Heavy Metals as Catalysts in the Evolution of Antimicrobial Resistance and the Mechanisms Underpinning Co-selection

The menace caused by antibiotic resistance in bacteria is acknowledged on a global scale. Concerns over the same are increasing because of the selection pressure exerted by a huge number of different antimicrobial agents, including heavy metals. Heavy metals are non-metabolizable and recalcitrant to degradation, therefore the bacteria can expel the pollutants out of the system and make it less harmful via different mechanisms. The selection of antibiotic-resistant bacteria may be influenced by heavy metals present in environmental reservoirs. Through co-resistance and cross-resistance processes, the presence of heavy metals in the environment can act as co-selecting agents, hence increasing resistance to both heavy metals and antibiotics. The horizontal gene transfer or mutation assists in the selection of mutant bacteria resistant to the polluted environment. Hence, bioremediation and biodegradation are sustainable methods for the natural clean-up of pollutants. This review sheds light on the occurrence of metal and antibiotic resistance in the environment via the co-resistance and cross-resistance mechanisms underpinning co-selection emphasizing the dearth of studies that specifically examine the method of co-selection in clinical settings. Furthermore, it is advised that future research incorporate both culture- and molecular-based methodologies to further our comprehension of the mechanisms underlying bacterial co- and cross-resistance to antibiotics and heavy metals.

Electroacupuncture plus standard of care for managing refractory functional dyspepsia: protocol of a pragmatic trial with economic evaluation

INTRODUCTION

This trial proposes to compare the effectiveness and cost-effectiveness of electroacupuncture (EA) plus on-demand gastrocaine with waiting list for EA plus on-demand gastrocaine in providing symptom relief and quality-of-life improvement among patients with functional dyspepsia (FD).

METHODS AND ANALYSIS

This is a single-centre, pragmatic, randomised parallel-group, superiority trial comparing the outcomes of (1) EA plus on-demand gastrocaine group and (2) waiting list to EA plus on-demand gastrocaine group. 132 (66/arm) endoscopically confirmed, Helicobacter pylori-negative patients with FD will be recruited. Enrolled patients will respectively be receiving (1) 20 sessions of EA over 10 weeks plus on-demand gastrocaine; or (2) on-demand gastrocaine and being nominated on to a waiting list for EA, which entitles them 20 sessions of EA over 10 weeks after 12 weeks of waiting. The primary outcome will be the between-group difference in proportion of patients achieving adequate relief of symptoms over 12 weeks. The secondary outcomes will include patient-reported change in global symptoms and individual symptoms, Nepean Dyspepsia Index, Nutrient Drink Test, 9-item Patient Health Questionnaire (PHQ9), and 7-item Generalised Anxiety Disorder Scale (GAD7). Adverse events will be assessed formally. Results on direct medical costs and on the EuroQol (EQ-5D) questionnaire will also be used to assess cost-effectiveness. Analysis will follow the intention-to-treat principle using appropriate univariate and multivariate methods. A mixed model analysis taking into account missing data of these outcomes will be performed. Cost-effectiveness analysis will be performed using established approach.

ETHICS AND DISSEMINATION

The study is supported by the Health and Medical Research Fund, Government of the Hong Kong Special Administrative Region of China. It has been approved by the Joint Chinese University of Hong Kong - New Territories East Cluster Clinical Research Ethics Committee. Results will be published in peer-reviewed journals and be disseminated in international conference.

TRIAL REGISTRATION NUMBER

ChiCTR-IPC-15007109; Pre-result.