microbiology Acid-fast staining is a method to identify a certain group of bacteria. Acid-fast staining is also called as the Ziehl-Neelsen staining. There are three steps: C: Carbon fuchsin, the primary stain. Put on the specimen and wait for 30 seconds. After that, heat fix the cells by heating A: Acid alcohol, a decolorizer.

microbiology Bacteria are single-celled organisms, which we referred to as prokaryotes that are capable of metabolizing growing and evolving. One very important characteristic about bacteria is that they do not reproduce; they actually undergo a process called binary fission, whereby their cells divide with exact replicas of the DNA of the original cell.

microbiology There are an estimated 1 trillion different species of bacteria on this planet. Approximately 538 of them are known to be human pathogens. The rising concern is the increase in antibiotic resistant bacteria. CDC estimates that more than 2.8 million antibiotic resistant infections occur every year in the US alone.

microbiology Fungi are a kingdom within the eukarya. There are estimated 2.2 million to 3.8 million species of fungi. They are in fact more closely related to animals than plants. Unlike plants, fungi contain chitin in their cell walls, and they do not photosynthesize.

MICROBIOLOGY Parasites are defined as organisms that live on or in a host organism and grow at the expense of the host. Parasitic infections are most common in the tropics and subtropics but can also occur in temperate climates. There are three main classes of human parasites: When looking at the Tree of Life, parasites fall under the category of eukaryote.

Viruses are genetic elements that cannot replicate independently of a living host cell, so they are not technically living organisms. They do possess their own genetic material that encodes various viral particles, but they rely on the host cell for energy metabolic intermediates and actual synthesis of these viral particles and proteins.

MICROBIOLOGY Cestodes are multisegmented, dorsoventrally flattened tape-like worm. Their size varies from from a few milliliters to several meters. The adult worm are found in the small intestines of humans. Cestodes are classified as pseudophyllidean and cyclophyllidean. The body of cestodes is composed of head, which is known as the scolex, the neck, and the trunk.

MICROBIOLOGY Fungi was considered as plant-like organism. However, fungi are more closely related to animal. Fungi are not capable of photosynthesis. Some characteristics of fungi are: Eukaryotes Without chloroplasts but with chitin (N-cetyl-D-glucosamine) Non-photosynthetic With unicellular (yeast) or multicellular (hyphae).

Poxviruses are large and complex viruses that contain many enzymes. These viruses produce eruptive skin pustules called pocks or pox that leave scars. Poxviruses encode proteins that inhibits host immune system defenses. These viruses have double-stranded DNA, "bricked-shaped" virions. They are the largest & most complex animal viruses.

microbiology Neisseria follows these classifications: Neisseria is a gram (-) diplococci that has kidney bean / coffee bean shape. It is oxidase positive in biochemical testing. One of its important features is that it can ferment glucose. There are two pathogenic species of Neisseria : Neisseria gonorrhea is a gram (-) diplococci.

microbiology Pseudomonas aeruginosa is a gram-negative, non-fermentative bacilli that appear in single, in pairs, or in short chains (see the image). Its characteristics are: This bacterium forms smooth round colonies with various greenish color in cultures.

microbiology Bordetella pertussis is a fastidious, aerobe bacterium. It is oxidase and catalase positive. Its virulence factors are: Filamentous hemagglutinin Adenylate cyclase toxin 🡪 impairs leukocytes, inhibiting phagocytosis and causing local edema Tracheal cytotoxin 🡪 interferes ciliary action 🡪 cilia cells die, not able to prevent the bacterium from entering the body Pertussis toxin.

MICROBIOLOGY It follows these taxonomic classifications: The characteristics of streptococcus are as follows: Appear as cocci, chains, in pairs, or single Facultative anaerobes All catalase negative, except for some strains of Enterococcus faecalis . Grows on blood culture. Streptococcus is a normal flora of oropharynx and GIT.

MICROBIOLOGY Staphylococci are 1 m in diameter that appear in single, in pairs, or grape-like clusters-bunch. They are non-motile and non-spore former. They are facultative anaerobic or aerobic, with capsule or slime layer (their pathogenicity factor). The difference of capsule and slime layer is that capsule is attached to the cell wall.

MICROBIOLOGY Gram staining is able to differentiate which bacteria are gram-positive or gram-negative. Here, gram-positive bacilli also mean that they are catalase-positive bacilli. Gram-positive rods are divided into sporeformers and non-sporeformers. Sporeformers are divided into: Non-sporeformers are divided into: Regular shape and staining properties, e.g. Listeria and Erysipelothrix Irregular shape and staining properties.

microbiology Immunity is the body's ability to resist or fight organism or toxins that tend to damage the tissues and joints. The components of the immune system are the skin, leukocytes, antibodies, and other chemical and proteins. Our skin is the largest immunity organ. Our bone marrow produces white blood cells.

microbiology Parasitology: a branch of biology that deals with the phenomenon of dependence of one living organism to another Parasites: organisms depending on another living creature for existence. Parasites is the ones that get the benefit from their hosts. There are several relationships in symbiosis: mutualism, commensalism, or parasitism.

microbiology There are an estimated 1 trillion different species of bacteria on this planet. Scientists estimate there are over 10 to 30 individual cells living on the earth. About 99.9% of those cells are unable to be cultured in the lab, which can make identification of them very difficult.

microbiology Chlamydia bacteria follow these taxonomy classifications: Chlamydia are small, round-to-ovoid obligate intracellular organisms with different stages of replicative cycles (see the image). Chlamydia has ability to turn on and off its apoptotic mechanism in order to stay inside the cell. Chlamydia is the second most common sexually transmitted disease pathogen.

microbiology Viruses can be divided into DNA and RNA virus. RNA virus can be further classified into positive sense and negative sense. Negative sense RNA virus are those whose genetic sequence needs to be converted first mRNA (making it a positive sense). These are enveloped, segmented, ssRNA viruses with helical nucleocapsid.

MICROBIOLOGY Nematodes are said to be the most worm-like of all the helminths. This is because they generally resemble the common earthworm in appearance, which is considered to be the prototype of worms. However, taxonomically speaking, earthworms are not nematodes as they are segmented worms and they are members of the annelids.

microbiology Arthropods are members of the invertebrates, meaning they don't have a skeleton like we humans do. Arthropods consist of fairly wide range of animals, such as insects, crustaceans, arachnids. They are differentiated based on the number of legs Arthropods are also called ectoparasites because they live outside of the body.

MICROBIOLOGY The organism, Candida albicans , is an opportunistic fungus (normally does not cause disease). It can cause disease in elderly and immunocompromised individuals. Candidiasis can be acute, chronic, superficial, or disseminated. Systemic candidiasis is the invasion of internal organs (the most common are pulmonary, renal and meningeal).

microbiology Trematodes are leaf-shaped, unsegmented, flat, and broad helminths. They have large prominent suckers with a hole in the middle (see the image). All trematodes are considered parasitic. They vary in size from 1 mm to several cm. Males trematodes are shorter and stouter than female trematodes.