جستجوی مقالات مرتبط با کلیدواژه «  -توکسین » در نشریات گروه « پزشکی »

A surprisingly large number of sea snail species are venomous. Cone snail venoms are produced in a lengthy tubular duct from a complex venom gland and form a cocktail of many toxins, particularly conotoxins which have high potency and specificity for their target specific receptors. They inhibit various channels, neuromuscular receptors or hormones of the victim, and interfere in the transmitted signals of the prey, or dissuade predators. Cone snails have an amazing ability to quickly convert between two different types of defense-evoked and predation-evoked venoms in response to defensive or predatory stimuli. Various conotoxins and conopeptides such as α-conotoxins, σ-conotoxins, ω-conotoxins, μ-conotoxins, ψ-conotoxins, τ-conotoxins, δ-conotoxins, κ-conotoxins and conkunitzins, conantokins, contryphans, Ac1 conotoxins, conoinsulins, granulin-like conotoxins from conoides; augerpeptides derived from the venom peptide family Terebridae; turripeptides from the venom peptide family Turridae; crassipeptides venom peptides from Crassispirids; clathurellipeptides from venomous micro-conoides Clathurellidae, and other toxins such as RFamide peptides and endogenous neuropeptide-like peptides such as conopressins, as well as contulakins have been found in cone snail venoms, which have demonstrated remarkable biological and pharmacological functions. Given the approval of some conotoxins, such as the analgesic medication ziconitide (Prialt®) in clinical trials as well as their biomedical potential, current research has focused on these toxins. The use of integrated venomics approaches has dramatically accelerated the detection of conotoxin sequences. It is anticipated that a better understanding and identification of conotoxins and other toxins derived from other sea snails will lead to their use for the treatment of diseases to which humans have succumbed.

 Sponges produce a wide range of toxins and secondary metabolites. The deadly poisons of some of them contain the strongest toxins known in nature and complex mixtures of bioactive compounds with different chemical structures. One of the aims of this systematic review study is to study the toxinology of sea sponges as well as toxins and bioactive compounds and their functional mechanisms.

To find studies on the toxicology of sea sponges and their bioactive compounds, in April 2021, the keywords of "toxinology, toxin, secondary metabolite, alkaloid, peptide, terpene, aromatic, steroid and lactone" along with the word "sponge" or "Porifra" were searched through the Google Scholar and Pubmed databases, from 2017 to 2021. After initial reviews based on the purpose of the study, 184 out of 211 articles were selected. The search for “Porifra” and the abovementioned compounds did not yield any results. Since the limited number of studies on sponge toxins were found in the initial search, the keywords "sponge and toxin" were re-searched between 1980 and 2021 in the Pubmed database, Scifinder (database of chemical compounds) and the Marin Lit Database (marine natural compounds research), and after omitting the duplicate articles, a total of 27 other related articles were selected and reviewed along with other selected articles.

Some toxins and main compounds isolated from different sea sponges, including different chemical groups such as okadaic acid; terpene derivatives such as agelasine, oxofasciospongia, dysivillosins, and hipposponlachnins; peptides such as polytheonamides, soritesidines, and scleritodermins; many different alkaloid compounds include guanidine alkaloids such as monanchocidins, mycalins, crambescidins, unguiculins, netamines, zarzissine, hachijodines; Acridine alkaloids such as amphimedines; bromine and bromotyrosine alkaloids such as aplysinins; benzonaphthryidine derivatives such as aaptamines; imidazole derivatives such as nonamidines; indole derivatives such as fascaplysins, dragmacidins and topsentins; piperidine alkaloids such as saraines, madangamines, haliclonacyclamines, and arenosclerins; pyrimidine alkaloids such as lanesoic acid,  hyrtinadine, and variolins; pyridine alkaloids such as amphimedosides and pyrinadines; pyrrole and pyrroloiminoquinoline alkaloids such as makaluvamine, discorhabdins, tsitsikammamines and batzellines; pyrrole compounds such as hymenialdisines as well as quinoline alkaloids such as araguspongines, renieramycins, renierol and lihouidine; steroid compounds such as plakinamines; lactones such as thorectandrols, palauolol, koshikamides, petrosaspongias, latrunculins and other compounds with unique structure and biological effects.

There is a great variety of toxins and bioactive molecules in different species of sea sponges that offer a wide range of amazing pharmacological and biological activities.

