Agnieszka Mrozinska
Hello! I am a Biomedical Sciences student with a passionate interest in Microbiology! I am also interested in genetics and... History and cooking!
Location Reading, United Kingdom
Activity
-
Agnieszka Mrozinska made a comment
The gut microbiome in recent years have been shown to play a significant role in the organisms health and disease states. The dysbiosis, alternations to natural microbiome, have been correlated with diseases affecting central nervous system including autism, Parkinson's and depression. As the gut microbiome health is believed to be important mediator of whole...
-
Hi Marie!
Thank you for an insightful response! Hope you are enjoying the course so far! -
Dear Angelina! Welcome to the course and I do hope you will enjoy it as much as I do! We do have some practical experiments you can perform at home and share your results; furthermore, videos of practical experiments performed in a laboratory environment are available for you to view and study during the course. I do hope you will find them interesting and...
-
Hello Natalie! You have raised an important aspect here- microbes are very important both as skin and gut microbiomes. One of many important roles played by resident microorganisms is the nutrient restriction, preventing harmful microbiota growth both on the skin surface and within our digestive system. I like to think of our skin microbiota as an invisible...
-
A very good point- anti-vaccination protests are quite concerning. However, sadly, they are not restricted to the Coronavirus vaccine. In the last two decades deaths (in some countries, such as USA) from Measles has been much higher than in 20th century, an increase which correlates highly with a decrease in the vaccine uptake.
The anti-vaccination...
-
Hi Eduardo! Yes, You are right- it is extremely important to ensure completion of the antibiotic course. It is also correct that new antibiotic agent production is not profitable for pharmaceutical companies- when a new antibiotic come to market, it likely would be shelved and use only when nothing else works, in order to prevent new resistance emergence....
-
Agnieszka Mrozinska replied to ABDUL ZERIA
Welcome to the course Abdul!
-
Welcome Katherine! Hope you will enjoy the course!
-
Welcome Sonia!
-
Hi Louise! Those are not pleasant at all! However they are just a tiny fraction of a huge array of fungi kindom!
-
Dear Judith!
In those times, they did not believe in disease-causing microorganisms, but in the imbalance of humors: fire, water, earth and air. Illness was often attributed to patient's having too much blood- hence bleeding. Considering they had no antiseptics that time, if was a sure way to introduce even more infectious agents; however, I would like think... -
Dear John!
Very interesting point. The RNA World theory supports notion that simple RNA viruses (not encapsulated) were the very first 'alive' entity; thanks to RNA intrinsic ability to multiply on its own. During the proposed time period when the 'RNA World' existed, the Earth was very much inhospitable as some other planets are now- hot and anoxic.... -
Hello John! Welcome to the course!
-
Hello Melanie! Welcome to the course- please let us know if you have any questions on the way!
-
Hello Amelia! Welcome to the course- hope you will enjoy it. Oral microbiota is very important, and it can also go very wrong; hence the need of good oral hygine!
-
In this case we are looking at soil resident microbes, therefore bacteria able to grow over a range of different temperatures; therefore the exact incubation temperature is not specific . In this case, the ambient temperature would be room temperature (20-22), however 37 degree can also be used.
-
Hi Sareer! Good question! Let's have a look at the video, there are some clues as to why gloves are not required.
Firstly, Harriet is working next to an open flame, which if rightly used should protect her work from contamination. We must be very careful when working is such close proximity to flame- serious burns can occur! In this instance, wearing gloves... -
Dear Gillian! Extremophiles were actually the first colonisers of our planet 3.5bln years ago. They are being studied to understand limits of life, as well as changes that taken place in Earth atmosphere since then.
-
Agnieszka Mrozinska replied to Gillian Shannon
Dear Gillian! Yes, microbes compete for the adhesion sites and nutrients available, which means strain better adapted to persist, uptake and utilise nutrients will outgrow others. This is how commensal bacteria prevents growth of pathogenic strains. However, it is important to note that the stopping growth does not mean clearance- even if strains are unable to...
-
Hi! It should be working well now!
-
Hello! I have highlighted the issue to the course creators and it seems the issue is now fixed- please let me know if there are any other issues please! Enjoy
-
Dear Khalid! Thank you for the information, I will pass it along.
