Microbiology B‑class Mid‑importance

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Gram-staining characteristics are used for clinical as well as taxonomic purposes, and specific examples relating to specific pathogens should probably be retained. -- Someone else 23:22 May 1, 2003 (UTC)

Gram-staining is useful clinically primarily because it places limits on what group a bacterium belongs to, and is only one of several tools necessary to identify a pathogen. I don't think we should try and make this page into a full guide for identifying gram-negative bacteria, and while certainly some examples are helpful, the amount given on the page is overkill. Really, how critical is it to mention Bdellovibrio, as opposed to the hundreds of other gram-negative genera that could be listed here?

I get the strong impression that the list was primarily there as a way of linking to pages on specific bacteria, which otherwise would be orphans. Relatively unimportant bacteria that belong to larger groups, though, can be linked from those groups. Saying that proteobacteria are gram-negative and the acetic acid bacteria are proteobacteria tells me that acetic acid bacteria are gram-negative, and more. I don't see the reason for giving examples beyond better-known examples like Escherichia coli and Salmonella.

I agree that the page needn't enumerate all gram-negative bacteria. On the other hand, if there's an article on any particular one, why not list it? My point is that someone examining a specimen categorizes a given bacteria as gram-negative or gram-positive, without necessarily further explicitly classifying them (e.g. "It's gram-positive cocci in chains, must be strep" vs "It's gram-positive cocci in chains, probably a Firmacute". Some notable human gram-negative pathogens like shigella, H. influenzae, Yersinia, Klebsiella' and Vibrio vulnificus could be explicitly added: I guess I'm just suggesting that the clinical names that are used be present in addition to any higher taxonomic classifications. -- Someone else 00:31 May 2, 2003 (UTC)

I HAVE NO IDEA WHAT THIS ARTICLE IS ABOUT. IF I'M LOOKING UP A SCIENCE TERM ON WIKIPEDIA IT'S BECAUSE I'M NOT A SCIENTIST. THIS ARTICLE DOESN'T SAY ANYTHING IN PLAIN ENGLISH. SOMEBODY PLEASE EDIT IT!!

I heard that gram-negative bacteria are harder to kill than gram-positive bacteria. Is this true, and why? If it's true, I think this could be added to the article. authraw 01:09, 25 February 2006 (UTC)[reply]

No, it's not really true. More precisely, it isn't possible to make that broad a generalization without a laundry list of exceptions. For example, two common yet extraordinarily difficult to treat pathogenic organisms - Staphylococcus aureus and Enterococcus faecalis - are both Gram-positives. MarcoTolo 03:37, 25 February 2006 (UTC)[reply]

THIS ARTICLE IS USELESS. IT TELLS ME WHY THEY'RE CALLED GRAM-NEGATIVE BUT NOT WHY IT'S A CATEGORY OR WHY THERE'S A GRAM TEST IN THE FIRST PLACE. IF I'M LOOKING UP SCIENCE TERMS ON WIKIPEDIA, I THINK WE CAN SAFELY ASSUME I'M NOT A SCIENTIST.

I think this section should make clear if these characteristics are shown in all gram-negative bacteria, whether they are just more common in gram-negative than gram-positive bacteria, or whether they are characteristics that might lead to a bacteria taking up the dye. At the moment I don't know which is correct. Djr36 23:03, 30 May 2006 (UTC)[reply]

To know the total viable count, we are using plate count agar. After getting the TVC value (which is very low i.e. 10) we are taking out the colony from TVC plate and doing GRAM staining. Then we are getting Gram negetive bacteria invariably. Please let me know, if Gram negetive is totaly unaccepatble for the product to be used directly in contact with the skin ? I understand the TVC value is very good and still if I am getting it GM -ve, is it at all objectionable ? —Preceding unsigned comment added by Ayan1970 (talk • contribs) 07:34, 15 May 2009 (UTC)[reply]

I'm not at all familiar with microbiology and I ended up here through a series of tangents, which often happens when I read wikipedia. Anyway, after reading this article I felt that an important question was left unanswered; what is it about the structure of gram-negative cell walls that causes it to be found commonly in pathogenic bacteria?

If there is a strong correlation between this cell wall type and pathogenesis, then it begs for at least a brief explanation. The short answer from a friend (who is a periodontist, not a microbiologist), is that the cell wall is highly insoluble and therefor more resistant to phagocytosis.

That's all I felt the article was lacking. If someone would be kind enough to elaborate, I would appreciate it.

