Microbiology: Ch. 12

sporangiospore

(Asexual spore) formed within a sporangium, or sac, at the end of an aerial hypha called a sporangiophore.

blastoconidia

(Asexual spores) Another type of conidium, WHAT, consists of buds coming off the parent cell.

arthroconidia

(Asexual spores) Conidia formed by the fragmentation of a septate hypha into single, slightly thickened cells are called WHAT?

chlamydoconidium

(Asexual spores) WHAT is a thick-walled spore formed by rounding and enlargement within a hyphal segment.

yeasts

(Fungi) Unicellular fungi that are typically spherical or oval. Budding yeasts- divide unevenly. Fission yeasts- divide evenly to produce new cells.

cestodes

(Phylum: platyhelminthes) or tapeworms, are intestinal parasites. The head, or scolex, has suckers for attaching to the intestinal mucosa of the definitive host. The body consists of segments called proglottids (repetitive segments). Each mature proglottid contains both male and female reproductive organs. Mature proglottids are essentially bags of eggs, each of which is infective to the proper intermediate host (thousands of eggs)

trophozoite

(Protozoa) The feeding and growing stage, or WHAT (vegetative form), feeds upon bacteria and small particulate nutrients.

subcutaneous mycoses

(fungal disease) WHAT are fungal infections beneath the skin. Caused by saprophytic fungi that live in soil and on vegetation. Acquired by gardeners and farmers. Infection occurs by direct implantation of spores or into a puncture wound in the skin

systemic mycoses

(fungal disease) WHAT are fungal infections deep within the body. Can affect a number of tissues and organs. Caused by fungi that live in the soil. Inhalation of spores is the route of transmission; these infections typically begin in the lungs and then spread to other body tissues.

superficial mycoses

(fungal disease) WHAT are fungi that are localized along hair shafts and in superficial (surface) epidermal cells.

cutaneous mycoses

(fungal disease) WHAT are fungi that infect only the epidermis, hair, and nails. Infection is transmitted from human to human or from animal to human by direct contact or by contact with infected hairs and epidermal cells.

opportunistic mycoses

(fungal disease) WHAT is generally harmless in its normal habitat but can become pathogenic in a host who is seriously traumatized, who is under treatment with broad-spectrum antibiotics, whose immune system is suppressed by drugs or by an immune disorder.

dinoflagellates

(pathogenic algae) WHAT are unicellular algae collectively called plankton, or free-floating organisms. They produce neurotoxins. Toxic marine algae has killed millions of fish, hundreds of marine mammals, and even some humans. When fish swim through large numbers of this, the algae trapped in the gills release a neurotoxin that stops breathing. Large concentrations of this give the ocean a deep red color, from which the name red tide originates.

anamorphs

(phyla of fungi) Produce asexual spores only. Ex.) Penicillium and sporothrix (subcutaneous mycosis). Coccidiodes, Pneumocustis (systemic mycoses- respiratory infections). Candida albicans (cutaneous mycoses) [Growth characteristics: Dimorphic, yeastlike pseudohyphae. Asexual spore types: Conidia, arthroconidia, chlamydoconidia]

basidiomycota

(phyla of fungi) WHAT, or club fungi, also possess septate hyphae. This phylum includes fungi that produce mushrooms. Produce basidiospores and sometimes conidiospores. Cryptococus neoformans (systemic mycosis) [Growth characteristics: Septate hyphae; includes rusts and smuts, and plant pathogens; yeastlike encapsulated cells. Asexual spore type: Conidia]

zygomycota

(phyla of fungi) WHAT, or conjugation fungi, are saprophytic molds that have coenocytic hyphae (hyphae that contain no septa (cross-walls) and appear as long continuous cells with many nuclei). An example is Rhizopus stolonifer, the common black bread mold. Produces sporangiospores and zygospores. [Growth characteristics: nonseptate hyphae, Asexual spore types: sporangiospores, Human pathogens: Rhizopus, Mucor]

