Trends in antimicrobial susceptibility of Gram-negative bacteria isolated from blood in Jakarta from 2002 to 2008

Background: This study examined the susceptibility of Gram-negative bacteria in the bloodstream to antimicrobials with the aim of providing information relevant to the guidance of therapy. Methodology: Blood specimens received by the Laboratory of Clinical Microbiology, Faculty of Medicine, University of Indonesia, from 2002 to 2008, were analyzed for the presence of Gram-negative bacteria and their susceptibility to four antibiotic groups frequently administered in hospitals and community settings. Results: During the seven-year period leading up to 2008, approximately 68% of Gram-negative bacteria were identified among all positive isolates from blood specimens. The eight most frequent species found were Acinetobacter anitratus (25.8%), Pseudomonas aeruginosa (19.5%), Klebsiella pneumoniae subsp. pneumoniae (14.5%), Enterobacter aerogenes (8%), Salmonella Typhi (7.5%), Escherichia coli (6.2%), Alcaligenes faecalis (5.6%) and Klebsiella oxytoca (3.2%). At 80% susceptibility or greater, Ceftriaxone and Cefotaxime were active only on E. coli and S. Typhi. Cefepime demonstrated activity on all eight species tested except K. pneumonia while Amikacin showed activity against five species, A. faecalis, E. aerogenes, E. coli, K. pneumoniae subsp. pneumoniae and S. Typhi. Gentamycin was active against three species: E. aerogenes, K. oxytoca and S. Typhi. Ciprofloxacin and Levofloxacin significantly differed in their spectrum: while Ciprofloxacin was active against four of the eight species tested (E. aerogenes, E. coli, K. oxytoca, and S. Typhi ), Levofloxacin was similar to Cefepime and was active against all eight species except K. pneumoniae subsp. pneumonia. Conclusions: Since antimicrobials are broadly used in Jakarta, it is important that the information captured in this study be disseminated.

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Synthesis, Characterization and Antimicrobial Activities of Co (III) and Fe (III) Complexes of Imino-N-heterocyclic Carbenes Ligands

Chemical Science International Journal ◽

10.9734/csji/2021/v30i630238 ◽

2021 ◽

pp. 59-67

Author(s):

Samaila Abubakar ◽

Musa Muktari ◽

Rejoice Atiko

Keyword(s):

Escherichia Coli ◽

Salmonella Typhi ◽

Antimicrobial Activities ◽

Heterocyclic Carbenes ◽

Gram Negative Bacteria ◽

Disc Diffusion ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria

The synthesis and antimicrobial application of Co (III) and Fe (III) complexes of imine functionalized N-heterocyclic carbene (Imino-NHC) ligands is reported. The ligand precursors 1-(2-[(hydroxyl-benzylidene)-amino]-ethyl)-3-R-3H-imidazol-1-ium bromide where R = pyridyl (1a) and benzyl (1b) have been reported in our previous work. The in-situ generated ligands of 1a and 1b have been successfully coordinated to CoBr2 and [FeI(Cp)(CO)2] leading to the isolation of air-stable N^C^N^O four coordinate Co(III) complex 2 and a six-coordinate Fe(III) complex 3. The synthesised complexes were both found to be NMR inactive hence were characterize using FTIR and LRMS. The complexes were screened for antimicrobial activities against four gram-negative bacteria Escherichia Coli (E-coli), Shigella, Klebsiella pneumoniae (K. Pneumoniae) and Salmonella typhi (S. typhi) and a gram positive bacteria Staphylocossus aureus (S. aureus). The antimicrobial test was conducted using disc diffusion methods and based on the concentrations of 100, 200, 300, 400 and 500 µg/ mL, significant activities were recorded for both cobalt and the iron complexes.

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Exogenous Production of N-acetylmuramyl-L Alanine Amidase (LysM2) from Siphoviridae Phage Affecting Anti-Gram-Negative Bacteria: Evaluation of Its Structure and Function

Avicenna Journal of Medical Biotechnology ◽

10.18502/ajmb.v14i1.8169 ◽

2022 ◽

Author(s):

Morteza Miri ◽

Sepideh Yazdianpour ◽

Shamsozoha Abolmaali ◽

Shakiba Darvish Alipour Astaneh

Keyword(s):

