Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Unit 4 Chapter 19
Enterobacteriaceae
| Question | Answer |
|---|---|
| key characteristics of the Family Enterobacteriaceae | gram-negative, non-spore-forming, faculatively anaerobic bacilli; can appear as coccobacilli or as straight rods; can produce large mucoid colonies, large moist, gray colonies |
| Enterobacteriaceae *virulence factors* | ability to adhere, colonize, produce toxins, and invade tissue; some species harbor plasmids that can provide antimicrobial resistant genes; produce plasmid-mediated extended spectrum β-lactamase |
| Enterobacteriaceae *antigenic factors* | O antigen, H antigen, K antigen |
| E. coli *colony morphology* | motile, generally possess adhesive fimbriae and sex pili and O, H, and K antigens; usually appears as a lactose-positive colony with a surrounding area of precipitated bile salts on MAC agar, green metallic sheen on EMB, facultatively anaerobic |
| E. coli *gram stain results* | gram-negative rods |
| E. coli *testing results* | fermentation of glucose, lactose, trehalose, and xylose; production of indole from tryptophan; glucose fermentation by the mixed acid pathway: methyl red positive and Voges-Proskauer-negative; does not produce H2S, DNase, urease, orphenylalanine deaminase |
| E. coli *virulence factors* | enteropathogenic, enterotoxigenic, enteroaggreative |
| E. coli *epidemiology* | intestinal tract of humans and many other animals |
| E. coli *infections* | UTI, infantile diarrhea, hemorrhagic diarrhea, colitis, HUS, dysentry, traveler's diarrhea, persistent pediatric diarrhea, pediatric diarrhea, septicemia and menegitis |
| uropathogenic E. coli | widely recognized as most common cause of UTIs in humans |
| enteradherent pathogens EPEC, EHEC, EIEC, ETEC | EPEC: pathogenicity islands (infantile diarrhea); EHEC: shinga toxin/ verotoxin (hemorrhagic diarrhea, colitis, HUS); EIEC: invasion (dysentry); ETEC: LT, ST (traveler's diarrhea) |
| enteradherent pathogens EAEC and DAEC | EAEC: AAF fimbriae Afa/Dr adhesions, AIDA-1, pathogenicity islands (persistent pediatric diarrhea); DAEC: (pediatric diarrhea, UTIs) |
| Klebsiella *colony morphology* | variable motility, grow on Simmons citrate and in potassium cyanide broth, moist mucoid colonies |
| Klebsiella *gram stain results* | gram-negative bacilli |
| Klebsiella *testing results* | non produce H2S, few hydrolyze urea slowly, mthyl red-negative, Voges-Proskauer-positive, no indole is produced from tryptophan |
| Klebsiella *virulence factors* | large polysaccharide capsule |
| Klebsiella *epidemiology* | usually found in the GI tract of humans and animals |
| Klebsiella *infections* | wound infections, UTIs, liver abscesses, and bacteremia |
| Enterobacter, Cronobacter, Pantoea *colony morphology* | resembles Klebsiella on MAC agar, grow on Simmons citrate and in potassium cyanide broth, yellow pigment |
| Enterobacter, Cronobacter, Pantoea *gram stain results* | |
| Enterobacter, Cronobacter, Pantoea *testing results* | methyl red-negative, Voges-Proskauer-positive, usually produceornithine decarboxylase; Lysine decarboxylase |
| Enterobacter, Cronobacter, Pantoea *virulence factors* | produce ornithine decarboxylase |
| Enterobacter, Cronobacter, Pantoea *epidemiology* | isolated from human sources such as blood, wounds, and sputum |
| Enterobacter, Cronobacter, Pantoea *infections* | meningitis, bacterimia |
| Serratia *colony morphology* | red pigment when growing at room temp |
| Serratia *gram stain results* | gram-negative rod |
| Serratia *testing results* | positive ONPG, positive for sucrose (biogroup 1), raffinose, and ornithine, (biogroup 2) indole-positive |
| Serratia *virulence factors* | DNase, highly resistant to antimicrobials |
| Serratia *epidemiology* | isolated from human sources |
| Serratia *infections* | nosocomial infections of the urinary tract, respiratory tract, bacteremia |
| Hafnia *colony morphology* | Motility occurs at 30 degrees C. by peritrichous flagella; Colonies are non-lactose-fermenters and may resemble Salmonellae. Most strains are translucent or colorless; rare strains may produce red or pink colonies on media containing sucrose. |
| Hafnia *gram stain results* | gram-negative rod |
| Hafnia *testing results* | Oxidase-negative; Catalase-positive; Lysine- and ornithine-decarboxylase-positive; H 2 S (Triple Sugar Iron - TSI)-negative; Urease-negative; Indole-negative; DNase-negative; ONPG-positive; Reduces Nitrate to Nitrite |
| Hafnia *virulence factors* | no capsules or spores |
