Virus Table - Tissue Culture Biologicals

VIRUS TABLE

VIRUS	GENUS	DISEASE	ANIMAL	NUCEIC ACID	ENVELOPE / NON-ENVELOPE	VIRUS SIZE nm	COMMENTS
Transmissible Spongioform Encephalopathy (TSE) (BSE)	Unclassified “Slow Virus”	Mad cow disease Scrapie (sheep)	Bovines, Sheep and Human (compare with CJD and Guru)	Prion Non-Viral			No proven testing methodology for live animals
Bovine viral diarrhea (BVDV)	Flaviviridae (Pestivirus)	Diarrhea	Bovines Sheep 'border disease' Hog cholera	ssRNA	Env.	45-55	Attenuated live viral vaccine Filterable virus at 0.2µ
Parainfluenza virus (PI-3)	Paramyxoviridae	Respiratory	Bovines Sheep	ssRNA	Env.	100-200	Attenuated live virus and inactivated viral vaccines
Bovine herpes virus (BHV)	Herpesviridae/ alpha-herpesviridae	Reproductive/ neonatal	Bovines	dsDNA	Env.	120-200	Attenuated live viral vaccine
Bovine infectious rhinotracheitis (IBR)	Herpesviridae	Respiratory	Bovines	dsDNA	Env.	120-200	Attenuated live viral vaccine
Bovine respiratory syncytial virus	Paramyxoviridae	Respiratory	Bovines	ssRNA	Env.	100-200	Attenuated live viral vaccine
Bovine parvovirus (BPV)	Parvoviridae	Mild systemic	Bovines	ssDNA	Non-Env.	18-26	Filterable virus
Bovine adenovirus (BAV)	Adenoviridae	Pharangeal, lymphoid tissues	Bovines	dsDNA	Non-Env.	70-90
Bovine immunodeficiency virus (BIV)	Retroviridae (Lentivirus)	Leukemia Foamy virus	Bovines	ssRNA	Env.	80-120	No vaccine
Reovirus 3	Reoviridae	Diarrhea	Bovines	dsRNA	Non-Env.	70-80	Attenuated virus vaccine Limited use
Foot and mouth disease virus	Picornaviridae	Respiratory	Bovines Sheep	ssRNA	Non-Env.	20-30	Inactivated virus vaccine available but not normally used
Rabies virus	Rhabdoviridae	Rabies: Encephalitis	All warm-blooded animals are susceptible	ssRNA	Env.	70x170	Vaccination Live attenuated virus
Bluetongue	Reoviridae	Reproductive/ neonatal	Bovines Sheep	dsRNA	Non-Env.	70-80	Mexican and Australian serum test negative to enter USA Attenuated viral vaccine sheep only
Akabane disease	Bunyaviridae	Reproductive neonatal	Bovines	ssRNA	Env.	90-100	Australian serum test negative to enter USA Inactivated viral vaccine
Rinderpest	Paramyxoviridae Morbillivirus	Acute systemic disease	Bovines	ssRNA	Env.	100-200	Attenuated viral vaccine
Bovine coronavirus diarrhea	Coronaviridae	Diarrhea	Bovines	ssRNA	Env.	75-160	Inactivated viral vaccine Limited use
Porcine parvovirus	Parvoviridae	Reproductive/ neonatal	Pigs	ssDNA	Non-Env.	18-26	Inactivated viral vaccine
Equine infectious anemia	Retroviridae	Respiratory/ Acute anemia	Horses	ssRNA	Env.	80-130	No vaccine

ESTABLISHED VIRUS INACTIVATION METHODOLOGIES

GAMMA IRRADIATION (GI)
Aseptically filtered serum is exposed to 2.5 ± 0.3 Rad (25 ± 3 kGrays). Parvovirus is particularly resistant to this level of gamma irradiation exposure, whereas the traditional model viruses BVD, IBR, PI-3 and REO show a 6 log10 clearance, or greater.

HEAT TREATMENT (HI)
Aseptically filtered serum is heated to and maintained at 56°C for 30 minutes to inactivate complement. The enveloped viruses are more heat labile than non-enveloped viruses. Notably bovine syncytial virus (BSV) is also sensitive to repeated freezing and thawing as are other enveloped viruses.

LIPID SOLVENT (LS)
Solvents such as ether or chloroform destroy the infectivity of enveloped viruses.

LOW pH (pH)
Viruses are best preserved in an isotonic environment at physiological pH. Some viruses tolerate a wide ionic and pH range, however, most enveloped viruses are inactivated at pH 5-6. Rotoviruses and many picornaviruses survive the acidic pH of the stomach. Sensitivity to pH is determined by subjecting a virus to a pH of 3.0. Loss of titer greater than one log10, indicates that the virus is pH sensitive and acid labile.

ANTIBODY NEUTRALIZATION (AN)
This method, although inexpensive and effective, is perceived as ‘altering’ the serum.

ASSESSMENT OF INACTIVATION EFFECTIVITY

KEY
++	Extremely Effective
+	Effective
(+)	Less Effective
–	Ineffective

	GI	HI	LS	pH	AN
DNA virus	++	+	–	–	–
RNA virus	++	+	–	–	–
LIPID ENVELOPE	(+)	+	++	+	–
CELL RECEPTORS	(+)	+	++	(+)	–
ANTIGENS	(+)	+	++	(+)	++

FILTRATION
Aseptic filtration has shown to remove the following organisms with these filters:

ORGANISM	FILTER PORE SIZE	COMMENTS
Fungi, bacteria	0.45 Micron	Brevundimonas diminuta, a bacterium which is used for validating 0.2 micron filters will pass through this pore size.
Mycoplasma, Chlamydia, Rickettsia and ‘non-filterable’ viruses (≥ 180 nm)	0.2 Micron	Accepted aseptic filtration pore size.
Virus particles 60-180 nm	0.1 Micron	Multiple filters in series show some reduction of BVD. This filtration pore size has a high retention time.
Virus particles <60 nm	0.04 Micron	Significant reduction of BVD No significant reduction in parvovirus. High retention time.