ascomycota

(phyla of fungi) WHAT, or sac fungi, include molds with septate hyphae (cross-walls) and some yeasts. Their asexual spores are usually conidia produced in long chains from the conidiophore (a unicellular or multicellular spore that is not enclosed in a sac). Also produce sexual spores called ascospore (results froom the fusion of nuclei of two cells that can be either morphologically similar or dissimilar. These spores are produced in a saclike structure called an ascus. The member of this phylum are called sac fungi because of the ascus. Telemorphic fungi- produces sexual and asexual spores. [Growth characteristics: Dimorphic, Septate hyphae, Asexual spore types: Conidia, Arthroconidia]

archaezoa

(phyla of protozoa) WHAT are eukaryotes that lack mitochondria. They are typically spindle-shaped, with flagella projecting from the front end. Most have two or more flagella. Ex.) Trichomonas vaginalis (human parasite). T. vaginalis does not have a cyst stage and must be transferred from host to host quickly before desiccation occurs. Ex.) #2: Giardia lamblia it is found in the small intestine of mammals. It is excreted in the feces as a cyst and survives in the environment before being ingested by the next host. (water born organism)

apicomplexa

(phyla of protozoa) WHAT are not motile and are obligate intracellular parasites. Have a complex life cycle that involves transmission between several hosts. Ex.) Plasmodium, the causative agent of malaria. Other Ex: Babesia- tick-borne (immune suppressed), cryptosporidium- intestinal disorders (AIDS), cyclospora- diarrhea (rasberries), toxoplasma- toxoplasmosis (cat feces, pregnancy)

microspora

(phyla of protozoa) WHAT like archaezoa, lack mitochondria. They do not have microtubules (non motile) and they are obligate intracellular parasites. This protozoa is the cause of a number of human diseases, including chronic diarrhea and keratoconjuctivitis, most notably in AIDS patience.

amoebozoa

(phyla of protozoa) WHAT move by pseudopods. Ex.) entamoeba histolytica is the only pathogenic amoeba found in human intestine. Ex. #2) Acanthamoeba growing in water, including tap water, can infect the cornea and cause blindness.

cites

(phylum of protozoa) Move by cilia. Complex cells. The cilia move in unison to propel the cell through its environment and to bring food particles to the mouth. The only ciliate that is a human parasite is Balantidium coli, the causative agent of a severe type of dysentery.

Euglenozoa

(phylum of protozoa) Move by flagella. Two groups of flagellated cells are included in this group based on common rRNA sequences, disk-shaped mitochondria, and absence of sexual production. They are chemoheterotrophs. Hemoflagellates (blood parasites) are transmitted by the cites of blood-feeding insects and are found in the circulatory system of the bitten host. Trypanosoma is a species that causes African sleeping sickness.Fatal. Undulating membrane, transmitted by vectors. Naegleria- flagellated and amoeboid forms. Primary amebic meningoene ephalitis. Leishmania- flagellated form in sand fly vector, ovoid form in vertebrate host.

trematodes

(phylum: platyhelminthes (flatworm)) WHAT, or flukes, often have flat, leaf-shaped bodies with a ventral sucker and an oral sucker. Flukes obtain food by absorbing it through their nonliving outercovering called the cuticle. The asian liver fluke clonorchis sinensis. The cercariae of the blood fluke Schistosoma are not ingested. Instead they burrow through the skin of the human host and enter the circulatory system.

Basidiospore

(sexual spore) Formed externally on a pedestal (basidium)

ascospore

(sexual spore) Formed in a sac (ascus)

zygospore

(sexual spore) Fusion of haploid cells produce one WHAT? Large sexual spore enclosed in a thick wall.

sexual spores

A fungal WHAT results from sexual reproduction, which consists of three phases: 1. Plasmogamy: A haploid nucleus of a donor cell (+) penetrates the cytoplasm of a recipient cell (-). 2. Karyogamy: The (+) and (-) nuclei fuse to form a diploid zygote nucleus. 3. Meiosis: The diploid nucleus gives rise to haploid nuclei (sexual spores), some of which may be genetic recombinants.

