Wide distribution of carbapenem resistant Acinetobacter baumannii in burns patients in Iran
Frontiers in Microbiology
2015 | Volume 6
If:4.5
Zahra Farshadzadeh, Farhad B. Hashemi, Sara Rahimi, Babak Pourakbari, Davoud Esmaeili, Mohammad A. Haghighi, Ali Majidpour, Saeed Shojaa , Maryam Rahmani, Samira Gharesi, Masoud Aziemzadeh and Abbas Bahador
6 از 12
Antimicrobial resistance in carbapenemn on susceptible Acinetobacter baumannii (CNSAb) is a major public health concern globally. This study determined the antibiotic resistance and molecular epidemiology of CNSAb isolates from a referral burn center in Tehran , Iran . Sixty- nine CNSAb isolates were tested for susceptibility to antimicrobial agents using the E test methodology. Multiple locus variable number tandem repeat analysis (MLVA), Multilocus sequence ping (MLST) and multiplex PCR were performed .
PCR assay s tested f or ambler classes A, B , and D β -lactamases . Detect ion of ISAba1, characterization of integrons, and biofilm formation were investigated. Fifty-three (77%) isolates revealed XDR phenotypes. High prevalence of blaOXA−23-like (88%) and blaPER −1 (54%) were detected. ISAba1 was detected upstream of blaADC, blaOXA−23- like and blaOXA51 -like genes in, 97, 42, and 26% of isolates, respectively. Thirty-one (45%) isolates were assigned to international clone (IC) variants. MLVA identified 56 distinct types with six clusters and 53 singleton genotypes. Forty previously known MLST sequence types forming 5 clonal complexes were identified. The Class 1 integron (class 1 integrons) gene was identified in 84% of the isolates. The most prevalent (33%) cassette combination was aacA4-catB8-aadA1. The IC variants were predominant in the A. baumannii lineage with the ability to form strong biofilms. The XDR-CNSAb from burned patients in Iran is resistant to various antimicrobials, including tigecycline. This study shows wide genetic diversity in CNSAb. Integrating the new Iranian A. baumannii IC variants into the epidemiologic clonal and susceptibility profile databases can help effective global control measures against the XDR-CNSAb pandemic
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doi:10.3389/fmicb.2015.01146
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Application of Bioinformatics and Genetic Engineering for Designing Optimized Cloning and Overexpression of Neutrophil Activating Protein of Helicobacter pylori in Escherichia coli
مجله علمی پژوهشی دانشگاه علوم پزشکی زنجان
دوره 21 شماره 85 سال 92
علمی پزوهشی
نمایه شده در scopus
Haghighi MA, Mohabati Mobarez A, Salmanian AH, Zali MR, Moazzeni SM, Karkhane AA
1 از6
Background and Objective: As the main virulence factor of Helicobacter pylori, HP-NAP has an important role in immunoprotection against this pathogen. This antigen is a strong candidate as a part of multicomponent vaccine in the clinical trial against this bacterium. Due to NAP importance, it was used in this study as a template for optimization of heterologous genes with a low A-T content and low expression in E. coli.
Materials and Methods: A synthetic single gene that could reach the highest level of expression in the host was designed by using bioinformatics tools.
Results: A number of factors that influence gene expression level were changed for HP-NAP gene optimizing: the codon usage bias in E. coli was changed; the G+C content was upgraded from 38% to 45%; and the stem-loop structure was broken. These could result to prolong of the half-life of the mRNA and overexpression of recombinant of HP-NAP protein up to 800 mg per liter.
Conclusion: Applying of bioinformatics tools was appropriated to optimize of HP-NAP overexpression in E.coli. From our results, it appears that combination of In Silico and experimental approach is a logical approach for expression of heterologous genes in another host.
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In silico experiment with an antigen-toll-like receptor-5 agonist fusion construct for immunogenic application to Helicobacter pylori
Indian Journal of Human Genetics
2013 Volume 19 Issue 1
نمایه شده در Pub-med
Mohamad Ali Haghighi, Ashraf Mohabati Mobarez, Ali Hatef Salmanian, Mohamad Moazeni, Mohamad Reza Zali, Mehdi Sadeghi, Jafar Amani
1 از 7
BACKGROUNDS: Helicobacterpylori colonize the gastric mucosa of half of the world’s population. Although it is classifid as a defiitive type I carcinogen by World Health Organization, there is no effective vaccine against this bacterium. H. pylori evade the host immune response by
avoiding toll‑like detection, such as detection via toll‑like receptor‑5 (TLR‑5). Thus, a chimeric construct consisting of selected epitopes from virulence factors that is incorporated into a TLR‑5 ligand (Pseudomonas flgellin) could result in more potent innate and adaptive immune responses.
