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In the present study, as a research background, the application of nanoparticles and herbal medicines in the treatment of diseases caused by Pseudomonas aeruginosa was investigated. The aim of this study was to determine the effect of zinc nanoparticles (Zn) impregnated with Khuzestan savory (Satureja khuzestanica) essential oil on the expression of lasR gene in clinical isolates of Pseudomonas aeruginosa, which are biofilm-forming bacteria, under extracellular conditions.

The present experimental study was conducted in 2019 on 150 non-repetitive and intermittent clinical samples suspected of Pseudomonas aeruginosa, which were collected from skin, blood, and urine samples of hospitalized patients in various wards of Imam Sajjad (AS) Hospital in Yasuj city. After the entry of 4 clinical strains along with a standard strain of Pseudomonas aeruginosa (ATCC 25922) as a sample, Khuzestan savory essential oil was prepared from Barij Essence Pharmaceutical Company (Kashan, Iran). Then, after identifying the Pseudomonas aeruginosa sample separated from the patients, PCR was performed to confirm the presence of lasR and DNA gyrase A genes, determine the antibiotic sensitivity pattern, broth microdilution test, checkerboard dilution, and agar test to determine the minimum inhibitory concentration, and real-time PCR to investigate the expression of lasR gene under laboratory conditions. The collected data were analyzed using Mann-Whitney U, T-Test, and Paired T-Test statistical tests.

According to the results of the antibiotic sensitivity pattern, the highest resistance was related to amikacin (30 μg), colistin (10 μg), and ciprofloxacin (5 μg), and the lowest resistance was related to ceftazidime (30 μg) and imipenem (10 μg). Also, Khuzestan savory essential oil and zinc oxide nanoparticles had a minimum inhibitory concentration of 256-512 μg/mL against standard strains and clinical isolates. The relative minimum inhibitory concentration index (FIC) was equal to 1, which represents an increase in effect. Also, the minimum bactericidal concentration (MBC) was four times the minimum inhibitory concentration (MIC). The highest MIC was related to zinc oxide nanoparticles and the lowest was related to the simultaneous use of essential oil and nanoparticles. In the combined mode of treatments, half the MIC of separate treatments was required. Also, with the reduction of the effect m.

The results indicated that clinical strains were highly resistant to some antibiotics but sensitive to others. Also, Khuzestan savory essential oil and zinc oxide nanoparticles were effective against standard strains and clinical isolates. The main component of this essential oil was carvacrol, which has antimicrobial properties. The results showed that the combination of essential oil and nanoparticles led to a stronger and more effective reduction in lasR gene expression. The study concluded that the combination of Khuzestan savory essential oil and zinc oxide nanoparticles is a promising complementary and alternative therapeutic approach for the treatment of chronic Pseudomonas aeruginosa infections.

Biosurfactants are amphiphilic surface active molecules that are produced by microorganisms such as the bacteria, fungi, and yeasts. Nowadays, these compounds are highly regarded in pest management due to their low toxicity, biological decomposition, optimal activity in harsh environmental conditions and environment-friendly nature. Recently, the insecticidal activity of biosurfactants obtained from different bacterial species has been reported. Therefore, considering the role of biosurfactants in the production of new insecticides and the environmental management of pests, in this paper, the use of biosurfactants in controlling agricultural pests and the direct antimicrobial activities of these compounds against plant pathogens have been investigated. Also, how the immune system of plants is stimulated by rhamnolipids and lipopeptides, which leads to plant resistance against plant pathogens, has been investigated. So that further research in this field can lead to the replacement of these biological pesticides instead of synthetic ones, and in the future, the effects of these pesticides on pests' histology and the optimization of their production can be studied.

Applying biological agents for increasing plant growth and their resistance to different tensions is of particular importance. In the present study, an attempt was made to isolate and identify plant growth-promoting bacteria from soil samples and to evaluate their ability to help the tomato plant cope with drought stress. Soil samples were collected from wheat and barley farms around Karaj and after isolation and initial purification of phosphate solubilizing, nitrogen fixing, and siderophore producing strains, they were isolated using PVK media culture, nifH gene PCR, and CAS-agar media culture, respectively. The identified isolates were then analyzed in terms of their drought tolerance in an environment containing polyethylene glycol. Finally, tomato seedlings were inoculated with bacterial isolates (belonging to the Bacillus, Brevibacterium, and Actinomycetes genera) before they were grown under drought stress at three osmotic pressure levels of 0, -0.4, and -0.8 MPa. Then, sodium and potassium ion contents of leaves, roots, and stems were measured using a flame photometer while calcium contents of the same organs were assayed through atomic absorption measurement. Results showed that all five isolates capable of dissolving phosphate, nitrogen fixation, and siderophore production were able to withstand drought up to -0.8 MPa osmotic pressure. All these isolates significantly affected drought stress and the intensity of ions reduction in leaves, roots, and stems compared with the control plants. The results of the present study showed that inoculation of the bacterial isolates considering their ability in siderophore production and nitrogen fixation may help the plant to resist drought stress.

