scholarly journals Metal-loaded zeolite remediation of soils contaminated with pandrug-resistant Acinetobacter baumannii

2020 ◽  
Vol 71 (2) ◽  
pp. 146-151
Author(s):  
Jasna Hrenović ◽  
Svjetlana Dekić ◽  
Jelena Dikić ◽  
Snježana Kazazić ◽  
Goran Durn ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Natural Zeolite ◽  
Antimicrobial Agents ◽  
Cost Effective ◽  
Complete Removal ◽  
Terra Rossa ◽  
Natural Soils ◽  
Simple Modification ◽  
Human Waste ◽  
Development Of Resistance

AbstractDue to the development of resistance to antimicrobial agents, bacterium Acinetobacter baumannii is nowadays a leading cause of nosocomial outbreaks. Clinically relevant A. baumannii outside hospital settings including natural soils affected by human waste represents a public-health risk for humans and animals. The aim of this study was to investigate the potential of metal-loaded zeolites to eliminate viable A. baumannii from artificially contaminated natural soils. A. baumannii isolate was subjected to the activity of natural zeolitised tuff (NZ) and Cu-modified (CuNZ) or Ag-modified zeolite (AgNZ) in wet, slightly acidic terra rossa and slightly alkaline red palaeosol. A. baumannii survived in terra rossa and red palaeosol supplemented with 1 wt% of NZ for seven days and four months, respectively. The addition of 1 wt% of CuNZ to terra rossa and red palaeosol shortened the survival of A. baumannii to three and 14 days, respectively. The addition of 0.1 wt% of AgNZ to both soils resulted in complete removal of viable A. baumannii within 1 h of contact, while the total native heterotrophic bacterial counts remained high. Since AgNZ is prepared with a simple modification of cost-effective and environmentally friendly natural zeolite, it is a promising material for the remediation of soils contaminated with pandrug-resistant A. baumannii.

Coumarin-1,2,3-triazole Hybrid Molecules: An Emerging Scaffold for Combating Drug Resistance

2021 ◽  
Vol 21 ◽  
Author(s):  
Harish C. Upadhyay
Keyword(s):  
Drug Resistance ◽  
Antimicrobial Agents ◽  
Plant Secondary Metabolites ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Biologically Active ◽  
Multidrug Therapy ◽  
Diverse Range ◽  
Development Of Resistance ◽  
Hybrid Molecules

: No doubt antibiotics have saved billions of lives, but lack of novel antibiotics, development of resistance mechanisms in almost all clinical isolates of bacteria, and recurrent infections caused by persistent bacteria hamper the successful treatment of infections. Due to widespread emergence of resistance, even the new families of antimicrobial agents have a short life expectancy. Drugs acting on single target often lead to drug resistance and are associated with various side effects. To overcome this problem either multidrug therapy or single drug acting on multiple targets may be used. The later are called ‘hybrid molecules’ which are formed by clubbing two biologically active pharmacophores together with or without an appropriate linker. In this rapidly evolving era, the development of natural product-based hybrid molecules may be a super-alternative to multidrug therapy to combat drug resistance caused by various bacterial and fungal strains. Coumarins (benzopyran-2-one) are one of the earliest reported plant secondary metabolites having clinically proven diverse range of pharmacological properties. On the other hand, 1,2,3-triazole is a common pharmacophore in many drugs responsible for polar interactions improving the solubility and binding affinity to biomolecular targets. In this review we discuss recent advances in Coumarin-1,2,3-triazole hybrids as potential antibacterial agents aiming to provide a useful platform for the exploration of new leads with broader spectrum, more effectiveness, less toxicity with multiple modes of action for the development of cost-effective and safer drugs in the future.

scholarly journals Antibiotic-Resistant Acinetobacter baumannii in Low-Income Countries (2000–2020): Twenty-One Years and Still below the Radar, Is It Not There or Can They Not Afford to Look for It?

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 764
Author(s):  
Soha S. Rizk ◽  
Wafaa H. Elwakil ◽  
Ahmed S. Attia
Keyword(s):  
Acinetobacter Baumannii ◽  
Low Income ◽  
Antimicrobial Agents ◽  
Genetic Resistance ◽  
Infectious Agent ◽  
Carbapenem Resistance ◽  
Healthcare Services ◽  
Low Income Countries ◽  
Surveillance Systems ◽  
Development Of Resistance

Acinetobacter baumannii is an emerging pathogen, and over the last three decades it has proven to be particularly difficult to treat by healthcare services. It is now regarded as a formidable infectious agent with a genetic setup for prompt development of resistance to most of the available antimicrobial agents. Yet, it is noticed that there is a gap in the literature covering this pathogen especially in countries with limited resources. In this review, we provide a comprehensive updated overview of the available data about A. baumannii, the multi-drug resistant (MDR) phenotype spread, carbapenem-resistance, and the associated genetic resistance determinants in low-income countries (LIICs) since the beginning of the 21st century. The coverage included three major databases; PubMed, Scopus, and Web of Science. Only 52 studies were found to be relevant covering only 18 out of the 29 countries included in the LIC group. Studies about two countries, Syria and Ethiopia, contributed ~40% of the studies. Overall, the survey revealed a wide spread of MDR and alarming carbapenem-resistance profiles. Yet, the total number of studies is still very low compared to those reported about countries with larger economies. Accordingly, a discussion about possible reasons and recommendations to address the issue is presented. In conclusion, our analyses indicated that the reported studies of A. baumannii in the LICs is far below the expected numbers based on the prevailing circumstances in these countries. Lack of proper surveillance systems due to inadequate financial resources could be a major contributor to these findings.

Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

2020 ◽  
Vol 21 ◽  
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Marine Organisms ◽  
Antimicrobial Compounds

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.

A Novel Approach for the Treatment of Sialolithiasis that Preserves Salivary Duct Anatomy

2021 ◽  
pp. 000348942110189
Author(s):  
Gani Atilla Şengör ◽  
Ahmet Mert Bilgili
Keyword(s):  
Salivary Gland ◽  
Success Rate ◽  
Cost Effective ◽  
Complete Removal ◽  
Level Of Evidence ◽  
Invasive Approach ◽  
Pneumatic Lithotripsy ◽  
Novel Approach ◽  
Surgical Methods ◽  
Salivary Gland Stones

Objective: The sialendoscopy era in the treatment of salivary gland stones has reduced the use of classical surgical methods. However, the miniature ducts and tools may cause difficulties in removing large sialoliths. Therefore, invasive combined oral surgeries or gland resection may be considered. We searched for the most suitable method in order to stay in line with the minimally invasive approach that preserves the ductus anatomy, and that can reduce the surgical fears of patients. Materials and Methods: The study included 84 cases (23 parotid and 61 submandibular) in whom stones were fragmented by pneumatic lithotripsy and removed between January 2015 and January 2020. The parotid cases comprised 7 females and 16 males, and the submandibular cases comprised 25 females and 36 males. Intraductal lithotripsy was performed using pneumatic lithotripter. This study has fourth level of evidence. Results: Based on total number of cases (n = 84), success rate was 67/84 (79.7%) immediately after sialendoscopy, and overall success rate was 77/84 (91.6%). Based on number of stones treated (n = 111), our immediate success rate was 94/111 (84.6%), and overall success rate was 104/111 (93.7%). The success criteria were complete removal of the stone and fragments in a single sialendoscopy procedure and resolution of symptoms. Conclusions: We successfully treated salivary gland stones, including L3b stones, in our patient cohort with sialendoscopy combined with pneumatic lithotripsy. The lithotripsy method that we have adapted seems to be more useful and cost-effective compared to its alternatives. We were also able to preserve the ductus anatomy and relieve patients’ concerns. Level of Evidence: Level IV

scholarly journals Silver (I) N-Heterocyclic Carbene Complexes: A Winning and Broad Spectrum of Antimicrobial Properties

2021 ◽  
Vol 22 (5) ◽  
pp. 2497
Author(s):  
Filippo Prencipe ◽  
Anna Zanfardino ◽  
Michela Di Napoli ◽  
Filomena Rossi ◽  
Stefano D’Errico ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Resistance Mechanisms ◽  
Heterocyclic Carbenes ◽  
Significant Activity ◽  
Bacterial Strains ◽  
Development Of Resistance ◽  
Starting Point ◽  
Catalytic Chemistry

The evolution of antibacterial resistance has arisen as the main downside in fighting bacterial infections pushing researchers to develop novel, more potent and multimodal alternative drugs.Silver and its complexes have long been used as antimicrobial agents in medicine due to the lack of silver resistance and the effectiveness at low concentration as well as to their low toxicities compared to the most commonly used antibiotics. N-Heterocyclic Carbenes (NHCs) have been extensively employed to coordinate transition metals mainly for catalytic chemistry. However, more recently, NHC ligands have been applied as carrier molecules for metals in anticancer applications. In the present study we selected from literature two NHC-carbene based on acridinescaffoldand detailed nonclassicalpyrazole derived mono NHC-Ag neutral and bis NHC-Ag cationic complexes. Their inhibitor effect on bacterial strains Gram-negative and positivewas evaluated. Imidazolium NHC silver complex containing the acridine chromophore showed effectiveness at extremely low MIC values. Although pyrazole NHC silver complexes are less active than the acridine NHC-silver, they represent the first example of this class of compounds with antimicrobial properties. Moreover all complexesare not toxic and they show not significant activity againstmammalian cells (Hek lines) after 4 and 24 h. Based on our experimental evidence, we are confident that this promising class of complexes could represent a valuable starting point for developing candidates for the treatment of bacterial infections, delivering great effectiveness and avoiding the development of resistance mechanisms.

scholarly journals OMN6 a novel bioengineered peptide for the treatment of multidrug resistant Gram negative bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shira Mandel ◽  
Janna Michaeli ◽  
Noa Nur ◽  
Isabelle Erbetti ◽  
Jonathan Zazoun ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Safety Margin ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Development Of Resistance ◽  
Cecropin A