MATERIALS AND METHODS: Based on the histocompatibility antigens of BALB/c mice, in silico techniques were used to select several ragments from H. pylori virulence factors with a high density of B‑ and T‑cell epitopes. RESULTS: These segments consist of ytotoxin‑associated eneA (residue 162‑283), neutrophil activating protein (residue 30‑135) and outer inflmmatory protein A (residue 155‑268). The secondary and tertiary structure of the chimeric constructs and other bioinformatics analyses such as stability, solubility, and antigenicity were performed. The chimeric construct containing antigenic segments of H. pylori proteins
was fused with the D3 domain of Pseudomonas flgellin. This recombinant chimeric gene was optimized for expression in Escherichia coli. The in silico results showed that the conserved C‑ and N‑terminal domains of flgellin and the
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www.ijhg.com
DOI: 10.4103/0971-6866.112885
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Preparation of chitosan nanoparticles carrying recombinant helicobacter pylori neutrophil-activating protein
مجــلــــه دانـشـــگاه عــلـــوم پــزشــكــــي مــازنـــدران
volume 135,2014
علمی پزوهشی
نمایه شده در scopus
Neda Soleimani, Ashraf Mohabati-Mobarez, Fatemeh Atyabi, Zohair Hasan-Saraf, Mohammad-Ali Haghighi
5 از 5
Background and purpose: Breast cancer is one of the leading causes of death in women around the world with a very high degree of mortality and morbidity. Conventional treatments use cytotoxic drugs which have high
levels of side effects, affecting the patient’s quality of life. Therefore today’s pharmacology is looking into treatments with low side effects and maximum efficiency. The helicobacter pylori neutrophil-activating protein
(HP-NAP) is a virulence factor that attracts and activates neutrophils, and promotes their endothelial adhesion and the production of oxygen radicals and chemokines. HP-NAP is an immune modulator able to induce the expression of IL-12 and IL-23. Chitosan is biodegradable and biocompatible component. It is low toxicity effect, so apply in drug delivery targets. In this study, we evaluated the preparation of chitosan nanoparticles carrying recombinantHP-NAP helicobacter pylori.
Materials and methods: Chitosan nanoparticles were produce. The size and morphology of the nanoparticles were investigated. Recombinant HP-NAP helicobacter pylori were produce.
Results: SDS-PAGE analysis showed the expression of an approximately 20,000 Dalton protein. DLS confirm
size and zeta potential of the nanoparticle.
Conclusion: The complex has the potential to shift antigen-specific T-cell responses from a predominant Th2 to a polarized Th1 cytotoxic phenotype, characterized by high levels of interferon-γ and tumor necrosis factor-a production. HP-NAP may be a new tool for future therapeutic strategies aimed in cancer immunotherapy. Nanomaterials have been used to enable drug delivery with lower toxicity to healthy cells and enhanced drug delivery to tumor cells.
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Growth Rate and Biofilm Formation Ability of Clinical and Laboratory-Evolved Colistin-Resistant Strains of Acinetobacter baumannii
Frontiers in Microbiology
February 2018 | Volume 9
Open access
Q1
ششم از هفتم
Two different mechanisms of resistance to colistin in Acinetobacter baumannii have
been described. The first involves the total loss of lipopolysaccharide (LPS) due
to mutations in the lpxACD operon, which is involved in the lipid A biosynthesis
pathway. The second entails the addition of ethanolamine to the lipid A of the LPS
resulting from mutations in the PmrAB two-component system. To evaluate the impact
of colistin resistance-associated mutations on antimicrobial resistance and virulence
properties, four pairs of clinical and laboratory-evolved colistin-susceptible/colistinresistant (ColS/ColR) A. baumannii isolates were used. Antimicrobial susceptibility,
surface motility, in vitro and in vivo biofilm-forming capacity, in vitro and in vivo expression
levels of biofilm-associated genes, and in vitro growth rate were analyzed in these
strains. Growth rate, in vitro and in vivo biofilm formation ability, as well as expression
levels of biofilm-associated gene were reduced in ColR LPS-deficient isolate (the lpxD
mutant) when compared with its ColS partner, whereas there were not such differences
between LPS-modified isolates (the pmrB mutants) and their parental isolates. Mutation
in lpxD was accompanied by a greater reduction in minimum inhibitory concentrations
of azithromycin, vancomycin, and rifampin than mutation in pmrB. Besides, loss of LPS
was associated with a significant reduction in surface motility without any change in
expression of type IV pili. Collectively, colistin resistance through loss of LPS causes a
more considerable cost in biological features such as growth rate, motility, and biofilm
formation capacity relative to LPS modification. Therefore, ColR LPS-modified strains
are more likely to spread and transmit from one patient to another in hospital settings,
which results in more complex treatment and control.