Acinetobacter baumannii is an opportunistic pathogen and a component of gram-negative, aerobic, and non-fermentative gram-negative bacteria, which is found in the form of cocci or coccobacilli. Because these bacteria have few nutrients to grow, they can survive long periods in adverse conditions, on dry surfaces, as well as in aquatic environments. Acinetobacter is probably known as gram-negative bacteria on the surface of the genus. These organisms are difficult to stain and are often mistaken for gram-positive. Among the gram-negative bacteria that cause nosocomial infections (especially in the intensive care unit of the ICU), Acinetobacter species have received a great deal of attention over the last three decades (1-3).Acinetobacter baumannii OmpA binds to the host epithelium and mitochondria, causing mitochondrial dysfunction and swelling that is followed by the release of cytochrome c, leading to the formation of apoptosis, all of which contribute to cell apoptosis. OmpA, the most abundant surface protein in the pathogen, is also involved in complement resistance and biofilm formation. Key stress survival strategies and the potential for important virulence factors help increase bacterial survival inside and outside the host (1, 4). Most chromosomal AmpC beta-lactamases are found in Enterobacter, Serachia, Pseudomonas, Acinetobacter and, Citrobacter species. These enzymes belong to the C ambler classification and include the genes cmy, fox, mox, dha, acc, mic, family / related bil / lat (cit and act, mir (related to the ebc family)). They are (5). It is noteworthy that at tigecycline resistance levels in Acinetobacter baumannii isolates, its efficacy may be increased during treatment with tigecycline if the drug is exposed for a short time. Recently, mutations in the trm gene, encoding methyltransferases, have been associated with decreased tigecycline sensitivity in one Acinetobacter baumannii strain (6). Most strains of Acinetobacter baumannii are resistant to ampicillin, amoxicillin-clavulanic acid, anti-staphylococcal penicillins, broad-spectrum cephalosporins (except ceftazidime and cefepime), tetracycline,and, tetracycline. MDR resistance in Acinetobacter strains has become a global and growing problem. In previous studies in Iran, the rate of multidrug resistance has been more than 60% (7).

A total of 240 clinical samples (including blood, urine, sputum, respiratory secretions, urine, wounds, skin, etc.) were collected from patients admitted to different wards of Dey Hospital in Tehran. Samples were collected from patients who had been hospitalized for at least three days and had acquired the infection in a hospital setting and were transferred to a microbiology laboratory for evaluation. For initial isolation, clinical specimens were cultured linearly in McConkey Agar and Bloodagar media containing 5% sheep blood and incubated at 37 ° C for 24-48 hours (9). After the incubation period, the cultures were examined for macroscopic characteristics (appearance of the colonies) and microscopy using a hot staining technique. Then gram-negative bacilli were analyzed using biochemical tests.In order to extract the plasmid, the extraction kit made by Sina Clone Company, Iran was used. First, a colony of each isolate cultured on Müller-Hinton agar medium (manufactured by Merck, Germany) was inoculated with 5 ml of Luria Bertani Broth culture medium (manufactured by Sigma-Aldrich, USA) and stored for 13 hours in Incubated at 39 ° C. Then, the plasmid extraction steps were performed using the Cinnagen kit protocol. It should be noted that the resulting plasmids were stored at -20 ° C until PCR.

According to the results in Table 6, the higher the number of isolates containing mox gene, the more antibiotic resistance is observed. In fact, a significant relationship was found between the presence of this gene and antibiotic resistance. For colistin, which had the lowest resistance ratio of this antibiotic, fewer isolates had this gene. (Significance level 0.563) A semi-sensitive to colistin isolate containing both ox mox. Genes. One of the semi-sensitive isolates containing cefpeme contained only dha and no semi-susceptible isolates contained cit gene (significance level 0.853). With 1, 5 and, 14 isolates containing dha, cit and mox genes (significance level 0.802) (Table 6).

