Microbial resistance to nanotechnologies:An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery.Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms.With tunable physicochemical properties,nanomaterials can be designed to be bactericidal,antifouling,immunomodulating,and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy.Despite its substantial advancement,an important,but under-explored area,is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies.This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Evaluation of rational use of antimicrobial agents in a Brazilian intensive care unit

The present study sought to assess the rational use of antimicrobial agents in a Brazilian intensive care unit (ICU) and its association with antimicrobial resistance in elderly patients admitted to the unit. Results: Choice of empiric and sensitivity-guided therapy was inadequate in > 80% and 59% of cases respectively. Inadequate antimicrobial therapy, whether empiric or sensitivity-guided, was positively correlated with bacterial resistance (r = 0.316;p = 0.001). Sensitivity testing revealed a 46.5% resistance rate to eight out of the ten most commonly used antibiotics. Multiple drug-resistant organisms were found in 40.8% of patients. A significant increase was observed in the number of multidrug-resistant samples between 2006/2007 and 2008 (r = 0.41, p = 0.006), (r = 0.598, p = 0.001), (r = 0.688, p = 0.00). Conclusion: We found a high rate of antibiotic misuse in the study sample. Inadequate therapy was correlated with resistance to antimicrobial agents.

Detection of Helicobacter pylori resistance to clarithromycin and fluoroquinolones in Brazil:A national survey

AIM To evaluate bacterial resistance to clarithromycin and fluoroquinolones in Brazil using molecular methods.METHODS The primary antibiotic resistance rates of Helicobacter pylori(H. pylori) were determined from November 2012 to March 2015 in the Southern,South-Eastern,Northern,North-Eastern,and Central-Western regions of Brazil. Four hundred ninety H. pylori patients [66% female,mean age 43 years(range: 18-79)] who had never been previously treated for this infection were enrolled. All patients underwent gastroscopy with antrum and corpus biopsies and molecular testing using Geno Type Helico DR(Hain Life Science,Germany). This test was performed to detect the presence of H. pylori and to identify point mutations in the genes responsible for clarithromycin and fluoroquinolone resistance. The molecular procedure was divided into three steps: DNA extraction from the biopsies,multiplex amplification,and reverse hybridization. RESULTS Clarithromycin resistance was found in 83(16.9%) patients,and fluoroquinolone resistance was found in 66(13.5%) patients. There was no statistical difference in resistance to either clarithromycin or fluoroquinolones(P = 0.55 and P = 0.06,respectively) among the different regions of Brazil. Dual resistance to clarithromycin and fluoroquinolones was found in 4.3%(21/490) of patients. The A2147 G mutation was present in 90.4%(75/83),A2146 G in 16.9%(14/83) and A2146 C in 3.6%(3/83) of clarithromycin-resistant patients. In 10.8%(9/83) of clarithromycin-resistant samples,more than 01 mutation in the 23 S r RNA gene was noticed. In fluoroquinolone-resistant samples,37.9%(25/66) showed mutations not specified by the Geno Type Helico DR test. D91 N mutation was observed in 34.8%(23/66),D91 G in 18.1%(12/66),N87 K in 16.6%(11/66) and D91 Y in 13.6%(9/66) of cases. Among fluoroquinolone-resistant samples,37.9%(25/66) showed mutations not specified by the Geno Type Helico DR test. CONCLUSION The H. pylori clarithromycin resistance rate in Brazil is at the borderline(15%-20%) for applying the standard triple therapy. The fluoroquinolone resistance rate(13.5%) is equally concerning.

In vitro antimicrobial and synergistic effect of essential oil from the red macroalgae Centroceras clavulatum (C. Agardh) Montagne with conventional antibiotics

Objective:To study the chemical profile,antimicrobial properties,and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum(C.Agardh)Montagne,collected in Morocco.Methods:The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry.The oil was evaluated for antibacterial(Pseudomonas aeruginosa,Escherichia coli,Bacillus subtilis,Micrococcus luteus,Staphylococcus aureus,and Klebsiella pneumoniae),and antifungal activity(Candida albicans,Candida glabrata,Candida krusei,and Candida parapsilosis),by the disc diffusion method.The minimum inhibitory and minimum microbicidal concentrations of the oil were determined,as well as the synergistic effects of its application combined with the antibiotics ciprofloxacin and fluconazole,by the checkerboard method.Results:Thirty molecules were identified in the essential oil,comprising 96.27%of the total oil composition.Monoterpenes such as carvacrol(36.06%)were the most abundant compounds,followed by caryophyllene(14.67%),endo-borneol(9.04%),pyroterebic acid(3.23%)and caryophyllene oxide(3.13%).The oil exhibited a moderate antimicrobial activity with inhibition zone diameters ranging from 9.0 to 15.0 mm.The minimum inhibitory concentration values varied between 0.9 and 14.7 mg/mL,and Bacillus subtilis and Escherichia coli were the more sensitive bacteria with 0.9 and 1.9 mg/mL,respectively.The minimum microbicidal concentration values ranged from 0.4 to 14.7 mg/mL.A significant synergic action was observed when the oil was applied in combination with ciprofloxacin and fluconazole,with fractional inhibitory concentration index values ranging from 0.31 to 0.50.Synergy was found in 80%of the combinations and a 2 to 16-fold reduction of antibiotics MIC was observed.Conclusions:Our findings suggest that the essential oil of Centroceras clavulatum should be further appraised for its potential use in the management of multi-drug resistant microorganisms,with the purpose to restore the activity of standard antimicrobial drugs.

