Evaluation of a simple method for growing Mycobacterium haemophilum

Area of Science:

• Microbiology
• Clinical Diagnostics
• Bacterial Culture

Background:

• Mycobacterium haemophilum requires specific iron-containing complexes (X factor) for growth.
• Traditional culture methods for M. haemophilum can be complex and time-consuming.
• Efficient recovery of M. haemophilum from clinical specimens is crucial for diagnosis.

Purpose of the Study:

• To evaluate the efficacy of hemin-impregnated paper strips as a simplified method for supplying the X factor.
• To determine if this simplified approach supports the growth of Mycobacterium haemophilum on standard culture media.
• To assess the utility of this method for routine clinical laboratory use.

Main Methods:

• Hemin (X factor) paper strips were placed on Middlebrook 7H10 agar and Lowenstein-Jensen media.
• One reference strain and seven clinical isolates of Mycobacterium haemophilum were tested.
• Growth was assessed around the hemin strips on both media types within two weeks.

Main Results:

• All tested strains of Mycobacterium haemophilum exhibited good growth on Middlebrook 7H10 agar supplemented with hemin strips.
• No significant growth of M. haemophilum was observed on Lowenstein-Jensen medium, even with the addition of hemin strips.
• Middlebrook 7H10 agar with hemin strips provided a reliable method for M. haemophilum recovery.

Conclusions:

• Middlebrook 7H10 agar with hemin (X factor) strips is a viable and simplified method for culturing Mycobacterium haemophilum.
• This approach eliminates the need for specialized, complex media formulations.
• The use of hemin strips on 7H10 agar represents a practical advancement for the clinical laboratory diagnosis of M. haemophilum infections.