Previous studies have shown that resistance to various antibiotics is on the rise. For example, studies by Wang et al. (23) and Esmoliako et al. (24) in recent years have shown that most strains were sensitive to amikacin, ampicillin, sulbactam, ceftazidime, cefpime, gentamicin, imipenem, meropenem, piperacillin, tazobactam. . In contrast to the present study, which found a 98.3% resistance to ampicillin and the highest resistance among all antibiotics studied, Karimi et al. reported a sensitivity of 91.6% to ampicillin in 2020. Consistent with the results of the present study, the results of the study of money changers and colleagues (2019) in Shahrekord have also shown a high prevalence of resistance to carbapenems, impenem 78% and meropenem 44%. In this study, Acinetobacter baumannii had the highest resistance to cefipime and ceftazidime (100%) and the lowest resistance to tobramycin and meropenem (22). In the study of Karimi et al., The resistance to meropenem was 83.3% and to ceftazidime was 93.3%. (19) Salehnia et al. In their study showed 100% resistance to cefpeme (7).According to the antibiogram results of the present study and also the results of the mentioned studies, to date, some strains of Acinetobacter baumannii have become resistant to all common antibiotics used, which greatly limits the treatment of these infections. The only effective antibiotic used to treat infections associated with this bacterium is colistin, which is also increasing its resistance. In general, the findings of the present study indicate an increase in antibiotic resistance compared to previous studies. This high prevalence of resistance is due to the unnecessary prescription of antibiotics and the lack of appropriate infection control tools. This is very important in identifying antibiotic resistance genes. In addition, the selection of appropriate antibiotics based on antibiogram plays an important role in treating and preventing the spread of drug resistance.The results show a high percentage of MOX genes that are directly related to antibiotic resistance, however, the presence of these genes and their relationship with antibiotic resistance need further investigation. The high resistance of Acinetobacter baumannii to antibiotics was very worrying because it is difficult to control and treat this bacterium. The only effective antibiotic used to treat infections associated with this bacterium was colistin, which is also increasingly resistant.

Acinetobacter baumannii is one of the most important nosocomial and community-acquired pathogens that is resistant to many antibiotics. Toxin-antitoxin systems are regulatory systems that maintain bacteria and serve as new targets for Antimicrobial therapies are considered. The prevalence and transcription of these systems in clinical isolates is still unknown. The aim of this study was to evaluate the toxin-antitoxin system (mazEF, relBE and higBA) in Acinetobacter baumannii with multidrug resistance isolated from clinical specimens.

In this study, 60 isolates of Acinetobacter species were collected from 255 clinical specimens. Acinetobacter baumannii was identified by biochemical tests of oxidase, citrate, SIM and TSI. Antimicrobial susceptibility testing was performed by discard method and PCR method to identify genes in the toxin-antitoxin system (mazEF, relBE and higBA).

The highest resistance to ampicillin (98.3%) and the lowest resistance to colistin (35%). Resistance of more than 90% was observed in 12 antibiotics out of 15 antibiotics studied. Out of 60 isolates, 98.34% were resistant to more than 8 antibiotics and only one sample was sensitive to all. The mazEF, higBA, and relBE versions were present in approximately half of the Acinetobacter baumannii isolates studied. In all samples, more than 80% of the isolates containing each of the mazEF, higBA, and relBE genes were resistant to the antibiotics tested (with the exception of colistin, which was approximately 40%). The frequencies of mazEF, higBA and relBE genes were 24 (40%), 32 (53.33%), 35 (53.33%), respectively. 6 isolates (10%) were negative for all three genes.

Significant antibiotic resistance was observed among the isolates. Based on the presence of TA systems in half of A. baumannii isolates, these could be used as a novel target for antimicrobial therapy.

Nowadays, bovine mastitis has been recorded as an inflammation of the mammary gland and Staphylococcus aureus is the main pathogens responsible for contagious mastitis in ruminants. Presented study is looking for to assess the existence of methicillin-resistant and PVL positive Staphylococcus aureus from bovine milk and if there is any relation among the detected genes and antibiotic resistance or not? For this purpose, 100 milk samples were collected from cows affected with mastitis from four dairy farms in Fars province. The samples were transferred to MSA medium and incubated at 37 °C for 24 h. The pure colonies were identified by biochemical as well as molecular techniques using mecA, mecC and PVL gene. Then, the antibiotic pattern of the isolates was analyzed based on CLSI 2019 and Whonet program. Finally, the results were analyzed using statistical analysis. Totally, 6 S. aureus strains were detected which was confirmed by biochemical as well as molecular techniques. The isolates showed different antibiotic susceptibility patterns, most of the isolates were multidrug resistant, while, the strain No. 5 was the most sensitive one. Our results indicated presence of mecA gene in strains 1, 2 and 3, mecC in isolates 4, 5 and 6, and the PVL gene only in strain 4. Hence, it could be concluded that although different phages transporting PVL genes to the S. aureus isolate, in this special research we didn’t find any relationship between presence of mecA, mecC, and PVL genes with antibiotics resistant pattern.

