specific and efficient primers for a multiplex polymerase chain reaction (m-PCR) system were designed in silico to detect the 16S rDNA genes of four bacteria that cause genital infections, and the PCR method was developed. Methods The Genosensor Probe Designer (GPD) (version 1.0a) software was initially used to design highly specific and efficient primers for in-house m-PCR. Single-locus PCR reactions were performed and standardised, and then primers for each locus in turn were added individually in subsequent amplifications until m-PCR was achieved. Amplicons of the expected size were obtained from each of the four bacterial gene fragments. Finally, the analytical specificity and limits of detection were tested. Results Because they did not amplify any product from non-STI tested species, the primers were specific. The detection limits for the Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma hominis and Ureaplasma urealyticum primer sets were 5.12 × 105, 3.9 × 103, 61.19 × 106 and 6.37 × 105 copies of a DNA template, respectively. Conclusions The methodology designed and standardised here could be applied satisfactorily for the simultaneous or individual detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma hominis and Ureaplasma urealyticum. This method is at least as efficient as other previously described methods; however, this method is more affordable for low-income countries.
    BMC Research Notes 07/2014; 7(1):433. DOI:10.1186/1756-0500-7-433
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    ABSTRACT: Neisseria gonorrhoeae is the second most sexually transmitted diseases agents in developing countries. Antimicrobial resistance strains have created serious health concern. The aim of this study was to determine the frequency of endocervical gonococcal infection and antimicrobial susceptibility of N. gonorrhoeae in Kashan, Iran. In this study, 294 endocervical swabs were collected from married women referred to the obstetrics and gynecology clinics in Kashan from December 2012 to May 2013. The samples were cultured in modified Thayer Martin in 37°C with 5-10% CO2 for 72 hours. Gram staining, oxidase, catalase and carbohydrate utilization tests were used to identify the isolated species. All isolates were tested for their susceptibilities to antimicrobials using the Kirby Bauer-disk diffusion techniques. N. gonorrhoeae was detected in 2.38% of studied cases (95% confidence interval [CI] 1.5-3.26%). All isolates were resistance to ceftriaxone, penicillin G, ciprofloxacin, cefepime, and two isolate (28.5%) showed intermediate sensitivity to tetracycline. Continued monitoring of prevalence of N. gonorrhoeae is important for preventing the dissemination of this microorganism. The present study emphasizes the importance of surveillance of antimicrobial resistance of N. gonorrhoeae in order to manage the rate of resistant strains and to revise the treatment policies.
    06/2014; 6(3):194-7.

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