[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › Microbiology # Microbiology and Parasitology Every microorganism the exams ask about, on one page: what it looks like, how it spreads, how it causes disease, how it is diagnosed, which drug class treats it and how it is prevented. With what matters in Colombia and the tropics, and linked to DurgiPedia's conditions. 178 microorganisms in 31 groups - Bacteria - Viruses - Fungi - Parasites - Colombia and the tropics - A to Z ## Colombia and the tropics The microorganisms that weigh most in the exams and in public health in Colombia. - [Ascaris lumbricoides](https://durgical.com/en/microbiology/ascaris-lumbricoides/) - [Candida albicans](https://durgical.com/en/microbiology/candida-albicans/) - [Chikungunya virus](https://durgical.com/en/microbiology/chikungunya-virus/) - [Chlamydia trachomatis](https://durgical.com/en/microbiology/chlamydia-trachomatis/) - [Clostridium tetani](https://durgical.com/en/microbiology/clostridium-tetani/) - [Cryptococcus neoformans](https://durgical.com/en/microbiology/cryptococcus-neoformans/) - [Dengue virus](https://durgical.com/en/microbiology/dengue-virus/) - [Entamoeba histolytica](https://durgical.com/en/microbiology/entamoeba-histolytica/) - [Enterobius vermicularis](https://durgical.com/en/microbiology/enterobius-vermicularis/) - [Escherichia coli](https://durgical.com/en/microbiology/escherichia-coli/) - [Giardia duodenalis](https://durgical.com/en/microbiology/giardia-duodenalis/) - [Helicobacter pylori](https://durgical.com/en/microbiology/helicobacter-pylori/) - [Hepatitis A virus](https://durgical.com/en/microbiology/hepatitis-a-virus/) - [Hepatitis B virus](https://durgical.com/en/microbiology/hepatitis-b-virus/) - [Histoplasma capsulatum](https://durgical.com/en/microbiology/histoplasma-capsulatum/) - [Human immunodeficiency virus](https://durgical.com/en/microbiology/human-immunodeficiency-virus/) - [Human papillomavirus](https://durgical.com/en/microbiology/human-papillomavirus/) - [Influenza virus](https://durgical.com/en/microbiology/influenza-virus/) - [Leishmania (Viannia) panamensis, L. braziliensis and L. guyanensis](https://durgical.com/en/microbiology/leishmania-panamensis-l-braziliensis-and-l-guyanensis/) - [Leishmania infantum](https://durgical.com/en/microbiology/leishmania-infantum/) - [Leptospira interrogans](https://durgical.com/en/microbiology/leptospira-interrogans/) - [Measles virus](https://durgical.com/en/microbiology/measles-virus/) - [Mycobacterium tuberculosis](https://durgical.com/en/microbiology/mycobacterium-tuberculosis/) - [Necator americanus / Ancylostoma duodenale](https://durgical.com/en/microbiology/necator-americanus-ancylostoma-duodenale/) - [Neisseria gonorrhoeae](https://durgical.com/en/microbiology/neisseria-gonorrhoeae/) - [Neisseria meningitidis](https://durgical.com/en/microbiology/neisseria-meningitidis/) - [Plasmodium falciparum](https://durgical.com/en/microbiology/plasmodium-falciparum/) - [Plasmodium vivax](https://durgical.com/en/microbiology/plasmodium-vivax/) - [Rabies virus](https://durgical.com/en/microbiology/rabies-virus/) - [Salmonella Typhi](https://durgical.com/en/microbiology/salmonella-typhi/) - [Sarcoptes scabiei](https://durgical.com/en/microbiology/sarcoptes-scabiei/) - [SARS-CoV-2](https://durgical.com/en/microbiology/sars-cov-2/) - [Staphylococcus aureus](https://durgical.com/en/microbiology/staphylococcus-aureus/) - [Streptococcus pneumoniae](https://durgical.com/en/microbiology/streptococcus-pneumoniae/) - [Streptococcus pyogenes](https://durgical.com/en/microbiology/streptococcus-pyogenes/) - [Strongyloides stercoralis](https://durgical.com/en/microbiology/strongyloides-stercoralis/) - [Taenia solium](https://durgical.com/en/microbiology/taenia-solium/) - [Toxoplasma gondii](https://durgical.com/en/microbiology/toxoplasma-gondii/) - [Treponema pallidum](https://durgical.com/en/microbiology/treponema-pallidum/) - [Trichuris trichiura](https://durgical.com/en/microbiology/trichuris-trichiura/) - [Trypanosoma cruzi](https://durgical.com/en/microbiology/trypanosoma-cruzi/) - [Vibrio cholerae](https://durgical.com/en/microbiology/vibrio-cholerae/) - [Yellow fever virus](https://durgical.com/en/microbiology/yellow-fever-virus/) - [Zika virus](https://durgical.com/en/microbiology/zika-virus/) ## Bacteria - [**Other clinically important bacteria** Eight bacteria outside the big groups that still show up in exams: anaerobes, bites, seafood, the hospital, Whipple and the non-venereal treponemes. Bacteroides fragilis · Haemophilus ducreyi · Pasteurella multocida · Burkholderia cepacia complex and Burkholderia pseudomallei · Vibrio vulnificus and Vibrio parahaemolyticus · Enterobacter, Serratia and Citrobacter · Tropheryma whipplei · Non-venereal treponemes (yaws, bejel and pinta)](https://durgical.com/en/microbiology/groups/other-clinically-important-bacteria/) - [**Gram-negative