Gram - bacteria T03 Flashcards
Bacilli and cocci included
What does it mean by facultative anaerobic?
A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent.
Which of the following are features of Enterobacteriaceae?
A. They are facultative anaerobes
B. They are glucose fermenters
C. They are oxidase-positive
D. In serology, they contain specific antibodies to O, H and Vi antigens
All except C
They are oxidase -ve
Which of the below are lactose fermenters which will show red color in MacConkey Agar ?
A. E.coli B. Klebsiella C. Enterobacter D. Serratia E. Cirtrobacter F. Proteus G. Shigella H. Salmonella
What color will others show?
Lactose fermenters:
A,B,C (E.coli, Klebseilla, Enterobacter)
Whic of the following are non-motile and which of the following is with swarming motility?
A. E.coli B. Klebsiella C. Enterobacter D. Serratia E. Cirtrobacter F. Proteus G. Shigella H. Salmonella
Non-motile:
B, G (Shigella and Klebsiella)
Swarming motility: F
Which of the following will give indole + test?
A. E.coli B. Klebsiella C. Enterobacter D. Serratia E. Cirtrobacter F. Proteus G. Shigella H. Salmonella
A: E.coli
Which of the following gives red-orange pigment in biochemistry test?
A. E.coli B. Klebsiella C. Enterobacter D. Serratia E. Cirtrobacter F. Proteus G. Shigella H. Salmonella
D: Serratia
Which of the following have mucoid colonies, VP+, Quellung +, and urease +?
A. E.coli B. Klebsiella C. Enterobacter D. Serratia E. Cirtrobacter F. Proteus G. Shigella H. Salmonella
B. Klebsiella
What Enterbacteriacceae will give urease + test and H2S+ test. (swarming motility too!)
Proteus
Shigella shows H2S+/-?, which is _________(color) in DCA agar.
H2S-, green
Salmonella shows H2S+/-?, which is _________(color) in DCA agar.
H2S+, black
Enteropathogenic Escherichia coli (EPEC) is associated in what patients?
paediatrics
Enterotoxigenic Escherichia coli (E. coli) is associated with?
Traveller’s diarrhea
Enteroinvasive E. coli (EIEC) is associated with?
Inflammation
Enterohemorrhagic Escherichia coli (EHEC) is associated with?
Hamburger meat, bloody stool
Uropathogenic E. coli (UPEC) is asscioated with?
UTIs
What are the clinical manifestations of E.Coli infections? (4)
- UTI: 90% cause
- Intra-abdominal infection
- Neonatal meningitis: 2nd cause after GBS
- hemolytic uremic syndrome by EHEC
Which of the following about E.coli is incorrect?
A. All of them causes diarrhea
B. Indicator organism faecal contamination
C. All of them are glucose fermenters
D. They turn MacConkey Agar red because they are all lactose fermenters
A
C: a family feature of Enterobacteriaceae!
This G- bacilli forms capsule and become mucoid colonies which are anti-phagocytic.
Klebsiella
List the clinical manifestations of infections by Klebsiella.
- Nosocomial pneumonia
2. UTI: catheter-related abscess (e.g. cholecystitis, liver abscess)
__________ is also a type of Enterobateriaceae whihc is only different from E.coli by biochemistry.
Enterobacter
Proteus is produces urease which raises urine pH by splitting urea, causing struvite kidnet stones, it is related with what clinical manifestations?
- UTI
2. Septicemia
Shigella directly invades mucosal cells but will not invade further. It releases ______________, and causes?
Shiga toxin (Enterotoxin);
- Baciliary dysentery: meaning diarrhea which turns from watery to bloody
- Hemolytic uremic syndrome
Which of the following about Shigella is incorrect?
A. Human is their only reserviour
B. It is a notifiable disease
C. It is transmitted via fecal-oral route
D. It is acid stable, with a low infective dose
E. It causes osteomyelitis in sickle cell disease patients
E
should be Salmonella
also, there are different species for Shigella:
- S.dysenteriae
- S. flexneri
- S. boydii
- S. sonnei
Other than osteomyelitis in sickle cell disease patients in general that Salmonella can cause, suggest types of Salmonella that causes Gastroenteritis and Typhoid fever respectively.