Although the widespread distribution of venomous marine worms around the world, the structural and toxinologcal studies of their toxins are still limited.This study was aimed to evaluate the toxicity of poisonous marine worms. Touching the cilium of Chloeia flava and Sipuncula marine worms cause painful inflammation of the skin. Many species of nemertines prey their victims by a flexible proboscis and dense mucus on the surface of the skin. They have recently been classified into three groups of the Palaeonmertea, Pilidiophora, and Hoplonemertea. Their toxins comprise the three main groups of peptides, pyridine alkaloids, and tetradotoxin and their derivatives. The nicotinoide amphiporine compound, anabaseine and its derivatives, Nemertelline, and anabasine are as alkaloid toxins. They are selectively stimulated the  nicotinic receptors, in particular the type of α-7 receptors. Nemerteans are produced a variety of peptide toxins.The hemolytic activity is the most prominent activity of the cerebratulus toxins A-I to A-IV. Cytotoxin A-III, by forming tetrameric forms in the membranes of many different cells, and creating large pores, makes them very permeable. The toxin inhibits the protein kinase C and the selective cationic sodium and calcium channels of the voltage-gate in the nervous and cardiovascular systems at low lytic concentrations. From four main proteins "Cerebratulus toxins- B-II to B-IV", the toxin B-II performed to be the most toxic compound.The assessment of the Lineus extract showed that they are actually more toxic than Cerebratulus extracts. The neurotoxins α- and β-nemertides, respectively, belong to the family of three and six kilodaltons. The nemertide α-1 is highly potent toxin against the VGSC. Dose-dependent injections have caused permanent paralysis to death. Many toxin genes have been predicted or discovered in the genomes and transcriptoms of nemerteans. The most prominent of the toxin genes were the Plancitoxin-1 sequence, Stichodactyla toxin peptide (Shk toxin), Se-Cephalotoxin, β pore-forming toxin aerolysin, and several neurotoxin-related sequences, such as delta-actitoxin-Amc1a, Perivitellin-2, Mu-theraphotoxin Hhn2a 4 and turripeptide Gsg9.2, different α-, β-nemertides (B-neurotoxins analogs), and Parborlysin. Most likely, the Parborlysins belong to the same family of cytotoxins AI-AIV. Study on these marine organism toxins can provide useful probes for examining receptors, ion channels, and even innate immunity mechanisms against infectious viruses, parasites, and other microbes.

The importance of freshwater resources and water infrastructure for the health of human communities has made them one of the main targets of terrorist attacks. Currently, 9 types of biological toxins are considered to be potentially important factors in bioterrorism to contaminate drinking water resources. These toxins include botulinum toxin, T-2 mycotoxin, ricin, aflatoxin, saxitoxin, anatoxin A, tetrodotoxin, staphylococcal enterotoxins, and microcystin. There have been several reported terrorist attacks in the world using contaminated drinking water by microbial pathogens. Unlike most terrorist factors, it is very difficult to detect threats to water resources, and because such attacks are characterized only by the spread of contaminated water and the loss of many lives in an outbreak or epidemic, it is important to identify and deal with quickly. In addition to permanent control and elimination of the possible vulnerability of reservoirs and drinking water facilities in usual conditions, in order to quickly and efficiently deal with these threats, especially in crisis situations, most countries are equipped with diagnostic laboratories, monitoring systems and advanced monitoring networks. It seems vital to set up a specialized reference laboratory for controlling and monitoring drinking water in the field of passive defense. In addition to general and traditional tests, this laboratory must have specialized departments for monitoring, tracking and rapid detection of microbial pathogens contaminating drinking water, as well as biological toxins in this area using molecular, immunological methods, biosensors and nanosensors.

  Multiple Sclerosis is a vascular disease in the central nervous system. There is evidence that Clostridium perfringens epsilon toxin causes damage to the myelin of the neuronal cells by increasing the permeability of the blood-brain barrier, and therefore contributes to the disease. Therefore, the aim of this study was the molecular identification of C. perfringens Epsilon toxin in samples isolated from multiple sclerosis patients using multiplex-PCR.

In this descriptive cross-sectional study, 60 stool samples of patients with multiple sclerosis and 60 specimens of healthy individuals were studied. e-toxin producing C. perfringens infection was examined by the M-PCR method after genomic DNA extraction.

  of 60 fecal specimens obtained from patients with multiple sclerosis, 11 (18.3%) and 2 (3.3%) samples were positive for 16S rRNA and ε-toxin-encoding gene, respectively.