cocci** Coffee-bean diplococci: meningococcus, gonococcus and Moraxella. They cause meningitis, gonorrhea, ear and sinus infections. Neisseria meningitidis · Neisseria gonorrhoeae · Moraxella catarrhalis](https://durgical.com/en/microbiology/groups/gram-negative-cocci/) - [**Enterobacterales** Gut rods such as E. coli, Salmonella, Shigella, Klebsiella, Proteus and Yersinia: diarrhea, urinary infection and sepsis. Escherichia coli · Salmonella Typhi · Non-typhoidal Salmonella · Shigella · Klebsiella pneumoniae · Proteus mirabilis · Yersinia](https://durgical.com/en/microbiology/groups/enterobacterales/) - [**Other Gram-negative rods** Curved rods, coccobacilli and non-fermenters: H. pylori, Vibrio, Pseudomonas, Haemophilus, Bordetella, Legionella and the zoonoses. Helicobacter pylori · Vibrio cholerae · Campylobacter jejuni · Pseudomonas aeruginosa · Acinetobacter baumannii · Haemophilus influenzae · Bordetella pertussis · Legionella pneumophila · Bartonella · Brucella · Francisella tularensis · Gardnerella vaginalis](https://durgical.com/en/microbiology/groups/other-gram-negative-rods/) - [**Staphylococci** Gram-positive cocci in clusters that live on skin and in the nose; S. aureus is the most aggressive and MRSA the most feared in hospitals. Staphylococcus aureus · Staphylococcus epidermidis · Staphylococcus saprophyticus](https://durgical.com/en/microbiology/groups/staphylococci/) - [**Streptococci and enterococci** Gram-positive cocci in chains or pairs that cause anything from sore throat and pneumonia to newborn sepsis and endocarditis. Streptococcus pyogenes · Streptococcus pneumoniae · Streptococcus agalactiae · Viridans streptococci · Enterococcus](https://durgical.com/en/microbiology/groups/streptococci-and-enterococci/) - [**Gram-positive rods** Gram-positive rods: spore-forming clostridia and bacilli, corynebacteria, Listeria and the branching Nocardia and Actinomyces. Clostridium tetani · Clostridioides difficile · Clostridium botulinum · Clostridium perfringens · Corynebacterium diphtheriae · Listeria monocytogenes · Bacillus anthracis · Bacillus cereus · Nocardia · Actinomyces israelii](https://durgical.com/en/microbiology/groups/gram-positive-rods/) - [**Mycobacteria** Rods with a lipid-rich wall that resists acid-alcohol: they cause tuberculosis, leprosy and environmental infections. Mycobacterium tuberculosis · Mycobacterium leprae · Mycobacterium avium complex and other non-tuberculous mycobacteria](https://durgical.com/en/microbiology/groups/mycobacteria/) - [**Spirochetes** Long, spiral bacteria that move like a corkscrew: syphilis, leptospirosis, Lyme disease and relapsing fever. Treponema pallidum · Leptospira interrogans · Borrelia burgdorferi · Borrelia recurrentis and tick-borne relapsing fever borreliae](https://durgical.com/en/microbiology/groups/spirochetes/) - [**Intracellular and atypical bacteria** Bacteria that live inside cells or lack a wall: Chlamydia, Rickettsia, Coxiella, Ehrlichia and Mycoplasma. Chlamydia trachomatis · Mycoplasma pneumoniae · Chlamydia pneumoniae / Chlamydia psittaci · Rickettsia rickettsii / Rickettsia typhi · Mycoplasma genitalium / Ureaplasma · Coxiella burnetii · Ehrlichia / Anaplasma · Orientia tsutsugamushi](https://durgical.com/en/microbiology/groups/intracellular-and-atypical-bacteria/) ## Viruses - [**Other viruses and prions** Childhood respiratory viruses, haemorrhagic fevers, rodent-borne viruses, mosquito-borne encephalitis and prions, which are not viruses. Parainfluenza virus · Human metapneumovirus · Ebola and Marburg viruses (filoviruses) · Hantavirus · Arenaviruses (Lassa and the South American haemorrhagic fevers) · Equine encephalitis viruses and Mayaro virus · West Nile virus · Prions](https://durgical.com/en/microbiology/groups/other-viruses-and-prions/) - [**Human herpesviruses** Enveloped DNA viruses that, after the first infection, stay latent for life and can reactivate. Herpes simplex virus 1 · Herpes simplex virus 2 · Varicella-zoster virus · Epstein–Barr virus · Cytomegalovirus · Human herpesviruses 6 and 7 · Human herpesvirus 8](https://durgical.com/en/microbiology/groups/human-herpesviruses/) - [**Other DNA viruses** DNA viruses that are not herpesviruses: hepadna-, papilloma-, polyoma-, parvo-, adeno- and poxviruses. Hepatitis B virus · Human papillomavirus · JC polyomavirus · Parvovirus B19 · Adenovirus · Mpox virus · Molluscum contagiosum virus · Variola virus](https://durgical.com/en/microbiology/groups/other-dna-viruses/) - [**RNA arboviruses** Viruses spread by the bites of arthropods (mosquitoes, midges). In Colombia they cause dengue, Zika, chikungunya, yellow fever and Oropouche fever. Dengue virus · Zika virus · Chikungunya virus · Yellow fever virus · Oropouche virus](https://durgical.com/en/microbiology/groups/rna-arboviruses/) - [**RNA hepatitis viruses** RNA viruses