thanks so much Mr. Tracy, I'm a CLT student and I'm doing my clinical rotation for microbiology section at the lab. These videos clarify what/how/why of urine cultures!
I'm no medical student, but I'm definitely experienced in having utis! It's very interesting to see what you guys do with our urine cultures and how you identify the specimen. Looking at how contamination works, I'm very motivated to make the midstream catch more sterile with my new understanding of this process.
It is very difficult, if not impossible, to get a midstream specimen that has absolutely no contamination, but to increase your chances of getting one that has as little contamination as possible, you should do a couple things. First, if you know you are going to be giving a urine sample, you should be clean. That means bathing or showering and making sure your genital area is clean. Second, follow the instructions that you receive for collecting a midstream urine sample. Your nurse or medical assistant should give you this information, or sometimes instructions are posted in the bathroom where you are to collect the specimen.
Thank you Mr . Tracy you video is so helpful since it my first day in microbiology lab and it is the first time seeing a real pathogen organism growing not like at college with normal specimen
thank you very much.. but if i was doing culture for sort throat and the bacteria was among normal flora, what should i write in my repoer and should i do sensitivity test for it?
In practice I have seen gram neg (most commonly proteus mirablis but also e. coli and k. pneumo) grow on CNA. But realizing that what you see on the TSA is also what you see on Mac can be challenging to learn. Many times when I was learning, and most of the interns I have dealt with tend to treat them as separate and want to work everything up. I have found that bacteria love to try to fool us anyway they can.
It's difficult to make clear-and-fast rules in microbiology. The goal of these videos is to deliver general rules rather than exceptions. If I went down that rabbit hole, they would each be an hour long. Thanks for your comments.
@@priyak6945 It is not possible to say that all colonies of non-pathogenic Neisseria spp. look a certain way. N. sicca has a breadcrumb-like colony, but N. lactamica looks like N. meningitidis.
Nice video. If you had about 20 alpha gram positive cocci colonies that were pyr negative and also 10 coag neg staph colonies, how would this be worked up? The urinalysis results are normal.
It would depend on the type of collection. If it was a clean-catch, I probably wouldn't do much with it except give the numbers and what I think the organisms may be. In situations like this, plates are usually held in case the physician wants to work it up. Maybe something like "10-20,000 alpha-hemolytic strep, 10,000 coag-negative staph. Plates held for 7 days." If it was an indwelling catheter or suprapubic aspirate, then I would probably work everything up. It all depends on the facility's standard operating procedure (SOP).
Sir in blood agar sensitivity for streptococcus how will u read sensitive and resistant pattern i mean no grth around antibiotics is resistant please say sir
An antibiotic disc placed on a blood agar plate will have a certain concentration of the antibiotic in it as determined by the manufacturer. Based on the manufacturer's guidelines, usually a measured zone of no growth around the disc is how we measure whether an organism is sensitive or resistant. For example, if you make a lawn of Streptococcus pneumoniae on a blood agar plate and put an optochin disc in the center of it, a zone of 18 mm of no growth around the disc may be considered sensitive thus positive for Streptococcus pneumoniae.
I made a mistake instead of streptococcus I was checking staphylococcus saprophyticus I put novobiocin I inoculate organism and placed nv novobiocin for nv originally bacteria shows resistant so it means it is s saprophyticus I cannot find any grth around the disc not only around the disc in the inoculated area it shows resistant to that antibiotics so my doubt is that bacteria is staphylococcus saprophyticus or any mistakes
I have a question Patrick Tracey why you are not gonna go with it if it's clean catch specimen and work that one which in this case may be a catheter specimen as u said in the 7th sample , is it due to contamination will be present if it's a clean catch specimen right? please need answer
Hi Dario,Clean-catch specimens are frequently contaminated. For the collection of a catheterized specimen, basically a tube is inserted into the urethra and therefore there is a much lower chance of the specimen being contaminated. Any growth on the plates of a catheterized specimen are therefore considered more significant than those from a clean-catch specimen. For example, 5-10,000 CFU/ml on a clean-catch culture may not be worked up and may just get a report like "5-10,000 CFU/ml of probable E. coli. Plates held for 5 days". On a catheterized culture, this may be worked up and a receive a preliminary report of "5-10,000 CFU/ml of probable E. coli. Identification and sensitivity testing to follow". Then of course the final result would be sent out after ID and sensitivity testing have been completed.
Ok but clean-catch specimen is also may not be contaminated what if there are significance amount of colonies for a clean catch then what would we further go for it if the amount of colonies exceeds how to say >30000 or >100000 it should be considered for the preliminary report should be a concern right which indicates an infection.
