BACTE LEC - L2

O antigen

Which specific heat-stable somatic antigen is located on the cell wall of Enterobacteriaceae?

H antigen

What is the heat-labile surface antigen found on structures responsible for bacterial motility?

K antigen

Name the heat-labile capsular polysaccharide antigen found only in certain encapsulated species, such as the K1 of Escherichia coli and Vi of Salmonella Typhi.

• Klebsiella

• Shigella

• Yersinia

Which three genera within the family Enterobacteriaceae are characteristically non-motile at body temperatures?

Green metallic sheen

What macroscopic cultural appearance is typically observed when Escherichia coli is grown on Eosin Methylene Blue (EMB) agar?

Pili

What is the primary uropathogenic Escherichia coli (UPEC) virulence factor responsible for adherence to urinary tract tissues?

ETEC (Enterotoxigenic Escherichia coli)

Which category of diarrheogenic E. coli produces Heat-Labile (LT) and Heat-Stable (ST) enterotoxins and causes traveler's diarrhea?

EPEC (Enteropathogenic Escherichia coli)

Which pathotype of Escherichia coli produces attaching and effacing (A/E) lesions and is a classic cause of infantile watery diarrhea in developing countries?

EIEC (Enteroinvasive Escherichia coli)

Which pathotype of Escherichia coli produces dysentery with direct penetration, invasion, and distruction of the intestinal mucosa?

EHEC (Enterhemorrhagic Escherichia coli)

Which pathotype of Escherichia coli strain serotype 0157:H7 is associated with hemorrhagic diarrhea,colitis, and hemolytic uremic syndrome?

4-methylumbelliferyl-B-D-glucuronide (MUG)

What commercially available fluorescent biochemical test is used to screen bacterial isolates for E. coli O157:H7?

Escherichia hermanni

Name the Escherichia species known for producing yellow-pigmented colonies and being isolated from human cerebrospinal fluid, wounds, and blood.

Escherichia vulneris

Name the Escherichia species that has been isolated from humans with infected wound?

Escherichia albertii

Which bacterial species is the newest member added to the genus Escherichia, recognized for causing pediatric diarrheal disease?

Klebsiella pneumoniae

A frequent cause of lower respiratory tract infections among hospitalized patient and an immunocompromise host

Klebsiella oxytoca

Which Klebsiella species is biochemically identical to Klebsiella pneumoniae except for being positive in the indole test?

Klebsiella pneumoniae subsp. ozaenae

Which Klebsiella species has been isolated from nasal secretions and cerebral abscesses?

Klebsiella pneumoniae subsp. rhinoscleromatis

Which Klebsiella subspecies is isolated from patients with rhinoscleroma, a chronic granulomatous infection of the nasal cavity causing severe facial swelling?

Raoultella spp.

What is the current genus name for organisms previously classified as Klebsiella terrigena?

• Enterobacter cloacae

• Enterobacter aerogenes

what are the two most common enterobacter isolates recovered from clinical specimens such as wounds urine blood and csf?

Pantoea aglomerans

Which bacterial species was involved in a nationwide outbreak of septicemia resulting from contaminated intravenous fluids and is known for producing yellow-pigmented colonies?

Pantoea agglomerans HG XIII

Which species may produce a yellow pigment, is primarily a plant pathogen, depicits a yellow-pigment

Cronobacter sakazakii

Which yellow-pigmented bacterial species, and notorious for causing neonatal meningitis and bacteremia linked to contaminated powdered infant formula?

Salmonella spp.

This genus of primary intestinal pathogens includes species that inhabit the GI tracts of animals, are transmitted to humans through contaminated animal food products like poultry, milk, eggs, and dairy, and are responsible for clinical infections such as acute gastroenteritis (food poisoning), enteric/typhoid fever characterized by symptoms like a prolonged fever and "rose spots", and nontyphoidal bacteremia?

Gastroenteritis

One of the most common forms of "food poisoning," GI infection caused by Salmonellae results from the ingestion of the organisms through contaminated food?

Enteric fever

A febrile disease that results from the ingestion of food contaminated with the organism?

Shigella spp.

This genus of primary intestinal pathogens is unique because humans are the only known reservoir, and it is highly communicable via the fecal-oral route with a very low infective dose required to cause disease. In the laboratory, they appear as clear, non-lactose-fermenting colonies on differential media and are non-motile, while clinically causing bacillary dysentery characterized by stools containing blood, mucus, and pus, as well as potential complications like hemolytic uremic syndrome (HUS)?

Shigella sonnei

This species of Shigella is uniquely distinguished by its ability to slowly ferment lactose (appearing pink on MAC agar after 48 hours), its positive ONPG test, and its rare ability among its genus to decarboxylate ornithine.?

Yersinia pestis

This genus consists of gram-negative coccobacilli with bipolar (safety-pin) staining that prefer lower growth temperatures. While most species are environmental, human pathogens in this group include the causative agent of plague.

Yersinia enterolitica

This is the most commonly isolated species of Yersinia which produces an infection that mimics appendicitis, has been found to be the cause of diarrhea in numerous community outbreaks, and can be acquired from contact with household pets or through the ingestion of contaminated food. 

Yersinia pseudotuberculosis

This pathogen primarily affects rodents (particularly guinea pigs) and birds, and causes a disease characterized by caseous swellings called pseudotubercles?

Serratia spp.

This genus of opportunistic pathogens is associated with healthcare-associated outbreaks, ferments lactose slowly, is ONPG-positive, and is uniquely differentiated from other members of its tribe by its ability to produce extracellular DNase?

Serratia marcescens

This species is considered the most clinically significant within its genus, frequently found in hospital-acquired urinary or respiratory tract infections and nursery/burn unit outbreaks, and it often produces a characteristic pink-to-red pigment called prodigiosin at room temperature?

Serratia odorifera

This species within the genus Serratia contains two biogroups and is distinguished by emitting a dirty, musty odor resembling that of rotten potatoes. 

Hafnia spp.

This genus is composed of the species Hafnia alvei and is characterized by a delayed positive citrate reaction. It features two distinct biotypes: Biotype 1, which grows in the beer wort of breweries and has not been clinically isolated, and H. alvei proper, which has been linked to gastroenteritis and is occasionally isolated from stool cultures?

Proteus spp.

This genus belongs to the tribe Proteeae, is widely disseminated in the environment as normal intestinal microbiota, and is distinguished by its ability to deaminate phenylalanine, hydrolyze urea, produce H2S, and produce "swarming" colonies with a "burnt chocolate" odor on nonselective media like SBA. 

Proteus mirabilis

This is the most common clinical isolate in its genus, capable of producing "swarming" colonies on nonselective media, hydrolyzing urea (which can lead to struvite kidney stones), and is differentiated from another closely related species by being indole-negative and ornithine decarboxylase-positive. 

Proteus vulgaris

This species is a widely recognized human pathogen within its genus that hydrolyzes urea, produces H2S, and is differentiated from Proteus mirabilis by yielding a positive indole test and being ornithine decarboxylase-negative.