209 RISKS OF TRANSMITTING MYCOBACTERIUM AVIUM SSP. PARATUBERCULOSIS BY TRANSFER OF IN VIVO-DERIVED AND IN VITRO-FERTILIZED BOVINE EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 212
Author(s):  
A. Bielanski ◽  
J. Algire ◽  
G. Randall ◽  
O. Surujballi
Keyword(s):  
Mycobacterium Avium ◽  
Disease Transmission ◽  
Economic Losses ◽  
Persistent Diarrhea ◽  
Bovine Embryos ◽  
Causative Microorganism ◽  
The World ◽  
In Vitro Exposure

Paratuberculosis (Johne's disease) is a chronic infectious disease of cattle and other domestic and wild ruminants caused by Mycobacterium avium ssp. paratuberculosis (Map) which is widespread throughout the world. The disease is characterized by persistent diarrhea, weight loss, and eventually death. In addition to interest in the economic losses, there has been an increasing interest in eradicating the disease due to the potential involvement of the causative microorganism in Crohn's disease, a debilitating chronic enteritis in man. Experiments were conducted to determine the possibility of transmission of Map by embryo transfer (ET) and the association of Map with in vivo-derived and in vitro-fertilized (IVF) embryos. These experiments involved (1) collection of embryos from naturally infected donors (n = 5) and transfer of those embryos to uninfected recipients (n = 12) and testing of others for Map by culture on Herrold's medium with mycobactin or by PCR; and (2) in vitro exposure of in vivo-derived and IVF embryos to Map and their subsequent transfer to uninfected recipients. Experiment 1 revealed the presence of Map in the uterine horns of all five subclinically infected donors, but it was not detected in association with sequentially washed in vivo-derived embryos by culture or by PCR. In Experiment 2, a high proportion of both in vivo-derived and IVF embryos exposed to Map in vitro tested positive for Map even after sequential washings as recommended by IETS. Transfer of in vivo-derived and IVF embryos that had been exposed to Map, and then washed, into 18 recipients resulted in 13 pregnancies and 8 calves born without evidence of disease transmission to either the recipients or the offspring over the following 5 year period. In conclusion, it is unlikely that Map will be transmitted by ET when the embryos have been processed according to the washing protocols recommended by the IETS.

140 INTRAUTERINE INOCULATION OF CATTLE WITH BOVINE VIRAL DIARRHEA VIRUS SIMULTANEOUS TO TRANSFER OF IN VIVO-DERIVED BOVINE EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 169
Author(s):  
J. A. Gard ◽  
M. D. Givens ◽  
P. K. Galik ◽  
M. S. D. Marley ◽  
K. P. Riddell ◽  
...  
Keyword(s):  
Positive Control ◽  
Negative Control ◽  
Bovine Viral Diarrhea ◽  
Bovine Embryos ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
In Vitro Exposure ◽  
Viral Diarrhea Virus

Bovine viral diarrhea virus (BVDV) has been shown to be associated with single transferable in vivo-derived and in vitro-produced bovine embryos despite washing. Hence, the primary objective of this study was to evaluate the potential of BVDV to be transmitted via the intrauterine route at the time of embryo transfer. A total of 10 in vivo-derived Day 7 bovine embryos were nonsurgically collected from a BVDV negative and seronegative donor cow. After collection, embryos were washed in accordance with the International Embryo Transfer Society (IETS) standards. Following washing, embryos were placed into transfer media containing BVDV (SD-1; type 1a). The embryos were immediately aspirated into 0.25-mL straws and transferred into seronegative recipients (Day 0). The total quantity of virus transferred into the uterus of each recipient was 900 to 1000 cell culture infective dose 50 (CCID50)/straw. This amount of virus was previously shown to be consistent with the average amount of BVDV associated with in vivo-derived and in vitro-produced embryos following standard IETS washing procedures after in vitro exposure to virus. The positive control heifer received 1.5 × 106 CCID50/straw of BVDV without an embryo. The negative control heifer received 1.5 × 106 CCID50/straw of heat-inactivated BVDV without an embryo. Serum and buffy coat samples were drawn from all heifers on Days 0, 3, 4, 6, 7, 8, 9, 10, 12, 15, and 30 after inoculation and analyzed for serum neutralizing antibodies and virus, respectively. The positive control heifer and all recipients of virus-exposed embryos exhibited viremia by Day 6 and seroconverted by Day 15. The negative control heifer did not exhibit viremia or seroconvert. All recipients receiving embryos were assessed for pregnancy using transrectal ultrasonography on Day 30 and 6 of 10 heifers were pregnant. On Day 60 the pregnant heifers were again assessed for pregnancy using transrectal ultrasonography. At this time only 1 of the 6 heifers was still pregnant. However, the fetus was determined to be nonviable and was removed via colpotomy. The fetus, fetal fluids and membranes were determined to be positive for BVDV via immunohistochemistry and PCR. Additionally, 213 base pairs of the 5′ nontranslated region of this PCR product were sequenced and found to be consistent with the inoculated strain. Results demonstrate that the average quantity of BVDV associated with bovine embryos after in vitro exposure and washing can result in viremia and seroconversion of seronegative recipients following transfer into the uterus during diestrus.

