Oxidase test - Revision history

Aidan: Text replacement - " species]]" to "]]"

2022-02-08T02:52:35Z

Text replacement - " species]]" to "]]"

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	==Interpretation==		==Interpretation==
	* All oxidase-positive bacteria are aerobic		* All oxidase-positive bacteria are aerobic
	** '''P''': [[Pseudomonas ~~species~~]]		** '''P''': [[Pseudomonas]]
	** '''V''': [[Vibrio cholerae]]		** '''V''': [[Vibrio cholerae]]
	** '''N''': [[Neisseria ~~species~~]]		** '''N''': [[Neisseria]]
	** '''C''': [[Campylobacter ~~species~~]]		** '''C''': [[Campylobacter]]
	** '''H''': [[Helicobacter ~~species~~]] and [[Haemophilus ~~species~~]]		** '''H''': [[Helicobacter]] and [[Haemophilus]]
	** [[Aeromonas ~~species~~]]		** [[Aeromonas]]

	===Oxidase-Positive Organisms===		===Oxidase-Positive Organisms===

Aidan: /* Oxidase-negative Organisms */

2021-09-05T19:54:55Z

Oxidase-negative Organisms

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	{{#ask: [[Oxidase::positive]] \|?Stain \|?Cellular shape \|?Oxidase }}		{{#ask: [[Oxidase::positive]] \|?Stain \|?Cellular shape \|?Oxidase }}

	===Oxidase-~~negative~~ Organisms===		===Oxidase-Negative Organisms===
	{{#ask: [[Oxidase::negative]] \|?Stain \|?Cellular shape \|?Oxidase }}		{{#ask: [[Oxidase::negative]] \|?Stain \|?Cellular shape \|?Oxidase }}

Aidan at 19:54, 5 September 2021

2021-09-05T19:54:44Z

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			==Background==
	* Identifies '''cytochrome C oxidase''' by testing for the ability to oxidize tetramethyl-p-phenylenediamine to indophenols, which are purple		* Identifies '''cytochrome C oxidase''' by testing for the ability to oxidize tetramethyl-p-phenylenediamine to indophenols, which are purple
	* The test is positive when it turns '''purple''' within 10 seconds		* The test is positive when it turns '''purple''' within 10 seconds
	** Must be done from plain 5% SBA		** Must be done from plain 5% SBA

			==Interpretation==
	* All oxidase-positive bacteria are aerobic		* All oxidase-positive bacteria are aerobic
	** '''P''': [[Pseudomonas species]]		** '''P''': [[Pseudomonas species]]
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	** '''H''': [[Helicobacter species]] and [[Haemophilus species]]		** '''H''': [[Helicobacter species]] and [[Haemophilus species]]
	** [[Aeromonas species]]		** [[Aeromonas species]]

			===Oxidase-Positive Organisms===
			{{#ask: [[Oxidase::positive]] \|?Stain \|?Cellular shape \|?Oxidase }}

			===Oxidase-negative Organisms===
			{{#ask: [[Oxidase::negative]] \|?Stain \|?Cellular shape \|?Oxidase }}

	== Further Reading ==		== Further Reading ==

Aidan: Linkified

2019-10-29T17:34:50Z

Linkified

← Older revision		Revision as of 17:34, 29 October 2019
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	** Must be done from plain 5% SBA		** Must be done from plain 5% SBA
	* All oxidase-positive bacteria are aerobic		* All oxidase-positive bacteria are aerobic
	** '''P''': ''Pseudomonas'' ~~spp.~~		** '''P''': [[Pseudomonas species]]
	** '''V''': ''Vibrio cholerae''		** '''V''': [[Vibrio cholerae]]
			** '''N''': [[Neisseria species]]
	** '''N''': [https://microbeonline.com/neisseria-gonorrhoeae-properties-disease-pathogenesis-and-laboratory-diagnosis/ ''Neisseria''] spp.
	** '''C''': ''Campylobacter'' ~~spp.~~		** '''C''': [[Campylobacter species]]
	** '''H''': ''Helicobacter'' ~~spp.~~ / ''Haemophilus'' ~~spp.~~		** '''H''': [[Helicobacter species]] and [[Haemophilus species]]
	** ''Aeromonas'' ~~spp.~~		** [[Aeromonas species]]

