scholarly journals New treatment options for Neisseria gonorrhoeae in the era of emerging antimicrobial resistance

Sexual Health ◽  
2019 ◽  
Vol 16 (5) ◽  
pp. 449 ◽  
Author(s):  
David A. Lewis

Neisseria gonorrhoeae, the causative agent of gonorrhoea, has rapidly evolved from an exquisitely susceptible pathogen into a ‘superbug’ with the capacity to exhibit an extensively drug resistant (XDR) phenotype. The threat of untreatable gonorrhoea now looms on the horizon while the arsenal of effective antimicrobial agents diminishes with time. Ceftriaxone remains the mainstay of first-line therapy as a single agent or as the backbone of a dual therapy regimen. The implementation of new assays to facilitate ‘precision’ treatment, based on the prediction of N. gonorrhoeae susceptibility to old anti-gonococcal drugs, may enable sparing use of ceftriaxone in those countries that can afford this technology. A few existing drugs, such as ertapenem, can be repositioned to help manage multi-drug resistant and XDR gonorrhoea. Recent clinical trials involving solithromycin and delafloxacin have generated disappointing results in that both agents failed to show non-inferiority to conventional ceftriaxone-based regimens. At present, zoliflodacin and gepotidacin appear to be the most promising antimicrobial agents in clinical development. Both drugs performed well in eradicating urogenital gonorrhoea in recent Phase 2 trials; however, treatment failures were reported at the oropharyngeal site, which is an important site of infection in men who have sex with men and sex workers. Given this observation, it is unlikely that either of these new agents could be promoted for monotherapy of gonorrhoea. The pre-clinical pipeline remains relatively empty of agents likely to progress to clinical development for gonorrhoea treatment and increased investment into gonorrhoea-specific drug discovery is recommended.

2021 ◽  
Vol 70 (4) ◽  
Author(s):  
Balaram Khamari ◽  
Prakash Kumar ◽  
Bulagonda Eswarappa Pradeep

Introduction. Nitrofurantoin is one of the preferred antibiotics in the treatment of uropathogenic multidrug-resistant (MDR) infections. However, resistance to nitrofurantoin in extensively drug-resistant (XDR) bacteria has severely limited the treatment options. Gap statement. Information related to co-resistance or collateral sensitivity (CS) with reference to nitrofurantoin resistant bacteria is limited. Aim. To study the potential of nitrofurantoin resistance as an indicator of the XDR phenotype in Enterobacteriaceae . Methods. One hundred (45 nitrofurantoin-resistant, 21 intermediately resistant and 34 nitrofurantoin-susceptible) Enterobacteriaceae were analysed in this study. Antibiotic susceptibility testing (AST) against nitrofurantoin and 17 other antimicrobial agents across eight different classes was performed by using the Vitek 2.0 system. The isolates were screened for the prevalence of acquired antimicrobial resistance (AMR) and efflux pump genes by PCR. Results. In total, 51 % of nitrofurantoin-resistant and 28 % of intermediately nitrofurantoin resistant isolates exhibited XDR characteristics, while only 3 % of nitrofurantoin-sensitive isolates were XDR (P=0.0001). Significant co-resistance was observed between nitrofurantoin and other tested antibiotics (β-lactam, cephalosporin, carbapenem, aminoglycoside and tetracycline). Further, the prevalence of AMR and efflux pump genes was higher in the nitrofurantoin-resistant strains compared to the susceptible isolates. A strong association was observed between nitrofurantoin resistance and the presence of bla PER-1, bla NDM-1, bla OXA-48, ant(2) and oqxA-oqxB genes. Tigecycline (84 %) and colistin (95 %) were the only antibiotics to which the majority of the isolates were susceptible. Conclusion. Nitrofurantoin resistance could be an indicator of the XDR phenotype among Enterobacteriaceae , harbouring multiple AMR and efflux pump genes. Tigecycline and colistin are the only antibiotics that could be used in the treatment of such XDR infections. A deeper understanding of the co-resistance mechanisms in XDR pathogens and prescription of AST-based appropriate combination therapy may help mitigate this problem.


2020 ◽  
Vol 55 (10) ◽  
pp. 944-957
Author(s):  
Changqing Xie ◽  
Nicole A. McGrath ◽  
Cecilia Monge Bonilla ◽  
Jianyang Fu

Abstract Advanced biliary tract cancers (BTC) include a diverse collection of rare and heterogenous tumors with poor prognosis. The combination of gemcitabine and cisplatin is the established first-line therapy for advanced BTC. There are no accepted standard treatments in the second line setting, though there are several ongoing clinical trials that implement chemotherapy as a therapeutic strategy. The understanding of the molecular landscape of BTC has offered hope of targeted therapies to the identified actionable genomic aberrations, such as FGFR2 gene fusions, mutations of IDH1/2, HER2, BRAC1/2 and BRAF. Pembigatinib has become the first approved targeted therapy for BTC with FGFR2 fusion or other rearrangements. Recent immunotherapy has opened new therapy avenues in BTC with pembrolizumab approved for either microsatellite instability high (MSI-H) or DNA mismatch repair deficient (dMMR) advanced solid tumors, including BTC. The combination of immunotherapy with other modalities is currently being evaluated in different clinical trials, since single agent immunotherapy appears to provide modest benefits in advanced BTC. In this review, we summarize the current status of treatment options, including systemic chemotherapy, targeted therapy, immunotherapy, and various combinations in advanced BTC.


