Molecular detection of virulence genes in Campylobacter species isolated from livestock production systems in South Africa          下载免费PDF全文

Bongekile NGOBESE  Oliver Tendayi ZISHIRI  Mohamed Ezzat EL ZOWALATY 《农业科学学报》2020,19(6):1656-1670

Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.  相似文献   

Beneficial effects of Bacillus subtilis on water quality,growth, immune responses,endotoxemia and protection against lipopolysaccharide‐induced damages in Oreochromis niloticus under biofloc technology system     

Ghasem Mohammadi  Taida Juliana Adorian  Gholamreza Rafiee 《Aquaculture Nutrition》2020,26(5):1476-1492

The present research explored the effects of Bacillus subtilis on water quality, growth, immune responses, endotoxemia and protection against lipopolysaccharide (LPS) damages in Nile tilapia Oreochromis niloticus under biofloc system. B. subtilis was added at 0, 1, 2, 3 and 4 grams (1.19 × 10⁸ CFU/g) per kg of basal diet, named T1 (control), T2, T3, T4 and T5, respectively, and fed to fish (14.82 ± 0.42 g) for 50 days. The concentrations of TAN, NO₂ and NO₃ were significantly reduced, and fish fed probiotics displayed significantly better growth performances versus the control, concomitantly with significantly enhanced activities of digestive enzymes. They also showed significantly declined serum glucose and cholesterol vice versa significantly improved immune responses (total protein, albumin, globulin, lysozyme, alternative complement, protease, immunoglobulins, alkaline phosphatase and respiratory burst), antioxidant capacity (superoxide dismutase, total antioxidant capacity, malondialdehyde) and skin mucus parameters (total protein, lysozyme, alternative complement, protease, immunoglobulins). Meanwhile, significantly lower endotoxin (LPS) concentrations were detected in the intestines and serum of fish fed probiotics. LPS challenge induced profound oxidative stress and impaired immune responses. Interestingly, probiotic alleviated LPS‐induced damages and restored mentioned parameters. In conclusion, B. subtilis effectively enhanced fish production, immunity and protection against LPS‐induced damages in tilapia under biofloc system.  相似文献   

Establishment, validation and use of the Kielstein-Rapp-Gabrielson serotyping scheme for Haemophilus parasuis   总被引：6，自引：0，他引：6  

Rafiee M  Blackall PJ 《Australian veterinary journal》2000,78(3):172-174

OBJECTIVES: To produce antisera to the 15 recognised reference strains of the Kielstein-Rapp-Gabrielson (KRG) serotyping scheme for Haemophilus parasuis, validate those sera and use them to serotype 46 Australian field isolates of H parasuis. DESIGN: Antisera were produced in rabbits and validated by cross-testing with the reference strains and re-testing 15 Australian field isolates of H parasuis that had been previously serotyped in the United States of America. The validated antisera were then used to determine the serovar of 46 Australian isolates. RESULTS: Monospecific antisera were produced for 14 of the 15 KRG serovars of H parasuis. Two Australian field isolates, confirmed previously as serovars 1 and 7, were used to produce monospecific antisera for serovars 1 and 7 respectively. The antiserum for serovar 4 gave a one-way cross reaction with the antigen of serovar 14. The typing antisera correctly typed all 15 H parasuis that had been previously typed by antisera produced overseas. The 46 field isolates were shown to belong to serovars 2 (two isolates), 4 (one isolate), 5 (18 isolates), 12 (two isolates) and 13 (four isolates). The remaining 19 isolates were non-typable. CONCLUSION: Serotyping of H parasuis isolates is now available in Australia. H parasuis serovars 5 and 13 remain the predominant serovars present in Australian pigs.  相似文献   

Studies on Pasteurella multocida of birds. Third communication: Serological typing of Pasteurella multocida strains isolated from chickens and turkeys     

A H Farid  H A Torky  M M el-Nimr  M Akeula  M Ezzat 《Archiv fuer experimentelle veterinaermedizin》1987,41(2):202-207

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Effects of vitamin E, age and sex on performance of Japanese quail. 1. Haematological indices and liver function     

