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Simultaneous lactic acidification and coagulation by using recombinant Lactococcus lactis strain

Raftari M, Ghafourian S, Abu Bakar F

J Appl Microbiol, 2017 Apr;122(4):1009-1019.
PMID: 28028882 DOI: 10.1111/jam.13388

AIMS: This study was an attempt to create a novel milk clotting procedure using a recombinant bacterium capable of milk coagulation.
METHODS AND RESULTS: The Rhizomucor pusillus proteinase (RPP) gene was sub-cloned into a pALF expression vector. The recombinant pALF-RPP vector was then electro-transferred into Lactococcus lactis. Finally, the milk coagulation ability of recombinant L. lactis carrying a RPP gene was evaluated. Nucleotide sequencing of DNA insertion from the clone revealed that the RPP activity corresponded to an open reading frame consisting of 1218 bp coding for a 43·45 kDa RPP protein. The RPP protein assay results indicated that the highest RPP enzyme expression with 870 Soxhlet units (SU) per ml and 7914 SU/OD were obtained for cultures which were incubated at pH 5·5 and 30°C. Interestingly, milk coagulation was observed after 205 min of inoculating milk with recombinant L. lactis carrying the RPP gene.
CONCLUSION: The recombinant L. lactis carrying RPP gene has the ability to function as a starter culture for acidifying and subsequently coagulating milk by producing RPP as a milk coagulant agent.
SIGNIFICANCE AND IMPACT OF THE STUDY: Creating a recombinant starter culture bacterium that is able to coagulate milk. It is significant because the recombinant L. lactis has the ability to work as a starter culture and milk coagulation agent.
Fulltext Is the mazEF toxin-antitoxin system responsible for vancomycin resistance in clinical isolates of Enterococcus faecalis?

Sadeghifard N, Soheili S, Sekawi Z, Ghafourian S

GMS Hyg Infect Control, 2014;9(1):Doc05.
PMID: 24653969 DOI: 10.3205/dgkh000225

The current study was conducted to investigate the relationship between vancomycin-resistant Enterococcus faecalis (VRE) and the presence of mazEF toxin-antitoxin (TA) system, which may be useful as target for novel antimicrobial therapy concepts. The susceptibility of E. faecalis was determined by MIC, and the presence of the mazEF TA system was evaluated by PCR. Among 200 E. faecalis isolates 39.5% showed resistance to vancomycin (VRE), while 60.5% were susceptible strains (VSE). The mazEF TA system was positive in all VRE isolates (100%), but less prevalent (38/121, 31.4%) among the 121 VSE strains. In conclusion, our study demonstrated a positive relationship between the presence of vancomycin resistance and mazEF TA system. This observation may introduce therapeutic options against a novel antimicrobial target in enterococci.
Ex Vivo Evaluation of Thymus daenensis as an Antioxidant and Antibacterial Medicinal Herb

Saidi M, Sadeghifard N, Kazemian H, Sekawi Z, Badakhsh B, Friadian S, et al.

Drug Res (Stuttg), 2016 Sep 14.
PMID: 27626607

Herbal medicines are defined as traditionally used natural products. The current study in an attempt try to investigate the antibacterial activity on extended spectrum beta-lactamases (ESBL), methalo beta-lactamases (MBL) producing gram negative bacteria and methicillin resistant Staphylococcus aureus (MRSA) and subsequently, to determine the antioxidant activity of Thymus daenensis. For this reasons, firstly cytotoxicity of T. daenensis was determined by MTT assay. Then, essential oil was subjected for antibacterial and antioxidant activity. Our results demonstrated that 15 mg/ml concentration of T. daenensis inhibited both P. aeruginosa producing MBL and E.coli producing ESBL, while this value was 25 mg/ml concentration for MRSA inhibition. The association between phenolic compound and antioxidant activity was found for the ABTS(•+) method (43.52%) in the lowest level, while, for FRAD and DPPH(•) methods the opposite story occurred (70.5% correlation for DPPH(•) and 50.9% for FRAD). Our findings suggested that T. daenensis has a potential herbal medicine that should be considered as an antibacterial and antioxidant with very low toxicity.
Extended Spectrum Beta-lactamases: Definition, Classification and Epidemiology

Ghafourian S, Sadeghifard N, Soheili S, Sekawi Z

Curr Issues Mol Biol, 2015;17:11-21.
PMID: 24821872

Extended spectrum beta-lactamases (ESBLs) are defined as enzymes produced by certain bacteria that are able to hydrolyze extended spectrum cephalosporin. They are therefore effective against beta-lactam antibiotics such as ceftazidime, ceftriaxone, cefotaxime and oxyimino-monobactam. The objective of the current review is to provide a better understanding of ESBL and the epidemiology of ESBL producing organisms which are among those responsible for antibiotic resistant strains. Globally, ESBLs are considered to be problematic, particularly in hospitalized patients. There is an increasing frequency of ESBL in different parts of the world. The high risk patients are those contaminated with ESBL producer strains as it renders treatment to be ineffective in these patients. Thus, there an immediate needs to identify EBSL and formulate strategic policy initiatives to reduce their prevalence.
Toxin-antitoxin Systems: Classification, Biological Function and Application in Biotechnology

