Penicillinase-producing N. Gonorrhoeae Research Articles

Seven Years of Culture Collection of Neisseria gonorrhoeae: Antimicrobial Resistance and Molecular Epidemiology.

The emergence of Neisseria gonorrhoeae isolates displaying resistance to antimicrobials, in particular to ceftriaxone monotherapy or ceftriaxone plus azithromycin, represents a global public health concern. This study aimed to analyze the trend of antimicrobial resistance in a 7-year isolate collection retrospective analysis in Italy. Molecular typing on a subsample of gonococci was also included. A total of 1,810 culture-positive gonorrhea cases, collected from 2013 to 2019, were investigated by antimicrobial susceptibility, using gradient diffusion method, and by the N. gonorrhoeae multiantigen sequence typing (NG-MAST). The majority of infections occurred among men with urogenital infections and 57.9% of male patients were men who have sex with men. Overall, the cefixime resistance remained stable during the time. An increase of azithromycin resistance was observed until 2018 (26.5%) with a slight decrease in the last year. In 2019, gonococci showing azithromycin minimum inhibitory concentration above the EUCAST epidemiological cutoff value (ECOFF) accounted for 9.9%. Ciprofloxacin resistance and penicillinase-producing N. gonorrhoeae (PPNG) percentages increased reaching 79.1% and 18.7% in 2019, respectively. The most common sequence types identified were 5,441, 1,407, 6,360, and 5,624. The predominant genogroup (G) was the 1,407; moreover, a new genogroup G13070 was also detected. A variation in the antimicrobial resistance rates and high genetic variability were observed in this study. The main phenotypic and genotypic characteristics of N. gonorrhoeae isolates were described to monitor the spread of drug-resistant gonorrhea.

Antimicrobial Susceptibility Testing Patterns of Neisseria gonorrhoeae from Patients Attending Sexually Transmitted Infections Clinics in Six Regions in Tanzania.

Antimicrobial resistance (AMR) is global health threat that is on the increase, and it has been adversely affecting the proper management of sexually transmitted infections (STI). Data on antimicrobial susceptibility testing patterns of N. gonorrhoeae are limited in local settings. We determined in vitro antimicrobial susceptibility and phenotypic profiles of N. gonorrhoeae isolated from STI/Outpatient Department (OPD) clinics. Minimum Inhibitory Concentrations (MIC) (µg/mL) were determined using E-Test and agar dilution methods for previously and currently recommended antimicrobial agents. A total of 164 N. gonorrhoeae isolates from urethral discharge and endocervical swabs were tested. The prevalence of resistant N. gonorrhoeae to tetracycline, norfloxacin, penicillin and ciprofloxacin were 98.6%, 82.2%, 84.3% and 75.6%, respectively. None of the isolates was resistant to kanamycin. Penicillinase producing N. gonorrhoeae (PPNG) was found to be 73.7%, with 56.7% and 43.3% observed among isolates from women and men, respectively. Tetracycline resistant-N. gonorrhoeae (TRNG) was found to be 34.0%, and QRNG with HLR to ciprofloxacin was 79.9%. The overall MDR-NG was 79.9%, and XDR-NG was 3.6%. MIC50 and MIC90 were 4.0 and 8.0 and 2.0 and 4.0 µg/mL for ciprofloxacin and norfloxacin, respectively. Dendrograms showed that 44 phenotypic groups are associated with a high rate of AMR among high MDR-NG and moderate XDR-NG isolates. The predominant groups of quinolone-resistant N. gonorrhoeae (QRNG)+PPNG (34.7%) and QRNG+PPNG+TRNG (32.9%) were observed among the isolates having HLR to ciprofloxacin. We reported a high prevalence of AMR (>90%) to previously recommended antimicrobials used for the treatment of gonorrhoea. Multidrug resistant N. gonorrhoeae (MDR-NG) was highly reported, and extensively drug resistant (XDR-NG) has gradually increased to the currently recommended cephalosporins including ceftriaxone and cefixime. Heterogeneous groups of QRNG+PPNG+ and QRNG+PPNG+TRNG were highly resistant to penicillin, tetracycline, ciprofloxacin and norfloxacin. A surveillance program is imperative in the country to curb the spread of AMR.

