Microbiology Quick Reference - Revision history

Admin: /* Enterococcus sp. */

2025-02-25T16:47:08Z

Enterococcus sp.

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+|
 |}
 Chromogenic Agars
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 * Brilliance GBS agar
 == Specimen Collection ==

Admin: /* Organism Testing */

2025-02-25T04:08:04Z

Organism Testing

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 * PVA polyvinyl alcohol (PCR and staining)
 * SAF sodium acetate-acetic acid-formalin (concentration and staining)
 GBS Screen
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 |Catalase
 |''Staphylococcus spp.''
+|''Streptococcus spp.''
+|
 |-
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 |-
 |PYR
+|
+|
 |}
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+|
 |}
 Organisms of infection control concern
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 ''E. casseliflavus''
-Catalase
+==== Enterobacterales ====
-Oxidase
+Yersinia
-PYR
+* NLF
 == Antibiotic Susceptibility Testing ==

Admin: /* Streptococcus species */

2025-02-25T03:28:50Z

Streptococcus species

Show changes

Admin: /* Specimen Collection */

2025-02-25T00:50:01Z

Specimen Collection

← Older revision		Revision as of 20:50, 24 February 2025
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	\|}		\|}

			== Organism Testing ==
	{\| class="wikitable"		{\| class="wikitable"
	\|+		\|+
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	* GPC clusters		* GPC clusters
	* Catalase +		* Catalase +
	* Coagulase +		* Coagulase + (forms clot in plasma due to Staphylocoagulase)
	* Staphaureux +		* Staphaureux +

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	* ''S. lugdunensis'': PYR +		* ''S. lugdunensis'': PYR +
			** Has clumping factor that '''can cause weak false positives'''!
	* ''S. saprophyticus'' (females 12-60): Novobiocin resistant		* ''S. saprophyticus'' (females 12-60): Novobiocin resistant
	* Others: ''S. epidermidis'', other CoNS		* Others: ''S. epidermidis'', ''S. hominis'', other CoNS
			Related Species (''Micrococcus, Stomatococcus, Planococcus'')

			* Often normal flora
			* Similar test results to ''Staphylococcus'' spp.

	==== ''Streptococcus'' species ====		==== ''Streptococcus'' species ====
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	PYR		PYR

	~~Mycology~~		== Antibiotic Susceptibility Testing ==
			MRSA

			* Penicillins bind to PBP (penicillin binding protein) = inhibits cell wall formation
			* MRSAs have mecA gene encoding PBP2a
			** PBP2a resistant to ALL beta-lactams

			BORSA (Borderline Oxacillin Resistant ''Staphylococcus aureus'')

			* '''NOT''' due to mecA (therefore, have altered PBP but '''NOT''' PBP2a)
			* Due to superproduction of beta-lactamase
			* MIC above oxacillin breakpoints (>4 μg/mL), but don't grow on oxacillin screen plates

			VISA

			* Vancomycin MIC breakpoint 4-8 μg/mL
			* Possibly due to thickened cell wall, trapping antibiotic

			VRSA

			* Vancomycin MIC breakpoint >8 μg/mL
			* vanA resistance from plasmids or transposons (e.g., from VREs)

			== Mycology ==
	* Malassezia furfur = Tinea versicolour = budding yeast and hyphae in 10% KOH ("spaghetti and meatballs")		* Malassezia furfur = Tinea versicolour = budding yeast and hyphae in 10% KOH ("spaghetti and meatballs")
	* Candida albicans = polymorphic, chlamydospore +, germ tube +, urea -		* Candida albicans = polymorphic, chlamydospore +, germ tube +, urea -
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	* Cryptococcus = germ tube -, india ink +, urea +		* Cryptococcus = germ tube -, india ink +, urea +

	Parasitology		== Parasitology ==

	* Definitive/true host = where parasite develops into sexually mature (adult) form		* Definitive/true host = where parasite develops into sexually mature (adult) form
	* Intermediate/secondary host = in-between host where parasite is sexually immature (e.g., larvae)		* Intermediate/secondary host = in-between host where parasite is sexually immature (e.g., larvae)

Admin: /* Streptococcus species */

2025-02-22T05:36:35Z

Streptococcus species

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+|
 |}
 == Stains ==
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 PYR
 == Polymerase Chain Reaction ==

Admin at 20:33, 20 February 2025

2025-02-20T20:33:44Z

Show changes

Admin at 19:16, 20 February 2025

2025-02-20T19:16:44Z

Show changes

Admin: Created page with "{| class="wikitable" |+ !Test !Positive QC !Negative QC !Uses |- |Catalase |''Staphylococcus spp.'' | | |- |Coagulase | rowspan="2" |''S. aureus'' | rowspan="2" |Other ''Staphylococcus'' | |- |Staphaureux (Latex agglutination) | |- |PYR |''S. lugdunensis'' | | |} ==== ''Staphylococcus'' species ==== ''Staphylococcus aureus'' * GPC clusters * Catalase + * Coagulase + * Staphaureux + If coagulase/Staphaureux negative, then CoNS: * ''S. lugdunensis'': PYR + * ''S. sapro..."

2025-02-14T15:58:10Z

Created page with "{| class="wikitable" |+ !Test !Positive QC !Negative QC !Uses |- |Catalase |''Staphylococcus spp.'' | | |- |Coagulase | rowspan="2" |''S. aureus'' | rowspan="2" |Other ''Staphylococcus'' | |- |Staphaureux (Latex agglutination) | |- |PYR |''S. lugdunensis'' | | |} ==== ''Staphylococcus'' species ==== ''Staphylococcus aureus'' * GPC clusters * Catalase + * Coagulase + * Staphaureux + If coagulase/Staphaureux negative, then CoNS: * ''S. lugdunensis'': PYR + * ''S. sapro..."

New page

{| class="wikitable"
|+
!Test
!Positive QC
!Negative QC
!Uses
|-
|Catalase
|''Staphylococcus spp.''
|
|
|-
|Coagulase
| rowspan="2" |''S. aureus''
| rowspan="2" |Other ''Staphylococcus''
|
|-
|Staphaureux (Latex agglutination)
|
|-
|PYR
|''S. lugdunensis''
|
|
|}

==== ''Staphylococcus'' species ====
''Staphylococcus aureus''

* GPC clusters
* Catalase +
* Coagulase +
* Staphaureux +

If coagulase/Staphaureux negative, then CoNS:

* ''S. lugdunensis'': PYR +
* ''S. saprophyticus'' (females 12-60): Novobiocin resistant
* Others: ''S. epidermidis'', other CoNS

==== ''Streptococcus'' species ====

* GPC pairs & chains
* Catalase -

Lancefield grouping mainly used for ID
{| class="wikitable"
|+
!Lancefield Grouping
!Organism
!Features
!Clinical Relevance
|-
|Group A
|''S. pyogenes''
|
* Beta-heme
* PYR +
|iGAS
|-
|Group B
|''S. agalactiae''
|
* Beta-heme
|
|-
| rowspan="2" |Group D
|''S. bovis''
|
|
|-
|Enterococcus

|
|
|-
|Group C
| rowspan="2" |''Streptococcus dysgalactiae'' subsp ''equisimilis''
| rowspan="2" |Beta-heme
| rowspan="2" |Normally commensal
|-
|Group G
|-
|
|''S. pneumoniae''
|
* Alpha-heme
* Bile soluble
* Optochin sensitive (≥14mm)
|
|-
|
|Viridans Streptococci
|
|
|}
Catalase

Oxidase

PYR