GE group: S.enteritidis (chicken), S. choleraesuis
Typhoid fever group: S. typhi (humans only), S. paratyphi
Which of the following about Salmonella is incorrect?
A. It turns DCA agar black
B. It is motile
C. There is increased risk of infection in people with reduced stomach acidity like patients with pernicious anemia
D. It is transmitted via fecal-oral route
None of the able
A: H2S+
C: acid labile; therefore without acid > increased infection
What are the ESKAPE organisms with antimicrobial resistance?
Enterococci; S.aureus, Klebsiella, Acinetobacter, Pseudomonas, Enterobacter
What are the common features between Pseudomonas aeruginosa and Acinetobacter baumanii?
They are glucose-non fermenter
multi-drug resistant
Which of the following about Pseudomonas aeruginosa is incorrect? Explain.
A. It is oxidase + B. It produces a green pigment C. It is a strict aerobe D. It is catalase + E. It is associated with GE
E
Should be associated with nosocomial pneumonia/UTI
Acinetobacter baumanii is a coccibacilli and is transmitted via _________ in is related with _______ infections
Skin contact;
nosocomial
Which of the below G- bacilli appear as curved rods?
A. Pseudomonas aeruginosa B. Acinetobacter baumanii C. Vibrio D. Campylobacter E. Helicobacter F. Hemophilus influenzae G. Legionella pneumophillia
C,D,E
Vibrio
Campylobacter
Helicobacter
This bacteria is in comma shape, oxidase +, and is a glucose fermenter. It shows yellow in TCBS medium. What bacteria is it and what does it mean by yellow in TCBS medium?
Vibrio cholerae - sucrose fermenter
This bacteria is in comma shape, oxidase +, and is a glucose fermenter. It shows green in TCBS medium. What bacteria is it and what does it mean by green in TCBS medium?
Vibrio parahaemolyticus - non-surcrose fermenter
What are the clinical manifestations for Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus respectivitly?
Vibrio cholerae: Cholera
Vibrio parahaemolyticus: GE
Vibrio vulnificus: SSTI (severe soft tissue infection), necrotising fasciitis
What are the 2 bacteria you’ve learnt that causes necrotising fascitis?
- Group A Strep/ Streptococcus pyogenes
2. Vibrio vulnificus
This type of bacteria shows a seagull shape in medium and is best grown in 42 degrees and a microaerophillic environment. State other features that it may show, also state the name of it.
Campylobacter:
- Silver tear drop colonies in Skirrow agar (that suppress other bacteria as its a stool sample)
The reserviour for Campylobacter is ?
Poultry
Name the 3 clinical manifestations of Campylobacter infections
- GE (bloody diarrhea which is self-limiting)
- Reactive arthritis
- Post-infection: GBS
A patient with peptic ulcer and CA stomach is infected with a urease + G- bacilli. Name the bacilli.
Helicobacter (pylori)
Name the 3 fastidious G- bacilli.
- Haemophilus influenzae
- Legionella pneumophila
- Bordetella pertussis
Which G- bacilli grow on chocolate agar and shows satellism near S. aureus? Why? It is also considered to be a pleomorphic coccobacilli.
Haemophilus influenzae
- On blood agar is due to presence of haemin/ X factor
- near S.aureus is due to presence of NAD/ Y factor
What are the clinical manifestations of patients infected with Haemophilus influenzae?
(3 mainly)
- Bronchitis, pneumonia
- Bacteraemia
- Meningitis
Which bacteria will cause atypical pneumonia and can grow in BCYE? (buffered charcoal yeast extract) They are also found in stagnant water.
Legionella pneumophila
Which of the following about Bordetella pertuissis are correct?
