Microbiology & Parasitology PDF

MICROBIOLOGY & PARASITOLOGY To God be the Greatest Glory! MEDICAL BACTERIOLOGY GRAM-POSITIVE COCCI GRAM-STAIN OTHER FEATURES ORGANISM Catalase-positive ENCAPSULATED BACTERIA...

MICROBIOLOGY & PARASITOLOGY To God be the Greatest Glory! MEDICAL BACTERIOLOGY GRAM-POSITIVE COCCI GRAM-STAIN OTHER FEATURES ORGANISM Catalase-positive ENCAPSULATED BACTERIA Staphyloccus aureus - capsules serve as an antiphagocytic virulence factor Coagulase-positive Catalase-positive - are opsonized, and then cleared by spleen Gram Positive Cocci Coagulase-negative Staphyloccus epidermidis - Asplenics have Ü opsonizing ability and thus Û risk for severe infections - Give S. pneumoniae, H. influenzae, N. meningitidis vaccines in Clusters Novobiocin-sensitive Catalase-positive Some Killers Have Pretty Nice, Elegant, Shiny Bodies Coagulase-negative Staphyloccus saprophyticus Novobiocin-resistant Streptococcus pneumoniae Klebsiella pneumoniae GRAM-STAIN OTHER FEATURES ORGANISM Haemophilus Influenzae type B Catalase-negative Pseudomonas aeruginosa Alpha-hemolytic Streptococcus pneumoniae Neisseria meningitidis Bile-optochin-sensitive Escherichia coli Catalase-negative Salmonella typhi Alpha-hemolytic Viridans streptococci Group B Strep Bile-optochin-resistant Gram Positive Cocci Catalase-negative Streptococcus pyogenes in Chains Beta-hemolytic (Group A Beta Hemolytic Streptococcus Bacitracin-sensitive / GABHS) CATALASE-POSITIVE ORGANISMS Catalase-negative - Catalase degrades H2O2 into H2O and bubbles of O2 before it can be Streptococcus agalactiae converted to microbicidal products by the enzyme myeloperoxidase Beta-hemolytic (Group B Streptococcus / GBS) Bacitracin-resistant - People with chronic granulomatous disease (NADPH oxidase deficiency) Catalase-negative have recurrent infections with certain catalase-positive organisms Group D Streptoccocci Gamma-hemolytic PLACES NBSH Pseudomonas GRAM-POSITIVE BACILLI Listeria GRAM-STAIN O2 UTILIZATION OTHER FEATURES ORGANISM Aspergillus Non-motile Candida Box-car-shaped Bacillus anthracis Aerobic Medusa head E. coli Motile Staphylococci Bacillus cereus Nocardia Reheated Fried Rice Spore-forming Drumstick-, tennis B. cepacia gram-positive racket-, or lollipop- Clostridium tetani Serratia rods like H. pylori Bulging cans Clostridium botulinum Anaerobic Lecithinase Double hemolysis Clostridium perfringens PIGMENT-PRODUCING BACTERIA Gas-forming Actinomyces israelii Yellow “sulfur” granules Pseudomembranes Clostridium difficile Staphylococcus aureus Yellow pigment Non-motile Non-Spore- Corynebacterium Pseudomonas aeruginosa Blue-green pigment Curved diphtheria (pyocyanin and pyoverdin) forming gram- Aerobic Chinese characters Curved Serratia marcescens Red pigment positive rods Listeria monocytogenes Tumbling Motility  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Staphylococcus Human nose Direct contact (Hands) Catalase-positive IMMUNOMODULATORS: Exofoliatin: causes PYOGENIC: Methicillin-sensitive GRAM-STAIN: 95% resistance to aureus (anterior nares) To test, rub a wire Protein A: prevents epidermal separation SKIN and SOFT TISSUE INFECTIONS SA (MSSA) reveals gram-positive penicillins and skin Fomites loop across a colony complement activation; in Scalded Skin î bullous impetigo, folliculitis, furuncles, î Penicillinase- cocci in grape-like of gram-positive binds IgG, preventing Syndrome carbuncles, cellulitis, hidradenitis resistant cluster 60% MRSA in the Contaminated food cocci and mix on a opsonization and suppurativa, mastitis, surgical site penicillins Philippines slide with H202. If phagocytosis infections CULTURE: Enterotoxins (heat- (nafcillin, oxacillin, bubbles appear, - Beta-hemolytic Community acquired stable): superantigens ACUTE ENDOCARDITIS and dicloxacillin) this indicates that Coagulase: Allows insoluble causing food - Produces a golden methicillin resistant H202 is being broken î most common cause of acute fibrin formation around poisoning Methicillin-resistant yellow colonies on Staphylococcus down into oxygen endocarditis organism, protecting it SA (MRSA) blood agar aureus (CA-MRSA) bubbles and water; î native valve (tricuspid valve) in IV catalase-positive from phagocytosis Toxic shock î contain altered - “Gold color” is due produces a particular drug abusers staphylococci are syndrome toxin penicillin-binding to pigment leukocidin called Hemolysins (cytotoxins): present. (TSST-1): superantigen PNEUMONIA protein (PRB) STAPHYLOXANTHIN Panton-Valentine toxic to hematopoietic cells î nosocomial pneumonia, VAP, î due to resistance Leukocidin leading to toxic shock Coagulase-positive necrotizing pneumonia gene mecA Polymerase chain (PVL), which is syndrome Leukocidin: specific for î complicated by empyema, abscess or î DOC is reaction (PCR): mecA associated with a Salt-tolerant on WBCs pneumatocele vancomycin gene for MRSA propensity to form Alpha toxin: causes Mannitol salt agar î post-viral pneumonia abscesses marked necrosis of the (halotorelant) Catalase: detoxifies Vancomycin- skin and hemolysis OSTEOMYELITIS and SEPTIC ARTHRITIS hydrogen peroxide resistant SA (VRSA) î from hematogenous spread or local Facultative anaerobe introduction at wound site î DOC is linezolid Penicillinase: secreted form î Brodie Abscess: sequestered focus of Causes of of beta-lactamase; disrupts osteomyelitis arising in the Necrotizing the beta-lactam portion of metaphyseal area of a long bone Pneumonia the penicillin molecule, thereby inactivating the TOXIGENIC: î S. aureus antibiotic GASTROENTERITIS î Pseudomonas î acute onset (4 hrs) of vomiting and î Aspergillus TISSUE PENETRANCE: diarrhea due to ingestion of preformed î Viral Pneumonia Hyaluronidase: "Spreading heat-stable enterotoxin Factor"; breaks down î source: salad made with mayonnaise proteoglycans in connective (potato or tuna salad) tissue (hyaluronic acid) SCALDED SKIN SYNDROME (Ritter Fibrinolysin Disease) (Staphylokinase): dissolves î exfoliatin cleaves desmoglein in fibrin clots desmosomes î separation of skin at stratum Lipase: spread in fat- granulosum (vs TENS/Lyell disease: containing areas of the separation occurs at dermo-epidermal body junction) TOXIC SHOCK SYNDROME Protease: destroys tissue î fever, hypotension, sloughing of proteins filiform papillaeàstrawberry tongue, desquamating rash and multi-organ involvement (>3) î usually no site of pyogenic inflammation; blood CS negative î tampon-using menstruating women or in patients with nasal packing for epistaxis  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Staphylococcus Humans (normal Autoinfection Catalase-positive Polysaccharide capsule: Most common cause of: Vancomycin (50% GRAM STAIN: NOVOBIOCIN epidermidis skin flora) Direct contact (hands) adheres to a variety of - prosthetic valve endocarditis methicillin gram-positive cocci in Coagulase-negative Sensitive prosthetic devices; forms a - septic arthritis in prosthetic joints resistance) clusters biofilm - ventriculoperitoneal shunt Epidermidis Facultative anaerobe infections Removal of CULTURE: Resistant Novobiocin-sensitive Highly resistant to prosthetic device White colonies on Saprophyticus (Novo SERS) antibiotics blood agar, non- hemolytic Staphylococcus Humans Catalase-positive UTI IN WOMEN Fluoroquinolones GRAM STAIN: nd saphrophyticus Coagulase-negative î S. saprophyticus is the 2 most gram-positive cocci in Facultative anaerobe common cause of UTI in sexually TMP-SMX clusters active women [ Nitrite-negative CULTURE: (unlike E. coli) Whitish, non- Novobiocin-resistant hemolytic on blood (Novo SERS) agar Streptococcus Humans Respiratory droplets Catalase-negative