that attack the liver: A and E through water and food; C and D through blood. Hepatitis B, a DNA virus, completes the list. Hepatitis A virus · Hepatitis C virus · Hepatitis D virus · Hepatitis E virus](https://durgical.com/en/microbiology/groups/rna-hepatitis-viruses/) - [**Respiratory RNA viruses** RNA viruses that enter through the airway: influenza, RSV, SARS-CoV-2, rhinovirus and the rash viruses measles, rubella and mumps. Influenza virus · Respiratory syncytial virus · Measles virus · Mumps virus · Rubella virus · SARS-CoV-2 · Rhinovirus](https://durgical.com/en/microbiology/groups/respiratory-rna-viruses/) - [**Other RNA viruses** Retroviruses (HIV, HTLV-1), rabies virus and the enteric viruses: rotavirus, norovirus and enteroviruses such as poliovirus. Human immunodeficiency virus · Human T-lymphotropic virus type 1 · Rabies virus · Rotavirus · Norovirus · Enteroviruses](https://durgical.com/en/microbiology/groups/other-rna-viruses/) ## Fungi - [**Yeasts and yeast-like fungi** Single-celled fungi that reproduce by budding: Candida and Cryptococcus cause the most common opportunistic mycoses in hospitals and in HIV. Candida albicans · Cryptococcus neoformans · Pneumocystis jirovecii · Malassezia](https://durgical.com/en/microbiology/groups/yeasts-and-yeast-like-fungi/) - [**Dimorphic fungi** Fungi that live as molds in soil and switch to yeasts inside the body; acquired by inhaling spores, they cause the endemic mycoses. Histoplasma capsulatum · Paracoccidioides brasiliensis · Sporothrix schenckii · Coccidioides immitis · Blastomyces dermatitidis](https://durgical.com/en/microbiology/groups/dimorphic-fungi/) - [**Molds and dermatophytes** Filamentous fungi: environmental molds that attack the immunosuppressed, and dermatophytes that feed on the keratin of skin, hair and nails. Aspergillus fumigatus · Mucorales (Rhizopus, Mucor) · Dermatophytes (Trichophyton, Microsporum, Epidermophyton) · Agents of chromoblastomycosis (Fonsecaea and other pigmented fungi)](https://durgical.com/en/microbiology/groups/molds-and-dermatophytes/) - [**Other fungi of clinical interest** Three loose chapters of the textbook: mycetoma of the foot, Talaromyces in AIDS in Asia, and microsporidia, now grouped with the fungi. Mycetoma agents · Talaromyces marneffei · Microsporidia (Enterocytozoon, Encephalitozoon)](https://durgical.com/en/microbiology/groups/other-fungi-of-clinical-interest/) ## Parasites - [**Nematodes** Roundworms: gut worms caught from soil (soil-transmitted helminths), pinworms, and tissue worms such as filariae, Toxocara and Trichinella. Ascaris lumbricoides · Necator americanus / Ancylostoma duodenale · Strongyloides stercoralis · Trichuris trichiura · Enterobius vermicularis · Toxocara canis / Toxocara cati · Ancylostoma braziliense / Ancylostoma caninum · Wuchereria bancrofti / Brugia malayi · Onchocerca volvulus · Trichinella spiralis · Mansonella ozzardi / Mansonella perstans](https://durgical.com/en/microbiology/groups/nematodes/) - [**Cestodes (tapeworms)** Flat, segmented worms with no gut. Humans can host the adult tapeworm in the bowel or, worse, its larva in tissues. Taenia solium · Taenia saginata · Echinococcus granulosus · Hymenolepis nana · Dibothriocephalus latus](https://durgical.com/en/microbiology/groups/cestodes/) - [**Trematodes (flukes)** Leaf-shaped flatworms that need a snail to complete their cycle. They arrive with raw plants, fish or crabs, or through the skin in fresh water. Fasciola hepatica · Schistosoma mansoni / S. haematobium / S. japonicum · Paragonimus spp. · Clonorchis sinensis / Opisthorchis spp.](https://durgical.com/en/microbiology/groups/trematodes/) - [**Ectoparasites** Arthropods living on or in the skin: the scabies mite, lice, the chigoe flea and fly larvae that cause myiasis. Sarcoptes scabiei · Pediculus humanus and Pthirus pubis · Tunga penetrans · Dermatobia hominis](https://durgical.com/en/microbiology/groups/ectoparasites/) - [**Other parasites of interest** Seven parasites that exams ask about even though they are rare: from the harmless trypanosome that mimics Chagas to the Guinea worm. Trypanosoma rangeli · Loa loa · Dracunculus medinensis · Angiostrongylus (A. costaricensis, A. cantonensis) · Gnathostoma and Anisakis · Lagochilascaris minor · Dipylidium caninum](https://durgical.com/en/microbiology/groups/other-parasites-of-interest/) - [**Arthropod vectors** The insects that carry dengue, malaria, leishmaniasis and Chagas in Colombia: how they live, how they bite and how they are controlled. Aedes aegypti and Aedes albopictus · Anopheles · Lutzomyia · Triatomines (Rhodnius prolixus, Triatoma dimidiata)](https://durgical.com/en/microbiology/groups/arthropod-vectors/) - [**Hemoflagellates (trypanosomes and Leishmania)** Flagellated protozoa with a kinetoplast that live in blood or inside cells, spread by insects: kissing bugs, sand flies and the