Coliforms Flashcards
Are coliforms lactose fermentors or lactose nonfermentors?
Lactose fermentors
Coliforms are apart of CEEK.
Citrobacter
Enterobacter
Klebsiella
Name the sites of colonization and extraintestinal disease production by coliforms and Proteus.
Name the three important species of Klebsiellla. Which of these members are apart of ESKAPE?
Three species are super important
1. K. aerogenes
2. K. pneumoniae
3. K. oxytoca
K. aerogenes, K. pneumoniae
Which strains of Klebsiella are resistant to Carbapenem?
Klebisella is gram _______
negative
Klebsiella has what type of antigen?
Somatic O antigen aka has LPS
Is Klebsiella a lactose fermentor or lactose nonfermentor?
Lactose fermentor.
Klebsiella
Highly mucoid colony due to very
thick capsule
Decribe Klebsiella’s motility.
Non-motile (no flagella) (unlike Enterobacter)
Thus, do not have flagella or H antigen
Does Klebsiella produce H2S gas?
No
Is Klebsiella urease positive or negative?
Urease positive, unlike enterobacter
How many different O antigens/serotypes does Klebsiella have?
8 to 11
How many different K antigens or K serotypes does Klebsiella have?
Capsule
Two K. pneumoniae types by the size of their capsule
- Classical K. pneumoniae (top) vs.
- hypercapsulated hypervirulent (bottom) K. pneumoniae strains
Hypervirulent vs. classical K. pneumoniae identification by string test on the bases of mucoid polysaccharide capsule
Name the major virulence factors of Klebsiella
What is the activity of capsular (slime layer)?
Evade phagocytosis and immune evasion
What is the activity of lipopolysaccharides?
Evade serum killing factors & phagocytosis (endotoxin)
What is the activity of adherence factors (type 1 fimbrae)?
Adhere to host surfaces & for conjugative plasmid exchange
What is the activity of biofilms?
Survive in harsh environment
What is the activity of outer membrane proteins?
Protect bacteria from the effect of antimicrobials
What is the activity of siderophores?
Rob iron from the host cell
What is the activity of urease?
Allow growth in urinary tracts
What is the activity of colbactin?
Interfere with the host cell cycle, DNA damage or may cause colorectal cancer
What is the activity of plasmis
multidrug resistance
Why is Klebsiella super resistant to diverse antimicrobials?
Klebsiella contains 5 plasmids 1. pKPN3,
2. pKPN4,
3. pKPN5,
4. pKPN6
5. pKPN7
Plasmids sit inside cytoplasm.
Carry AMR gene (plasmids listed below) and toxins.
Very resistant to antimicrobials because of this.
Name the habitats and sources of Klebsiella
1.
mouth, skin, vulva, teats, & colon of vertebrates & human bowel and respiratory tract of humans and animals
2.
found in feces, soil, water and sewag
Klebsiella is abundant on ?
dairy farm and dairy cows
How is Klebsiella transmitted
- All from own flora
- Oral-fecal route for entry and exit
Food of animal or plant origin or water.
Need to manage food hygiene.
Most Klebsiella infections are caused by two Klebsiella spp.
Klebsiella pneumoniae
pneumonia,
mastitis
Klebsiella oxytoca
colitis,
sepsis,
mastitis
Klebsiella is mostly found in hospital settings
Diseases caused by Klebsiella involve ?
three tubular tracts and beyond
Ulcerative colitis
urinary tract infections
notably pneumonia
mastitis
septicemia
Liver abcess
meningtisi
Klebsiella pneuoniae causes?
Pneumonia
Infiltrates the bronchi, bronchiole
Its name derived from the disease it causes i.e. pneumonia
Klebsiella causes liver abcesses in humans and beef cattle.
How do you isolate, identify, and diagnose methods of Klebsiella
What are the two medically important Enterobacter?
- Enterobacter cloacae
- Enterobacter sakazakii
- Enterobacter aerogenes (now become Klebsiella aerogenes)
Which enterobacter species often exhibit MDR?
Enterobacter cloacae
What is the new name of Enterobacter sakazakii?
Cronobacter sabazaki
Which Enterobacter species contaminates infant powder?
Enterobacter sakazakii
Contaminate infant powdered formula causing enteroclotisis, sepsis,, meningitis.
Enterobacter is a member of _______ bacteria within ___________
coliform, Enterobacteriaceae
What are the unique characteristics of Enterobacter?
Unique characteristics Lactose fermenter
Motile by means of peritrichous flagella Urease negative (like Salmonella)
What culture media can be used to isolate and identify Enterobacter?
- MacConkey agar * Blood agar
What happens when you grow Enterobacter on blood agar?