دریافت فایل پیوست
www.frontiersin.org
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The Relationship Between Antibiotic Resistance Phenotypes and
Biofilm Formation Capacity in Clinical Isolates of Acinetobacter
baumannii
Jundishapur Journal of Microbiology
2018 July 18
Sara Rahimi, Zahra Farshadzadeh, Behrouz Taheri, Mohsen Mohammadi, Mohammad-Ali Haghighi, and Abbas Bahador
پنجم از ششم
Background: Understanding of the biological factors responsible for prevalence and persistence of Acinetobacter baumannii in hospital settings is critical to prevent and control the corresponding nosocomial infections.
Objectives: This study was conducted to investigate whether the biofilm-forming ability is associated with the emergence of different antibiotic resistance phenotypes [multidrug resistance (MDR)/extensively drug resistance (XDR) and non-MDR] of A. baumannii.
Methods: The capacitiesof biofilmformation in 80 clinicalA. baumanniistrains isolatedfromhospitalized burn patients inBushehr,
Iran, were assessed using the crystal violet staining.
Results: The statistical analysis of the relationship between biofilm-forming ability and antibiotic resistance phenotypes among all
clinical A. baumannii strains using one-way ANOVA test indicated that biofilm formation capacity of non-MDR A. baumannii isolates
was significantly higher than that of MDR and XDR ones (P < 0.001), suggesting an inverse relationship between biofilm formation
capacity and the acquisition of MDR/XDR phenotypes. Major international clonal types(ICI and ICII) also exhibited such a significant
relationship (P < 0.0001). However, the investigation of A. baumannii IC variants showed no significant relationship between these
phenotypes.
Conclusions: Given that non-MDR A. baumannii isolates in major IC types were observed to form a strong biofilm compared to
MDR/XDR ones, it seems that biofilm may play a key role in the persistence and survival of A. baumannii isolates with an inadequate
level of antibiotic resistance. Furthermore, the results showed that the relationship between biofilm and antibiotic resistance phenotypes might be affected by the IC types (major IC types or IC variants).
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PCR Identification of Escherichia coli Isolated
from Bushehr Coastal Water
Iran South Med J
علمی پژوهشی
چهارم از چهار
Background: Standard methods of identification have not been able to solve all issues concerning E. coli.
With the development of genomic studies, PCR appears promising to deal with the shortcomings. This study
aimed to utilize PCR with specific primers for lacZ, uidA, cyd, and lacY gene segments to identify
environmental E. coli isolates.
Materials and methods: PCR and the aforementioned four primers were used for molecular identification
of E. coli on purified genome DNA from 120 environmental E. coli isolates, standard strains of Shigella,
and Enterohaemorrhagic E. coli strain as controls. All environmental E. coli isolates were isolated from
Bushehr coastal areas and identified in a previous study by standard bacteriological methods and then
preserved in -70 C for further studies.
Results: The primers successfully showed their ability to identify the targets in environmental isolates and
standard strains. It is shown that the four PCR fragments related to lacZ, uidA, cyd, and lacY genes were
observed only for E. coli isolates and strains.
Conclusion: PCR method proved capable to distinguish E. coli from Shigella as the most phylogenetically
related genus and contrary to the classical methods, it could detect enterohaemorrhagic strains as
Escherichia coli.
دریافت فایل پیوست
http://ismj.bpums.ac.ir
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Presence of Shiga Toxin Gene in Clinical Isolates
of Shigella Species from the Past to Present in
Bushehr, Iran
Iran South Med J
2018
علمی پژوهشی
G. Noorabadi (MSc)1*, M. Siyavashi (MSc)1, K. Vahdat (MD)2, O. Gharibi (BS)3, M. Mahmudpour (MD)2, MA. Haghighi (PhD)2,4**
ششم از شش
Background: The Shiga cytotoxin (Stx) is involved in serious human intestinal diseases. Recently stx has
been found in non-S dysenteriae1 Shigella species. This study aimed to identify stx gene in clinical strains
of Shigella isolated from two shigellosis outbreaks in previous years in Bushehr, southwest of Iran.