Worldwide epidemic had a specific role on human health and economic; Corona, for example, as a huge pandemic had an expand effect on human health, social relation, economic, politic and environment with severe respiratory disorder and high mortality rate in the world. Due to importance of SARS-Cov-2, the present paper deals with the route of transmission, their relation with sex, prevention and control. Research shows that sex-linked immunological differences as well as sex hormones are effective in responding to infectious diseases. Since COVID- 19 is a critical global treat, therefore, in this article, factors such as restricting populations, appropriate medicine, forestry, population growth control, global ban on wildlife trade and nutrition, which are important factors in the spread of this organism are discussed. Results illustrated that sex hormones and presence of ACE2 receptors in male are the most important factors for developing the disease. Hence, it is recommended that they take more responsibility for the use of masks, regular hand washing with disinfectants, reducing the use of cigarettes and alcohol, and using foods containing vitamins such as A, C, E, zinc, Selenium and omega-3s and reduced presence in populations can prevent virus transmission.

Inroduction & Objective:

One of the biggest threats facing the aquaculture industry is bacterial infectious diseases and the use of antibiotics. Phage therapy is a reliable alternative to antibiotics to inactivate bacteria as major pathogens in the aquaculture industry. The aim of this study was to screen Vibrio species off the coast of Bushehr province and control this shrimp pathogen using phage.
 

For this study, water was sampled in 1398 from areas close to the coast of Bushehr province. Bacteria that cause Vibriosis were determined using biochemical tests and molecular sequencing. Bacterial selection was performed according to the results of antibiogram profiles of dominant bacteria and pathogens. TCBS was used to determine the phage titer of the culture medium and the plugs were counted 24 hours after incubation at 30 ° C.

5 bacteria (Vibrio alginolyticus strain SeqID, Vibrio xuii strain Z-03Phage, Vibrio alginolyticus SZ / 10 gene, Vibrio rotiferianus strain SRPR-Phage, Vibrio harveyi strain Z05 were isolated from Bushehr wastewater contaminated waters). Vibrio alginolyticus strain SeqID was selected as the dominant bacterial species according to the results of antibiogram profile determination, growth halo diameter and bacterial biochemical test of the studied species. Based on the results of 16srDNA molecular analysis, the isolated strain of the bacterium was 100% similar to Vibrio alginolyticus. Based on the results of the host domain, Vibrio alginolyticus strain Samira Phage was able to form plugs.

The isolated bacteriophage Vibrio alginolyticus strain Samira Phage had a bactericidal effect with a wide range against Vibrio bacteria identified from the shores of Bushehr, which indicates that this bacteriophage can be a good candidate for use in phage therapy Be against viberosis.

Most medical research to estimate the time interval after death depends on the physicochemical properties of the decomposition and the effects that environmental factors have on the decomposition process, but microorganisms settle in larger hosts and change over time. Found and known as microbial populations of decaying human bodies. Therefore, the aim of this study was to determine the presence of Clostridium perfringens in the liver of male and female corpses as an indicator for measuring the elapsed time of death.

In this experimental study that was conducted in 2019, 34 human bodies were found in different ways such as; Murder, suicide and suspected death. Samples were prepared and after homogenization cultured on blood agar and SPS media under anaerobic conditions using pack gas in Kendel Jar. Afterward they were characterized using gram staining, catalase and oxidase, and other diagnostic tests such as hemolysis, stormy fermentation, and nagler tests. Then for the confirmation of presence of Clostridum PCR was done using standard isolates from Razi Institute with code No: ATCC 13124 and finally relationship between the isolated bacterium and death process were evaluated.

The results obtained from the tests indicated that 8 bacterial strains were isolated from which 2 isolates were Gram negative, 2 isolates were Gram positive with different characterization of  Clostridium and 4 strains belonged to Clostridium based on 16SrRNA gene and product size of 722bp. In the samples taken, the time after death was reported to be between 19 and 192 hours according to the information contained in the files of the deceased by forensic medicine. In all four isolated samples, the time after death was determined to be more than 50 hours.