THIS PERSON IS MORE PATIENT THAN I AM. I'M TIRED OF READING WIKIPEDIA ARTICLES ON SCIENCE TOPICS THAT ARE NOT IN PLAIN ENGLISH. IT'S SAFE TO SAY THAT IF A PERSON IS LOOKING UP A SCIENCE TERM ON WIKIPEDIA THEY ARE NOT A SCIENTIST!! IF I WERE I WOULD (A) KNOW THIS ALREADY, OR (B) BE LOOKING IT UP IN A SPECIALIZED SOURCE. THE QUESTION IS, WHAT TO AN AVERAGE PERSON, IS A GRAM-NEGATIVE BACTERIA? NOT HOW DID IT GET ITS NAME, WHAT PROTEINS ARE IN IT, ETC.

12.190.32.3 02:11, 14 July 2006 (UTC) Thanks, Galen Matson[reply]

I recently created a new [| Gram negative bacteria] also did [Gram positive bacteria] I figured it would be usefull if we put all of the bacteria into these categories on wikipedia mentioning it here so those categories can be populated

I added a link from the article to the category. A category sounds like a good way to address the concerns under Old Discussions about how many bacteria to discuss here. JeremiahJohnson (talk) 06:13, 27 June 2008 (UTC)[reply]

As on the Gram-positive page, it would be nice to have a microscope image of some stained bacteria. Asd28 02:57, 22 July 2007 (UTC)[reply]

Excellent point - image from WP Commons added. -- MarcoTolo 03:13, 22 July 2007 (UTC)[reply]

I believe campylobacter is oxidase positive, not oxidase negative as in the picture —Preceding unsigned comment added by 71.67.122.124 (talk) 02:03, 15 April 2010 (UTC)[reply]

Agreed, Campylobacter is oxidase positive, contrary to what the image shows. As well as Helicobacter — Preceding unsigned comment added by Jcsjohnson (talk • contribs) 23:03, 30 November 2011 (UTC)[reply]

There seems to be a disconnect between the two images showing the cell wall structures. One image (the large, detailed) shows a single periplasmic space; whereas, the other image (the one comparing Gram-positive and Gram-negative structures) shows two periplasmic spaces. They seem to contradict each other. Jdevola (talk) 01:29, 8 April 2012 (UTC)[reply]

I removed "Crenarchaeota: Unique because most bacteria have gram-positive molecules in their capsules, it has gram-negative." as not only it is terribly wrong, but it makes no grammatical sense! Some Archaea do react to gram stains, but they still remain Archaea. —Preceding unsigned comment added by Squidonius (talk • contribs) 22:57, 24 January 2008 (UTC)[reply]

Can you explain me, in a TVC plate if TVC value is well within below 100, then presence of gm -ve is too serios or the gm +ve ? If there we find Gram negetive, what to conclude. How to kill Gram negetive Aeromonas ? Thanks AYAN —Preceding unsigned comment added by Ayan1970 (talk • contribs) 07:43, 15 May 2009 (UTC)[reply]

I want to propose a change in the "Gram related" articles. According to several sources I've looked at, "Gram" is capitalized only if it begins a sentence or if they directly refer to a proper noun (e.g. Gram's method, gram-negative, gram-positive). The articles are inconsistent with capitalization and I want to go through fix them. richard.decal (talk) 00:55, 11 August 2010 (UTC)[reply]

Since the name Gram comes from the name of an actual person, I believe that Gram should always be capitalized when it refers to the method named after the person, Gram (just as Southern blot is capitalized). Jdevola (talk) 01:24, 8 April 2012 (UTC)[reply]

At "Characteristics" it says: "Thin peptidoglycan layer (which is much thinner than in not Gram-positive bacteria)". Should that be "than in not Gram-positive bacteria" or "than in non Gram-negative bacteria" ? Jagdfeld (talk) 11:42, 11 August 2010 (UTC)[reply]

Right now the introducing definition is "Gram-negative bacteria are those bacteria that do not retain crystal violet dye in the Gram staining protocol.[1]", [1] refering to an article that states nothing about the definition. This sound like a strange definition and if this really is the true definition, it should be clearly stated why they are coloured in contrast to gram-positive bacteria. Does anyone have a reliable source on what definition we should go for? 83.233.145.84 (talk) 20:53, 22 September 2010 (UTC) This is covered at http://www.horizonpress.com/gateway/gram-negative-bacteria.html as follows: In microbiology, the visualization of bacteria at the microscopic level is facilitated by the use of stains, which react with components present in some cells but not others. This technique is used to classify bacteria as either Gram-positive or Gram-negative depending on their colour following a specific staining procedure originally developed by Hans Christian Gram. Gram-positive bacteria appear dark blue or violet due to the crystal violet stain following the Gram stain procedure; Gram-negative bacteria, which cannot retain the crystal violet stain, appear red or pink due to the counterstain (usually safranin). The reason bacteria are either Gram-positive or Gram-negative is due to the structure of their cell envelope. (The cell envelope is defined as the cell membrane and cell wall plus an outer membrane, if one is present.) Gram-positive bacteria, for example, retain the crystal violet due to the amount of peptidoglycan in the cell wall. It can be said therefore that the Gram-stain procedure separates bacteria into two broad categories based on structural differences in the cell envelope. — Preceding unsigned comment added by 81.157.20.189 (talk) 15:27, 13 July 2012 (UTC)[reply]

