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

Computational prediction of crucial genes involved in gonorrhea infection and neoplastic cell transformation: A multiomics approach

Neisseria gonorrheae, the causative agent of genitourinary infections, has been associated with asymptomatic or recurrent infections and has the potential to form biofilms and induce inflammation and cell transformation. Herein, we aimed to use computational analysis to predict novel associations between chronic inflammation caused by gonorrhea infection and neoplastic transformation. Prioritization and gene enrichment strategies based on virulence and resistance genes utilizing essential genes from the DEG and PANTHER databases, respectively, were performed. Using the STRING database, protein‒protein interaction networks were constructed with 55 nodes of bacterial proteins and 72 nodes of proteins involved in the host immune response. MCODE and cytoHubba were used to identify 12 bacterial hub proteins (murA, murB, murC, murD, murE, purN, purL, thyA, uvrB, kdsB, lpxC, and ftsH) and 19 human hub proteins, of which TNF, STAT3 and AKT1 had high significance. The PPI networks are based on the connectivity degree (K), betweenness centrality (BC), and closeness centrality (CC) values. Hub genes are vital for cell survival and growth, and their significance as potential drug targets is discussed. This computational study provides a comprehensive understanding of inflammation and carcinogenesis pathways that are activated during gonorrhea infection.

Azithromycin resistance and its molecular characteristics in Neisseria gonorrhoeae isolates from a tertiary care centre in North India

Treatment guidelines for management of uncomplicated gonorrhoeae have been recently modified owing to alarming upsurge in azithromycin resistance. This study investigated the prevalence and genetic determinants of gonococcal azithromycin resistance in India. Four (5.7%) of 70 gonococcal isolates were resistant to azithromycin. Of 16 isolates investigated for molecular mechanisms of resistance, 13 (81.3%) and 6 (37.5%) isolates exhibited mutations in coding and promoter regions of mtrR gene, respectively. However, ermA, ermB and ermC genes or mutations in rrl gene were absent in all isolates. Azithromycin resistance is low in India posing no immediate threat to use of dual-therapy for syndromic management.

Systematic review and survey of Neisseria gonorrhoeae ceftriaxone and azithromycin susceptibility data in the Asia Pacific, 2011 to 2016

BACKGROUND

Antimicrobial resistance in Neisseria gonorrhoeae is a global concern, with the ongoing emergence of ceftriaxone and azithromycin resistance threatening current treatment paradigms. To monitor the emergence of antimicrobial resistance in N. gonorrhoeae, the World Health Organization (WHO) Gonococcal Antimicrobial Surveillance Programme (GASP) has operated in the Western Pacific and South East Asian regions since 1992. The true burden of antimicrobial resistance remains unknown. In response, the objective of this study was to survey ceftriaxone and azithromycin susceptibility in N. gonorrhoeae across the western Pacific and south-east Asia, and interlink this data with systematically reviewed reports of ceftriaxone and azithromycin resistance.

METHODS AND FINDINGS

The WHO Collaborating Centre for Sexually Transmitted Infections and Antimicrobial Resistance, Sydney, coordinated annual surveys of gonococcal susceptibilities with participating laboratories, and additionally undertook a systematic review of reports detailing gonococcal ceftriaxone and azithromycin susceptibility data for locations geographically in the Asia Pacific from 2011 to 2016. It was found that surveillance of gonococcal antimicrobial resistance remains limited in the Asia Pacific, with weaker surveillance of azithromycin versus ceftriaxone. Ninety-three published reports were identified (including national reports) which documented susceptibility data for ceftriaxone and azithromycin. GASP survey data was available for 21 countries, territories or areas, and suggested MICs are increasing for ceftriaxone and azithromycin. Between 2011 and 2016, the percentage of locations reporting >5% of gonococcal isolates with MICs to ceftriaxone meeting WHO's definition of decreased susceptibility (MIC ≥ 0.125 mg/L) increased from 14.3% to 35.3% and the percentage of locations reporting >5% of gonococcal isolates with azithromycin resistance (MIC ≥ 1 mg/L) increased from 14.3% to 38.9%. Published reports were available for several countries that did not provide GASP surveillance responses for ceftriaxone (n = 5) and azithromycin (n = 3) respectively. Over the study period, there was a 183% increase in the number of countries providing surveillance data for GASP for both ceftriaxone and azithromycin, and a 30.6% increase in ceftriaxone MIC testing across the Asia Pacific facilitated by this project.

CONCLUSION

This study provides the first comprehensive illustration of increasing MICs to ceftriaxone in the Asia Pacific. The survey and literature review additionally detail increasing resistance to azithromycin. Further surveillance system strengthening is required to monitor these trends in order to address and curb gonococcal AMR in the region.