Arthropods

Animals characterized by segmented bodies, hard external skeletons, and jointed legs. They carry pathogenic microorganisms called VECTORS (meaning they may transmit diseases). Arachnida: 8 legs, spiders. Crustacea: 4 antennae, crabs. Insecta: 6 legs, flies. Some vectors are just a mechanical means of transport for a pathogen. Ex.) Houseflies lay their eggs on feces and pick up pathogen on its feed and transport the pathogen to our food. Or some parasites multiply in their vectors (biological transmission). Definitive host- microbe;s sexual reproduction in vector.

condiospore

Asexual spores are produced by an individual fungus through mitosis and subsequent cell division; there is no fusion of the nuclei of cells. Two types of asexual spores are produced by fungi. One type is WHAT, a unicellular or multicellular spore that is not enclosed in a sac. Condia are produced in a chain at the end of a conidiophore.

apicomplexa

Ex.) Plasmodium- malaria. Mosquito borne (anopheles). P. vivax- most widely distributed. P. falciparum- most virulent. Complex life cycle results in cycles of fever and chills and destruction of RBCs. Highest mortality in young children. Treatment- quinines; vaccine in development

asexual spores

Fungal spores can be either WHAT or sexual. WHAT are formed by the hyphae of one organism. When these spores germinate, they become organisms that are genetically identical to the parent.

sexual spores

Fungal spores can be either asexual or WHAT? WHAT result from the fusion of nuclei from two opposite mating strains of the same species of fungus.

definitive host

Human as WHAT host? The taenia saginata, the beef tapeworm. The feces of an infected human contain mature proglottides, each of which contains thousands of eggs. Upon ingestion by cattle, the larvae hatch from the eggs and bore through the intestinal wall. The larvae migrate to muscle (meat), in which they encyst as cysticerci. When the cysticerci are ingested by humans, all but the scolex is digested. The scolex anchors itself in the small intestine and begins producing proglottids. (Taenia saginata, Cysticerci in beef muscle)

intermediate hosts

Humans as WHAT host? for Echinococcus granulosus. Dogs are coyotes are the definitive host.

helminths

Kingdom: Animalia, Nutritional type: chemoheterotroph, multicellularity: all, cellular arrangement: tissues and organs, food acquisition method: ingestive; absorptive, characteristic features: elaborate life cycles, embryo formation: all

algae

Kingdom: protist, Nutritional Type: photoautotroph (self-feeding), Multicellularity: Some, Cellular arrangement: unicellular, colonial, filamentous; tissues, Food Acquisition method: diffusion, Characteristic features: pigments

protozoa

Kingdom: protist, Nutritional type: Chemoheterotroph, Multicellularity: None, Cellular arrangement: unicellular, Food acquisition method: absorptive; ingestive, Characteristic features: motility; some form cysts

Nematodes eggs infective for humans

Nematodes eggs infective for humans: The pinworm ENTEROBIUS spends its entire life in a human host. The female pinworm migrates to the anus to deposit her eggs on the perianal skin. The eggs can be ingested by the host or by another person exposed through contaminated clothing or bedding. A piece of transparent tape is placed on the perianal skin in such a way where the sticky side picks up eggs that were deposited earlier. ASCARIS is a large nematode with sexual dimorphism- meaning, the male and female worms look distinctly different, the male being smaller with a curled tail for conjugation. The adult ascaris lives in the small intestines of humans exclusively; it feeds primarily on semidigested food (infective beef). Eggs can survive in soil until ingested by another host. The eggs hatch in the small intestine of the host. The larvae then burrow out of the intestine and enter the blood. They are carried to the lungs. The larvae will then be coughed up, swallowed, and returned to the small intestine, where they mature into adults.