Although in normal condition it could be estimated the time of death according to examination of the body, freezing a corpse, cyanosis of the corpse and coldness of the body, but according to the results obtained from this study it could be concluded that There is a relationship between the presence of Clostridium strain in the liver and the time elapsed since death.

Arcobacter butzelri is known as the cause of enteritis, abdominal cramps, bacteremia, and appendicitis in humans, it is also the cause of enteritis and abdominal pain in animals. It has been introduced as the most dangerous species for human health by the International Committee on Food Microbiology and recently as an important zoonotic pathogen. The aim of this study was isolatation and characterization of Arcobacter butzelri based on pathogenic genes (tlyA, ciaB, mviN) in different seasons. Therefore, 238 samples were collected from the effluent of poultry slaughterhouse in Tonekabon, Iran. The suspected colonies were identified using biochemical test and then confirmed using the Polymerase chain reaction (PCR) technique. Out of 42 isolated of A. butzleri, the virulence genes were detected in 15 isolates. The results showed that ciaB gene was present in 13 strains with a frequency of 30.9%, mviN in 11 samples with a frequency of 26.2%, and tlyA gene in 9 samples with a frequency of 21.4%. The results also revealed that the highest frequency of A. butzelri was 8.4% in spring and the lowest rate was 1.2% in winter.

Listeria monocytogenes has been identified as a major cause of human Listeriosis, which has now become a major public health concern. So the main purpose of this study was to screen Listeria monocytogenes from ready-to-eat nugget samples to determine the seromolecular typing of the isolates. For this purpose, 40 chicken nuggets were bought from different area of Shiraz city and had transferred to the microbiological laboratory. 25 gram of each nugget was transferred to Palcom Broth medium and subsequently Palcam Agar. Then the isolates were identified by biochemical tests, also specific primers were used for seromolecular typing. For determination of antibiotic susceptibility of the isolates, effect of Oxacillin (OX1), Erythromycin (E15), Amikacin (AN30), Penicillin (P10), Tobramycin (Tob10), Gentamicin (Gm10), Ceftriaxone (CRO30), Clindamycin (CC2), Vancomycin (V30), Ciproflexocacin (CP5), Tetracycline (TE30) and Trimethoprim Sulfomethoxazole (SXT23) were checked on the isolates by using disk diffusion method and Vet01-A4 CLSI protocol. Data were analyzed by SPSS software and ANOVA test. Out of all isolated bacteria, 4 isolates from chicken nugget belong to Listeria monocytogenes was identified by biochemical tests. Based on molecular testing, Seromoleculartyping including 1/2a, 3a and 1/2b, 3b were identified and their frequency was 50%. Out of all the most antibiotics resistant belong to the (OX), (CRO), (P) were100 percent, 100 percent and 58/3 percent respectively and the less belong to (TE), (GM), (CP), (V), (SXT), (TOB), (AN), all of them was 100 percent.

Due to the increasing demand for the high quality of meat products, long shelf life, and minimum processing, therefore, this study aimed to evaluate the antimicrobial activity of the two standard strains Lactobacillus delbrukii subspp delbrukii )PTCC 1333( and Lactobacillus fermentum (PTCC 1744) on the most common isolated bacteria from meat. In this study, 50 meat samples including red meat, minced meat, and fish were purchased from different areas of Shiraz city. The samples were transferred to the lab and cultivated in Nutrient Broth as well as blood agar. Then the isolates were purified and the most common isolates identified using biochemical tests. The inhibitory activity of the two strains lactobacillus supernatant against the most common isolates was investigated by the good diffusion agar method. As well as to prevent the inhibitory effects of organic acids and H2O2, the supernatant was treated with sodium hydroxide and catalase enzyme. Finally, the most common isolates were identified by PCR molecular technique. Common bacteria were reported by the molecular test as Escherichia coli (16.6%), Enterobacter cloacae (16.6%), Hafnia alvei (50%), and Aeromonas salmonicida (16.6%). The greatest effect of lactic acid bacteria on Escherichia coli, Hafnia alvei, and Aeromonas salmonicida was observed. Among the two standard strains of lactobacillus, Lactobacillus delbrukii has a greater effect on isolated bacteria. The supernatant of the two lactobacilli, without neutralizing with Sodium Hydroxide and catalase, had antimicrobial activity against the most common isolates.

