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Papers by kamal azizi barjini

DOAJ (DOAJ: Directory of Open Access Journals), Dec 1, 2013

Background & aim: Pseudomonas aeruginosa is an opportunistic nosocomial pathogen that due to havi... more Background & aim: Pseudomonas aeruginosa is an opportunistic nosocomial pathogen that due to having intrinsic and acquired resistance to common antibiotics, mortality due to infections is very common. Therefore, early and accurate identification of bacteria could be effective in controlling infections and deaths. The aim of this study was to evaluate the use of a rapid method with high sensitivity and specificity based on polymerase chain reaction using gene-specific primers quorum sensing LasI system for detection of bacteria. Methods: In this study, the comparison between the results of culture and PCR for the diagnosis of Pseudomonas aeruginosa in clinical samples and other bacterial species were carried out. 40 strains of Pseudomonas aeruginosa from isolated clinical specimens were identified and confirmed by biochemical tests. LasI gene specific primers were designed using bioinformatics analysis. Sequence of this gene was amplified techniques after extraction of bacterial genome. The specificity of PCR tests with DNA from of different species, Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Vibrio cholerae were evaluated. A different dilution of the bacterial genome of Pseudomonas aeruginosa was used in PCR to evaluate the sensitivity of primer. Data were analyzed by t-test Results: The results indicated that the PCR test result was positive for all strains of P. aeruginosa isolates; however, PCR test results were negative for the four other bacteria. Even at 10-5 Pseudomonas aeruginosa genome concentration, PCR test was positive for all isolated strains Conclusion: This study showed that the primers designed for detection of Pseudomonas aeruginosa using PCR, had higher sensitivity and specificity compared to previous methods.

Protein & Peptide Letters, 2015

Probiotics and Antimicrobial Proteins, Apr 4, 2012

In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance... more In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance to conventional antibiotics. Therefore, generation of new antibiotics to control and reduce the effects of these pathogens is urgently needed. Antimicrobial peptides and proteins are important members of the host defense system in eukaryotes. These peptides are potent, broad-spectrum antibiotics that demonstrate potential as novel and alternative therapeutic agents for the treatment of drug-resistant infections. Accordingly, we evaluated two hybrid peptides CM11 (WKLFKKILKVL-NH2) and CM15 (KWKLFKK IGAVLKVL-NH2) on five important pathogenic bacteria. These peptides are short cecropin-melittin hybrid peptides obtained through a sequence combination approach, which are highly effective to inhibit the growth of important pathogenic bacteria. The activity of these two cationic peptides (CM11 and CM15) in different concentrations (2-64 mg/L) was investigated against standard and clinical isolates of important hospital infection bacteria by measuring MIC, MBC, and bactericidal assay. These peptides demonstrated the same ranges of inhibitory values: The organisms in early 24 h were more susceptible to polycationic peptides (MIC: 8 mg/L and MBC 32 mg/L), but after 48 h the MIC and MBC remained constant for the CM11 peptide. Bactericidal assay showed that all bacteria strains did not have any growth in agar plates after 40 min. The result showed that these two peptides are more effective than other peptides.

World Journal of Microbiology and Biotechnology, 2014

Antimicrobial Agents and Chemotherapy, 1974

The in vitro activities of verdamicin and gentamicin were studied in parallel against 1,049 bacte... more The in vitro activities of verdamicin and gentamicin were studied in parallel against 1,049 bacterial isolates. Verdamicin demonstrated activity similar to that of gentamicin against members of the family Enterobacteriaceae and against Pseudomonas aeruginosa at 2 and 8 gg/ml, respectively. Proteus rettgeri and Providencia stuartii were notably more susceptible to verdamicin. The new aminoglycoside was also highly active against staphylococci but was not effective against group D streptococci. Verdamicin (SCH 15666), a new water-soluble aminoglycoside antibiotic produced by a new species of micromonospora, M. grisea NRRL 3800, is the dehydro analogue of gentamicin C2 (P.

ABSTRACT In recent years, the widespread use of conventional antibiotics has led to many microbia... more ABSTRACT In recent years, the widespread use of conventional antibiotics has led to many microbial pathogens becoming resistant to these antibiotics. Therefore, the development of novel and alternative therapeutic strategies for controlling and reducing the effects of these pathogens is urgently needed. Studies have shown that antimicrobial peptides (AMPs) and proteins are important members of the host defense system in eukaryotes. These peptides are potent agents with broad-spectrum activity against many Gram-positive and Gram-negative bacteria. In this review, we discuss the diversity, the broad spectrum of antimicrobial activity and related properties of AMPs that could be exploited for their application as potential drug candidates in therapeutic strategies against multiresistant pathogens.