-
Hello Osanda! Welcome to the course! We will be happy to answer any questions you may have, and join any discussions you find interesting. Hope you will enjoy the course!
-
Welcome Doris! Hope you will find this course engaging and interesting! If you have any questions, we are here to help!
-
Agnieszka Mrozinska replied to Ros C
Dear Ros! That's correct! This is why some food taste sour and some people more than other dislike food like Brussel sprouts or other sour tasting foods. As humans, in the process of natural selection we have learnt that sour food mean spoilt or even poisonous. therefore, our early ancestors, when hunting and gathering, learned to avoid such flavours....
-
Dear Isobel! I must agree it would be very tempting to ask for every child to be vaccinated; however, it would be very hard indeed. Unfortunately, years ago, a scientific paper has been published which draw connections between early vaccinations and autism. What resulted were mass protests against vaccines, especially MMR (mumps, measles and rubella) which...
-
Agnieszka Mrozinska made a comment
AT the moment prophylactic use of antibiotics in animal farming is forbidden in the EU; however, it is still a common place in other countries such as USA. Furthermore, antibiotic use is allowed to treat diseased animals- if a milk cow has an infection that requires treatment, her milk will be poured down the drain for the time of treatment and beyond. This...
-
I have been listening to a science podcast recently, where a mathematical calculated how long it would take for a waste matter to reach our armpits- if there would be no fungi to degrade it. They have estimated that without microbes and fungi to degrade it, it would take only 3 years for the waste to reach 1.2 m in hight. Incredible!
-
Dear Michael!
Each colony forming unit has been derived from a single bacterium- depending on incubation conditions, time of incubation and quality of media, as well as motility ability of bacteria, number of bacterial cells in colony will differ.
Cell counts can be estimated by mannual counting of bacterial cells in a carefully measured sample, under... -
Agnieszka Mrozinska replied to Blanchard Bancouli
Dear Blanchard! The microorganisms are not actually in our body- the digestive tract is technically on the 'outside'; when they start invading there is start of infection. The bacterial growth on our skin, and in the intestines is controlled by the space available to attach and growth, and availability and quality of nutrients. Someone eating diet rich in meat...
-
Yes! It was this very programme that send me on to study Biomedical Sciences at the University of Reading. Truly inspiring!
-
Dear Renata, I am sorry to hear that. If you could let me know what device and which search engine have you used, I could forward this information to the course creators, so it can be acted upon and improved.
-
Agnieszka Mrozinska replied to Gertruda Klimek
Dear Gertruda! Mutations are simply a mistake in copying the 4-letter code; which is actually performed by a host's cell. The reason why mutations are much more noticeable in viruses produced by human cells than in human cells themselves, is because:
a) 100-1000s of viral particles is being produced per cell (as opposed to 1 cell giving rise to 2 daughter... -
Agnieszka Mrozinska replied to Carola Z
Dear Carola! It is not exactly leftover genomic material floating around that makes viruses; when it comes to bacteriophages, the viruses infecting bacteria, they have a tightly controlled number of nucleotides that can fit into the viral particle, the core. Although mutations do happen, most often they take place during viral replication within the host cell....
-
Hi Natalie! You are in the right place, this course is a great introduction into microbiology, which of course is related to health sciences! Great job in getting a head start! Hope you enjoy and find it engaging and informative!
-
Agnieszka Mrozinska made a comment
API tests
-
Agnieszka Mrozinska made a comment
Childhood illnesses can be often treated without antibiotics, and although the childhood mortality rate went down drastically within last century, this is mostly caused by better access to health care, immunisation programmes (MMR, Whooping cough, TB) as well as general cleanliness and disinfection. Without antibiotics, any surgery could lead to death due to...
-
Agnieszka Mrozinska made a comment
Antimicrobial agents need to be target-specific, ie they need to display toxicity towards bacterial and not human cells. Bacterial ribosomes are different enough from eukaryotic ribosomes, that make good target. Inhibition of protein synthesis have bacteriostatic activity. Destruction of cell wall or membrane has bacteriocidal activity. Bacteriostatic...