The results of this study showed that the prevalence of C. perfringens toxigenic strains in MS patients are higher than in the control group, which can indicate the association between the presence of this toxin and MS disease.

One of the main problems in many diseases is pain which has social, psychological and physical symptoms on patients. Due to the side effects of analgesic drugs, new effective compounds to reduce pain are needed. Ionic channels, acetylcholine and gamma aminobutyric acid receptors and molecules such as nitric oxide are involved in pain paths. Animal venoms contain small molecules with various pharmaceutical and analgesic properties. Anti-pain peptides have isolated from the scorpions, snakes, spiders and cone snails that block channels and molecules involved in pain pathways. This article has been reviewed animal venoms and their use in pain treatment.

Secreted toxins of the burn wounds caused by Pseudomonas aeruginosa play an important role in spreading infection. The antibiotic resistance pattern may have an effect on the increased toxicity of this bacterium. Therefore, the aim of this study was to determine the relationship between the presence of P. aeruginosa toxins isolated from burn wounds and the antibiotic resistance pattern. In this cross sectional-descriptive study, P. aeruginosa isolates were first isolated from the burn wound samples by using biochemical tests. The next step dealt with the investigation of antibiotic resistance pattern based on CLSI (Clinical and Laboratory Standards Institute). The process of identifying the genes responsible for producing toxin was performed by polymerase chain reaction method. Data analysis was performed in SPSS (version 16) using the Chi-square test. Out of 250 strains isolated from burn wounds, 63 isolates (25.2%) were obtained from P. aeruginosa. With regard to resistance, the obtained results revealed that Doripenem, Ertapenem, and Meropenem antibiotics had the highest frequency, whereas, the antibiotics of Piperacillin/Tazobactam and Piperacillin had the lowest frequency. Moreover, resistance to imipenem was observed to be semi-sensitive regarding the minimum inhibitory concentration in three isolates (76.4%). The exoS, toxA, exoT, exoY, and pvdA genes were observed in 40 (63.49%), 31(49.2%), 39 (61.9%), 56 (88.88%), and 50 (79.36%) isolates, respectively. In addition, there was a significant correlation between the antibiotic resistance pattern and distribution of toxin genes (P <0.05). According to the obtained results, it can be concluded that the antimicrobial resistance pattern could play an important role in the distribution of P. aeruginosa toxin genes isolated from burn wounds.

Immunotoxins such as pseudomonas exotoxin are Molecules with a unique structure like toxin-antibody part. These immunotoxins are two functional which crossing the cell membrane and enters the target cell and destroy the cell. Toxin-based treatments are a widespread research field and can have broad applications in the biology and public health. Immunotoxins act selectively against cancer cells and have a good potential for detecting and targeting cancer cells. Specific immunotoxins to target immune cells due to the selection type antibody and antibodies are responsible for the identification of the target cells. Cancer is becoming a major cause of death in most developed countries. In order to have a strong factor in cancer repression, that agent must target the cancer cells directly and specifically. Often, but not always, immunotoxins are produced for disabling and killing cancer cells, that this issue is one of new therapeutic approaches in recently. Clinical aims to designing and create new cancer therapies focused with this approach, a lot of information about the toxin and intracellular pathways have been obtained. So, toxins in medicine are useful for the treatment of human disease and study of professional cellular functions. So, immunotoxins have a high potential for cancer treatment. Other applications of immunotoxins, including immune system regulation and treatment of viral diseases and parasites diseases. More research is needed to improve the immunotoxin effects and to reduce their side effects. On the whole, with design creative, clever and experienced programs, many human diseases, particularly cancers can be in a short period of time and faster than other methods of treatment that the treatment of long, to be treated. Following the design and implementation of clinical trials, the effects of immunotoxins on animal tumorigenic models were performed. In fact, in this study, we focus on the use of protein-bound toxins with bacterial and herbal sources and more specifically Pseudomonas immunotoxins which attached to antibodies to target cancer cells.

