Teach Cough Hygiene Everywhere/Pathogenic bacteria

Pathogenic bacteria are bacteria that cause bacterial infectious disease|infection. This article deals with human pathogenic bacteria. Although the vast majority of bacteria are harmless or beneficial, quite a few bacteria are pathogenic. One of the bacterial diseases with highest disease burden is tuberculosis, caused by the bacterium Mycobacterium tuberculosis, which kills about 2 million people a year, mostly in sub-Saharan Africa. Pathogenic bacteria contribute to other globally important diseases, such as pneumonia, which can be caused by bacteria such as Streptococcus and Pseudomonas, and foodborne illnesses, which can be caused by bacteria such as Shigella, Campylobacter and Salmonella. Pathogenic bacteria also cause infections such as tetanus, typhoid fever, diphtheria, syphilis and leprosy. Koch's postulates are criteria designed to establish a causal relationship between a causative microbe and a disease. Diseases Each pathogenic species has a characteristic spectrum of interactions with its human host (biology)|hosts. Conditionally pathogenic Conditionally pathogenic bacteria are only pathogenic under certain conditions, such as a wound that allows for entry into the blood, or a decrease in immune function. For example, Staphylococcus or Streptococcus are also part of the normal human flora and usually exist on the skin or in the nose without causing disease, but can potentially cause skin infections, pneumonia, meningitis and even overwhelming sepsis, a systemic inflammatory response producing shock, massive vasodilation and death.Fish DN Optimal antimicrobial therapy for sepsis Am J Health Syst Pharm 59 Suppl 1 S13–9 2002 February 11885408 http://www.ajhp.org/cgi/pmidlookup?view=long&pmid=11885408 Some species of bacteria, such as Pseudomonas aeruginosa, Burkholderia cenocepacia, and Mycobacterium avium complex|Mycobacterium avium, are opportunistic infection|opportunistic pathogens and cause disease mainly in people suffering from immunosuppression or cystic fibrosis. Heise E Diseases associated with immunosuppression 1568899 Environ Health Perspect 43 9–19 1982 7037390 10.2307/3429162 3429162Saiman L Microbiology of early CF lung disease Paediatr Respir Rev 5 Suppl A S367–9 2004 14980298 http://linkinghub.elsevier.com/retrieve/pii/S1526054204900656 10.1016/S1526-0542(04)90065-6 Intracellular Other organisms invariably cause disease in humans, such as obligate intracellular parasites that are able to grow and reproduce only within the cells of other organisms. Still, infections with intracellular bacteria may be asymptomatic, such as during the incubation period. An example of intracellular bacteria is Rickettsia. One species of Rickettsia causes typhus, while another causes Rocky Mountain spotted fever. Chlamydia (bacterium)|Chlamydia, another phylum of obligate intracellular parasites, contains species that can cause pneumonia, or urinary tract infection and may be involved in coronary heart disease. Belland R, Ouellette S, Gieffers J, Byrne G Chlamydia pneumoniae and atherosclerosis Cell Microbiol 6 2 117–27 2004 14706098 10.1046/j.1462-5822.2003.00352.x Mycobacterium and Brucella can exist intracellularly, though they are facultative (not obligate intracellular parasites.) By location Following is a list of bacterial infections classified by location in the body: Bacterial vaginosis is a disease of the vagina caused by an imbalance of naturally occurring bacterial flora and is often confused with yeast infection (candidiasis), or infection with Trichomonas vaginalis (trichomoniasis), which are not caused by bacteria.http://women.webmd.com/features/is-it-yeast-infection Terri Warren, RN Is It a Yeast Infection? 2010 2011-02-2310.1016/S0029-7844(01)01759-8 Ferris DG, Nyirjesy P, Sobel JD, Soper D, Pavletic A, Litaker MS 2002 March Over-the-counter antifungal drug misuse associated with patient-diagnosed vulvovaginal candidiasis Obstetrics and Gynecology 99 3 419–425 11864668 Bacterial meningitis is a bacterial inflammation of the meninges, that is, the protective membranes covering the brain and spinal cord. Bacterial pneumonia is a bacterial infection of the lungs. Urinary tract infection is almost exclusively caused by bacteria. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine.http://www.medicinenet.com/urine_infection/page4.htm Urinary Tract Infections 2010-02-04 The main causal agent is Escherichia coli. Although urine contains a variety of fluids, salts, and waste products, it does not usually have bacteria in it,http://www.med.umich.edu/1libr/aha/aha_asybac_crs.htm Adult Health Advisor 2005.4: Bacteria in Urine, No Symptoms (Asymptomatic Bacteriuria) 2007-08-25 http://web.archive.org/web/20070712060000/http://www.med.umich.edu/1libr/aha/aha_asybac_crs.htm 2007-07-12 but when bacteria get into the Urinary bladder|bladder or kidney and multiply in the urine, they may cause a UTI. Bacterial gastroenteritis is caused by pathogenic enteric bacteria. Such pathogenic enteric bacteria are generally distinguished from the usually harmless bacteria of the normal gut flora, but the distinction is often not fully clear, and Escherichia, for example, can belong to either group. Bacterial skin infections include: Impetigo is a highly contagious bacterial human skin|skin infection most common among pre-school children.NHS Impetigo It is primarily caused by Staphylococcus aureus, and sometimes by Streptococcus pyogenes.Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; & Mitchell, Richard N. (2007). Robbins Basic Pathology (8th ed.). Saunders Elsevier. pp. 843 978-1-4160-2973-1 Erysipelas is an acute streptococcus bacterial infectionthree/000036667 erysipelas of the deep epidermis with lymphatic spread. Cellulitis is a diffuse inflammationtwo/000019077 cellulitis of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters, burn (injury)|burns, insect bites, surgical wounds, intravenous drug injection or sites of intravenous catheter insertion. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body. Treatment Antibiotics See also Pathogenic bacteria#Clinical characteristics|overview list below Bacterial infections may be treated with antibiotics, which are classified as bacteriocide|bacteriocidal if they kill bacteria, or bacteriostatic if they just prevent bacterial growth. There are many types of antibiotics and each class enzyme inhibitor|inhibits a process that is different in the pathogen from that found in the host. For example, the antibiotics chloramphenicol and tetracyclin inhibit the bacterial ribosome, but not the structurally-different eukaryotic ribosome, and so exhibit selective toxicity. Yonath A, Bashan A Ribosomal crystallography: initiation, peptide bond formation, and amino acid polymerization are hampered by antibiotics Annu Rev Microbiol 58 233–51 2004 15487937 10.1146/annurev.micro.58.030603.123822 Antibiotics are used both in treating human disease and in intensive farming to promote animal growth. Both uses may be contributing to the rapid development of antibiotic resistance in bacterial populations.Khachatourians GG Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria CMAJ 159 9 1129–36 1998 November 9835883 1229782 http://www.cmaj.ca/cgi/pmidlookup?view=reprint&pmid=9835883 Infections can be prevented by antiseptic measures such as sterilizing the skin prior to piercing it with the needle of a syringe, and by proper care of indwelling catheters. Surgical and dental instruments are also Sterilization (microbiology)|sterilized to prevent infection by bacteria. Disinfectants such as bleach are used to kill bacteria or other pathogens on surfaces to prevent contamination and further reduce the risk of infection. Most bacteria in food are killed by cooking to temperatures above 73 °C (163°F). List of pathogenic bacteria by clinical characteristics This is a rather clinical description of the species presented in the previous section, containing the main examples of Transmission (medicine)|transmission, diseases, treatment, prevention and Laboratory diagnosis of bacteria|laboratory diagnosis, which all can differ substantially among the species of the same genus. +Species of human pathogenic bacteria SpeciesTransmission Diseases Treatment Prevention laboratory diagnosis Bacillus anthracis Contact with