When grown on blood agar, Enterobacter spp. have been found to have a fecal odor.
Describe the habitat of Enterobacter
Human & animal reservoirs and hospital-acquired infections
* Digestive tracts of animal hosts (vertebrates and invertebrates),
* vulva, and
* oral cavity
* Clinical/hospital environments and patients, health care staff equipment, such as probes, catheters, etc.
* home and industrial environments
* foods
* water, sewage, soil, plants, animal feces
List the virulence factors of Enterobacter?
- Flagella: for motility, biofilm formation, protein export, and adhesion
- Like Enterobacteriaceae, Enterobacter spp. has different endotoxins
- As a member of Gram-negative bacteria, Enterobacter also has the type III secretion system (TTSS), which is recognized as a pathogenicity factor
- Alpha-hemolysins
- Cytotoxins similar to Shiga-like toxins II, “thiol-activated pore-forming
cytotoxins” - Sidorophores = rob iron from host cells
- Plasmids for multi-drug resistance
Enterobacter cloacae is a member of the ______ group, which contains the major
resistant bacterial pathogen
ESKAPE
Theemergenceofmultidrugresistance(MDR)
* ESBL genes confer resistance to most β-lactam antibiotics e.g. cephalosporins and monobactams.
* blaKPCgenesforresistancetothelast-resortcarbapenems meropenem, imipenem, and ertapenem
What diseases do Enterobacter cause?
Diseases in immunocompromised patients
* urinarytractinfection– ranked the 3rd in the USA
* intra-abdominalinfection
* pneumonia
* bacteremia/septicemia
* wounds
What are the three clinically important species of Citrobacter
Citrobacter spp. include:
1. C. freundii
2. C. koseri
3. C. diversus
Characteristics of Citrobacter
* Gram-_____ ___
* Motile by their ______ ____ (__ antigen)
* ______ fermenter —slowly …. member of ______ bacteria
* Produce ___ gas on TSI agar
* Use _____ as their sole source of carbon
* Urease ______ which is why their name is citrobacter; can convert pH of urine because urease positive
lipopolysacharide
* Antigenic structure: ___, ___, ___ antigens
negative rod, peritrichous flagella, H, Lactose, coliform, H2S, citrate, positive, O, H, K
Citrobacter spp. are continuously excreted with?
feces from humans and animals
Like Enterococcus and Proteus, Citrobacter can be used as ?
fecal material contamination indicator of environment, water, food, feed, etc.
What is the habitat of Citrobacter
- Digestive tracts of animal hosts (vertebrates nad invertebrates)
- vulva, and
- oral cavity
Virulence factors of Citrobacter
- Little is known about the pathogenicity and virulence factors, but believed to have:
adhesins,
motility,
biofilm formation,
immunoavoidance,
toxins &
nutrient/iron acquisition
Citrobacter
Injection of diverse products into host cells (epithelial cells) using:
its syringe (type ___ secretion system)
This promotes intimate _____ of Citrobacter to the manipulated epithelial surface
III, attachment
What are the host ranges of Citrobacter?
- Citrobacter spp. include * C. freundii
- C. koseri
- C. diversus
- Hosts of Citrobacter spp. include: humans (zoonotic)
animals
aquatic species and reptiles (e.g., catfish, rainbow trout, and turtles)
Most dangerous to reptiles and fishes
Citrobacter spp. are rare opportunistic nosocomial bacteria
Citrobacter spp cause
Cause:
enteritis & intra-abdominal sepsis urinary tract infection
endocarditis
pneumonia
brain abscesses
septicemia in neonatal infections with aggressive meningitis, sepsis, multiple abscess in the brain and joints
wound infections
In a rare case causes bulla
Bulla formation on lower leg by Citrobacter koseri
Citrobacter is also reptile diseases
Like Salmonella, Citrobacter is frequently associated with reptiles (turtle) production industry
septicemic cutaneous ulcerative disease in turtles petechiae on the carapace/shell & skin
anorexia,
lethargy, liver necrosis,
Citrobacter – reptile diseases
Septicemic Cutaneous Ulcerative Disease
Citrobacter – reptile diseases
Subcutaneous Abscesses
Citrobacter – fish diseases fish suffering from ulcer disease
Arrow shows the rotten and necrotic muscle
How do you isolate, identify, and diagnose Citrobacter
Summary
* Three spp. of Citrobacter are medically important
* The virulence factors of Citrobacter is not well studied
* They are a major problem of aquatic animals (fish) and reptiles
* In addition to affecting the three tubular tracts of vertebrates and other vital organs,
they also attack the skin of humans (bulla formation) and fishes/reptiles (ulcerative dermatitis)