Changing antimicrobial susceptibility and molecular characterisation of Neisseria gonorrhoeae isolates in Guangdong, China: in a background of rapidly rising epidemic

The prevalence of Neisseria gonorrhoeae infections has increased rapidly since 2015 in China. Antimicrobial resistance and molecular mobilisation in N. gonorrhoeae are two important factors driving this increasing prevalence. This study explored changes in antimicrobial susceptibility and molecular characteristics of N. gonorrhoeae collected in Guangdong, China (2013-2017). A total of 704 isolates were collected in two cities in Guangdong. MICs of major antimicrobials were determined. Penicillinase-producing N. gonorrhoeae (PPNG) and tetracycline-resistant N. gonorrhoeae (TRNG) were characterised, and N. gonorrhoeae multiantigen sequence typing (NG-MAST) was performed. High resistance to penicillin (68.2%), tetracycline (85.7%) and ciprofloxacin (98.2%) was observed. Spectinomycin, ceftriaxone and azithromycin appeared effective, with susceptibilities of 100%, 96.4% and 90.7%, respectively. Resistance to penicillin decreased significantly from 78.4% to 73.6% and to azithromycin from 11.9% to 3.7%. Total prevalence of PPNG, TRNG and PPNG/TRNG was 25.4%, 33.1% and 13.4%, respectively. Rates of PPNG decreased significantly from 37.3% to 23.9%, TRNG from 50.0% to 31.3%, and PPNG/TRNG from 23.5% to 11.7%. However, the ratio of African-type PPNG increased significantly (18.4% to 64.1%) compared with decreasing Asian-type PPNG (81.6% to 33.3%), and the ratio of American-type TRNG increased significantly (0% to 13.7%) compared with decreasing Dutch-type TRNG (100% to 86.3%). A total of 271 sequence types (STs) were identified by NG-MAST from 380 isolates collected in 2013, 2014 and 2017, with 145 novel STs. African-type PPNG is increasing and replacing Asian-type, and novel STs have emerged. Gonococcal isolates with new genotypes might contribute to the rising gonorrhoea epidemic in this area.

1489. Trends in Antimicrobial Resistance in N. gonorrhoeae Isolated in Korea During 2015–2017

BackgroundThe trends of antimicrobial resistance (AMR) and the molecular epidemiology of gonococcal strains were analyzed in Korean during 2015 to 2017.MethodsThe susceptibility tests of 187 N. gonorrhoeae isolates were investigated. The minimum inhibitory concentration (MIC) of N. gonorrhoeae isolates were determined by the agar dilution method. Penicillinase-producing N. gonorrhoeae (PPNG) and plasmid-mediated tetracycline-resistant N. gonorrhoeae (TRNG) were evaluated. Isolates were tested for mutations in penA and also genotyped using N. gonorrhoeae multi-antigen sequence typing (NG-MAST) to determine the molecular epidemiological characteristics of the isolates.ResultsThe rates of resistance to ceftriaxone (CRO) increased from 6.5% in 2015 to 13.4% in 2017. Azithromycin resistance was documented only in 1.1%, but 53.5% of isolates showed intermediate susceptibility. All isolates were susceptible to spectinomycin. However, none of isolates was susceptible to ciprofloxacin and penicillin (PEN) and 4.3% of isolates were susceptible to tetracycline. The PPNG and TRNG increased from 25.7% and 39.4% in 2015 to 47.8% and 81.5% in 2017, respectively. 74.7% of the extended-spectrum cephalosporins (ESCs)-resistant isolates contained the mosaic PBP2 X allele, which has been previously associated with ESC resistance including treatment failures. penA mosaic alleles X were found in 83.8% of all isolates that harbored decreased susceptibility to cefixime. Among the 16 N. gonorrhoeae isolates with decreased susceptibility to CRO, penA mosaic X allele was identified in the 11 isolates. The 189 N. gonorrhoeae isolates were assigned to 112 different NG-MASTs; seven sequence types (STs) were novel. The most common ST was 10,668 (16.1%), followed by ST15024 (7.1%). Two ST1407 strains have been isolated in 2015. Although ST1407 was known to display decreased susceptibility to ESCs or full resistance, they were susceptible for CRO (MIC = 0.06 μg/mL) and cefixime (MIC = 0.12 μg/mL).ConclusionThe recent emergence of ESC-resistant N. gonorrhoeae strains which was often associated with mutations in the penA gene is a major concern and enhanced AMR surveillance is necessary to prevent transmission of these strains.Disclosures All authors: No reported disclosures.

