Showing 8 results for Bacteria
Salari M.h., Sharifi M.r., Golzari M., Sarabadi A.a., Kafilian H,
Volume 4, Issue 1 (4-2006)
Abstract
Background and Aim: As the population of the world increases, it is essential that food production keep pace. It will be necessary not only to produce more food, but also to maintain this food so that it is safe and wholesome for human consumption. The purpose of this study was to investigate the rate of Coliform, Staphylococcus aureus, Mould, Yeast and other aerobic and mesophilic bacteria as contaminats of milk and milk products in Yazd province.
Material and Methods: In this study a total of 198 different samples including Milk (24.2%), Yoghurt (21.2%), Cream (12.1%), Cheese (18.2%), Ice cream (12.1%) and dairy powders (12.1%) were investigated by culture method and biochemical tests. Then obtained data were analyzed by SPSS and χ2 programs.
Results: On the basis of our findings, of the total samples, 136 cases (68.7%) were desirable, 48 cases (24.2%) acceptable and 14 cases (7.1%) undesrable. Microbial contaminants of undesrable samples were coliform (7.1%), Staphylococcus aureus (6.1%) and yeast (6.1%). Meanwhile, the results of χ2 Statistical analysis test, showed significant different between contamination rate and kind of Milk products (df = 5, χ2 = 17.75, P<0.005(.
Conclustion: It seems that despite the efforts, which have been done for prevention of food contamination in Yazd province, it is still considered as a threat for people Health.
M Mahami, M Moheb Ali, H Keshavarz, H Hajaran, B Akhoondi, Z Zarei, S Charedar,
Volume 4, Issue 1 (4-2006)
Abstract
Background and Aim: As the population of the world increases, it is essential that food production keep pace. It will be necessary not only to produce more food, but also to maintain this food so that it is safe and wholesome for human consumption. The purpose of this study was to investigate the rate of Coliform, Staphylococcus aureus, Mould, Yeast and other aerobic and mesophilic bacteria as contaminats of milk and milk products in Yazd province.
Material and Methods: In this study a total of 198 different samples including Milk (24.2%), Yoghurt (21.2%), Cream (12.1%), Cheese (18.2%), Ice cream (12.1%) and dairy powders (12.1%) were investigated by culture method and biochemical tests. Then obtained data were analyzed by SPSS and χ2 programs.
Results: On the basis of our findings, of the total samples, 136 cases (68.7%) were desirable, 48 cases (24.2%) acceptable and 14 cases (7.1%) undesrable. Microbial contaminants of undesrable samples were coliform (7.1%), Staphylococcus aureus (6.1%) and yeast (6.1%). Meanwhile, the results of χ2 Statistical analysis test, showed significant different between contamination rate and kind of Milk products (df = 5, χ2 = 17.75, P<0.005(.
Conclustion: It seems that despite the efforts, which have been done for prevention of food contamination in Yazd province, it is still considered as a threat for people Health.
K Ghazvini, M Malek Jafarian, M.h Amouzegar,
Volume 5, Issue 4 (3-2008)
Abstract
Background and Aim: Superinfection of burn wounds is a major cause of mortality and morbidity in hospital burn units. It is crucial for every burn center to determine the pattern of microbial colonization in burn wounds and the antimicrobial sensitivity profiles. This study was carried out on patients admitted to the Burn Unit of Emam Reza University Hospital, Mashhad, with the aim of verifying the pattern of microbial colonization of burn sites and determining the antimicrobial sensitivity of the isolated bacterial species.
Materials and Methods: In this study a total of 344 samples were obtained from 126 burn patients. After isolation and identification of bacteria, we used an agar diffusion method to determine sensitivity against 14 common antibiotics.
Results: Our results showed that 27.7% of the wounds were sterile at the time of the first dressing, but the rate of contamination increased with time so that only 5% of wounds were sterile by the third week Pseudomonas aeroginosa was the most frequently isolated species (31.7%). Most of bacteria were resistant to amoxicillin ciprofloxacin and imipenem emerged as the most effective antibiotics.
Conclusion: The common occurrence of gram-negative bacilli and staphylococci together with the sensitivity patterns show that we are far from eradication of wound infections, so there is an urgent need for improved infection control practices and policies.
M Shakerkhatibi, H Ganjidoust, B Ayati, E Fatehifar,
Volume 6, Issue 3 (2-2009)
Abstract
Background and Aim: Acrylonitrile (ACN) is widely used as a main raw material in the Acrylonitrile-Butadiene-Styrene (ABS) resin-manufacturing units and other industrial and commercial processes. ACN, due to its toxicity, is not easily decomposed by microorganisms. The discharge of improperly treated ACN-containing wastewater into a natural water body may cause serious environmental problems and severe adverse impact on the aquatic ecology. This study attempts to isolate and identify bacteria which utilize ACN as the sole source of carbon and nitrogen from the activated sludge of petrochemical wastewater treatment system. The performance of the isolated strains in treating different initial ACN concentrations was also investigated under aerobic conditions. In addition, the performance of biodegradation and the metabolic intermediates and end-products in the process were determined.