Biosurfactants are surface active biomolecules that are produced by microorganisms and have diffetent applications. In recent years, these biological molecules have received much attention due to their special properties such as specificity, low toxicity and easy preparation. The effect of biosurfactant produced by Staphylococcus hominis on red flour beetle larvae (Tribolium castaneum) was investigated. This experiment was done with three replications by different concentrations, and the results were analysed by SAS software. The results of the mean mortality percentage showed that the mentioned bacterial biosurfactant at a concentration of 10000 µg/g on the ninth day of treatment with 66.67% had the highest effect on larval mortality. LD50 was evaluated as 6395758/49, 1131823.60 and 15359.4 µg/g on the fifth, seventh and ninth days, respectively. The results showed that the biosurfactant produced by S. hominis had an acceptable ability to control T. castaneum.

Although bacteria and archaea are able to grow and adapted to the petrol reservoirs during severalyears, there are no results from microbial diversity of oilfields with high temperature in Iran. Hence, the present study tried to identify microbial community in non-water flooding Zeilaei (ZZ) oil reservoir.

In this study, for the first time, non-water flooded high temperature Zeilaei oilfield was analyzed for its microbial community based on next generation sequencing of 16S rRNA genes.

The results obtained from this study indicated that the most abundant bacterial community belonged to phylum of Firmicutes (Bacilli) and Thermotoga, whileother phyla (Proteobacteria, Actinobacteria and Synergistetes) were much less abundant. Bacillus subtilis, B. licheniformis, Petrotoga mobilis, P. miotherma, Fervidobacterium pennivorans, and Thermotoga subterranea were observed with high frequency. In addition, the most abundant archaea were Methanothermobacter thermautotrophicus. Discussion and

Although there are many reports on the microbial community of oil filed reservoirs, this is the first report of large quantities of Bacillus spp. from a high temperature oil reservoir.

Members of Acinetobacter genus are normal flora and the causal agent of the opportunistic nosocomial infections. The aim of this study was to investigate the ability to acquire drug resistance through efflux pump mechanism in multidrug-resistant Acinetobacter spp. and the role of PAβN (Phenyl Arginin β naphtyamid) as an efflux pump inhibitor.    In the cross-sectional descriptive study 83 clinical isolates and 62 environmental isolates were collected. Identification of the isolated bacteria was carried out by standard biochemical experiments and polymerase chain reaction (PCR) using specific primers of 16S rRNA and 16S-23S rRNA. Antibiotic susceptibility tests were conducted through disc diffusion and MIC test based on CLSI guidelines. The activity of the efflux pump was evaluated using the PaβN, and the adeABC gene frequency was assessed by PCR.   Of the total of the samples evaluated, 56 (67.47%) clinical isolates and 34 (54.84%) environmental isolates were identified as Acinetobacter spp. In accordance with the results of the antibiogram test, 100% of the isolates were resistant to cefotaxime and ceftriaxone. Only 7.13% of the clinical isolates and 5.89% of the environmental isolates were not multidrug-resistant (MDR). Prevalence of the adeB was 69.60%, 82.14%, and 76.80% in the clinical isolates and 50%, 85.30%, and 73.50% in the environmental isolates, respectively. Furthermore, tetracycline MIC was decreased in all resistant isolates in the presence of PAβN.   The results showed that the efflux pump could play a role in antibiotic resistance in Acinetobacter spp. isolates. Owing to the resistance of Acinetobacter isolates against cephalosporine, it is suggested to avoid prescribing.

Food is a vital substance which is important for human life. Although this vital matter could be a vehicle for transferring the microorganisms to human and Shigella is an important microorganism which could be cause of dysentery to human, the present study tried to isolate and characterized isolated Shigella from food.In this study 100 food samples including: 40 types of vegetables, 30 chicken, 20 minced meat and 10 fish have been collected. The samples were inoculated to gram negative broth and transferred to differential media such as MacConkey and Salmonella Shigella agar. Then the suspected colonies were identified using biochemical tests. Afterward, the isolates were characterized using ipaH gene by PCR technique. Furthermore, they were analyzed using serotyping techniques and the antibiotic susceptibility pattern were checked. Out of 100 foodstuffs the bacteria were detected only from vegetables. The isolates (n= 6) were confirmed by molecular techniques and all of them belong to the genus of Shigella. In addition the slide agglutination test showed that the isolates were belong to sh. dysentriae (n=1), Sh. sonnei (n=2), Sh. flexneri (n=2), and one non detectable. Furthermore, they showed different antibiotic pattern, as the isolate No.1 showed 100% sensitivity to the tetracycline and were resistant to the others Although foodstuffs are so important in transferring the microorganism, the monitoring of foods in market and greengrocery is necessary.