Surveillance of Antibiotic Susceptibility Patterns of Neisseria gonorrhoeae from 2013 to 2015 in Guangxi Province, China.

Neisseria gonorrhoeae is a sexually transmitted pathogen highly prevalent worldwide with an increasing trend of resistance to antimicrobial treatment. We conducted this study to trace the susceptibility of N. gonorrhoeae to penicillin (PC), spectinomycin (SPCM), ciprofloxacin (CPFX), azithromycin (AZM), cefixime (CFIX), and ceftriaxone (CTRX) in Guangxi province. In total, 303 N. gonorrhoeae isolates were obtained from patients infected with N. gonorrhoeae in 6 cities in Guangxi during 2013-2015, and the antibiotic susceptibility patterns were analyzed by an agar dilution assay. The results showed that N. gonorrhoeae was susceptible to treatment with cephalosporins, including CTRX (99.7% of isolates), CFIX (99%), SPCM (100%), and AZM (96.4%), and this is the first report of antibiotic susceptibility for AZM surveillance of N. gonorrhoeae in Guangxi. Penicillinase-producing N. gonorrhoeae (PPNG) isolates increased in prevalence from 37% in 2013 to 64% in 2015 (P = 0.068), and tetracycline-resistant N. gonorrhoeae (TRNG) prevalence increased from 23% in 2013 to 44% in 2015 (P = 0.071). High resistance of N. gonorrhoeae to PC was associated with infection in patients at ages 25 to 30 years (P ＜ 0.05), whereas PPNG positivity (P ＜ 0.01), and TRNG positivity were risk factors for CPFX resistance (P = 0.0407). Our study provides plausible evidence for therapeutic strategies and N. gonorrhoeae infection control and prevention in Guangxi, China.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from Hefei (2014\u20132015): genetic characteristics of antimicrobial resistance

BackgroundAntimicrobial resistance (AMR) and genetic determinants of resistance of N. gonorrhoeae isolates from Hefei, China, were characterized adding a breadth of information to the molecular epidemiology of gonococcal resistance in China.Methods126 N. gonorrhoeae isolates from a hospital clinic in Hefei, were collected between January, 2014, and November, 2015. The minimum inhibitory concentration (MIC) of N. gonorrhoeae isolates for seven antimicrobials were determined by the agar dilution method. Isolates were tested for mutations in penA and mtrR genes and 23S rRNA, and also genotyped using N. gonorrhoeae multi-antigen sequence typing (NG-MAST).ResultsAll N. gonorrhoeae isolates were resistant to ciprofloxacin; 81.7% (103/126) to tetracycline and 73.8% (93/126) to penicillin. 39.7% (50/126) of isolates were penicillinase producing N. gonorrhoeae (PPNG), 31.7% (40/126) were tetracycline resistant N. gonorrhoeae (TRNG) and 28.6% (36/126) were resistant to azithromycin. While not fully resistant to extended spectrum cephalosporins (ESCs), a total of 14 isolates (11.1%) displayed decreased susceptibility to ceftriaxone (MIC ≥ 0.125 mg/L, n = 10), cefixime (MIC ≥ 0. 25 mg/L, n = 1) or to both ESCs (n = 3). penA mosaic alleles XXXV were found in all isolates that harbored decreased susceptibility to cefixime, except for one. Four mutations were found in mtrR genes and mutations A2143G and C2599T were identified in 23S rRNA. No isolates were resistant to spectinomycin. Gonococcal isolates were distributed into diverse NG-MAST sequence types (STs); 86 separate STs were identified.ConclusionsN. gonorrhoeae isolates from Hefei during 2014–2015, displayed high levels of resistance to antimicrobials that had been recommended previously for treatment of gonorrhea, e.g., penicillin, tetracycline and ciprofloxacin. The prevalence of resistance to azithromycin was also high (28.6%). No isolates were found to be fully resistant to spectinomycin, ceftriaxone or cefixime; however, 11.1% isolates, overall, had decreased susceptibility to ESCs.