	== Further Reading ==		== Further Reading ==

Aidan: Summarized

2019-10-29T17:33:55Z

Summarized

← Older revision		Revision as of 17:33, 29 October 2019
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			* Identifies '''cytochrome C oxidase''' by testing for the ability to oxidize tetramethyl-p-phenylenediamine to indophenols, which are purple
⚫	~~Source:~~ [https://microbeonline.com/oxidase-test-principle-procedure-and-oxidase-positive-organisms/ ~~microbonline.com~~]
			* The test is positive when it turns '''purple''' within 10 seconds
			** Must be done from plain 5% SBA
			* All oxidase-positive bacteria are aerobic
		⚫	** '''P''': ''Pseudomonas'' spp.
		⚫	** '''V''': ''Vibrio cholerae''
		⚫	** '''N''': [https://microbeonline.com/neisseria-gonorrhoeae-properties-disease-pathogenesis-and-laboratory-diagnosis/ ''Neisseria''] spp.
		⚫	** '''C''': ''Campylobacter'' spp.
		⚫	** '''H''': ''Helicobacter'' spp. / ''Haemophilus'' spp.
		⚫	** ''Aeromonas'' spp.

			== Further Reading ==
	The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. When present, the '''cytochrome c oxidase''' oxidizes the reagent '''(tetramethyl-p-phenylenediamine)''' to '''(indophenols)''' purple color end product. When the enzyme is not present, the reagent remains reduced and is colorless.
		⚫	* Microbe Online. [https://microbeonline.com/oxidase-test-principle-procedure-and-oxidase-positive-organisms/ Oxidase Test: Principle, Procedure and Oxidase-Positive Organisms].

	[https://i2.wp.com/microbeonline.com/wp-content/uploads/2012/12/Oxidase-test-result.gif [[File:https://i2.wp.com/microbeonline.com/wp-content/uploads/2012/12/Oxidase-test-result.gif?resize=280%2C225\|Oxidase test result]]]

	'''Note:''' All bacteria that are oxidase positive are aerobic, and can use oxygen as a terminal electron acceptor in respiration. This does NOT mean that they are strict aerobes. Bacteria that are oxidase-negative may be anaerobic, aerobic, or facultative; the oxidase negative result just means that these organisms do not have the cytochrome c oxidase that oxidizes the test reagent. They may respire using other oxidases in electron transport.

	'''Test requirements for Oxidase test:''' Moist filter paper with the substrate (1% tetramethyl-p-phenylenediamine dihydrochloride), or commercially prepared paper disk, wooden wire or platinum wire.

	== Procedure ==

	# Take a filter paper soaked with the substrate tetramethyl-p-phenylenediamine dihydrochloride
	# Moisten the paper with a sterile distilled water
	# Pick the colony to be tested with wooden or platinum loop and smear in the filter paper
	# Observe inoculated area of paper for a color change to deep blue or purple within 10-30 seconds

	=== Precautions ===

	# Do not use Nickel-base alloy wires containing chromium and iron (nichrome) to pick the colony and make smear as this may give false positive results
	# Interpret the results within 10 seconds, timing is critical
	# The oxidase test must be performed from 5% Sheep blood agar or another medium without a fermentable sugar . Fermentation of a carbohydrate results in acidification of the medium (e.g., lactose in [https://microbeonline.com/macconkey-agar-mac-composition-preparation-uses-and-colony-characteristics/ MacConkey Agar] or Sucrose in [https://microbeonline.com/thiosulfate-citrate-bile-salts-sucrose-tcbs-agarcomposition-uses-colony-characteristics/ TCBS]), and a false negative oxidase test may result if the surrounding pH is below 5.1.
	# During identification of suspected ''Vibrio cholerae'' isolate, it is not possible to perform an oxidase test directly from a '''TCBS culture''' because the acid produced by the sucrose fermenting colonies will inhibit the oxidase reaction.

	== Interpretation ==

	# '''Positive:''' Development of '''dark purple color''' (indophenols) within 10 seconds
	# '''Negative:''' Absence of color

	Bacterial genera characterized as oxidase positive include ''Neisseria'' and ''Pseudomonas''. Genera of the[https://microbeonline.com/seven-common-characteristics-family-enterobacteriaceae/ Enterobacteriaceae ]family are characterized as '''oxidase negative.'''

