[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fv_4a2NrYAWclsoZckobl5ttBzkbLWVU-sGphJ5XC9F8":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":47},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":36,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":39,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"body":43,"faq":44,"tags":45,"related":46},"blood-culture-test-information-patient","Blood Culture Test: Information for the Patient",null,"Acharya Tankeshwar","2017-11-11","2025-12-29",false,"bacteriology","The target readers of this blog post are general people *(people who do not have a health science background)* who want to get basic information about “blood culture” as they or their relatives have recently been requested for blood culture or students who have just commenced their study of health science and want to have a basic understanding.\n\nTo address common queries of such people\u002Fstudents this post is written in the simplest possible way. Infectious disease specialists including physicians, microbiologists, and technologists are requested to read the technical version if they wish to have an in-depth understanding of **blood culture test.**\n\n## General Introduction\n\nBlood is a connective tissue that circulates all over the body via its channel called blood vessels. All the major organs of our body are interconnected by blood vessels. These internal organs (*e.g. kidney, liver, brain, heart, lungs*) and the blood itself is free from any living organisms (bacteria\u002F virus).\n\nOrganisms gain access to our blood vessels by various means such as brushing teeth, abrasion, trauma, surgery, etc. Such organisms now can travel via the bloodstream and reach various organs where they can initiate infection.\n\n![](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FBlood-Cells.jpg)\n\nMost of the time, our immune cells constantly patrol in blood vessels searching for any foreign invaders (organisms\u002Fpathogens), recognizing, killing, and remembering the encounter. If immune cells fail to find such invaders or kill them, these organisms will be able to colonize in some of the organs thus causing unwanted killing of our body cells or affecting our body, which generally manifests as fever, malaise, inflammation of that part, rigors depending on the types or nature of such organisms.\n\nPrescribing blood culture means your physician is requesting lab professionals (technician\u002Fmicrobiologist) to find out if your blood contains such foreign invaders. If lab people find any organism in your blood, they need to identify which organism is it and which antibiotics (if it is bacteria) will kill it. The lab will communicate this information to your physician and the physician will prescribe one or more of such antibiotics for a certain duration to make sure such organisms are killed and you will be fine.  \n\n## When Doctor requests for Blood Culture Test\n\nPhysicians may prefer blood culture in a number of suspected disease conditions which include but are not limited to;\n\n1. Enteric fever (typhoid\u002Fparatyphoid fever)\n2. Infective endocarditis *(a disease of the heart)*\n3. Meningitis *(a disease that affects brain)*\n4. Pneumonia *(a disease of the lungs)*\n5. Infection of the kidney and associated organs\n\n## Collection of the Blood for Culture\n\nAt any time, generally, such foreign invaders (organisms) are generally very less in number in blood and may not present in blood all the time *(maybe sitting in their home e.g organ where they have colonized)*. So to increase the chance of finding (isolating) such organisms, your physician may request more amount of blood (more than 5 ml depending on the age and nature of the suspected organism) or multiple samples.  \n\nOne of the biggest challenges faced during blood sample collection is making sure an organism is inadvertently introduced into the blood. As organisms are everywhere in the environment, instruments, and even our skin, the challenge is immense.\n\n![ - Collection of Blood for Culture](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FBlood-Collection-in-Bactec.jpg)\n\u003Cfigcaption>Figure: Collection of Blood for Culture\u003C\u002Ffigcaption>\n\n As the outer surface of our body contains microorganisms *(called normal flora)*, a technician should make sure,  he\u002Fshe does not contaminate the blood vial while drawing blood. For this, they use certain chemicals (iodine\u002Falcohol) to kill the normal flora around the expected area of vein puncture. They also have to make sure syringes, blood culture tubes, or bottles are free from living organisms.\n\nThey also have to make sure that the sample reaches the laboratory on time for necessary incubation (so that the organism which is in the blood, if any, won’t get killed while in transit). Some organisms are delicate, so will die, if the sample processing is delayed thus giving a false negative report i.e. you are infected with that pathogen but the *laboratory won’t be able to find out*.  \n\n## What the Lab People Do\n\nIf your blood contains microorganisms, they will utilize (eat) the nutrient available in the broth and multiply. To make sure such organisms do not die appropriate media and incubation are used. Inoculated broth is incubated in a special instrument that has a controlled environment i.e. temperature-37°*C (our body temperature)*, aeration, agitation.