Todar's Online Textbook of Bacteriology chapters on bacteriology, microbes in the environment, cycles of elements, bacterial structure, bacterial nutrition, bacterial growth, bacterial metabolism, bacteria and archaea, normal flora, bacterial pathogens, bacterial toxins, endotoxin, antibiotics, antibiotic resistance, staphylococci and MRSA, streptococcus, pneumonia, anthrax, E. coli, cholera, Salmonella, Pseudomonas, Shigella, gonorrhea, meningococcal meningitis, botulism and tetanus hib meningitis, Listeria, whooping cough, B. cereus food poisoning, tuberculosis, diphtheria, Rocky Mountain spotted fever, Lyme disease, Vibrio vulnificus, Bacillus, lactic acid bacteria.
over 6 years ago
Medical Microbiology begins with a review of the immune system, focusing on the body's response to invading microorganisms. Bacteria are then covered, first with a series of chapters presenting the general concepts of bacterial microbiology and then with chapters detailing the major bacterial pathogenes of humans. Similar sections cover virology, mycology, and parasitology. In each section, the introductory chapters stress the mechanisms of infection characteristic of that type of microorganism, thus providing the reader with a framework for understanding rather than memorizing the clinical behavior of the pathogens. The final section of the book Introduction to Infectious Diseases, is arranged by organ system and provides transition for clinical considerations.
over 6 years ago
In the early years of scientific medicine, most clinicians and researchers thought only in terms of single causes: specific agents that cause specific disease. For example, an infection was considered to result only from the proliferation of bacteria, while other kinds of ill health might result from viruses, toxins, accidents, or flaws in a person's genetic makeup. More recent research highlights the relationships between health and behavioral, psychological, and social variables.
over 6 years ago
Which bacteria could cause urinary tract infections but would not show up on a normal urine culture?
Some bacteria species (such as Mycoplasma) are difficult to culture using standard methods. Could these bacteria cause a urinary tract infection in the absence of a positive urine culture? If so, how can these infections be diagnosed in a patient with only general symptoms of cystitis? What other hard-to-culture species besides Mycoplasma can cause urinary tract infections?
over 8 years ago
When is it medically advisable to eat some one else's poo? When you need a poo transplant. Poo transplants could be the solution to one of the biggest problems facing the NHS today- the bacterial infection Clostridium difficile. C.diff, as it's known to its friends, infects about 18,000 people in England and Wales every year and is involved in the deaths of about 2000 people. C.diff typically arises due to imbalances in the normal gut bacteria. The gut is like a city, a city with about 100 trillion bacterial residents happily munching away on a banquet of bowel contents. The average person has about 1000 different types of bacteria in their gut, and about 3% of healthy adults have C.diff in that mix. The C.diff doesn't cause them any problems because its numbers are kept in check by the other gut bacteria. However treatment with broad spectrum antibiotics such as clindamycin, cephalosporins, ciprofloxacin and co-amoxiclav, can disrupt this happy community- killing off vast swathes of bacteria but crucially not the C.diff. Given free rein the C.diff multiplies rapidly and produces toxins which damage the gut. In some people this causes mild diarrhoea and abdominal pain, in others it can lead to torrential diarrhoea, perforation of the colon and death. Traditional treatment includes stopping any broad spectrum antibiotics and possibly prescribing antibiotics which target the C.diff such as metronidazole or vancomycin. However with antibiotic use comes the risk of resistance. Moreover our current approach isn't entirely effective and about 22% of patients treated suffer a recurrence. This can result in a cycle of illness and hospital admission which is costly to the patient and the hospital. So it's time to start thinking outside of the box. Cue the poo transplant. The thinking goes like this- if the cause of the problem is disruption to