2. Properties of Enterobacteriaceae
Found in intestines of humans and animals
G+C ration is 39-59%
Phylogenetically closely related
Type genus is Escherichia coli
Gram-negative facultative anaerobic rods
Motile except Shigella and Klebsiella
Optimum Temp 35oC-37oC
Fermentation prefered:
Oxidation-reduction of glucose anaerobicaly generating
alcohols, acids, CO2 gas
Oxidase negative, Catalase positive
Nitrate is reduced
extract oxygen from NO3 reducing it to (NO2)
5. Types of E. coli
Enteropathogenic E.coli (EPEC)
Entrotoxigenic E. coli (ETEC)
E. coli enteroinvasive (EIEC)
E. coli enterohemmoragic (EHEC
O157:H7, Humpergur
E. coli enteroaggregative (EAEC)
6. Diagnostics
EnteroScreen 4™single test for non-lactose-fermenting, oxidase-negative, enteric pathogens
Lys deNH3
H2S
Lys
decooHase
Urease
7. MacConkey Agar and Eosin Methylene Blue (EMB) agar
both are:
Differential medium for lactose fermentation
Differentiates lactose fermenters and non-fermenters
Selective medium
Selects enteric gram negatives and Inhibit gram positives
Specimens: Feces,, sputum, urine, wound, peritoneal
flulids: MAC or EMB
EMB MacConkey
9. Biochemical tests
Indole, Methyl Red, Voges-Prosakaur, Citrate (IMViC)
Tests detects:
Glucose fermentation resulting in mix-acids
OR neutral pathways producing Acetoin
Citrate and urease utiliztions
Most tests are included in recent technologies like API,
Vitek,
10. Advanced Identification kits
1. ABI kit
2. Vitec Kits:
All media or antibiotics are tested in this card
And the computer reads out the card after 8-12 hours
Card
12. P. aeruginosa
Clinical Diseases
Infection of wounds and burns (blue-green pus).
Skin and nail infections
Pulmonary infection
Necrotizing pneumonia in Cystic Fibrosis patients
Eye infections: corneal ulcer.
Ear infections
Otitis externa: swimmers
Endocarditis
Urinary tract infection
13. P. aeruginosa
Forms fluorescent greenish colonies, sweet
odor, and b-hemolysis.
•Pyocyanin- nonfluorescent bluish pigment;
•pyoverdin- fluorescent greenish pigment;
•pyorubin, and pyomelanin
•Some strains have a polysaccharide capsule.
•Identification of P. aeruginosa is usually based on
colonial morphology, b-hemolysis, oxidase
positivity, the presence of characteristic pigments
and sweet odor, and growth at 42 oC.
14. Brucellosis: Brucella spp.
1887 by Dr. David Bruce.
Zoonotic disease
Transmitted by animals and their products
Gram negative, coccobacilli bacteria
Facultative, intracellular organism
Environmental persistence
Temperature, pH, humidity
Frozen and aborted materials
15. Brucella: Properties
Highly contagious zoonotic disease
Also known as undulant fever(intermittent), Malta fever,
Gibraltar fever, Bang's disease, or Mediterranean fever,
Brucellosis mostly is occur in people who work with livestock
It is an intracellular parasite, and can be congenital
Zoonotic Species in animals
B. abortus in cattle
B. suis in hogs
B. melitensis in goats and sheep
Symptoms :intermittent fever, sweating, chills, aches, and
mental depression.