-
Agnieszka Mrozinska made a comment
Hello! I am Biomedical Sciences undergraduate at Reading, currently on a placement year at company producing emergency animal vaccines. I do love everything to do with Microbiology and I am looking to refresh and increase my knowledge of resistance.
-
Thank You on behalf of everyone involved! We are glad that you enjoyed the course and looking forward to welcoming you on the campus where you can meet all of the fascinating academics personally- they are truly incredible and make learning experience so pleasurable!
-
Agnieszka Mrozinska replied to Renate R
Thank You Renate for taking part and contribiuting to this course!
-
Agnieszka Mrozinska replied to Hannah Fenlon
Dear Hannah! Primary, good bacteria keep your gut microbiome in check- it grows and colonise your colon, preventing bad bacteria from accessing nutrients and space required for colonisation. Moreover, it can secrete antimicrobial enzymes that prevent growth of pathogenic microbes. Research also suggest that some bacteria help absorption of nutrients and thus...
-
Dear Maria! The fridge door temperature is highly variable- it quickly increases every time you open the door. Main part of fridge is able to maintain temperature better due to its position and proximity to colling apparatus. Every time temperature goes out of range, microbial activity can resume, causing bacterial cells to divide, hence reducing shelf life...
-
Thank You for your comment Chris! Yes, antimicrobial prophylaxis is incredibly dangerous, and many scientists welcomed news few years ago that in Europe farm animals cannot be given antibiotics as a precaution anymore. Scientists, however, have found a way to keep animals safe without risking 'superbugs' making way into our water system of food supply....
-
Agnieszka Mrozinska made a comment
Thank You all for your interesting comments- it is really quite scary to think just how much we depend on microbes. What have really startled me when I first started learning Microbiology is that as a human baby, we are completely colonised within the first 48hours of our birth. Moreover, our microbiota will remain pretty much the same throughout our lives;...
-
Dear Ros! Sequencing used to be a manual, tedious and time consuming work; hence virus, with a much smaller genome than bacteria was an obvious choice to start with!
-
Agnieszka Mrozinska replied to Sue Greenham
Dear Sue! Probiotics, such as Lactobacilli or Bifidobacteria are good for the gut, because they encourage a healthy microbiome. They occupy space in the gut, promote healthy host-bacteria interaction and digestion and inhibit growth of pathogenic bacteria. By using probiotics or pre-biotics (food for good bacteria that encourage growth of prebiotic bacteria)...
-
Glad to hear you are enjoying the course Sue!
-
Agnieszka Mrozinska replied to Philippa Ruegg
Dear Philippa! Viruses probably originated as a mobile genetic materials. We know that RNA molecules can come together in certain conditions; moreover, RNA can replicate itself. This supports the idea, that viruses were the first genome-based entity; moreover, mobile genomic segments- called transposons are still present in eukaryotic organisms, even humans.
-
Agnieszka Mrozinska replied to Sue Greenham
Dear Sue! Thank You for sharing a very intesting deduction process! Very good point!
-
Dear Isla! Yes, patience is a very good skill to have for a Microbiologist ! Slow win the race in this discipline!
-
Dear Maria! You can transfer, insert, or delete genes using a CRISPR-CAS system, which allows for a 'copy and paste' genetic modification. Alternatively, you can transfer genes using plasmids- a circular form of DNA that are not the main chromosome, and often encode virulence or antibiotic resistance genes. This way we can express virulence genes using E.coli;...
-
Agnieszka Mrozinska replied to Hazel R
Dear Hazel! You are right that DNA is a more stable genetic material; however, from a virus point of view, stability is not desired. Viral replication introduced mutations which allows mutation to occur; particles that by chance mutate to be more virulent over compete other viral particles in a process on natural selection. Influenza virus has a single...
-
The HeLa were the first human cell line to be establish and it one of the most known ones; partly due to an ongoing speculation about how it was obtained. This cell line has been obtained from a particularly mutagenic cervical cancer, and as such is extremely prone to mutations. In a healthy human cell, DNA is condensed into 46 chromosomes, whereas the HeLa...