Whooping cough is an acute contagious human respiratory disease especially in infants and children and is one of the ten major causes of death from infectious diseases. Despite reducing the risk due to vaccination with killed bacteria pathogen (Bordetella pertussis), increased disease emerged in recent decades indicates re-emerging due caused by genetic diversity of bacteria and the insufficiency of current vaccines. Therefore, the design of new and effective vaccines based on common strains of the population is essential. In this study the prevalent strain Iranian B.pertussis strains has been selected for gene amplification of pertussis toxin (PTX), the most important antigen of bacteria. The toxicity of the PTX related to its enzymatic activity therefore by site directed mutagenesis, the effective residues in the active site of the enzyme has been changed and the inactive and safe recombinant was produced.
Bacterial strain used in this study to determine the genome and gene amplification was selected from pathogenic strains isolated from Iranian patients from the pertussis reference laboratory of Microbiology of the Pasteur Institute of Iran. Genomic DNA was extracted by kit, ptx- s1(the enzymatic fragment of PTX) fragments amplified and inserted in pUC18. Site directed mutagenic primers were used for substitution of Arg 9 by Lys and Glu129 by Gly. The confirmed mutant ptx- s1 (mptx-s1) was sub-cloned into expression vector pET15b. The expression of recombinant protein in E.coli BL21 was induced by 0.5mM IPTG. The expression was analyzed by SDS-PAGE and immuno-blotting. The protein was puifird by Ni-NTA affinity chromatography under denature condition.
FINDINGS: Sequencing data and restriction enzyme analysis confirmed the gene constructing and mutations. The presence of a 28 kDa band in SDS-PAGE and immunoblot showed the expression of mutant PTX. The concentration of recombinant protein was 0.36 mg/ml.
The Recombinant protein which was obtained in this study provided the possibility of designing acellular vaccines on the basis of important antigens of prevalent strain of B.pertussis in Iran.

Stingrays belong to Chondrichthyes class.They live in freshwaters and oceans all over the world. They have venomous spines next to the root of the tail. Their barbed stingers covered with secretory cells that cause a large number of serious human injuries. In this review, we evaluate the toxinology of these venomous animals.
Some of inoculated venom symptoms included the immediate and intense pain, inflammation and skin necrosis, bleeding wounds, acute edema, salivation, nausea, vomiting, diarrhea, fever, headaches, muscle cramps, tremors, paralysis, dyspnea, cardiovascular collapse, local vasoconstriction, seizures, coma, and rarely death. The venom contains 5-HT, 5-nucleotidase, acetylcholine , phosphodiesterase, proteolytic enzymes against casein, gelatin, and fibrinogen, and several toxins such as cystatins, galectin, peroxiredoxin 6, orpotrin and porflan, and other peptids and proteins including alpha subunit haemoglobin, ganglioside GM2 activator, glutathione s-transferase µ, leukocyte elastase inhibitor, transaldolase, ATP synthase, nucleoside diphosphate kinase and type III intermediate filament. Galectin has a diverse functions including anticoagulant, procoagulant, platelet-modulating, myotoxic and haemagglutination activities. Cystatins are potent inhibitors of cysteine proteinases, including papain and the cathepsins. Hydrolysis of lipids through PLA2 activity is one of the most important functions of peroxiredoxin-6. Orpotrin and porflan have vasoconstrictive and inflammatory effects, respectively.
Stingray venoms have different toxins and bioactive molecules with diverse mechanisms of toxicities. A thorough understanding of the toxicities mechanisms and clinical manifestations of stingrays’ venoms will provide the ability to treat effectively and manage injuries with this animals by clinicians and toxinologists.

The sea urchins are classified in the echinoderms category because of their spiny skin. Saponins are the major responsible metabolites for Echinodermata biological activities . As mentioned before, about 80 species of sea urchins are venomous for human. Their spine, pedicellariae, and some other organs such as gonads and coelomic fluids contain different toxins and bioactive compounds. This review study have evaluated toxinology and bioactive compounds from the extracts, and treatment management of these venomous animals.
Contractin A, echinochrome A, echinometrin, major yolk protein (MYP), centrocins (I, II(, cathepsin B/X, strongylostatins (I,II), vitellogenin, UT841 toxin, spinochrome, and pedoxin as the prosthetic group of peditoxin are the most important compounds obtained from these animals.
Some people show poisoning symptoms following the ingestion of sea urchin gonads, especially during the breeding season. Some of these symptoms included allergies symptoms, as the first symptoms, nausea, diarrhea, vomiting, epigastric distress, severe headache, swelling of the lips and mouth, salivation, abdominal pain and some systemic symptoms such as hypotension, numbness and weakness. The most injuries by sea urchin can cause by contact to spines, which can create the various complications such as granuloma, synovitis, arthritis, edema, hyperkeratosis and even neuroma. Injuries by pedicellaria may cause severe pain, local edema, bleeding, lethargy, weakness, tingling, joint pain, aphonia, dizziness, syncope, general muscle paralysis, respiratory distress, hypotension and, infrequently death. After the injury by sea urchin, removing the spines and pedicellariae should be done to minimize the contact with the venom source, and subsequently the management of wounds and poisoning symptoms, as quickly as possible.
The venoms of some sea urchins have toxins and bioactive molecules that produce toxicity effects on their victims by a variety of mechanisms. Despite the various studies in toxinology field, on these animals, the comprehensive studies that led to the identification of pure toxins from their crude venoms are handful and unfinished and it is important to do further studies on this field, in the future.