Ghafourian S, Raftari M, Sadeghifard N, Sekawi Z

Curr Issues Mol Biol, 2014;16:9-14.
PMID: 23652423

The toxin-antitoxin (TA) systems are systems in which an unstable antitoxin inhibits a stable toxin. This review aims to introduce the TA system and its biological application in bacteria. For this purpose, first we introduce a new classification for the TA systems based on how the antitoxin can neutralize the toxin, we then describe the functions of TA systems and finally review the application of these systems in biotechnology.
Metabolic engineering of Lactococcus lactis influence of the overproduction of lipase enzyme

Raftari M, Ghafourian S, Bakar FA

J Dairy Res, 2013 Nov;80(4):490-5.
PMID: 24063299 DOI: 10.1017/S0022029913000435

The dairy industry uses lipase extensively for hydrolysis of milk fat. Lipase is used in the modification of the fatty acid chain length, to enhance the flavours of various chesses. Therefore finding the unlimited source of lipase is a concern of dairy industry. Due to the importance of lipase, this study was an attempt to express the lipase from Burkholderia cepacia in Lactococcus lactis. To achieve this, a gene associated with lipase transport was amplified and subcloned in inducible pNZ8148 vector, and subsequently transformed into Lc. lactis NZ9000. The enzyme assay as well as SDS-PAGE and western blotting were carried out to analysis the recombinant lipase expression. Nucleotide sequencing of the DNA insert from the clone revealed that the lipase activity corresponded to an open reading frame consisting of 1092 bp coding for a 37·5-kDa size protein. Blue colour colonies on nile blue sulphate agar and sharp band on 37·5-kD size on SDS-PAGE and western blotting results confirm the successful expression of lipase by Lc. lactis. The protein assay also showed high expression, approximately 152·2 μg/ml.h, of lipase by recombinant Lc. lactis. The results indicate that Lc. lactis has high potential to overproduce the recombinant lipase which can be used commercially for industrially purposes.
mazE Antitoxin of Toxin Antitoxin System and fbpA as Reliable Targets to Eradication of Neisseria meningitidis

Maleki A, Ghafourian S, Pakzad I, Badakhsh B, Sadeghifard N

Curr Pharm Des, 2018;24(11):1204-1210.
PMID: 29237374 DOI: 10.2174/1381612824666171213094730

BACKGROUND: Neisseria meningitidis is considered as a dangerous pathogen threatening human health. Nowadays, the new drug target is focused. Toxin antitoxin (TA) system is recently identified as an antimicrobial drug target. Also, in N. meningitidis, iron-uptake system could be an interesting target for drug discovery.
METHODS: In this study, fbpA and mazE genes were chosen as new antimicrobial targets and treated with antisense peptide nucleic acid (PNA). Firstly, they were evaluated by bioinformatics and then analyzed by experimental procedures. Secondly, the functionality was evaluated by stress conditions.
RESULTS: Our results interestingly demonstrated that when fbpA and mazE loci of N. meningitidis were targeted by antisense PNA, 8 µM concentration of fbpA-PNA as well as 30 µM concentration of mazE-PNA inhibited the growth of N. meningitides and were found to be bacteriostatic, whereas 10 μM concentration of fbpA-PNA showed bacteriocidal activity.
CONCLUSION: Our findings demonstrated the bactriocidal activity of fbpA-PNA and bacteriostatic activity of mazEPNA. Therefore, mazE and fbpA genes should be potent antimicrobial targets but further analysis including in vivo analysis should be performed.
Vitiligo: symptoms, pathogenesis and treatment

Ghafourian A, Ghafourian S, Sadeghifard N, Mohebi R, Shokoohini Y, Nezamoleslami S, et al.

Int J Immunopathol Pharmacol, 2015 1 13;27(4):485-9.
PMID: 25572727

Vitiligo is an acquired cutaneous disorder of pigmentation, with an incidence of 0.5% to 2% worldwide. There are three major hypotheses for the pathogenesis of vitiligo that are not exclusive of each other: biochemical/cytotoxic, neural and autoimmune. Recent data provide strong evidence supporting an autoimmune pathogenesis of vitiligo. As vitiligo can have a major effect on quality of life, treatment can be considered and should preferably begin early when then disease is active. Current treatment modalities are directed towards stopping progression of the disease and achieving repigmentation. Therapies include corticosteroids, topical immunomodulators, photo(chemo)therapy, surgery, combination therapies and depigmentation of normally pigmented skin. It seems that traditional Chinese medicine could be more effective than the current treatment for vitligo.
Fulltext Wide distribution of virulence genes among Enterococcus faecium and Enterococcus faecalis clinical isolates

Soheili S, Ghafourian S, Sekawi Z, Neela V, Sadeghifard N, Ramli R, et al.

