Risk factors for L. monocytogenes contamination of dairy products in Switzerland, 1990-1999     

Pak SI  Spahr U  Jemmi T  Salman MD 《Preventive veterinary medicine》2002,53(1-2):55-65

Our purpose was to identify the main hazards associated with the spread of Listeria monocytogenes in dairy products in Switzerland and to determine the changes in predominant serotypes of the isolates, using databases on dairy-processing and environments from the Swiss Dairy Research Station during the years 1990-1999. Overall, of 76,271 samples collected, 3722 (4.9%) were positive for the presence of L. monocytogenes. Cheese-ripening facilities had the highest proportion of positive samples (7.6%), followed by small-scale local dairies (4.4%). By sample type, the highest proportion of positive samples (9.5%) was observed in water samples used for cheese-washing, followed by cheese-surface swabs (5.0%). During the 10-year period, no positive samples were obtained from cream, ice cream, milk powder, yogurt, or fresh cheese. Of 3722 L. monocytogenes isolates, 1328 (35.7%) were serologically typeable. Serotypes 1/2a, 1/2b, and 4b accounted for 92.7% of the 1328 isolates. Until 1995, the most-prevalent serotype was 1/2b (annual proportional prevalence 39.3-72.2%)--whereas since 1996, 1/2a was the most prevalent (34.7-54.7%). During 1996-1999, serotype 1/2a increased by 88%, compared to the average of 1990-1995. In the final random-effect multivariable logistic model, the strongest predictor of a positive culture was samples from cheese-ripening plant (OR=1.54; 95% CI: 1.14, 2.08) and the second-strongest predictor was samples collected by someone who was employed by the plant (OR=1.48; 1.29, 1.71). Hard and semi-hard cheeses were more likely to be associated with serotype 1/2b and soft cheeses with serotype 1/2a.  相似文献   

Prevalence and risk factors for contamination with Listeria monocytogenes of imported and exported meat and fish products in Switzerland, 1992-2000     

Jemmi T  Pak SI  Salman MD 《Preventive veterinary medicine》2002,54(1):25-36

A total of 2053 import and 164 export samples from 425 production plants were examined over a 9-year period (1992-2000) for the presence of Listeria monocytogenes (L. monocytogenes) in Switzerland. Overall, 282 samples (12.2%) and 85 plants (20.5%) harbored the pathogen. The highest isolation risk was for marinated fish (38%); the lowest was in cured- and dried-meat products.Unconditional fixed-effect logistic regression was used to identify the main hazards associated with the presence of L. monocytogenes. The plant-level model considered potential risk factors for a positive culture operating at the production-plant level by including a random effect of plant and year.Food category was the only significant factor; sampling site, country of origin and season were not significant. Marinated fish was a strong predictor for positive culture, whereas cooked- and cured-meat products were protective. Plant and year effects were significant. Control measures should be focused on specific food items in each production plant.  相似文献   

Genetic analysis of vesicular stomatitis virus-New Jersey from the 1995 outbreak in the western United States     

Llewellyn ZN  Ou X  Chang GJ  Schmitt B  Salman MD  Akkina RK 《American journal of veterinary research》2000,61(11):1358-1363

OBJECTIVE: To compare molecular associations between the vesicular stomatitis virus (VSV)-New Jersey isolates of the 1995 outbreak with those from previous outbreaks between 1982 and 1985 in the western United States. SAMPLE POPULATION: 23 virus isolates considered representative of the 1995 outbreak of vesicular stomatitis. PROCEDURE: Viral gene coding for surface-envelope protein G was evaluated by use of nucleotide sequencing and phylogenetic analysis. RESULTS: Changes in up to 0.77% of the nucleotide bases and 1.35% of the amino acids were detected among the 1995 viral isolates, whereas changes in up to 3.2 and 2.9% of the nucleotides and amino acids, respectively, were found, compared with the 1982 to 1985 viruses. Insertions or deletions were not found in the entire gene, which spanned 1,554 nucleotide bases. CONCLUSIONS AND CLINICAL RELEVANCE: Phylogenetic analysis indicated that the 1995 VSV-New Jersey belongs to a lineage distinct from that of the 1982 to 1985 viruses that caused previous outbreaks in the western United States. Furthermore, it also is distinct from strains from Central America and from the Georgian Hazelhurst strain.  相似文献   

Other ways to interpret results from heartworm infection study     

Salman MD  Gardner IA 《Journal of the American Veterinary Medical Association》2000,217(12):1789

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Assessment of a bovine viral diarrhea virus antigen capture ELISA and a microtiter virus isolation ELISA using pooled ear notch and serum samples.     

Susan M Cleveland  M D Salman  Hana Van Campen 《Journal of veterinary diagnostic investigation》2006,18(4):395-398

To reduce the cost of whole herd screening for bovine viral diarrhea virus persistently infected animals, the sensitivity and specificity of an antigen-capture enzyme-linked immunosorbent assay (AC-ELISA) and a microtiter virus isolation ELISA using saline from ear notch samples or pooled serum was determined. Pooled saline from ear notch samples, assayed by AC-ELISA, gave a sensitivity and specificity of 98% and 94%, respectively, for pools containing 2 samples and 72% and 100%, respectively, for pools of 5. The sensitivity of pooled ear notch or serum samples for bovine viral diarrhea virus detection by microtiter virus isolation (sensitivity < 5%) or serum samples for detection by AC-ELISA (sensitivity < 15%) is too low to be used for whole herd screening. Pooling saline from ear notch samples from 2 animals tested by AC-ELISA, however, could provide a less expensive, reliable method for whole herd screening for bovine viral diarrhea virus.  相似文献   