The introduction is too jargon-y and needs to have more of an eye on its audience. Why do most people come to the Gram-negative bacteria page? I can't say for sure, but I'd bet they're looking for information about the relationship between this bit of information and real-world application, most notably in the context of antibiotics.

The details are important, but they're meaningless without context. As in, "how does this fit outside of the academic systemization of everything?" — Preceding unsigned comment added by 68.33.60.211 (talk) 14:59, 28 December 2013 (UTC)[reply]

Standard form used by the US Federal Government's Center for Disease Control is as follows: [1]

gram

Gram should be capitalized and never hyphenated when used as Gram stain; gram negative and gram positive should be lowercase and only hyphenated when used as a unit modifier.

• Gram staining
• gram negative
• gram-positive bacteria

It would be helpful for this article, Gram-positive bacteria, and Gram staining to be standardized accordingly. Wikiuser100 (talk) 15:02, 17 March 2014 (UTC)[reply]

I lowercased gram-negative and gram-positive in their articles. Lowercasing is the style used by various medical dictionaries (e.g., Dorland's, M-W Medical, Taber's), AMA style, and others. As for whether the hyphen is treated as invariable across attributive and predicative positions, major styles such as AMA style treat them as permanent compounds, not temporary compounds, and thus hyphenate in both positions, because they are entered as headwords in medical dictionaries. The style in which the compound is styled openly in predicative position is treating the compound as a temporary compound, which is fine, but sometimes it comes simply from a resident editor who knows the general norm about temporary compounds (hyphenated attributive, open predicative) but is unaware of how the treatment of permanent compounds cascades over that. Quercus solaris (talk) 23:28, 11 June 2014 (UTC)[reply]

hey Quercus solaris On the face of it, it appears that this edit where you added "The adjectives gram-positive and gram-negative are conventionally lowercase in medical editing (as explained at Eponym > Capitalized versus lowercase.", is directed to people who might want to edit our article and change the capitalization. Is that true? If so, that makes sense, but they should be "invisible comments" as described here. If they are meant as part of the content, to inform readers about gram-negative bacteria themselves, then a) it needs to be somewhere in the body (nothing belongs in the lead that is not in the body, as per WP:LEAD) but b) I am not sure this is important enough to include in the article at all, much less in lead. Please clarify what the purpose of this is. Thanks. Jytdog (talk) 11:25, 11 June 2014 (UTC)[reply]

Hi. It's meant to serve as part of readers' education generally. The person in mind is the science student who is learning about this topic and has a natural question about the way the word is written (why isn't it capitalized like eponyms usually are?). In that sense it's about education, not "mere how-to". Although I agree that it "doesn't matter" in the sense that it's irrelevant to the biology, it's relevant in that it answers a question that an observant student may well ask. I agree that it doesn't need to be in the lede. Someone who wants that answer can bother to look for it within the article body. I will move it down. Quercus solaris (talk) 14:44, 11 June 2014 (UTC)[reply]

that may be OK, but you need a reliable source about how "gram negative" and "gram positive" are spelled in the real world. What wikipedia's guidelines are, is germane only to wikipedia editing. If you cannot supply a reliable source, we will need to delete this content. Jytdog (talk) 15:35, 11 June 2014 (UTC)[reply]

btw, your pointing readers to Wikipedia's editing guideline is why I thought this might be a note for editors, as opposed to general content.Jytdog (talk) 15:39, 11 June 2014 (UTC)[reply]

The link is not to Wikipedia's editing guidelines (which would be WP:MOS and its various sections). It is to the article on eponyms, in the section where it talks about how dictionaries style eponymous terms. Medical dictionaries (Dorland's, M-W Medical, Taber's, and others) style these adjectives lowercase (as they also do with parkinsonian, haversian, fallopian, and eustachian). I added citations. Quercus solaris (talk) 23:10, 11 June 2014 (UTC)[reply]