Cytopathology, plaque assay, and heat inactivation of hepatitis A virus strain HM175

1987 ◽  
Vol 22 (1) ◽  
pp. 35-44 ◽  
Author(s):  
David A. Anderson
2000 ◽  
Vol 63 (4) ◽  
pp. 522-528 ◽  
Author(s):  
S. BIDAWID ◽  
J. M. FARBER ◽  
S. A. SATTAR ◽  
S. HAYWARD

Experiments were performed to determine the thermal resistance of hepatitis A virus (HAV) in three types of dairy products containing increased amounts of fat content (skim milk, homogenized milk; 3.5% MFG, and table cream; 18% MFG). HAV-inoculated dairy products were introduced into custom-made U-shaped microcapillary tubes that in turn were simultaneously immersed in a waterbath, using custom-made floating boats and a carrying platform. Following exposure to the desired time and temperature combinations, the contents of each of the tubes was retrieved and was tested by plaque assay to determine the reduction in virus titer. Our data indicated that <0.5 min at 85°C was sufficient to cause a 5-log reduction in HAV titer in all three dairy products, whereas at 80°C, ≤0.68 min (for skim and homogenized milk), and 1.24 min (for cream) were needed to cause a similar log reduction. Using a nonlinear two-phase negative exponential model (two-compartment model) to analyze the data, it was found that at temperatures of 65, 67, 69, 71, and 75°C, significantly (P < 0.05) higher exposure times were needed to achieve a 1-log reduction in virus titer in cream, as compared to skim and homogenized milk. For example, at 71°C, a significantly (P < 0.05) higher exposure time of 0.52 min (for cream) was needed as compared to ≤0.18 min (for skim and homogenized milk) to achieve a 1-log reduction in virus titer. A similar trend of inactivation was observed at 73 and 75°C where significantly (P < 0.05) higher exposure times of 0.29 to 0.36 min for cream were needed to cause a 1-log reduction in HAV in cream, as compared to ≤0.17 min for skim and homogenized milk. This study has provided information on the heat resistance of HAV in skim milk, homogenized milk, and table cream and demonstrated that an increase in fat content appears to play a protective role and contributes to the heat stability of HAV.


Transfusion ◽  
2013 ◽  
Vol 53 (9) ◽  
pp. 2103-2104 ◽  
Author(s):  
Mikihiro Yunoki ◽  
Kaoru Sakai ◽  
Atsuko Totsuka ◽  
Akemi Wakisaka

2011 ◽  
Vol 3 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Jennifer Harlow ◽  
Denise Oudit ◽  
Ashton Hughes ◽  
Kirsten Mattison

Virology ◽  
1994 ◽  
Vol 204 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Judith Graff ◽  
Christa Kasang ◽  
Andrea Normann ◽  
Mechtild Pfisterer-Hunt ◽  
Stephen M. Feinstone ◽  
...  

2009 ◽  
Vol 72 (11) ◽  
pp. 2390-2393 ◽  
Author(s):  
Y. CAROL SHIEH ◽  
DIANA S. STEWART ◽  
DAVID T. LAIRD

Spinach leaves are frequently consumed raw and have been involved with past foodborne outbreaks. In this study, we examined the survival of hepatitis A virus (HAV) on fresh spinach leaves in moisture- and gas-permeable packages that were stored at 5.4 ± 1.2°C for up to 42 days. Different eluents including phosphate-buffered saline (PBS), pH 7.5 (with and without 2% serum), and 3% beef extract (pH 7.5 and 8) were compared for how efficiently they recovered viruses from spinach by using a simple elution procedure (<1 h). The recoveries were compared and determined by a plaque assay with FRhK-4 cells. Culture grade PBS containing 2% serum was found to be appropriate for HAV elution from spinach leaves, with an average recovery of 45% ± 10%. Over 4 weeks of storage at 5.4 ± 1.2°C, HAV in spinach decreased slightly more than 1 log, with 6.75% of the original titer remaining. HAV survived under refrigerated temperatures on spinach leaves with a D-value of 28.6 days (equivalent to an inactivation rate of 20.035 log of HAV per day, r2 = 0.88). In comparison, HAV in PBS containing 2% serum under the same storage conditions remained constant throughout 7 weeks. The inactivation rate of 20.035 log each day for HAV on spinach leaves was possibly due to the interaction of the virus and the leaf.


1975 ◽  
Vol 148 (2) ◽  
pp. 532-539 ◽  
Author(s):  
P. J. Provost ◽  
B. S. Wolanski ◽  
W. J. Miller ◽  
O. L. Ittensohn ◽  
W. J. McAleer ◽  
...  

1987 ◽  
Vol 22 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Theresa Cromeans ◽  
Mark D. Sobsey ◽  
Howard A. Fields

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