2015 ◽  
Vol 11 (2) ◽  
pp. 109
Author(s):  
Paul G Richardson ◽  
Antonio Palumbo ◽  
Stephen A Schey ◽  
Meletios A Dimopoulos ◽  
Thierry Facon ◽  
...  

Pomalidomide is a distinct immunomodulatory agent with significant activity in relapsed/refractory multiple myeloma (RRMM). The optimal treatment schedule in patients with RRMM who have received multiple lines of treatment, including bortezomib and lenalidomide, is 4 mg/day on days 1–21 of a 28-day cycle in combination with weekly low-dose dexamethasone. Improved responses and outcomes relative to traditional therapies continue to be confirmed in recently completed and ongoing trials. Pomalidomide exhibits direct tumoricidal, immunomodulatory, anti-angiogenic and anti-inflammatory activities, which facilitate combination therapy with agents with complementary mechanisms of action, resulting in greater anti-myeloma effects than single-agent therapy or previous combination therapies. For example, in combination with proteasome inhibitors and traditional chemotherapeutic agents in doublet or triplet regimens, pomalidomide provides high rates of durable response, and represents an important new treatment option for patients with RRMM requiring effective new therapies. Additionally, pomalidomide maintains its efficacy and tolerability profile in difficult-to-treat patients, including the elderly, patients with poor cytogenetics and those with renal impairment. This review summarises the clinical development of pomalidomide and discusses this effective agent for the treatment of patients with RRMM in the context of current myeloma treatment options, as well as potential future directions to further improve patient outcomes.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Atul P. Kulkarni ◽  
Vasant C. Nagvekar ◽  
Balaji Veeraraghavan ◽  
Anup R. Warrier ◽  
Deepak TS ◽  
...  

The emerging antimicrobial resistance leading to gram-positive infections (GPIs) is one of the major public health threats worldwide. GPIs caused by multidrug resistant bacteria can result in increased morbidity and mortality rates along with escalated treatment cost and hospitalisation stay. In India, GPIs, particularly methicillin-resistant Staphylococcus aureus (MRSA) prevalence among invasive S. aureus isolates, have been reported to increase exponentially from 29% in 2009 to 47% in 2014. Apart from MRSA, rising prevalence of vancomycin-resistant enterococci (VRE), which ranges from 1 to 9% in India, has raised concerns. Moreover, the overall mortality rate among patients with multidrug resistant GPIs in India is reported to be 10.8% and in ICU settings, the mortality rate is as high as 16%. Another challenge is the spectrum of adverse effects related to the safety and tolerability profile of the currently available drugs used against GPIs which further makes the management and treatment of these multidrug resistant organisms a complex task. Judicious prescription of antimicrobial agents, implementation of antibiotic stewardship programmes, and antibiotic policies in hospitals are essential to reduce the problem of drug-resistant infections in India. The most important step is development of newer antimicrobial agents with novel mechanisms of action and favourable pharmacokinetic profile. This review provides a synopsis about the current burden, treatment options, and the challenges faced by the clinicians in the management of GPIs such as MRSA, Quinolone-resistant Staphylococcus, VRE, and drug-resistant pneumococcus in India.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S798-S798
Author(s):  
Jose Alexander ◽  
Amy Carr ◽  
Sarah B Minor ◽  
Daniel Navas

