Micro Exam 3

Poor Gram staining properties. Ability to cause pneumonia. Ability to diagnose infection with detection of serum antibodies.

Legionella pneumophila and Francisella tularensis share all of the following characteristics

a requirement for cysteine to grow in culture.

Legionella pneumophila and Francisella tularensis share the characteristic of

Oxidase and catalase + **Urease +(CLO Test: rapid urease test)

List the general biochemical characteristics of Helicobacter, identifying the biochemical test most important in its identification.

SMAC

MacConkey with sorbitol (MacConkey agar that contains sorbitol as the carbohydrate in place of lactose)

E. Coli.

MacConkey-sorbitol agar is useful for detecting pathogenic strains of.

Campylobacter.

Making sure that all foods derived from animal sources are thoroughly cooked, all milk is pasteurized, and all drinking water is chlorinated are ways to avoid becoming infected with

Esch. coli

Match the triple sugar iron agar (TSI) agar reaction with the most likely bacterial species Acid slant, acid butt, no H2S

Shigella species

Match the triple sugar iron agar (TSI) agar reaction with the most likely bacterial species Alkaline slant, acid butt, no H2S

Pseudomonas aeruginosa.

Production of exotoxin A, which kills host cells by inhibiting protein synthesis, and production of several proteolytic enzymes and hemolysins that destroy cells and tissue are factors that contribute to pathogenicity of

Vibrio cholerae

Profuse watery diarrhea ("rice water stools"), leading to dramatic fluid loss, severe dehydration, and hypotension that frequently leads to death, is the hallmark of infection with which bacterial species?

Cholera toxin (CT)

Profuse watery diarrhea ("rice water stools"), leading to dramatic fluid loss, severe dehydration, and hypotension that frequently leads to death, is the hallmark of which toxin activity?

Blood Bone marrow Lymph node biopsy

A 57-year-old male farmer sees his physician complaining of fever, night sweats, and lethargy that come and go over the past three months. The patient's history reveals that he raises sheep for wool and meat and goats for milk. The physician suspects undulant fever. What is the optimal specimen(s) for culture of this suspected organism?

Oxidase, TSI slant, growth at 42° C on Mueller-Hinton agar or trypticase soy agar

A convenient and reliable identification scheme for P. aeruginosa involves the following conventional tests:

small, curved or seagull-winged gram-negative bacilli.

Campylobacter spp. can sometimes be detected by direct Gram stain examination of fecal sample, which would reveal many

K antigen

Capsular antigen

CIN

Cefsulodin-irgasan-novobiocin

Enterobacteriaceae

Choose the bacterial family that is best described as catalase-positive, oxidase-negative, gram-negative bacilli that are facultative anaerobes and most of which reduce nitrates to nitrites.

Stomach/ intestinal disease, gastric/duodenal lesions Specimen of choice: duodenal, antral biopsy

Cite the clinical significance and specimen of choice for the cultivation of Helicobacter.

EHEC

Enterohemorrhagic E coli (E coli O157)

Escherichia coli

Enterohemorrhagic, enterotoxigenic and enteroinvasive are terms often linked to which of the following bacterial species?

Pseudomonas

Excluding Enterobacteriaceae, name the second most common gram-negative bacilli encountered in clinical specimens.

· pH Indicator (thymol blue) · Selective agents: sodium citrate, sodium thiosulfate, sodium cholate, and oxbile (inhibit gram positives and coliforms) · Differential agents = sucrose (sucrose fermentation) and sodium thiosulfate/ferric citrate (H2S detection)

Explain the purpose, composition, and principle of TCBS agar. Isolation of Vibrio

oxidase-positive, glucose-fermenting, gram-negative bacilli that grow on MacConkey agar.

Aeromonas, Vibrio, and Plesiomonas are all

Yersinia

Identify the genera of Enterobacteriaceae that is only motile at room temperature.

S. dysenteriae

Identify the serogroups and matching species for the Shigella. Group A

S. flexneri

Identify the serogroups and matching species for the Shigella. Group B

S. boydii

Identify the serogroups and matching species for the Shigella. Group C

S. sonnei

Identify the serogroups and matching species for the Shigella. Group D

gram-negative bacillus.

Indole production, methyl red, Voges-Proskauer, citrate, urease, oxidase, H2S production, and gelatin liquefaction are tests historically performed on a

travel and hide in the reticuloendothelial system.