Molecular epidemiology of penicillinase-producing Neisseria gonorrhoeae isolates in France

ObjectivesCharacterizing the molecular epidemiology of antibiotic resistance is crucial for a better understanding of the evolution and spread of resistance in Neisseria gonorrhoeae. Here, we examine the molecular epidemiology of penicillinase-producing N. gonorrhoeae (PPNG) isolates in France. MethodsWe investigated 176 PPNG isolates collected between 2010 and 2012 by the National Reference Centre in France. Genotyping was performed using the NG-MAST technique, blaTEM genes were Sanger-sequenced, and plasmids were characterized by PCR-typing. ResultsWe revealed the existence of four major clusters representing about one-third of PPNG circulating in France. These clusters were related to ST1479 (18/176, 10.2%), to ST1582 (15/176, 8.5%), to ST8922 (10/176, 5.6%), and to ST1285 (9/176, 5.1%). Wild-type TEM-1 was identified in 151 (151/176, 85.8%) PPNG isolates, and TEM-1 variants were mostly represented by the M182T mutation (14/176, 8%), followed by P14S/L (8/176, 4.5%), G228S (2/176, 1.1%), and Q269K (1/176, 0.6%). The blaTEM genes were carried by African (157/176, 89.2%), Asian (13/176, 7.4%), and Toronto/Rio (6/176, 3.4%) plasmids. The M182T variants were found in various genetic backgrounds, whereas the P14S variants were disseminated clonally. The G228S and Q269K variants belong to one of the four major clusters of PPNG, which suggests a recent de novo emergence of these mutations. ConclusionsOur results show that approximately one-third of the penicillinase-producing N. gonorrhoeae isolates in France belong to one of four major clusters and that the spread of the different TEM variants is associated with distinct patterns of molecular epidemiology.

The prevalence and epidemiology of plasmid-mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates in Guangzhou, China, 2002-2012.

BackgroundGonococcal antimicrobial resistance is a global problem. Different resistance plasmids have emerged and spread among the isolates of Neisseria gonorrhoeae worldwide and in China. We conducted this study to monitor the plasmid-mediated penicillin and tetracycline resistance among N. gonorrhoeae isolates in Guangzhou from 2002 to 2012.MethodsConsecutive isolates of N. gonorrhoeae were collected from outpatients with gonorrhea attending the STD clinic in Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention. Penicillinase-producing N. gonorrhoeae (PPNG) isolates were analyzed by the paper acidometric method. Plasmid-mediated resistance to tetracycline in N. gonorrhoeae (TRNG) isolates was screened by the agar plate dilution method. Plasmid types were determined for TRNG and PPNG isolates using polymerase chain reaction (PCR). Minimum inhibitory concentrations (MICs) to penicillin and tetracycline were detected by the agar plate dilution.ResultsOf 1378 consecutive N. gonorrhoeae isolates, 429 PPNG and 639 TRNG isolates were identified. The prevalence of PPNG, TRNG, and PPNG/TRNG increased from 18.3 to 47.1 % (χ2 = 31.57, p < 0.001), from 29.4 to 52.1 % (χ2 = 16.28, p < 0.001) and from 10.0 to 26.2 % (χ2 = 10.46, p < 0.001) between 2002 and 2012, respectively. Genotyping of plasmids among PPNGs showed that the majority (93.7 %) of the isolates were the Asian type plasmids, while the African type plasmid emerged in 2008 and rapidly increased to 14.0 % in 2012 (χ2 = 25.03, p < 0.001). For TRNGs, all 639 isolates carried the Dutch type plasmid. MICs of penicillin G and tetracycline persisted at high levels and the MIC90s were 32-fold higher than the resistant cutoff point over 11 years. The prevalence rates of penicillin- and tetracycline-resistant N. gonorrhoeae varied from 90.9 to 91.1 % and from 88.3 to 89.3 % during 2002 to 2012, respectively.ConclusionsResistance to penicillin and tetracycline among N. gonorrhoeae isolates remained at high levels in Guangzhou. The Asian type PPNG continued to spread and Dutch type TRNG was still the dominant strain. The African type PPNG has emerged and is spreading rapidly.

