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Table 2 Laboratory methods for identification and susceptibility testing

From: Bacterial infections in Lilongwe, Malawi: aetiology and antibiotic resistance

Organism

Media

Tests for presumptive identification

Susceptibility panel

Method

Salmonellae

BAP

Gram stain;

GNP

Disc diffusion

 

MAC

TSI;

  
  

Indole;

  
  

Colony morphology;

  
  

Urease

  

Enteric gram negative bacilli

BAP

Gram stain;

GNP

Disc diffusion

 

MAC

Colony morphology

  
  

Indole;

  
  

Oxidase;

  
  

TSI;

  
  

Citrate;

  
  

Urease

  

N. meningitidis

BAP

Gram stain

None

None

 

CHOC

Oxidase

  
 

TM

Thayer-Martin

  

S. pneumoniae

BAP

Gram stain

GPP

Disc diffusion

 

CHOC

Hemolysis Catalase

Oxacillin

 
  

Bile solubility

screening test

 

S. aureus

BAP

Gram stain

GPP

Disc diffusion

 

CHOC

Catalase

Oxacillin

 
 

MSA

Coagulase

  
  

Staphlex

  

C. neoformans

Sabouraud's

Gram stain

None

None

 

BAP

India Ink

  
  

Urease

  

Haemophilus

BAP

Gram stain

None

None

 

CHOC

Oxidase

  
  

API-NH

  

S. pyogenes

BAP

Haemolysis

GPP

Disc diffusion

  

Gram stain

  
  1. BAP = blood agar plate, MAC = MacConkey agar, CHOC = chocolate agar, TSI = triple-sugar with iron media, TM = Thayer-Martin agar, MSA = mannitol salt agar. Coagulase = tube coagulate test using human plasma; GPP = gram positive antibiotic panel, GNP = gram negative antibiotic panel, see Table 3.