A. They are strict aerobes
B. They grow in Bordet-Gengou agar
C. They grow in charcoal-containing medium
D. It is preventable with the DTaP vaccine
All of the above
What are the clinical manefistations of Pertussis?
- Whooping cough
2. Post-pertussis vomiting
Which G-bacilli is related to “Black Death/Plague”? What is the other G- bacilli which possess the feature of Zoonotic transmission as well?
Yersinia pestis;
Brucella
What disease will Brucella cause?
- Persistent fever
2. Bactermiea
List the 2 Genus which are G- cocci.
Neisseria and Moraxella (catarrhalis)
The specimen appears to be kidney-bean shaped diplococci. They are oxidase + and can grow in NYC and chocolate agar.
List 2 bacteria that shows the above features.
Neisseria meningitidis
Neisseria gonorrhoeae
State a method to differentiate between Neisseria meningitidis and N. gonorrhea.
N. gonorrhea does not ferment maltose but N. meningitidis ferments maltose.
Both ferments glucose!
Clinical manifestations of N.gonorrhoeae. (3)
- Gonorrhoae
- Neonatal conjunctivitis
- Asymmetric arthritis
What are the 2 clinical manifestations of N. meningitidis and how can it be prevented?
- Meningitis
- Bacteraemia
- Prevention: ACWY meningococcal vaccine
Moraxella catarrhalis is a close relative of Neisseria. However, it does not ferment both glucose and maltose and they grow on plain agar. List 3 clinical manifestations of it.
- Bronchitis
- Acute otitis media
- Pneumonia
Do N.gonorrhoeae and N. meningitidis grow on plain agar?
No. They are fastidious, enriched media are required for growth.
A 2 y/o baby showed signs of meningitis. CSF was taken and Gram’s smear is red with rod shaped bacteria. What is the propable identity of the organism?
E.coli (due to vaginal colonization)
What are the possible causes to neonatal meningitis? (G+ and G-)
- Gram+ cocci in chains - GBS
- Gram + bacilli: Listeria monocytongenes (blood stream infections, C section/vaginal)
- Gram- bacilli in rods: Enterobacteriaceae.coli
A skin swab grew on organism from a patient admitted to burns unit for one month. It appears to be green pigments on a clear agar. Name the pathogen.
Pseudomonas aeruginosa
nosocomial infection without skin protection
A patient was suffereing from severe abdominal pain and diarrhea after taken a meal at Japanese restaurant. Green colonies were growing on the TCBS medium. What is the probable organism?
Green =?
Vibrio parahaemolyticus
non-sucorse fermenting
A patient had a hotpot night. He presented with nausea, vomiting and bloody diarrhea. Stool culture revelaed an organism after incubation under microaerophilic condition for 48 hours. What is the most probable diagnosis? (pink and wavy look)
Campylobacter gastroenteritis
diagnosis! not the organism!
A twenty-year told male showed sign of neck rigidity and red spots on the body. Both blood and CSF were taken. No organism was seen from the Gram’s smear. An organism was grown on blood agar. What is the probable organism?
Neisseria meningitidis.
G- cocci in pairs
A 40 year old man who had a history of unprotected sexual exposure a week ago, presented with symptoms of a profuse mucoid urehtral discharge. It rapidly became purulent. What is the likely diagnosis?
How can you differentiate this organism from the other G- diplococci.
Neisseria gonorrhoeae.
They are BOTH extracellular and intracellular!
Other G- diplococci include N. meningitidis/ Moraxella catahhralis
from N.meningitidis: gonorrhoeae does not ferment maltose.
from Moraxella: gonorrhoeae ferments glucose
Slide agglutination test (SAT) can be used to identify?
What are the + and - test results?
Shigella and Salmonella
+: agglutination meaning clumps of bacteria
-: homogenous white suspension
What G- bacilli are H2S+? (turns filter paper black)
- Proteus
2. Salmonella typhi
Only shows a +ve result in indole test. (turns filter paper red/pink?)
E.coli
What G- bacilli are urease +?
Klebsiella and Proteus