A Five-year Surveillance of Carbapenemase-producing Klebsiella pneumoniae in a Pediatric Hospital in China Reveals Increased Predominance of NDM-1

Objective To characterize carbapenem （CPM）-non-susceptible Klebsiella pneumoniae （K. pneumoniae） and carbape-nemase produced by these strains isolated from Beijing Children＇s Hospital based on a five-year surveillance. Methods The Minimal Inhibition Concentration values for 15 antibiotics were assessed using the Phonixl00 compact system. PCR amplification and DNA sequencing were used to detect genes encoding carbapenemases. WHONET 5.6 was finally used for resistance analysis. Results In total, 179 strains of CPM-non-susceptible K. pneumoniae were isolated from January, 2010 to December, 2014. The rates of non-susceptible to imipenem and meropenem were 95.0% and 95.6%, respectively. In the 179 strains, 95 （53.1%） strains carried the blalMP gene, and IMP-4 and IMP-8 were detected in 92 （96.8%） and 3 （3.2%） IMP-producing isolates, respectively. 65 （36.3%） strains carried the blaNDM_1 gene. 6 （3.4%） strains carried the blaKpc gene, and KPC-2 were detected in 6 KPC-producing isolates. In addition, New Delhi-Metallo-1 （NDM-1） producing isolates increased from 7.1% to 63.0% in five years and IMP-4 producing isolates decreased from 75.0% to 28.3%. Conclusion High frequencies of multiple resistances to antibiotics were observed in the CPM-non-susceptible K. pneumoniae strains isolated from Beijing Children＇s Hospital. The production of IMP-4 and NDM-1 metallo-13-1actamases appears to be an important mechanism for CPM-non- susceptible in K. pneumoniae.

Healthcare Professionals’ Adherence to Contact Precautions at a Maternal and Child Teaching Hospital

Background: Healthcare-associated infections affect hundreds of millions of patients worldwide. Children have greater susceptibility to healthcare-associated infections due to the immaturity of their immune system. Contact precautions aim to promote safety, protection and prevention of contamination. Thus, the objective of this study was to verify adherence to contact precaution measures, as well as compliance to the use of personal protective equipment. Methods: This cross-sectional observational study was carried out from July to October 2019 using a checklist to evaluate health professionals’ adherence to hand hygiene procedures and the use of gloves and surgical gowns when assisting children on contact precautions. Results: A total of 941 observations were carried out in a total of 300.532 hours. Hand hygiene was performed before and after contact with the patient in 58.84% and 75.09% of the cases, respectively and a surgical gown was used in 86.40% of the cases. The use of gloves was the variable most adhered to by professionals (87.57%). Intensive care unit professionals were the care workers who most complied with the regulation regarding hand hygiene after contact with the patient (p = 0.009) and the use of the surgical gown (p < 0.001). The correct hand hygiene technique was the recommendation with least adherence. Non-compliance to the hand hygiene technique was statistically significant among intensive care unit professionals (p = 0.002). Conclusions: Adherence to hand hygiene before contact with the patient and compliance with the hand hygiene technique were neglected by most professionals. However, there was good adherence to the use of surgical gloves and gowns, as well as high compliance to the techniques of removing these items. .

Combatting Antibiotic Resistance:Regulatory Exclusivities for New Antibiotic Development in the United States and Europe

Antimicrobial resistance is a global concern that has led to millions of deaths worldwide.Genetic changes occur naturally in pathogens such as viruses,bacteria,parasites,and fungi.To overcome these concerns,there is a need to develop a new generation of antimicrobials.In an effort to encourage innovation,both the United States(US)and the European Union have introduced exclusivity programs.The US offered 5 years of additional nonpatent exclusivity for Qualified Infectious Disease Products under the Generating Antibiotic Incentives Now Act.In parallel,the European Commission offers a patent extension of 12 months across Europe(EU)countries or the option to sell the vouchers to other pharmaceutical companies through transferable exclusivity extension vouchers.This review focuses on the most important innovative strategies of antibiotic development the drug approvals,their mode of action,spectra of activity,and targeting of microorganisms,in past 5 years were mentioned,and discusses how to overcome the challenges of drug approval under antibiotic exclusivity in the US and EU,which will benefit the companies to develop novel drugs in several nations.

Resistance mechanisms and reprogramming of microorganisms for efficient biorefinery under multiple environmental stresses

In the fermentation process of biorefinery,industrial strains are normally subjected to adverse environmental stresses,which leads to their slow growth,yield decline,a substantial increase in energy consumption,and other negative consequences,which ultimately seriously hamper the development of biorefinery.How to minimize the impact of stress on microorganisms is of great significance.This review not only reveals the damaging effects of different environmental stresses on microbial strains but also introduces commonly used strategies to improve microbial tolerance,including adaptive evolution,reprogramming of the industrial host based on genetic circuits,global transcription machinery engineering(gTME)and bioprocess integration.Furthermore,by integrating the advantages of these strategies and reducing the cost of system operation,the tolerance of industrial strains,combined with production efficiency and process stability,will be greatly improved,and the development prospects of biorefinery will be more widespread.

如何避免抗生素在耳鼻咽喉头颈外科中的过度和不足使用

由于抗生素的不规范使用而导致耐药菌的不断衍生,多药耐药和广泛耐药菌株出现,使药物在人体内的药效不断下降,新出现的感染包括耐药菌感染正成为人类面临的新挑战。目前我们所面临的窘境是细菌耐药使抗生素失去作用,但细菌性感染仍然在肆虐,对人类健康构成极大的威胁。