Hyaluronidase: degrades Erythrogenic toxin: PYOGENIC: DOC is Penicillin G GRAM STAIN: Disease of poverty pyogenes hyaluronic acid (spreading produces scarlet fever IMPETIGO CONTAGIOSA: perioral Gram-positive cocci in Bacitracin-sensitive factor) blisters with honey-colored crust; Patients with a chains The antigenic (B-BRAS) Streptolysin O accumulation of neutrophils beyond the history of rheumatic components of the Group A Beta- Beta-hemolytic Bacitracin Streptokinase (fibrinolysin) (oxygen-labile): highly stratum corneum; complication includes fever require long- streptococcal cell Hemolytic Group B Strep *Anti-streptokinase antigenic, causes AB PSAGN term antibiotic wall: Lancefield group A Streptococcus Resistant antibodies decrease efficiency formation; destroys prophylaxis to - C carbohydrate: ERYSIPELAS: superficial infection (GABHS) Group A Strep of streptokinase in managing RBCs and WBCs; and is prevent recurrence Positive PYR test for Lancefield Sensitive MI extending into dermal lymphatics the reason for the of the disease PYR test measures typing beta hemolysis CELLULITIS: deeper infection involving hydrolysis of 1- - M protein (80 DNase (streptodornase): *ASO Titers to subcutaneous/dermal tissues; facilitated pyrrolidonyl-B- naphthylamide and types): a major degrades DNA in exudates document antecedent by hyaluronidase (spreading factor) or necrotic tissue release of B- virulence factor PHARYNGITIS PHARYNGITIS: most common bacterial *Anti-DNAse B to document naphthylamine, which in for the group A cause of sore throat the presence of p- streptococcus; antecedent SKIN infection Streptolysin S (oxygen-stable): not TOXIGENIC: dimethylaminocinnamal inhibits the C5a peptidase: inactivates SCARLET FEVER: “second disease”; dehyde forms a red activation of antigenic complement C5a compound complement and post-pharyngitic; due to erythrogenic Advantage: takes 38C, CAMP test–positive: CAUSES OF broth PROM (>18h), vaginal colonization, and All pregnant women CAMP factor enlarges NEONATAL complement deficiency should be screened the area of hemolysis MENINGITIS: Hydrolyzes hippurate for GBS colonization formed by S. aureus î GBS ENDOMETRITIS → most commonly at 35-37 wks AOG; if î Escherichia coli polymicrobial; foul-smelling lochia (+), chemo- Lancefield group B î Listeria prophylaxis with IV monocytogenes penicillin or Ampicillin 4h prior to delivery Group D Human colon May enter Catalase-negative UTIs due to indwelling urinary catheters Penicillin plus Gram-positive cocci in There is a remarkable streptococci bloodstream during and urinary tract instrumentation gentamicin chains association between GIT or GUT surgery Bile and optochin- S. bovis infection Urethra and female resistant BILIARY TRACT INFECTIONS Vancomycin for Gamma hemolytic and colon cancer genital tract can be penicillin-resistance colonies colonized Hydrolyzes esculin in ENDOCARDITIS in patients who bile esculin agar underwent GIT surgery due to Linezolid for Lancefield group D (BEA) Enterococcus faecalis vancomycin- resistant strains Positive PYR test E. faecalis can grow MARANTIC ENDOCARDITIS in patients in 6.5% NaCl while S. with abdominal malignancy due to bovis cannot Streptococcus bovis Streptococcus Upper respiratory Respiratory droplets Catalase-negative Polysaccharide Capsule: PNEUMONIA: most common cause of Penicillin G Gram-positive Polyvalent (23-type) pneumoniae / tract retards phagocytosis; major CAP in adults; rust-colored sputum "lancet-shaped" cocci polysaccharide Pneumococcus Bile and optochin- virulence factor; has 84 Levofloxacin or in pairs or chains vaccine sensitive OTITIS MEDIA: most common cause in Vancomycin serotypes; antigenic Alpha-hemolytic OVRPS (overpass) children combined with Conjugated vaccine: *Optochin sensitivity IgA protease: for BACTERIAL