AbstractNew antimicrobial agents are urgently needed, especially to eliminate multidrug resistant Gram-negative bacteria that stand for most antibiotic-resistant threats. In the following study, we present superior properties of an engineered antimicrobial peptide, OMN6, a 40-amino acid cyclic peptide based on Cecropin A, that presents high efficacy against Gram-negative bacteria with a bactericidal mechanism of action. The target of OMN6 is assumed to be the bacterial membrane in contrast to small molecule-based agents which bind to a specific enzyme or bacterial site. Moreover, OMN6 mechanism of action is effective on Acinetobacter baumannii laboratory strains and clinical isolates, regardless of the bacteria genotype or resistance-phenotype, thus, is by orders-of-magnitude, less likely for mutation-driven development of resistance, recrudescence, or tolerance. OMN6 displays an increase in stability and a significant decrease in proteolytic degradation with full safety margin on erythrocytes and HEK293T cells. Taken together, these results strongly suggest that OMN6 is an efficient, stable, and non-toxic novel antimicrobial agent with the potential to become a therapy for humans.

In-vessel co-composting – a rapid resource recovery option for septage treatment in Indian cities

2018 ◽  
Vol 8 (4) ◽  
pp. 688-697 ◽  
Author(s):  
Anu Rachel Thomas ◽  
Martin Kranert ◽  
Ligy Philip
Keyword(s):  
Assessment Tool ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Cost Effective ◽  
Organic Load ◽  
Human Waste ◽  
Design Load ◽  
Solids Content ◽  
Chennai City ◽  
Indian Cities

Abstract Septage management is a challenging task across India as more than 44% of the population depends on septic tanks for human waste management. Septage collected from Chennai city, India, was found to be rich in nutrients even though the total solids content (<2%) and C/N are low. The current practice of septage disposal in Chennai city is co-treatment in existing sewage treatment plants. The main drawback of this method is that treatment efficiency could deteriorate if the organic load increased much beyond the design load of the treatment plant and would result in poor treated-water quality. In this context, the present study focused on the potential of in-vessel co-composting as a sustainable treatment option. In order to enhance the co-composting process, suitable co-substrates were identified for making the process efficient and cost-effective. The area under the temperature profile during composting was used as an assessment tool for the identification of the proper mix. Addition of mixed organic waste and coir pith waste (bulking agent) to the dewatered septage gave the highest area among the different combinations. Different waste combinations were investigated in order to assess the suitability for field scale application.

scholarly journals Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates from Egyptian Patients

2020 ◽  
Author(s):  
Reem M Hassan ◽  
Sherifa T Salem ◽  
Saly Ismail Mostafa Hassan ◽  
Asmaa Sayed Hegab ◽  
Yasmine S Elkholy
Keyword(s):  
Acinetobacter Baumannii ◽  
Molecular Characterization ◽  
Antimicrobial Agents ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Common Mechanism ◽  
Carbapenem Resistant ◽  
Egyptian Patients ◽  
Global Threat

AbstractAcinetobacter baumannii (A. baumannii) represents a global threat owing to its ability to resist most of the currently available antimicrobial agents. Moreover, emergence of carbapenem resistant A. baumannii (CR-AB) isolates limits the available treatment options. Enzymatic degradation by variety of ß-lactamases, have been identified as the most common mechanism of carbapenem resistance in A. baumannii. The alarming increase in the prevalence of CR-AB necessitates continuous screening and molecular characterization to appreciate the problem. The present study was performed to assess the prevalence and characterize carbapenemases among 206 CR-AB isolated from various clinical specimens collected from different intensive care units at Kasr Al-Aini Hospital.All isolates were confirmed to be A. baumannii by detection of the blaOXA-51-like gene. Molecular screening of 13 common Ambler class bla carbapenemases genes in addition to insertion sequence (IS-1) upstream OXA-23 was performed by using four sets of multiplex PCR, followed by identification using gene sequencing technology. Among the investigated genes, the prevalence of blaOXA-23, and blaOXA-58 were 77.7%, and 1.9%, respectively. The ISAba1 was detected in 10% of the blaOXA-23 positive isolates. The prevalence of metallo-β-lactamases (MBLs) studied; blaNDM-1, blaSPM, blaVIM, blaSIM-1 were 11.7%, 6.3%, 0.5%, and 0.5% respectively. One of class A; bla KPC was detected in 10.7% of the investigated isolates. blaOXA-24/40, blaIMP, blaGES, blaVEB and blaGIM were not detected in any of the studied isolates. Moreover, 18.4% of the isolates have shown to harbor two or more of the screened bla genes. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC.Author summaryCarbapenem-resistant A. baumannii has become a real global health threat. The aim of the present study was to characterize and to assess the prevalence of carbapenemases among 206 CR-AB clinical isolates from Egyptian patients. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC. In this study, ISAba1 was detected upstream 10% of blaOXA-23 positive isolates only which indicates that the spread of resistance among Acinetobacter isolates could be either chromosomal or plamid-mediated.

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