Abstract Background Antimicrobial resistance in Stenotrophomonas maltophilia is one of the most complex among Gram-negatives. Presence of regulating non-specific antimicrobial class efflux pumps and chromosomal encoded L1 metallo-betalactamase (Ambler Class B) and L2 betalactamase (Ambler Class A) are responsible for few clinically active antimicrobials and pan-drug resistant strains. Methods A 38 year old male with a history of IV drug use, chronic hepatitis C, and recent MSSA endocarditis was admitted with sepsis. Workup revealed tricuspid valve endocarditis with pulmonary septic emboli due to S. maltophilia. Initial antibiotics were levofloxacin (LVX), metronidazole, and piperacillin-tazobactam (TZP) followed by LVX and minocycline (MIN). He had valve replacement on day 6. Repeat blood cultures and valve tissue culture revealed pan-resistant S. maltophilia (resistant: ceftazidime (CAZ), LVX, MIN, TMP/SMX, chloramphenicol; intermediate: MIN; eravacycline MIC 8 μg/mL; tigecycline MIC 16 μg/mL). Microbiology Department was consulted for additional antimicrobial options. In vitro testing for aztreonam (ATM) with ceftazidime/avibactam (CZA) was recommended. Results Synergy testing between ATM and CZA was performed by positioning ATM strip over the area where CZA had been previously been placed and removed after 10 minutes of incubation. The interception of the growth with the ATM strip was read. In presence of avibactam, ATM MIC was 4 μg/mL, 6 two-fold dilutions lower than ATM without CZA. MIC for ATM (256 μg/mL), CAZ (256 μg/mL) and CZA (32 μg/mL) were tested individually. ATM with CZA was recommended as a salvage treatment based on in vitro result. Patient completed 6 weeks of ATM with CZA along with MIN. He achieved microbiologic clearance and clinical recovery from infection. At the end of treatment, he experienced episodes of refractory ascites. With complex comorbidities, patient was not a transplant candidate and transitioned to hospice two weeks later. Conclusion Although the surgical excision was key, treatment with ATM and CZA provided effective antimicrobial treatment in the setting of persistent positive blood culture. ATM with CZA should be considered for cases of pan-drug resistant S. maltophilia with limited treatment options. Disclosures All Authors: No reported disclosures


2020 ◽  
Vol 27 (9) ◽  
pp. 1387-1404 ◽  
Author(s):  
Karishma Biswas ◽  
Humaira Ilyas ◽  
Aritreyee Datta ◽  
Anirban Bhunia

Antimicrobial Peptides (AMPs), within their realm incorporate a diverse group of structurally and functionally varied peptides, playing crucial roles in innate immunity. Over the last few decades, the field of AMP has seen a huge upsurge, mainly owing to the generation of the so-called drug resistant ‘superbugs’ as well as limitations associated with the existing antimicrobial agents. Due to their resilient biological properties, AMPs can very well form the sustainable alternative for nextgeneration therapeutic agents. Certain drawbacks associated with existing AMPs are, however, issues of major concern, circumventing which are imperative. These limitations mainly include proteolytic cleavage and hence poor stability inside the biological systems, reduced activity due to inadequate interaction with the microbial membrane, and ineffectiveness because of inappropriate delivery among others. In this context, the application of naturally occurring AMPs as an efficient prototype for generating various synthetic and designed counterparts has evolved as a new avenue in peptide-based therapy. Such designing approaches help to overcome the drawbacks of the parent AMPs while retaining the inherent activity. In this review, we summarize some of the basic NMR structure based approaches and techniques which aid in improving the activity of AMPs, using the example of a 16-residue dengue virus fusion protein derived peptide, VG16KRKP. Using first principle based designing technique and high resolution NMR-based structure characterization we validate different types of modifications of VG16KRKP, highlighting key motifs, which optimize its activity. The approaches and designing techniques presented can support our peers in their drug development work.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3807
Author(s):  
Pierangela Sepe ◽  
Arianna Ottini ◽  
Chiara Carlotta Pircher ◽  
Andrea Franza ◽  
Melanie Claps ◽  
...  

Non-clear cell renal cell carcinomas (RCC) comprise several rare and poorly described diseases, often characterized by bad prognosis and with no standard treatments available. The gap in their clinical management is linked to the poor molecular characterization in handling the treatment of non clear-cell RCC with untailored therapies. Due to their rarity, non-clear RCC are in fact under-represented in prospective randomized trials. Thus, treatment choices are based on extrapolating results from clear cell RCC trials, retrospective data, or case reports. Over the last two decades, various options have been considered as the mainstay for the treatment of metastatic RCC (mRCC), including angiogenesis inhibitors, vascular endothelial growth factor receptor inhibitors, other tyrosine kinase inhibitors (TKIs), as well as MET inhibitors and mammalian targeting of rapamycin (mTOR) inhibitors. More recently, the therapeutic armamentarium has been enriched with immunotherapy, alone or in combination with targeted agents that have been shown to significantly improve outcomes of mRCC patients, if compared to TKI single-agent. It has been widely proven that non-clear cell RCC is a morphologically and clinically distinct entity from its clear cell counterpart but more knowledge about its biology is certainly needed. Histology-specific collaborative trials are in fact now emerging to investigate different treatments for non-clear cell RCC. This review summarizes pathogenetic mechanisms of non-clear cell RCC, the evolution of treatment paradigms over the last few decades, with a focus on immunotherapy-based trials, and future potential treatment options.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zachary D. Aron ◽  
Atousa Mehrani ◽  
Eric D. Hoffer ◽  
Kristie L. Connolly ◽  
Pooja Srinivas ◽  
...  