Materials and Methods: Purified DNA of 143 Shigella isolates was used for PCR to detect stx and ipaH
genes. The number of PCR products in various Shigella species isolates was sequenced with the same
primers (evt) used to amplify this region.
Results: Fourteen (22.3%) out of 63 shigella isolates related to previous shigellosis outbreaks during 2002-2004
contained the PCR positive result with evt primers .The sequencing results indicated that the evt PCR product had
the most identity (97%) with Shigella dysentery shiga toxin subunit A. All clinical shigella strains isolated
during 2013-2015 yielded PCR negative results with primers stx and evt. PCR results revealed that ipaH was
present in all isolates. According to biochemical and species-specific antiserum tests, the stx gene harboring
isolates included 9 (14.3%) S. flexneri, 4 (6.4%) S. sonnei, and 1(1.6%) S. boydii.
Conclusion: The stx gene has already been distributed in different Shigella species of Bushehr region.
However, the absence of this gene in the clinical isolates of recent shigellosis outbreaks may be temporary.
Because stx gene increases the pathogenic potential of Shigella, it is necessary to monitor the prevalence of
the stx harboring Shigella species by molecular methods in the future.
دریافت فایل پیوست
http://ismj.bpums.ac.ir
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First Molecular Identification of Symbiotic Archaea in a Sponge Collected from the Persian Gulf, Iran
The Open Microbiology Journal
2018, Volume 12
Akram Najafi, Maryam Moradinasab, Mohammad Seyedabadi, Mohammad A. Haghighi and Iraj Nabipour
4 از 5 نفر
Abstract:
Background:
Marine sponges are associated with numerically vast and phylogenetically diverse microbial communities at different geographical
locations. However, little is known about the archaeal diversity of sponges in the Persian Gulf. The present study was aimed to
identify the symbiotic archaea with a sponge species gathered from the Persian Gulf, Iran.
Methods:
Sponge sample was collected from a depth of 3 m offshore Bushehr, Persian Gulf, Iran. Metagenomic DNA was extracted using a
hexadecyl trimethyl ammonium bromide (CTAB) method. The COI mtDNA marker was used for molecular taxonomy identification
of sponge sample. Also, symbiotic archaea were identified using the culture-independent analysis of the 16S rRNA gene and PCRcloning.
Results:
In this study, analysis of multilocus DNA marker and morphological characteristics revealed that the sponge species belonged to
Chondrilla australiensis isolate PG_BU4. PCR cloning and sequencing showed that all of the sequences of archaeal 16S rRNA gene
libraries clustered into the uncultured archaeal group.
Conclusion:
The present study is the first report of the presence of the genus of Chondrilla in the Persian Gulf. Traditional taxonomy methods,
when used along with molecular techniques, could play a significant role in the accurate taxonomy of sponges. Also, the uncultured
archaea may promise a potential source for bioactive compounds. Further functional studies are needed to explore the role of the
sponge-associated uncultured archaea as a part of the marine symbiosis.
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Identification of cholix toxin gene in Vibrio cholerae non-O1/non-O139
isolated from diarrhea patients in Bushehr, Iran
Identification of cholix toxin gene in Vibrio cholerae non-O1/non-O139 isolated from diarrhea patients in Bushehr, Iran Iranian journal of Microbiology
Volume 12 Number 4 (August 2020)
Marziyeh Gholizadeh Tangestani1,2, Jafar Alinezhad1,2, Abdolmohammad Khajeian2, Somayyeh Gharibi3, Mohammad Ali Haghighi1,2*
5 از 5 Correspondin author
ABSTRACT
Background and Objectives: Cholixin (cholix toxin) is a novel exotoxin in Vibrio cholerae identified as an elongation
factor II specific ADP-ribosyltransferase which inhibits protein synthesis in the eukaryotic cell. Previous researches have
suggested that cholixin probably is an important virulence factor in non-O1/non-O139 V. cholerae (NAG) serotypes that
could be related to extra-intestinal rather than intestinal infections. This study was aimed to investigate the frequency and
genetic diversity of colixin gene (chxA) in clinical V. cholerae NAG isolates.
Materials and Methods: The presence of chxA gene in 44 clinical V. cholerae NAG isolates were screened using PCR
through specific primers designed for the receptor-binding domain (RBD) of chxA gene. The five PCR products of chxA gene
were sequenced.
Results: This study showed that chxA gene presented in 19 V. cholerae NAG isolates. The sequences analysis of 5 out of 19
the partial chxA genes amplicon showed that 4 of them belonged to chxA I and the other one belonged to chxA II subtypes.
Two distinct clusters were revealed for these isolates by phylogenic analysis, too.
