Top Answer
User Avatar
Wiki User
Answered 2008-05-04 01:16:06

Because the two layers of the cell wall in gram negative cells protect the cytoplasm better than the one layer in gram positive cells.

User Avatar

Your Answer


Still Have Questions?

Related Questions

Why gram negative bacteria more resistant to antibiotics?

Gram negative bacteria have thick wall, made up of lipids and polysaccharides molecules so bacteria has harder time penetrating the wall. This is why gram negative are more resistance to antibiotics such as penicillin.

How do antibiotics work on gram - negative bacteria?

Gram negative bacterial cells have an outer membrane that interferes with antibiotics and drug entry into the cell. The bacteria that are resistant to antibiotics are E. coli, salmonella, shigella, and Yersina. The first three affect the GI tract and the second causes the Black Death. These are resistant to penicillin. So ampicillin and streptomycin are used.

Antibiotics treat what type of infection?

Antibiotics treat bacterial infections (provided the bacteria isn't resistant to the antibiotic). Different antibiotics are required to treat Gram positive and Gram negative bacteria due to their differing structures. They have no effect on viruses.

Why are gram positive bacteria resistant to polymyxin?

Polymixin antibiotics interact with the lipopolysaccharide molecule of Gram negative bacteria. This component forms the outer leaflet of the outer membrane. Gram-positive bacteria do not have an outer membrane or lipopolysaccharide and thus polymixin antibiotics are unable to bind to the cell.

Why might a gram-negative infection be harder to treat than gram-positive infection?

In short, it's because they have a membrane around their cell wall that both increases their toxicity, and makes them more resistant to antibiotics. It makes them more resistant because many antibiotics, such as penicillin, work by destroying the cell walls of bacteria. Because they have an extra membrane around their cell walls, gram negative bacteria have extra protection against the antibiotics.

What types of bacteria do antibiotics kill?

Gram negative and gram positive bacteria.

What antibiotics are made with streptomyces griseus?

S. griseus produces antibiotic, streptomycin, and it is useful against gram negative bacteria. Streptomycin and its relatives are considered reserve antibiotics for resistant bacterial strands because they can be neurotoxic and nephrotoxic.

Why gram positive bacteria typically more resistant that gram negative bacteria to antibiotics that disrupt plasma membranes such as polymyxin B?

Most likely because Gram positive bacteria have a thicker peptidoglycan cell wall in comparison to Gram negative bacterias two thinner cell walls.

Why are antibiotics not effective against infections caused by viruses?

Antibiotics are not effective against viruses because viruses are different from bacteria in every way -- in structure, behavior and in the characteristics they have. Viruses aren't technically living, they're fragments of DNA or RNA. Your question is like asking why water isn't effective in cleaning up oil (virus) when it works on dirt (bacteria). As for the second part of your question: There is variety among bacteria. They are not all the same. There are aerobic, anaerobic, gram-positive, gram-negative, autotrophic, heterotrophic. There 15 phyla of bacteria. A phylum is a scientific classification. The way to attack them depends on their specific characteristics. Wide-spectrum antibiotics work against several types of bacteria that have one or more characteristics in common and narrow-spectrum antibiotics (also called targeted antibiotics) are geared for specific types of bacteria. And as for methicillin-resistant, vancomycin-resistant, Bacitracin-resistant and multidrug-resistant bacteria, the reason why some antibiotics aren't effective is right there in the names. These bacteria have "learned" to develop resistance in the form of plasmids, extra-chromosomal elements, and this is genetically passed on.

Why are gram negative bacteria generally more resistant to chemicals than gram positive bacteria?

Gram negative cells have a impermeable outer membrane

How do you eliminate gram positive bacteria from a mixture of gram positive and gram negative bacteria?

