Proper collection of specimens is of utmost importance to avoid contamination of the collected specimen with normal microbial flora and prompt transport to the laboratory for processing is very essential for the diagnosis of infectious diseases. Isolation of anaerobes from clinical specimens, determination of the numbers of anaerobes in the specimen, and establishing the clinical […]
In order to cause infection, a successful pathogen must be able to: Enter and establish in the human host Acquire nutrients from the host Avoid or circumvent the host’s innate defenses and a powerful immune system Multiply in numbers Disseminate to a preferred site, if necessary and eventually Be transmitted to a new susceptible host […]
What is Ebola? Ebola, previously known as Ebola hemorrhagic fever, is a severe, most often fatal disease in humans and nonhuman primates. Ebola is a rare and deadly disease caused by infection with a virus of the family Filoviridae, genus Ebolavirus. These are filamentous, enveloped particles with a single stranded RNA genome( approx. 19 kb […]
Classification Kingdom: Bacteria Phylum: Proteobacteria Class: Gamma Proteobacteria Order: Enterobacteriales Family: Enterobacteriaceae Genus: Shigella Type species: S. dysenteriae Definition of Shigella: They are fermentative, facultative anaerobic non spore forming gram negative bacilli, non motile, catalase positive (except Shigella dysentriae type 1), oxidase negative, do not produce gas form carbohydrates with few exceptions. None forms […]
Shigella is a common cause of bacterial diarrhoea worldwide, especially in developing countries. Humans are the only natural reservoir for disease. Transmission can occur via direct person-to-person spread, as well as via contaminated food and water. Infective dose is very low as 10-100 bacilli can cause disease. Once ingested, the bacteria survive the gastric environment […]
Voges-Proskauer test is one of the tests used for identification of Enterobacteriaceae. It is usually performed alongside the methyl red test since both tests are performed on cultures grown in MR-VP broth. Both tests are based on the detection of end products from the metabolism of glucose. VP test is based on the detection of […]
Oxidative/Fermentative (O/F) test is done to distinguish between aerobes and anaerobes through their ability to breakdown carbohydrates. In this test, a semi solid medium containing a carbohydrate (usually glucose) and a pH indicator is used. If acid is produced only at the surface of the medium, where conditions are aerobic, the attack on sugar is […]