scholarly journals Comparative in vitro Activities of Different Antibiotics against Clinical Isolates of Gram-negative Bacilli

2019 ◽  
pp. 1-8
Author(s):  
Sachin H. Jain ◽  
Pradnya Joshi
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Therapeutic Option ◽  
Critical Role ◽  
Final Analysis ◽  
Klebsiella Species ◽  
In Vitro Susceptibility ◽  
Gram Negative ◽  
E Coli

Objective: The local anti-microbial susceptibility profile plays a very critical role in guiding clinicians to choose the appropriate empiric therapies. This study was conducted to assess the pathogen characteristics and the in vitro susceptibility of different Gram negative isolates to commonly used antibiotics in our hospital settings. Methods: A total of 110 Gram negative isolates were included in the study.  A retrospective, observational analysis of antibiogram data was performed for four antimicrobial agents including CSE-1034 (ceftriaxone-sulbactam-EDTA), piperacillin-tazobactam (pip-taz), cefoperazone-sulbactam and meropenem.  Results: Of the 200 clinical specimens analysed, Gram negative isolates obtained from 110 samples were included in the final analysis. The most common Gram negative isolates were Klebsiella species (35.5%), E. coli (33.6%) and P. aeruginosa (21.8%). The overall susceptibility was highest to CSE-1034 (100%) followed by meropenem (66.4%), cefoperazone-sulbactam (56.4%) and pip-taz (45.5%). The MIC90 range of CSE-1034 for Enterobacteriaceae was ≤0.5-≤4μg/ml and ≤2μg/ml for susceptible P. aeruginosa isolates. The MIC90 of meropenem for 94.4% of meropenem-susceptible Enterobacteriaceae strains was <0.25μg/ml and 64.3% of P. aeruginosa were having MIC ≤0.25μg/ml. The MIC90 of pip-taz for 82.5% of the pip-taz susceptible Enterobacteriaceae strains was 4μg/ml and 63.6% of P. aeruginosa was ≤8.0μg/ml. The MIC90 of cefoperazone-sulbactam susceptible strains were between ≤8 to ≤16μg/ml and 45.8% isolates of susceptible P. aeruginosa were having MIC between ≤8 to ≤16μg/ml. Conclusions: Overall, this in vitro surveillance study suggests that CSE-1034 can be considered an important therapeutic option for the treatment of various multi drug resistant Gram-negative bacterial infections and avert the threat of resistance to last resort antibiotics including carbapenems.

scholarly journals In vitro Susceptibility Pattern of Major Gram Negative Isolates to Selected Antimicrobial Agents

2019 ◽  
pp. 1-8
Author(s):  
Shalini Gupta ◽  
Pankaj Mandale
Keyword(s):  
Antimicrobial Susceptibility ◽  
Bacterial Infections ◽  
Therapeutic Option ◽  
Polymyxin B ◽  
Susceptibility Pattern ◽  
In Vitro Susceptibility ◽  
Gram Negative ◽  
E Coli ◽  
Susceptibility Data

Background: The choice of choosing right anti-microbial therapy in hospitals depends on the knowledge of local anti-microbial susceptibility profile. This retrospective study was conducted to assess the in vitro susceptibility pattern of different pathogen isolates to various antibiotics including Cefepime-Amikacin-Antibiotic resistant breakers (ARBs)* in various hospitals across the Jaipur City. Methods: To characterize the antimicrobial susceptibility pattern of different isolates from various hospitals across the Jaipur City, a retrospective, observational analysis was done for antibiogram data. A total of 1201 Gram negative isolates collected during the period from January 2017 to December 2017 were included in the study. Antibiotic sensitivity testing was done in accordance with the recommendations of Clinical Laboratory Standard Institute (CLSI) guidelines. Results: Of the total 1201 Gram negative isolates included in this study, 51.6% were from wounds and pus specimens, 40.1% were from respiratory and 8.2% from blood. P. aeruginosa (49.7%) was the most frequently isolated pathogen distantly followed by A. baumannii (21.6%), K. pneumoniae (16.6%) and E. coli (12.1%). The highest susceptibility was reported to polymyxins (100%) including Colistin and Polymyxin B, among all the tested bacteria’s and system wise. Among all the antibiotic tested, (Cefepime-Amikacin-ARBs*) sensitivity ranged for 87.9% to 52% on pathogens (E. coli, K. pneumonia, P. aeruginosa) tested from samples of skin and soft tissue, respiratory tract, blood stream, followed by Meropenem ranged for 78.4% to 55% on pathogens (E. coli, K. pneumonia, P. aeruginosa), followed by ceftazidime-tazobactam ranged for 82.7% to 58% on pathogens (E. coli, K. pneumonia, P. aeruginosa) and 22.7% sensitive for A. baumannii to Cefoperazone sulbactam. Based on pathogen type, E. coli exhibited highest overall susceptibility and the lowest was reported by A. baumannii. The susceptibility of A. baumannii ranged from 1-26% to all the tested antibiotics except polymyxins with 100% susceptibility. Conclusions: This in vitro susceptibility data suggests that Cefepime-Amikacin-ARBs* can serve as important therapeutic option for the treatment of various resistant Gram-negative bacterial infections to relieve the excess pressure on last resort antibiotics, carbapenems and other drugs including Colistin and polymyxin B. Cefepime-Amikacin-ARBs*on the basis of antimicrobial susceptibility data can be considered as an effective therapeutic option for carbapenems in treating gram negative bacterial infections, and could be considered as a broad spectrum antibiotic sparer’s like carbapenem, colistin and Polymyxin B.