\n\n![ - BACTEC Blood Culture Bottle](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fbactec-culture-bottles.jpg)\n\u003Cfigcaption>Figure: BACTEC Blood Culture Bottle\u003C\u002Ffigcaption>\n\nAfter certain days, (generally 3-5 days) that instrument will give a signal about the presence of the organism. An instrument used for incubation and signaling used to rule out the presence of an organism differs according to the infrastructure available or used in your laboratory. In resource-poor settings, conventional blood culture bottles and general incubators are used but sophisticated laboratories might have access to Bactec blood culture system and some might be using an **automated blood culture system.**\n\nIf such an instrument signals the presence of an organism laboratory professionals have to sub-culture that sample in an appropriate media. Generally, [blood agar](\u002Fblood-agar-composition-preparation-uses-and-types-of-hemolysis\u002F), [chocolate agar](\u002Fchocolate-agar-composition-uses-colony-characteristics\u002F) and [MacConkey agar](\u002Fmacconkey-agar-mac-composition-preparation-uses-and-colony-characteristics\u002F) are used for this purpose. Just like we humans, organisms do have preference over nutrients i.e. some are able to utilize certain compounds but others are not. Based on this nature, organisms present in your blood preferentially grow in some or all media.\n\nWhen these organisms grow in the above-mentioned media, they may make the changes in the media where they grow. Thus, lab professionals track such changes and the appearance of such organisms to identify them. Laboratory professionals use various techniques such as Gram staining, study of morphological characteristics, or biochemical tests to identify them. Thus finally being able to recognize which organism is present in your blood sample.\n\nOrganisms that cause disease to us and are frequently isolated from blood are:\n\n1. *Salmonella Typhi\u002FParaTyphi*\n2. *Staphylococcus aureus*\n3. *Streptococcus pneumoniae*\n4. *Escherichia coli*\n5. *Acinetobacter spp*\n6. *Pseudomonas spp*\n7. *Streptococcus pyogenes*\n8. *Enterococcus spp*\n\n## Lab also tells which drug to prescribe\n\nNo single antibiotic is able to kill all organisms. So laboratory has to find out, which antibiotics may kill such bacteria.\n\n![ - Testing to find out which antibiotic will kill the organism](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FAST-Plate.png)\n\u003Cfigcaption>Figure: Testing to find out which antibiotic will kill the organism\u003C\u002Ffigcaption>\n\nAs organisms are evolving and acquiring resistance *(called drug resistance or antibiotics resistance which is a major global issue)* laboratory has to find out which antibiotic will kills that particular isolate.\n\nFor this, they test that organism against a panel of antibiotics based on the nature of the organism and find out which antibiotics actually kill that organism. After the completion of the processing, the laboratory gives a report mentioning which organism is isolated (if any) and which antibiotics will kill that organism. Your physician chooses among these antibiotics and prescribes you the medication.\n\n**After how many days I will get a report of Blood Culture Test?**\n\nGenerally, it takes 3-7 days to get your blood culture report. If the suspicion is the involvement of a slow-growing organism sometimes it may take weeks to rule out the presence of the organism in your blood.  \n\n**References**\n\n1. Washington J. A., 2nd (1975). Blood cultures: principles and techniques. *Mayo Clinic proceedings*, *50*(2), 91–98.\n2. Aronson, M. D., & Bor, D. H. (1987). Blood cultures. *Annals of internal medicine*, *106*(2), 246–253. [https:\u002F\u002Fdoi.org\u002F10.7326\u002F0003-4819-106-2-246](https:\u002F\u002Fdoi.org\u002F10.7326\u002F0003-4819-106-2-246)",[],[],[],[48,54,61,66,70,74,79,84,88,92],{"slug":49,"name":38,"description":50,"image":51,"body":52,"postCount":53},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":55,"name":56,"description":57,"image":58,"body":59,"postCount":60},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":62,"name":63,"description":64,"image":37,"body":37,"postCount":65},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":67,"name":68,"description":64,"image":37,"body":37,"postCount":69},"samikshya-acharya","Samikshya Acharya",20,{"slug":71,"name":72,"description":64,"image":37,"body":37,"postCount":73},"alisha-tripathi","Alisha Tripathi",6,{"slug":75,"name":76,"description":77,"image":37,"body":37,"postCount":78},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",9,{"slug":80,"name":81,"description":82,"image":37,"body":37,"postCount":83},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":85,"name":86,"description":64,"image":37,"body":37,"postCount":87},"srijana-khanal","Srijana Khanal",18,{"slug":89,"name":90,"description":82,"image":37,"body":37,"postCount":91},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":93,"name":94,"description":64,"image":37,"body":95,"postCount":96},"nisha-rijal","Nisha Rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]