ScientificWorldJournal, 2014;2014:623174.
PMID: 25147855 DOI: 10.1155/2014/623174

Enterococcus, a Gram-positive facultative anaerobic cocci belonging to the lactic acid bacteria of the phylum Firmicutes, is known to be able to resist a wide range of hostile conditions such as different pH levels, high concentration of NaCl (6.5%), and the extended temperatures between 5(°)C and 65(°)C. Despite being the third most common nosocomial pathogen, our understanding on its virulence factors is still poorly understood. The current study was aimed to determine the prevalence of different virulence genes in Enterococcus faecalis and Enterococcus faecium. For this purpose, 79 clinical isolates of Malaysian enterococci were evaluated for the presence of virulence genes. pilB, fms8, efaAfm, and sgrA genes are prevalent in all clinical isolates. In conclusion, the pathogenicity of E. faecalis and E. faecium could be associated with different virulence factors and these genes are widely distributed among the enterococcal species.
Fulltext Epidemiological alteration in pathogens found in ground meat in Iran: unexpected predominance of vancomycin-resistant Enterococcus faecalis

Sadeghifard N, Kazemian H, Mohebi R, Sekawi Z, Khosravi A, Valizadeh N, et al.

GMS Hyg Infect Control, 2015;10:Doc12.
PMID: 26213680 DOI: 10.3205/dgkh000255

Colonization of the human and animal intestinal tract with potential pathogenic bacteria is correlated with the risk of contamination of food products. The current study analyzed the prevalence of Enterococcus faecalis and Escherichia coli O157H7 in ground meat in Ilam, Iran. Both index organisms were identified following standard food microbiological methods. For E. faecalis, the susceptibility to vancomycin was tested, and PCR was used to check for the vanA gene. E. faecalis was present in all 24 ground meat samples, with no E. coli O157H7 detected in samples. The analysis showed the presence of the vanA gene in 5/24 vancomycin resistant enterococci. In conclusion, this study for the first time demonstrates the presence of vancomycin-resistant enterococci in ground meat in Iran. This observation warrants further epidemiologic investigation and should be followed up in the future.
Berberis vulgaris fruit crude extract as a novel anti-leukaemic agent

Saedi TA, Ghafourian S, Jafarlou M, Sabariah MN, Ismail P, Eusni RM, et al.

J Biol Regul Homeost Agents, 2015 Apr-Jun;29(2):395-9.
PMID: 26122228

Tumor protein p53 encoded by the TP53 gene in humans is known as a cancer biomarker in patients diagnosed with cancer, and it plays an essential role in apoptosis, genomic stability, and inhibition of angiogenesis. Cancer therapies with common chemotherapy methods are effective, as known, but have some side effects. Berberis vulgaris is traditionally administrated as a cancer drug. The current research aims to evaluate p53 as a biomarker in WEHI-3 cell line and to demonstrate the Berberis vulgaris fruit crude extract (BVFCE) as a new anticancer drug. For this purpose, we evaluated the effect of BVFCE in different concentrations against WEHI-3cell line in vitro and determined the quantitative level of p53 gene in the treated WEHI-3 cells. The results demonstrated that even at only 1 mg/ml concentration of Berberis vulgaris crude extract, there was a low level of p53 biomarker expression on WEHI-3 cells in comparison with doxorubicin. Therefore, the current study suggests BVFCE as a reliable anti-leukaemic drug and candidate for anticancer therapy. However, further investigation need be carried out to confirm its efficiency in vivo.
The Role of Peganum harmala Ethanolic Extract and Type II Toxin Antitoxin System in Biofilm Formation

Valizadeh N, Valian F, Sadeghifard N, Karami S, Pakzad I, Kazemian H, et al.