scholarly journals 1181. Use of the Combination Antibiogram in the Era of MDR Gram-Negative Pathogens

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S357-S357
Author(s):  
Kenneth Klinker ◽  
Kartikeya Cherabuddi ◽  
Mark Redell ◽  
Matthew Balogh ◽  
Jill Massey ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Empiric Therapy ◽  
Multidrug Resistant ◽  
In Vitro Susceptibility ◽  
University Of Florida ◽  
Gram Negative ◽  
E Coli ◽  
Susceptibility Data ◽  
The University

Abstract Background Combinations of two or more antimicrobial agents are frequently used in empiric therapy regimens to ensure at least one agent demonstrates activity against suspected pathogens. A combination antibiogram can assess the increase in empiric coverage of a particular combination vs. either of the agents alone (i.e., percent gain). These data could assist in developing empiric regimens that may be particularly useful in settings with problematic multidrug-resistant Gram-negative pathogens. Methods An Excel-based model to construct combination antibiograms was developed to assist clinicians in evaluating institutional susceptibility data. The University of Florida Health Shands Hospital microbiology laboratory supplied susceptibility data for ceftriaxone (CFX), cefepime (CEF), ciprofloxacin (CIP), and amikacin (AMI) to assess % gain achieved with combinations for E. coli all blood isolates (n = 206) and blood isolates with an ESBL phenotype (n = 35). The same laboratory provided susceptibility data for CEF, piperacillin–tazobactam (PTZ), AMI and CIP for P. aeruginosa (all, n = 250; carbapenem-resistant (CARB-R), n = 30). Results Percent gains achieved by adding AMI or CIP to CFX and CEF to capture at least one agent exhibiting in vitro susceptibility against all blood E. coli were calculated: CFX-AMI, 16%; CFTX-CIP, 3%; CEF-AMI, 10%; CEF-CIP, 1%. The percentage gain specific to E. coli blood isolates with an ESBL phenotype ranged from 9% to 86%. The combination with the greatest percent loss against blood E. coli isolates, comparing all blood isolates to those with an ESBL phenotype, was CFX-CIP (∆-66%). Percentage gain achieved against all isolates of Pa by adding AMI or CIP to PTZ and CEF were CEF-AMI, 8%; CEF-CIP, 5%; PTZ-AMI, 15%; PTZ-CIP, 9%; percent gain of the same combinations against P. aeruginosa CARB-R isolates were 23%, 10%, 47%, and 30%, respectively. Adding AMI to either β-lactam: PTZ % S increased from 47% to 77% (+CIP) and to 94% (+AMI); CEF % S increased from 60% S to 70% (+CIP) and to 83% (+AMI). Conclusion Combination antibiogram models can assist clinicians in identifying regimens which may provide improved targeting of MDR phenotypes through calculation of percent gain. Disclosures K. Klinker, Melinta Therapeutics: Consultant, Speaker honorarium. Nabriva Therapeutics: Scientific Advisor, Consulting fee. M. Redell, Melinta Therapeutics, Inc.: Employee and Shareholder, Salary. M. Balogh, Melinta Therapeutics, Inc.: Employee and Shareholder, Salary. J. Massey, Melinta Therapeutics, Inc.: Employee and Shareholder, Salary. M. Dudley, The Medicines Company: Employee, Salary.