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

Gonorrhoea is one of the most common sexually transmitted infections (STI) in developing countries and is a global health problem. To analyze the trend of antimicrobial susceptibility of Neisseria gonorrhoeae isolates over the years, in a tertiary care hospital of North India. The study population comprised males with urethritis and females with endocervicitis attending STI clinic of our hospital. 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. Data were expressed as percentages. The differences in percentages were tested for statistical significance by using χ2 test and P values were determined. 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). 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.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from symptomatic men attending the Nanjing sexually transmitted diseases clinic (2011-2012): genetic characteristics of isolates with reduced sensitivity to ceftriaxone.

BackgroundEvolving 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 β-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 β-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.ConclusionsN. 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).Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0622-0) contains supplementary material, which is available to authorized users.

P5.103 Increase of African-Type Penicillinase-Producing N. Gonorrhoeae Strains Isolated in Guangzhou, China, 2001–2011

Background The continuing spread of drug-resistant gonococci has posed a challenge for successful treatment worldwide. Guangdong Province in South China has one of the highest resistance rates of gonococci in China and a large number of international migrants. We investigated the in vitro antimicrobial susceptibility and genotypes of N. gonorrhoeae isolated in Guangzhou, the capital city, in 2001–11. Methods MICs to penicillin, ceftriaxone, tetracycline, ciprofloxacin, and spectinomycin were determined by agar plate dilution and susceptibilities were interpreted according to WHO standards. Penicillinase-producing N. gonorrhoeae (PPNG) was determined by paper acidometric testing and high-level tetracycline resistant N. gonorrhoeae (TRNG) by MIC. The isolates with resistant plasmids were genotyped by PCR. Results Of 1250 consecutive gonococci isolated during 2001–11, no ceftriaxone and spectinomycin resistant strains were found, but the prevalence of less susceptible strains to ceftriaxone rose from 17% to 46.5%. The MIC 90 for ceftriaxone showed intermediate sensitivity (0.06–0.125µg/mL) and spectinomycin near the resistant level (16–32µg/mL). The resistance to penicillin, tetracycline and ciprofloxacin were from 85%, 85% and 78% in 2001 to 81.9%, 100% and 98.4% in 2011, respectively. Of 349 (27.9%) PPNG and 539 (43.1%) TRNG detected. 232 (18.6%) strains were both PPNG and TRNG. PPNG increased from 17.0% to 32.3% and TRNG from 26.0% to 41.7% during 2001–10. Genotyping TEM-1 gene showed 94.8% PPNGs carrying the Asia-type β-lactamase plasmids. The Africa-type PPNG (1, 1.3%) emerged in 2008 and has increased to 8(6.2%) in 2011. Genotyping of tetM gene showed all TRNGs were Dutch variants. Conclusion Gonorrhea resistance continues to be a major public health problem in Guangzhou. The emergence and increase of African-type PPNG may be related to the large African diasporas in Guangzhou, migration of Chinese to Africa, or other migration patterns. More research is needed to determine what practises, systems and behaviours contribute to escalating resistance patterns.

P1.016 Molecular Analysis of Antimicrobial Resistant Neisseria Gonorrhoea Isolates from Delhi, India: A Functional Genomics Approach

BackgroundIn India, knowledge regarding N. gonorrhoeae antimicrobial resistance profiling is limited, and data concerning genetic characteristics of N. gonorrhoeae is also lacking. Herein, we investigated the genetic resistance determinants for...

