Haemophilus and Other Fastidious Gram-Negative Bacilli

Question 1

________. are facultative anaerobes and obligates parasites that are primarily adapted to the respiratory tract of humans and other animals

Answer 1

haemophilus spp

Question 2

the only haemophilus spp that causes the sexually transmitted disease chancroid

Answer 2

haemophilus ducreyi

Question 3

they are non motile and facultatively anaerobic, ferment carbohydrates, are generally oxidase and catalase positive, reduce nitrates to nitrites, and are obligate parasites on the mucous membranes of humans and animals

Answer 3

haemophilus

Question 4

haemophilus is derived from the greek word meaning “_________”

Answer 4

blood- lover

Question 5

haemophilus spp with the prefix PARA require only what factor for growth

Answer 5

V factor

Question 6

an important differential characteristics for haemophilus spp

Answer 6

hemolysis on 5% horse or rabbit blood agar

Question 7

both X and V factors are found within red blood cells, however which factor is only directly available

Answer 7

only the X factor

Question 8

why do V factor depended haemophilus spp do not grow on SBA

Answer 8

SBA has intact RBC and it contains NADases that hydrozlye V factor

Question 10

the medium used for recovery of Haemophilus spp.

Answer 10

CHOC agar

it contains lysed RBCs by heat which releases both X and V factor and inactivates NADases

Question 11

a phenomenon that helps in the recognition of haemophilis spp that require V factor is

Answer 11

satellitism

Question 12

explain how satellitism works

Answer 12

we know that haemophilus can’t grow in SBA right? specially if V factor dependent since the rbc is intact and NADases will hydrolyze V factor, so mawawalan ng nutrients si haemophilus

however, it satellitism, haemophilus can grow if lalagyan si SBA ng v-factor-producing organisms such as stap aureus, Strep pneumoniae, or neisseria spp.

maggo-grow si aureus, pneumonia, at neisseria, then sa paligid nito is si haemophilus. Upon the production of V factor by these organism, simultaneously, will be utilized by the haemophilus as their source of nutrients

Question 13

all clinically signifant haemophiluss spp requires V factor for growth and display unusual growth pattern, except which specie?

Answer 13

H.ducreyi

Question 14

commonly referred to as the flu, is a viral disease characterized by acute inflammation of the upper airways

Answer 14

influenzxa

Question 15

symptoms often progress to intense inflammation of the mucous membranes lining the nose, headache, bronchitis, and severe generalized muscle pain

Answer 15

influenza

Question 16

virulence factors of H.influenzae

Answer 16

capsule
IgA proteases
adherence by fimbriae and other structures
outer membrane proteins and lipopolysaccharide

Question 17

not all strains of H.influenza are encapsulated, these strains are commonly reffered to as

Answer 17

nontypable H. influenza

Question 18

the most invasive infections caused by H influenzae is caused by what strain

Answer 18

H.Influenzae serotype b

Question 19

what’s the purpose of secretory IgA in mucosal surfaces of the respiratory tract in fighting bacteria

Answer 19

it binds to bacteria and block their attachment

Question 20

the only genus of Haemophilus that produces IgA proteases

Answer 20

H.Influenzae

Question 21

non encapsulated H,influenza are adherent to epithelial cells, whereas most serotype b strains are not

non encapsulated = makapit, naked kasi diretso kagat
b strains = non adherent

the lack of this adherent capability in type B organisms may explain the tendency for ___

Answer 21

causing systemic infections

Question 22

non encapsulated H,influenza are adherent to epithelial cells, whereas most serotype b strains are not

non encapsulated = makapit, naked kasi diretso kagat
b strains = non adherent

the adherent capability in non encapsulated H influenzae may explain the tendency for ___

Answer 22

causing more localized infections such as acute conjunctivitis

Question 23

describe the invasive disease of H.influenzae

Answer 23

caused by encapsulated strains, bacteremia plays a significant role causing septicemia, meningitis, arthritis, epiglottis, tracheitis, and pneumonia

Question 24

describe the second and more common pattern of disease of H.influenzae

Answer 24

localized due to non encapsulated

Question 25

H.influenza along with ____ is a common cause of middle ear infections in children

Answer 25

S. pneumoniae

Question 26

H.aegyptius is also calle as

Answer 26

kock-weeks bacillus

Question 27

H.aegyptus or koch-weeks bacillus is genetically related to

Answer 27

H.influenzae

Question 28

associated with an acute, contagious conjunctivitis, commonly reffered to as "pink eye "

Answer 28

H.aegyptius

Question 29

a strictly human pathogen, is the causative agent of chancroid

Answer 29

H.ducreyi

Question 30

a highly communicable sexually transmitted genital ulcer disease

Answer 30

H.ducreyi

Question 31

chancroid is commonly reffered to as ____

Answer 31

soft chancre

Question 32

H.ducreyi - soft chancre __________ - hard chancre

Answer 32

syphilis

Question 33

commonly used agar for H influenzae

Answer 33

CHOC agar

Question 34

colonies of H.influenzae on CHOC agar appear _______ with an odor of _________

Answer 34

appears translucent, tannish, moist, smooth, convex, with an odor of mousy or bleach-like

Question 35

what type of disease is pasteurellosis

Answer 35

zoonosis

Question 36

safety pin appearance when the poles of the cells are more intensely stained - this type of staining is observed in

Answer 36

pasteurella spp- bipolar staining