Synthesis, In Vitro and In Silico Studies of Indolequinone Derivatives against Clinically Relevant Bacterial Pathogens

2020 ◽  
Vol 20 (3) ◽  
pp. 192-208 ◽  
Author(s):  
Talita Odriane Custodio Leite ◽  
Juliana Silva Novais ◽  
Beatriz Lima Cosenza de Carvalho ◽  
Vitor Francisco Ferreira ◽  
Leonardo Alves Miceli ◽  
...  
Keyword(s):  
In Silico ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Mass Spectrometry Analysis ◽  
World Health ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Dione Derivative ◽  
In Silico Studies

Background: According to the World Health Organization, antimicrobial resistance is one of the most important public health threats of the 21st century. Therefore, there is an urgent need for the development of antimicrobial agents with new mechanism of action, especially those capable of evading known resistance mechanisms. Objective: We described the synthesis, in vitro antimicrobial evaluation, and in silico analysis of a series of 1H-indole-4,7-dione derivatives. Methods: The new series of 1H-indole-4,7-diones was prepared with good yield by using a copper(II)- mediated reaction between bromoquinone and β-enamino ketones bearing alkyl or phenyl groups attached to the nitrogen atom. The antimicrobial potential of indole derivatives was assessed. Molecular docking studies were also performed using AutoDock 4.2 for Windows. Characterization of all compounds was confirmed by one- and two-dimensional NMR techniques 1H and 13C NMR spectra [1H, 13C – APT, 1H x 1H – COSY, HSQC and HMBC], IR and mass spectrometry analysis. Results: Several indolequinone compounds showed effective antimicrobial profile against Grampositive (MIC = 16 µg.mL-1) and Gram-negative bacteria (MIC = 8 µg.mL-1) similar to antimicrobials current on the market. The 3-acetyl-1-(2,5-dimethylphenyl)-1H-indole-4,7-dione derivative exhibited an important effect against different biofilm stages formed by a serious hospital life-threatening resistant strain of Methicillin-Resistant Staphylococcus aureus (MRSA). A hemocompatibility profile analysis based on in vitro hemolysis assays revealed the low toxicity effects of this new series. Indeed, in silico studies showed a good pharmacokinetics and toxicological profiles for all indolequinone derivatives, reinforcing their feasibility to display a promising oral bioavailability. An elucidation of the promising indolequinone derivatives binding mode was achieved, showing interactions with important sites to biological activity of S. aureus DNA gyrase. These results highlighted 3-acetyl-1-(2-hydroxyethyl)-1Hindole- 4,7-dione derivative as broad-spectrum antimicrobial prototype to be further explored for treating bacterial infections. Conclusion: The highly substituted indolequinones were obtained in moderate to good yields. The pharmacological study indicated that these compounds should be exploited in the search for a leading substance in a project aimed at obtaining new antimicrobials effective against Gram-negative bacteria.

scholarly journals Synthesis and Antimicrobial Properties of Highly Cross-Linked pH-Sensitive Hydrogels through Gamma Radiation

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2223
Author(s):  
Moises Bustamante-Torres ◽  
Victor H. Pino-Ramos ◽  
David Romero-Fierro ◽  
Sandra P. Hidalgo-Bonilla ◽  
Héctor Magaña ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Film Formation ◽  
Antimicrobial Properties ◽  
Ph Sensitive ◽  
Scanning Calorimetry ◽  
Polymeric Systems ◽  
E Coli ◽  
High Prevalence

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.

scholarly journals Investigating In Vitro Antibacterial Activities of Medicinal Plants Having Folkloric Repute in Ethiopian Traditional Medicine

2019 ◽  
Vol 24 ◽  
pp. 2515690X1988627 ◽  
Author(s):  
Mekonnen Sisay ◽  
Negussie Bussa ◽  
Tigist Gashaw ◽  
Getnet Mengistu
Keyword(s):  
Antibacterial Activity ◽  
Medicinal Plants ◽  
Antimicrobial Agents ◽  
Bacterial Isolates ◽  
Zone Of Inhibition ◽  
Traditional Use ◽  
Gram Negative ◽  
E Coli ◽  
Slow Development

