Gram Negatives
Burkholderia cepacia complex
Associated with patients with cystic fibrosis. Environmental species found in soil and water Not part of the human normal flora Can cause disease in plants/humans "dirt like" odor extremely important in cystic fibrosis patients (adheres to mucin)
Brucella abortus
Bang's disease, zoonosis from cattle, spontaneous abortions in cattle, undulant fever
Chlamydial reproduction
Begins with attachment of an EB to host cell Host cell phagocytizes the EB, but fusion of lysosome with the phagosome is prevented by the EB EB reorganizes itself into a reticulate body (RB), which is specialized for reproduction RB reproduces repeatedly, giving rise to many RBs, all within a vacuole RBs change back into EBs, and these are released when the host lyses
Gram-negative aerobic rods (coccobacilli)
Bordetella pertussis Legionella pneumophila Haemophilus influenzae Brucella abortus *Franciella tularensis* *Pasteurella multocida*
Phylum Chlorobi
Green sulfur bacteria
The 2nd edition of Bergey's Manual divides the photosynthetic bacteria into six groups:
Phylum Chloroflexi-green nonsulfur bacteria Phylum Chlorobi-green sulfur bacteria Phylum Cyanobacteria Phylum Proteobacteria-Purple sulfur bacteria (gammaproteobacteria) and purple nonsulfur bacteria (alphaproteobacteria and betaproteobacteria)
Successful at establishing symbiotic relationships
(e.g., in lichens; symbionts with protozoa, fungi and plants)
Escherichia coli (E. coli)
A common bacterium found in the gut of warm-blooded animals. Most strains are harmless, including the strain used in these lab protocols.
Neisseria meningitides
A form of bacterial meningitis characterized by rapid onset of symptoms, often leading to shock and death.
Rhizobium leguminosarum
a Gram negative rod shaped bacterium that forms a nitrogen-fixing symbiosis in root nodules of legume plants such as peas, clover and beans
Salmonella
a bacterium that occurs mainly in the intestine, especially a serotype causing food poisoning.
C. pneumoniae
a causative agent of human pneumonia and possibly atherosclerosis and heart disease
Prochlorothrix
free living
Campylobacter jejuni
gastroenteritis
Salmonella enterica
gastroenteritis
green bacteria
gram negative photosynthetic bacteria, sulfur bacteria (photoautotrophich) found in hot springs, nonsulfur bacteria (photoheterotrophic) usually found in marine a high salt environments
Phylum Proteobacteria
gram-negative cell walls
green sulfur bacteria
gram-negative, nonproteobacteria; strictly anaerobic and phototrophic; no growth in dark; use reduced sulfur compounds as electron donors for CO2 fixation
Phylum Chloroflexi
green nonsulfur bacteria
purple nonsulfur bacteria
Alphaproteobacteria; strictly anaerobic and phototrophic; grow on yeast extract in dark; use reduced organic compounds as electron donors for CO2 fixation
purple bacteria
Anoxygenic phototrophs, gram -, true bacteria, can be purple/red/orange; photosynthesis occurs in the cell membrane and can have purple sulfur bacteria
Three recognized human pathogens
C. trachomatis-trachoma, C. psittaci, C. pneumoniae
Relatively little is known about the biology of deinococci
Can be isolated from ground meat, feces, air, fresh water, and other sources but their natural habitat is not known Genome consists of two circular chromosomes, a mega plasmid, and a small plasmid Have an unusual ability to repair chromosomal damage (even fragmentation) and this probably accounts for their ability to resist desiccation and radiation; genomic analysis show they have many DNA repair genes and many repeat sequences
Salmonella typhi
Causes typhoid fever: diarrhea, HA, rose spots on abdomen. Can remain in gallbladder chronically.