AbstractBacterial ribosome rescue pathways that remove ribosomes stalled on mRNAs during translation have been proposed as novel antibiotic targets because they are essential in bacteria and are not conserved in humans. We previously reported the discovery of a family of acylaminooxadiazoles that selectively inhibit trans-translation, the main ribosome rescue pathway in bacteria. Here, we report optimization of the pharmacokinetic and antibiotic properties of the acylaminooxadiazoles, producing MBX-4132, which clears multiple-drug resistant Neisseria gonorrhoeae infection in mice after a single oral dose. Single particle cryogenic-EM studies of non-stop ribosomes show that acylaminooxadiazoles bind to a unique site near the peptidyl-transfer center and significantly alter the conformation of ribosomal protein bL27, suggesting a novel mechanism for specific inhibition of trans-translation by these molecules. These results show that trans-translation is a viable therapeutic target and reveal a new conformation within the bacterial ribosome that may be critical for ribosome rescue pathways.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii282-iii282
Author(s):  
Rafael Moleron ◽  
Sara Stoneham ◽  
Thankamma Ajithkumar ◽  
Justin Cross ◽  
James Nicholson ◽  
...  

Abstract INTRODUCTION Patients with localised CNS-germinoma have excellent survival. More recently, intensive inpatient chemotherapy (carboPEI=carboplatin/etoposide/ifosfamide in Europe) has been effectively employed to reduce radiotherapy fields and/or dose. Current research priorities focus on reducing treatment burden and long-term sequelae. Of note, outpatient-based single-agent carboplatin chemotherapy is associated with excellent outcomes in metastatic testicular seminoma (an identical pathology) [Alifrangis,EJC,2020]. Recently, successful vinblastine monotherapy was reported in localised CNS-germinoma [Murray,Neurooncol-Adv,2020]. METHODS Due to the COVID-19 pandemic, adapted UK guidelines for germ-cell-tumour management were distributed, including potential non-standard treatment options that would reduce hospital visits/admissions. A 30-year-old patient presented with a 32mmx30mmx35mm diameter solid+multi-cystic localised pineal CNS lesion, consistent radiologically with a germ-cell-tumour with prominent teratoma component. Investigation revealed negative AFP/HCG markers and biopsy-proven pure germinoma. After appropriate consent, the patient commenced 12-week induction with weekly vinblastine monotherapy (low-grade-glioma dosing [Lassaletta,JCO,2016]), with wk6&12 MRI re-assessment prior to definitive radiotherapy. RESULTS Vinblastine was well-tolerated. After initial 4mg/m2 test-dosing (wk1), standard 6mg/m2 was delivered for wk2, but resulted in asymptomatic neutropenia (nadir 0.3x10^9/l) and missed dosing at wk3. Subsequent doses were 4mg/m2, with no further neutropenia. As expected, MRI showed moderate 40% tumour volume reduction by wk12. Surgical resection of the residual presumed teratoma component was undertaken prior to radiotherapy. CONCLUSION Patients with CNS-germinoma have excellent outcomes and reduction of treatment-effects remains a priority. The exquisite chemosensitivity of germinoma, excellent results from monotherapy for metastatic testicular disease, and early promise of vinblastine monotherapy lend itself to further exploration for CNS-germinoma.


2021 ◽  
pp. 164-168
Author(s):  
Nikhila S. Khandwala ◽  
Jason M.L. Miller ◽  
Robert A. Hyde ◽  
Christopher D. Conrady ◽  
Rajesh C. Rao ◽  
...  

We report a finding of a pigmented chorioretinal scar with acute retinal necrosis (ARN) caused by herpes simplex virus 2 (HSV-2) infection rather than toxoplasma, creating an initial diagnostic dilemma. A 53-year-old functionally monocular male presented with painless floaters and blurry vision in his seeing eye over a period of 4 days. An exam demonstrated anterior chamber (AC) reaction, vitritis, multifocal patches of whitening, and an occlusive retinal vasculitis. A superior pigmented chorioretinal scar with overlying contracted vitreous was noted in the periphery with no adjacent retinal whitening. The patient was treated for both ARN and toxoplasma chorioretinitis until PCR study of the vitreous and AC returned positive for HSV-2 and negative for toxoplasmosis. Management consisted of a dual therapy regimen of both oral and intravitreal antiviral agents as well as oral corticosteroids. The patient’s clinical course was complicated by rhegmatogenous retinal detachment within 2 weeks after symptom onset, requiring pars plana vitrectomy with silicone oil and intraoperative intraocular incubation with foscarnet. We review emerging evidence for pigmented chorioretinal scars in ARN specifically caused by HSV-2, as well as diagnostic and treatment dilemmas in the management of ARN and ARN detachments.


Sign in / Sign up

Export Citation Format

Share Document