Medicinal plants are targeted in the search for new antimicrobial agents. Nowadays, there is an alarmingly increasing antimicrobial resistance to available agents with a very slow development of new antimicrobials. It is, therefore, necessary to extensively search for new agents based on the traditional use of herbal medicines as potential source. The antibacterial activity of 80% methanol extracts of the leaves of Verbena officinalis (Vo-80ME), Myrtus communis (Mc-80ME), and Melilotus elegans (Me-80ME) was tested against 6 bacterial isolates using agar well diffusion technique. In each extract, 3 concentrations of 10, 20, and 40 mg/well were tested for each bacterium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. Vo-80ME and Mc-80ME exhibited promising antibacterial activity against Staphylococcus aureus with the highest zone of inhibition being 18.67 and 26.16 mm, respectively at concentration of 40 mg/well. Regarding gram-negative bacteria, Vo-80ME exhibited an appreciable activity against Escherichia coli and Salmonella typhi. Mc-80ME displayed remarkable activity against all isolates including Pseudomonas aeruginosa with the maximum zone of inhibition being 22.83 mm. Me-80ME exhibited better antibacterial activity against E coli, but its secondary metabolites had little or no activity against other gram-negative isolates. The MIC values of Vo-80ME ranged from 0.16 to 4.00 mg/mL. The lowest MIC was observed in Mc-80ME, with the value being 0.032 mg/mL. Mc-80ME had bactericidal activity against all tested bacterial isolates. Mc-80ME showed remarkable zone of inhibitions in all tested bacterial isolates. Besides, Vo-80ME showed good antibacterial activity against S aureus, E coli, and S typhi. Conversely, Me-80ME has shown good activity against E coli only. Generally, M communis L and V officinalis have good MIC and MBC results.

scholarly journals 519. Multidrug-resistant Gram-Negative Bacteremia in Pediatric Patients: Is It Time to Change to Empiric Meropenem?

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S250-S250
Author(s):  
Kanokporn Mongkolrattanothai ◽  
Leslie Stach ◽  
Regina Orbach
Keyword(s):  
Antimicrobial Agents ◽  
Pediatric Patients ◽  
Multidrug Resistant ◽  
Suspected Sepsis ◽  
In Vitro Susceptibility ◽  
Gram Negative ◽  
Gram Negative Bacteremia ◽  
Delayed Initiation ◽  
Poor Outcomes

Abstract Background The rise of antimicrobial resistance among gram-negative (GN) pathogens has been dramatic nationally. Delayed initiation of active antimicrobial agents has been associated with poor outcomes. We aimed at evaluating the prevalence and treatment of multi-drug-resistant gram-negative (MDR-GN) bacteremia in our pediatric patients. Methods All episodes of GN bacteremia from 2017–2018 at our institution were retrospectively reviewed. GN defined as MDR in our study were carbapenem-resistant organisms (CRO), extended-spectrum β-lactamase (ESBL) producers, and GN that were resistant to cefepime and ≥2 classes of non-cephalosporin antimicrobial agents. Stenotrophomonas maltophilia was excluded. Ineffective empirical treatment (IET) is defined as an initial antibiotic regimen that is not active against the identified pathogen[s] based on in vitro susceptibility testing results. Results A total of 292 episodes of GN bacteremia were identified and 6 S. maltophilia were excluded. Of these, 29 bacteremic episodes in 26 patients were caused by MDR-GN organisms including 18 ESBL, 7 CRO, 1 ESBL and CRO, 3 non-ESBL/non-CRO cefepime-resistant MDR-GN. None of the CRO had carbapenemase genes detected. However, there was a patient with multiple sites of infection simultaneously with non-NDM CR Acinetobacter bacteremia and NDM-mediated CR-Klebsiella ventriculitis. The annual rate of MDR-GN bacteremia increased from 8% in 2017 to 12% in 2018. Almost half (48%) of episodes were community onset. Among these, all but one had underlying medical conditions with hospital exposure and most patients had central venous devices at the time of infection. 52% (15/29) episodes of MDR-GN bacteremia had IET. Despite IET, 47% (7/15) had negative blood cultures prior to initiation of effective therapy (6 ESBL and 1 P. aeruginosa). Various antibiotic regimens were used for CRO therapy as shown in Table 1. Conclusion In our institution, MDR-GN infection is increasing. As such, empiric meropenem is currently recommended in BMT or neutropenic patients with suspected sepsis. However, empiric meropenem must be used judiciously as its widely use will lead to more selection of MDR pathogens. It is essential to continue monitoring of these MDR-GN to guide appropriate empiric regimens. Disclosures All authors: No reported disclosures.

