Microbiology video 22:Coliforms

How to do differentiation when from gram negatives

- Inoculate regularly Mac agar -and inoculate another Mac agar that contains carbohydrate sorbitol.

These are found in______

- Red pigment colonies. Intestinal tract.. Seretia marsan is an opportunist pathogen, it gets easily on immune in compromised people.

Characteristics of Seretia marsan.

- opportunist pathogen - it can cause pneumonia -UTI - wound infections - very resistant to antibiotics

Diseases that Klebsiella pneumonia can cause is

- pneumonia : in blood stream which is blood in sputum. - UTI infections- Wound infection.

Klebsiella pneumonia

-A coliform - g=r - pink on Mac agar - A large mucoid colony because it produces a capsule. - Resistant to antibiotics along with the fact that it is a CRE - carbapenem Resistant Enterobacteriacae . carbapenem is an antibiotics which is reserved for serious gram negative rod bacteria. Bacteria make an enzyme know as carpenemyze in order to be resistant to CRE

Coliform is

-G=r -Lac fermentation positive - normal flora in the colon of man and animals.

After getting a clear colonies on Mac with sorbitol, what next step will you take

-Identify Mac with sorbitol with clear colony as E. coli 0157: H7 - then test for 0 and H antigen.

Clear colonies on Mac with sorbitol

-Identify clear colonies as E. coli but if it is not Ecoli you're done. - look specifically for O antigen and it has to be 0157 and H antigen has to be 7. I.e Test for O &H antigen.

Causes of Seretia marsan

-Pneumonia. - UTI. - wound infection -it is very resistant to antibiotics

Enterobacter sakazakii- Cronobacter sakazakii

. -Supper resistant to antibiotic antibiotics. - carbapenem resistance . -it is a CRE

Enterobacteriacae is divided into

1. Coliforms. 2. Non coliforms. 3. True pathogen

List of coliforms

1. E. coli 0157: H7 2. Klebsiella pneumonia 3. Serretia marsans 4. Cronobacter sakazakii

coliforms include

Escherichia coli and other gram-negative normal enteric microbiota that ferment lac- tose rapidly (within 48 hours).

The color change on Maconkey agar happen based on what reaction?

Fermentation of lactose. Lactose is a carbohydrate-sugar. So when bacteria metabolise carbohydrate we get acid producers as end product.

What is a serious complication of 0157 :H7

HUS syndromes

Maconkey agar with sorbitol

Hardy diagnostics Maconkey agar with sabitol is used as selective and differential medium for the detection of E.coli 0157:H7

When was this kind of E.coli first discorvered

In 1982 in hamburger fast food place and it caused several deaths

Where is E. coli 0157 :H7 found as a normal flora

In the Colon of beef, and deer. Animals

We do not treaty 0157 :H7 with antibiotics because

It produces toxins and it worsens the condition

Members of the Enterobacteriacae are the number one causative organisms of _____

Nauseocomia infections more so as staph aureus.

Are all pink colony on Maconkey coliforms?

No, because coliform is g=r; lactose fermentation positive, normal flora in the colon of man and animal. E.coli 0157 :H7 is still a coliform but it's not. A normal flora in humans. You cannot differentiate the color on Maconkey agar. They're all g=r.

Non coliform are

Non- lactose-fermenting or slow lactose-fermenting bacteria that are either normal microbiota or regular pathogens.

Maconkey agar is what kind of media

Selective for g=r, and differential. The color change is based on fermentation of lactose. Remember lactose is a carbohydrate.

0157 :H7 can produce what toxins

Shigatoxin also refers to as exotoxin and this causes death to the cell, inhibits proteins synthesis. It also can infect other cells and lyse red blood cells which gives the glugging of the kidney which causes kidney failure and death.

The only difference between sorbitol Mac agar and the regular Mac agar is

The carbohydrate in sorbitol Mac agar is not lactose but it is SORBITOL. Remember sorbitol is also a carbohydrate which means sugar.

It is not a normal flora in humans

True

Human get this kind of E. coli how

When we eat improperly cooked hamburgers or drink unpasteurized milk or fruit juices.

What is the infectious dose of 0157 :H7

10 organisms. We should cook our food more properly to avoid this number of organisms which can cause death

Seretia marrsans

1n 1949-1968 Seretia marsan was intentionally released in the air because the wanted to see the effect on people and it was seen as an opportunistic pathogens, very deadly

________ does not ferment sorbitol

E.coli 0157 :H7 does not ferment sorbitol. Sorbitol negative is clear colonies on Mac with sorbitol.

The Family Enterobacteriaceae is traditionally divided into two subcategories

coliforms and Noncoliforms