MENINGITIS: most common Ceftriaxone for Positive Quellung pneumococcal differentiates Strep colonization cause in adults penicillin resistance reaction: capsular polysaccharide pneumoniae from swelling when mixed with a coupled with carrier Viridans strep (since SINUSITIS small amount of antiserum protein (diphtheria c-substance: reacts with both are alpha (serum with antibodies to toxoid) CRP SEPTIC SHOCK: splenectomy predisposes the capsular antigens) hemolytic) to sepsis from encapsulated bacteria and methylene blue No Lancefield antigen Viridans Oral flora Enters bloodstream Catalase-negative Glycocalyx enhances DENTAL CARIES: S. mutans Penicillin G +/- Gram-positive cocci in OVeRPaSs Streptococci during dental adhesion to damaged aminoglycoside chains Bile and optochin- SUBACUTE BACTERIAL ENDOCARDITIS OPTOCHIN procedures heart valves (Gentamicin) resistant (SBE): S. sanguis à most common cause Alpha-hemolytic Viridans OVRPS (overpass) Vancomycin for Protected from host of subacute and native valve Resistant Viridans strep live in the endocarditis penicillin-resistance mouth because they are defenses within Pneumoniae vegetations Linezolid for not afraid of the chin BRAIN ABSCESSES: S. intermedius Sensitive (op-to-chin resistant) vancomycin- resistant strains  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Bacillus anthracis Herbivores Contact with infected Aerobic (but since it Protein capsule: polymer of Exotoxin (encoded on CUTANEOUS ANTHRAX: Cutaneous Anthrax: Aerobic, gram-positive Bacillus anthracis is (zoonotic): animals or inhalation can grow without gamma-D-glutamic acid; plasmin pXO1) - Most common route of entry (95%) DOC is ciprofloxacin box-car shaped rods; the only bacterium - Sheep of spores from animal oxygen. It is classified antiphagocytic; encoded contains 3 separate - Direct epidermal contact with spores spore-forming; NON- with a capsule - Goats hair or wool as a facultative on a plasmid called pXO2 proteins, which by causes localized tissue necrosis, Inhalational / MOTILE composed of protein - Cattle (woolsorter’s disease) anaerobe) themselves are evidenced by a painless round black Gastrointestinal (poly-D-glutamic nontoxic but lesion with a rim of edema Anthrax: Medusa head acid). Habitat is soil Human-to-human Virulence depends on together produce the (malignant pustule) Ciprofloxacin or morphology on transmission has never acquiring 2 plasmids. One systemic effects of - 20% mortality rate Doxycycline with 1 culture: dry “ground Infections result to been reported. carries the gene for the anthrax: INHALATIONAL/PULMONARY ANTHRAX: or 2 additional glass” surface and permanent immunity protein capsule (pXO2); the - Edema factor (EF): - inhaled spores from animals antibiotics irregular with (if the patient other carries the gene for its the active A subunit (Woolsorter’s disease) or from (Rifampin, projections along lines survives) exotoxin (pXO1) of the exotoxin; weaponized preparations Vancomycin, of inoculation calmodulin- (bioterrorism) Penicillin, RAXIBACUMAB: dependent - prolonged latent period (2mos) Imipenem, Serology monoclonal antibody adenylate cyclase before rapid deterioration Clindamycin, for use in inhalational - Protective antigen - massively enlarged mediastinal Clarithromycin) PCR of nasal swab anthrax (PA): promotes entry of EF into lymph nodes; pulmonary hemorrhage (MCC of death); Vaccine: for high- Cutaneous Anthrax phagocytic cells meningeal symptoms risk individuals; - Lethal factor (LF): - 100% mortality rate without composed of the zinc metallo- MCC of death is immediate treatment protective antigen protease that pulmonary (PA); Animal inactivates protein GASTROINTESTINAL ANTHRAX: hemorrhage in: vaccine is kinase; stimulates - ingestion of live spores leads to UGI - Anthrax composed of a live the