Neisseria gonorrhoeae
Ceftriaxone (add doxycycline to cover likely concurrent Chlamydia)
Phylum Bacteroidetes
Consists of 50 genera divided into 3 classes (Bacteroides, Flavobacteria, and Shpingobacteria)
Order Enterobacteriales
Consists of one family containing over 41 genera; all are gram-negative, peritrichously flagellated or nonmotile, facultatively anaerobic, straight rods with simple nutritional requirements Their metabolic properties are useful for characterization and identification Degrade sugars by Embden-Meyerhof pathway and cleave pyruvic acid into formic acid in formic acid fermentations The majority (e.g., Escherichia, Proteus, Salmonella and Shigella) carries out mixed acid fermentation, while others (e.g., Enterobacter, Serratia, Erwinia and Klebsiella) carry out butanediol fermentation Usually are identified using rapid commercial identification systems (e.g., Enterotube, API 20-E) that are based on these biochemical characteristics Are very common, widespread, and important Escherichia coli is probably the best-studied bacterium and experimental organism of choice for many microbiologists; it is an intestinal tract inhabitant and an indicator organism for water quality (fecal contamination) Salmonella enteritica subspecies typhi-typhoid fever and gastroenteritis. Normal microbiota of reptiles and birds. They cause illnesses like typhoid fever, paratyphoid fever, and foodborne illness. Most species produce hydrogen sulfide Shigella dysenteriae -bacillary dysentery Klebsiella pneumoniae-pneumonia Yersinia pestis-plague Erwinia-plant pathogens
Deinococcus-Thermus
Consists of three genera; genus Deinococcus is the best studied Spherical or rod-shaped; often associated in pairs or tetrads Aerobic, mesophilic, catalase positive, and usually able to produce acid from only a few sugars They stain gram-positive but have a layered cell wall and an outer membrane like gram-negative bacteria; have L-ornithine in their peptidoglycan and lack teichoic acid Have a plasma membrane with large amounts of palmitoleic acid rather than phosphatidylglycerol phospholipids Extraordinarily resistant to desiccation and radiation
Phylum Planctomycetes
Contains one class, one order, and four genera Spherical or oval, budding bacteria with distinctive crateriform structures (pits) in their walls In two genera, Gemmata and Pirullela, the nuclear body is membrane bounded, something that is not seen in other procaryotes The genus Planctomyces attaches to surfaces through a stalk and holdfast; other genera lack stalks Most have life cycles in which sessile cells bud to produce motile swarmer cells
Order Vibrionales
Contains only one family, Vibrionaceae Are gram-negative, straight or curved rods with polar flagella Are oxidase-positive and use D-glucose as their sole or primary carbon and energy source Are aquatic with widespread distribution in freshwater and marine habitats Contains six genera: Vibrio, Photobacterium, Enhydrobacter, Salinivibrio, Listonella, and Allomonas Pathogens in this order include V. cholerae (cholera), V. parahaemolyticus (gastroenteritis after eating contaminated seafood), and V. anguillarum (a fish pathogen) Some (e.g., V. fischeri and at least two species of Photobacterium) are among the few marine bacteria capable of bioluminescence; some bioluminescent species live symbiotically in the luminous organs of fish while others are free-living
Order Methylococcales
Contains rods, vibrios, and cocci that use methane and methanol as their sole carbon and energy source (methylotrophs) under aerobic or microaerobic conditions; among the six genera are Methylococcus (spherical, nonmotile) and Methylomonas (straight, curved, or branched rods with a single polar flagellum) When oxidizing methane have complex arrays of intracellular membranes Found in anaerobic habitats, where methane is often abundant Use methane as source of both energy and carbon Methane is oxidized to methanol and then to formaldehyde Formaldehyde is then assimilated into cell material
Family Rhizobiaceae
Contains the gram-negative genera Rhizobium and Agrobacterium Genus Rhizobium Motile rods (often containing poly-b-hydroxybutyrate granules) that become pleomorphic under adverse conditions Rhizobium leguminosarum Grow symbiotically within root nodules cells of legumes as nitrogen-fixing bacteroids Genus Agrobacterium Not capable of nitrogen fixation Invades crown, roots, and stems of many plants and transforms infected plant cells into autonomously proliferating tumors A. tumefaciens (best studied) causes crown gall disease by means of a tumor inducing (Ti) plasmid
Chlamydia trachomatis
Doxycycline (+ ceftriaxone for gonorrhea coinfection), erythromycin eye drops (prophylaxis in infants)
Order Burkholderiales-contains five families, three of them with well-known genera