sheep, goats and horses Inhalation or skin penetration through abrasions of spore-contaminated dustCutaneous anthrax Pulmonary anthrax Gastrointestinal anthrax In early infection: Penicillin Doxycycline CiprofloxacinAnthrax vaccine autoclaving of instruments Large, grayish, nonhemolytic colonies with irregular borders on blood agar Direct immunofluorescence Bordetella pertussis Contact with respiratory droplets expelled by infected human hosts.Whooping cough Complications: Secondary bacterial pneumoniaMacrolide antibiotics Azithromycin Erythromycin ClarithromycinPertussis vaccine, DPT vaccineDirect immunofluorescence PCR amplification Borrelia burgdorferi Ixodes ticks reservoir in deer, mice and other rodentsLyme disease Early stages: cephalosporins amoxicillin doxycycline If arthritic symptoms have appeared: Longer courses of antibiotics Lyme vaccine wearing clothing that limits skin exposure to ticks insect repellent Microscopy using Giemsa stain|Giemsa or Wright stain polymerase chain reaction|PCR serology (low precision rate) Brucella abortus Brucella canis Brucella melitensis Brucella suis Direct contact with infected animal Oral, by ingestion of unpasteurized milk or milk products Brucellosis Combination therapy of: doxycycline streptomycin or gentamicin - Culture (difficult and time consuming) Agglutination (biology)|Agglutination serology Campylobacter jejuni Fecal/oral from animals (mammals and fowl) Contaminated meat (especially poultry) Contaminated water Acute enteritis Symptomatically by fluid and electrolyte replacement Ciprofloxacin in severe cases No available vaccine Good hygiene Avoiding contaminated water Pasteurizing milk and milk products Cooking meat (especially poultry) Finding campylobacter in feces Chlamydia pneumoniae Respiratory droplets Community-acquired respiratory infection Doxycycline Erythromycin None None for routine use Chlamydia trachomatis Sexual (Lymphogranuloma venereum|NGU, lymphogranuloma venereum|LGV) Direct or contaminated surfaces and flies (trachoma) Passage through birth canal (Inclusion conjunctivitis of the newborn|ICN)Nongonococcal urethritis (NGU) Lymphogranuloma venereum (LGV) Trachoma Inclusion conjunctivitis of the newborn (ICN) Azithromycin Erythromycin Tetracyclines Doxycycline No vaccine Erythromycin or silver nitrate in newborn's eyes Safe sex Cellular cytoplasmic inclusions by immunofluorescence DNA hybridization ELISA for lipopolysaccharides Chlamydophila psittaci Inhalation of dust with secretions or feces from birds (e.g. parrots) Psittacosis Tetracycline Doxycycline Erythromycin (less efficient) - Rise in antibody titre Complement fixation indirect immunofluorescence Clostridium botulinum Spores from soil and aquatic sediments contaminating vegetables, meat and fishBotulism Antitoxin (horse antiserum) Proper food preservation techniques Mouse inoculation detects toxin from food, intestinal contents or serum Culture in standard aerobic culture Clostridium difficile Spores both indoors and outdoors Human flora, overgrowing when other flora is depletedPseudomembranous colitis Discontinuing predisposing antibiotic Fluid and electrolyte replacement Vancomycin or metronidazole if severe NoneELISA for Clostridium_difficile#Toxin ELISA|Toxin ELISA for toxin A or B Endoscopy for pseudomembrane Clostridium perfringens Spores in soil Human flora in vagina and GI tract Gas gangrene Acute food poisoning Anaerobic cellulitis Gas gangrene: Debridement or amputation Hyperbaric medicine High doses of penicillin G or doxycycline Food poisoning: Self-limiting; Supportive care is sufficient Appropriate food handling Microscopically Blood agar culture, forming double-zone beta hemolysis|β-hemolysis Sugar fermentation Organic acid production Clostridium tetani Spores in soil infecting puncture wounds, severe burns or surgeryTetanus Tetanus immune globulin Horse antitoxin, alternatively Sedatives Muscle relaxants Mechanical ventilation DPT vaccine (difficult) Corynebacterium diphtheriaeRespiratory droplets Part of human floraDiphtheria Horse serum antitoxin Erythromycin PenicillinDPT vaccine (no rapid) Culture on Tinsdale agar, followed by immunologic precipitin