All Notes

Hemolysis and Hemodigestion: Introduction, Differences, and Related Footages

Introduction of Hemolysis and Hemodigestion

When the pure isolated colony of organism on a blood agar plate is exposed in bright transmitted light, we differentiate between hemolysis and hemodigestion since hemolysis is the process of killing blood cells by bacteria, and the area surrounding a single colony becomes partial clear (alpha hemolysis e.g. Streptococcus pneumoniae ) or completely clear (beta hemolysis e.g. Streptococcus agalactiae) whereas in hemodigestion no clear zone can be seen near single colony but can be observed near the dense streaked area of the bacteria (Vibrio cholerae).

Hemolysis (left)-Beta-hemolysis of S. aureus on blood agar in bright transmitted light and Hemodigestion (right)- Vibrio cholerae on blood agar

Difference between Hemolysis and Hemodigestion

The differences between hemolysis and hemodigestion are summarized as follows-

HemolysisHemodigestion
A clear zone surrounding a single colony A clear zone near the dense streaked area
A clear zone with debrisA clear zone without debris
Bacteria use hemolysins that cause lysis of blood cells.It is the nonspecific killing of blood cells by metabolic by-products of bacteria.
Microbes responsible for hemolysis mainly express partial and complete hemolysis. e.g. Streptococcus pneumoniae (partial hemolysis) and Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalactiae (clear zone)Microbes responsible for hemodigestion mainly express the greenish zone that appears around the colonies and later becomes clear. e.g. Vibrio cholerae
Table: Differences between hemolysis and haemodigestion

Alpha hemolysis of Streptococcus pneumoniae

Fig. Alpha hemolysis of Streptococcus pneumoniae

Beta-hemolysis of Staphylococcus aureus

Fig. Beta-hemolysis of Staphylococcus aureus

Streptococcus pyogenes beta-hemolytic colony

Fig. Streptococcus pyogenes beta-hemolytic colony

Streptococcus agalactiae beta-hemolytic colony on blood agar of high vaginal swab culture

Fig. Streptococcus agalactiae beta-hemolytic colony on blood agar of high vaginal swab culture

The greenish colonies of Vibrio cholerae on blood agar

Fig. The greenish colonies of Vibrio cholerae on blood agar later become clear as shown below image.

Hemodigestion on blood agar by Vibrio cholerae

Fig. Hemodigestion on blood agar by Vibrio cholerae

Hemodigestion on blood agar by bacteria

Fig. Hemodigestion on blood agar by bacteria

Further Reading

  1. researchgate.net/post/Difference_between_Hemolysis_and_Hemodigestion
  2. https://universe84a.com/collection/blood-agar-haemodigestion/
  3. awetz, Melnick and Adelberg’s Medical Microbiology. Editors: Geo. F. Brook, Janet S. Butel & Stephen A. Morse, 21st ed 1998, Publisher Appleton & Lance, Co Stamford Connecticut.
  4. Mackie and Mc Cartney Practical Medical Microbiology. Editors: J.G. Colle, A.G. Fraser, B.P. Marmion, A. Simmous, 4th ed, Publisher Churchill Living Stone, New York, Melborne, Sans Franscisco 1996.
  5. Manual of Clinical Microbiology. Editors: P.R. Murray, E. J. Baron, M. A. Pfaller, F. C. Tenover and R. H. Yolken, 7th ed 2005, Publisher ASM, USA
  6. District Laboratory Practice in  Tropical Countries  –  Part-2-   Monica Cheesebrough-   2nd Edn Update
  7. Text book of Diagnostic Microbiology. Editors: Connie R. Mahon, Donald G. Lehman & George Manuselis, 3rd edition2007, Publisher Elsevier.
  8. https://www.jfmed.uniba.sk/fileadmin/jlf/Pracoviska/ustav-mikrobiologie-a-imunologie/VLa/STREPTOCOCCI.pdf
Medical Lab Notes

View Comments

  • Thank you for all of the effort on this web page. My mom really likes doing internet research and it is obvious why. I know all relating to the dynamic medium you make important tips by means of this blog and as well attract contribution from visitors on that concept so our favorite child is truly being taught a great deal. Enjoy the rest of the year. Your performing a glorious job.

  • This is a very good tips especially to those new to blogosphere, brief and accurate information… Thanks for sharing this one. A must read article.

  • We're a group of volunteers and starting a new scheme in our community. Your web site provided us with valuable info to work on. You've done an impressive job and our whole community will be grateful to you.

  • Regards for this wondrous post, I am glad I found this website on yahoo.

  • I am typically to running a blog and i actually admire your content. The article has really peaks my interest. I'm going to bookmark your web site and preserve checking for brand new information.

  • Hello there, simply turned into alert to your weblog thru Google, and found that it's really informative. I am gonna watch out for brussels. I will appreciate if you happen to proceed this in future. A lot of people will likely be benefited from your writing. Cheers!

  • Great blog here! Also your site loads up fast! What host are you using? Can I get your affiliate link to your host? I wish my site loaded up as fast as yours lol

  • Hey very nice site!! Man .. Excellent .. Amazing .. I will bookmark your blog and take the feeds also…I'm happy to find a lot of useful information here in the post, we need work out more strategies in this regard, thanks for sharing. . . . . .

  • Write more, thats all I have to say. Literally, it seems as though you relied on the video to make your point. You clearly know what youre talking about, why waste your intelligence on just posting videos to your weblog when you could be giving us something informative to read?

  • Somebody essentially help to make seriously articles I would state. This is the first time I frequented your web page and thus far? I amazed with the research you made to make this particular publish amazing. Excellent job!

Recent Posts

Acinetobacter haemolyticus-Introduction, Morphology, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes

Introduction Acinetobacter haemolyticus is an aerobic, non-fermenting bacterium found in nature and hospital environments. It belongs…

2 days ago

Nakaseomyces glabratus: Introduction, Morphology, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes

Introduction Nakaseomyces glabratus (formerly Candida glabrata) is a highly adaptable, haploid yeast that is a common commensal…

1 week ago

Pichia kudriavzevii-Introduction, Morphology, Pathogenicity, Lab Diagnosis, Treatment, Prevention, and Keynotes

Introduction Pichia kudriavzevii, formerly known as Candida krusei, is a unique budding yeast that holds a…

1 week ago

Morphological Characterization of MTBC: Identifying “Buff” Granular Growth in MGIT Liquid Culture

Visual Observation Medium: The tubes appear to be MGIT (Mycobacteriological Growth Indicator Tubes), which contain…

1 week ago

Transforming Infectious Disease Diagnostics with tNGS Technology

In the world of modern diagnostics, speed, accuracy, and comprehensiveness are critical—especially when dealing with…

2 weeks ago

Revolutionizing Molecular Diagnostics: A Look Inside Bioeksen’s Innovative Solutions

Introduction In today’s rapidly evolving healthcare landscape, the demand for fast, accurate, and accessible diagnostic…

2 weeks ago