Survival and Histamine Production by Histamine-Forming Bacteria Exposed to Low Doses of Gamma Irradiation

2020 ◽  
Vol 83 (7) ◽  
pp. 1163-1166
Author(s):  
P. RAMAKRISHNA REDDY ◽  
SANATH H. KUMAR ◽  
P. LAYANA ◽  
BINAYA BHUSAN NAYAK

ABSTRACT Histamine poisoning occurs when fish containing high amount of histamine are consumed. Because histamine is thermally stable, control of histamine-forming bacteria in seafood is an appropriate strategy for preventing the formation of histamine. One prevention method is the use of gamma irradiation on the histamine formers. To understand the effect of gamma irradiation on the histamine-forming bacteria, laboratory isolates of the prolific histamine formers Morganella morganii, Klebsiella variicola, and Proteus vulgaris were exposed to various doses of gamma radiation in nutrient broth and tuna muscle spiked with histamine formers. None of the test bacteria survived in tuna muscle irradiated at 2.0 kGy. K. variicola was highly sensitive to gamma irradiation and was eliminated at a dose of 1.5 kGy. Histamine production also was reduced significantly as the radiation dose increased. These results suggest that gamma irradiation can effectively eliminate histamine-forming bacteria and reduce the threat of histamine poisoning from seafood. HIGHLIGHTS

2000 ◽  
Vol 57 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Marta Helena Filet Spoto ◽  
Cláudio Rosa Gallo ◽  
André Ricardo Alcarde ◽  
Maria Sílvia do Amaral Gurgel ◽  
Lucimara Blumer ◽  
...  

This work evaluated the effect of gamma radiation on reducting the population of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium in ground chicken breast stored under refrigeration. The experiment included a control and 4 doses of gamma radiation (2.0, 4.0, 6.0 and 8.0 kGy) along with 5 periods of storage under refrigeration (1, 7, 14, 21 and 28 days). Samples of ground chicken breast were inoculated with Staphylococcus aureus (ATCC 14458), Escherichia coli (ATCC 11105) and Salmonella typhimurium (ATCC 0626), irradiated at temperatures between 4 and 8°C and stored under refrigeration (5°C) for 28 days. The increased radiation dose and period of storage under refrigeration caused a reduction of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium populations in the ground chicken breast. Mean radiation D values determined for Staphylococcus aureus and Escherichia coli were 0.41 and 0.72 kGy, respectively. Gamma irradiation was an effective treatment for chicken meat conservation because the radiation dose of 6.0 kGy kept the ground chicken breast within the microbiological limits established by the Brazilian legislation, for up to 28 days under refrigeration.


2017 ◽  
Vol 105 (7) ◽  
Author(s):  
Shahryar Malekie ◽  
Behrooz Salehpour

AbstractIn this experimental work, the effect of gamma irradiation on the capacitance and impedance of some commercial capacitors namely electrolytic, MKP, and MKT capacitors in different radiation doses up to 120 kGy and a wide range of frequencies between 42 Hz and 5 MHz were studied. Results showed that the capacitances of the electrolytic capacitors exhibited a linear decrease by increasing the radiation dose and frequencies, which can be used for high dosimetry purposes, but non-ceramic capacitors as MKP and MKT showed much higher radiation resistance, particularly for the frequencies less than ~1 MHz.


2015 ◽  
Vol 7 (1) ◽  
pp. 66-71
Author(s):  
Ayman EL-FIKI ◽  
Gamal EL-METABTEB ◽  
Abdel-Hadi SAYED ◽  
Mohamed ADLY

Nicotiana alata anthers cultured on different modified media based on MS, MT and N were used to obtain haploid plants through direct and indirect ways. The haploid plants resulting on MS medium ranged from 52% - 80%, on MT medium ranged from 32% - 52% and on N medium ranged from 28% - 44%. Accordingly, the best medium used for haploid induction was MS supplemented with 0.2 mgl-l NAA + 0.5 mgl-l KIN. On the other hand, MS medium supplemented with 0.4 mgl-l NAA + 0.5 mgl-l KIN or 1.0 mgl-l BAP + 0.5 mgl-l NAA were the best mediums for callus induction and plant regeneration, respectively. Morphologically, the leaf size, stem highest and diameter, flower size and diameter, anther length and number were about 67% of the diploid plants growth. Irradiated anthers with doses of 0, 2.5, 5, 7.5, 10, 15, 20 and 25 Gy caused reducing the number of haploid plants with increasing gamma radiation dose. For the haploid plants irradiated with same doses, the mortality percentage of bud survival was increasing with increasing gamma radiation dose. The irradiated callus with doses of 0, 5, 10, 15 and 20 Gy was affected negatively on growth rate and morphology. Proline content in irradiated plantlets increased with increasing gamma radiation dose. As well, total soluble protein content was increased with gamma irradiation up to 10 Gy. However, the higher doses caused a severe decrease of total soluble proteins. The production of proline and total soluble proteins in haploid plants were 48.6% and 69.5%, respectively comparing with diploid plants.