@@patricktracy9947 I have enormous interest in Microbiology i have downloaded all of your videos and liked it and studying it for my knowledge and you are a very knowledgeable Instructor :) please if you use gmail or any other account you have i have many questions regarding these cultures so i contact you looking forward for your replies to my question and ur contact Email Address Thank you
How urine cultures are worked up depends on the microbiology laboratory's standard operating procedures (SOPs). More than likely the urine culture SOP will have thresholds. For example, a clean-catch specimen with 10-20,000 CFU/ml of one colony type may get a tentative identification like "10-20,000 CFU/ml probable Enterococcus. Plate held for 5 days". But if there are 20-30,000 CFU/ml then it may get worked up, and the preliminary report would be "20-30,000 CFU/ml probable Enterococcus. Identification and sensitivity testing to follow". So the threshold is 20,000 CFU/ml. Catheterized specimens tend to have lower thresholds.
Yes, Candida can be a stool pathogen although it is rare. Candida is an opportunistic pathogen so if normal stool flora is disrupted, Candida may have a chance to gain control of the bowel flora.
@@priyak6945 We can't really identify an organism without specific biochemical or molecular testing. We can, however, give the doctor a preliminary report. For example, if I read a urine culture after 24 hours of incubation and saw 50,000 CFUs/ml of an oxidase-negative colony that is lactose-positive and has a fried-egg apperance on MacConkey agar, I can report "50,000 CFUs/ml of probable E. coli. Identification and susceptibilty results to follow"
@@priyak6945 With experience you can suggest what the identification of an organism is, but the identification needs to be confirmed with molecular or biochemical testing.
thanks so much Mr. Tracy, I'm a CLT student and I'm doing my clinical rotation for microbiology section at the lab. These videos clarify what/how/why of urine cultures!
Hi Michell, I am glad they were helpful for you.
I'm no medical student, but I'm definitely experienced in having utis! It's very interesting to see what you guys do with our urine cultures and how you identify the specimen. Looking at how contamination works, I'm very motivated to make the midstream catch more sterile with my new understanding of this process.
It is very difficult, if not impossible, to get a midstream specimen that has absolutely no contamination, but to increase your chances of getting one that has as little contamination as possible, you should do a couple things. First, if you know you are going to be giving a urine sample, you should be clean. That means bathing or showering and making sure your genital area is clean. Second, follow the instructions that you receive for collecting a midstream urine sample. Your nurse or medical assistant should give you this information, or sometimes instructions are posted in the bathroom where you are to collect the specimen.
Thank you Mr . Tracy you video is so helpful since it my first day in microbiology lab and it is the first time seeing a real pathogen organism growing not like at college with normal specimen
Thank you HAYA...I am glad the videos are helpful.
Sir How we can identify citrobacter just preliminary identification on macconkey and blood agar
thank you very much..
but if i was doing culture for sort throat and the bacteria was among normal flora, what should i write in my repoer and should i do sensitivity test for it?
In practice I have seen gram neg (most commonly proteus mirablis but also e. coli and k. pneumo) grow on CNA. But realizing that what you see on the TSA is also what you see on Mac can be challenging to learn. Many times when I was learning, and most of the interns I have dealt with tend to treat them as separate and want to work everything up. I have found that bacteria love to try to fool us anyway they can.
It's difficult to make clear-and-fast rules in microbiology. The goal of these videos is to deliver general rules rather than exceptions. If I went down that rabbit hole, they would each be an hour long. Thanks for your comments.
Thank a lot for helping me thru this video
My pleasure :)
Sir will u put more videos discussion like cervical swab culture, aspirate etc it will be help me a lot
Sir what is the colony morphology of non pathogenic Neisseria (is it nmnlf non mucoid nlf)
@@priyak6945 It is not possible to say that all colonies of non-pathogenic Neisseria spp. look a certain way. N. sicca has a breadcrumb-like colony, but N. lactamica looks like N. meningitidis.
Can we say beta hemolytic grey colony on blood agar as gram negative bacilli as a preliminary report I think one my tutor descrbe like this
Sir for an 8 months old child shows cephems resistant .is it any mistake in sensitivity reading
Sir what happened to you no reply
That's amazing video
Nice video. If you had about 20 alpha gram positive cocci colonies that were pyr negative and also 10 coag neg staph colonies, how would this be worked up? The urinalysis results are normal.
It would depend on the type of collection. If it was a clean-catch, I probably wouldn't do much with it except give the numbers and what I think the organisms may be. In situations like this, plates are usually held in case the physician wants to work it up. Maybe something like "10-20,000 alpha-hemolytic strep, 10,000 coag-negative staph. Plates held for 7 days." If it was an indwelling catheter or suprapubic aspirate, then I would probably work everything up. It all depends on the facility's standard operating procedure (SOP).
Mixed orgs present, insignificant colony count. Request new clean catch specimen.