Drug Res (Stuttg), 2017 Jul;67(7):385-387.
PMID: 28320039 DOI: 10.1055/s-0043-102060

Toxin antitoxin system is a regulatory system that antitoxin inhibits the toxin. We aimed to determine the role of TA loci in biofilm formation in K. pneumoniae clinical and environmental isolates; also inhibition of biofilm formation by Peganum harmala. So, 40 K. pneumoniae clinical and environmental isolates were subjected for PCR to determine the frequency of mazEF, relEB, and mqsRA TA loci. Biofilm formation assay subjected for all isolates. Then, P. harmala was tested against positive biofilm formation strains. Our results demonstrated that relBE TA loci were dominant TA loci; whereas mqsRA TA loci were negative in all isolates. The most environmental isolates showed weak and no biofilm formation while strong and moderate biofilm formation observed in clinical isolates. Biofilm formations by K. pneumoniae in 9 ug/ml concentration were inhibited by P. harmala. In vivo study suggested to be performed to introduce Peganum harmala as anti-biofilm formation in K. pneumoniae.
The mazEF toxin-antitoxin system as a novel antibacterial target in Acinetobacter baumannii

Ghafourian S, Good L, Sekawi Z, Hamat RA, Soheili S, Sadeghifard N, et al.

Mem Inst Oswaldo Cruz, 2014 Jul;109(4):502-5.
PMID: 25004148

Although analysis of toxin-antitoxin (TA) systems can be instructive, to date, there is no information on the prevalence and identity of TA systems based on a large panel of Acinetobacter baumannii clinical isolates. The aim of the current study was to screen for functional TA systems among clinical isolates of A. baumannii and to identify the systems' locations. For this purpose, we screened 85 A. baumannii isolates collected from different clinical sources for the presence of the mazEF, relBE and higBA TA genes. The results revealed that the genes coding for the mazEF TA system were commonly present in all clinical isolates of A. baumannii. Reverse transcriptase-polymerase chain reaction analysis showed that transcripts were produced in the clinical isolates. Our findings showed that TA genes are prevalent, harboured by chromosomes and transcribed within A. baumannii. Hence, activation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium.
Fulltext The Prevalence of ESBLs Producing Klebsiella pneumoniae Isolates in Some Major Hospitals, Iran

Ghafourian S, Bin Sekawi Z, Sadeghifard N, Mohebi R, Kumari Neela V, Maleki A, et al.

Open Microbiol J, 2011;5:91-5.
PMID: 21915229 DOI: 10.2174/1874285801105010091

Aims of this study were to investigate on antibiotic resistance and molecular epidemiology of K.pneumoniae producing ESBLs isolates of respiratory tract infections in some major hospitals in Iran. K.pneumonaie were obtained of patients with RTI. K. pneumoniae producing ESBLs detected by screening, confirming and PCR methods. During the 12-month period, a total of one hundred and thirteen of K.pneumoniae were found from RTI in three cities in different region of Iran which Sixty seven strains (59.2%) were ESBLs producer. In Ilam hospitals, seventeen strains (43.6%), in Milad hospital, thirty-seven strains (74%) and in Emam Reza hospital, thirteen strains (54.2%) were ESBLs producer. The findings showed that among sixty-seven K.pneumoniae producing ESBLs, Sixty-three strains (94%) were positive for blaSHV, eleven strains (16.4%) contained blaTEM and sixteen strains (23.9%) harbored blaCTX-M. Imipenem was found as an effectiveness antibiotic. In the current study, Majority of the ESBLs production had occurred in Milad hospital in Tehran (74%). In conclusion, spreading ESBL-producing strains is a concern, as it causes limitations to the antimicrobial agents for optimal treatment of patients.
Fulltext The mazEF toxin-antitoxin system as an attractive target in clinical isolates of Enterococcus faecium and Enterococcus faecalis

Soheili S, Ghafourian S, Sekawi Z, Neela VK, Sadeghifard N, Taherikalani M, et al.

Drug Des Devel Ther, 2015;9:2553-61.
PMID: 26005332 DOI: 10.2147/DDDT.S77263

The toxin-antitoxin (TA) system is a regulatory system where two sets of genes encode the toxin and its corresponding antitoxin. In this study, the prevalence of TA systems in independently isolated clinical isolates of Enterococcus faecium and Enterococcus faecalis was determined, the dominant TA system was identified, different virulence genes in E. faecium and E. faecalis were surveyed, the level of expression of the virulence and TA genes in normal and stress conditions was determined, and finally their associations with the TA genes were defined. Remarkably, the analysis demonstrated higBA and mazEF in all clinical isolates, and their locations were on chromosomes and plasmids, respectively. On the other hand, a quantitative analysis of TA and virulence genes revealed that the expression level in both genes is different under normal and stress conditions. The results obtained by anti-mazF peptide nucleic acids demonstrated that the expression level of virulence genes had decreased. These findings demonstrate an association between TA systems and virulence factors. The mazEF on the plasmids and the higBA TA genes on the chromosomes of all E. faecium and E. faecalis strains were dominant. Additionally, there was a decrease in the expression of virulence genes in the presence of anti-mazF peptide nucleic acids. Therefore, it is suggested that mazEF TA systems are potent and sensitive targets in all E. faecium and E. faecalis strains.

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