Eperythrozoon wenyonii infection in dairy cattle   总被引：1，自引：0，他引：1  

J A Smith  M A Thrall  J L Smith  M D Salman  S V Ching  J K Collins 《Journal of the American Veterinary Medical Association》1990,196(8):1244-1250

Approximately 10 of 100 young heifers that had recently delivered their first calf--members of a large Colorado dairy herd--had a syndrome of swollen teats and distal portions of the hind limbs, prefemoral lymphadenopathy, transient fever, rough coat, decreased milk production, and subsequent weight loss and reproductive inefficiency. Acute clinical signs of disease were associated with large numbers of Eperythrozoon wenyonii seen on blood smears, and resolution of signs correlated with reduction or disappearance of the parasite. Other known causes of peripheral edema could not be documented. The parasite was transmitted to 4 of 7 nonlactating dairy cows destined to be culled and a splenectomized calf via IV inoculation of blood from parasitemic heifers, but clinical signs of infection were not induced.  相似文献   

Zur Populationadynamik und Aktivitätszeit der echten Spinnen (Araneida) auf Kleefeldern in Ägypten     

A. A. Negm  M. F. Abou-Ghadir  A. G. A. Salman 《Journal of pest science》1975,48(11):161-163

Population trend and time of activity of certain true spiders (Araneida), collected from clover foliage in Egypt A general survey of spider populations in a clover field at Assiut, Egypt, using the insect sweep net, revealed that their populations underwent violent oscillations throughout the growing season. However, number of spiders increased progressively and reached their peak late in May. The Salticidae, Tetragnathidae, and Thomisidae were the predominant families. They were amounted to 32, 23, 20 per cent of the total number of specimens collected during this study, respectively. The Clubionidae, Linyphiidae, and Lycosidae were collected in fewer numbers than the first three families. Data showed a possible occurrence of seasonal and temporal succession in the activity as well as relative population density of the studied spider families. Their maximum period of activity centered around Noon especially during January and February. However, this period was shifted to 8: AM and/or 8: PM during April and May.  相似文献   

Inhibition on human liver cytochrome P450 3A4 by constituents of fennel (Foeniculum vulgare): identification and characterization of a mechanism-based inactivator     

Subehan  Zaidi SF  Kadota S  Tezuka Y 《Journal of agricultural and food chemistry》2007,55(25):10162-10167

Fennel, a seed of Foeniculum vulgare, is used as a culinary spice and traditional medicine. The methanolic extract of fennel showed a characteristic of mechanism-based inactivation on erythromycin N-demethylation mediated by human liver microsomal cytochrome P450 3A4 (CYP3A4). The present study was conducted to identify the fennel constituent having the inhibition. Thirteen compounds have been isolated from a methanol extract of fennel and tested for their inhibition on CYP3A4. Among them, 5-methoxypsoralen (5-MOP) showed the strongest inhibition with an IC50 value of 18.3 microM and a mixed type of inhibition. In addition, with the preincubation time of 20 min only 5-MOP showed preincubation time dependency; the IC50 value decreased from 18.3 microM with a preincubation time of 0 min to 4.6 microM with a preincubation time of 20 min. Further investigation on 5-MOP showed the characteristics of time-dependent inhibition, requirement of NADPH, lack of protecting effect of nucleophiles, and recovery of CYP3A4 activity by the competitive inhibitor. This result suggests that the inhibitory activity of CYP3A4 by 5-MOP was a mechanism-based inactivation. The kinetic parameter for mechanism-based inactivation was characterized by a KI value of 15.0 microM and a kinact value of 0.098 min(-1).  相似文献   

Versatile physiological functions of the Nudix hydrolase family in berry development and stress response in grapevine          下载免费PDF全文

WANG Pei-pei  WANG Zhao-ke  GUAN Le  Muhammad Salman HAIDER  Maazullah NASIM  YUAN Yong-bing  LIU Geng-sen  LENG Xiang-peng 《农业科学学报》2022,21(1):91-112

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Understanding the economic and farming practices driving species selection in aquaculture within the Mymensingh division of Bangladesh     

Heal  Richard  Haque  Mohammad Mahfujul  Hasan  Neaz A.  Nagoli  Joseph  Arifuzzaman  Syed  Tyler  Charles R.  Bass  David 《Aquaculture International》2022,30(2):773-789

Aquaculture is a major supplier of animal protein for Bangladesh’s population, and the Mymensingh division is a major contributor to finfish aquaculture, producing 43% of the total pond pangasius and 9% of the total amount of tilapia (figures from 2018). We conducted a finfish farmer survey covering Netrokona, Jamalpur and Mymensingh districts to understand current finfish farming practices and identify factors that drive farmers in their species choice between pangasius or tilapia cultivation. We found that most finfish farmers in Mymensingh are experienced practitioners and practise polyculture with a range of stocking densities for each species. Using an economic model of polyculture practice, we have shown that over a production cycle, pangasius gain body mass at a rate nearly 4 times greater than that for tilapia, resulting in substantially larger revenues and providing a strong incentive for their culture. High levels of tilapia aquaculture likely persist due to their short production cycle and an associated decreased economic risk due to crop loss from disease, both factors providing a strong incentive for their culture. Our findings also indicate production yield differences through different species selection in polyculture systems. For example, co-culturing pangasius, tilapia and carp together was less productive than co-culture of pangasius with tilapia. Furthermore, higher yields of tilapia were obtained when co-cultured with carp compared with pangasius, the reasons for which are not known and warrant further investigation. Our study uses information provided by finfish farmers to produce a useful guide on fish species choices to maximise production yields, and therefore food production, from their ponds.

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