Microbiology and Immunology

Coryneform bacteria WORLD OF MICROBIOLOGY AND IMMUNOLOGY

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With respect to contamination of food, the hygieneof

food handlers is a key factor. In the United States, estimates

are the one in five food-borne disease outbreaks is caused by

the handling of foods by personnel whose hands are contami-

nated with bacteria or viruses. Poor hand washing following

use of the bathroom is the main problem.

In the nineteenth century, similar hygiene problems cre-

ated a death rate in most surgical procedures. The contamination

of open wounds, incisions and entry routes of catheters killed

the majority of surgical patients. With the adoption of sterile

operating room technique and scrupulous personnel hygiene,

the death rate from surgical procedures is now very low.

See alsoBlood borne infections; Hazard Analysis and Critical

Point Program (HAACP); History of public health;

Transmission of pathogens

CCoryneform bacteriaORYNEFORM BACTERIA

Coryneform bacteriaare normal residents of the skin. They

can also cause opportunistic infections. These are infections

that occur as a secondary infection, when the immune

response of a host has been weakened by another infection or

by another insult to the immune system, such as chemother-

apy. An example is Corynebacterium jeikeium, whose infec-

tion can be taxing to treat as the organism is resistant to

numerous antibiotics. Over the past two decades, the numbers

of such infections have been rising. This may be an indication

of an immune stress on the body.

Coryneform bacteria can stain positive in the Gram

stain protocol. However, this reaction is not consistent. A char-

acteristic feature is their tendency to arrange themselves in a

V-like pattern or lined up, much like logs stacked one against

the other.

While there are some consistencies among the members

of the Coryneform bacteria, a hallmark of these bacteria is

their diversity of habitats. This, and their inconsistent Gram

stain reaction, can make identification of the microorganism

tedious. More rigorous biochemical and molecular biological

tools of identification are being used by organizations such as

the Centers for Disease Control(CDC) to establish a definitive

classification scheme for Coryneform bacteria. For example,

CDC groups JK and D-2 in the genus Corynebacteriumare

now recognized as important human disease-causing microor-

ganisms. Conversely, these rigorous techniques have resulted

in the removal of some species of bacteria from the genus.

Coryneform bacteria are important medically.

Corynebacterium diphtheriaeis the organism that causes

diphtheria. In fact, before Coryneform bacteria were known to

Typical anti-contamination garb worn during a surgical procedure.

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