scholarly journals In Vitro Activity of Newer and Conventional Antimicrobial Agents, Including Fosfomycin and Colistin, against Selected Gram-Negative Bacilli in Kuwait

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
The Other ◽  
In Vitro Activity ◽  
Limited Data ◽  
Gram Negative ◽  
E Coli ◽  
Microbroth Dilution

Limited data are available on susceptibilities of these organisms to some of the recently made accessible antimicrobial agents. The in vitro activities of newer antibiotics, such as, ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) along with some “older” antibiotics, for example fosfomycin (FOS) and colistin (CL) were determined against selected strains (resistant to ≥ 3 antimicrobial agents) of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by Clinical and Laboratory Standards Institute microbroth dilution. 133 isolates: 46 E. coli, 39 K. pneumoniae, and 48 P. aeruginosa were tested. Results showed that E. coli isolates with MIC50/90, 0.5/1 μ g / mL for CL; 4/32 μ g / mL for FOS; 0.25/32 μ g / mL for C/T; 0.25/8 μ g / mL for CZA, exhibited susceptibility rates of 95.7%, 97.8%, 76.1%, and 89.1%, respectively. On the other hand, K. pneumoniae strains with MIC50/90, 0.5/1 μ g / mL for CL; 256/512 μ g / mL for FOS; 2/128 μ g / mL for C/T; 0.5/128 μ g / mL for CZA showed susceptibility rates of 92.3%, 7.7%, 51.3%, and 64.1%, respectively. P. aeruginosa isolates with MIC50/90, 1/1 μ g / mL for CL; 128/128 μ g / mL for C/T; 32/64 μ g / mL for CZA presented susceptibility rates of 97.9%, 33.3%, and 39.6%, respectively. Higher MICs were demonstrated against most of the antibiotics. However, CL retained efficacy at low MICs against most of the isolates tested.

scholarly journals 2214. Comparison of Cefepime–Zidebactam (WCK 5222), Ceftazidime–Avibactam, and Ceftolozane–Tazobactam Tested Against Gram-Negative Organisms Causing Pneumonia in United States Hospitals in 2018

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S755-S755 ◽  
Author(s):  
Helio S Sader ◽  
Cecilia G Carvalhaes ◽  
Rodrigo E Mendes ◽  
Mariana Castanheira ◽  
Robert K Flamm
Keyword(s):  
Therapeutic Option ◽  
High Dose ◽  
Gram Negative ◽  
E Coli ◽  
Highly Active ◽  
Medical Centers ◽  
Carbapenem Resistant ◽  
Gram Negative Organisms ◽  
Dual Mechanism

Abstract Background Zidebactam (ZID) is a bicyclo-acyl hydrazide antibiotic with a dual mechanism of action: selective Gram-negative PBP2 binding and β-lactamase inhibition. We evaluated the frequency and antimicrobial susceptibility (S) of Gram-negative bacilli (GNB) isolated from patients with pneumonia in US hospitals. Methods All 3,086 clinical isolates were consecutively collected from patients hospitalized with pneumonia (1/patient) in 29 US medical centers in 2018, and the GNB (n = 2,171) were S tested against cefepime (FEP)-ZID (1:1 ratio) and comparators by reference broth microdilution methods. The FEP S breakpoint of ≤8 mg/L (CLSI, high dose) was applied to FEP-ZID for comparison purposes. An FEP-ZID S breakpoint of ≤64 mg/L has been proposed for non-fermentative GNB based on pharmacokinetic/pharmacodynamic target attainment and was applied. Enterobacterales (ENT) isolateswere screened for β-lactamase genes by whole-genome sequencing. Results GNB represented 70.3% of the collection, and the most common GNB were P. aeruginosa (PSA; 34.9% of GNB), K. pneumoniae (10.9%), E. coli (9.7%), S. marcescens (7.7%), and S. maltophilia (XM; 6.4%). FEP-ZID was highly active against PSA (MIC50/90, 2/8 mg/L; 98.8% and 99.9% inhibited at ≤8 and ≤16 mg/L, respectively; highest MIC, 32 mg/L), including resistant subsets (table). Among comparators, colistin (99.6%S), ceftazidime–avibactam (CAZ-AVI; 95.2%S), and ceftolozane–tazobactam (C-T; 94.5%S) were the most active compounds against PSA. FEP-ZID inhibited all ENT at ≤4 mg/L, including ESBL-producers (MIC90, 0.25 mg/L) and carbapenem-resistant ENT (MIC90, 4 mg/L). The most active comparators against ENT were CAZ-AVI (99.9%S), amikacin (98.5%S), and meropenem (MEM; 98.3%S). FEP-ZID inhibited 75.0% and 97.9% of XM isolates at ≤8 and ≤16 mg/L, respectively (highest MIC, 64 mg/L). The only other compounds active against XM were co-trimoxazole (MIC50/90, ≤0.12/2 mg/L; 95.7%S) and levofloxacin (MIC50/90, 1/2 mg/L; 70.7%S). FEP-ZID inhibited 71.0% and 98.9% of A. baumannii isolates at ≤8 and ≤64 mg/L,, respectively. Conclusion FEP-ZID showed potent in vitro activity against GNB causing pneumonia in US hospitals and may represent a valuable therapeutic option for these difficult-to-treat infections Disclosures All authors: No reported disclosures.