Family Burkholderiaceae-contains the genus Burkholderia (described below) Gram-negative, aerobic, nonfermentative, non-spore-forming, mesophilic, straight rods; all but one species are motile with a single flagellum or a tuft of polar flagella Catalase-positive and often oxidase-positive; use poly-b-hydroxybutyrate as their carbon reserve B. cepacia is very active in recycling organic materials; is a plant pathogen; can cause disease in hospital patients due to contaminated equipment and medications; a particular problem with cystic fibrosis patients Family Alcaliginaceae-contains the genus Bordetella (described below) Gram-negative, aerobic coccobacilli Chemoorganotrophs with respiratory metabolism; require organic sulfur and nitrogen (in the form of amino acids) for growth Mammalian parasites that multiply in respiratory epithelial cells B. pertussis-nonmotile, encapsulated species that is the causative agent for whooping cough Family Comamonadaceae-contains 15 genera with diverse characteristics Some (e.g., Sphaerotilus and Leptothrix) have a sheath, a hollow tubelike structure surrounding a chain of cells, which helps bacteria attach to surfaces and obtain nutrients from slowly running water as it flows past; sheath also provides protection against predators Members of the genus Sphaerotilus form long sheathed chains of rods, often attach to solid surfaces by a holdfast, reproduce and spread via swarmer cells, prefer slowly running freshwater polluted with sewage or industrial waste, and can form tangled masses that interfere with activated sludge tanks used in sewage treatment Members of the genus Leptothrix deposit large amounts of iron and manganese oxides in the sheath; this provides protection and allows growth in the presence of high concentrations of soluble iron compounds
Phylum Chloroflexi-green nonsulfur bacteria
Genus Chloroflexus-major representative of the photosynthetic green nonsulfur bacteria Filamentous, gliding bacteria Thermophilic, often isolated from neutral to alkaline hot springs where they grow in the form of orange-reddish mats Ultrastructure and photosynthetic pigments are like green bacteria, but their metabolism is similar to that of the purple nonsulfur bacteria Can carry out anoxygenic photosynthesis with organic compounds as carbon sources or can grow aerobically as a chemoheterotroph Genus Herpetosiphon-represents nonphotosynthetic members of phylum Chloroflexi; contains gliding, rod-shaped filamentous bacteria; aerobic chemoorganotrophs with respiratory metabolism; isolated from fresh water and soil
Bordetella pertussis (whooping cough)
Gram neg. coccobacilli. mild cases are common with persistant cough that is commonly misdiagnosed as bronchitis. serve cases have pneumonia, convulsions, bacteremia, brain inflammation, possible dealth due to cyanosis, serve cough and vomiting. those indivduals are susceptible to secondary infections
Phylum Spirochaetes
Gram-negative, chemoheterotrophic, flexibly helical bacteria that exhibit a creeping (crawling) motility due to a structure called an axial filament The axial filament (a complex of periplasmic flagella) lies in a flexible outer sheath (outer membrane) outside the protoplasmic cylinder, which houses the nucleoid and cytoplasm; function of the sheath is essential (spirochetes will die if it is removed) but unknown Flagellar rotation is responsible for motility by an unknown mechanism, presumably by rotating the outer sheath or flexing the cell for a crawling motion. Can be anaerobic, facultatively anaerobic, or aerobic and can use a diverse array of organic molecules as carbon and energy sources
The Caulobacteraceae and Hyphomicrobiaceae
Have one of three distinguishing features Prostheca-an extension of the cell, including the plasma membrane, that is narrower than the mature cell Stalk-a nonliving appendage produced by cells and extending from it Reproduction by budding-parental cell retains its identity and progeny are much smaller than the parental cell Genus Hyphomicrobium-chemoheterotrophic, aerobic, budding bacteria that frequently attach to solid objects in freshwater, marine and terrestrial environments During budding process, mature cell produces a hypha or prostheca that elongates; the nucleoid divides and a copy moves into the hypha while a bud forms at its end; the bud matures, produces one to three flagella, and a septum divides the bud from the hypha; the bud is released as an oval- to pear-shaped swarmer cell Has distinctive nutrition and physiology-grows on ethanol, acetate and one-carbon molecules such as methanol, formate, and formaldehyde (i.e., it is a facultative methylotroph) May be as much as 25% of the total bacterial population in oligotrophic or nutrient-poor freshwater habitats Genus Caulobacter May be polarly flagellated rods or may possess prostheca and holdfast, by which they attach to solid substrata Usually found in low-nutrient freshwater and marine habitats, but also present in soil; often adhere to bacteria, algae, and other microorganisms and may absorb nutrients released by their hosts Prostheca differs from that of Hyphomicrobium in that it lacks cytoplasmic components and is composed almost totally of plasma membrane and cell wall Reproduction involves formation of a single flagellum at the end opposite the prostheca; asymmetric transverse fission forms a swarmer cell that swims off; when the swarmer comes to rest, it forms a new prostheca at the flagellar end and loses the flagellum, and begins to form swarmers; whole cycle takes only 2 hours
Spirillum
Helicobacter pylori (urease positive) Campylobacter jejuni (urease negative)
Primarily gastrointestinal problems