Sea snakes belong to Hydrophiidae family mainly are found in tropical and subtropical waters of the world including the Persian Gulf. Their highly lethal venoms are more potent than snakes with terrestrial origin and contain complex mixtures of organic and inorganic bioactive substances, such as enzyme, and non-enzymatic proteins. There were limited studies on the venoms and toxins of sea snake; hence, the aim of this systematic review was to investigate the toxinological dimensions of sea snakes.
In order to investigate of the toxins of sea snakes, the “Hydrophis schistosus toxin", "Hydrophis cyanocinctus toxin", " Hydrophis lapemoides toxin", "Hydrophis spiralis toxin", and "Lapemis curtus toxin " terms were searched separately, in "PubMed database", in 10/08/2016 which obtained 32, 9, 2, 2 and 4 papers, respectively. The "Hydrophis gracilis toxin" term had no any results. For the “Hydrophis gracilis" term, two studies were obtained. The first one related to the sea snakes phylogenetic characteristics and the second one shared with other search results and well-connected with the issue. Some papers were similar in different searches. Of these, those studies were selected that had direct relevance to the subject .
The main isolated toxins from different sea snakes venoms included three-finger toxin (3FTx (short chain neurotoxins isoforms: AAL54893, AAL54892, ABN54806; long chain neurotoxins isoforms: AAL54894, AAL54895, P68416 , ABN54805), pelamitoxin (P62388), phospholipase A2 (both the basic and acidic PLA2), two phospholipases A2 (PLA2-H1 and H2), cysteine-rich secretory protein (CRISP), snake venom Zn2+metalloproteinase (SVMP), L-amino acid oxidase (LAAO), 5′-nucleotidase, Hydrophitoxins a, b and c, Hydrophis ornatus a, Hydrophis lapemoides a, PDGF and α- neurotoxins of rSN311, rSN316 and rSN285. Each toxin and protein family presents a wide range of pharmacological activities. Some of these neurotoxins were linked to acetylcholine receptors in the neuromuscular junctions. These toxins showed protease (gelatinase and caseinase) activities, and/or they produce the myonecrosis and biochemical and histopathological changes.
There is scant variability in the venom composition in the same and different species of sea snakes. Our study revealed that there is a rather simple venom profile with an affinity towards a lethal mixture of high abundance of neurotoxins and PLA2s, and lower amounts of toxins such as CRISP, SVMP and LAAO.

Clostridium perfringens are classified into five toxin types A to E, on the basis of production of Alpha, Beta, Epsilon and Iota toxins. Some strains are able to produce enterotoxin, can cause food poisoning in human. The bacteria are able to produce NetB and TpeL toxins which are virulence factors in necrotic enteritis in poultry. The aim of this study was to determine the toxin profile of C. perfringens strains isolated from packed chicken portions using Single and Multiplex PCR assays. In a crossectional study, 180 sample of chicken portions including wing (n=50), liver (n=50), neck (n=50) and gizzard (n=30) were collected randomly and examined for C. perfringens contamination. For this purpose all of samples were cultured on the 7% sheep defibrinated blood agar, TSN and TSC culture media. All of the isolates were investigated for the presence of alpha, beta, epsilon, iota toxin and virulence (tpeL and netB) genes. In the present study, 6 isolates out of 180 samples, were confirmed as C. perfringens by culture and molecular methods. All of the isolates (100%) were confirmed as cpa and cpb positive strains and belong to type C of C. perfringens. The netB gene was detected in 5 isolates (83.33%) and tpeL gene in three isolates (50%). Our findings show the majority of C. perfringens in broilers are belong to type C which produce necrotic enteritis in poultry and may be transmitted to human through poultry products.