the normal community of gut bacteria, why not just pop those bacteria back in to crowd out the C.diff? Simples. Practically, the first step is to identify a donor, usually a close relative of the patient, and screen them for a range of infectious diseases and parasites. It's also advisable to make sure they haven't recently consumed anything the intended recipient is allergic to, before asking them to make their "donation". You then pop it in a household blender and blitz it down, adding saline or milk to achieve a slurry consistency. Next you need to strain your concoction to remove large materials- one medic in the UK uses coffee filters. Top tip. Then you're ready to administer it- about 25ml from above (e.g. via nasogastric tube), or 250ml from below. Now, its important to note that poo transplants are still an experimental treatment. To date only small case studies have been carried out, but with 200 total reported cases, an average cure rate of 96% and no serious adverse events reported to date, it's worth carrying out a large trial to assess it thoroughly. Poo transplants- arguably the ideal treatment for a cash strapped NHS. It's cheap, plentiful and it seems to work. Now to convince people to consume someone else's poo... Bottoms up! FYI: This was first posted on my own blog. Image Courtesy of Marcus007 at de.wikipedia [Public domain], from Wikimedia Commons
Dr Catherine Carver
almost 8 years ago
Maybe it’s just me, but I cannot get my head around pharmacology and antibiotics are certainly doing their best to finish me off! My group at uni decided that this was one area that we needed to revise, and the task fell on my hands to provide the material for a revision session. So, the night before the session I began to panic about how to come up with any useful tips for my group, or indeed anyone at all, to try to remember anything useful about antibiotics at all. If only Paracetamoxyfrusebendroneomycin was a real drug, it would make our lives so much easier. Come on Adam Kay and Suman Biswas, get the trials started and create your wonderful super drug. For the mean time I guess I will just have to keep blissfully singing along to your song. However, that is not going to help me with my task in hand. After a lot of research that even took me beyond the realms of Wikipedia (something I do not often like to do), I found various sources suggesting remembering these Top 10 Rules (and their exceptions) All cell wall inhibitors are ?-lactams (except vancomycin) All penicillins are water soluble (nafcillin) All protein synthesis inhibitors are bacteriostatic (aminoglycosides) All cocci are Gram positive (Neisseria spp.) All bacilli are Gram negative (anthrax, tetanus, botulism, diptheria) All spirochetes are Gram negative Tetracyclines and macrolides are used for intracellular bacteria Pregnant women should not take tetracyclines, aminoglycosides, fluroquinolones, or sulfonamides Antibiotics beginning with a ‘C’ are particularly associated with pseudomembranous colitis While the penicillins are the most famous for causing allergies, people may also react to cephalosporins If those work for you, then I guess you can stop reading now… If they don’t, I can’t promise that I have anything better, but give these other tips that I found a whirl… Alternatively, I have created a Page on my own blog called Rang and Dale’s answer to Antibiotics, which summarises their information, so please take a look at that. Most people will suggest that you can categorise antibiotics in three ways, and it’s best to pick one and learn examples of them. Mode of action: bactericidal (kill) bacteriostatic (stop multiplying) 2 mnemonics to potentially help you remember examples: We’re ECSTaTiC about bacteriostatics? Erythromycin Clindamycin Sulphonamides Tetracyclines Trimethoprim Chloramphenicol Very Finely Proficient At Cell Murder (bactericidal) - Vancomycin Fluroquinolones Penicillins Aminoglycosides Cephalosporins Metranidazole Spectrum of activity: broad-spectrum (gram positive AND negative) narrow (gram positive OR negative) Mechanism of action Inhibit cell wall synthesis Inhibit nucleic acid synthesis Inhibit protein synthesis Inhibit cell membrane synthesis If you have any more weird and wonderful ways to remember antibiotics, let me know and I will add them! As always, thank you for reading.