In Silico ◽

Alpha Helix ◽

Salmonella Typhi ◽

Structure And Function ◽

Gram Negative Bacteria ◽

Gene Encoding ◽

Gram Negative ◽

E Coli ◽

Antigenic Properties ◽

And Function

Background: To obtain endolysin with impact(s) on gram-negative bacteria as well as gram-positive bacteria, N-acetylmuramyl L-alanine-amidase (MurNAc-LAA) from a Bacillus subtilis-hosted Siphoviridae phage (SPP1 phage, Subtilis Phage Pavia 1) was exogenously expressed in Escherichia coli (E. coli). Methods: The sequences of MurNAc-LAA genes encoding peptidoglycan hydrolases were obtained from the Virus-Host database. The sequence of MurNAc-LAA was optimized by GenScript software to generate MurNAc-LAA-MMI (LysM2) for optimal expression in E. coli. Furthermore, the structure and function of LysM2 was evaluated in silico. The optimized gene was synthesized, subcloned in the pET28a, and expressed in E. coli BL21(DE3). The antibacterial effects of the protein on the peptidoglycan substrates were studied. Results: LysM2, on 816 bp gene encoding a 33 kDa protein was confirmed as specific SPP1 phage enzyme. The enzyme is composed of 271 amino acids, with a half-life of 10 hr in E. coli. In silico analyses showed 34.2% alpha-helix in the secondary structure, hydrophobic N-terminal, and lysine-rich C-terminal, and no antigenic properties in LysM2 protein. This optimized endolysin revealed impacts against Proteus (sp) by turbidity, and an antibacterial activity against Klebsiella pneumoniae, Salmonella typhi-murium, and Proteus vulgaris in agar diffusion assays. Conclusion: Taken together, our results confirmed that LysM2 is an inhibiting agent for gram-negative bacteria.

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Spectrum of Imipenem and Meropenem Susceptibilities amongst Gram Negative Rods

10.53350/pjmhs211571807 ◽

2021 ◽

Vol 15 (7) ◽

pp. 1807-1809

Author(s):

Sadia Ikram ◽

Anila Errum ◽

Asma Inam ◽

Farrukh Sarfaraz ◽

Sadia Majeed ◽

...

Keyword(s):

Susceptibility Testing ◽

Carbapenem Resistance ◽

Salmonella Typhi ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Klebsiella Species ◽

Gram Negative ◽

E Coli ◽

Microbiological Techniques ◽

Resistance Spectrum

Aim: To compare the resistance amongst Gram negative bacteria against imipenem and meropenem. Study Design: Prospective, non-randomized, descriptive study. Place and Duration of Study: Department of Microbiology, Mughal Laboratories, Lahore from 1stJuly 2019 to 31stDecember 2019. Methodology: One hundred culture samples received, bacteria isolated and their susceptibilities to imipenem and meropenem were compared. Organisms were recognized by the microbiological techniques according to the current standards and susceptibility testing was done according to the guidelines of Clinical and Laboratory Standards Institute (CLSI) 2020by using Kirby Bauer Disc diffusion method. Results: Salmonella typhi, Citrobacter species and Proteus species were 100% sensitive to imipenem. The rest of bacterial isolates had sensitivities to E. coli 88%, Acinetobacter 80%, Klebsiella species 67% and Peudomonas species 64%. The meropenem is highly resistant in all the bacteria as compared to imipenem. Conclusion: Increasing the trend of carbapenem resistance amongst Gram negative bacteria excluding Salmonella typhi was recorded. Key words: Gram negative rods, Resistance, Spectrum

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Dissemination of carbapenem resistance and plasmids encoding carbapenemases in Gram-negative bacteria isolated in India

JAC-Antimicrobial Resistance ◽

10.1093/jacamr/dlab015 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Prasanth Manohar ◽

Sebastian Leptihn ◽

Bruno S Lopes ◽

Ramesh Nachimuthu

Keyword(s):

Resistance Genes ◽

Tamil Nadu ◽

Klebsiella Oxytoca ◽

Public Health Problem ◽

Carbapenem Resistance ◽

Achromobacter Xylosoxidans ◽

Gram Negative Bacteria ◽

Gram Negative ◽

E Coli ◽

Diagnostic Centre

Abstract Background Carbapenem resistance in Gram-negative bacteria is an ongoing public health problem of global dimensions leaving very few treatment options for infected patients. Objectives To study the dissemination of plasmid-borne carbapenemase genes in Gram-negative bacteria from a diagnostic centre in Tamil Nadu, India. Methods A total of 151 non-repetitive isolates belonging to 10 genera were collected between January 2015 and December 2016 from a diagnostic centre in Tamil Nadu. The isolates included Escherichia coli (n = 57), Klebsiella pneumoniae (n = 45), Pseudomonas aeruginosa (n = 10), Salmonella Typhi (n = 8), Enterobacter cloacae (n = 8), Acinetobacter baumannii (n = 7), Serratia marcescens (n = 5), Achromobacter xylosoxidans (n = 5), Proteus mirabilis (n = 5), Klebsiella oxytoca (n = 5) and Elizabethkingia meningoseptica (n = 1). Results Of the 151 isolates, 71% (n = 107) and 68% (n = 103) were found to be resistant to meropenem and imipenem, respectively. The most prevalent β-lactamase gene was blaNDM-1 (n = 22), followed by blaOXA-181 (n = 21), blaGES-1 (n = 11), blaOXA-51 (n = 9), blaGES-9 (n = 8), blaOXA-23 (n = 7) and blaIMP-1 (n = 3). We also observed blaOXA-23 in E. coli (n = 4), and three K. pneumoniae were positive for both, blaOXA-23 and blaOXA-51. Plasmid incompatibility (inc/rep) typing results showed that the resistance genes (n = 11) were present in the isolates carrying plasmid-types IncX, IncA/C, IncFIA-FIB and IncFIIA. The plasmid-borne resistance genes in E. coli and K. pneumoniae were transferred to susceptible E. coli AB1157. Conclusions This study highlights the prevalence of carbapenem resistance and the acquisition of plasmid-borne carbapenemase genes in Gram-negative bacteria isolated at this centre.