scholarly journals Synthesis and Antimicrobial Evaluations of Sulfur Inserted Fluoro-Benzimidazoles

2021 ◽  
Vol 33 (7) ◽  
pp. 1525-1529
Author(s):  
Parmesh Kumar Dwivedi ◽  
Devdutt Chaturvedi
Keyword(s):  
Antimicrobial Agents ◽  
Bacterial Strains ◽  
Substituted Anilines ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
New Compounds ◽  
Derivatives Of ◽  
Multiple Step

A new series of fluorinated sulfur inserted benzimidazole analogues Za-i were synthesized and characterized. The new compounds were screened for their antimicrobial and antioxidant potential. The synthesized compounds were obtained by multiple step synthesis, initiating from the synthesis of 5-(difluoromethoxy)-1H-benzimidazole-2-thiol X. The compounds Ya-i prepared by reacting differently substituted anilines with chloroacetylchloride and triethylamine in DMF. Finally, the compound X was reacted with different derivatives of 2-chloro-N-phenylacetamide resulting in formation of titled compounds Za-i. The synthesized compounds (Za-Zi) were characterized by spectral analysis viz.1H & 13C NMR, mass spectra, elemental analysis and IR. The in vitro antimicrobial potential against Gram-positive (S. aureus and E. faecalis) and Gram-negative bacterial (E. coli and P.aeruginosa) strains as well as fungi (A. niger and C. albicans) was recorded for the obtained compounds. Some of the compounds exhibited encouraging results (in MIC) against Gram-positive and Gram-negative bacterial strains. These studies thus suggest that the designed sulfur inserted fluoro-benzimidazoles scaffold may serve as new promising template for further amplification as antimicrobial agents.

scholarly journals Staphylococcus aureus biofilm and the role of bacteriophages in its eradication

2018 ◽  
Vol 72 ◽  
pp. 101-107
Author(s):  
Natalia Łubowska ◽  
Lidia Piechowicz
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Methicillin Resistance ◽  
Therapeutic Option ◽  
Resistant Bacteria ◽  
Prosthetic Heart Valves ◽  
Biofilm Structure ◽  
Implanted Devices

The ability to form biofilm is an important virulence factor of many microorganisms. Infections involving biofilms account for approx. 65% of all human infections. Biofilms may develop on intravascular catheters or implanted devices such as prosthetic heart valves. Implanted devices are covered by biofilm and become reservoirs of microorganisms which can be a cause of persistent infections (endocarditis, deep tissue abscesses, septic arthritis, and osteomyelitis). Treatment of infections caused by biofilm-growing cells is linked to a high risk of failure due to an extreme resistance to antimicrobial agents and increased capacity to evade the immune responses. A large number of biofilm-associated infections involve Staphylococcus aureus. Treatment of staphylococcal infections is a great challenge for clinicians because of the presence of various mechanisms of resistance to antibiotics in S. aureus, for example methicillin resistance and biofilm production. Therapeutic difficulties related with antibiotic-resistant bacteria and limitations in research on new antimicrobials were the reasons that nearly 100 years after discovery, bacteriophages caught the attention of scientists around the world as a new therapeutic option for bacterial infections. Numerous in vitro studies on S. aureus strains showed that phages can both prevent biofilm formation and contribute to the elimination of bacteria from the mature biofilm structure. The major role in biofilm eradication play depolymerases produced by some phages which facilitate their penetration into the inner layers of biofilm by disturbing the biofilm structure. This leads to the conclusion that bacteriophages treatment might become a new strategy in the prevention and eradication of infectious bacterial biofilms, including these formed by S. aureus.

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