AnswerYou can use a "selective" medium that will inhibit the growth of Gram positive bacteria and only allow Gram negative bacteria to multiply. A medium which is commonly used for this is the McConkey agar which contains a crystal violet strain and allows only Gram negative cultures to grow.You can also eliminate Gram positive bacteria with antibiotics (e.g. ampicillin) provided that they are sensitive and not resistant.

Which Gran Positive or negative which is more serious?

Gram positive bacteria responds to the Gram stain; gram negative bacteria does not. The two bacteria do not respond to the same antibiotics. Right now the most dangerous bacteria is a gram negative bacteria. That could change.

Why are certain gram negative cells more resistant than gram positive?

Gram (-) bacteria have a wider spectrum of antibiotic resistance than Gram (+) bacteria because the Gram (-) bacteria are able to share genes that confer resistance between themselves. Therefore, even though a particular bacterium has never encountered most antibiotics, it carries genes that can be activated to protect it from the antibiotics.

Gram negative bacteria are much more resistant to penicillin because?

Peptidoglycan in Gram-negative bacteria is inaccessible to penicillins because penicillin cannot penetrate the Gram-negative outer membrane.

Why Gram positive bacteria are resistant to the effects of certain drugs that kill gram negative cells?

Gram - and + bacteria differ in the structure of their cell walls. Some antibioitics are better able to cross cell walls of gram - or +, so their resistance to these antibiotics differ.(This is one reason). Of course some antibiotics affect both equally or neither.

How do antibiotics work on gram positive and gram negative bacteria?

008 888888888 8

Why do some antibiotics work better against gram positive then gram negative bacteria?

I believe it is because Gram positive bacteria have a cell wall and some antibiotics, such as penicillin effect the cell wall. Gram negative bacteria do not have cell walls, so penicillin has no effect on these organisms.

Is E. coli resistant to vancomycin?

Yes - Vancomycin works on gram positive bacteria. E. coli is a gram negative bacteria.

How might taking antibioitics also have negative effect on your body?

If antibiotics are overused or used incorrectly there is a chance that the bacteria will become resistant - the antibiotic becomes less effective against that type of bacterium. In most countries outside the U.S. antibiotics are rarely given they are seen as having life long side affects.

What kinds of infection do antibiotics fight?

Antibiotics fight bacterial infections, antibiotics do not fight all bacterial infections however, they generally fight one of two types of bacteria (gram negative and gram positive). Antibiotics have no effect on viral infections or parasites, but they are sometimes prescribed with a viral infection to prevent a bacterial superinfection - when you get a bacterial infection because your immune system was weakened by the viral infection first. Antibiotics have saved more lives than those lost in any war but overusing them or not finishing a course can lead to the evolution of resistant bacteria which can no longer be killed by antibiotics.

Why is it important to distinguish between gram-positive and gram-negative bacteria in diagnosing a bacterial infection?

gram- negative and gram- positive bacteria differ in their response to different antibiotics

Why are gram positive bacteria more heat resistant than gram negative bacteria?

Because of their cell wall which contains more peptidoglycan.

Can antibiotics lead to septic shock if used to treat gram-positive bacterial infections?

No, but it can if it is gram negative bacteria..

Where is the cell membrane located in cells that ave cell walls?

In plants its between the Cell Wall and the cytoplasm. In Gram Positive Bacteria its also between the Cell Wall and the cytoplasm. In Gram Negative Bacteria its between the two membranes. Hope this helps!!

How do gram-positive and negative stains react differently to antibiotics?

The only thing that Gram- and Gram+ have to do with antibiotics is that each stain can give a clue as to which antibiotic might work against the microbe being stained. The outer membrane of Gram-negative microbes prevents antibiotics from entering. Gram-negative bacteria include: E. coli, Salmonella, Shigella, Yersinia. These resistant to penicillin, streptomycin and ampicillin. Most infections due to Gram-positive organisms can be treated with quite a small number of antibiotics. Penicillin, cloxacillin, and erythromycin should be enough to cover 90 per cent of Gram-positive infections.