Ask a room of PMB 201 students which host the malaria parasite reproduces sexually in and half of them will confidently say the human. It is the mosquito. That one slip, definitive host against intermediate host, is the kind of small trap this course sets again and again: Gram-positive against Gram-negative, DNA virus against RNA virus, a mould against a yeast, parasitism against commensalism. Get the distinctions clean and the paper stops feeling like a memory test. This page is a student-written study companion for PMB 201 – Pharmaceutical Microbiology, a compulsory course for ABUAD 200 Level Pharmacy students in the first semester, College of Pharmacy.
Microbiology rewards the student who organises rather than the one who crams, because almost every topic is a small world with its own vocabulary and a handful of comparisons the examiner loves. The syllabus runs from the founders of the field and the bacterial cell, through viruses and the wall-less oddballs, into fungi and finishes with parasites and the drugs that treat them. The summaries below turn that syllabus into plain-English notes, with original practice questions and worked reasoning so you can check each idea has landed. The full workbook sits in the interactive reader at the end as a free bonus to the notes on this page.
- Course: PMB 201 – Pharmaceutical Microbiology
- College / Department: College of Pharmacy, Pharmaceutical Microbiology
- Level / Semester: 200 Level, First Semester
- Topics covered: Scope and history of microbiology, prokaryotes against eukaryotes, the surface and internal features of the bacterial cell, cell wall chemistry and the Gram stain, the bacterial spore, classification of bacteria, viral structure and replication, HIV and the coronaviruses, chlamydia, rickettsia and mycoplasma, introduction to fungi and their classification, fungal infections and the uses of fungi in pharmacy, then introductory parasitology: host relationships, the protozoa and helminths, and antiparasitic drugs
- Best for: Continuous assessment + final exam revision
Part One: Foundations of Pharmaceutical Microbiology
1. What Pharmaceutical Microbiology Studies
Microbiology is the study of living things too small for the naked eye, which is why it waited on the microscope to become a science. The name comes from three Greek roots, mikros for small, bios for life and logos for study, so the word itself tells you it is the study of microscopic life. The subject looks at the form, structure, reproduction, metabolism and classification of microbes, and at how they spread through nature and change the world around them.
For a pharmacist the point is practical, not academic. Microbes sit on both sides of the ledger: they spoil and contaminate medicines, yet they also give us penicillin, vaccines, interferon and many industrial products. The field splits into branches by the organism studied, phycology for algae, mycology for fungi, virology for viruses, protozoology for protozoa, alongside industrial, food and water, and environmental microbiology. Exam tip: keep the branch-and-focus pairs as a short table and be ready to give the two faces of microbial life, the harmful and the useful, since a "why does a pharmacist study microbes" opener is common.
2. The People Who Built the Science
Five names carry most of the history marks. Antony van Leeuwenhoek, a Dutch draper who ground his own lenses, was the first to see and sketch bacteria in the 1680s, calling them animalcules. Louis Pasteur, often named the father of microbiology, showed that microbes drive fermentation, used his swan-necked flask to disprove spontaneous generation, gave us pasteurisation (gentle heating to roughly 62.8°C), separated aerobic from anaerobic life, and made the first attenuated vaccines against fowl cholera, anthrax and rabies.
Joseph Lister brought antiseptic surgery and the first pure culture by dilution. Robert Koch proved that a specific microbe causes a specific disease, worked out the anthrax and tuberculosis bacilli, and introduced solid media and the streak plate. His four postulates run: the organism is in every diseased host, it grows in pure culture, that culture reproduces the disease in a healthy host, and it is recovered again from that host. Alexander Fleming closes the story, spotting in 1928 that a stray Penicillium notatum mould had killed the staphylococci around it, which opened the antibiotic age. Exam tip: memorise Koch's four postulates in order as a set, and tie each scientist to one signature contribution, because "match the scientist to the discovery" is a reliable structured question.
Part Two: The Bacterial Cell
3. Two Cell Types: Prokaryotes and Eukaryotes
The deepest division in biology is not plant against animal but prokaryote against eukaryote. A memory hook reads the Greek literally: pro-karyote means "before the nucleus" and eu-karyote means "true nucleus". Prokaryotes are the bacteria, simple single cells with no true nucleus and no membrane-bound organelles, their DNA usually a single circular chromosome lying free in a region called the nucleoid. Eukaryotes, the cells of animals, plants, fungi and protists, pack several linear chromosomes into a membrane-bound nucleus and carry organelles like mitochondria and a Golgi apparatus.