Diabetes is one of the most important metabolic diseases in the world that can ultimately lead to ulceration and amputation of lower limbs. The aim of this study was pigment extraction from isolated environmental bacteria and their effect on antibiotic resistant bacteria cooperated on infected diabetic foot.
In this project, dominant bacteria were identified using biochemical tests and antibiotic susceptibility was evaluated. Then, effect of different solvent was evaluated on the extraction of pigments using thin layer chromatography. Finally the affected bacteria were molecularly identified.
The results obtained from this study indicated that the most common isolated bacteria were Escherichia coli and Staphylococcus aureus. The results from antibiogram tests indicated that most of the gram positive isolates had same results and the gram negative was sensitive to Meropenem and Imipenem. Among extracted pigments, 4 different pigment which is effective on antibiotic resistant bacteria according to molecular technique were Brachybacterium sp. IARI-ABL-35, Brachybacterium nesterenkovii strain DSM 9573, Brevundimonas sp. NeomS2D Kocuria sp. YIM 75764.
According to biologic properties of bacterial pigments, we could use them in the treatment of various diseases.

Screening bacteria for bioactive compounds is the first step in the drug discovery programs. The aim of the present research was to achieve cytotoxic and antioxidant metabolites from actinobacteria of Persian Gulf sediments and to investigate the effects of combinations of seven treatments and six isolation media on the selective isolation process. A total of 395 actinobacterial isolates were collected from 12 sediment samples. Heat treatment and M6 medium were exhibited maximum efficiency of 34.59% and 32.82% isolation, respectively. Preliminary characterization results revealed the dominant distribution of Streptomyces like isolates in all investigated stations. Streptomyces isolates distribution followed a depth dependent frequency pattern. Approximately, 27.45% of the examined isolates could scavenge 90% of DPPH radicals in 1250 µg/ml final concentration. Exudated metabolites of potent isolates could scavenge DPPH radicals with IC50 ranges from 411 to 670 µg/ml. The results of cytotoxic activity showed that 54.9% of examined isolates exhibited LC50 lower than 1000µg/mL against Artemia cells. Extracted metabolites from 12 potent isolates exhibited LC50 range from 236.3 to 565.3 µg/ml. These results suggest the widespread distribution of the antioxidant and cytotoxic producing actinobacteria in Persian Gulf sediments and represent actinobacterial isolates as promising candidates for the discovery of microbial derived bioactive compounds.

Food borne diseases could threat human health. In these circumstances, Escherichia coli is one of the most important bacterium in food poisoning. The aim of this study was to evaluate and determine antibiotic resistant strains isolated from traditional food samples. In this study, 100 traditional food samples were evaluated for presence of E.coli and the isolates were identified and characterized using biochemical and serological tests. Then, antibiotic resistance pattern of the isolates were determined using Kirby-Bauer test based on CLSI 2013. The results indicated that 7% of the food samples were infected with E.coli, and out of that 3% were belonging to pathogenic group. Furthermore, the results indicated that 100% of the isolates were resistant to ampicilin and vancomycin, followed by cefixime (75%), tetracycline (62.5%), ceftriaxone, gentamycin, co-trimoxazole (25%), ciprofloxacin and chloramphenicol (12.5%). Escherichia coli is an important bacterium in food poisoning and presence of this bacterium in food could be threat the human health. According to the obtained results, for preventing the food spoilage, teaching and sanitary, preparation skills, transportation and depositing are necessary factors. In addition, isolated bacteria had resistance to the most antibiotics, although ciprofloxacin and chloramphenicol had more effect on the isolates in this geographical area, their side effects should be considered.

Many soil microorganisms are ale to solve unavailable phosphorus through metabolic activity and secretion of organic acids. This study was aimed to isolate tricalcium phosphate active solubilizing bacteria from wheat and barley farms in Marvdasht Plain. Materials &

This cross-sectional study was conducted on 50 barley and 50 wheat farms in Marvdasht Plain. The soil samples were enriched in NRIP media containing 10 percent tricalcium phosphate. The tricalcium phosphate solubilizing bacteria which produced halos on media were determined through biochemical tests, PCR and sequencing techniques. The activity of two active bacteria isolated from wheat and barley farms were analysed by HPLC method in order to investigate the production of secreted organic acids.

Overall 9 (18%) and 6 (12%) of the tricalcium phosphate solubilizing bacteria were isolated from the wheat and barley farms located at Marvdasht, respectively. The HPLC analysis showed that the microorganisms isolated from barely and wheats farms produce 4 and 3 respectively, different low molecular weight acids.