-
Dear Maria! It is great to hear you are enjoying the microbiology! I remember, when I started my degree, I really wanted to buy fancy 1000X magnification light microscope, set of dyes and do it myself! However, I must admit I have quicky given up on the idea- Gram staining is a messy procedure and tend to ruin everything it touches. Having completed two years...
-
Prokaryotic cells also have many mechanisms to adapt and diversify. They can share parts of their genetic material (plasmids) between themselves by a horizontal gene transfer: this is the most common way of spreading of antimicrobial resistance. Bacteria can also alternate their genome by transposition, during which ‘jumping genes’ can change their...
-
Exchange of genetic material is an important aspect of variation, it produces different phenotypes, which two children similar but not identical. The exchange of genetic information in sexual reproduction and further variation due to mutations and epigenetic changes (such as methylation of DNA that can stop or activate expression of genes) certainly drives the...
-
Dear Sophie! Although many protists are dangerous to humans and crops, there are many more harmless that feed on other microbes. Moreover, protists play important role in nutrient recycling in terrestrial, aquatic, and marine ecosystems where they feed on dead and decaying matter (saprophytes). Photoautotrophic protists, similarly, to cyanobacteria, perform...
-
Dear Philipa! You were correct! Only a tiny percentage of microbes is harmful to us!
-
@HazelR Usually we need to be able to grow bacteria in order to obtain a DNA sample from it and multiply it using a Polymerase chain reaction method (PCR) before it can be processed further. This is because bacterial genome is so small. Moreover, we do need to have some idea of bacterial phylum and genus in order to perform a successful PCR run, as we need to...
-
Dear Hazel! No need to apologise, we are more than happy to answer any questions you may have! Bacteria are extremely important in maintaining ecology of soil- they help decomposition of dead material and are involved in carbon and phosphorus cycling as well as fixing nitrogen ( important in photosynthesis). Personally, I have spent one summer collecting...
-
Dear Hannah! I will try to explain it using Escherichia Coli and bacteriophage Lambda as an example. This virus can infect bacterial cell with two possible outcomes: it can either enter a lytic phase, during which it uses host’s machinery to replicate its DNA and produce protein particles until it eventually lyses the cell, killing it. Alternatively, it can...
-
Well done Rachel and Thank You for sharing! Please keep us updated on your results!
-
Agnieszka Mrozinska replied to Courtney Turner
Dear Courtney! I believe that viruses have parasitic characteristics; they do obtain required energy and building blocks from host; often dismantling host's genetic material to access nucleotides to copy their own genome. Nevertheless, they are still classes as not-alive therefore cannot be call a parasite, just as you well noted.
On the point of viruses... -
Dear Jacqueline! What an insightful question! Within the same host, cellular membranes are all very similar and consists of phospholipids, proteins, cholesterol, and sugar molecules. The cell-surface proteins and sugar molecules vary slightly between different cell types; for instance, myelin, an extension of plasma membrane of nerve cells, contains 4 times...
-
Agnieszka Mrozinska made a comment
Open Question: What implication, knowing specific microbes’ growth requirements (Oxygen, temperature, pH) may have? Can you think of any examples how we utilise this knowledge on an everyday basis?
-
Dear Ella! Bacteria does not produce energy directly from iron, but it does require it for growth where iron is an essential co-factor in activating a number of enzymes. Moreover, virulence of some bacteria, such as Actinobacillus pneumoniae, an etiologic agent of porcine pneumonia, is dependent on availability of the molecule. In such cases iron regulates the...
-
Agnieszka Mrozinska replied to Linda Seaborn
Dear Linda! Cellular membrane is made out of fat which makes it hydrophobic- it repels the water and tends to make a spherical shape when dropped into a hydrophilic substance- just like when you pour a drop of oil into water or sand, fatty acids molecules will come together keeping their hydrophilic heads on the outside, and hydrophobic tails on the inside....
-
Dear Robin! Oxygen was first introduced into our atmosphere by cyanobacteria 2.4-2.1 bln years ago. Plants begun to colonise land 465mln years ago, and trees followed suit about 80mln years later. However, the highest levels of oxygen were probably 700mln years ago during Neoproterozoic Oxygenation Event which allowed more complex life forms to develop....