The contrasts are the exam. Prokaryotes are small (about 0.1 to 5 µm), divide by binary fission and lack sexual reproduction; eukaryotes are larger (10 to 100 µm), divide by mitosis or meiosis and usually reproduce sexually. In a bacterium the plasma membrane doubles as the site of transport, biosynthesis and energy generation, work that a eukaryote hands to dedicated organelles. Exam tip: build a two-column table with rows for nucleus, genome, organelles, size and division, then reproduce it from memory, because "distinguish prokaryotes from eukaryotes" is almost guaranteed.
4. Surface Features of the Bacterial Cell
The outer features give a bacterium its shape and its dealings with the world: moving, sticking, resisting osmotic stress and dodging host defences. The cell wall is a rigid peptidoglycan layer that fixes shape and stops the cell bursting. Beneath it, the plasma membrane controls what enters and leaves and runs respiration. A capsule or slime layer is a gel coat that guards against drying and phagocytosis and helps the cell attach and form biofilm. Flagella are whip-like tails for motility, and pili are short protein hairs that anchor the cell to host tissue, with sex pili passing DNA during conjugation.
Flagella earn their own classification by number and position, and it doubles as an identification aid: atrichous means none (as in Corynebacterium diphtheriae), monotrichous is a single polar flagellum (Vibrio cholerae), lophotrichous is a tuft at one pole (Pseudomonas), amphitrichous is flagella at both poles, and peritrichous is all over the surface (Bacillus). Exam tip: learn the five flagellar arrangements with one named example each, and pair each surface structure with its single main function, since that pairing is where the marks sit.
5. Inside the Bacterial Cell
Prokaryotes have no membrane-bound organelles, but their cytoplasm still holds specialised parts. The cytoplasm itself is a semi-fluid gel of water, enzymes and salts where reactions like glycolysis happen. The nucleoid is the irregular region carrying the single circular chromosome. Plasmids are small separate loops of DNA that often carry extras such as antibiotic resistance and move between cells by horizontal transfer, which also makes them handy cloning vectors. Ribosomes, the 70S type in bacteria, translate messenger RNA into protein.
The rest are worth a line each: inclusion bodies store carbon, phosphate or sulfur (magnetosomes even help orientation), mesosomes are membrane infoldings tied to wall building and DNA replication chiefly in Gram-positives, and endospores are the dormant survival bodies of Bacillus and Clostridium. Exam tip: note that the bacterial ribosome is 70S while the eukaryotic one is 80S, because that difference is exactly why some antibiotics hit bacteria and spare us, and remember plasmids as the usual carrier of resistance genes.
6. Cell Wall Chemistry and the Gram Stain
The wall is built around peptidoglycan, a mesh of sugar chains of N-acetylmuramic acid and N-acetylglucosamine cross-linked by short peptides. This "chain-link fence" holds shape and stops the cell lysing. Peptidoglycan is found only in prokaryotes, and the transpeptidase enzymes that cross-link it are the target of the beta-lactam antibiotics like penicillin. Other wall pieces matter too: teichoic and lipoteichoic acids are antigenic polymers of Gram-positives, while lipopolysaccharide (LPS), with its lipid A, core and O-antigen, is the outer-membrane molecule of Gram-negatives and the source of endotoxin.
The two wall designs explain the Gram stain. Gram-positive cells have a thick peptidoglycan layer and keep the dye; Gram-negative cells have a thin layer plus an outer LPS membrane and lose it. The four steps run in order: flood with crystal violet, fix with Gram's iodine mordant, decolourise briefly with alcohol or acetone, then counterstain with safranin so Gram-positives read purple and Gram-negatives read pink. Because it depends on peptidoglycan, the stain fails on archaea, on eukaryotes, and on wall-less bacteria. Exam tip: write the four steps as a numbered sequence and attach the colour result to each wall type, then remember that a decolourisation left too long turns a true Gram-positive falsely pink.