Mrs Malaika Smith
over 7 years ago
BOXING Day, 1.30am. “Are you the doctor on call?” I wrenched my reluctant brain from its REM state. “Yes.” “I’m worried about my wife. She’s 16 weeks pregnant and very gassy.” “Gassy?” “Burping and farting. Smells terrible! It’s keeping us both awake. I’m worried it could be serious.” By the time I ascertained that there were no sinister symptoms and that the likely culprit was the custard served with Christmas pudding (the patient was lactose intolerant), I was wide awake. My brain refused to power down for hours, as if out of spite for being so rudely aroused. I have a confession to make. When the Australian Federal Government announced that it was planning to abolish after-hours practice incentive payments, I was delighted. I know, I know, I should have been outraged along with the rest of you. After all, the RACGP predicted that after-hours care would be decimated if incentives were removed. Comparisons were made with the revamp of the UK system in 2004, which led to 90% of the profession opting out of after-hours work. Much as I sympathised, I was secretly rubbing my hands together with selfish glee. Surely this would mean that our semi-rural practice would stop doing all of our own on-call and free me from my after-hours responsibilities? I detest being on call. I loathe it with a passion completely out of proportion to the imposition it actually causes. I’m on call for the practice and our local hospital only once a week and the workload isn’t onerous. Middle-of-the-night calls aren’t all that frequent, but my sleep can be disturbed by their mere possibility, leaving me tired and cranky. If I’m forced suddenly into “brain on, work mode” by a phone call, I can kiss hours of precious slumber goodbye. I love to sleep, but, as with drawing and tennis, I’m not very good at it. I gaze with envy at those lucky devils who nap on public transport and fight malicious urges to disturb their peaceful repose. If I’m not supine, in a quiet, warm room, with loose-fitting clothing, a firm mattress and a pillow shaped just-so, I can forget any chance of sleep. Let’s just say I can relate to the Princess and the Pea story. I bet she wouldn’t have coped well with being phoned in the middle of the night either. If these nocturnal calls were all bona fide emergencies, I wouldn’t mind so much. It’s the crap that really riles me. I’ve received middle-of-the-night phone calls from patients who are constipated, patients with impacted cerumen (“Me ear’s blocked, Doc. I can’t sleep”) and patients with insomnia who want to know if it’s safe to take a second sedative. The call that took the on-call cake for me, though, was from a couple who woke me at 11.30 one night to settle an argument. “My husband says that bacteria are more dangerous than viruses but I reckon viruses are worse. After all, AIDS is a virus. Can you settle it for us so we can get some sleep? It would really help us out.” I kid you not. Genevieve Yates is an Australian GP, medical educator, medico-legal presenter and writer. You can read more of her work at http://genevieveyates.com
Dr Genevieve Yates
over 7 years ago
When you think of the term 'bacteria', it immediately conjures up an image of a faceless, ruthless enemy-one that requires your poor body to maintain constant vigilance, fighting the good fight forever and always. And should you happen to lose the battle, well, the after effects are always messy. But what some people might not know is that bacteria are our silent saviours as well. These 'good' bacteria are known as probiotics, where 'pro' means 'for' and 'bios' is 'life'. The WHO defines probiotics as "live micro-organisms which, when administered in adequate amounts, confer a health bene?t on the host". Discovered by the Russian scientist Metchnikoff in the 20th century; simply put, probiotics are micro-organisms such as bacteria or yeast, which improve the health of an individual. Our bodies contain more than 500 different species of bacteria which serve to maintain our health by keeping harmful pathogens in check, supporting the immune system and helping in digestion and absorption of nutrients. From the very first breath you take, you are exposed to probiotics. How so? As an infant passes through it's mother's birth canal, it receives a good dose of healthy bacteria, which in turn serve to populate it's own gastro-intestinal tract. However, unfortunately, as we go through life, our exposure to overly processed foods, anti-bacterial products, sterilized and pasteurized food etc, might mean that in our zeal to have everything sanitary and hygienic, we might be depriving ourselves of the beneficial effects of such microorganisms. For any health care provider, the focus should not only be on eradicating disease but improving overall health as well. Here, probiotic containing foods and supplements play an important role as they not only combat diseases but also confer better health in general. Self dosing yourself with bacteria might sound a little bizarre at first-after all, we take antibiotics to fight bacteria. But let's not forget that long before probiotics became a viable medical option, our grandparents (and their parents before them) advocated the intake of yoghurt drinks (lassi). The fermented milk acts as an instant probiotic delivery system to the body! Although they are still being studied, probiotics may help several specific illnesses, studies show. They have proven useful in treating childhood diarrheas as well as antibiotic associated diarrhea. Clinical trial results are mixed, but several small studies suggest that certain probiotics may help maintain remission of ulcerative colitis and prevent relapse of Crohn’s disease and the recurrence of pouchitis (a complication of surgery during treatment of ulcerative colitis). They may also help to maintain a healthy urogenital system, preventing problems such as vaginitis and UTIs. Like all things, probiotics may have their disadvantages too. They are considered dangerous for people with impaired immune systems and one must take care to ensure that the correct strain of bacteria related to their required health benefit is present in such supplements. But when all is said and done and all the pros and cons of probiotics are weighed; stand back ladies and gentlemen, there's a new superhero in town, and what's more-it's here to stay!
over 7 years ago