| Hafnia *epidemiology* | occurs in man and animals and birds, and in natural environments such as soil, sewage and water; found in clinical specimens, especially from feces, occasionally blood, sputum, urine, and wounds, abscesses, the throat, abdominal cavity and autopsies. |
| Hafnia *infections* | H. alvei seem to be opportunistic pathogens which produce infections in patients with underlying illnesses; a possible causative agent of intestinal disorders; no conclusive evidence has been obtained regarding its enteropathogenicity |
| Proteus *colony morphology* | produces swarming colonies on SBA |
| Proteus *gram stain results* | gram-negative rod |
| Proteus *testing results | some are negative for H2S, differentiated by indole and ornithine decarboxylase tests, |
| Proteus *virulence factors* | have numerous factors including fimbriae, flagella, outer membrane proteins, lipopolysaccharide, capsule antigen, urease, immunoglobulin A proteases, hemolysins, amino acid deaminases, and, finally, the most characteristic attribute of Proteus |
| Proteus *epidemiology* | isolated from urine, wounds, and ear and bacteremic infections |
| Proteus *infections* | responsible for 3% of all hospital acquired infections particularly UTIs, causes lower and upper urinary tract infection, |
| Morganella *colony morphology* | facultative anaerobes, motile |
| Morganella *gram stain results* | Gram-negative bacillus |
| Morganella *testing results* | oxidase negative and catalase positive. acid and gas from the metabolism of D-glucose, indole positive, VP negative, MR positive, can be grown in KCN, urease positive, |
| Morganella *virulence factors* | enzyme, that is resistant to some urease. While, they are resistant to amoxicillin-clavulanic acid, cephalothin, gentamicin, penicillin, piperacillin, tetracycline, and trimethoprim-sulfomethaxzole. |
| Morganella *epidemiology* | intestinal tract of humans and other mammals and reptiles |
| Morganella *infections* | endophthalmitis, central nervous system infections, Ludwig’s angina, bacteremia, and urinary tract infection |
| Providecia *colony morphology* | All are motile, with peritrichous flagella, |
| Providecia *gram stain results* | gram-negative rod |
| Providecia *testing results* | oxidatively deaminate phenylalanine hydrolyze urea |
| Providecia *virulence factors* | invasive isolates |
| Providecia *epidemiology* | The modes of transmission may include nosocomial sources, such as hospital food and equipment, intravenous solutions and human contact through contaminated sk in surfaces. Long-term indwelling catheters are a prime site of colonization and |
| Providecia *infections* | UTI |
| Edwardsiella *colony morphology* | MacConkey agar they form pale coloured colonies which can become pink on further incubation due to fermentation of lactose which can be late. |
| Edwardsiella *gram stain results* | Gram-negative, facultatively anaerobic, rod-shaped bacteria |
| Edwardsiella *testing results* | slow or weak fermentation of sugars by this organism. Only glucose and maltose are fermented. It is indole positive, utilise citrate, urease negative. |
| Edwardsiella *virulence factors* | non-capsulated, motile, produce hydrogen sulphide in KI medium |
| Edwardsiella *epidemiology* | Normal habitat is intestine of cold blooded animals and fresh water. It is mainly pathogenic to water animals |
| Edwardsiella *infections* | causes occasional infection in humans. Its pathogenic role is uncertain but it has been isolated from wound, urine, blood and CSF |
| Erwinia *colony morphology* | appear as white, smooth colonies; may be domed, shining, mucoid-type colonies with radial striations or appear smooth with entire edges. Craters may form around the colonies on some media. Pigments ranging from cream, pale yellow-light pink. |
| Erwinia *gram stain results* | gram-negative rods, pairs or chains |
| Erwinia *testing results* | Catalase-positive. PYR-positive. (Pyrrolidonyl-beta-naphthylamide). ONPG-positive (beta-galactosidase). Acid produced from carbohydrates. Oxidase-negative. Nitrates are not reduced. Moeller's-decarboxylase-negative. |
| Erwinia *virulence factors* | Type III secretion system (T3SS), the exopolysaccharide (EPS) amylovoran, biofilm formation, and motility |
| Erwinia *epidemiology* | major global threat to commercial apple and pear production |
| Erwinia *infections* | plant pathogens, are not significant in human infections |
| Pectobacterium *colony morphology* | n Logan’s medium and did not produce blue pigmented indigoidine on GYCA medium nor “fried egg” colonies on PDA. |
| Pectobacterium *gram stain results* | non-fluorescent, gram-negative, facultative anaerobes |
