11 - Cronobacter Flashcards
What is the older name of Cronobacter (before 2007)
Enterobacter Sakazakii
Cronobacter typical outbreak:
- infant fed on PIF
- neck rigidity
- rehydration
- seizure-lie activity
How is Cronobacter often reported after autopsy in infants?
It is often reported as SIDS (sudden infant death syndrome) as the cause of death
Cronobacter is recognized as a _________________ coliform
yellow-pigmented
There are now ___ recognizes species of Cronobacter
11
Which Cronobacter species have been involved in neonatal infection (3):
- C.sakazakii
- C.turicensis
- C.malonaticus
Give me the Cronobacter characteristics (gram, etc)
- Gram negative
- non-spore forming
- straight
- rod-shape bacteria
Cronobacter has a ________ is ________________ (nonhalophilic/halophilic), and _____________ anaerobic and grows from ______ to _____
flagellum
nonhalophilic
facultatively
6-45C
T or F: Originally described as a yellow-pigmented coliform, the yellow pigment as well as well as the cell morphology may be lost or change upon repeated sub-culturing.
T
T or F: Cronobacter is an emerging pathogen
T
In 1990 Cronobacter was linked to ___________
powdered infant formula (PIF)
T or F: There is a year to year increase of Cronobacter
T
There have been approximately __ recorded cases of Cronobacter in adults
20
Epidemiology of Cronobacter (describe it)
low number of cases but high number of deaths
What group is at the most risk for Cronobacter?
PIF fed infants less than 1 year of age
Immunocompromised and neonates younger than 28 days old are at the greatest risk
T or F: Low birth-weight neonates could possibly be at higher risk
T
T or F: Cases are higher in the developed world than in the developing
T
Why premature infants born at less than 37 weeks are at particular risK?
- they should be fed breast milk
- they secrete less gastric acid than older infants, and this may be important in the long-term survival of Cronobacter
- HIV positive mothers cannot breast feed
Infants infected with Cronobacter often suffer from:
- Necrotizing enterocolitis (NEC)
- Septicemia
- Meningitis
Neurological sequelae are common and include:
- Brain abscess
- Necrosis of brain tissue
- Liquefaction of white cerebral matter
Name food products that are not linked to illness but have been found to harbor Cronobacter:
- Milk powder
- Cheese
- Herbs
- Spices
- Rice
___________________ is the most associated vehicle for transmission of the pathogen, being an intrinsic or extrinsic contaminant during manufacturing under poor good manufacturing practices (GMP) or reconstitution of PIF
Reconstituted PIF
T or F: Voluntary recalls of PIF contaminated with Cronobacter in the United States, Europe and Asia-Pacific region suggested the need of a collective effort among PIF manufacturers, health-care facilities and governing bodies to develop hygienic practices and maintain higher microbiological standards
T
Why is the PIF form used over liquid form?
Because it is better in terms of cost and storage
The _______ form is sterile and the ________ form may contain low levels of microorganisms
liquid
PIF
T or F: Current processing technology is able to completely eliminate the potential for microbial contamination without affecting organoleptic and nutritional requirements
F
Based on current knowledge sterilization of PIF seems to only be possible using __________
irradiation
*however, the doses that are required to kill all Cronobacter are not feasible do to organoleptic deterioration
What are the other approaches that are currently being researched to kill Cronobacter:
- magnetic fields
- ultrahigh pressure
In terms of virulence factors. how much is known about Cronobacter pathogenesis?
Little is known about Cronobacter pathogenesis
Name some virulence factors of Cronobacter sakazakii
- apical attachment
- apical invasion
- disruption of tight and adherens junction
- basolateral invasion
What are the outer membrane proteins (OMPs) genes involved in invasion of epithelial cells, involved in BBB
ompX, ompA
What is a gene associated with outer membrane protease ?
cpa, provides protection from the immune system
_________________ are of particular interest, owing to their cell-surface exposure and contribution in export of virulence factors, and in anchoring the structures that mediate adhesion and motility
Outer membrane proteins
______ helps cells adhere to GI epithelial cells
OmpA
Only __________ Cronobacter breech the blood brain barrier
OmpA positive
______ helps invasion on the apical side of GI epithelial cells, but also helps Cronobacter survive the basolateral side as well
OmpX
A study on C. sakazakii reported the presence of a plasmid ______ encoding an outer membrane proteases (cpa)
pESA3
The cpa protease has an ability to :
- render serum resistance by cleaving complement components
- activates a plasminogen
- inactivate a plasmin inhibitor
The pESA3 plasmid also encodes a ________________ and some adhesion factors
type 6 secretion system
Sialic acid is found in human milk and in infant formulae in the form of ____________________.
sialyloligosaccharides.
The sialyoligosaccharides remain ________ in neonates and infants, therefore the intestinal microvilli of neonates have increased sialic acid levels
undigested
It is plausible that there is a linkage between sialic acid __________ of C. sakazakii as it is the only Cronobacter species possessing the _______ gene cluster encoding for sialic acid utilization
pathogenicity
nanAKT
the nanAKT gene cluster encodes for ____________
sialic acid utilization
What are some things you can do to prevent Cronobacter sakazakii?
- refrigerate prepared infant formula to 4C within 1 hour of preparation
- prepare only small volumes of PIF to reduce the hang time at room temperature before consumption (hang time should never exceed 4 hours)
- use only chilled, sterile water for IF preparation
- discard any IF remaining in the bottle after feeding
- Use PIF within 4 weeks of opening the can
- Sterilize bottles prior to reconstitution
T or F: there are 11 species of Cronobacter
T
Mortality rates associated with Cronobacter infection are _______ and even survivors will likely have permanent developmental damage
very high
Cronibacter infections are probably ________ due to being diagnosed as SIDS
underreported