Nematodes larvae infective for humans

Nematodes larvae infective for humans: Adult hookworms, NECTOR and ANCYLOSTOMA live in the small intestine of humans. The eggs are excreted in feces. The larvae hatch in the soil. A larva enters its host by penetrating the host's skin. It then enters a blood vessel, which carries it to the lungs. It is coughed up, swallowed, and carried to the small intestine. People can avoid hookworm infections by wearing shoes. TRICHINELLA are usually acquired by eating encysted larvae in poorly cooked pork. Also acquired from eating bears.

fungi

Nutritional type: Chemoheterotroph; Multicellularity: All, except yeasts; Cellular Arrangement: Unicellular, filamentous, fleshy; Food Acquisition Method: Absorptive; Characteristic Features: Sexual and asexual spores; Embryo Formation: None

Nematodes

Phylum: nematoda (roundworms). Roundworms have a complete digestive system, consisting of a mouth, an intestine, and an anus. Bilaterally symmetrical unsegmented worms. Covered by flexible, thick cuticle. Mouth equipped with stylets. Food passes through mouth as result of sucking action of pharynx. Nematode infections of humans can be divided into two categories: those in which the egg is infective, and those in which the larva is infective.

plant pathogens

Phytophthora infestants are responsible for irish potato blight. P. cinnamoni has infected about 20% of one species of Eucalyptus.

Plasmodium life cycle and malaria

Plasmodium life cycle and malaria: 1. When a mosquito (anopheles) carrying the infective stage of plasmodium, called a sporozoite, bites a human, sporozoites can be injected into the human. The sporozites are carried by the blood to the liver 2.) They undergo schizogony in liver cells and produce thousands of progeny called merozoites 3.) Merozoites enter the bloodstream and infect RBC 4.) Merozoite develops into ring stage in RBC 5.) The ring stage enlarges and divides repeatedly 6.) The RBC eventually ruptures and release more merozoites. Merozoites infect new RBC or some develop into male and female sexual forms (gametocytes) 7.) They can be picked up by the bite of another mosquito; they then enter the mosquito's intestine and begin their sexual cycle. 6.) Here the male and female gametocytes unite to form a zygote. The zygote forms an oocyst, in which cell division occurs and asexual sporozoites are formed. 9.) When the oocyst ruptures, the sporozoites migrate to the salivary glands of the mosquito. They can then be injected into a new human host by the biting mosquito.

schizogony

Protozoa reproduce asexually by fission, budding, or WHAT. This is multiple fission; the nucleus undergoes multiple divisions before the cell divides.

conjugation

Sexual reproduction has been observed in some protozoa. The ciliates reproduce sexually by WHAT? During this, two protozoan cells fuse, and a haploid nucleus from each cell migrates to the other cell. This haploid micronucleus fuses with the haploid micronucleus within the cell. The parent cells separate, each now a fertilized cell. When the cells later divide, they produce daughter cells with recombined DNA.

fungal dimorphism

Some fungi, pathogenic species, exhibit WHAT- two forms of growth. Fungi can either grow as a mold or as a yeast. Dimorphism in pathogenic fungi is temperature-denendent at 37 degrees C, the fungus is yeastlike and at 25 decrees C, it is moldlike.

thallus

The WHAT (body) of a mold or fleshy fungus consists of long filaments of cells joined together. These filaments are called hyphae

definitive host, intermediate host

The mosquito is the WHAT because it harbors the sexually reproducing stage of plasmodium. The host in which the parasite undergoes asexual reproduction (human) is the WHAT?

hyphae

The thallus (body) of a mold or fleshy fungus consists of long filaments of cells joined together. These filaments are called WHAT?

cyst

Under certain adverse conditions, some protozoa produce a protective capsule called a WHAT? This permits the organism to survive when food, moisture, or oxygen are lacking, when temperatures are not suitable, or when toxic chemicals are present. This also enables a parasitic species to survive outside a host. (They are hard to kill and can survive harsh conditions like stomach acids)

mycelium

When environmental conditions are suitable, the hyphae grow to form a filamentous mass called a WHAT? (mass of hyphae)

life cycle of trematodes

life cycle of trematodes: The trematode reproduces sexually in a human and asexually in a snail, its first intermediate host. Larvae encysted in the second intermediate host, a crayfish, infect humans when ingested. Life cycle includes definitive host (human) and 2 intermediate host (snail and crayfish)