13-16 Flashcards
live on dead organic matter
saprophytes
causes disease only in a patient whose defense mechanisms against infection have been weaked or compromised
oppotunistic pathogens
distinguishing features of spirochetes
- helical shape
- ability to twist or contort their shape
- occurence of periplasmic flagella
swim best in media of high viscosity
spirochetes
swim best in media of low viscosity
ordinary flagella
Flexible, helical, have periplasmic flagella, saprophytes or parasites
spirochetes
soft and plastic, nonmotile, lack cell walls; parasites and saprophytes
mycoplasmas
bacteria-like forms that are obligate parasites of protozoa, arthropods, or other hosts; have not been isolated or cultivated
endosymbionts
sprirochetes are under the order?
Spirochaetales
2 families of spirochetes
- spirochaetaceae
- leptospiraceae
Characteristics of Spirochaetaceae family
- They are stringent anaerobes, facultative anaerobes, or microaerophiles.
- Carbohydrates or amino acids are used as carbon and energy sources.
characteristics of Leptospiraceae family
- They are aerobes.
- Long-chain fatty acids are used as the carbon and energy source.
AERIOBIC/MICROAEROPHIUC, MOTILE, HELlCAL VIBRIOID, GRAM- NEGATIVE BACTERIA Characeteristics
- The cells are rigid (unlike spirochetes) and range from vibrioid (having less than one turn or twist) to helical (having one to many turns or twists).
- They swim by means of polar flagella.
- They are aerobic or microaerophilic.
- They attack few or no carbohydrates.
- The organisms usually give a positive reaction by the oxidase test (a laboratory test based on the presence of cytochrome c).
Anaerobic and facultatively anaerobic, Use carbohydrates but not amino acids as
carbon and energy sources
Spirochaeta
Harmless parasites of freshwater and marine molluscs, Have never been isolatod; have unusually large number of periplasmic flagella (>100)
Cristispira
Inhabits mouth, intestinal tract, and genital areas of human and animals; some are pathogenic.
Treponema
Anaerobic and microaerophilic; Use carbohydrate and amino acids; sstringents anaerobes harmless parasites
Treponema
Causes hog dysentery
Treponema dysenteriae
Causes syphilis in humans and is microaerophilic
Treponema pallidum
Pathogenic, causes lousebome or tickborne
relapsing fever In humans
Borrelia
Parasites of wild rodents and small mammals, and also of the arthropods associated with these animals
Borrelia
Pathogenic, causes leptospirosis in animals and humans
Leptospira interrogans
Helical or vibrioid organisms that typically possess bipolar tufts
of flagella. These harmless saprophytes are aerobic to microaerophilic and occur in stagnant stream or pond water. No growth occurs in the presence of 3% NaCl or sea water.
Aquaspirilla
The cells are plump and vibrioid with a single polar flagellum and, if grown on solid media, with numerous lateral flagella as well.
Azospirillum
A specie of Azospirillum that can grow autotrophically with hydrogen gas as the energy source.
Azospirillum lipoferum
The cells are helical, usually with bipolar tufts of flagella. Oceanospirilla are aerobic and are harmless saprophytes, occurring in coastal marine waters. Sea water is required for their growth.
Oceanospirillum
These vibrioid cells have a single flagellum at one or both poles microaerophilic parasites, occurring in the reproductive organs, intestinal tract, and oral cavity of humans and other mammals
Campylobacters
h causes diarrhea in human
Campylobacter jejuni
Causes abortion in cattles
Campylobacter fetus venerealis
These aerobic, vibrioid cells possess a single polar flagellum. Have
the unique property of being parasitic on other Gram-negative bacteria.
Bdellovibrio
Has certain similarities with Bdellovibrio, organisms attack eucaryotic algae, not bacteria.
Vampirovibrio
Characteristics of non-motile Gram-negative bacteria
- Rigid cells that are curved to various degrees, forming coils, helical spirals, and sometimes rings (i.e., cells that are curved around so that the ends overlap
- Nonmotile
This section forms one of the largest and most diverse groups of bacteria.
AEROBIC, GRAM.
NEGATIVE RODS AND COCCI