Elaroussi MA  Fattah MA  Meky NH  Ezzat IE  Wakwak MM 《British poultry science》2007,48(6):669-677

1. A trial was conducted to examine the effects of dietary vitamin E content, age and sex on haematological indices and liver enzymes of Japanese quails. A total of 800 1-d-old quail chicks were assigned at random into 4 equal groups and fed on starter and layer diets containing 0, 1, 5 or 10 times the NRC recommended supplements of vitamin E. No selenium was added to the basal deficient diets; the other diets were supplied with 0.2 mg selenium/kg diet. 2. The investigation covered the age span of 3 to 12 weeks in female and male birds. Blood samples were collected at 3-week intervals and tested for haematological indices (erythrocyte count; leucocyte count; susceptibility of erythrocytes to haemolysis; haemoglobin concentration (Hb); packed cell volume (PCV); and mean corpuscular volume (MCV)) and liver enzymes (aspartate transaminase, AST, and glutathione peroxidase, GSH-Px). 3. The significant differences between the 4 dietary treatments indicated that as the levels of selenium and/or vitamin E increased, the percentage of erythrocytes haemolysed and AST activity decreased, whereas Hb and GSH-Px concentrations increased. 4. Differences between age groups showed that older quails had higher erythrocyte susceptibility to haemolysis, higher AST levels and but lower erythrocyte count and PCV. 5. Females had lower erythrocyte haemolysis and higher Hb concentrations than males. 6. The interaction between dietary groups and age groups revealed that the differences between age groups were reduced as the level of selenium and/or vitamin E increased, leading to similar group means over the age period of study. 7. In conclusion, NRC recommended supplements of vitamin E (12 and 25 mg/kg diet) were not adequate. Doses equal to, at least, 5 times that recommended were advised to improve GSH-Px (index of antioxidant status) and Hb concentrations.  相似文献   

Improvement in wild endangered Persian sturgeon,Acipenser persicus (Borodin, 1897) semen cryopreservation by 2‐hydroxypropyl‐beta‐cyclodextrin (HβCD)          下载免费PDF全文

Ruhollah Rahimi  Hamid Farahmand  Alireza Mirvaghefi  Gholamreza Rafiee  Amirreza Abed Elmdoust 《Aquaculture Research》2015,46(10):2452-2456

In this study, cryopreservation feasibility of Persian sturgeon (Acipenser persicus) and the effect of different doses of 2‐hydroxypropyl‐beta‐cyclodextrin on thawed spermatozoa quality (motility duration and motility percentage) were investigated. For freezing, semen of seven male individuals was pooled in equal volumes and diluted with 4°C [Tris‐HCl (100 mM), pH = 8, DMSO 10%] extenders containing 0, 5, 10, 15 mM of HβCD in a ratio of 1:1(semen/extenders). Then semen was filled into 0.5‐mL straws, and was frozen with vapour of liquid nitrogen at 4‐cm above surface of liquid nitrogen. After 3 min, straws were plunged in to liquid nitrogen. Thawing was performed at 40°C water baths for 15 s. Motility duration of the 10 mM HβCD treated spermatozoa at days 14 (228.98 ± 16.39) and 56 (199.66 ±21.78) were longer than other treatments. In day 56, the motility percentage in treatment with 10 mM was significantly higher (16.14 ± 2.54) (P < 0.05) compared with 5 mM treatment (8.75 ± 2.47) (P < 0.05). Therefore, it is recommended that 10 mM of HβCD can be used as an additive cryoprotectant for increasing cryopreserved spermatozoa quality in this species.  相似文献   

Effects of various sodium adsorption ratio (SAR) mediums on larval performance of the freshwater prawn Macrobrachium rosenbergii (de Man)          下载免费PDF全文

Gholamreza Rafiee  Kamran Rezaei Tavabe  Michael Frinsko  Harry Daniels 《Aquaculture Research》2015,46(3):725-735