2011 ◽  
Vol 74 (4) ◽  
pp. 641-644 ◽  
Author(s):  
CHRISTOPHER H. SOMMERS ◽  
KATHLEEN T. RAJKOWSKI

Foodborne illness due to consumption of contaminated seafood is, unfortunately, a regular occurrence in the United States. Ionizing (gamma) radiation can effectively inactivate microorganisms and extend the shelf life of seafood. In this study, the ability of gamma irradiation to inactivate foodborne pathogens surface inoculated onto frozen seafood (scallops, lobster meat, blue crab, swordfish, octopus, and squid) was investigated. The radiation D10-values (the radiation dose needed to inactivate 1 log unit of a microorganism) for Listeria monocytogenes, Staphylococcus aureus, and Salmonella inoculated onto seafood samples that were then frozen and irradiated in the frozen state (−20°C) were 0.43 to 0.66, 0.48 to 0.71, and 0.47 to 0.70 kGy, respectively. In contrast, the radiation D10-value for the same pathogens suspended on frozen pork were 1.26, 0.98, and 1.18 kGy for L. monocytogenes, S. aureus, and Salmonella, respectively. The radiation dose needed to inactivate these foodborne pathogens on frozen seafood is significantly lower than that for frozen meat or frozen vegetables.


2018 ◽  
pp. 37-40
Author(s):  
Phuong Thao Tien Nguyen ◽  
Anh Hung Tran ◽  
Van Tam Le ◽  
Huu Thao Phung ◽  
Phan Quynh Anh Nguyen

Objective: To evaluate the effect of gamma sterilization and its effect on microscopic structure of deeply frozen dog skull. Subjects and methods: 50 pairs of dog skull fragments have the same size,which were taken symmetrically through the midline of the skull, were divided into two lots. Evident lot consisting of 50 pieces are just deeply frozen, not irradicated. Experimental lot which was composed of 50 pieces were deeply frozen and exposed to 25kGy of gamma radiation. Afterwards, to evaluate the effect of gamma sterilization and compare the alter of bone matrix between lot groups. Results: After gamma irradiation, all dog skull fragments were negative with bacteriological examination. In microscopic scale, no difference was found between the two lots and there was no structural change in the irradiated fragments of all dog skull. Conclusion: Gamma irradiation with 25 kGy: (i) It has the ability to kill bacteria completely in the type of bacteria commonly infected tissue. (ii) It does not alter the structure of dog skull in microstructures. Key words: dog skull, gamma, sterilize


2016 ◽  
Vol 5 (4) ◽  
pp. 308-317
Author(s):  
Hagos Tesfay ◽  
Erika S. Bronze-Uhle ◽  
Augusto Batagin-Neto ◽  
Anna C. Véron ◽  
Thomas Geiger ◽  
...  
Keyword(s):  

Author(s):  
Soham Hazra ◽  
Shouvik Gorai ◽  
V Umesh Kumar ◽  
Sudip Bhattacharya ◽  
Anirban Maji ◽  
...  

Author(s):  
Matteo Montanari ◽  
Sara Pipponzi ◽  
Pietro Livi ◽  
Antonio Prodi

Abstract This work describes mass recovery processes of flooded archival materials at industrial scale. The presence of fungi on paper represents a threat to the integrity of the document because they degrade cellulose, one of the main components of paper. Gamma radiation treatments are investigated as mass disinfection agents for their high penetrating power, speed of treatment, and absence of risk due to chemical residuals. We compared two different recovery processes: thermal drying followed by gamma irradiation and gamma irradiation followed by thermal drying. Both these processes were conducted simultaneously on naturally contaminated archival items and on paper specimens artificially contaminated with species test. Efficacy was assessed by culture method and ATP assay, right after the treatments and after four years of storage at room temperature. Coupling gamma irradiation with a drying step with dry heat at 55–60 °C reduces the fungal loads on natural items up to levels close to the detection limits, and the reduction is maintained after four years. On artificial specimens, spore germination is completely inhibited, mycelia growth is also highly affected, but the melanised test species appear to be more resistant. A synergistic effect between gamma irradiation, water content, and thermal drying is highlighted in this paper.


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