Since most of the tricalcium phosphate active solubilizing bacteria were isolated from the barely farms, these bacteria can be found in the soils in which less Phosphorus fertilizers were used. Screening of these bacteria in different farms and their identification can be useful in the production of biologic fertilizers and growth of plants in that area.

The main cause of spreading staphylococcal infections among patients is the healthy carriers working in hospitals. With the secretion of different sorts of toxins such as entrotoxin, this bacteria can provide the conditions for attacking on the host. The main objective of this study is identification of the characteristics and differences in the Staphylococcus aureus isolated from healthy carriers and from the patients on the basis of enterotoxin genes (sea-see). One hundred and twenty of the patients and 80 of healthy carriers worked in health centers of Gorgan, north of Iran, were investigated for S. aureus isolate. The isolates were evaluated by PCR for Enterotoxin Genes A-E (SEA to SEE). Enterotoxin genes (SEA to SEE) was found in 87.5% of the total isolates and the most frequent one was enterotoxin gene sea (N= 124). The prevalence of these isolates in healthy carriers was significantly higher than those of the patients. Based on the results, the high percentage of S. aureus isolated from clinical samples contains enterotoxin genes. Therefore, Human as the source and carrier of S. aureus is paramount importance, which is due to significant relationship between being toxigenic strains and the source of isolation.

Nowadays، overuse of the antibiotics culminates in existence of antibiotic resistant bacteria with high frequency. Pseudomonas aeruginosa is one of the most important pathogenic bacteria because of its resistance to beta lactam antibiotics. This character in Pseudomonas aerugionsa occurs because of extended spectrum β lactamase (ESBL) genes، which carry by transposons، plasmids and mutation. Therefore، the present study aimed to evaluate frequency of existence of OXA، PER، CTX-M1، CTX-M2 and CTX-M genes in pathogenic Pseudomonas aerugionsa isolates from different hospitals in Shiraz، Iran. The pathogenic bacteria were isolated from hospitals in Shiraz during six months. Then، the isolates were identified and their antimicrobial sensitivity assessed by antibiogram test. In addition، ESBL genes in Pseudomonas aerugionsa were tested by disk double diffusion. Afterward، DNA of the isolates was extracted and the genes amplified by PCR method. Out of 728 bacteria isolated from the clinical samples obtained from the patients of the hospitals in Shiraz، 62 Pseudomonas aeruginosa isolates harbored ESBL genes. The high level resistance character of Pseudomonas aeruginosa isolates was related to erythromycin، ampicillin، tetracycline and imipenem. In additiont highest frequency of ESBL was related to OXA-10، PER-1، CTX-M1، CTX-M2 and CTX-M3. All of the antibiotic resistant genes of Pseudomonas aeruginosa located in choromosom. Hence، more investigations on ESBL genes such as OXA and the other genes in Pseudomonas areuginosa are necessary.

The endophytic bacteria are group of bacteria، which live in plants tissues without any apparent harmful effects to the plants. Recently they have been isolated from different parts of plants with capability to produce anti fungi or bacterial activity. Nowadays، the endophytes instead of the fertilizers and germicidal chemical substances are used in agriculture hence the present study evaluated the presence of these organism in Glycine sp. in order to investigate their possible antifungal metabolites. First، in the present study، endophytic bacteria were isolated from the stems and leaves of soybean using serial dilutions on the brain heart infusion agar. Then، the isolates were evaluated for ability to produce anti microbial metabolites against two fungal pathogens: Alternaria alternate (PTCC 5224) and Fusarium solani (PTCC 5284) based on parallel streak and well diffusion agar methods. The bacterial strains with ability to produce antimicrobial metabolites were identified using Api 20E، 20NE kites and then their growth curves were studied. Totally، 39 bacterial endophytes were isolated from stem and leaves of the soybean plants among wich 20 belonged to the stems and 19 were isolated from the leaves. Among، all bacterial isolates 3 showed the antimicrobial effect which identified with Api kits and they belonged to the genus of Pseudomonas. Among the bacteria with anti microbial activity Pseudomonas aeroginosa was the most effective on the fusarium solani. In addition، the results obtained from the growth curves of the bacteria indicated that most of the microorganisms produced their compounds at the first 18 hours which was continued up to 72 hrs in some isolates. Discussion and The present study showed that soybean plant containing endophytic bacteria had the ability to produce antimicrobial effect against plant pathogens and that the produced compounds can be used in further researches.