tsetse fly. Trypanosoma cruzi · Leishmania (Viannia) panamensis, L. braziliensis and L. guyanensis · Leishmania infantum · Trypanosoma brucei gambiense and T. b. rhodesiense](https://durgical.com/en/microbiology/groups/hemoflagellates/) - [**Apicomplexans** Intracellular protozoa with an apical complex for invading cells: Plasmodium, Toxoplasma, Cryptosporidium, Cyclospora, Cystoisospora and Babesia. Plasmodium vivax · Plasmodium falciparum · Plasmodium malariae and Plasmodium ovale · Toxoplasma gondii · Cryptosporidium spp. · Cyclospora cayetanensis and Cystoisospora belli · Babesia spp.](https://durgical.com/en/microbiology/groups/apicomplexans/) - [**Intestinal and urogenital protozoa** Amoebae, flagellates and ciliates of the gut and genital tract: Entamoeba, Giardia, Blastocystis, Balantioides, commensal amoebae and Trichomonas. Entamoeba histolytica · Giardia duodenalis · Trichomonas vaginalis · Blastocystis spp. · Balantioides coli · Commensal intestinal amoebae (Entamoeba coli, E. dispar, Endolimax nana and others)](https://durgical.com/en/microbiology/groups/intestinal-and-urogenital-protozoa/) - [**Free-living amoebae** Water and soil amoebae that rarely infect people, but cause severe meningoencephalitis or keratitis when they do. Naegleria fowleri · Acanthamoeba spp.](https://durgical.com/en/microbiology/groups/free-living-amoebae/) ## A to Z - **[Acanthamoeba spp.](https://durgical.com/en/microbiology/acanthamoeba-spp/)** Free-living amoebae - **[Acinetobacter baumannii](https://durgical.com/en/microbiology/acinetobacter-baumannii/)** Other Gram-negative rods Gram-negative - Contact - **[Actinomyces israelii](https://durgical.com/en/microbiology/actinomyces-israelii/)** Gram-positive rods Gram-positive - **[Adenovirus](https://durgical.com/en/microbiology/adenovirus/)** Other DNA viruses Non-enveloped (naked) - Contact - Droplet - **[Aedes aegypti and Aedes albopictus](https://durgical.com/en/microbiology/aedes-aegypti-and-aedes-albopictus/)** Arthropod vectors - **[Agents of chromoblastomycosis (Fonsecaea and other pigmented fungi)](https://durgical.com/en/microbiology/agents-of-chromoblastomycosis/)** Molds and dermatophytes - **[Ancylostoma braziliense / Ancylostoma caninum](https://durgical.com/en/microbiology/ancylostoma-braziliense-ancylostoma-caninum/)** Nematodes - **[Angiostrongylus (A. costaricensis, A. cantonensis)](https://durgical.com/en/microbiology/angiostrongylus/)** Other parasites of interest - **[Anopheles](https://durgical.com/en/microbiology/anopheles/)** Arthropod vectors - **[Arenaviruses (Lassa and the South American haemorrhagic fevers)](https://durgical.com/en/microbiology/arenaviruses/)** Other viruses and prions Enveloped - Contact - Droplet - **[Ascaris lumbricoides](https://durgical.com/en/microbiology/ascaris-lumbricoides/)** Nematodes - **[Aspergillus fumigatus](https://durgical.com/en/microbiology/aspergillus-fumigatus/)** Molds and dermatophytes - **[Babesia spp.](https://durgical.com/en/microbiology/babesia-spp/)** Apicomplexans - **[Bacillus anthracis](https://durgical.com/en/microbiology/bacillus-anthracis/)** Gram-positive rods Gram-positive - **[Bacillus cereus](https://durgical.com/en/microbiology/bacillus-cereus/)** Gram-positive rods Gram-positive - **[Bacteroides fragilis](https://durgical.com/en/microbiology/bacteroides-fragilis/)** Other clinically important bacteria Gram-negative - **[Balantioides coli](https://durgical.com/en/microbiology/balantioides-coli/)** Intestinal and urogenital protozoa - **[Bartonella](https://durgical.com/en/microbiology/bartonella/)** Other Gram-negative rods Gram-negative - **[Blastocystis spp.](https://durgical.com/en/microbiology/blastocystis-spp/)** Intestinal and urogenital protozoa - **[Blastomyces dermatitidis](https://durgical.com/en/microbiology/blastomyces-dermatitidis/)** Dimorphic fungi - **[Bordetella pertussis](https://durgical.com/en/microbiology/bordetella-pertussis/)** Other Gram-negative rods Gram-negative - Droplet - **[Borrelia burgdorferi](https://durgical.com/en/microbiology/borrelia-burgdorferi/)** Spirochetes Does not Gram-stain - **[Borrelia recurrentis and tick-borne relapsing fever borreliae](https://durgical.com/en/microbiology/borrelia-recurrentis-and-tick-borne-relapsing-fever-borreliae/)** Spirochetes Does not Gram-stain - **[Brucella](https://durgical.com/en/microbiology/brucella/)** Other Gram-negative rods Gram-negative - **[Burkholderia cepacia complex and Burkholderia pseudomallei](https://durgical.com/en/microbiology/burkholderia-cepacia-complex-and-burkholderia-pseudomallei/)** Other clinically important bacteria Gram-negative - Contact - **[Campylobacter jejuni](https://durgical.com/en/microbiology/campylobacter-jejuni/)** Other Gram-negative rods Gram-negative - Contact - **[Candida albicans](https://durgical.com/en/microbiology/candida-albicans/)** Yeasts and yeast-like