7. The Bacterial Spore
An endospore is a dormant, extremely tough survival body made by two Gram-positive genera, the aerobic Bacillus and the anaerobic Clostridium. When a cell meets starvation, extreme pH or radiation it undergoes sporulation, converting itself into a spore; when conditions improve the spore germinates back to the vegetative state. The structure is layered from a dehydrated core (only 10 to 25% water, rich in dipicolinic acid, calcium and protective SASP proteins) out through inner membrane, germ cell wall, a thick cortex, outer membrane, a keratin-like coat and sometimes an exosporium.
That build is why spores resist almost everything. The low core water blocks heat denaturation, the DPA and calcium complex with the SASPs shield the DNA, and dormancy leaves few active targets for drugs. In numbers: spores survive boiling for hours but die in an autoclave at 121°C for 15 minutes, need 160 to 170°C for 1 to 2 hours by dry heat, and shrug off alcohols and phenolics while yielding to aldehydes and chlorine dioxide. This is the whole reason Bacillus stearothermophilus spores are used to validate autoclaves and why Clostridium difficile demands sporicidal cleaning. Exam tip: learn the autoclave figure (121°C, 15 min) cold, and be ready to say in one line why the low core water content drives heat resistance.
8. How Bacteria Are Classified
Bacteria are grouped in several overlapping ways. The oldest is by shape: cocci are spheres (and are described further by grouping, from pairs to grape-like clusters), bacilli are rods, vibrios are short curved commas, and spirilla are rigid spirals. Cohn set out this scheme back in 1872 and it still opens most identification. Each shape carries a standard example, Staphylococcus aureus for cocci, Vibrio cholerae for the comma form.
Beyond shape, bacteria are sorted by physiology. By nutrition they are phototrophs or chemotrophs, autotrophs or heterotrophs, with most pathogens heterotrophic. By temperature they are psychrophiles, mesophiles (optimum near 37°C, where most pathogens sit), thermophiles or hyperthermophiles. By oxygen need they run from obligate aerobes to obligate anaerobes, with facultative anaerobes, aerotolerant anaerobes and microaerophiles between. Further schemes use pH, osmotic tolerance, spore formation and flagella, and the Gram stain itself is one of the most useful of all. Exam tip: keep one worked classification you can reel off (shape, oxygen, temperature) and remember that "mesophile, optimum 37°C" describes most human pathogens, a fact examiners like to test.
Part Three: Viruses and the Wall-Less Bacteria
9. What a Virus Is
A virus is an obligate intracellular parasite: a strand of nucleic acid, either DNA or RNA but never both, wrapped in a protein coat and sometimes a lipid envelope. It has no metabolism of its own and can multiply only inside a host cell, showing signs of life within a cell yet sitting inert outside one. Sizes run roughly 20 to 300 nm, too small for a light microscope, and each virus infects only a limited range of host cells.
The intact particle is the virion. Its nucleic-acid core sits inside a protein capsid built of repeating capsomers, the two together forming the nucleocapsid; enveloped viruses add a host-derived membrane studded with glycoprotein spikes for attachment. Capsids take one of two symmetries, helical (rod-like) or icosahedral (a twenty-faced shell that packs the most genome into the least protein). Viruses are classified into species, genera, families and orders by nucleic-acid type, symmetry and envelope. Two agents are simpler still: viroids are naked RNA circles that infect plants, and prions are infectious proteins with no nucleic acid at all. Exam tip: the "DNA or RNA but never both" line is a favourite one-mark point, and be ready to contrast helical against icosahedral symmetry and viroids against prions.
10. How Viruses Replicate
Because a virus cannot reproduce alone, it hijacks a host. The bacteriophages that infect bacteria show the pattern most clearly. The lytic cycle runs in five stages: adsorption (tail fibres bind host receptors), penetration (lysozyme opens the wall and DNA is injected while the empty capsid stays outside), replication (host synthesis is switched off and redirected), assembly (heads and tails are built then joined), and release (the cell bursts, freeing 50 to 200 new virions). In the lysogenic cycle the phage DNA instead integrates quietly into the host genome as a prophage and is copied at each division until a stress like UV light triggers it back into the lytic route.