Materials and Methods: Experiments were conducted with three batch reactors, the volume of each one being 250 mL. The activated sludge samples as a microbial seeding were taken from the return sludge line of the aeration tank of the wastewater treatment facility in Tabriz Petrochemical Complex. Phosphate-buffered medium (PBM) was used to make available minerals and trace elements, and ACN was used as the sole carbon and nitrogen source for microbial growth. R2A medium was used to obtain pure colonies, and to identify the isolated strain, Gram staining and microscopic examination followed by biochemical and physiologic analyses using selective media such as O-F glucose, MacConkey agar, TSI agar, EMB and SS agar, nitrate reduction, gelatin liquefaction, lactose fermentation, oxidase, catalase and SIM were used. In the final stage, the performance of biological systems in degrading different initial concentrations of ACN and its intermediate and end-products were investigated.
Results: The findings indicated that when the ACN concentration was 500 mg/L, the average removal efficiency after 46 and 70 h reached 46% and 98%, respectively. But at an initial concentration of 700 mg/L, the removal efficiency of the ACN in the biological system was 50% after 46 h and 98.6% after 94 h . However, when the ACN concentration was increased to 1000 mg/L, the removal efficiency after 46 and 94 h was only 30% and 40%, respectively, and after 118 h of reaction, the remaining concentration of ACN was about 580 mg/L. Furthermore, the results of isolation and identification experiments revealed that at the optimum operation of the biological system the strain belonging to the gamma group of Proteobacteria as Pseudomonas putida had the best ability to degrade ACN.
Conclusion: Biological processes can degrade ACN and the abilities of different bacterial strains in this degradation vary. The rod-shaped Gram-negative P. putida could easily adapt to ACN concentrations up to 700 mg/L and utiliz ACN and its intermediate- and end-products as a carbon and nitrogen source for growth in the process. Thus, this strain is expected to play an important role in aeration tanks for treating ABS resin-manufacturing wastewater.
F Kafilzadeh, S Abolahrar, M Kargar, M Ghodsi,
Volume 8, Issue 1 (6-2010)
Abstract
Background and Aim: Agricultural and industrial activities, as well as population growth, have resulted in increases in the amounts of pollutants in the environment, the human body, and other organisms. Cadmium is one of the common heavy metals entering the biological cycles through different paths causing disease in humans, animals and plants. This study aimed at determining cadmium levels and physicochemical and biological factors in water and sediment samples, as well as determining relationships between culturable bacterial counts and cadmium toxicity and assessing bacterial resistance/tolerance spectrum through MIC and MBC.
Materials and Methods: Surface water and sediment samples were taken from five stations in areas believed to be polluted along the Kor River. The stations included 1. Dorudzan Dam outflow, 2. Petrochemistry Bridge, 3. Khan Bridge, 4. Doshakh Bridge, and 5. the mouth of the Kor River to the Bakhtegan Lake. Two sets of samples were taken. Set 1was used for measuring cadmium level, physicochemical and biological factors, while Set 2 was used for the isolation and identification of cadmium resistant/tolerant bacteria and determination of their resistance spectrum. Pure cultures of each bacterial species were prepared and the more resistant bacteria were identified by exposure to media with different cadmium concentrations.
Results: Stations 2 and 3 were found to be significantly more polluted with cadmium than the other 3 stations (p<0.001). The cadmium level in sediments of all the stations was higher than in water (p<0.001) and quite high as compared with the existing standards. The data also showed a lower BOD/COD ratio in the last 2 stations and higher phosphate levels in the last 4 stations. As compared to control, the bacterial count decreased in the presence of 1 mM cadmium chloride solution (p<0.001). Cadmium-resistant bacterial counts were higher in stations 3 and 5 than in the others (p<0.001). The most cadmium-resistant/tolerant bacteria were P. aeruginosa ETs and Bacillus ABs with MIC 6 and 4 and MBC 7 and 5 mM, respectively. The most resistant bacteria were gram-negative, isolated from the sediments.
Conclusion: Cadmium pollution, especially in stations 2 and 3, are due to man's activities. Although many bacterial types were found to be sensitive to cadmium in this study, some of them showed resistance/tolerance to it to different extents. Our findings also show that unlike water, which is an unstable environment, sediments are stable and provide a suitable environment for bacteria to form biofilms as a way to reduce cadmium accumulation. The most resistant bacteria were found in the stations with the highest cadmium concentrations. This may be a result of cadmium-resistant gene expression in the presence of this heavy metal. The use of these resistant strains in biofilters and wastewater bioremediation can potentially help to reduce cadmium pollution, a problem in some rivers.