Infection due to Brucella spp. is often slow to develop, long term, and displaying periodicity. This can be explained by the organism's ability to

· V. vulnificus

primary septicemia, wounds, gastroenteritis

O antigen

somatic antigen located in cell wall of organism

Stool (gastroenteritis- all 4) Wound abscess (all except Campy) Blood (septicemia -all except Plesiomonas)

Name the types of specimen(s) from which Campylobacter, Vibrio, Aeromonas, and Plesiomonas may be isolated

Cefoperazone inhibits Gram-negative, Vancomycin inhibits Gram-positive, Amphotericin B inhibits yeast

State the selective agents contained in Campy-CVA and describe the purpose of each antibiotic in Campy-CVA.

Require microaerophilic environment, fastidious (slow-growing), 42oC, growth can take up to 72 hrs

State the temperature, gaseous environment, and length of incubation required for Campylobacter isolation.

its positive test for catalase.

Actinobacillus actinomycetemcomitans can be distinguished from Haemophilus aphrophilus by

Brevundimonas, Burkholderia, Ralstonia, and Acidovorax were all members of the genus Pseudomonas. Organisms in these genera share many similar characteristics. They are aerobic, straight and slender, gram-negative bacilli whose cells range from 1 to 5 μm in length and 0.5 to 1 μm in width. However there are exceptions to every characteristic listed above. Burkholderia gladioli, Pseudomonas luteola, and Pseudomonas oryzihabitans are oxidase-negative. Pseudomonas alcaligenes, Pseudomonas pseudoalcaligenes, Ralstonia paucula, Ralstonia gilardii, Comamonas spp. (including the former Pseudomonas testosteroni), and Delftia acidovorans (formerly Pseudomonas acidovorans) are not able to utilize glucose oxidatively or fermentively. Acidovorax facilis is MacConkey-negative.

All Brevundimonas, Burkholderia, Ralstonia, Pseudomonas, and Acidovorax share which of the following characteristics?

Pseudomonas aeruginosa

An organism described as oxidase-positive, TSI slant with an alkaline/no change, good growth at 42° C, and producing bright bluish green pigment on Mueller-Hinton agar is most likely

1, 3, and 4

Because of the nature of the profession, a veterinarian is at increased risk of acquiring 1. Brucella spp. 2. Aggregatibacter actinomycetemcomitans 3. Francisella tularensis 4. Streptobacillus moniliformis 5. Eikenella corrodens

Ferment glucose, reduce nitrate to nitrite, and are oxidase negative

Biochemically, the Enterobacteriaceae are gram-negative rods that:

Helicobacter

Curved, microaerophilic, gram-negative rods, with most species having strong urease activity and the majority of which colonize mammalian stomachs or intestines describes which group of bacteria?

All are Gram-negative bacilli, Facultative anaerobes, motile-polar flagella, generally grow on MAC, glucose fermentation +, oxidase +, most are indole +

Describe the general characteristics and biochemical characteristics common to Vibrio, Aeromonas, and Plesiomonas.

Water, seafood (oysters) • Brackish/Marine: Vibrio • Fresh: Aeromonas, Plesiomonas

Describe the habitat of Vibrio, Aeromonas, and Plesiomonas

Catalase and oxidase + Gram-negative bacilli (curved, seagull) Hippurate hydrolysis + Nalidixic acid S, Cephalothin R

Describe the presumptive identification of Campylobacter jejuni

Ingestion of contaminated water/undercooked seafood Aquatic injury (direct inoculation/contamination of wounds)

Describe the route of infection for Vibrio, Aeromonas, and Plesiomonas

EHEC will grow on a SMAC plate and are sorbitol-negative (do not ferment sorbitol = non-pigmented colonies)

Describe the use of SMAC in the isolation and identification of EHEC.

Indole positive

Most strains of Escherichia coli can be presumptively identified based on which characteristic?

· Yersinia enterocolitica · Proteus vulgaris · Serratia marcescens

Name the Enterobacteriaceae that are non-lactose fermenter on MAC, but can ferment sucrose.

· Edwardsiella · Proteus · Providencia · Morganella · Salmonella · Shigella

Name the Enterobacteriaceae that are non-lactose fermenters.

· Klebsiella · Enterobacter · Serratia

Name the Enterobacteriaceae that are positive for Vogues-Proskaeur.

· Proteus · Providencia · Morganella

Name the Enterobacteriaceae that deaminate tryptophan and phenylalanine.

· E. coli · Edwardsiella · Salmonella · Klebsiella · Enterobacter aerogenes · Serratia

Name the Enterobacteriaceae that decarboxylated lysine.

· Edwardsiella · Citrobacter freundii · Salmonella · Proteus

Name the Enterobacteriaceae that produce hydrogen sulfide.

· E. coli · Edwardsiella · Citrobacter koseri · Klebsiella oxytoca · Proteus vulgaris · Providencia · Morganella

Name the Enterobacteriaceae that produce indole.