Helicobacter pylori, Salmonella enteritidis Salmonella typhi
Class Alphaproteobacteria
Includes most of the oligotrophic proteobacteria The Purple Nonsulfur Bacteria Like all purple bacteria, the purple nonsulfur bacteria use anoxygenic photosynthesis, possess bacteriochlorophylls a or b, have their photosystems in membranes that are continuous with the plasma membrane, and are usually motile by polar flagella; with one exception, all purple nonsulfur bacteria are alphproteobacteria Flexible in their choice of an energy source; normally they are grown anaerobically as photoorganoheterotophs, but can grow aerobically as chemoorganotrophs, and some can carry out fermentations May be spirals, rods; some form prosthecae and buds They are found in the mud and water of lakes and ponds with abundant organic matter and low sulfide levels; some marine species are known
Order Nitrosomonadales
Includes the nitrifying bacteria Nitrosomonas, Nitrosococcus, and Nitrosospira, discussed earlier Also includes the genera Gallionella (a stalked chemolithotroph) and Spirillum
Enterics aka Gram-negative fa (i.e. facultatively anaerobic) rods (bacilli) Note: these are also glucose/lactose positive
Klebsiella Escherichia Enterobacter ↑These three are fast fermenters Serratia Citrobacter ↑And others are slow fermenters Salmonella enteric (motile, urease negative & H2S prod.) Salmonella typhi (motile, urease negative & H2S prod.) Shigella dysenteriae (non-motile & urease negative) ↑These three are non-coliform enteric pathogens Proteus mirabilis (urease positive) Yersinia entercolitica (urease negative) Yersinia pestis *Erwinia* ↑These three are similar enough to be included with enteric even though most spp. do not inhabit the gut
Bacteria: The Proteobacteria
Largest and most diverse group of bacteria Divided into five classes: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, and Epsilonproteobacteria The observation that purple photosynthetic bacteria are scattered throughout this phylum has led to the proposal that the proteobacteria arose from a photosynthetic ancestor
Phylum Cyanobacteria
Largest and most diverse group of photosynthetic bacteria (56 genera are described in the 2nd edition of Bergey's Manual) Photosynthetic system resembles that of eucaryotes, having chlorophyll a and photosystem II; carry out oxygenic photosynthesis Photosynthetic pigments are in thylakoid membranes lined with particles called phycobilisomes (contain phycobilin pigments), which transfer energy to photosystem II; some species are red-brown and contain the pigment phycoerythrin Fix carbon dioxide by the Calvin cycle Do not have functional TCA cycle; pentose phosphate pathway plays a central role in their metabolism Although they are oxygenic photolithoautotrophs, some can grow slowly in the dark as chemoheterotrophs, and some species can carry out anoxygenic photosynthesis if in an anaerobic environment Vary greatly in shape and appearance May be unicellular, exist as colonies of many shapes, or form filaments called trichomes (rows of bacterial cells that are in close contact with one another over a large area) Have typical procaryotic structures with a gram-negative cell wall Often use gas vesicles to move vertically in the water; many filamentous cyanobacteria have a gliding motility; although cyanobacteria lack flagella, some marine species are able to move by an unknown mechanism Reproduce by binary fission, budding, fragmentation, and multiple fission Fragmentation generates small motile filaments called hormogonia Some species develop akinetes, which are thick-walled resting cells that are resistant to desiccation; these often germinate to form new filaments Many filamentous cyanobacteria fix atmospheric nitrogen in special cells (heterocysts), which protect the oxygen-sensitive nitrogenase; other cyanobacteria that lack heterocysts can also fix nitrogen Taxonomy of cyanobacteria is unsettled; the 2nd edition of Bergey's Manual divides them into five subsections The prochlorophytes, which used to be categorized separately from other cyanobacteria, are now dispersed into subsections I and III Prochlorophytes differ from other cyanobacteria by having chlorophyll b as well as chlorophyll a and by lacking phycobilisomes
Class Gammaproteobacteria
Largest class of proteobacteria; divided into 13 orders, 20 families, and around 160 genera The Purple Sulfur Bacteria (order Chromatiales) Divided into two families: Chromatiaceae and Ectothiorhodospiraceae Family Ectothiorhodospiraceae contains five genera, including Ectothiorhodospira, which has red, polarly flagellated, spiral-shaped cells that deposit sulfur globules externally and internal photosynthetic membranes that are organized as lamellar stacks The typical purple sulfur bacteria are in the family Chromatiaceae, which contains 22 genera Typical purple sulfur bacteria are strict anaerobes and usually photolithoautotrophs; oxidize hydrogen sulfide to sulfur and deposit it internally as sulfur granules; hydrogen may also serve as an electron donor Genera Thiospirillum, Thiocapsa, and Chromatium are typical purple sulfur bacteria; they are usually found in anaerobic, sulfide-rich zones of lakes
Genera Rickettsia and Coxiella
