Introduction
One of the families of ssRNA viruses which cause upper respiratory tract diseases in humans and birds is the Coronaviridae family. Although the coronaviruses are known since the early 60s (229 and OC43 viruses), they started attracting attention only since 2003, when a virus causing a severe acute respiratory syndrome (SARS) was discovered in an outbreak that took place in southern China and then spread into several countries.1 Ten years after this event, which was responsible of 774 deaths in over 30 countries (of 8000 confirmed cases), a new “SARS-like” infection emerged from the Middle East and was named as Middle East respiratory syndrome coronavirus (MERS-CoV) by the Coronavirus Study Group of the International Committee for Taxonomy of Viruses. Samples taken from two patients with severe cases of community-acquired pneumonia (Bisha, KSA and Doha, Qatar) contributed to the first isolation of the new virus and its sequencing.2 The novel virus was isolated several other times from locals and tourists of the Arabian Peninsula presenting symptoms which resembled those of the first documented victims of the disease. In retrospect, a group of respiratory infections which took place earlier in Jordan (April 2012) was related to this viral agent.3
The genome analysis of MERS-CoV classified the emerging virus as a member of the lineage C of the genus Betacoronavirus. Interestingly, its closest known relatives are present in bats (HkU-4 and HkU-5). In contrast, it is more distantly related to the SARS-CoV not only genetically, but also in means of the virus receptor usage.3
Virion structure and composition
All coronaviruses have four structural proteins in common (Figure 1): a large surface glycoprotein (S; 1150–1450 ami...
... middle of paper ...
...Lancet Infect. Dis. 9, 291–300 (2009).
10. WHO | MERS-CoV summary updates. WHO at
11. CDC - Coronavirus - Middle East Respiratory Syndrome - MERS-CoV. at
12. Zhou, N., Zhang, Y., Zhang, J.-C., Feng, L. & Bao, J.-K. The receptor binding domain of MERS-CoV: The dawn of vaccine and treatment development. J. Formos. Med. Assoc. 113, 143–147 (2014).
13. Watson, J. T., Hall, A. J., Erdman, D. D., Swerdlow, D. L. & Gerber, S. I. Unraveling the Mysteries of Middle East Respiratory Syndrome Coronavirus. Emerg. Infect. Dis. 20, 1054–1056 (2014).
14. Cavanagh, D. in Princ. Pract. Clin. Virol. (Microbiology, A. J. Z. of M., Virology, J. E. B. E. of C., Pattison, J. R., Virology, P. D. G. of & Director, B. D. S. E.) 379–397 (John Wiley & Sons, Ltd, 2004).
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
[1, 4, 5, 9, 13] There have been no documented cases where a human has contracted the disease from another human. [4] It appears, based on field and lab data, that infection requires direct contact with the virus through means such as contact with infective bodily secretions, urine, or tissues. [12] It is unknown to scientists how the virus can be maintained in the bat populations and avoids extinction as the host species becomes immune to its presence. [14] The incubation period from time of infection to the onset of symptoms is about 5-14 days in experimentally induced animals [4] and 8-14 days in natural field cases.
G. vaginalis cells are gram-negative to gram-variable. These cells are nonmotile, small, pleomorphic rods that do not have endospores, flagella, or typical capsules. In vaginal fluid smears, the Gram reaction may vary from positive to negative (Catlin, 1992). G. vaginalis is viewed in non-crowded areas in a Papanicolaou preparation. Their morphology and staining reactions are affected by the bacteria’s physiological state. Both coccobacilli and longer forms occur in 24 hour cultures of G. vaginalis on blood agar. Their average dimensions are 0.4 by 1.0 to 1.5µm. The cells do not elongate into filaments although they can be up to 2 to 3µm (Catlin, 1992).
Trabelsi, H., Dendana, F., Sellami, A., Sellami, H., Cheikhrouhou, F., Neji, S., … Ayadi, A. (2012). Pathogenic
Chikungunya virus (CHIKV) is a member of the family Togaviridae and genus Alphavirus that have been associated with large sporadic epidemics (Schwartz & Albert, 2010) (Suhrbier, Jaffar-Bandjee, & Gasque, 2012). CHIKV is transmitted to humans by infected mosquitos of the genus Aedes, Aedes aegypti and Aedes albopticus (Torres, et al., 2015). This virus was first identified in 1952 in East Africa and later caused large outbreaks in tropical Asia and Africa (Sissoko, et al., 2009). Chikungunya fever is a re-emerging disease; appearing again in an outbreak in India, 2005, after being silent approximately 32 years (Mohan, Kiran, Manohar, & Kumar, 2010). International travels helps in the introduction of CHIK to different areas. In late 2013, the
We will continue to perform immune-driven escape mutant studies to generate viral escape mutants under the selection of a number of a high affinity, potent neutralizing mAbs that map to different epitopes. The mutant HA genes will be sequenced and the structural changes that resulted in neutralization escape will be determined.
