Download Maisha Djobo BIOL 1615-033 11/01/2011 INTRODUCTION In the

Maisha Djobo
BIOL 1615-033
11/01/2011
INTRODUCTION
In the southern Africa, an infection by the name of feline coronavirus was affecting a
number of animals which include cheetahs, lions, tigers, and sand cats. These animals are
considered nondomestic felids. This infection is classified as being contagious. It was shown in
the US that the feline coronavirus have been mostly found in captive cheetah’s feces and is
detectable in their plasma. “Infection with FCoV has also been detected in captive cheetahs in
Africa” (Heeney et al., 1990). The scientists did this research because outbreaks of feline
infectious peritonitis was occurring a lot in the captive cheetah populations. Also, “they are
known to be highly susceptible to disease following infection with feline coronavirus”
(Evermann, 1986). The hypothesis was that reverse transcription and polymerase chain reaction
was going to detect the feline coronavirus in the fecal samples from nondomestic felids in the
southern Africa.
MATERIAL AND METHODS
A number of experiments were done to test the hypothesis; they included sample
collection, RNA extraction, reverse transcription, and nested polymerase chain reaction, and
finally serology. For the sample selection, feces and blood were obtained from 190 animals from
the Felidae family. The temperature of the samples used were kept under 70 degrees Celsius until
the testing time. One thing the fecal specimen was utilized for is the extraction of Total RNA
with the help of Trizol LS, which is a reagent created to isolate the Total RNA from liquid
samples such as blood.With the help of MMLV RT which stands for Moloney Murine Leukemia
Virus Reverse Transcriptase, the ribonucleic acid was transported to reverse transcription.
Following that, the first strand synthesis occurred with the help of the downstream external
primer. The polymerase chain reaction was useful in this experiment by including an optimized
enzyme by the name of ExTaq polymerase plus the upstream external primer. Then, “this
procedure was followed by nPCR using internal primers” (Kennedy et al., 1998). Serology, the
study of blood serum was performed by using light microscope to track the presence of an
antigen indirectly.
RESULTS
A number of results were pulled from the experiments. 36% of the tested fecal samples
from cheetahs were positive and the other species tested were negative by reverse transcriptase
over the number of polymerase chain reaction for the feline coronavirus. Also, with intervals
ranging from 1-12 mo, ten of 48 animals were positive at multiple time points. When serum was
included in the testing, 84% of cheetahs ended up being seropositive and 30% of other animals
were positive for antibodies to the feline coronavirus.The range of antibodies was from 10 to
320. In conclusion, 57% of the 342 animals tested showed that they were infected with FCoV.
DISCUSSION
The results obtained from this experiment was not just for captive animals, 41 wild
animals may possibly be infected with FCoV. The researchers say that the animals in Namibia
were wild-caught, however the majority of South African cats were involved in captive breeding.
Animals are more in contact with neighbors in South Africa than in Namibia. Apparently, low
antibody levels were kept low by animals who were positive for virus shedding at more than one
time point. “Some animals remained infected for significant periods indicating persistent
infection and virus shedding” (Kennedy et al., 2003). The feline coronavirus of nondomestic
felids has more similarities to FCoV type I than type II. The 7a7b genetic region might be the
cause of coronavirus in domestic cats due to virulence of FCoV association. Changes in genes or
chromosomes may also take place in the 7a7b region. Finally, the feline coronavirus is dominant
in the nondomestic felid populations in the southern Africa.
Works Cited
Heeney, Jonathan L, et al. “Prevalence and implications of feline coronavirus infections of
captive and free-ranging cheetahs (Acinonyx jubatus).” Journal of Virology (1990): 1964-1972
Evermann, James F. “Feline coronavirus infection of cheetahs.” Feline Practice (1986): 21-30
Kennedy, Melissa A, et al. “Correlation of genomic detection of feline coronavirus with various
diagnostic assays for feline infectious peritonitis.” Journal of Veterinary Diagnostic Investigation
(1998): 93-97
Kennedy, Melissa A, et al. “Detection of Feline coronavirus infection in Southern African
nondomestic felids.” Journal of Wildlife Diseases (2003): 529-535