In Vitro Synergy Testing of Gentamicin, an Old Drug Suggested as Future Treatment Option for Gonorrhoea, in Combination With Six Other Antimicrobials Against Multidrug-Resistant Neisseria gonorrhoeae Strains

BACKGROUND

Emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Neisseria gonorrhoeae is a serious concern and combination therapy has been recommended to delay the onset of treatment failures. Gentamicin, an old and inexpensive antibiotic, is recommended in combination with azithromycin for treatment failures cases with the first-line regimen as per the latest Centers for Disease Control and Prevention sexually transmitted disease treatment guidelines. However, not much literature is available on in vitro and in vivo efficacy of this combination. Therefore, this study was carried out to evaluate the in vitro synergy of gentamicin in combination with azithromycin and 5 other antimicrobials.

METHODS

In vitro synergy of gentamicin in combination with cefixime, ceftriaxone, spectinomycin, azithromycin, moxifloxacin, and ertapenem was determined by Etest for 75 N. gonorrhoeae strains, of which 65 were MDR and one was XDR. Fractional inhibitory concentration index (FICI) of ≤0.5 and >4.0 denoted synergy and antagonism respectively.

RESULTS

Maximum efficacy of gentamicin was observed in combination with ertapenem (geometric mean FICI, 0.56) followed by cefixime (FICI, 0.87). There was no antagonism for both these combinations. However, antagonism was demonstrated in 5.3%, 8%, 8%, and 10.7% strains when gentamicin was paired with spectinomycin (FICI, 1.34), ceftriaxone (FICI, 1.13), azithromycin (FICI, 1.49), and moxifloxacin (FICI, 1.30), respectively.

CONCLUSIONS

The findings suggest that gentamicin significantly enhances the in vitro therapeutic potency of ertapenem and cefixime which will be potentially effective to control the spread of MDR and XDR N. gonorrhoeae. The study warrants more in vitro studies and clinical trials for gentamicin + azithromycin and other 3 combinations because of considerable antagonism.

Alarming resistance of Neisseria gonorrhoeae in a tertiary care hospital of North India

Background

This study attempted to elucidate the spectrum of sexually transmitted infections in a tertiary care centre in North India and to assess the antimicrobial resistance in Neisseria gonorrhoeae.

Materials and Methods

Antimicrobial resistance pattern of N. gonorrhoeae was determined by the standard techniques. Genotypic detection of gyrA, parC and blaTEM genes was also carried out. The results of gyrA gene by polymerase chain reaction were confirmed by DNA sequencing.

Results

N. gonorrhoea was identified in 10 (4.98%) patients, and antimicrobial sensitivity was performed in seven patients. All the seven patients tested were quinolone-resistant N. gonorrhoeae (QRNG), 5/7 were penicillinase-producing N. gonorrhoeae, 1/7 was chromosomally mediated penicillin-resistant N. gonorrhoeae and 3/7 were tetracycline-resistant N. gonorrhoeae. Minimal inhibitory concentration (MIC) by E-test was performed in five strains, and we observed that MIC90 for ciprofloxacin was ≥4 μg/ml, for penicillin was ≥6 μg/ml and for tetracycline was 12 μg/ml, which clearly brackets them as resistant isolates. The presence of TEM gene was confirmed genotypically in six out of seven cases. In all seven cases, gyrA and parC were observed, thus confirming their QRNG status.

Conclusion

Alarming increase in the resistance to commonly used antimicrobials for gonorrhoea in our study, especially of fluoroquinolones, is a clarion call for the urgent need for prudence in prescribing them. Observing the rampant resistance exhibited by N. gonorrhoeae, it is clear that the day is not far when it will acquire a superbug status and become intractable to treatment by the available antibiotics.

In vitro efficacy of 21 dual antimicrobial combinations comprising novel and currently recommended combinations for treatment of drug resistant gonorrhoea in future era

BACKGROUND

Recent WHO guidelines recommend dual therapy with ceftriaxone or cefixime plus azithromycin for gonorrhea. Azithromycin in combination with gentamicin or spectinomycin has been recommended in treatment failure cases. Due to emergence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) Neisseria gonorrhoeae strains, it is important to look for efficacy of these combinations and also of others that might be used in future. Therefore, we aimed to evaluate in vitro synergy of 21 dual combinations including current and alternative WHO recommended treatment regimens and other dual combinations.

METHODS AND FINDINGS

The potential utility of in-vitro interactions of 21 combinations was investigated against 95 N. gonorrhoeae strains including 79 MDR and one XDR strain collected during March 2013 to July 2017 and fractional inhibitory concentration index (FICI) was calculated. These 21 combinations comprised of two WHO currently recommended (cefixime+azithromycin, ceftriaxone+azithromycin); two WHO recommended in treatment failure cases (azithromycin+gentamicin, spectinomycin+azithromycin) and other 17 combinations.

RESULTS

FICI of the four WHO recommended antimicrobial combinations were higher (>1.0) than the five novel combinationbreeds (FICI range 0.603-0.951) in the study i.e. gentamicin+ertapenem, moxifloxacin+ertapenem, spectinomycin+ertapenem, azithromycin+ moxifloxacin, cefixime+gentamicin. No antagonistic effect of the above four WHO recommended combinations except spectinomycin+azithromycin (FICI = 4.25) was observed for the XDR strain. Out of above five novel combinations, four combinations produced high synergistic effects in overall 95 strains and also for the XDR strain with FICI of 0.13 to 0.38. Antagonistic effects varying from 3.2 to 12.6% were observed for 10 out of 21 tested combinations (azithromycin in combination with gentamicin and spectinomycin; ceftriaxone with moxifloxacin, gentamicin, spectinomycin and ertapenem; spectinomycin with moxifloxacin and gentamicin; cefixime and gentamicin combination with moxifloxacin).