Conclusion: The chxA gene contained high frequency among V. cholerae NAG isolates in Bushehr, Iran. The polymorphism
study on RBD of cholixin gene is suggested as an appropriate method for phylogenic characterization of the various chxA
gene subtypes.
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Engineering of Cytolethal Distending Toxin B by Its Reducing
Immunogenicity and Maintaining Stability as a New Drug
Candidate for Tumor Therapy; an In Silico Stud
Toxins
Engineering of Cytolethal Distending
Toxin
7 از 9
Abstract: The cytolethal distending toxin (CDT), Haemophilus ducreyi, is one of the bacterial toxins
that have recently been considered for targeted therapies, especially in cancer therapies. CDT is an
A‐B2 exotoxin. Its catalytic subunit (CdtB) is capable of inducing DNA double strand breaks, cell
cycle arrest and apoptosis in host eukaryotic cells. The sequence alignment indicates that the CdtB
is structurally homologyr to phosphatases and deoxyribonucleases I (DNase I). Recently, it has been
found that CdtB toxicity is mainly related to its nuclease activity. The immunogenicity of CDT can
reduce its effectiveness in targeted therapies. However, the toxin can be very useful if its
immunogenicity is significantly reduced. Detecting hotspot ectopic residues by computational
servers and then mutating them to eliminate B‐cell epitopes is a promising approach to reduce the
immunogenicity of foreign protein‐based therapeutics. By the mentioned method, in this study, we
try to reduce the immunogenicity of the CdtB‐ protein sequence. This study initially screened
residue of the CdtB is B‐cell epitopes both linearly and conformationally. By overlapping the B‐cell
epitopes with the excluded conserve residues, and active and enzymatic sites, four residues were
allowed to be mutated. There were two mutein options that show reduced antigenicity probability.
Option one was N19F, G74I, and S161F with a VaxiJen score of 0.45 and the immune epitope
database (IEDB) score of 1.80, and option two was N19F, G74I, and S161W with a VaxiJen score of
0.45 and IEDB score of 1.88. The 3D structure of the proposed sequences was evaluated and refined.
The structural stability of native and mutant proteins was accessed through molecular dynamic
simulation. The results showed that the mutations in the mutants caused no considerable changes
in their structural stability. However, mutant 1 reveals more thermodynamic stability during the
simulation. The applied approaches in this study can be used as rough guidelines for finding hot
spot immunogen regions in the therapeutic proteins. Our results provide a new version of CdtB
that, due to reduced immunogenicity and increased stability, can be used in toxin‐based drugs such
as immunotoxins
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Phylogenetic study, distribution of virulence genes and antibiotic resistance profiles of Escherichia coli isolated from Bushehr coastal water
Gene Reports
26 2022
Zahra Rahimi a, Yalda Malekzadegan b, Abbas Bahador c, Masoud Azimzadeh a, Mohammad Ali Haghighi
5 از 5 Correspondin author
Objective: Microbial pollution of coastal water continues to rise human health concerns, following the consecutive
population growth, especially in urban communities along beaches. Bushehr coastal water was evaluated to
understand the intensity of human health risks. In this study, E. coli strains isolated from Bushehr coastal water
samples were characterized for their pathotypes, phylogenetic groups, and antibiotic resistance pattern.
Methods: A total of 120 E. coli environmental isolates obtained from coastal water samples were analyzed for
susceptibility to 22 different antibiotics by using the agar disc diffusion method. The polymerase chain reaction
was performed to detect the distribution of virulence-associated genes and phylogenetic groups among selected
isolates.
Results: Among the isolates, the prevalence of multidrug resistance (MDR) and non- multidrug resistance (NonMDR) phenotypes were 60% and 34.17%, respectively. Moreover, the rate of resistance was highest to cotrimoxazole (24.17%) followed by ampicillin (22.50%) and nalidixic acid (18.33%). While the rate of resistance
was lowest to cefepime, imipenem, and meropenem at the same rate of 0.83%. The pathogenic isolates contrived
10% of the population study and included EPEC, EIEC, and ETEC.
The Clermont phylogenic analysis revealed phylogroup B1 (20.00%) was most prevalence followed A (19.17%),
C (17.50%), E (13.33%), Clade I/II (3.33%), and B2 (2.50%). Moreover, 24.17% of isolates were not classified in
the defined Clermont phylogroups.
Conclusions: Any recreational use or food exploitation of the polluted areas of Bushehr beaches may cause
transmission of multidrug-resistant and pathogenic E. coli strains to individuals and threaten human health.
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