The sodium adsorption ratio (SAR) is used to describe the ratio of sodium to calcium and magnesium in water that is very important in both aquaculture and agriculture. SAR treatments including of 20, 30, 40, 50 and 60 were adjusted in 10‐L containers. Initial larval density was fixed at 100 larvae L^?1 and during the culture period, various larval quality parameters were evaluated. Our findings illustrated that at initial stages of larval development, different SAR treatments affected the larval condition index (LCI), but no influences on larval stage index (LSI) were apparent. Importantly, this process at the final larval stages became reversed. In addition, survival at SAR 30 was 12.4% greater than among any other treatments. The highest larval resistance to stress (191 ± 5 ppm), as measured by the 24‐h LC₅₀ formalin test also was observed for SAR 30, at the 11th larval stage. Analysis indicated that calcium absorption during larval developmental stages is affected by SAR levels in the environment and also showed that the optimal SAR treatment was 30 for Macrobrachium rosenbergii larviculture in inland hatchery brackish water. According to our findings and desired SAR for the environment and agricultural soil (<15), effluent of M. rosenbergii inland hatcheries must be treated at least two times by dilution and adding calcium and magnesium salts.  相似文献   

Some physical properties of rough rice (Oryza Sativa L.) grain     

M. Ghasemi Varnamkhasti  H. Mobli  A. Jafari  A.R. Keyhani  M. Heidari Soltanabadi  S. Rafiee  K. Kheiralipour 《Journal of Cereal Science》2008,47(3):496-501

Designing the equipment for processing, sorting, sizing and other post-harvesting equipment of agricultural products requires information about their physical properties. In this study, various physical properties of rough rice cultivars were determined at a moisture content of 10% (wet basis). In the case of Sorkheh cultivar, the average thousand grain weight, equivalent diameter, surface area, volume, sphericity, aspect ratio, true density, bulk density and porosity were 21.64 g, 3.35 mm, 31.76 mm², 20.27 mm³, 39.71%, 0.28, 1269.1 kg/m³, 544.34 kg/m³, and 56.98%, respectively. The corresponding values were 20.52 g, 3.4 mm, 32.58 mm², 21.06 mm³, 39.88%, 0.29, 1193.38 kg/m³, 471.21 kg/m³, and 60.37% for Sazandegi cultivar. For Sorkheh cultivar, the average static coefficient of friction varied from 0.2899 on glass to 0.4349 on plywood, while for Sazandegi cultivar the corresponding value varied from 0.2186 to 0.4279 on the same surfaces. Angle of repose values for Sorkheh and Sazandegi cultivars were 37.66° and 35.83°, respectively. Linear model for describing the mass of rough rice grain was investigated. Mass was estimated with single variable of kernel length with a determination coefficient as 0.862 for Sorkheh cultivar whereas for Sazandegi cultivar was as 0.860.  相似文献   

Role of lipid metabolism through bioremediation of fusaric acid in germinating peanut seedlings     

E.?F.?Abd-AllahEmail author  S.?M.?Ezzat 《Phytoparasitica》2004,32(1):38-42

The effect ofBacillus subtilis on the contents of total lipids, neutral lipids, phospholipids and fatty acids in cotyledonary leaves of peanut (Arachis hypogaea L. cv. ‘Giza 6’) was studied in the presence and absence of the mycotoxin fusaric acid. In experiments conducted in a water culture in test tubes, the amount of total lipids was decreased by fusaric acid and increased byB. subtilis; combined treatment reduced the amount. With respect to the effect of fusaric acid on neutral lipids, a non-significant increase in diacylglycerol, significant decreases in triacylglycerol and sterol, and significant increases in sterol ester and non-esterified fatty acids, were obtained, whereasB. subtilis had the opposite effect. Generally, the amounts of the detected phospholipid fractions and the percentages of unsaturation index as well as fatty acids (palmitic, stearic and oleic) were reduced by fusaric acid. Linoleic acid, on the other hand, showed a reverse response: it was increased by fusaric acid alone or in combination withB. subtilis, the increase in the first case being greater than in the second, whereas linoleic acid disappeared in theB. subtilis treatment. http://www.phytoparasitica.org posting Dec. 16, 2003.  相似文献   

Energy and exergy analyses of the spray drying process of fish oil microencapsulation     

Mortaza Aghbashlo  Hossien Mobli  Shahin Rafiee  Ashkan Madadlou 《Biosystems Engineering》2012,111(2):229-241

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