Sir how will process tracheal aspirate by direct plating or 1:10and1:100 dilution method will you explain it
Hi Priyak, I don't have experience with diluting tracheal aspirates.
Then direct plating tracheal aspirate on media that is my doubt (about processing)
Sir in blood agar sensitivity for streptococcus how will u read sensitive and resistant pattern i mean no grth around antibiotics is resistant please say sir
An antibiotic disc placed on a blood agar plate will have a certain concentration of the antibiotic in it as determined by the manufacturer. Based on the manufacturer's guidelines, usually a measured zone of no growth around the disc is how we measure whether an organism is sensitive or resistant. For example, if you make a lawn of Streptococcus pneumoniae on a blood agar plate and put an optochin disc in the center of it, a zone of 18 mm of no growth around the disc may be considered sensitive thus positive for Streptococcus pneumoniae.
I made a mistake instead of streptococcus I was checking staphylococcus saprophyticus I put novobiocin I inoculate organism and placed nv novobiocin for nv originally bacteria shows resistant so it means it is s saprophyticus I cannot find any grth around the disc not only around the disc in the inoculated area it shows resistant to that antibiotics so my doubt is that bacteria is staphylococcus saprophyticus or any mistakes
I have a question Patrick Tracey why you are not gonna go with it if it's clean catch specimen and work that one which in this case may be a catheter specimen as u said in the 7th sample , is it due to contamination will be present if it's a clean catch specimen right? please need answer
Hi Dario,Clean-catch specimens are frequently contaminated. For the collection of a catheterized specimen, basically a tube is inserted into the urethra and therefore there is a much lower chance of the specimen being contaminated. Any growth on the plates of a catheterized specimen are therefore considered more significant than those from a clean-catch specimen. For example, 5-10,000 CFU/ml on a clean-catch culture may not be worked up and may just get a report like "5-10,000 CFU/ml of probable E. coli. Plates held for 5 days". On a catheterized culture, this may be worked up and a receive a preliminary report of "5-10,000 CFU/ml of probable E. coli. Identification and sensitivity testing to follow". Then of course the final result would be sent out after ID and sensitivity testing have been completed.
Ok but clean-catch specimen is also may not be contaminated what if there are significance amount of colonies for a clean catch then what would we further go for it if the amount of colonies exceeds how to say >30000 or >100000 it should be considered for the preliminary report should be a concern right which indicates an infection.
@@patricktracy9947 I have enormous interest in Microbiology i have downloaded all of your videos and liked it and studying it for my knowledge and you are a very knowledgeable Instructor :) please if you use gmail or any other account you have i have many questions regarding these cultures so i contact you looking forward for your replies to my question and ur contact Email Address
Thank you
I can be contacted at ptracy@wvc.edu
How urine cultures are worked up depends on the microbiology laboratory's standard operating procedures (SOPs). More than likely the urine culture SOP will have thresholds. For example, a clean-catch specimen with 10-20,000 CFU/ml of one colony type may get a tentative identification like "10-20,000 CFU/ml probable Enterococcus. Plate held for 5 days". But if there are 20-30,000 CFU/ml then it may get worked up, and the preliminary report would be "20-30,000 CFU/ml probable Enterococcus. Identification and sensitivity testing to follow". So the threshold is 20,000 CFU/ml. Catheterized specimens tend to have lower thresholds.
Sir is candida sp pathogens in stool culture
Yes, Candida can be a stool pathogen although it is rare. Candida is an opportunistic pathogen so if normal stool flora is disrupted, Candida may have a chance to gain control of the bowel flora.
Without biochemical test how will u sir u will identify particular organism from colony morphology will u explain it sir
Please
@@priyak6945 We can't really identify an organism without specific biochemical or molecular testing. We can, however, give the doctor a preliminary report. For example, if I read a urine culture after 24 hours of incubation and saw 50,000 CFUs/ml of an oxidase-negative colony that is lactose-positive and has a fried-egg apperance on MacConkey agar, I can report "50,000 CFUs/ml of probable E. coli. Identification and susceptibilty results to follow"
Can by experience
@@priyak6945 With experience you can suggest what the identification of an organism is, but the identification needs to be confirmed with molecular or biochemical testing.
A moderate grth of Candida a pathogen in pus or consider it as a normal skin flora
I can't answer that question. You have given me too little information.
Very helpful Sir... Thank you
I am glad it helped you.
the ECHA is the leading organism in this case . I would test it and the others I would give as mixed flora.
Probably, but it does contain mixed flora.
@@patricktracy9947 that is what I am saying. Are You a Medical Laboratories Technologist too? Love you videos!
I am the director of an MLT program, but I am actually a Medical Technologist (Medical Laboratory Scientist). Glad the videos are helpful.