With the growing microbial resistance to conventional antimicrobial agents, the development of no... more With the growing microbial resistance to conventional antimicrobial agents, the development of novel and alternative therapeutic strategies are vital. During recent years novel peptide antibiotics with broad spectrum activity against many Gram-positive and Gramnegative bacteria have been developed. In this study, antibacterial activity of CM11 peptide (WKLFKKILKVL-NH2), a short cecropin-melittin hybrid peptide, is evaluated against antibiotic-resistant strains of Klebsiella pneumoniae and Salmonella typhimurium as two important pathogenic bacteria. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal killing assay were utilized with different concentrations (2-128 mg/L) of peptide. To evaluate cytotoxic effect of peptide, viability of RAJI, Hela, SP2/0, CHO, LNCAP cell lines and primary murine macrophage cells were also investigated with MTT assay in different concentrations (3-24 and 0.5-16 mg/L, respectively). MICs of K. pneumoniae and S. typhimurium isolates were in range of 8-16 and 4-16 mg/L, respectively. In bactericidal killing assay no colonies were observed at 2X MIC for K. pneumoniae and S. typhimurium isolates after 80-90 min, respectively. Despite the fact that CM11 reveals no significant cytotoxicity on RAJI, Hela, SP2/0, and CHO cell lines beneath 6 mg/L at first 24 and 48 h, the viability of LNCAP cells are about 50 % at 3 mg/L, which indicates strong cytotoxicity of the peptide. In addition, macrophage toxicity by MTT assay showed that LD 50 of CM11 peptide is 12 lM (16 mg/L) after 48 h while in this concentration after 24 h macrophage viability was about 70 %.

"In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistanc... more "In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance to conventional antibiotics. Therefore, generation of new antibiotics to control and reduce the effects of these pathogens is urgently needed. Antimicrobial peptides and proteins are important members of the host defense system in eukaryotes. These peptides are potent, broad-spectrum antibiotics that demonstrate potential as novel and alternative therapeutic agents for the treatment of drug-resistant infections. Accordingly, we evaluated two hybrid peptides CM11 (WKLFKKILKVL-NH2) and CM15 (KWKLFKKIGAVLKVL-NH2) on five important pathogenic bacteria. These peptides are short cecropin–melittin hybrid peptides obtained through a sequence combination approach, which are highly effective to inhibit the growth of important pathogenic bacteria. The activity of these two cationic peptides (CM11 and CM15) in different concentrations (2–64 mg/L) was investigated against standard and clinical isolates of important hospital infection bacteria by measuring MIC, MBC, and bactericidal assay. These peptides
demonstrated the same ranges of inhibitory values: The organisms in early 24 h were more susceptible to polycationic peptides (MIC: 8 mg/L and MBC 32 mg/L), but after 48 h the MIC and MBC remained constant for the CM11 peptide. Bactericidal assay showed that all bacteria strains did not have any growth in agar plates after 40 min. The result showed that these two peptides are more effective than other peptides"

Thermophilic processes appear more stable, rapid and less expensive and facilitate reactant activ... more Thermophilic processes appear more stable, rapid and less expensive and facilitate reactant activity and product recovery. Amylases have a quarter of the world enzyme market and thermostable alpha-amylases possess extensive commercial applications. Since little work has been done on strain isolation, growth and enzyme yield optimization, the level of thermophilic enzyme production remains relatively low. Therefore, large scale exploitation of thermophiles requires further intensive and integrated work. The present study describes isolation of an a-amylase producing bacillus from soil. The isolated bacillus was identified and named as Bacillus licheniformis Shahed-07. The strain was cultured in liquid media to produce a-amylase. The enzyme production conditions of the newly isolated bacillus revealed that the maximum enzyme production after 26 h of cultivation at pH 7.0 and 50°C. 0.5% tryptophan in production medium enhanced the enzyme productivity to two fold whereas peptone and lysin at 0.5% level showed a strong repression. Crude a-amylase characterization revealed that optimum activity was at pH 7.5 and 70°C. The crude enzyme was stable for 24 h at pH range of
6-7 at 70°C. Enzyme activity increased with temperature within the range of 40-70°C. The Bacillus licheniformis Shahed-07 strain produced thermostable a-amylase with characteristics suitable for application in starch processing and food industries.