macrophage to ulceration, edema, and sepsis - Leptospirosis strain, attenuated release TNF-a and - vomiting abdominal pain, bloody (Weil’s syndrome) by loss of its IL-1B à death diarrhea protein capsule - Congenital syphilis PA + EF = Edema Toxin - rapidly progressive course PA + LF = Lethal Toxin - mortality approaches 100% Bacillus cereus Endospores No capsule ENTEROTOXINS EMETIC FORM DIARRHEAL FORM Food Poisoning: Aerobic, gram-positive Heat-labile: similar to Rice Meat, vegetables Symptomatic spore-forming rod; Spores on grains such the enterotoxin of Short IP: 6 hrs treatment only; MOTILE as rice survive cholera and the LT (mean, 2h) (mean, 9h) food poisoning steaming and rapid from E. coli; causes Vomiting, nausea, Diarrhea, nausea, is caused by the Culture specimen from frying ADP-ribosylation, abdominal cramps abdominal cramps pre-formed suspected food source increasing cAMP enterotoxin Shorter duration: Longer duration: Spores germinate 8-10h (mean, 9) 20-36h (mean, 24) when rice is kept Heat-stable: Ophthalmitis: Heat-stable Heat-labile warm for many hours staphylococcal-like Vancomycin enterotoxin enterotoxin (e.g., reheated fried enterotoxin functions Clindamycin Similar to Resembles rice) à Chinese fried as superantigen Ciprofloxacin staphylococcal clostridial rice syndrome Gentamicin food poisoning gastroenteritis Resistant to beta- OPHTHALMITIS: occur after penetrating lactam antibiotics eye injuries of the eye with soil- contaminated object; complete loss of light perception within 48 h of injury  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Clostridium tetani Habitat is soil Endospores: Spores germinate Motile: Flagella (so H- Tetanus Toxin TETANUS Debridement of Anaerobic, gram- Obligate Anaerobes introduced through under anaerobic antigen-positive) (Tetanospasmin) - “the acute onset of hypertonia or … primary wound positive, spore-forming Can’t Breathe Fresh Air wound or traumatic conditions in the painful muscular contractions (usually rods, often with an Clostridium break in the skin wound Tetany occurs after the of the muscles of the jaw and neck) Metronidazole endospore at one end tetanus toxin is taken up and generalized muscle spasms or Penicillin (see Bacteroides - Skin popping in IV (terminal spore), giving drug use at the neuromuscular without other apparent medical notes) them the appearance Fusobacterium junction (end plate) and cause” --CDC - Stepping on a nail is transported to the of a drumstick, tennis Actinomyces - strong muscle spasm Tetanus toxoid: central nervous system racket, or lollipop - lockjaw (trismus) vaccination with (retrograde transport). - risus sardonicus formalin- There the toxin acts on the TETANUS PROPHYLAXIS inhibitory Renshaw cell - opisthotonos inactivated toxin interneurons, preventing - respiratory muscle paralysis (toxoid), part of the VACCINATION HISTORY Metronidazole (400 the release of GABA and DPT vaccine; given Uncertain or 3 doses mg rectally or 500 mg WOUND glycine, which are in childhood and IV every 6 h for 7 days) Toxoid Toxoid inhibitory NEONATAL TETANUS is defined by the q10yrs thereafter TIG (ATS) TIG (ATS) is the preferred (TeANA) (TeANA) neurotransmitters. This World Health Organization (WHO) as “an inhibition of inhibitory antibiotic. An NO (Yes, only illness occurring in a child who has the Antitoxin (ATS): interneurons allows motor alternative is penicillin Clean, minor YES NO if last dose NO normal ability to suck and cry in the first 2 human tetanus (100,000–200,000 neurons to send a high Requires anaerobic given >10y) days of life but who loses this ability immune globulin IU/kg per day), frequency of impulses to conditions NO (Yes, only muscle cells, which results between days 3 and 28 of life and becomes (TIG) at the wound although this drug Contaminated YES YES if