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The growth influence of Escherichia coli co-cultured with other selected gram negative bacteria

Journal of Bio-Science ◽

10.3329/jbs.v27i0.44675 ◽

2019 ◽

Vol 27 ◽

pp. 101-108

Author(s):

OA Oyewole ◽

A Hamidu ◽

IO Egbewole ◽

R Adewole ◽

OE Oladoja

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Salmonella Typhi ◽

Shigella Dysenteriae ◽

Gram Negative Bacteria ◽

Proteus Vulgaris ◽

Macconkey Agar ◽

Gram Negative ◽

E Coli ◽

Positive Growth

This study examined the influence of Escherichia coli on the growth of other selected Gram negative bacteria (Klebsiella pneumoniae, Shigella dysenteriae, Salmonella typhi, Pseudomonas aeruginosa and Proteus vulgaris). Cultures of each bacterium at 0, 24, 48 and 72 hours of incubation were plated on MacConkey agar. Colonies that developed were counted while the optical densities were determined at 0, 24, 48 and 72 hours using spectrophotometry. Each bacterium was co-cultured with E. coli and their growth was determined using culturing method and spectrophotometry. The result showed an increase in growth in the cultures of each isolate co-cultured with E. coli when compared with single bacterium culture with the exception of P. aeruginosa. The result of this study revealed a positive growth influence between E. coli and K. pneumoniae, S. dysenteriae, S. typhi, and P. vulgaris, except for P. aeruginosa that showed a decrease in growth. J. bio-sci. 27: 101-108, 2019

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A Prospective Study on Neonatal Sepsis in a Tertiary Hospital, Nepal

Journal of Pure and Applied Microbiology ◽

10.22207/jpam.15.4.66 ◽

2021 ◽

Author(s):

Ranjit Sah ◽

Suraj Bhattarai ◽

Srijana Basnet ◽

Bharat Mani Pokhrel ◽

Niranjan Prasad Shah ◽

...

Keyword(s):

Neonatal Sepsis ◽

Early Onset ◽

Late Onset ◽

Enterobacter Aerogenes ◽

Gram Negative Bacteria ◽

Acinetobacter Baumanii ◽

Gram Negative ◽

E Coli ◽

Late Onset Sepsis ◽

A Prospective Study

About 20 % of neonates develop sepsis and among them approximately 1% die due to sepsis-related causes. Bacterial pathogens are the commonest cause of neonatal sepsis which is either early-onset (<72 hours of age) or late-onset (>72 hours). Little is known about the epidemiology and antimicrobial susceptibility pattern of sepsis causing bacterial pathogens in Nepal. A prospective study was carried out among neonates suspected to have sepsis and admitted to Tribhuwan University Teaching Hospital from January to December 2016. Clinical suspicion of sepsis was made based on clinical findings and laboratory parameters, later confirmed by isolation of organisms in blood culture. Drug resistance pattern of Gram-positive and Gram-negative bacteria were studied by standard methods. Meropenem resistant Gram-negative bacteria were processed for the detection of β-lactamases and resistant genes were detected by X-pert Carba-R (Cepheid) Assays. Of 372 neonates with clinically suspected sepsis, 132 (35.4%) had blood culture positivity, with 47% early-onset and 53% late-onset sepsis. Coagulase-negative Staphylococcus aureus (CONS) was the most common (37.9%) etiological agent followed by Klebsiella pneumoniae (12.9%). Of all 132 isolates, 81 (61.3%) were Gram-positive of which 22 (27.2%) were multi-drug resistant (MDR), three (3.7%) were methicillin-resistant S. aureus (MRSA), and 14 (17.2%) were methicillin-resistant CoNS; and 50 (37.8%) were Gram-negative of which 26 (52%) were MDR and 29 (58%) were resistant to β-lactamases. The blaKPC gene was detected in four isolates of K. pneumoniae, two of E. coli, one ABC (Acinetobacter baumanii complex), and one Enterobacter aerogenes whereas blaNDM gene was detected in one isolate of K. pneumoniae, two of E. coli, two Pseudomonas aeruginosa, one Acinetobacter baumanii complex, and one Enterobacter aerogenes. Overall mortality due to sepsis-related causes was 7.6% (10 of 132). One-third of clinically suspected neonatal sepsis cases were culture positive. Late-onset sepsis was more common than early onset. CoNS was the predominant bacterial isolate followed by Klebsiella pneumoniae, with high rates of multi-drug resistance.