The virus is primarily spherical shaped and roughly 200nm in size, surrounded by a host-cell derived membrane. Its genome is minus-sense single-stranded RNA 16-18 kb in length. It contains matrix protein inside the envelope, hemagglutinin and neuraminidase, fusion protein, nucleocapsid protein, and L and P proteins to form the RNA polymerase. The host-cell receptors on the outside are hemagglutinin and neuraminidase. The virus is allowed to enter the cell when the hemagglutinin/ neuraminidase glycoproteins fuse with the sialic acid on the surface of the host cell, and the capsid enters the cytoplasm. The infected cells express the fusion protein from the virus, and this links the host cells together to create syncitia.
“This knowledge will help us design drugs that mimic the viral effects on these proteins to either activate a host’s immune response or shut it down,” said Dr. Michael Gale, associate ...
A few years before 1918, in the height of the First World War, a calamity occurred that stripped the globe of at least 50 million lives. (Taubenberger, 1918) This calamity was not the death toll of the war; albeit, some individuals may argue the globalization associated with the First World War perpetuated the persistence of this calamity. This calamity was referred to the Spanish Flu of 1918, but calling this devastating pestilence the “Spanish Flu” may be a historical inaccuracy, as research and historians suggest that the likelihood of this disease originating in Spain seams greatly improbable. Despite it’s misnomer, the Spanish Flu, or its virus name H1N1, still swept across the globe passing from human to human by exhaled drops of water that contained a deadly strand of RNA wrapped with a protein casing. Individuals who were unfortunate enough to come in contact with the contents of the protein casing generally developed severe respiratory inflammation, as the Immune system’s own response towards the infected lung cells would destroy much of the lungs, thus causing the lungs to flood with fluids. Due to this flooding, pneumonia was a common cause of death for those infected with Spanish Flu. Due its genetic similarity with Avian Flu, the Spanish Flu is thought to be descended from Avian Flu which is commonly known as “Bird Flu.” (Billings,1997) The Spanish Flu of 1918 has had a larger impact in terms of global significance than any other disease has had because it was the most deadly, easily transmitted across the entire globe, and occurred in an ideal time period for a disease to happen.
Viruses have emerged as causes of foodborne disease, according to data compiled by the Centers for Disease Control and Prevention. Viruses cause a wide range of diseases in plants, animals and humans. These infections do not occur at random: each group of viruses has its own typical host range and cell preference. Viruses were probably always a cause of food borne disease; however with recent developments in detection we are now able to confirm the presence of viruses. Previously, those outbreaks may have been recorded as having an unknown causative agent.
Leboffe, M. J., & Pierce, B. E. (2010). Microbiology: Laboratory Theory and Application, Third Edition 3rd Edition (3rd Ed.). Morton Publishing
World Health Organization “Frequently Asked Questions on Severe Acute Respiratory Syndrome (SARS),” Communicable Disease Surveillance & Response (CSR), March 24. (2003). World Health Organization . Retrieved March 29, 2004.
Dengue virus (DENV) is any of the four serotypes that cause the dengue fever or dengue hemorrhagic fever. It is a single positive-stranded RNA virus belonging to the family of Flaviviridae. Its genome is consisted of 11,000 bases that code for three structural proteins, membrane protein M (prM), envelope protein E, capsid protein C, seven nonstructural proteins NS1-NS5, and a short non-coding region on both the 5’ and 3’ ends 2, 6, 19.
In 1918-19 approximately 50 million deaths were a detriment of the Spanish H1N1 virus pandemic; a respiratory virus. According to the World Health Organization, the second Influenza A H1N1 pandemic in 2009 spread to more than 200 countries causing more than 18 000 deaths. Before the World Health Organization had announced the official end of the pandemic in August 2010, in July 2009 the World Health Organization sent out a phase 6 warning that H1N1 could soon be a global pandemic. It is important to recognize that the 2 different outbreaks had different A/H1N1strains effecting the world population; this suggests A/H1N1has a high ability for mutation, severely complicating the human body’s natural immune mechanism of antigenic drift. (Qi-Shi Du et al., 2010)