DOAJ (DOAJ: Directory of Open Access Journals), Dec 1, 2013

Background & aim: Pseudomonas aeruginosa is an opportunistic nosocomial pathogen that due to havi... more Background & aim: Pseudomonas aeruginosa is an opportunistic nosocomial pathogen that due to having intrinsic and acquired resistance to common antibiotics, mortality due to infections is very common. Therefore, early and accurate identification of bacteria could be effective in controlling infections and deaths. The aim of this study was to evaluate the use of a rapid method with high sensitivity and specificity based on polymerase chain reaction using gene-specific primers quorum sensing LasI system for detection of bacteria. Methods: In this study, the comparison between the results of culture and PCR for the diagnosis of Pseudomonas aeruginosa in clinical samples and other bacterial species were carried out. 40 strains of Pseudomonas aeruginosa from isolated clinical specimens were identified and confirmed by biochemical tests. LasI gene specific primers were designed using bioinformatics analysis. Sequence of this gene was amplified techniques after extraction of bacterial genome. The specificity of PCR tests with DNA from of different species, Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Vibrio cholerae were evaluated. A different dilution of the bacterial genome of Pseudomonas aeruginosa was used in PCR to evaluate the sensitivity of primer. Data were analyzed by t-test Results: The results indicated that the PCR test result was positive for all strains of P. aeruginosa isolates; however, PCR test results were negative for the four other bacteria. Even at 10-5 Pseudomonas aeruginosa genome concentration, PCR test was positive for all isolated strains Conclusion: This study showed that the primers designed for detection of Pseudomonas aeruginosa using PCR, had higher sensitivity and specificity compared to previous methods.

Protein & Peptide Letters, 2015

Probiotics and Antimicrobial Proteins, Apr 4, 2012

In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance... more In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance to conventional antibiotics. Therefore, generation of new antibiotics to control and reduce the effects of these pathogens is urgently needed. Antimicrobial peptides and proteins are important members of the host defense system in eukaryotes. These peptides are potent, broad-spectrum antibiotics that demonstrate potential as novel and alternative therapeutic agents for the treatment of drug-resistant infections. Accordingly, we evaluated two hybrid peptides CM11 (WKLFKKILKVL-NH2) and CM15 (KWKLFKK IGAVLKVL-NH2) on five important pathogenic bacteria. These peptides are short cecropin-melittin hybrid peptides obtained through a sequence combination approach, which are highly effective to inhibit the growth of important pathogenic bacteria. The activity of these two cationic peptides (CM11 and CM15) in different concentrations (2-64 mg/L) was investigated against standard and clinical isolates of important hospital infection bacteria by measuring MIC, MBC, and bactericidal assay. These peptides demonstrated the same ranges of inhibitory values: The organisms in early 24 h were more susceptible to polycationic peptides (MIC: 8 mg/L and MBC 32 mg/L), but after 48 h the MIC and MBC remained constant for the CM11 peptide. Bactericidal assay showed that all bacteria strains did not have any growth in agar plates after 40 min. The result showed that these two peptides are more effective than other peptides.

World Journal of Microbiology and Biotechnology, 2014

Antimicrobial Agents and Chemotherapy, 1974

The in vitro activities of verdamicin and gentamicin were studied in parallel against 1,049 bacte... more The in vitro activities of verdamicin and gentamicin were studied in parallel against 1,049 bacterial isolates. Verdamicin demonstrated activity similar to that of gentamicin against members of the family Enterobacteriaceae and against Pseudomonas aeruginosa at 2 and 8 gg/ml, respectively. Proteus rettgeri and Providencia stuartii were notably more susceptible to verdamicin. The new aminoglycoside was also highly active against staphylococci but was not effective against group D streptococci. Verdamicin (SCH 15666), a new water-soluble aminoglycoside antibiotic produced by a new species of micromonospora, M. grisea NRRL 3800, is the dehydro analogue of gentamicin C2 (P.

ABSTRACT In recent years, the widespread use of conventional antibiotics has led to many microbia... more ABSTRACT In recent years, the widespread use of conventional antibiotics has led to many microbial pathogens becoming resistant to these antibiotics. Therefore, the development of novel and alternative therapeutic strategies for controlling and reducing the effects of these pathogens is urgently needed. Studies have shown that antimicrobial peptides (AMPs) and proteins are important members of the host defense system in eukaryotes. These peptides are potent agents with broad-spectrum activity against many Gram-positive and Gram-negative bacteria. In this review, we discuss the diversity, the broad spectrum of antimicrobial activity and related properties of AMPs that could be exploited for their application as potential drug candidates in therapeutic strategies against multiresistant pathogens.