fungi - **[Chikungunya virus](https://durgical.com/en/microbiology/chikungunya-virus/)** RNA arboviruses Enveloped - **[Chlamydia pneumoniae / Chlamydia psittaci](https://durgical.com/en/microbiology/chlamydia-pneumoniae-chlamydia-psittaci/)** Intracellular and atypical bacteria Gram-negative - **[Chlamydia trachomatis](https://durgical.com/en/microbiology/chlamydia-trachomatis/)** Intracellular and atypical bacteria Gram-negative - **[Clonorchis sinensis / Opisthorchis spp.](https://durgical.com/en/microbiology/clonorchis-sinensis-opisthorchis-spp/)** Trematodes (flukes) - **[Clostridioides difficile](https://durgical.com/en/microbiology/clostridioides-difficile/)** Gram-positive rods Gram-positive - Contact - **[Clostridium botulinum](https://durgical.com/en/microbiology/clostridium-botulinum/)** Gram-positive rods Gram-positive - **[Clostridium perfringens](https://durgical.com/en/microbiology/clostridium-perfringens/)** Gram-positive rods Gram-positive - **[Clostridium tetani](https://durgical.com/en/microbiology/clostridium-tetani/)** Gram-positive rods Gram-positive - **[Coccidioides immitis](https://durgical.com/en/microbiology/coccidioides-immitis/)** Dimorphic fungi - **[Commensal intestinal amoebae (Entamoeba coli, E. dispar, Endolimax nana and others)](https://durgical.com/en/microbiology/commensal-intestinal-amoebae/)** Intestinal and urogenital protozoa - **[Corynebacterium diphtheriae](https://durgical.com/en/microbiology/corynebacterium-diphtheriae/)** Gram-positive rods Gram-positive - Droplet - Contact - **[Coxiella burnetii](https://durgical.com/en/microbiology/coxiella-burnetii/)** Intracellular and atypical bacteria Gram-negative - **[Cryptococcus neoformans](https://durgical.com/en/microbiology/cryptococcus-neoformans/)** Yeasts and yeast-like fungi - **[Cryptosporidium spp.](https://durgical.com/en/microbiology/cryptosporidium-spp/)** Apicomplexans - **[Cyclospora cayetanensis and Cystoisospora belli](https://durgical.com/en/microbiology/cyclospora-cayetanensis-and-cystoisospora-belli/)** Apicomplexans - **[Cytomegalovirus](https://durgical.com/en/microbiology/cytomegalovirus/)** Human herpesviruses Enveloped - **[Dengue virus](https://durgical.com/en/microbiology/dengue-virus/)** RNA arboviruses Enveloped - **[Dermatobia hominis](https://durgical.com/en/microbiology/dermatobia-hominis/)** Ectoparasites - **[Dermatophytes (Trichophyton, Microsporum, Epidermophyton)](https://durgical.com/en/microbiology/dermatophytes/)** Molds and dermatophytes - **[Dibothriocephalus latus](https://durgical.com/en/microbiology/dibothriocephalus-latus/)** Cestodes (tapeworms) - **[Dipylidium caninum](https://durgical.com/en/microbiology/dipylidium-caninum/)** Other parasites of interest - **[Dracunculus medinensis](https://durgical.com/en/microbiology/dracunculus-medinensis/)** Other parasites of interest - **[Ebola and Marburg viruses (filoviruses)](https://durgical.com/en/microbiology/ebola-and-marburg-viruses/)** Other viruses and prions Enveloped - Contact - Droplet - Airborne - **[Echinococcus granulosus](https://durgical.com/en/microbiology/echinococcus-granulosus/)** Cestodes (tapeworms) - **[Ehrlichia / Anaplasma](https://durgical.com/en/microbiology/ehrlichia-anaplasma/)** Intracellular and atypical bacteria Gram-negative - **[Entamoeba histolytica](https://durgical.com/en/microbiology/entamoeba-histolytica/)** Intestinal and urogenital protozoa - **[Enterobacter, Serratia and Citrobacter](https://durgical.com/en/microbiology/enterobacter-serratia-and-citrobacter/)** Other clinically important bacteria Gram-negative - Contact - **[Enterobius vermicularis](https://durgical.com/en/microbiology/enterobius-vermicularis/)** Nematodes - **[Enterococcus](https://durgical.com/en/microbiology/enterococcus/)** Streptococci and enterococci Gram-positive - Contact - **[Enteroviruses](https://durgical.com/en/microbiology/enteroviruses/)** Other RNA viruses Non-enveloped (naked) - Contact - **[Epstein–Barr virus](https://durgical.com/en/microbiology/epstein-barr-virus/)** Human herpesviruses Enveloped - **[Equine encephalitis viruses and Mayaro virus](https://durgical.com/en/microbiology/equine-encephalitis-viruses-and-mayaro-virus/)** Other viruses and prions Enveloped - **[Escherichia coli](https://durgical.com/en/microbiology/escherichia-coli/)** Enterobacterales Gram-negative - Contact - **[Fasciola hepatica](https://durgical.com/en/microbiology/fasciola-hepatica/)** Trematodes (flukes) - **[Francisella tularensis](https://durgical.com/en/microbiology/francisella-tularensis/)** Other Gram-negative rods Gram-negative - **[Gardnerella vaginalis](https://durgical.com/en/microbiology/gardnerella-vaginalis/)** Other Gram-negative rods Gram-variable - **[Giardia duodenalis](https://durgical.com/en/microbiology/giardia-duodenalis/)** Intestinal and urogenital protozoa - **[Gnathostoma and