scholarly journals An investigation into the possibility of bluetongue virus transmission by transfer of infected ovine embryos

2011 ◽  
Vol 78 (1) ◽  
Author(s):  
Estelle H. Venter ◽  
Truuske Gerdes ◽  
Isabel Wright ◽  
Johan Terblanche
Keyword(s):  
Cell Culture ◽  
Bluetongue Virus ◽  
Virus Transmission ◽  
Infected Sheep ◽  
Economic Losses ◽  
Bovine Embryos ◽  
Cell Culture Techniques ◽  
Culture Techniques

Bluetongue (BT), a disease that affects mainly sheep, causes economic losses owing to not only its deleterious effects on animals but also its associated impact on the restriction of movement of livestock and livestock germplasm. The causative agent, bluetongue virus (BTV), can occur in the semen of rams and bulls at the time of peak viraemia and be transferred to a developing foetus. The risk of the transmission of BTV by bovine embryos is negligible if the embryos are washed according to the International Embryo Transfer Society (IETS) protocol. Two experiments were undertaken to determine whether this holds for ovine embryos that had been exposed to BTV. Firstly, the oestrus cycles of 12 ewes were synchronised and the 59 embryos that were obtained were exposed in vitro to BTV-2 and BTV-4 at a dilution of 1 x 102.88 and 1 x 103.5 respectively. In the second experiment, embryos were recovered from sheep at the peak of viraemia. A total of 96 embryos were collected from BTV-infected sheep 21 days after infection. In both experiments half the embryos were washed and treated with trypsin according to the IETS protocol while the remaining embryos were neither washed nor treated. All were tested for the presence of BTV using cell culture techniques. The virus was detected after three passages in BHK-21 cells only in one wash bath in the first experiment and two unwashed embryos exposed to BTV-4 at a titre of 1 x 103.5. No embryos or uterine flush fluids obtained from viraemic donors used in the second experiment were positive for BTV after the standard washing procedure had been followed. The washing procedure of the IETS protocol can thus clear sheep embryos infected with BTV either in vitro or in vivo.

Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

scholarly journals CRISPR/Cas9-based generation of a recombinant double-reporter pseudorabies virus and its characterization in vitro and in vivo

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Peng-Fei Fu ◽  
Xuan Cheng ◽  
Bing-Qian Su ◽  
Li-Fang Duan ◽  
Cong-Rong Wang ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
Fluorescent Protein ◽  
Antiviral Agents ◽  
Firefly Luciferase ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Green Fluorescent ◽  
Swine Herds

AbstractPseudorabies, caused by pseudorabies virus (PRV) variants, has broken out among commercial PRV vaccine-immunized swine herds and resulted in major economic losses to the pig industry in China since late 2011. However, the mechanism of virulence enhancement of variant PRV is currently unclear. Here, a recombinant PRV (rPRV HN1201-EGFP-Luc) with stable expression of enhanced green fluorescent protein (EGFP) and firefly luciferase as a double reporter virus was constructed on the basis of the PRV variant HN1201 through CRISPR/Cas9 gene-editing technology coupled with two sgRNAs. The biological characteristics of the recombinant virus and its lethality to mice were similar to those of the parental strain and displayed a stable viral titre and luciferase activity through 20 passages. Moreover, bioluminescence signals were detected in mice at 12 h after rPRV HN1201-EGFP-Luc infection. Using the double reporter PRV, we also found that 25-hydroxycholesterol had a significant inhibitory effect on PRV both in vivo and in vitro. These results suggested that the double reporter PRV based on PRV variant HN1201 should be an excellent tool for basic virology studies and evaluating antiviral agents.

scholarly journals Aspects of energetic substrate metabolism of in vitro and in vivo bovine embryos

2015 ◽  
Vol 48 (3) ◽  
pp. 191-197 ◽  
Author(s):  
D.K. de Souza ◽  
L.P. Salles ◽  
A.A.M. Rosa e Silva
Keyword(s):  
Bovine Embryos ◽  
Substrate Metabolism
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