| Pectobacterium *testing results* | oxidase-negative and catalase-positive; did not produce acid from α -methyl glucoside, sorbitol and maltose, nor reducing substances from sucrose, but utilized lactose and trehalose, and did not produce indole or lecithinase. |
| Pectobacterium *virulence factors* | type II secretion system (T2SS) , adhesions , metalloproteases , and a type III secretion system (T3SS) |
| Pectobacterium *epidemiology* | ubiquitous in soil, wa ter, and atmospheric samples worldwide and can infect species from 24 orders of plants |
| Pectobacterium *infection* | soft rot disease |
| Citrobacter *colony morphology* | grow well on ordinary media producing smooth, convex, non pigmented 2-3 mm colonies |
| Citrobacter *gram stain results* | gram negative bacilli, motile with peritrichous flagella, non-sporing, non-acid fast |
| Citrobacter *testing results | indole= + except C.freundii, MR= +, VP = neg, Citrate positive, urease weakly positive, H2S is produced by C.freundii. Mannitol fermentation- positive. Lactose fermentation-positive variable, always produce β-galactosidase (ONPG positive). |
| Citrobacter *virulence factors* | endotoxins, O (somatic) and H (flagellar) antigen, capsular antigen, adhesion proteins produced by bacteria. |
| Citrobacter *epidemiology* | normal commensals of human gastrointestinal tract |
| Citrobacter *infections* | They can cause UTI, infection of gall bladder, middle ear. C.koseri may occasionally cause neonatal meningitis. |
| primary intestinal pathogens from the Enterobacteriaceae | Salmonella, Shigella, Yersinia |
| Salmonella *colony morphology* | faculatively anaerobic, clear colorless, nonlactose fermenting with black centers |
| Salmonella *gram stain results* | gram-negative bacilli |
| Salmonella *testing results* | do not ferment lactose; indole negative; Voges-Proskauer negative; phenylalanine deaminase negative; urease negative; produce H2S (except Salmonella Paratyphi A); do not grow with potassium cyanide |
| Salmonella *virulence factors* | fimbriae in adherance, ability to transverse intestional mucosa |
| Salmonella *epidemiology* | found in cold-blooded animals as well as in rodents and birds |
| Salmonella *infections* | acute gastroenteritis (food poisoning); Typhoid fever; Nontyphoidal bacterimia; carrier state following infection |
| Shigella *colony morphology* | clear, non-lactose-fermenting |
| Shigella *gram stain results* | Gram-negative, nonmotile, nonspore forming, rod-shaped |
| Shigella *testing results* | nonmotile; only S. flexneri produce gas from glucose; do not hydrolyze urea; do not produce H2S; do not decarboxylate lysine; |
| Shigella *virulence factors* | acid tolerance; effector proteins; the Mxi-Spa T3SS, toxins; motility; adherence; |
| Shigella *epidemiology* | humans are reservoir though can be transmitted by flies, fingers, and food or contaminated water |
| Shigella *infections* | dysentry; fever watery diarrhea; gastroenteritis; |
| Yersinia pestis *colony morphology* | gray-white translucent on BAP and chocolate; may appear opaque and yellow in 48hrs; "fried egg" or "hammered copper" on Ba in older cultures; Clear or white on MAC at 48hrs |
| Yersinia pestis *gram stain results* | gram-negative, short plump bacillis |
| Yersinia pestis *testing results* | non-motile; catalase positive; oxidase negative; urease negative; indole negative; flocculent or "stalacite" growth in broth |
| Yersinia pestis * virulence factors* | encoded with plasmids; codes for phospholipase; codes for a protease, activates plasminogen in human hosts; encode several proteins; adhesion; multiply in macrophages; produce pro-inflammatory cytokines |
| Yersinia pestis *epidemiology* | inhalation, flea bites |
| Yersinia pestis *infections* | plague, bubonic, gladular, septicemic, and pneumonic |
| Yersinia enterocolitica *colony morphology* | motile at 25°C/nonmotile 36°C non-spore-forming, faculatively anaerobic |
| Yersinia enterocolitica *gram stain results* | gram-negative coccobacillus |
| Yersinia enterocolitica *testing results* | Glucose fermenation without gas production, urea usually positive (about 75%), H2S negative. Lactose negative (but ONPG positive), sucrose and mannnitol positive. |
| Yersinia enterocolitica *virulence factors* | some strains can produce small amount of ga |
| Yersinia enterocolitica *epidemiology* | zoonotic disease occurring in humans as well as a wide array of animals such as cattle, deer, pigs, and birds. |
| Yersinia enterocolitica *infections* | usually lead to mild self-limiting enterocolitis or terminal ileitis in humans |
| screening stool cultures for pathogens | |
Created by:
luceroapril
Popular Laboratory Science sets