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In Vitro Susceptibilities of Gram-Negative Bacteria Isolated from Hospitalized Patients in Four European Countries, Canada, and the United States in 2000-2001 to Expanded-Spectrum Cephalosporins and Comparator Antimicrobials: Implications for Therapy

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.47.10.3089-3098.2003 ◽

2003 ◽

Vol 47 (10) ◽

pp. 3089-3098 ◽

Cited By ~ 26

Author(s):

Richard P. Wenzel ◽

Daniel F. Sahm ◽

Clyde Thornsberry ◽

Deborah C. Draghi ◽

Mark E. Jones ◽

...

Keyword(s):

United States ◽

Antimicrobial Agents ◽

Klebsiella Oxytoca ◽

Enterobacter Aerogenes ◽

The United States ◽

Hospitalized Patients ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Hospital Acquired

ABSTRACT Access to current antimicrobial agent surveillance data is an important prerequisite for the optimal management of patients with hospital-acquired infections. The present study used data collected in 2000 to 2001 from 670 laboratories in Europe (France, Germany, Italy, and Spain), Canada, and the United States to report on the in vitro activities of ceftriaxone, cefotaxime, and comparative agents against >125,000 isolates of gram-negative bacteria from hospitalized patients. All but two isolates of Enterobacteriaceae (one isolate of Proteus mirabilis from France and one isolate of Morganella morganii from Canada) were susceptible to imipenem. The susceptibility of Escherichia coli to ceftriaxone or cefotaxime was ≥97% in each country, and for P. mirabilis, susceptibility was 99% in each country except Italy. In contrast, susceptibility of E. coli to ciprofloxacin varied from 80.5% (Spain) to 94.0% (France); levofloxacin susceptibility ranged from 75.2% (Spain) to 91.6% (United States). Among Klebsiella pneumoniae and Klebsiella oxytoca isolates, ceftriaxone and cefotaxime susceptibilities ranged from 86.6 to 98.7% and 83.5 to 99.7%, respectively, depending upon the country. Considerable geographic variation in the susceptibilities (generally 85 to 95% susceptible) of Serratia marcescens and M. morganii to ceftriaxone and cefotaxime were observed. For S. marcescens, susceptibility to piperacillin-tazobactam varied from 81.5% (France) to 94.1% (Italy) and susceptibility to ciprofloxacin ranged from 66.2% (Germany) to 90.7% (Spain). Enterobacter cloacae and Enterobacter aerogenes were less susceptible to ceftriaxone and cefotaxime than were the other species of Enterobacteriaceae studied. The present study demonstrated that established parenteral expanded-spectrum cephalosporin antimicrobial agents retain significant in vitro activity against many clinically important gram-negative pathogens.

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Disinfection of Fruits with Activated Water

JOURNAL OF ADVANCES IN AGRICULTURE ◽

10.24297/jaa.v10i0.8462 ◽

2019 ◽

Vol 10 ◽

pp. 1864-1872

Author(s):

Prof. Teodora P. Popova

Keyword(s):

Antimicrobial Activity ◽

Aqueous Solutions ◽

Antimicrobial Properties ◽

The Other ◽

Gram Negative Bacteria ◽

High Antimicrobial Activity ◽

Gram Negative ◽

E Coli ◽

Number Of Microorganisms ◽

Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

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Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

International Journal of Antibiotics and Probiotics ◽

10.31405/ijap.1-2.17.03 ◽

2017 ◽

Vol 1 (2) ◽

pp. 48-60

Author(s):

A.G. Salmanov ◽

A.V. Rudenko

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Staphylococcus Epidermidis ◽

Klebsiella Oxytoca ◽

Enterobacter Aerogenes ◽

Enterobacter Cloacae ◽

Proteus Vulgaris ◽

Providencia Rettgeri ◽

E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

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Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

Current Bioactive Compounds ◽

10.2174/1573407215666190124115010 ◽

2020 ◽

Vol 16 (4) ◽

pp. 481-488

Author(s):

Heli Sanghvi ◽

Satyendra Mishra

Keyword(s):

Antibacterial Activity ◽

Gram Negative Bacteria ◽

Pyrazole Derivatives ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Curcumin Derivatives ◽

Structure Activity ◽

Electron Donating Groups ◽

Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

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