last dose NO in a sustained tetanic rigid and has spasms.” site à Passive theoretically may given >5y) contraction. exacerbate spasms. Supportive therapy: (Harrisons) may require ventilator assistance Clostridium Habitat is soil Endospores (heat Anaerobic Motile: Flagella (so H- Botulinum toxin: FOOD-BORNE BOTULISM: eye symptoms Trivalent Botulinum Anaerobic, gram- TRIAD OF BOTULISM: botulinum resistant) antigen-positive) - heat-labile (BOV, diplopia, ptosis, mydriasis), bulbar Antitoxin (for food- positive, spore-forming - Symmetric Alkaline neurotoxin signs (diplopia, dysphonia, dysarthria, borne and wound rods descending flaccid vegetables such as - inhibits release of dysphagia) anticholinergic effects (dry botulism) paralysis (with green beans, acetylcholine from mouth, constipation, abdominal pain), Culture: requires prominent bulbar peppers and peripheral nerves à bilateral descending flaccid paralysis, Human botulism: anaerobic condition involvement) mushroom: flaccid paralysis respiratory paralysis immunoglobulin (thioglycollate- - Absence of fever Home-canned (descending (for infant botulism) enriched agar) - Intact sensorium Zip-lock pattern) INFANT BOTULISM: when baby ingests Elimination of the storage bags - Eight immunologic spores found in household dust or organism from GIT Patient’s serum BOTOX is a Smoked fish types of toxins honey; due to absence of competitive (Judicious use of injected into mice commercial - Types A, B, and E: bowel microbes; constipation, flaccid gastric lavage and results in death preparation of Wild, raw honey: most common in paralysis (FLOPPY BABY SYNDROME) exotoxin A; used in associated with metronidazole or humans penicillin) wrinkle removal, infant botulism - not secreted, rather WOUND BOTULISM: similar to food- torticollis Bulging canned it is released upon borne except absence of GI prodromal Supportive therapy: goods the death of the symptoms; due to traumatic incubation and bacterium implantation and germination of spores ventilator at the wound site assistance  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Clostridium Ubiquitous: Endospores Anaerobic NON-motile Alpha toxin: GAS GANGRENE Gas Gangrene: Anaerobic, gram- Looks motile, but not perfringens Soil lecithinase (splits - Due to alpha toxin - Wound positive, spore-forming motile on blood agar GI tract of humans Myonecrosis results lecithin into - Gas produced by anaerobic debridement rods à due to avidity for and mammals from contamination of phosphocoline and metabolism - Radical surgery lecithin in the blood wound with soil or diglyceride); cleaves - Pain, edema, and cellulitis with (may require Culture: requires membranes feces cell membranes crepitation amputation) anaerobic conditions - Hemolysis and jaundice are common - Penicillin Food poisoning is 11 other tissue - Hyperbaric Double hemolysis on transmitted by destructive enzymes FOOD POISONING oxygen blood agar ingestion of - Due to production of enterotoxin contaminated food which acts as superantigen Food Poisoning: Growth on egg yolk - Incubation period: 8-16 hours - Supportive agar: non-motile but - Watery diarrhea with cramps and PREVENTION: with rapidly spreading little vomiting Proper wound care growth on culture - Resolves in 24 hours Adequate cooking media Clostridium difficile Carried in the Fecal-oral: ingestion of Anaerobic Motile: Flagella (so H- Exotoxins A and B PSEUDOMEMBRANOUS ENTEROCOLITIS: Metronidazole Anaerobic, gram- PO vancomycin colon: endospores antigen-positive) inhibit GTPases à - antibiotic-associated diarrhea ORAL vancomycin positive, spore-forming because it has poor - 3% of the general apoptosis and death of - antibiotics suppress normal flora, rods intestinal absorption, population Hands of hospital enterocytes à allowing C. difficile to overgrow