-
Agnieszka Mrozinska replied to laura perez
Hello Laura! Marine Biology sounds very exciting- hope you will find this course engaging and interesting! Please feel free to ask any questions!
-
Hello Sarah! Welcome to the course! It is great to have you here- please feel free to ask any questions you may have or share your experiences.
-
Agnieszka Mrozinska made a comment
Hello everyone! I am Biomedical Sciences student with particular interest in Microbiology. Currenly, I am on a placement year where I get to work with various microbes on a daily basis. I hope you will enjoy the course and find it engaging! We have a great team for this course. Our mentors are on hand from 14th June to 4th July to answer questions and...
-
@LaurenceMorris I am sure the concerns about the lab workers safety are there and are addressed adequately. Public Health England, on advice from WHO produced a Guidance on safe handling and processing samples in laboratories which is being regularly updated. PHE advises that whilst working within the Microbiological Safety Class 2 and 3 cabinets (depending...
-
Dear Michael! Thank You for highlighting the issue. I will pass it onto the course creators.
-
Agnieszka Mrozinska replied to Nithya S
Dear Nithya! Correct- the development of new antibiotic has been impeded by the threat of the resistant bacteria. The problem; however, is not the presence of such microbes, but the risk of their development. Research and clinical trials of new antimicrobials cost hundreds of millions of pounds- sometimes more. Therefore, a significant investment is needed to...
-
Dear Guus! I remember the day I have learnt about SARS and MERS at the University of Reading. I have been very surprised, how virus can appear so quicky, do so much damage and just disappear suddenly. I remember thinking- 'what is next?' . However, at the time, scientific community believed that Influenza outbreak was most probable, looking at history of...
-
Dear Amadu! Our hypothesis would be that the bread with soil added will start decomposing faster due to a presence of microbes within the soil sample, which would be able to grow on bread. However, it all depends on where you got your soil sample from, the condition of the soil( dry will contain more spores than bacteria, which takes time to germinate) and a...
-
Hi Ferina! We are glad to hear you enjoy the course! Hope we will manage to keep you engaged for the next coupe of weeks!
-
Hi Buzz! A very good question indeed! Covid-19 is currently in Biosafety level 3 group; which means a limited access to the lab, a personal protective equipment (not a pressurised suit as in BSL 4) and the majority of the work is completed within an appropriate biosafety cabinet with an air filtration system and directional flow of air. Directional flow is...
-
Agnieszka Mrozinska replied to Kath E
Hello Kath! Good question! Some viruses can indeed insert themself into host's genome and divert the cellular replication machinery for their own expression. When culturing bacteria infected with such virus, we would see opaque plaques on a bacterial lawn. This is because, bacteria is still growing; however, at a reduced rate.
Other viruses, hijack... -
Agnieszka Mrozinska replied to Guus Löhlefink
@JuanF.Schwarze Very interesting question! To answer it, we can indeed look at the bacterial membrane system. The fact that mitochondria possess a double membrane, supports the facts that an aerobic bacterium has been engulfed by an anaerobic archaeon. Moreover, the majority of bacteria possess peptidoglycan in their cell walls, which makes the process of...
-
Hi Michael! Do not worry if you cannot perform the experiment; we can still discuss potential results! Which balloon would you hypothesise to be biggest, which the smallest? Also, can you think of any other factors that can affect the results?
Everyone is welcome to comment! -
Hi Simon! Pathogens that cause gastrointestinal diseases have different infectious doses, which means different amounts of bacteria are required to cause an infection. By monitoring CFU in ready to eat unpasteurised cheese (for example) health officials can assess if the product is safe to eat. A certain number of colonies is acceptable in this instance as...
-
Hi Sharon! Crystal violet is the primary dye, whereas Grams Iodine is a mordant and prevents cells being wash off from the slide. Rinsing off the slide with water directly after crystal violet would leave no cells on the surface for you to study under microscope. Water, however, if necessary to rinse off alcohol to prevent excess decolonization of cells....
-
Welcome Laurence! You will find a very exciting content on environment microbiology later on during the course- I do hope you will enjoy it!
-
Agnieszka Mrozinska replied to Kerrie Doyle
Hello Kerrie and welcome to the course; I hope you will enjoy the course!