O15.6 Molecular Surveillance of Neisseria Gonorrhoeae Penicillin Resistance: Informing Empiric Prescribing Policy in Western Australia

Against the worldwide trend, there remain populations in the remote regions of Western Australia (WA) where the efficacy rates for penicillin may be above the World Health Organisation (WHO) 95%...

P5.101 Rising Trend of Antimicrobial Resistance Among Neisseria Gonorrhoeae Isolates in a Central Delhi Tertiary Care Hospital

BackgroundGonorrhoea continues to be a common sexually transmitted disease (STD) in developing countries. Over the last decade, N.gonorrhoeae has developed resistance against antimicrobial agents such as penicillin, tetracycline and quinolones...

Antimicrobial Resistance ofNeisseria gonorrhoeaeIsolated in Korea

Neisseria gonorrhoeae is the causative agent of gonorrhea, one of the most important sexually transmitted diseases. The incidence of gonorrhea is still prevalent and about 50,000 new cases have been reported annually during the late 2000s in Korea. The antimicrobial resistance of N. gonorrhoeae is very prevalent and most isolates are multi-drug resistant to penicillin G, tetracycline, and fluoroquinolones. The incidence of penicillinase-producing N. gonorrhoeae (PPNG) decreased significantly, but high-level tetracycline-resistant N. gonorrhoeae (TRNG) increased recently. The minimum inhibitory concentrations (MICs) of ceftriaxone were within the susceptible range for all isolates, but MIC creep has been apparent and one cefixime-nonsusceptible isolate (0.5 ㎍/㎖) was found. Spectinomycin-resistant isolates remain rare, but caution should be required when dealing with gonococcal pharyngitis.

P1-S1.41 Emergence of an African antimicrobial resistance genotype in Neisseria gonorrhoeae strains isolated in Guangzhou, China, 2001–2009

BackgroundThe continuing spread of drug-resistant gonococci has posed a challenge for successful treatment worldwide. Recently third-generation cephalosporins-resistant strains were isolated in Japan. Guangdong Province in South China has one of...

Nationwide external quality assessment for drug susceptibility testing of Neisseria gonorrhoeae from 2007 to 2009

Objective To make a nationwide external quality assessment for drug sensitivity testing of Neisseria gonorrhoeae, analyze the problems in and factors associated with the drug sensitivity testing, and to enhance the quality of drug sensitivity testing of N. gonorrhoeae at different monitoring sites. Methods Samples were uniformly delivered to monitoring sites by express mail service. Test results were analyzed in the National Center for STD Control, and the evaluation results were fed back to these monitoring sites. Results A total of 105 quality control samples were delivered from 2007 to 2009, with a response rate of 88.57% (93/105). Thirteen monitoring sites were enrolled in the external quality assessment, including 9 laboratories in 2007, 9 in 2008 and 13 in 2009. The total percentage amounted to 77.42% (24/31) for qualified laboratories during the 3 years, including 6 laboratories in 2007, 7 in 2008 and 11 in 2009. The coincidence rate increased for the detection of penicillinase-producing N. gonorrhoeae (PPNG), N. gonorrhoeae with chromosome-mediated ciprofloxacin resistance, and N. gonorrhoeae with chromosome-mediated spectinomycin resistance, and declined for the detection of N. gonorrhoeae with plasmid-mediated high level tetracycline-resistance (TRNG) and N. gonorrhoeae with chromosome-mediated ceftriaxone resistance. Conclusions The 3-year external quality assessment reveals an improvement in the overall quality of drug sensitivity testing of N. gonorrhoeae at national monitoring sites; the accuracy is improved markedly for the detection of PPNG, N. gonorrhoeae with resistance to spectinomycin and ciprofloxacin, but is needed to increase for the detection of ceftriaxone-resis- tant N. gonorrhoeae and TRNG. Key words: Neisseria gonorrhoeae; Microbial sensitivity tests; Quality assurance