Members of the genus Rickettsia are in the alphaproteobacteria and members of the genus Coxiella are in the gammaproteobacteria; however they are discussed together because of similar life styles. These bacteria are rod-shaped, coccoid or pleomorphic, with typical gram-negative walls and no flagella; size varies but tends to be small (0.3 - 2.0 um) All are parasitic or mutualistic Rickettsias enter the host by phagocytosis, escape the phagosome, and then reproduce in the cytoplasm by binary fission Coxiella remains in the phagosome after fusion with a lysosome and reproduces within the resulting phagolysosome. For both genera, the host cell eventually bursts releasing new organisms Metabolism of the rickettsias is unusual Lack the glycolytic pathway and do not use glucose as an energy source; instead oxidize glutamate and TCA cycle intermediates Take up nutrients, coenzymes, and ATP from host cell These two genera contain many important pathogens R. prowazekii and R. typhi-typhus fever R. ricketsii-Rocky Mountain Spotted Fever Coxiella burnetii-Q fever They are also important pathogens in dogs, horses, sheep and cattle
Haemophilus influenzae
Meningitis, Upper respiratory infections
Order Myxococcales
Myxobacteria are gram-negative, aerobic soil bacteria with gliding motility, and an interesting life cycle Form fruiting bodies and dormant myxospores All are rods that may be either slender with tapered ends or stout with rounded, blunt ends Micropredators or scavengers that lyse bacteria and yeasts by secretion of an array of digestive enzymes Many also secrete antibiotics to kill prey Use the released peptides and amino acids as primary carbon, nitrogen, and energy source All are chemoheterotrophs with respiratory metabolism Lifestyle resembles that of cellular slime molds When food is plentiful, they migrate along solid surfaces, feeding and leaving a slime trail When their nutrient supply is exhausted, they aggregate and differentiate into fruiting bodies Some cells in the fruiting body develop into myxospores; these are frequently enclosed in walled structures called sporangioles or sporangia Myxospores are dormant and desiccation-resistant; fruiting bodies protect and aid dispersal of myxospores; a colony develops automatically when myxospores are released and this aids digestion by providing higher enzyme concentration than any individual bacterium could Found in neutral soils, decaying plant material, and animal dung; are most abundant in warm areas but will grow in the arctic tundra
Klebsiella
Name the organism: ■ Alcoholic with pneumonia.
Gram-negative aerobic cocci [aka pyogenic cocci along with Gram positives S. aureus & S. pyogenes]
Neisseria gonorrhoeae Neisseria meningitides *Moraxella catarrhalis*
Nitrifying Bacteria
Nitrifying bacteria fall into alpha-, beta-, and gammaproteobacteria, but are considered together here All are aerobic, gram-negative organisms without endospores; able to oxidize either ammonia or nitrite May be rod-shaped, ellipsoidal, spherical, spirillar or lobate with either polar or peritrichous flagella Often have extensive membrane complexes in cytoplasm Are ecologically important Nitrobacter and Nitrococcus oxidize nitrite to nitrate whereas Nitrosomonas, Nitrosospira and Nitrosococcus oxidize ammonia to nitrite If two genera such as Nitrobacter and Nitrosomonas grow together in a habitat, ammonia is converted to nitrate (nitrification) Nitrate is readily used by plants but is also easily leached from the soil or denitrified to nitrogen gas
Class Bacteroides
Obligate anaerobes, nonsporing, chemoheterotrophic, fermentative, rods Found in oral cavity and intestinal tract of humans and other animals and the rumen of ruminants where they often benefit the host by degrading cellulose, pectins, and other complex carbohydrates, thereby providing extra nutrition for the host Some species can be associated with disease Bacteroides species also benefit their host by excluding potential pathogens from colonizing the gut. Some species (B. fragilis, for example) are opportunistic human pathogens, causing infections of the peritoneal cavity, gastrointestinal surgery, and appendicitis via abscess formation, inhibiting phagocytosis, and inactivating beta-lactam antibiotics. Although Bacteroides species are anaerobic, they are aerotolerant and thus can survive in the abdominal cavity. Fusobacterium is a genus of filamentous, anaerobic, Gram-negative bacteria, similar to Bacteroides. Fusobacterium contribute to several human diseases, including periodontal diseases, Lemierre's syndrome, and topical skin ulcers. Although older resources have stated that Fusobacterium necrophorum is a common occurrence in the human oropharynx, the current consensus is that Fusobacterium should always be treated as a pathogen. In contrast to Bacteroides spp., Fusobacteria have a potent LPS
Chlorobia-green sulfur bacteria