-
Agnieszka Mrozinska made a comment
Hello everyone and Welcome to the fascinating learning journey around Microbiology! As you can already see, I am really interested in the world of microorganisms! I am a third year student at the University of Reading currently on a placement year where I spend my days growing various bacteria in fermenters, broths and on plates.
I will be very happy to... -
Hi Osla! Very valid question. When using an attenuated vaccine there is always a risk that the patient may come in contact with a wild form of pathogen, which can lead to infection. This is the case with the Oral Polio Vaccine, where, very rarely, vaccine strains revert into more neurovirulent, infectious strains, causing disease and possibly a localised...
-
Hi Helen! Your comment is very valid. Taking antibiotics for the duration of the course is necessary in prevention of resistance. This is especially important in patients taking very long courses- such as those under treatment for TB, which lasts anything from 3 months to a year.
-
@HelenSchofield Eggs are still used as method for production of Flu vaccine every year!
-
Dear Winifred! It is hard to imagine we could stop future outbreaks from taking place; however, I believe international communication and awareness could indeed prevent another pandemic. WHO still debates on how the current pandemic could be prevented or made less significant, therefore we need to wait for their conclusions. However, what we know so far is...
-
Hello Helen! Bubonic plaque is of zoonotic origin, and it is known that have been transmitted by rats' flees. In human it can then progress into pneumonic plaque, which is transmitted vertically human to human, by air droplets.
The reason why World has been devastated by these outbreaks in middle ages is the progress in urban living. People were moving...
-
Agnieszka Mrozinska replied to [Learner left FutureLearn]
Hi Helen! Autoimmune diseases are caused by body producing antibodies or attacking cells displaying certain molecules- autoantigens. For example, in Rheumatoid arthritis autoantigen is a molecule on surface of synovial joint, and in type I diabetes autoantigen is Pancreatic Beta-cell surface molecule. In both instances, these autoantigens trigger cytotoxic T...
-
Agnieszka Mrozinska replied to [Learner left FutureLearn]
Hi Helen! The usual incubation time is 3-5 days; however, some bacteria grow faster, some slower. This is why the bacteria is plated at various dilutions; it allows us to find a plate with colony number in range of 30-300, independently of speed of growth.
It is important to note, that (especially if microorganism incubated is not identified ) laboratory... -
Hi Carrie! It is called Gram’s iodine after Danish bacteriologist Hans Christian Gram who first used it as a mordant when staining. Gram developed a technique which differentiate bacteria based on their outer membrane and peptidoglycan into Gram- positive and Gram-negative bacteria. The iodine, however, is the same liquid as the antiseptic found in many...
-
Thus, at the beginning of the experiment, we have mixed 50g of mincemeat to the FINAL concentration of 100ml. This means that in 100ml of solution we had 50g of meat. To find dilution factor, we need to divide 50g by 100ml = 0.5
Now, by dividing CFU/ml by 0.5 (the dilution of meat in plated solution) we will calculate how much Colony forming units are... -
@AntoniaCahill Ok! So if we look at the colony count in the quiz (the table) we are given various numbers of colonies present on plate, depending on the dilution which we plated. 1x10^-1 is the smallest dilution (meaning the solution plated is most concentrated) and thus the number of bacteria is so high is uncountable. We are looking for a serial dilution in...
-
@HarryBenitez Thank You for your question. It is undoubtful that the World have lost a high number of bacterial species, and even genera, throughout its evolution and climate changes. However, microbes are very adaptable, and the atmospheric changes did not occur overnight. If we believe in LUCA, we must accept that when for example oxygen become available on...
-
@helengray The way the tree was pinned down to LUCA, is that the genes present both in bacteria, archaea and eukaryotes have been identified: such as ribosomal protein-making genes, forming a proof of common ancestry. Then, by assessing the divergence, loss and acquisition of genetic material, branches have been formed. The number of genes directly inherited...
-
Welcome to the course Aliki and Congratulations on your retirement! No medical or scientific background is required to complete this course; however, curiosity helps enjoyment! Thank you for joining, and please ask if you have any questions- we are here to help!