· Proteus (strong) · Providencia rettgeri and some stuartii · Morganella · Klebsiella · Yersinia enterocolitica (weak)

Name the Enterobacteriaceae that produce urease.

· Citrobacter · Most Salmonella · Klebsiella · Enterobacter · Serratia · Providencia

Name the Enterobacteriaceae that utilize citrate.

· E. coli · Enterobacter · Klebsiella

Name the three Enterobacteriaceae that are rapid (strong) lactose fermenters.

Klebsiella and Shigella

Name the two genera of Enterobacteriaceae that are 100% non-motile

Enterobacteriaceae Family

Not only is this group of gram-negative bacteria considered normal flora of the gastrointestinal tract of humans and animals, but also it contains agents of important diseases such as gastroenteritis and enteric fevers, urinary tract infections, and bacterial pneumonia.

Burkholderia cepacia

Of the species of Burkholderia, which is the one most commonly found in clinical specimens?

gram-negative curved bacilli.

Organisms belonging to the genus Campylobacter are

A/A (sucrose and glucose fermenter; non-lactose fermenter)

State the TSI reaction expected for V. cholerae, explaining the biochemical basis for this reaction.

Halophilic (salt-loving, require 1-2% NaCL to grow) Gram-negative bacilli, straight or slightly curved

State the general characteristics and gram stain morphology of the Vibrio genera

· Aerobic or facultative anaerobes, non-spore former · Oxidase-negative except for Plesiomonas which is oxidase + · Ferment glucose · Reduce nitrates to nitrites · All catalase +, except for Shigella · Grow on MacConkey · Many produce endotoxins · Most are motile (peritrichous flagella)

State the general characteristics of the Family Enterobacteriaceae.

Vibrio

Stool specimens suspected of containing which enteric pathogen should be collected and transported only in Cary-Blair medium because buffered glycerol saline is toxic for this bacterium?

serum

Streptobacillus moniliformis is most easily isolated from blood cultures because it requires _____ for growth.

slow growing and stimulated by carbon dioxide. c. part of the normal oral flora. d. causative agents of bacterial endocarditis.

The HACEK organisms share all of the following characteristics

Burkholderia pseudomallei.

The disease referred to as melioidosis is caused by

oxidase test.

The first biochemical test that is performed on a gram-negative bacillus growing on MacConkey agar to determine the identification scheme is the

Edwardsiella spp.

The gram-negative bacillus that can be described as oxidase-negative, nitrate-positive, and H2S-positive is

Salmonella enteritidis

The gram-negative bacillus that can be described as oxidase-negative, nitrate-positive, indole-negative, citrate-positive, methyl red-positive, urease-negative, H2S-positive is

fastidious and requires special medium. b. infectious for laboratory personnel.

The laboratory should be notified in advance when the physician suspects Francisella tularensis because the organism is

Escherichia coli.

The major etiologic agent of urinary tract infections is

contamination of food, milk, or water with animal feces.

The majority of human infections with Campylobacter species are caused by

Vibrio spp.

The selective medium thiosulfate citrate bile salts sucrose (TCBS) agar is especially formulated for isolating what pathogen from stool cultures?

E. coli

The serotype O157:H7 of which of the following bacterial species is associated with a serious diarrheal illness with high mortality rates among some populations?

Proteus mirabilis

The swarming gram-negative bacillus that can be described as oxidase-negative, nitrate-positive, indole-negative, and H2S- positive is

Proteus vulgaris.

The swarming gram-negative bacillus that can be presumptively identified based on a positive indole test is

toxin's ability to paralyze ciliated epithelial cells.

The virulence of Bordetella pertussis is related to its

ingestion of contaminated seafood or water.

Transmission of Vibrio, Aeromonas,and Plesiomonas shigelloides spp. to humans is by

Plants, soil, and water Medical devices medical solutions Contaminated foods

Which best describes the source of Burkholderia cepacia infections?

Shigella species Salmonella species Yersinia enterocolitica Escherichia coli

Which of the following bacteria are etiologic agents of foodborne gastroenteritis in the United States?

The habitats are limited mostly to water sources.

Which statement best describes the habitats of Vibrio spp., Aeromonas spp., and Plesiomonas shigelloides?

Eikenella corrdens

You and your best friend get into a fist fight. Your knuckles are torn and bleeding afterwards. What organism are you likely to isolate if your wounds become infected?

· V. cholerae

gastroenteritis caused by cholera toxin, profuse diarrhea

· V. parahaemolyticus

gastroenteritis, wounds, septicemia; some produce Kanagawa toxin (hemolysis)

H antigen

flagellar antigen