Withdraw causative hence, “coats” the - up to 30% in personnel are pseudomembranes nd rd - Clindamycin, 2 and 3 generation antibiotic Exotoxin ins tool lesions with antibiotic hospitalized important cephalosporins, ampicillin detected by cytopathic Toxin A: diarrhea Replace fluids effect (final phase by patients intermediaries - non-bloody diarrhea associated with Infection can pseudomembranes (yellow-white Surgery if toxic which viral cells infect precipitate flare-ups Toxin B: cytotoxic to cells) on cultured cells colonic epithelial cells plaques) on the colonic mucosa megacolon of ulcerative colitis - toxic megacolon can occur develops or ELISA Colonoscopy Corynebacterium Throat Respiratory droplets Facultative anaerobe Pseudo-membrane forms in Exotoxin (encoded by DIPHTHERIA Antitoxins Aerobic, non-spore- Schick test: injection diphtheriae from carrier the pharynx, which serves ß-prophage); obtained - Mild sore throat with fever initially forming, non-motile of diphtheria Catalase-positive as a base from where it from a temperate - Pseudomembrane forms on pharynx Penicillin or gram-positive rods; exotoxin into the secretes its toxin bacteriophage by (results from death of mucosal erythromycin Club or comma-shaped skin, to determine lysogenic conversion epithelial cells) rods arranged in V or L whether a person is - Myocarditis Vaccine DPT configuration; looks susceptible to Subunit A: has ADP- î A-V conduction block - DIPHTHERIA: like Chinese characters infection by ribosylating activity; î dysrhythmia formalin- diphtheriae blocks protein - Neural involvement: inactivated Culture: synthesis by î peripheral nerve palsies exotoxin, as Potassium tellurite: inactivating EF2 (which î GBS antibodies to the dark black colonies is involved in translation î palatal paralysis B-subunit are ADP-ribosylation of eukaryotic mRNA into î neuropathies Loeffler’s medium: protective ß-prophage proteins) after 12 hours of - pertussis growth, stain with Corynebacterium - tetanus methylene blue. Diphtheriae Subunit B: provides entry into cardiac and Elongation factor 2 Reddish neural tissue metachromatic (Babes- Granules Ernst / Volutin) Exotoxin is like a granules can be seen “human antibiotic” (inhibits eukaryotic Modified Elek Test: protein synthesis) for detection of toxigenicity  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Listeria Ubiquitous Ingestion of Facultative anaerobe Motile (via flagella): so has The only gram positive EARLY-ONSET NEONATAL LISTERIOSIS Ampicillin Aerobic, non-spore- Facultative monocytogenes Plants (vegetables) contaminated raw H-antigen à tumbling bacteria that produces (Granulomatosis Infantiseptica) +/- Gentamicin forming gram-positive intracellular organism milk or cheese from Catalase-positive motility LPS - transplacental transmission rods, arranged in V- or Colonizes GI and infected cows - characterized by: TMP-SMX L-shape exhibiting Cell-mediated female GUT Listeriolysin O: allows î late miscarriage (if allergic to penicillin) tumbling motility immunity is Vaginally (during escape from the î birth complicated by sepsis, protective birth) phagolysosomes of multiorgan abscesses, and Narrow zone of beta- macrophages; major disseminated granulomas NOT hemolysis Tranplacental virulence factor CEPHALOSPORINS: CAUSES OF infection of fetus from LATE-ONSET NEONATAL LISTERIOSIS None of the Culture: can grow at NEONATAL bacteremic mother Internalin: interacts with E- - transmitted during childbirth cephalosporins are temperature as low as MENINGITIS: cadherin on the surface of - manifests as: active against 4-10C so use cold î GBS cells î meningitis MRSA, LISTERIA, enrichment technique î Escherichia coli î meningoencephalitis AND ENTEROCOCCI to isolate from mixed î Listeria Actin Rockets: propel the flora monocytogenes bacteria through the