Animal viruses vary with their genome. A positive-sense RNA acts straight away as messenger RNA, while a negative-sense RNA must first be copied to the positive sense by a viral polymerase. Retroviruses like HIV carry reverse transcriptase, which builds a DNA copy of their RNA that is then integrated as a provirus, and unlike a prophage that provirus is never excised, which is how the infection becomes lifelong. Exam tip: memorise the five lytic stages in order and pin down the single difference between lysogeny and the retroviral provirus, that the prophage can leave but the provirus stays, because that comparison is prime exam material.
11. Medically Important Viruses: HIV and the Coronaviruses
HIV is a retrovirus that causes AIDS by destroying the CD4+ T-helper cells at the centre of immunity; as their count falls the body opens up to opportunistic infection. Its life cycle is a set-piece answer: gp120 attaches to the CD4 receptor with a co-receptor, gp41 fuses the envelope to the membrane, reverse transcriptase copies the RNA to DNA, integrase splices that DNA in as a provirus, the host reads it to make new virus, and fresh virions bud off to infect more cells. Error-prone reverse transcription drives the rapid mutation that frustrates both the immune system and drugs, and two strains exist, the widespread HIV-1 and the milder HIV-2.
Coronaviruses are enveloped positive-sense RNA viruses whose crown of spike proteins names the family. In people they range from common colds to the severe syndromes SARS (2002), MERS (2012) and COVID-19 (2019). The spike protein handles binding and fusion, with SARS viruses using the ACE2 receptor and MERS using DPP4, and spread is chiefly by respiratory droplets. Every COVID-19 vaccine strategy targets that spike: mRNA vaccines deliver its genetic code, viral-vector vaccines carry the gene in a harmless adenovirus, and inactivated vaccines use whole killed virus. Exam tip: rehearse the HIV cycle as six named steps and remember the receptor pairings (HIV to CD4, SARS to ACE2, MERS to DPP4), since precise receptor names separate a full mark from a partial one.
12. Chlamydia, Rickettsia and Mycoplasma
These three are bacteria that break the textbook rules, which is exactly why they are grouped together and why they resist certain drugs. Chlamydiae are obligate intracellular bacteria with no peptidoglycan and a two-stage life cycle: the tough, infectious elementary body enters a cell and converts into the larger, active reticulate body, which multiplies then reverts to elementary bodies for release. Chlamydia trachomatis is the leading infectious cause of blindness and a common sexually transmitted infection. Rickettsiae are small Gram-negative obligate intracellular bacteria spread by arthropod bites and droppings, causing the spotted fevers and typhus.
Mycoplasmas are the odd one out with no cell wall at all, so they barely take the Gram stain and are naturally resistant to wall-targeting drugs such as penicillins and cephalosporins; Mycoplasma pneumoniae causes the atypical "walking" pneumonia. The clean comparison is by wall and lifestyle: chlamydia has no peptidoglycan and lives inside cells, rickettsia has a Gram-negative wall and lives inside cells, mycoplasma has no wall and lives outside cells, and wall-acting antibiotics work only on the rickettsia. Exam tip: the reason mycoplasma resists penicillin, that it has no wall for the drug to attack, is a favourite short answer, so state it plainly and keep the three-way wall-and-lifestyle table ready.
Part Four: Fungi and Their Role in Pharmacy
13. An Introduction to Fungi
The study of fungi is mycology. Fungi are eukaryotes with a rigid cell wall that feed as heterotrophs, and they matter to pharmacy because they both cause disease and produce many of our drugs. Apart from the single-celled yeasts, most fungi are filamentous, growing as thread-like hyphae that weave into a mesh called a mycelium. Their wall is made of chitin rather than the cellulose of plants or the peptidoglycan of bacteria, a detail that helps explain why antibacterial antibiotics do nothing against them.
Fungi are non-vascular, non-motile heterotrophs, unicellular or multicellular, that reproduce by spores and lack chlorophyll, so they cannot photosynthesise. They sit between plants and animals: like plants they have a cell wall and no locomotion, but like animals they have sterols in the membrane and cannot make their own food. By nutrition they are saprophytic (feeding on dead matter, as Penicillium and Aspergillus do), parasitic (drawing from a living host) or symbiotic (as in lichens and mycorrhizae). Exam tip: remember chitin as the fungal wall material and be ready to place fungi against plants and animals on a trait table, since "are fungi plants or animals" is a standard discussion question.