CONCLUSION

WHO recommended cefixime+azithromycin, ceftriaxone+azithromycin combinations having no antagonism indicates their continuing clinical utility. Highest antagonism without any synergistic effect for the WHO recommended spectinomycin+azithromycin in treatment failure cases suggests that this combination should be evaluated further both in vitro and in vivo. Highest synergistic or additive effect without any antagonistic effect of the above five novel combinations suggests that these may be recommended for treatment in future.

Antibiotic susceptibility pattern of Neisseria gonorrhoeae strains isolated from five cities in India during 2013-2016

PURPOSE

Emergence of multidrug resistance in Neisseria gonorrhoeae, an STI of public health significance is the biggest challenge to gonorrhoea control. Monitoring for antimicrobial resistance is essential for the early detection of emergent drug resistance patterns.

METHODOLOGY

One hundred and twenty four N. gonorrhoeae strains were isolated between September 2013-August 2016 [82-New Delhi, 3-Pune, 3-Mumbai, 20-Secunderabad and 16-Hyderabad] to determine antimicrobial susceptibility and to compare the CLSI disc diffusion method with Etest for these strains. The results of the two methods were compared by using kappa statistics.

RESULTS

Ninety eight percent [CI: 96.2-100] of isolates were resistant to ciprofloxacin, 52 % [CI: 43.2-60.8] to penicillin, 56 % [CI: 47.2-64.7] to tetracycline and 5 % [CI: 1.2-8.8] to azithromycin. All the strains were susceptible to spectinomycin, ceftriaxone and cefixime except for two strains which showed decreased susceptibility to ceftriaxone and cefixime. Kappa scores for penicillin, azithromycin, ciprofloxacin, ceftriaxone and cefixime showed that the CLSI method had high agreement with Etest while tetracycline had substantial agreement.

CONCLUSION

Our data suggest that the disc diffusion method which is both cost effective and more feasible, can effectively be used routinely for monitoring antibiotic susceptibility in N. gonorrhoeae, in limited resource countries like India. We demonstrate the emergence of decreased susceptibility to ceftriaxone and cefixime and threshold levels of resistance to azithromycin in India. This underscores the importance of maintaining continued surveillance for antibiotic resistance in N. gonorrhoeae and a potential requirement for strategic change in guidelines in the not so distant future.

How Reliable Is Microscopy and Culture for the Diagnosis of Gonorrhea? An 11-Year Experience from INDIA

Positivity of microscopy and culture was greater (P < 0.0001) in men with urethral discharge syndrome (65.8%) than in women with vaginal/cervical discharge (0.5%), indicating that basic diagnostic tests may not be cost-effective for diagnosis of vaginal/cervical discharge syndrome. Microscopy when compared with culture showed sensitivity, specificity, positive predictive value and negative predictive value of 95.4%, 77.6%, 84.6%, and 95.3%, in men, whereas in women, it was 77.8%, 99.9%, 92.1%, and 99.9%, respectively.

Comparing the disk-diffusion and agar dilution tests for Neisseria gonorrhoeae antimicrobial susceptibility testing

BACKGROUND

We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant Neisseria gonorrhoeae (GC) isolates by disk diffusion in comparison to agar dilution, and Etest® (bioMerieux, France), respectively, for three third generation extended spectrum cephalosporins (ESC): ceftriaxone (CRO), cefixime (CFX), and cefpodoxime (CPD).

METHODS

One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical Laboratory Standard Institute (CLSI) and manufacturer's standards for each of the three methods. The measured diameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition, comparisons with the Etest® were made. Categorical results for concordance, based on standard CLSI cutoffs, between the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics. Reproducibility was tested for CFX across a 6-month interval by repeated disk tests.

RESULTS

Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting concordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest®, for CRO, CFX, and CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MIC's were -0.59, -0.67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest® were -0.58, -0.73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%.

CONCLUSIONS

Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative antimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime.

Gentamicin Susceptibility among a Sample of Multidrug-Resistant Neisseria gonorrhoeae Isolates in India

Antimicrobial susceptibility testing of 258 Neisseria gonorrhoeae isolates by Etest determined that 60.1% were multidrug resistant (MDR), while 5% of the strains had decreased susceptibility to currently recommended extended-spectrum cephalosporins (ESCs). Among these, 84.5% of MDR strains and 76.9% of strains that had decreased susceptibility to ESCs were susceptible to gentamicin. No MDR isolate was resistant to gentamicin. These in vitro results suggest that gentamicin might be an effective treatment option for the MDR strains and in dual therapy for gonorrhea. However, further research regarding the clinical treatment outcomes is essential.