Obligately anaerobic photolithoautotrophs that use hydrogen sulfide, elemental sulfur and hydrogen as electron sources; elemental sulfur produced by sulfide oxidation is deposited outside the cell hotosynthetic pigments are located in ellipsoidal vesicles called chlorosomes, which are attached to the plasma membrane but not continuous with it; chlorosome membrane is not a normal lipid bilayer; chlorosomes have accessory bacteriochlorophylls but the reaction center bacteriochlorophyll is located in the plasma membrane Lack flagella and are nonmotile; some species have gas vesicles to adjust their depth in water for adequate light and hydrogen sulfide; species without gas vesicles are found in sulfide-rich mud at the bottom of lakes and ponds. Morphologically diverse (rods, cocci, or vibrios; grow singly, in chains, or in clusters); grass green or chocolate-brown in color
Class Sphingobacteria
Often have sphinolipids in their cell walls Contains several genera including Flexibacter, Cytophaga and Sporocytophaga; differ in morphology, life cycle and physiology Cytophaga-slender rods with pointed ends Sporocytophaga-similar to Cytophaga but form spherical resting cells called microcysts Flexibacter-form long threads; unlike the other two genera, they are unable to degrade complex carbohydrates Physiology (as seen in the genera Cytophaga and Sporocytophaga) Aerobes that actively degrade complex carbohydrates (e.g., cellulose, chitin, keratin) Play a major role in the mineralization of organic matter and can damage exposed wooden structures Contribute significantly to wastewater treatment Most cytophagas are free-living, but some pathogenic species are known (e.g., C. columnaris causes disease in freshwater and marine fish) Are nonmotile when in suspension, but exhibit gliding motility when in contact with a surface; leaves a slime trail; Gliding motility has advantages Enables them to find and digest insoluble material encountered as they move Allows motility in drier habitats Enables them to position themselves for optimal environmental conditions
Pseudomonas aeruginosa
One of several common bacteria that can cause nail infection. Antipseudomonal penicillins, aminoglycosides, carbapenems
Class Betaproteobacteria
Order Neisseriales-contains one family with 14 genera, including the genus Neisseria (described below) Members of the genus Neisseria are nonmotile, aerobic, gram-negative cocci that most often occur in pairs with adjacent sides flattened; may have capsules and fimbriae Chemoorganotrophic, oxidase-positive, and almost always catalase-positive Inhabitants of the mucous membranes of animals; some are human pathogens (e.g., Neisseria gonorrhoeae-causative agent of gonorrhea and Neisseria meningitidis-one of the causative agents of bacterial meningitis)
Class Deltaproteobacteria
Orders Desulfovibrionales, Desulfobacterales, and Desulfuromonadales Gram-negative, sulfate- or sulfur-reducing bacteria; strict anaerobes; use elemental sulfur or sulfur compounds as electron acceptors during anaerobic respiration Important in sulfur cycling within ecosystems Thrive in mud, polluted lake sediments, sewage lagoons and methane digesters, waterlogged soils, and anaerobic marine and estuarine sediments Can have negative impact on industry because of their primary role in the anaerobic corrosion of iron in pipelines, heating systems, and other structures
Cyanobacteria
Photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae).
The three recognized prochlorophyte genera are quite different from one another
Prochloron, Prochlorothrix, Prochlorococcus
Gram-negative aerobic rods (bacilli) Note: these are also lactose negative
Pseudomonas aeruginosa (also oxidase positive and glucose negative) Rhizobium leguminosarum *Xanthomonas * *Agrobacterium*
Type of photosynthetic pigments and oxygen relationships correlates with ecological distribution
Purple and green bacteria are anaerobes and use bacteriochlorophyll pigments Grow better in deeper, anaerobic zones of aquatic habitats Their bacteriochlorophylls absorb shorter wavelengths of light, which penetrate to these deeper zones Cyanobacteria have chlorophyll a, which absorbs longer wavelengths of light; these bacteria are found primarily at the surface of bodies of water
Rickettsia ricketsii
Rocky Mountain Spotted Fever
Bacteroides fragilis
Sepsis/Normal flora in gut Metronidazole
Order Pasteurellales
Small, nonmotile, normally oxidase-positive with complex nutritional requirements Parasitic in vertebrates Four genera: Pasteurella, Haemophilus, Actinobacillus and Lonepinella Best known for the diseases they cause P. multilocida-fowl cholera P. haemolytica-pneumonia in cattle, sheep and goats (e.g. shipping fever in cattle) H. influenzae-major human pathogen that causes a variety of diseases, including meningitis in children
Class Epsilonproteobacteria
Smallest of the proteobacteria groups All are slender, gram-negative rods that can be straight, curved, or helical Contains one order with two families Campylobacter and Helicobacter are the most important genera; both are microaerophiles, motile, helical or vibroid, gram-negative rods Genus Campylobacter-contains both pathogenic and nonpathogenic species C. fetus-reproductive disease and abortions in cattle and sheep; can cause septicemia and enteritis in humans C. jejuni-causes abortion in sheep and enteritis diarrhea in humans Genus Helicobacter Isolated from stomachs and upper intestines of humans, dogs, cats and other mammals H. pylori-cause of gastritis and peptic ulcer disease; produces large quantities of urease and urea hydrolysis appears to be associated with their virulence.