reaction Enterococcus faecalis and Enterococcus faecium Part of human flora, Opportunistic infection|opportunistic or entering through GI tract or urinary system wounds Nosocomial infections Penicillin and an aminoglycoside Vancomycin Quinupristin and dalfopristin No vaccine Hand washing and other Nosocomial#Prevention|nosocomial preventionCulture in 6.5% Sodium chloride|NaCl Can hydrolyze esculin in presence of bile Escherichia coli (generally) Part of gut flora, spreading extraintestinally or proliferating in the GI tract Urinary tract infections (UTI) Diarrhea Meningitis in infants UTI: (resistance-tests are required first) Co-trimoxazole Fluoroquinolone, e.g. ciprofloxacin Meningitis: Cephalosporin (e.g. cefotaxime) and gentamicin combination Diarrhea: Antibiotics above shorten duration Electrolyte and fluid replacement (no vaccine or preventive drug) Food and water preparation Cooking ground beef and pasteurizing milk against O157:H7 Hand washing and disinfection Culture on MacConkey agar and study carbohydrate fermentation patterns: Lactose fermentation (most E. coli strains) Gas production in glucose fermentation Mannitol fermentationEnterotoxigenic Escherichia coli (ETEC) Fecal-oral through food and water Direct physical contactTraveller's diarrheaEnteropathogenic E. coli Transmission_(medicine)#Vertical_Transmission|Vertical, in utero or at birthDiarrhea in infantsE. coli O157:H7 Reservoir in cattle Hemorrhagic colitis Hemolytic-uremic syndrome Francisella tularensis Vector (epidemiology)|vector-borne by arthropods Infected wild or domestic animals, birds or house petsTularemiaStreptomycin GentamicinAvoiding insect vectors Precautions when handling wild animals or animal products (rarely cultured) Serology Haemophilus influenzae Droplet contact Human flora of e.g. upper respiratory tractBacterial meningitis Upper respiratory tract infections Pneumonia, bronchitis Meningitis: (resistance-tests are required first) Cephalosporin#Third_generation|Third generation cephalosporin, e.g. cefotaxime or ceftriaxone Ampicillin and sulbactam combinationHib vaccine to infants Rifampin prophylacticallyCulture on chocolate agar with hemin (factor X) and Nicotinamide adenine dinucleotide|NAD+ (factor V) Quellung reaction Immunofluorescence staining of capsule Detection of capsular antigen in Cerebrospinal fluid|CSF or other body fluids Helicobacter pylori Colonizing stomach Unclear person-to-person transmissionPeptic ulcer Risk factor for gastric carcinoma and gastric B-cell lymphomaTetracycline, metronidazole and bismuth salt combination (No vaccine or preventive drug) Microscopically Corkscrew movement Urease-positivity by radioactively labeled urea Serology by ELISA Legionella pneumophila Droplet contact, from e.g. cooling towers, humidifiers, air conditioners and water distribution systemsLegionnaire's Disease Pontiac fever Macrolides, e.g. erythromycin or azithromycin Fluoroquinolones (no vaccine or preventive drug) Heating water Culture from respiratory secretions on buffered charcoal yeast extract enriched with L-cysteine, iron and Alpha-ketoglutaric acid|α-ketoglutarate Serology, including direct immunofluorescence and radioimmunoassay for antigen in urine Hybridization to ribosomal RNA using DNA probe Leptospira interrogans Food and water contaminated by e.g. urine from wild or domestic animals. Leptospira survives for weeks in stagnant water.LeptospirosisPenicillin G Tetracycline, e.g. doxycycline (no vaccine) Doxycycline Prevention of exposure Rodent controlDark-field microscopy on fresh blood smear (but doesn't stain well) Serologic agglutionation tests Listeria monocytogenes Dairy products, ground meats, poultry Transmission_(medicine)#Vertical_Transmission|Vertical to newborn or fetusListeriosis Ampicillin Co-trimoxazole (no vaccine) Proper food preparation and handlingCSF Beta-hemolysis and catalase production on blood agar Microscopy for morphology and motility Mycobacterium leprae Prolonged human-human contact, e.g. through exudates from skin lesions to abrasion of other personLeprosy (Hansen's disease) Tuberculoid form: Dapsone and rifampin Lepromatous form: Clofazimine Bacillus Calmette-Guérin|BCG