16. Diagnosis in Humans
Isolation of organism
Blood, bone marrow, other tissues
Serum agglutination test
Four-fold or greater rise in titer
Samples 2 weeks apart
Immunofluorescence
Organism in clinical specimens
PCR
Treatment
tetracyclines (with streptomycin), co-trimoxazole, and
sulfonamides, is effective. Bed rest is also imperative
Center for Food Security and Public Health, Iowa State University, 2008
17. Bordetella pertussis: Whooping Cough Well known
Infects only man, (child hood disease)
Aerobic, Gram negative coccobacilli
highly communicable through Respiratory tract Whooping
cough. Produce endotoxin, pertusis toxin
Three stages of disease
Catarrhal: runny nose, low fever, and mild cough 1-2wks
Paroxysmal stage: repetitive coughing 1-6 wks
Convalescent stage: final, weeks to months
Diagnosis
Isolation, PCR, direct fluorescent antibody, and serology
Treatment
Erythromycin, Azithromycin, and clarithromycin
Vaccine: part of regular vaccination schedule (See tetanus, DTP)
18. Haemophilus Spp (Blood/heme loving)
Small, nonmotile, pleomorphic, Gram negative, coccobacilli, obligate
parasites of man and animals
Isolated in an influenza Pandemic 1890 and was mistakenly considered
the cause of influenza until Influenza virus was confirmed. Contrary to
what the name suggests, the bacterium does not cause influenza
Occurs in two forms virulent capsulated and noncapsulated
Aerobic, could be facultative anaerobic, fastidious require X factor
(i.e., hemin) and V factor (NAD or NADP)to grow
chocolate blood agar which is prepared by adding blood to an agar base at
80oC. The heat releases X and V factors from the RBCs and turns the
medium a chocolate brown color.
H. Influenza type b is the major pathogen (95% of human disease)
Man and animals are only natural hosts, highly adapted to man
H. Ducreyi
STD (soft chancroid) not common
Opportunistic pathogens with uncommon or rare infections include:
H. Aphrophilus, H. Parapgrophilus, H. Parainfluenza, H. haemolyticus, H.
Parahemolyticus, H. segnis
19. H. Influenza have
no specific
syndrome but can
cause:
meningitis,
conjunctivitis,
sinusitis, cellulitis,
otitis, epiglottitis,
pneumonia,
Health Canada and www.cdc.gov/vaccines/pubs
20. According to WHO 3 million serious illnesses, 386 000 deaths
uder age of 5, per year by meningitis and pneumonia
Important secondary invader to influenza virus
In swine influenza in pigs, association between the virus and
Haemophilus suis is necessary for the disease.
Similar association between human influenza virus and H.
influenzae seen in chick embryos and infant rats.
The fight between Streptococcus pneumoniae
In vitro Strep pneumoniae wins
In vivo H. Influenza wins
In vivo H. Influenza signals host immune system against S.
pneumoniae, the former is not well affected
21. One of the most transformable genomes: First genome
1995
H. Influenza was the first free living organism to have the
complete genome sequenced in 1995 by The Institute for Genomic
Research (TIGR) now the J. Craig Venter Institute
Why is it highly adapted
Transformable by many ways, by first making “blebs” in outer
membrane
The genome consists of 1,830,140 base pairs of DNA in a single
circular chromosome that contains 1740 protein-coding genes, 58
transfer RNA genes tRNA, and 18 other RNA genes. The sequencing
method used is whole-genome shotgun, which was completed and
published in Science in 1995 and conducted at The Institute for
Genomic Research.[12
22. Diagnosis
Microscopy to detect in CSF, synovial fluids,
Culturing, difficult, may be not sensitive
latex particle agglutination test (LAT)
PCR
23. cefotaxime , ceftriaxone, ampicillin and
sulbactam, cephalosporins of the second and third
generation, or fluoroquinolones are preferred.
Hib conjugate vaccine
Hib is preventable, The two major obstacles to prevention
of Hib disease are a shortage of information and a shortage
of money
Shortage of info: difficult to diagnose, it causes death without
being recognized
Hib vaccine is expensive in 2005, it costs roughly seven times
the total cost of vaccines against
measles, polio, tuberculosis, diphtheria, tetanus, and
pertussis.
24. H.influenza: Hidden disease, diagnostics, and treatment dilema. How Hib
goes undergound
Does not cause a unique disease syndrome, but deadly forms are
pneumonia and meningitis
But other bacteria also cause pneumonia and meningitis
Doctors respond first with Antibiotics to childhood pneumonia or
meningitis
However, to confirm a case of Hib samples must be taken:
a blood specimen in the case of pneumonia,
a spinal-fluid specimen by lumbar puncture in the case of meningitis
and the bacteria must then be isolated from those specimens in a
laboratory...a challenge even for sophisticated laboratories
In developing countries, these tests may not be made at all, or laboratories
may fail to carry them out correctly, or Hib's presence may be masked
because antibiotics were given before the samples were taken
The hidden nature of Hib...this is how Hib is underestimated
A "Rapid Assessment Tool" has been developed by WHO and
CDC to make sensible estimates of Hib