Anisakis](https://durgical.com/en/microbiology/gnathostoma-and-anisakis/)** Other parasites of interest - **[Haemophilus ducreyi](https://durgical.com/en/microbiology/haemophilus-ducreyi/)** Other clinically important bacteria Gram-negative - **[Haemophilus influenzae](https://durgical.com/en/microbiology/haemophilus-influenzae/)** Other Gram-negative rods Gram-negative - Droplet - **[Hantavirus](https://durgical.com/en/microbiology/hantavirus/)** Other viruses and prions Enveloped - **[Helicobacter pylori](https://durgical.com/en/microbiology/helicobacter-pylori/)** Other Gram-negative rods Gram-negative - **[Hepatitis A virus](https://durgical.com/en/microbiology/hepatitis-a-virus/)** RNA hepatitis viruses Non-enveloped (naked) - Contact - **[Hepatitis B virus](https://durgical.com/en/microbiology/hepatitis-b-virus/)** Other DNA viruses Enveloped - **[Hepatitis C virus](https://durgical.com/en/microbiology/hepatitis-c-virus/)** RNA hepatitis viruses Enveloped - **[Hepatitis D virus](https://durgical.com/en/microbiology/hepatitis-d-virus/)** RNA hepatitis viruses Enveloped - **[Hepatitis E virus](https://durgical.com/en/microbiology/hepatitis-e-virus/)** RNA hepatitis viruses Non-enveloped (naked) - Contact - **[Herpes simplex virus 1](https://durgical.com/en/microbiology/herpes-simplex-virus-1/)** Human herpesviruses Enveloped - **[Herpes simplex virus 2](https://durgical.com/en/microbiology/herpes-simplex-virus-2/)** Human herpesviruses Enveloped - Contact - **[Histoplasma capsulatum](https://durgical.com/en/microbiology/histoplasma-capsulatum/)** Dimorphic fungi - **[Human herpesvirus 8](https://durgical.com/en/microbiology/human-herpesvirus-8/)** Human herpesviruses Enveloped - **[Human herpesviruses 6 and 7](https://durgical.com/en/microbiology/human-herpesviruses-6-and-7/)** Human herpesviruses Enveloped - **[Human immunodeficiency virus](https://durgical.com/en/microbiology/human-immunodeficiency-virus/)** Other RNA viruses Enveloped - **[Human metapneumovirus](https://durgical.com/en/microbiology/human-metapneumovirus/)** Other viruses and prions Enveloped - Contact - **[Human papillomavirus](https://durgical.com/en/microbiology/human-papillomavirus/)** Other DNA viruses Non-enveloped (naked) - **[Human T-lymphotropic virus type 1](https://durgical.com/en/microbiology/human-t-lymphotropic-virus-type-1/)** Other RNA viruses Enveloped - **[Hymenolepis nana](https://durgical.com/en/microbiology/hymenolepis-nana/)** Cestodes (tapeworms) - **[Influenza virus](https://durgical.com/en/microbiology/influenza-virus/)** Respiratory RNA viruses Enveloped - Droplet - **[JC polyomavirus](https://durgical.com/en/microbiology/jc-polyomavirus/)** Other DNA viruses Non-enveloped (naked) - **[Klebsiella pneumoniae](https://durgical.com/en/microbiology/klebsiella-pneumoniae/)** Enterobacterales Gram-negative - Contact - **[Lagochilascaris minor](https://durgical.com/en/microbiology/lagochilascaris-minor/)** Other parasites of interest - **[Legionella pneumophila](https://durgical.com/en/microbiology/legionella-pneumophila/)** Other Gram-negative rods Gram-negative - **[Leishmania (Viannia) panamensis, L. braziliensis and L. guyanensis](https://durgical.com/en/microbiology/leishmania-panamensis-l-braziliensis-and-l-guyanensis/)** Hemoflagellates (trypanosomes and Leishmania) - **[Leishmania infantum](https://durgical.com/en/microbiology/leishmania-infantum/)** Hemoflagellates (trypanosomes and Leishmania) - **[Leptospira interrogans](https://durgical.com/en/microbiology/leptospira-interrogans/)** Spirochetes Does not Gram-stain - **[Listeria monocytogenes](https://durgical.com/en/microbiology/listeria-monocytogenes/)** Gram-positive rods Gram-positive - **[Loa loa](https://durgical.com/en/microbiology/loa-loa/)** Other parasites of interest - **[Lutzomyia](https://durgical.com/en/microbiology/lutzomyia/)** Arthropod vectors - **[Malassezia](https://durgical.com/en/microbiology/malassezia/)** Yeasts and yeast-like fungi - **[Mansonella ozzardi / Mansonella perstans](https://durgical.com/en/microbiology/mansonella-ozzardi-mansonella-perstans/)** Nematodes - **[Measles virus](https://durgical.com/en/microbiology/measles-virus/)** Respiratory RNA viruses Enveloped - Airborne - **[Microsporidia (Enterocytozoon, Encephalitozoon)](https://durgical.com/en/microbiology/microsporidia/)** Other fungi of clinical interest - **[Molluscum contagiosum virus](https://durgical.com/en/microbiology/molluscum-contagiosum-virus/)** Other DNA viruses Enveloped - **[Moraxella catarrhalis](https://durgical.com/en/microbiology/moraxella-catarrhalis/)** Gram-negative cocci Gram-negative - **[Mpox virus](https://durgical.com/en/microbiology/mpox-virus/)** Other DNA viruses Enveloped - Contact - Airborne - **[Mucorales (Rhizopus, Mucor)](https://durgical.com/en/microbiology/mucorales/)** Molds and dermatophytes - **[Mumps