With the growing microbial resistance to conventional antimicrobial agents, the development of no... more With the growing microbial resistance to conventional antimicrobial agents, the development of novel and alternative therapeutic strategies are vital. During recent years novel peptide antibiotics with broad spectrum activity against many Gram-positive and Gramnegative bacteria have been developed. In this study, antibacterial activity of CM11 peptide (WKLFKKILKVL-NH2), a short cecropin-melittin hybrid peptide, is evaluated against antibiotic-resistant strains of Klebsiella pneumoniae and Salmonella typhimurium as two important pathogenic bacteria. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal killing assay were utilized with different concentrations (2-128 mg/L) of peptide. To evaluate cytotoxic effect of peptide, viability of RAJI, Hela, SP2/0, CHO, LNCAP cell lines and primary murine macrophage cells were also investigated with MTT assay in different concentrations (3-24 and 0.5-16 mg/L, respectively). MICs of K. pneumoniae and S. typhimurium isolates were in range of 8-16 and 4-16 mg/L, respectively. In bactericidal killing assay no colonies were observed at 2X MIC for K. pneumoniae and S. typhimurium isolates after 80-90 min, respectively. Despite the fact that CM11 reveals no significant cytotoxicity on RAJI, Hela, SP2/0, and CHO cell lines beneath 6 mg/L at first 24 and 48 h, the viability of LNCAP cells are about 50 % at 3 mg/L, which indicates strong cytotoxicity of the peptide. In addition, macrophage toxicity by MTT assay showed that LD 50 of CM11 peptide is 12 lM (16 mg/L) after 48 h while in this concentration after 24 h macrophage viability was about 70 %.

"In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistanc... more "In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance to conventional antibiotics. Therefore, generation of new antibiotics to control and reduce the effects of these pathogens is urgently needed. Antimicrobial peptides and proteins are important members of the host defense system in eukaryotes. These peptides are potent, broad-spectrum antibiotics that demonstrate potential as novel and alternative therapeutic agents for the treatment of drug-resistant infections. Accordingly, we evaluated two hybrid peptides CM11 (WKLFKKILKVL-NH2) and CM15 (KWKLFKKIGAVLKVL-NH2) on five important pathogenic bacteria. These peptides are short cecropin–melittin hybrid peptides obtained through a sequence combination approach, which are highly effective to inhibit the growth of important pathogenic bacteria. The activity of these two cationic peptides (CM11 and CM15) in different concentrations (2–64 mg/L) was investigated against standard and clinical isolates of important hospital infection bacteria by measuring MIC, MBC, and bactericidal assay. These peptides
demonstrated the same ranges of inhibitory values: The organisms in early 24 h were more susceptible to polycationic peptides (MIC: 8 mg/L and MBC 32 mg/L), but after 48 h the MIC and MBC remained constant for the CM11 peptide. Bactericidal assay showed that all bacteria strains did not have any growth in agar plates after 40 min. The result showed that these two peptides are more effective than other peptides"

Thermophilic processes appear more stable, rapid and less expensive and facilitate reactant activ... more Thermophilic processes appear more stable, rapid and less expensive and facilitate reactant activity and product recovery. Amylases have a quarter of the world enzyme market and thermostable alpha-amylases possess extensive commercial applications. Since little work has been done on strain isolation, growth and enzyme yield optimization, the level of thermophilic enzyme production remains relatively low. Therefore, large scale exploitation of thermophiles requires further intensive and integrated work. The present study describes isolation of an a-amylase producing bacillus from soil. The isolated bacillus was identified and named as Bacillus licheniformis Shahed-07. The strain was cultured in liquid media to produce a-amylase. The enzyme production conditions of the newly isolated bacillus revealed that the maximum enzyme production after 26 h of cultivation at pH 7.0 and 50°C. 0.5% tryptophan in production medium enhanced the enzyme productivity to two fold whereas peptone and lysin at 0.5% level showed a strong repression. Crude a-amylase characterization revealed that optimum activity was at pH 7.5 and 70°C. The crude enzyme was stable for 24 h at pH range of
6-7 at 70°C. Enzyme activity increased with temperature within the range of 40-70°C. The Bacillus licheniformis Shahed-07 strain produced thermostable a-amylase with characteristics suitable for application in starch processing and food industries.