14. The Groups of Pathogenic Fungi
Pathogenic fungi fall into a few recognisable groups. Yeasts are single cells that reproduce by budding and form smooth colonies, with Candida albicans and Cryptococcus neoformans the clinical names to know. Moulds are multicellular, growing fuzzy colonies of hyphae and reproducing by spores, Aspergillus being the classic example. Mushrooms are the fleshy fruiting bodies, some highly toxic like the death cap Amanita phalloides.
Two groups are worth extra care. Dimorphic fungi live as a mould in the environment but switch to a yeast inside the host, a temperature-driven change seen in Histoplasma and Coccidioides. Dermatophytes live on keratin and cause the superficial Tinea infections, ringworm and athlete's foot. One warning belongs here: Nocardia and Actinomyces look fungal and were once classed as fungi, but they are bacteria and respond only to antibacterials. Exam tip: anchor the yeast-against-mould split (budding single cells against filamentous hyphae) and define dimorphism as the mould-in-cold, yeast-in-host switch, because those two distinctions carry most of the marks here.
15. Fungal Infections
Fungal infections, the mycoses, tend to strike immunocompromised patients, run a slow subacute to chronic course, and mostly do not pass from person to person, the dermatophytes being the notable exception. Ordinary antibacterial antibiotics are useless against them. They are classified by how deep into the body they reach, which is the framework the exam wants.
Superficial mycoses stay on the outer skin, hair and nails, the various Tinea infections of scalp, body and feet. Mucocutaneous mycoses hit the mucous membranes, as in oral thrush and vaginal candidiasis. Subcutaneous mycoses sit beneath the skin, sporotrichosis being the "rose-gardener's disease". Deep or systemic mycoses reach the internal organs, from pulmonary histoplasmosis to cryptococcal meningitis and Candida endocarditis in the vulnerable. Exam tip: learn the four depth categories in order with one example each, and remember the general rule that mycoses favour immunocompromised hosts and resist antibacterials, since that framing opens most fungal-infection answers.
16. Why Fungi Matter in Pharmacy
Fungi earn their place in pharmacy above all as drug factories. Penicillin, the first antibiotic, comes from Penicillium chrysogenum and kills Gram-positive bacteria; the related actinomycete Streptomyces griseus gives streptomycin against Gram-negatives. Griseofulvin, from Penicillium griseofulvum, treats ringworm and athlete's foot. Beyond antibiotics, ergot alkaloids from Claviceps purpurea drive uterine contraction (and are the source of LSD), ergosterol from moulds is a source of vitamin D, and yeasts supply B-complex vitamins such as riboflavin.
The single biggest contribution is the manufacture of antimicrobials, and the related actinomycetes widen the net further with chloramphenicol, aureomycin and terramycin. That is worth stating outright in an exam, because a question on the importance of fungi is really asking you to lead with the antibiotics and then list a few named products and their uses. Exam tip: memorise a short product-source-use table (penicillin, griseofulvin, ergot alkaloids, riboflavin) and open any "importance of fungi" answer with antimicrobial production, since that is the marked headline.
Part Five: Introductory Parasitology
17. Hosts and Parasites
Parasitology deals with parasites and their hosts. A parasite lives on or in a host at the host's expense, and it is best understood against the wider set of symbiotic relationships: parasitism helps one and harms the host (Plasmodium in humans), commensalism helps one and leaves the other unaffected (Entamoeba coli in the gut), and mutualism benefits both partners (the termite and its gut protozoa). Sorting a relationship into the right box is a common opening mark.
Hosts come in types that trip students in the malaria example. The definitive host carries the adult or sexually reproducing stage, while the intermediate host carries the larval or asexual stage. For malaria the Anopheles mosquito is the definitive host (the sexual stage happens in it) and the human is the intermediate host, which is the exact reverse of most students' first guess. Parasites are also split by habitat into ectoparasites on the surface and endoparasites inside, and by dependence into obligate and facultative. Exam tip: fix the malaria case in memory, mosquito as definitive host and human as intermediate, because it is both the classic trap and an easy mark once you have it straight.