virus](https://durgical.com/en/microbiology/mumps-virus/)** Respiratory RNA viruses Enveloped - Droplet - **[Mycetoma agents](https://durgical.com/en/microbiology/mycetoma-agents/)** Other fungi of clinical interest - **[Mycobacterium avium complex and other non-tuberculous mycobacteria](https://durgical.com/en/microbiology/mycobacterium-avium-complex-and-other-non-tuberculous-mycobacteria/)** Mycobacteria Acid-fast - **[Mycobacterium leprae](https://durgical.com/en/microbiology/mycobacterium-leprae/)** Mycobacteria Acid-fast - **[Mycobacterium tuberculosis](https://durgical.com/en/microbiology/mycobacterium-tuberculosis/)** Mycobacteria Acid-fast - Airborne - **[Mycoplasma genitalium / Ureaplasma](https://durgical.com/en/microbiology/mycoplasma-genitalium-ureaplasma/)** Intracellular and atypical bacteria Does not Gram-stain - **[Mycoplasma pneumoniae](https://durgical.com/en/microbiology/mycoplasma-pneumoniae/)** Intracellular and atypical bacteria Does not Gram-stain - Droplet - **[Naegleria fowleri](https://durgical.com/en/microbiology/naegleria-fowleri/)** Free-living amoebae - **[Necator americanus / Ancylostoma duodenale](https://durgical.com/en/microbiology/necator-americanus-ancylostoma-duodenale/)** Nematodes - **[Neisseria gonorrhoeae](https://durgical.com/en/microbiology/neisseria-gonorrhoeae/)** Gram-negative cocci Gram-negative - **[Neisseria meningitidis](https://durgical.com/en/microbiology/neisseria-meningitidis/)** Gram-negative cocci Gram-negative - Droplet - **[Nocardia](https://durgical.com/en/microbiology/nocardia/)** Gram-positive rods Gram-positive - **[Non-typhoidal Salmonella](https://durgical.com/en/microbiology/non-typhoidal-salmonella/)** Enterobacterales Gram-negative - Contact - **[Non-venereal treponemes (yaws, bejel and pinta)](https://durgical.com/en/microbiology/non-venereal-treponemes/)** Other clinically important bacteria Does not Gram-stain - **[Norovirus](https://durgical.com/en/microbiology/norovirus/)** Other RNA viruses Non-enveloped (naked) - Contact - **[Onchocerca volvulus](https://durgical.com/en/microbiology/onchocerca-volvulus/)** Nematodes - **[Orientia tsutsugamushi](https://durgical.com/en/microbiology/orientia-tsutsugamushi/)** Intracellular and atypical bacteria Gram-negative - **[Oropouche virus](https://durgical.com/en/microbiology/oropouche-virus/)** RNA arboviruses Enveloped - **[Paracoccidioides brasiliensis](https://durgical.com/en/microbiology/paracoccidioides-brasiliensis/)** Dimorphic fungi - **[Paragonimus spp.](https://durgical.com/en/microbiology/paragonimus-spp/)** Trematodes (flukes) - **[Parainfluenza virus](https://durgical.com/en/microbiology/parainfluenza-virus/)** Other viruses and prions Enveloped - Contact - **[Parvovirus B19](https://durgical.com/en/microbiology/parvovirus-b19/)** Other DNA viruses Non-enveloped (naked) - Droplet - **[Pasteurella multocida](https://durgical.com/en/microbiology/pasteurella-multocida/)** Other clinically important bacteria Gram-negative - **[Pediculus humanus and Pthirus pubis](https://durgical.com/en/microbiology/pediculus-humanus-and-pthirus-pubis/)** Ectoparasites Contact - **[Plasmodium falciparum](https://durgical.com/en/microbiology/plasmodium-falciparum/)** Apicomplexans - **[Plasmodium malariae and Plasmodium ovale](https://durgical.com/en/microbiology/plasmodium-malariae-and-plasmodium-ovale/)** Apicomplexans - **[Plasmodium vivax](https://durgical.com/en/microbiology/plasmodium-vivax/)** Apicomplexans - **[Pneumocystis jirovecii](https://durgical.com/en/microbiology/pneumocystis-jirovecii/)** Yeasts and yeast-like fungi - **[Prions](https://durgical.com/en/microbiology/prions/)** Other viruses and prions Non-enveloped (naked) - **[Proteus mirabilis](https://durgical.com/en/microbiology/proteus-mirabilis/)** Enterobacterales Gram-negative - **[Pseudomonas aeruginosa](https://durgical.com/en/microbiology/pseudomonas-aeruginosa/)** Other Gram-negative rods Gram-negative - Contact - **[Rabies virus](https://durgical.com/en/microbiology/rabies-virus/)** Other RNA viruses Enveloped - **[Respiratory syncytial virus](https://durgical.com/en/microbiology/respiratory-syncytial-virus/)** Respiratory RNA viruses Enveloped - Contact - **[Rhinovirus](https://durgical.com/en/microbiology/rhinovirus/)** Respiratory RNA viruses Non-enveloped (naked) - Droplet - **[Rickettsia rickettsii / Rickettsia typhi](https://durgical.com/en/microbiology/rickettsia-rickettsii-rickettsia-typhi/)** Intracellular and atypical bacteria Gram-negative - **[Rotavirus](https://durgical.com/en/microbiology/rotavirus/)** Other RNA viruses Non-enveloped (naked) - Contact - **[Rubella virus](https://durgical.com/en/microbiology/rubella-virus/)** Respiratory RNA viruses Enveloped - Droplet - **[Salmonella Typhi](https://durgical.com/en/microbiology/salmonella-typhi/)** Enterobacterales Gram-negative - Contact - **[Sarcoptes