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

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.

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

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.

scholarly journals Spectrum of Imipenem and Meropenem Susceptibilities amongst Gram Negative Rods

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

Effects of Gram-negative Bacteria on Ureteral Structure and Function

1968 ◽  
Vol 99 (5) ◽  
pp. 539-550 ◽  
Author(s):  
Luis Grana ◽  
William L. Donnellan ◽  
Orvar Swenson
Keyword(s):  
Structure And Function ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
And Function

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

2009 ◽  
Vol 3 (11) ◽  
pp. 843-848 ◽  
Author(s):  
Lucky H. Moehario ◽  
Enty Tjoa ◽  
Ariyani Kiranasari ◽  
Ika Ningsih ◽  
Yeva Rosana ◽  
...  
Keyword(s):  
Clinical Microbiology ◽  
Klebsiella Oxytoca ◽  
Enterobacter Aerogenes ◽  
Salmonella Typhi ◽  
Alcaligenes Faecalis ◽  
Gram Negative Bacteria ◽  
Community Settings ◽  
Gram Negative ◽  
E Coli ◽  
Blood Specimens

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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