top 3 favourite bacteria

8/8/2019 Top 3 Favourite Bacteria

1/15

Top 3 Favourite Bacteria

Mohd Saufi bin Mohd Azehar

IES080034


2/15

Streptococcus lactis

A gram-positive bacteria

A bacterial species found commonly as a

contaminant in milk and dairy products A common cause of souring and coagulation

of milk

Some strains produce nisin, a powerfulantibiotic that inhibits growth of many other

gram-positive microorganisms


3/15

Used to make buttermilk

Buttermilk is used for baking as wellas drinking. It makes pancakes,waffles,and cakes rise very well

Streptococcus lactis ferments the

lactose in milk to lactic acid. Theacidic pH causes the protein in milk(most prominently casein) toprecipitate, thickening the liquid

Buttermilk should cause less of aproblem for those who are lactoseintolerant because some of thelactose has been broken down tolactic acid


4/15

Streptococcus lactis

Gram stain of buttermilk (1000x), showing

Streptococcus lactis (purple)

with a pink background of milk protein

(casein)

LA(Luria Agar) plate streaked

with Streptococcus lactis and

incubated at 37C for 24 hours; top

view


5/15

Vibrio fischeri

Luminous, Gram-negative, marine

heterotroph

Family Vibrionaceae

Can be found throughout the

world in temperate andsubtropical regions


6/15

Symbiosis ofVibrio fischeri

and the Hawaiian squid,Euprymna scolopes

The squid camouflages itselfby projecting light downwardfrom its light organ. Inside thelight organ are luminescentbacteria, Vibrio fischeri, that

produce the light Housed in the squid's mantle

cavity


7/15

The squid provide Vibrio fischeriwith shelter

and a stable source of nutrients The ability ofVibrio fischericells to produce

bioluminescence results from the expressionof the luxoperon

Expression of luminescence is dependent oncell density and thus light is not seen unlessthe bacteria are in high concentration, like inlight emitting organs of fish and squid

This phenomenon is known as quorumsensing


8/15

Pseudomonas aeruginosa

A gram-negative bacteria

Rod-shaped bacteria

Belongs to the family Pseudomonadaceae

Widespread in nature, inhabiting soil, water,plants, and animals

P. aeruginosa secretes a variety of pigments:

-pyocyanin (blue-green)-fluorescein (yellow-green and fluorescent)

-pyorubin (red-brown)


9/15


10/15

This bacterium can be found on the skin ofhumans and not cause disease, perhaps we

would call it a commensial, but if the person hasa severe burn P. aeruginosa can cause aninfection and becomes a pathogen. This type oforganism is called an opportunistic pathogen

It is the most common pathogen isolated frompatients who have been hospitalized longer than1 week

It is a frequent cause of nosocomial infections

such as pneumonia, urinary tract infections(UTIs), and bacteremia. Pseudomonal infectionsare complicated and can be life threatening


11/15

Invasive burn wound

infection implies thatbacteria or fungi

proliferating in burn

eschar are invading

the underlying viabletissues. These wounds

display a change in

color, new drainage,

and, commonly, a foulodor. This infection

can be life threatening


12/15

Management of burn blisters is controversial. Many can be left

intact to facilitate comfort, while the underlying wound heals.

Sometimes, blisters obscure full-thickness wounds, as shown

here, but, usually, wounds underlying blisters are partialthickness


13/15

Escharotomy to release the chest wall and allow for

ventilation of the patient


14/15

Splinting a serious hand burn


15/15

top 3 favourite bacteria

Documents