	'''Name of Oxidase positive bacteria are:''' '''PVNCH'''

⚫	# '''P''': ''Pseudomonas'' spp.
⚫	# '''V''': ''Vibrio cholerae''
⚫	# '''N''': [https://microbeonline.com/neisseria-gonorrhoeae-properties-disease-pathogenesis-and-laboratory-diagnosis/ ''Neisseria''] spp.
⚫	# '''C''': ''Campylobacter'' spp.
⚫	# '''H''': ''Helicobacter'' spp. / ''Haemophilus'' spp.
⚫	# ''Aeromonas'' spp.
	# Alcaligens

	[[Category:Diagnostics]]		[[Category:Diagnostics]]

Aidan at 12:18, 16 August 2019

2019-08-16T12:18:06Z

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			Source: [https://microbeonline.com/oxidase-test-principle-procedure-and-oxidase-positive-organisms/ microbonline.com]
	= Oxidase test =

	The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. When present, the '''cytochrome c oxidase''' oxidizes the reagent '''(tetramethyl-p-phenylenediamine)''' to '''(indophenols)''' purple color end product. When the enzyme is not present, the reagent remains reduced and is colorless.		The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. When present, the '''cytochrome c oxidase''' oxidizes the reagent '''(tetramethyl-p-phenylenediamine)''' to '''(indophenols)''' purple color end product. When the enzyme is not present, the reagent remains reduced and is colorless.
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	# ''Aeromonas'' spp.		# ''Aeromonas'' spp.
	# Alcaligens		# Alcaligens

			[[Category:Diagnostics]]

Aidan: Aidan moved page Oxidase to Oxidase test

2019-08-16T12:17:34Z

Aidan moved page Oxidase to Oxidase test

← Older revision		Revision as of 12:17, 16 August 2019
(No difference)

Maintenance script: Imported from text file

2019-08-11T17:58:21Z

Imported from text file

New page

= Oxidase test =

The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. When present, the '''cytochrome c oxidase''' oxidizes the reagent '''(tetramethyl-p-phenylenediamine)''' to '''(indophenols)''' purple color end product. When the enzyme is not present, the reagent remains reduced and is colorless.

[https://i2.wp.com/microbeonline.com/wp-content/uploads/2012/12/Oxidase-test-result.gif [[File:https://i2.wp.com/microbeonline.com/wp-content/uploads/2012/12/Oxidase-test-result.gif?resize=280%2C225|Oxidase test result]]]

'''Note:''' All bacteria that are oxidase positive are aerobic, and can use oxygen as a terminal electron acceptor in respiration. This does NOT mean that they are strict aerobes. Bacteria that are oxidase-negative may be anaerobic, aerobic, or facultative; the oxidase negative result just means that these organisms do not have the cytochrome c oxidase that oxidizes the test reagent. They may respire using other oxidases in electron transport.

'''Test requirements for Oxidase test:''' Moist filter paper with the substrate (1% tetramethyl-p-phenylenediamine dihydrochloride), or commercially prepared paper disk, wooden wire or platinum wire.

== Procedure ==

# Take a filter paper soaked with the substrate tetramethyl-p-phenylenediamine dihydrochloride
# Moisten the paper with a sterile distilled water
# Pick the colony to be tested with wooden or platinum loop and smear in the filter paper
# Observe inoculated area of paper for a color change to deep blue or purple within 10-30 seconds

=== Precautions ===

# Do not use Nickel-base alloy wires containing chromium and iron (nichrome) to pick the colony and make smear as this may give false positive results
# Interpret the results within 10 seconds, timing is critical
# The oxidase test must be performed from 5% Sheep blood agar or another medium without a fermentable sugar . Fermentation of a carbohydrate results in acidification of the medium (e.g., lactose in [https://microbeonline.com/macconkey-agar-mac-composition-preparation-uses-and-colony-characteristics/ MacConkey Agar] or Sucrose in [https://microbeonline.com/thiosulfate-citrate-bile-salts-sucrose-tcbs-agarcomposition-uses-colony-characteristics/ TCBS]), and a false negative oxidase test may result if the surrounding pH is below 5.1.
# During identification of suspected ''Vibrio cholerae'' isolate, it is not possible to perform an oxidase test directly from a '''TCBS culture''' because the acid produced by the sucrose fermenting colonies will inhibit the oxidase reaction.

== Interpretation ==

# '''Positive:''' Development of '''dark purple color''' (indophenols) within 10 seconds
# '''Negative:''' Absence of color

Bacterial genera characterized as oxidase positive include ''Neisseria'' and ''Pseudomonas''. Genera of the[https://microbeonline.com/seven-common-characteristics-family-enterobacteriaceae/ Enterobacteriaceae ]family are characterized as '''oxidase negative.'''

'''Name of Oxidase positive bacteria are:''' '''PVNCH'''

# '''P''': ''Pseudomonas'' spp.
# '''V''': ''Vibrio cholerae''
# '''N''': [https://microbeonline.com/neisseria-gonorrhoeae-properties-disease-pathogenesis-and-laboratory-diagnosis/ ''Neisseria''] spp.
# '''C''': ''Campylobacter'' spp.
# '''H''': ''Helicobacter'' spp. / ''Haemophilus'' spp.
# ''Aeromonas'' spp.
# Alcaligens