vaccine shows some effects Tuberculoid form: Hard to isolate (diagnosis on clinical findings and histology of biopsies) Lepromatous form: Acid-fast staining from e.g. skin scrapings Mycobacterium tuberculosis Droplet contactTuberculosis (difficult, see Tuberculosis treatment for more details) Standard "short" course: First 2 months, combination: Isoniazid Rifampicin Pyrazinamide Ethambutol Further 4 months, combination: Isoniazid RifampicinBacillus Calmette-Guérin|BCG vaccine IsoniazidZiehl-Neelsen stain showing acid-fast bacteria Hybridization probes for DNA, succeeded by Polymerase chain reaction|PCR Culture on Lowenstein-Jensen agar Mycoplasma pneumoniae Human flora Droplet contactMycoplasma pneumoniaDoxycycline and erythromycin (difficult to culture) Serologic tests, e.g. complement fixation test DNA probes on sputum specimens Neisseria gonorrhoeae Sexually transmitted disease|Sexually transmitted Vertical transmission|vertical in birthGonorrhea Ophthalmia neonatorum Septic arthritis Uncomplicated gonorrhea: Ceftriaxone Tetracycline, e.g. doxycycline if also chlamydia is suspected Spectinomycin for resistance or patient allergy to cephalosporin Ophthalmia neonatorum: Tetracycline or erythromycin into eyes (No vaccine) Safe sex Tetracycline or erythromycin into eyes of newborn at riskGram-negative bacteria|Gram-negative diplococci in neutrophils from urethral exudates Oxidase test on culture on Thayer-Martin agar under increased oxygen tension Fermentation of glucose but not maltose Neisseria meningitidisRespiratory dropletsMeningococcal disease including meningitis Waterhouse-Friderichsen syndromePenicillin G Cefotaxime CeftriaxoneNmVac4-A/C/Y/W-135 vaccine Rifampin Microscopy showing gram-negative diplococci, often with polymorphonuclear leukocytes|PMNs Culture on chocolate agar, giving positive oxidase test and fermentation of glucose and maltose in 5% CO2 in air Pseudomonas aeruginosa Infects damaged tissues or people with reduced immunity. Pseudomonas infection Localized to eye, ear, skin, urinary, respiratory or gastrointestinal tract or CNS, or systemic with bacteremia, secondary pneumonia bone and joint infections, endocarditis, skin, soft tissue or CNS infections.Aminoglycoside and anti-pseudomonal beta-lactam|β-lactam (no vaccine) Topical silver sulfadiazine for burn woundsColourless colonies on MacConkey agar. Production of pyocyanine and fluorescein Positive oxidase test. No lactose fermentation. Rickettsia rickettsii Bite of infected Dermacentor variabilis|wood or Rhipicephalus sanguineus|dog tickRocky mountain spotted feverDoxycycline Chloramphenicol (no preventive drug or approved vaccine) Vector control, such as clothing Prompt removal of attached ticks Serology Immunofluorescence against Rickettsia antigens Salmonella typhi Human-human Fecal-oral through food or waterTyphoid fever type salmonellosis (dysentery, colitis)Ceftriaxone Fluoroquinolones, e.g. ciprofloxacinTy21a and Vi capsular polysaccharide vaccine|ViCPS vaccines Hygiene and food preparationIsolation from blood, feces, bone marrow, urine or rose spots on skin Colorless, non-lactose fermenting colonies on MacConkey agar Serology for antibodies against O antigen Salmonella typhimurium Fecal-oral Food contaminated by fowl (e.g. eggs), pets and other animals Salmonellosis with gastroenteritis and enterocolitisFluid and electrolyte replacement for severe diarrhea Antibiotics (in immunocompromised to prevent systemic spread) (No vaccine or preventive drug) Proper sewage disposal Food preparation Good personal hygieneColourless colonies on MacConkey agar Shigella sonnei Fecal-oral Flies Contaminated food or waterShigellosis|Bacillary dysentery/ShigellosisCiprofloxacin or azithromycinProtection of water and food supplies Vaccines are in trial stageInstitut Pasteur Press Office - Vaccine against shigellosis (bacillary dysentery):a promising clinical trial 15 January 2009. Retrieved on 27 February 2009 Culture on Hektoen agar or other media for intestinal pathogens Staphylococcus aureus Human flora on Mucous membrane|mucosae in e.g. anterior nares and vagina, entering through wound Coagulase-positive staphylococcal infections: Localized skin infections Diffuse skin infection (Impetigo) Deep, localized infections Infective_endocarditis#Classification|Acute infective endocarditis Septicemia Necrotizing pneumonia Toxinoses Toxic shock syndrome Staphylococcal food poisoningIncision and drainage of localized lesions Nafcillin and oxacillin Vancomycin for Methicillin-resistant Staphylococcus aureus|Methicillin-resistant (MRSA) (no vaccine or preventive drug) Barrier precautions, washing hands and fomite disinfection in hospitalsMicroscopy showing strongly positive Gram staining|Gram stained cells in grape-like clusters Positive Catalase#Catalase_test|Catalase test and coagulase test Culture on enriched media producing deep yellow, hemolytic colonies Staphylococcus epidermidis Human flora in skin and anterior nares Infections of implanted Prosthesis|prostheses, e.g. heart valves and cathetersVancomycin NoneMicroscopy showing strongly positive Gram staining|Gram stained cells in grape-like clusters Positive Catalase#Catalase_test|Catalase test but negative coagulase test Novobiocin-sensitivity (S. epidermidis) Novobiocin-resistance (S. saprophyticus) Culture on enriched media producing white, nonhemolytic colonies Staphylococcus saprophyticus Part of normal vaginal flora Cystitis in women Penicillin G None Streptococcus agalactiae Human flora in vagina or urethral mucous membranes, rectum Vertical transmission by birth Sexually transmitted disease|SexualMeningitis and septicemia in neonates Endometritis in postpartum women Opportunistic infections with septicemia and pneumoniaPenicillin G Ampicillin Aminoglycoside in case of lethal infection NoneCulture showing large colonies with Hemolysis_(microbiology)#Beta|β-hemolysis Negative catalase test Hydrolyzes sodium hippurate Streptococcus pneumoniae Respiratory droplets Often human flora in nasopharynx (spreading in immunocompromised)Acute bacterial pneumonia & meningitis in adults Otitis media and sinusitis in childrenPenicillin G Vancomycin for resistant strains23-serotype vaccine for adults (Pneumococcal polysaccharide vaccine|PPV) Heptavalent conjugated vaccine for children (Pneumococcal conjugate vaccine|PCV)Microscopy showing gram-positive, encapsulated lancet-shaped diplococci Hemolysis_(microbiology)#Alpha|α-hemolysis on blood agar, bile-soluble, optochin-sensitive Positive Quellung reaction Streptococcus pyogenesRespiratory droplets Direct physical contact with impetigo lesions Streptococcal pharyngitis Scarlet fever Rheumatic fever Impetigo and erysipelas Puerperal fever Necrotizing fasciitisPenicillin G Macrolide, e.g. clarithromycin or azithromycin in penicillin allergy Drainage and debridement for Necrotizing fasciitis No vaccine Rapid antibiotic treatment helps prevent rheumatic feverCulture on sheep blood agar forming small, Opalescence|opalescent surrounded by large zone of Hemolysis_(microbiology)#Beta|β-hemolysis Serology for Anti-streptolysin O|ASO Very bacitracin-sensitive Treponema pallidum SexualSyphilis Congenital syphilis Penicillin G Erythromycin or tetracycline if penicillin allergy No preventive drug or vaccine Safe sex Antibiotics to pregnant women at risk of transmitting congenital syphilis Cannot be cultured or viewed in gram-stained smear Dark field microscopy Serology, including nontreponemal (Venereal Disease Research Laboratory test|VDRL, Rapid plasma reagin|RPR) and treponemal tests (FTA-ABS, TPI test|TPI, Syphilis TPHA test|TPHA) Vibrio cholerae Contaminated water and food, especially raw seafoodCholeraFluid and electrolyte replacement e.g. doxycycline to shorten durationPreventing fecal contamination of water supplies and food Adequate food preparationCulture on blood agar|blood or MacConkey agar, enhanced by Thiosulfate citrate bile sucrose|TCBS Positive oxidase test Yersinia pestisFleas from animals Ingestion of animal tissues Respiratory dropletsPlague: Bubonic plague Pneumonic plagueStreptomycin primarily Gentamicin Tetracyclin Supportive therapy for Shock (circulatory)|shockFormalin-killed plague vaccine Minimize exposure to rodents and fleasGram-negative smear If pneumonic, culture from aspirate on MacConkey agar|MacConkey or blood agar