M Mosaferi, M Shakerkhatibi, A Mehri Badloo,
Volume 8, Issue 4 (2-2011)
Abstract
Background and Aim: Recently the use of heterotrophic plate count (HPC) has received much attention as a supplementary indicator of the MPN test in water quality control. The US Environmental Protection Agency (USEPA) has declared 500 cfu/mL as the maximum acceptable level for heterotrophic bacteria in distribution networks. Currently the HPC determination is not among the routine control items in Tabriz city and there is no published information on the presence of heterotrophic bacteria in that city's potable water. In this study the presence of HPC in potable water main was determined in Tabriz city, Iran.
Materials and Methods: A total of 50 water samples, representing drinking water of the whole city of Tabriz, were taken randomly from different districts of Tabriz city and their HPC, coliform, residual chlorine, turbidity, temperature, and pH were measured. For the heterotrophic bacteria the R2A and Nutrients Agar culture media were used, while the spread plate count method was used for the HPC test. The statistical tests used for data analysis were the t-test and regression.
Results: In 50% of the samples heterotrophic bacteria were present. In 6 districts the HPC was higher than 500 cfu/mL. Based on Nutrient Agar and R2A, the HPC indicator in Tabriz drinking water was 184±340 and 154±315 cfu/mL, respectively, the growth rate being higher in the former medium. There was a significant correlation between the HPC and residual chlorine in both media (for Nutrients Agar, p<0.05 R= -0.347, and for R2A, p<0.05 R= -0.312). Also, there was a significant positive correlation between the HPC and pH (p<0.05). Further analysis of the data showed that the correlation between HPC values in both media was also significant (p<0.95, R= 0.95).
Conclusion: The presence of heterotrophic bacteria in 50% of the water samples tested indicates that drinking water contamination with these bacteria is a public health problem in Tabriz city. As a result, monitoring of HPC at least once every 6 or, at least, 12 months, together with coliform bacteria, and the comparison of the results over time can help to better determine water quality in the distribution system, as well as boost the system operation and ensure drinking water with a high quality.
Sevan Avadisians, Mojtaba Salouti, Mohammad Mehdi Soltandalal, Ronak Bakhtiari,
Volume 10, Issue 1 (7-2012)
Abstract
Background and Aim: Iron nanoparticles are broadly used in medical science, particularly in synthesis of fluorescence biomarkers, cancerous tumor therapy by hyperthermia, and as a contrast agent in MRI. Physical and chemical synthesis methods currently used to produce nanoparticles cause environmental contamination. Certain bacteria are capable of synthesizing significant amounts of iron nanoparticles, quite in conformity with the principles of green chemistry. The objective of this study was to isolate iron nanoparticle-producing magnetotactic bacteria from Arjin ore in Zanjan Province, Iran
Materials and Methods: Serial dilutions were prepared from the soil of iron ore and inoculated on a combined solid agar culture medium specifically used to isolate magnetotactic bacteria. This was followed, after incubation at 30 degree for a week, by transferring samples of colonies to special liquid culture media. After three weeks of incubation, the samples were examined by Gram staining, XRD and of scanning electron microscope (SEM).
Results: The existence of iron nanoparticles was confirmed by analysis of XRD graphs. Furthermore, scanning electron microscopy pictures proved the shape of bacteria and extracellular accumulation of iron nanoparticles produced by them.
Conclusion: Magnetotactic bacteria isolated from Arjin ore in Zanjan Province, Iran are capable of biosynthezing iron nanoparticles.
Mehdi Ahmadi, Farzad Amiri, Zahra Naghibifar, Mohammad Mehdi Mansouri, Armin Naghipour,
Volume 23, Issue 2 (9-2025)
Abstract
Background and Aim: Excessive use of antibiotics increases bacterial drug resistance in patients with diabetic foot ulcers. Therefore, the use of natural compounds as supplements may be effective in managing diabetic wound infections alongside conventional drugs. This study aimed to evaluate the effectiveness of Sarizh ointment (containing natural ingredients) on the healing of infected diabetic foot ulcers.
Materials and Methods: This single-center randomized clinical trial was conducted on patients with diabetic foot ulcers hospitalized in the infectious disease department of Imam Reza Hospital, Kermanshah. Microbial cultures were obtained from the foot ulcers of all patients using the punch method. Patients were randomly assigned to two groups: control and intervention. The control group received systemic antibiotics and a placebo dressing, while the intervention group received systemic antibiotics in addition to Sarizh herbal compounds as a supplement.
Results: A total of 30 patients with a mean age of 58.93 ± 6.15 years were included. The duration of hospitalization was 17.40 ± 3.06 days in the control group and 16.87 ± 3.52 days in the intervention group. The healing time was 17.34 ± 2.87 days in the control group and 12.06 ± 2.40 days in the intervention group. Sarizh ointment significantly reduced the healing time of diabetic foot ulcers (p = 0.001). Post-discharge bacterial cultures were negative, and complications such as redness, discharge, and pain at the wound site were similar between the two groups.
Conclusion: Sarizh ointment can be used as a complementary treatment alongside standard therapy to reduce healing time and promote wound recovery in patients with diabetic foot ulcers.