scabiei](https://durgical.com/en/microbiology/sarcoptes-scabiei/)** Ectoparasites Contact - **[SARS-CoV-2](https://durgical.com/en/microbiology/sars-cov-2/)** Respiratory RNA viruses Enveloped - Contact - Airborne - **[Schistosoma mansoni / S. haematobium / S. japonicum](https://durgical.com/en/microbiology/schistosoma-mansoni-s-haematobium-s-japonicum/)** Trematodes (flukes) - **[Shigella](https://durgical.com/en/microbiology/shigella/)** Enterobacterales Gram-negative - Contact - **[Sporothrix schenckii](https://durgical.com/en/microbiology/sporothrix-schenckii/)** Dimorphic fungi - **[Staphylococcus aureus](https://durgical.com/en/microbiology/staphylococcus-aureus/)** Staphylococci Gram-positive - Contact - **[Staphylococcus epidermidis](https://durgical.com/en/microbiology/staphylococcus-epidermidis/)** Staphylococci Gram-positive - **[Staphylococcus saprophyticus](https://durgical.com/en/microbiology/staphylococcus-saprophyticus/)** Staphylococci Gram-positive - **[Streptococcus agalactiae](https://durgical.com/en/microbiology/streptococcus-agalactiae/)** Streptococci and enterococci Gram-positive - **[Streptococcus pneumoniae](https://durgical.com/en/microbiology/streptococcus-pneumoniae/)** Streptococci and enterococci Gram-positive - **[Streptococcus pyogenes](https://durgical.com/en/microbiology/streptococcus-pyogenes/)** Streptococci and enterococci Gram-positive - Droplet - Contact - **[Strongyloides stercoralis](https://durgical.com/en/microbiology/strongyloides-stercoralis/)** Nematodes - **[Taenia saginata](https://durgical.com/en/microbiology/taenia-saginata/)** Cestodes (tapeworms) - **[Taenia solium](https://durgical.com/en/microbiology/taenia-solium/)** Cestodes (tapeworms) - **[Talaromyces marneffei](https://durgical.com/en/microbiology/talaromyces-marneffei/)** Other fungi of clinical interest - **[Toxocara canis / Toxocara cati](https://durgical.com/en/microbiology/toxocara-canis-toxocara-cati/)** Nematodes - **[Toxoplasma gondii](https://durgical.com/en/microbiology/toxoplasma-gondii/)** Apicomplexans - **[Treponema pallidum](https://durgical.com/en/microbiology/treponema-pallidum/)** Spirochetes Does not Gram-stain - **[Triatomines (Rhodnius prolixus, Triatoma dimidiata)](https://durgical.com/en/microbiology/triatomines/)** Arthropod vectors - **[Trichinella spiralis](https://durgical.com/en/microbiology/trichinella-spiralis/)** Nematodes - **[Trichomonas vaginalis](https://durgical.com/en/microbiology/trichomonas-vaginalis/)** Intestinal and urogenital protozoa - **[Trichuris trichiura](https://durgical.com/en/microbiology/trichuris-trichiura/)** Nematodes - **[Tropheryma whipplei](https://durgical.com/en/microbiology/tropheryma-whipplei/)** Other clinically important bacteria Gram-positive - **[Trypanosoma brucei gambiense and T. b. rhodesiense](https://durgical.com/en/microbiology/trypanosoma-brucei-gambiense-and-t-b-rhodesiense/)** Hemoflagellates (trypanosomes and Leishmania) - **[Trypanosoma cruzi](https://durgical.com/en/microbiology/trypanosoma-cruzi/)** Hemoflagellates (trypanosomes and Leishmania) - **[Trypanosoma rangeli](https://durgical.com/en/microbiology/trypanosoma-rangeli/)** Other parasites of interest - **[Tunga penetrans](https://durgical.com/en/microbiology/tunga-penetrans/)** Ectoparasites - **[Varicella-zoster virus](https://durgical.com/en/microbiology/varicella-zoster-virus/)** Human herpesviruses Enveloped - Contact - Airborne - **[Variola virus](https://durgical.com/en/microbiology/variola-virus/)** Other DNA viruses Enveloped - Contact - Airborne - **[Vibrio cholerae](https://durgical.com/en/microbiology/vibrio-cholerae/)** Other Gram-negative rods Gram-negative - Contact - **[Vibrio vulnificus and Vibrio parahaemolyticus](https://durgical.com/en/microbiology/vibrio-vulnificus-and-vibrio-parahaemolyticus/)** Other clinically important bacteria Gram-negative - **[Viridans streptococci](https://durgical.com/en/microbiology/viridans-streptococci/)** Streptococci and enterococci Gram-positive - **[West Nile virus](https://durgical.com/en/microbiology/west-nile-virus/)** Other viruses and prions Enveloped - **[Wuchereria bancrofti / Brugia malayi](https://durgical.com/en/microbiology/wuchereria-bancrofti-brugia-malayi/)** Nematodes - **[Yellow fever virus](https://durgical.com/en/microbiology/yellow-fever-virus/)** RNA arboviruses Enveloped - **[Yersinia](https://durgical.com/en/microbiology/yersinia/)** Enterobacterales Gram-negative - Droplet - **[Zika virus](https://durgical.com/en/microbiology/zika-virus/)** RNA arboviruses Enveloped ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. **Contact** Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing. **Droplet** Surgical mask within about a metre; single room. **Airborne** N95 respirator and a negative-pressure room. Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given. Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/