ecologically diverse
Spirochaeta-free-living and often found in anaerobic, sulfide-rich aquatic environments Leptospira-aerobic water and moist soils Many, including Criptispira and Treponema form symbiotic associations with other organisms Some members of Treponema, Borrelia, and Leptospira cause disease (e.g., T. pallidum is the causative agent of syphilis, and B. burgdorferi is the causative agent of Lyme disease)
The five subsections differ markedly in terms of morphology and reproduction
Subsection I-unicellular rods or cocci; most are nonmotile; reproduce by binary fission or budding Subsection II-unicellular, though some may be held together in an aggregate by an outer wall; reproduce by multiple fission to form baeocytes Subsections III, IV, and V-filamentous cyanobacteria
Order Pseudomonadales
The genus Pseudomonas is the most important in this order and contains straight or slightly curved rods; they are motile by polar flagella and lack a sheath or prosthecae Aerobic respiratory chemoheterotrophs, though sometimes carry out anaerobic respiration using nitrate as the final electron acceptor Have functional TCA cycle and use Entner-Dourderoff pathway rather than glycolytic pathway Members of this order have great impact Mineralization of a wide variety of organic compounds; useful in sewage treatment Important experimental subjects Some are major animal and plant pathogens, i.e. P. aeruginosa Some involved in the spoilage of refrigerated food because they can grow at 4oC and degrade lipids and proteins Also in this order is the genus Azotobacter; are large ovoid bacteria that are motile by peritrichous flagella; are aerobic, catalase positive and fix nitrogen nonsymbiotically; are widespread in soil and water
Phylum Chlamydiae
This phylum has only 5 genera; Chlamydia is the most important and best-studied genus Nonmotile, coccoid, gram-negative bacteria Reproduce within cytoplasmic vesicles of host cells by a unique developmental cycle involving elementary bodies (EBs) and reticulate bodies (RBs) Gram-negative-like wall but lacks muramic acid and peptidoglycan; EBs use cross-linking of outer membrane proteins, and possibly, periplasmic proteins to achieve osmotic stability Obligately intracellular parasites; found mostly in mammals and birds but have been recently isolated from spiders, clams, and freshwater invertebrates Has one of the smallest procaryotic genomes
thermophilic species can grow at temperatures up to 75°C
Tolerant of environmental extremes
Spirochetes
Treponema pallidum Borrelia burgdorferi
Chlamydial metabolism
Usually thought of as being completely dependent on host for ATP; however, recent genomic analysis indicates that some genes for ATP synthesis are present in the genome RBs have a number of biosynthetic capabilities (e.g., DNA, RNA, glycogen, lipid, protein, some amino acids and coenzymes) EBs have very little metabolic activity; seem to be dormant forms concerned exclusively with transmission and infection
Vibrios (aka commas)
Vibrio cholera (also lactose negative and oxidase/glucose postitive)
Shigella
What nonmotile gram-negative, non-lactose-fermenting facultative anaerobic rod uses the human colon as its only reservoir and is transmitted by fecal-oral spread?
