What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 55665-4: Colistimethate Strip [Susc]

Name: LOINC Code 55665-4: Colistimethate Strip [Susc]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:37.765Z

55665-4 is a LOINC code used to identify Colistimethate Strip [Susc] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Colistimethate. It is commonly used with the system or sample type Isolate.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Colistimethate. It is commonly used with the system or sample type Isolate.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation
Method: Gradient strip

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Colistimethate by Gradient strip
Colistimethate
ANTIBIOTIC SUSCEPTIBILITIES; AST; Colimicina; Colimycine; Colistin sulphomethate; Colomycin M; Coly-micin S; Epsilometer; Estrip; E-strip; Grad strip; ID; Infectious Disease; InfectiousDisease; Islt; Isol; MIC; Minimum inhibitory concentration; Point in time; Random; Sus; Suscept; Susceptibilities; Susceptibility; Susceptibilty

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Colistimethate Strip [Susc]Colistimethate by Gradient stripColistimethate Islt Grad stripColistimethateABXBACTSusceptibility to ColistimethateSusc

Frequently asked questions

Code details

Code55665-4

SystemLOINC

Display nameColistimethate Strip [Susc]

DescriptionColistimethate

Short nameColistimethate Islt Grad strip

ComponentColistimethate

PropertySusc

TimingPt

System (specimen)Isolate

ScaleOrdQn

MethodGradient strip

ClassABXBACT

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.27

Last changed2.56

Consumer names

Susceptibility to Colistimethate

Part names

ColistimethateSuscPtIsolateOrdQnGradient stripSusceptibility (microorganisms)Point in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.