18. The Kinds of Parasite
Medically important parasites fall into two main camps plus the vectors that carry them. Protozoa are microscopic single-celled eukaryotes, divided into four classes by how they move: amoebae with pseudopods, flagellates with flagella, ciliates with cilia, and sporozoa with no locomotor organelle at all (the group that includes the malaria parasite). Helminths are the macroscopic multicellular worms, and they split into three: nematodes or roundworms (Ascaris), cestodes or tapeworms (Taenia), and trematodes or flukes (Schistosoma).
Arthropods complete the picture as vectors, and the distinction between two vector types is worth holding: a biological vector is essential to the parasite's life cycle, as the mosquito is for malaria, whereas a mechanical vector merely carries the parasite from place to place, as the housefly does in amoebiasis. Exam tip: learn the four protozoan classes by their means of movement and the three helminth groups with one example each, then keep the biological-against-mechanical vector distinction sharp, since it is a frequent one-line question.
19. Where Parasites Come From and How We Treat Them
Parasitic infection has predictable sources: soil (swallowed eggs or larvae boring through skin, as hookworm does), water (infective forms in contaminated water), food (faecally contaminated produce, or undercooked meat carrying larvae such as Taenia and Trichinella), insect vectors (biological or mechanical), and animal reservoirs (cattle for beef tapeworm, dogs for hydatid disease, cats for toxoplasmosis). Knowing the source often points straight to prevention.
Treatment rests mainly on chemotherapy. The drugs of choice are worth memorising as pairings: metronidazole (or tinidazole and ornidazole) for amoebic colitis, giardiasis and trichomoniasis; chloroquine for uncomplicated benign malaria; artemisinin derivatives, quinine and mefloquine for complicated or falciparum malaria; primaquine for relapse of vivax malaria; and praziquantel for all tapeworm and fluke infections. The guiding rule is that rational therapy depends on identifying both the parasite and its life-cycle stage, since the acute attack, the radical cure of dormant stages and prophylaxis can each call for a different drug. Exam tip: build a drug-against-indication table and note especially why primaquine is added in vivax malaria, that it clears the dormant liver stage the other drugs miss, because that "why two drugs" point is a common probe.
Sample Practice Questions (With Answers)
Here are a few representative questions, written in our own words, with the reasoning explained so you understand the why, not just the answer:
Q1. A smear is stained by the Gram method but the technician leaves the alcohol on far too long. A truly Gram-positive organism reads pink. What went wrong, and why?
Answer: Over-decolourisation. The decolourising step (alcohol or acetone) is meant to be brief: the thick peptidoglycan of a Gram-positive cell should trap the crystal violet and iodine complex, while the thin-walled Gram-negative cell releases it. Left too long, alcohol also strips the dye from the Gram-positive wall, so it then takes up the safranin counterstain and shows falsely pink. The lesson is that Gram-stain reliability rests on controlling that single timing step.
Q2. Why is penicillin useless against Mycoplasma pneumoniae, and what does that tell you about how penicillin works?
Answer: Mycoplasmas have no cell wall at all, and penicillin acts by blocking the transpeptidase enzymes that cross-link peptidoglycan in the wall. With no wall and no peptidoglycan to target, the drug has nothing to attack, so mycoplasmas are intrinsically resistant to penicillins and cephalosporins. It confirms that beta-lactam antibiotics are wall-synthesis inhibitors, which is also why they harm bacteria but not our own (wall-less) cells.
Q3. A lecturer says the HIV provirus and a bacteriophage prophage are alike but not the same. Explain the key difference and its consequence.
Answer: Both integrate their genetic material into the host chromosome, the prophage in a temperate phage and the provirus in a retrovirus like HIV. The difference is exit: a prophage can be excised from the host genome by induction (for example after UV exposure) and enter the lytic cycle, whereas the HIV provirus is never excised. Because it stays put, HIV establishes a lifelong, chronic infection that current drugs suppress but do not clear.
Q4. In the malaria life cycle, which is the definitive host and which is the intermediate host, and how do you decide?
Answer: The Anopheles mosquito is the definitive host and the human is the intermediate host. The rule is that the definitive host carries the sexually reproducing (adult) stage of the parasite, while the intermediate host carries the asexual (larval) stage. Since the parasite's sexual stage takes place in the mosquito, the mosquito is definitive despite our instinct to name the human, whose body only hosts the asexual stage.
Q5. An autoclave is validated with a biological indicator rather than a chemical one. Which organism is used and why does it fit the job?