Serratia
Which bacteria are associated with the following pigment production? • Red pigmentation
Shigella dysenteriae causes
bacterial dysentery or shigellosis
Phylum Cyanobacteria
blue-green algae
Borrelia burgdorferi
causative agent of lyme disease
Erwinia
causes plant rot
C. psittaci
causes psittacosis in humans and infects many other mammals as well; invades the respiratory and genital tracts, the placenta, developing fetuses, the eye, and synovial fluid of the joints
Treponema pallidum
causes syphilis
Order Hydrogenophilales
contains genus Thiobacillus, a prominent member of the colorless sulfur bacteria (use sulfur as electron source, but are not photosynthetic) Thiobacillus-gram-negative rods, lacking extensive internal membranes Thiobacillus-grow aerobically by oaxidizing inorganic sulfur compounds; supply carbon needs with carbon dioxide (chemolithoautotrophs); some are heterotrophs; some grow anaerobically, using nitrate as an electorn acceptor Sulfur-oxidizing bacteria have wide distribution and great practical importance Found in soil and aquatic habitats, especially those acidified by sulfuric acid Their production of sulfuric acid and ferric iron allows them to corrode concrete and pipe structures May also be beneficial by increasing soil fertility and processing low grade ores (leaching)
Order Thiotrichales
contains three families, the largest of which is the Thiotrichiaceae; this family contains some of the colorless sulfur bacteria Genus Beggiatoa Microaerophilic; grow in sulfide-rich habitats Filamentous; lack a sheath Metabolically versatile; can oxidize hydrogen sulfide to sulfur (deposited internally) and can oxidize sulfur to sulfate; can also grow heterotrophically with acetate as a carbon source; some may incorporate CO2 autotrophically Genus Leucothrix Aerobic chemoorganotrophs that form long filaments (trichomes); are marine bacteria that attach to solid substrates by a holdfast Have complex lifestyle in which dispersal is by formation of gonidia Thiotrix is a related genus that forms sheathed filaments and is chemolithotrophic; oxidizes hydrogen sulfide and deposits sulfur granules internally; requires organic compounds for growth (mixotroph); found in sulfide-rich flowing water and activated sludge sewage systems
Prochloron
extracellular symbiont on the surface or within the cloacal cavity of marine colonial ascidan invertebrates
Yersinia pestis (plague)
fleas on prairie dogs (and rats) in the southwest will give you this
purple sulfur bacteria
group of gammaproteobacteria which are obligate anaerobes and oxidize hydrogen sulfide to sulfur
Prochlorococcus
has a modified chlorophyll a and a-carotene rather than b-carotene
Order Bdellovibrionales
has only one family and three genera, including the genus Bdellovibrio (described below) Gram-negative curved rods with polar flagella; prey on other gram-negative bacteria and alternate between a nongrowing predatory phase and an intracellular reproductive phase Have a complex lifestyle Begins with high-speed collision with its prey Enters its prey by boring a hole through the host cell wall; this is accomplished by a combination of mechanical and enzymatic action; flagellum lost during penetration Inhabits the host within the space between cell wall and plasma membrane Inhibits host DNA, RNA, and protein synthesis Disrupts host cell's plasma membrane so cell constituents leak out Grows into long filament and then divides (multiple fission) into many smaller flagellated progeny, which escape when the host cell lyses
Vibrio cholerae (Cholera)
infect the GI tract; remains outside the epithelial cells. Needs rehydration
Acinetobacter calcoaceticus
is a typically short, almost round, rod-shaped Gram-negative bacterium. It can be an opportunistic pathogen in humans, affecting people with compromised immune systems, and is becoming increasingly important as a hospital-derived infection
Chlamydiophila pneumoniae
lung infections in young adults & college students via droplets
C. trachomatis-trachoma
nongonococcal urethritis, and other diseases in humans and mice
Chlamydiophila psittaci
ornithosis, parrot fever
The Three Photosynthetic Bacteria groups?
purple bacteria, green bacteria, and cyanobacteria
Thermotogae
second deepest branch of the bacteria; best studies are members of the genus Thermotoga Hyperthermophiles- with an optimum of 80°C and a maximum of 90°C Grow in active geothermal areas (e.g., marine hydrothermal vents and terrestrial solfataric springs) Deinococcus-Thermus Chemoheterotrophs with a functional glycolytic pathway; can grow anaerobically on carbohydrates and protein digests
Escherichia (O157:H7)
sometimes called VTEC, is a bacterial infection that can cause severe stomach pain, bloody diarrhoea and kidney failure.
Helicobacter pylori
stomach ulcers
Aquificae
thought to represent the deepest (oldest) branch of bacteria; two of its best studies genera are Aquifex and Hydrogenobacter Hyperthermophilic- Archaea adapted to growth at very high temperatures Chemolithoautotrophic- generate energy by oxidizing electron donors such as hydrogen, thiosulfate, and sulfur with oxygen as the electron acceptor
Proteus vulgaris and Proteus mirabilis
use urease and pili as virulence factors to cause urinary tract infections