ADULT LISTERIOSIS membrane of one human - second most common cause of cell into another meningitis in people > 50yo - most common cause of meningitis in immunocompromised patients (with lymphoma, on corticosteroids or receiving organ transplantation) - septicemia in pregnant women GRAM-POSITIVE WITH BRANCHING FILAMENTS Nocardia asteroides Actinomyces israelii Aerobe Anaerobe Weakly Acid fast (Fite-Faraco Stain) Not acid-fast Found in soil Normal oral, reproductive, and GI flora Pulmonary infections in immunocompromised (can mimic Oral/facial abscesses that drain through sinus tracts TB but with negative PPD) Often associated with dental caries/extraction cutaneous infections after trauma in immunocompetent Forms yellow “sulfur granules” can spread to CNS à brain abscesses (orange colonies) Can cause PID with IUDs Treatment: Sulfonamides (TMP-SMX) Treatment: Penicillin Treatment is a SNAP: Sulfonamides—Nocardia; Actinomyces —Penicillin OTHER CLOSTRIDIA C. septicum Nontraumatic myonecrosis in immunocompromised patients C. sordellii Toxic shock syndrome associated with septic abortion C. tertium Traumatic wound infections  GRAM-NEGATIVE BACTERIA GRAM-STAIN OTHER FEATURES ORGANISM Encapsulated Gram-Negative Ferments maltose and glucose Neisseria meningitidis Diplococci Insignificant capsule Neisseria gonorrheae Ferments glucose only Other Neisseriaceae Eikenella corrodens and Kingella kingae cause culture-negative subacute bacterial endocarditis in patients with preexisting heart disease HACEK Organisms GRAM-NEGATIVE RODS – RESPIRATORY SYSTEM GRAM-STAIN OTHER FEATURES ORGANISM Enriched chocolate agar Haemophilus influenzae Polyribitol Phosphate capsule type B Borget-Gengou Agar Gram-Negative Regan-Lowe medium Bordetella pertussis Whooping cough Rods Poorly gram staining Silver stain Legionella pneumophila Charcoal yeast agar AIrconditioning GRAM-NEGATIVE RODS – GIT and GUT GRAM-STAIN OTHER FEATURES ORGANISM ENTEROBACTERIACEAE Lactose fermenters Escherichia coli MESSY SPECK Green sheen Lactose fermenters Morganella Serratia Urease positive Klebsiella pneumoniae Escherichia Proteus ESBL Gram-Negative Shigella Enterobacter Comma-shaped Rods Microaerophilic Campylobacter jejuni Salmonella Citrobacter Skirrow’s agar Yersinia Klebsiella Comma-shaped Urease positive Helicobacter jejuni Microaerophilic Enterobacteriaceae drink COFFEe! Motile Oxidase negative Salmonella spp. Capsular antigen (K) H2S producer O antigen Non-motile Oxidase negative Shigella spp. Flagellar antigen Non-lactose- H2S non-producer Ferments glucose fermenting, Gram- Swarming Enterobacteriaceae Negative Rods Oxidase negative Proteus mirabilis H2S producer Urease positive Oxidase positive H2S non-producer Pseudomonas aeruginosa Obligate aerobe ANTIMICROBIAL PROPHYLAXIS  TREATMENT AND MICROORGANISM RESERVOIR TRANSMISSION METABOLISM VIRULENCE FACTORS TOXINS CLINICAL SYNDROMES DIAGNOSIS NOTES PREVENTION Neisseria Upper respiratory Respiratory droplets Ferments both Capsule: Endotoxin (LPS) MENINGITIS: Penicillin Gram-negative, Neisseria meningitidis tract MALTOSE and î 13 serotypes based on î most common cause among aged aerobic, encapsulated, MeninGitidis High carriage rate in GLUCOSE antigenicity of capsule No exotoxins 2-18 yrs Ceftriaxone (or kidney bean-shaped Ferments both HUMANS are the CLOSE QUARTERS: polysaccharides î fever, headache, stiff neck, and cefotaxime): DOC for diplococcus only natural î Military recruits Oxidase-positive î Serotypes A, B, & C are increased level of PMNs in CSF the treatment of Maltose and hosts. î Dormitories colonies on associated with epidemics meningococcal meningitis Culture specimen on Glucose î Camps chocolate agar of meningitis (usually type MENINGOCOCCEMIA: and septicemia blood agar that has B) î dissemination of meningococci into been heated to 80°C