Plasmid-Mediated Penicillin and Tetracycline Resistance Among Neisseria gonorrhoeae Isolates in South Africa: Prevalence, Detection and Typing Using a Novel Molecular Assay

To detect and type plasmids responsible for penicillin and tetracycline resistance in Neisseria gonorrhoeae isolates using a novel duplex polymerase chain reaction (PCR) assay. A duplex PCR assay, to detect and type penicillinase-producing N. gonorrhoeae (PPNG), and plasmid-mediated tetracycline resistant N. gonorrhoeae (TRNG), was developed on the basis of published single assays. Gonococcal Isolate Surveillance Project control strains were used in assay development and then 209 consecutive N. gonorrhoeae isolates, collected from men with urethral discharge in 2008, were tested. Controls included Asia, Africa, and Toronto β-lactamase plasmids, as well as American and Dutch TRNG plasmids. PCR amplicons were detected using an Agilent 2100 Bioanalyzer. Minimum inhibitory concentrations (MIC) were determined with E tests. Penicillinase production was detected using Nitrocefin solution. Among 209 gonococcal isolates, 54 (25.8%) PPNG and 154 (73.3%) TRNG were detected. The MIC50 and MIC90 values were determined for penicillin (0.19 and 32 mg/L) and tetracycline (6 and 16 mg/L). The assay detected the Africa-type (35.2%), the Toronto-type (44.4%), and a new type (20.3%) of β-lactamase plasmid. The American-type TRNG plasmid was 3-fold more frequent as compared with the Dutch-type. Although there was no overall association between the detection of PPNG and TRNG plasmids, only American type TRNG contained β-lactamase-encoding plasmids (P < 0.0001). The prevalence of plasmid-mediated resistance to tetracycline, and to a lesser extent penicillin, is high and neither drug is likely to have any future role in the treatment of gonorrhoea in South Africa. A novel β-lactamase plasmid was detected during the study and requires further characterization.

Testing of Nebulizers for Delivering Magnesium Sulfate to Pediatric Asthma Patients in the Emergency Department

As the use of intravenous magnesium sulfate (MgSO(4)) for the treatment of refractory asthma is becoming more common, the incidence of MgSO(4)-related systemic hypotension is also rising. One option is to deliver MgSO(4) via aerosol, but compared to most inhaled medications, which are active in the microgram dose range, the MgSO(4) dose requirement is in the milligram range. This, along with inefficient aerosol delivery systems, may be the reason that some studies have found lack of efficacy with aerosol MgSO(4). In preparation for a multicenter study of inhaled MgSO(4) in asthmatic children 2-17 years old, we conducted an in vitro study to choose the best MgSO(4) nebulizer system that would be effective over the entire age range. We tested the Pari LC Star jet nebulizer, Omron MicroAir vibrating-mesh nebulizer, and the Aeroneb Go vibrating-mesh nebulizer with the Idehaler valve-less holding chamber. Aerosol delivery was via face mask. The Pari LC Star had an appropriate particle size distribution but a very slow aerosol output rate. The Omron MicroAir had an even slower output rate and a larger particle size distribution, which would be inappropriate for smaller children. In vitro lung deposition with the Aeroneb Go with Idehaler was 16.0 ± 0.4 mg/min in older children and approximately a fifth of that in toddlers. The Aeroneb Go with Idehaler was chosen for the multicenter clinical study.

One-step PCR for the identification of multiple antimicrobial resistance in Neisseria gonorrhoeae

One-step multiplex PCR was developed for the identification of gonococci and antimicrobial-resistant profiles. From forty Neisseria gonorrhoeae isolates, the penicillinase-producing N. gonorrhoeae (PPNG), the high-level tetracycline-resistant N. gonorrhoeae (TRNG), and the ciprofloxacin-resistant N. gonorrhoeae (CRNG) were successfully classified. Our method provides expediency and benefit to epidemiology and antimicrobial-resistance mobility with 100% sensitivity and specificity for gonococcal-detection. The detection limit was 500 CFU/reaction.