Clostridium difficile infection (CDI) has been a major growing problem in hospitals in recent years. Detection of the source of Clostridium difficile strains is of importance for the control of the nosocomial spread of this microorganism. This study was done to identify C.difficile isolates by polymerase chain reaction, (PCR), ribotyping. The descriptive study was done during a period of 12 month. Seventeen C.difficile isolates were collected from patients hospitalized with suspected CDI in different wards of a general hospital. All samples were treated with alcohol and yeast extract broth. The treated samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA) supplemented with 5% sheep blood and incubated in anaerobic conditions, at 37 °C for 5 days. Prevalence and confidence intervals were calculated. Cdd-3, tcdA and tcdB genes were identified using PCR assay. PCR ribotyping was performed on C.difficile isolates. Out of 108 isolates 17(15.7%) were C.difficile. The prevalence of A+B+, A+ B- and A- B+ strains were 12(70.59%), 1(5.9%) and 4(23.9%) respectively. PCR ribotyping of 17 isolates showed different ribotype patterns The pattern of PCR ribotypes of isolates showed that the strains circulating in different wards of the hospital were different and may have been be endogenous or community acquired.

The sea similar of other earth environments have very different animals that life in them and any of that living beings have special characters. Notification about this special characters for all divers were necessary. Perform successful operation depend on this important and intelligent awareness. This study collected based on any books, articles and knowledge be about marin. Sea animals divided in two major group: poisonous and non poisonous. Poisonous sea animals such as sea snake, stone fish, portuguese Man-O” War, chironex and etc use of their toxins for defence. Sign and symptoms that produced by toxins are vary such erythema, endoration, pain or itching to anaphylactic shock and death. Contamination by toxins occur on two forms: active and passive. Complete explanation of this suggestion are reachable at this study. With pay attention to importance of poisoning prevention and their harmful complications, be awareness of sea animals characters for divers, swimmers and naval officers were seem necessary.

Staphylococcus aureus is one of the most important etiological agents of hospital and community acquired infections. The enterotoxins and toxin shock syndrome toxin (TSST-1) are among the most common virulent determinants of this bacterium. They are also well-known for their super-antigenic properties. The incidence of TSST-1 producing strains is also very alarming. The aim of this investigation was to survey the prevalence of TSST-1 gene in the clinical isolates of S. aureus recovered from hospitalized patients in Shohada hospital of Tabriz, Iran. During one year period, 1454 specimens obtained from hospitalized patients were investigated. After doing Isolation and purification, the isolates were identified by routine bacteriological methodologies.Their antibiotic susceptibility patterns were determined by agar disk diffusion method. Following genomic DNA extraction by boiling method, the presence of TSST-1 gene was analyzed by PCR. A total 100 S. aureus isolates were recovered (6.87%). Antibiogram results indicate that all of the isolates are sensitive to linzolid; 83% of them are resistant to meticillin. The prevalence rate of TSST-1 gene in the isolates is 20%. The high prevalence of TSST-1 gene in studied S. aureus strains and their circulation in the community can have a potentially alarming effect on general health of community.

Ribosome-inactivating proteins (RIPs), mostly from plants, are enzymes which depurinate rRNA, thus inhibiting protein synthesis. These proteins also depurinate other polynucleotides. The biological activity of RIPs is not completely clarified, and sometimes independent of the inhibition of protein synthesis. Some RIPs are potent toxins, the best known being ricin induce production of cytokines causing inflammation. RIPs are potentially useful in agriculture and medicine because they have anti viral activity. The mechanism of action and role in nature of RIPs are not completely understood, and we can expect more advancement in their practical application. We will be more acquainted with the structure and function of these proteins in this review.

Widespread medical usage of botulinum toxins has increased the need for the precise analysis of its biological activity. The aim of this study was production and crystallization of the botulinum type A toxins. In this study, Clostridium botulinum was grown and inoculated into the Tripticase Soya Broth culture media, under anaerobic condition and toxin production was monitored. The maximum yield of toxin was obtained after 96 hours, then toxin was harvested by acidifying the whole culture and centrifugation. The period of bacterial growth was extensively checked for toxin activity by mouse assay and crystallization was done at the same time. The results of this study showed that Clostridium botulinum grew in the above condition and produced toxin after 96 hours. The toxin produced in the low pH range of 4– 5.8 was stored as cube- shaped crystals. The crystallized toxin preparation was stable over time and maintained its biological activity after 4 years of storage in a temperature of 4-6 ° C. Clostridium botulinum type A toxin rapidly becomes inactive in the laboratory environment. Therefore, it is important to find a way to keep its biological activity. According to the results of this study, biological activity of the crystallized toxin remained stable for a long period of time. Thus, this method is useful for both preventive and research applications of botulinum toxin.