Answer: Spores of Bacillus stearothermophilus are used. A validating indicator must be harder to kill than anything the cycle is meant to destroy, and bacterial endospores are the most heat-resistant life form because of their dehydrated, dipicolinic-acid-rich core. If a cycle of 121°C for 15 minutes kills these spores, it will kill ordinary vegetative cells too, so their death confirms the autoclave works.
Q6. Distinguish a yeast from a mould, and define what makes a fungus dimorphic.
Answer: A yeast is a single-celled fungus that reproduces by budding and forms smooth colonies, as Candida albicans does. A mould is multicellular, growing as filamentous hyphae into fuzzy colonies and reproducing by spores, as Aspergillus does. A dimorphic fungus shows both forms depending on conditions: it grows as a mould in the cooler environment but converts to a yeast at body temperature inside the host, seen in Histoplasma and Coccidioides.
Q7. Why is primaquine added to treatment for Plasmodium vivax malaria when chloroquine has already been given?
Answer: Chloroquine clears the blood-stage parasites and treats the acute attack, but P. vivax also forms dormant liver stages that chloroquine does not reach. Primaquine is added to destroy those dormant liver forms and so achieve radical cure, preventing later relapse. It illustrates the general parasitology rule that different life-cycle stages can each need their own drug.
How to Study PMB 201 Effectively
- Lead with the vocabulary, because microbiology is examined on precise terms. Build a running glossary (nucleoid, peptidoglycan, endospore, provirus, dimorphic, definitive host) and be able to define each in one clean sentence.
- Turn every comparison into a small table and reproduce it from a blank page: prokaryote against eukaryote, Gram-positive against Gram-negative, DNA against RNA virus, yeast against mould, and the chlamydia, rickettsia and mycoplasma trio.
- Memorise the short ordered sequences as complete sets: Koch's four postulates, the four Gram-stain steps, the five stages of the lytic cycle, and the six-step HIV life cycle.
- Attach one named example to every category, because the applied name is often the mark: Vibrio cholerae for monotrichous, Candida albicans for a yeast, Anopheles for the malaria vector, Bacillus stearothermophilus for autoclave validation.
- Learn the numbers that examiners love: the autoclave setting (121°C for 15 minutes), the 70S bacterial ribosome, and the receptor pairings (HIV to CD4, SARS to ACE2).
- Read the summaries here first, then work through the full workbook in the reader below and attempt the practice questions from memory before your exam.
Download the Full PMB 201 Practice Workbook
The notes above already walk the whole syllabus, but if you want everything gathered in one place, the full PMB 201 – Pharmaceutical Microbiology workbook is loaded in the reader just below: the prokaryote-against-eukaryote and Gram comparison tables, the labelled spore structure and its resistance data, the DNA and RNA virus families, the fungal classification and pharmaceutical-product charts, and the parasite and antiparasitic-drug tables. Flip through it right here on the page, or save a copy so you can keep drilling the distinctions and the named examples offline in the days before your paper.
Frequently Asked Questions
Is this PMB 201 material free?
It is. There is no paywall, sign-up or fee here; the PMB 201 notes, practice questions and downloadable workbook are open to any student who needs them.
Do I need to memorise every organism name for PMB 201?
You need the key ones, not all of them. Focus on the standard example attached to each category, one flagellar arrangement, one yeast, one mould, the malaria vector, the autoclave indicator, because those named examples are where structured marks are won. Learn the concepts first, then hang a couple of solid examples on each.
Will these exact questions appear in my exam?
They will not. Every question in the practice set was written from scratch for revision, so use it to rehearse the reasoning and the method, not as a forecast of what your lecturer will actually set.
What is the fastest way to revise PMB 201 before the paper?
Rebuild the comparison tables from memory (prokaryote against eukaryote, Gram-positive against Gram-negative, the wall-less trio), recite the short ordered lists such as Koch's postulates and the lytic cycle, and drill one named example per category. Finish by attempting the practice questions without looking and reading the full workbook in the reader below.
About this resource: All summaries, explanations, study tips, and practice questions on this page were written, paraphrased, and adapted by the EverythingABUAD student team to support exam revision. This is an original study aid, not an official ABUAD document, and it is not a prediction of any future exam. Always cross-check with your lecturer's current course outline.
