Bacteriology Flashcards
What is the drug of choice for all rickettsial infections?
Doxycycline
What organism present with atypical pneumonia and associated with atherosclerosis?
Chlamydia pneumoniae
What causes Q fever and has no vector, no rash, no weil-felix reaction and has a 65% mortality?
Coxiella burnetti
What do you call the cross reaction with antigens of OX stains of Proteus vulgaris?
Weil-Felix reaction
What organism causes Cat Scratch Disease?
Bartonella Henselae
Organism that cause mesenteric adenitis (pseudoappendicitis), gram negative rods, oro-fecal route of transmission and domestic animals as reservoir
Yersinia enterocolitica
Organism that is catalase positive and coagulase positive
Staphylococcus aureus
Organism that is catalase positive, coagulase negative, novobiocin sensitive
Staphylococcus epidermidis
Organism that is gram positive cocci in clusters, catalase positive, coagulase negative, and novobiocin resistant
Staphylococcus saprophyticus
Organism that is gram positive cocci in chains, catalase negative, alpha hemolytic, bile-optochin-sensitive
Streptococcus pneumoniae
Gram-negative diplococci Oxidase-positive on chocolate agar Ferments maltose and glucose Complement deficiencies in late-acting complement components (C5-C9)
Neisseria meningitidis
Spectrum of disease of Neisseria menigitidis
Meningitis Meningococcemia Waterhouse-friderichsen syndrome
Neisseria gonorrhoeae is oxidase positive on _____.
Thayer-Martin medium
Treatment of Neisseia gonorheoae when co-infected with Chalmydia trachomatis
Ceftriaxone + doxycycline
Other Neisseriaceae that cause culture-negative subacute bacterial endocarditis in patients with pre-existing heart disease
Eikenella corrodens Kingella kingae
Haemophilus influenzae requires (1) _____ (hemin) and (2) _____ (NAD) for growth on chocolate agar, and causes a Satellite Phenomenon on (3) _____ colonies.
(1) factor X (2) factor V (3) Staphylococcus aureus
This vaccine contains the type b capsular polysaccharide conjugated to diphtheria toxoid, and is given between 2 and 18 months of age.
Haemophilus influenzae b vaccine
Grows on Bordet-Gengou agar or Regan-Lowe charcoal medium Habitat is the upper respiratory tract Transmitted via respiratory droplets Causes whooping cough
Bordetella pertussis
3 most common cause of atypical pneumonia
Mycoplasma pneumoniae Legionela pneumophila Chlamydia pneumoniae
Spectrum of disease of atypical pneumonia in Legionella pneumophila
Pneumonia Confusion Nonbloody diarrhea Hyponatremia Proteinuria Hematuria
Facultative intracellular bacteria
Some Bugs May Live FacultativeLY Salmonella Brucella Mycobacterium Listeria Francisella Legionella Yersinia
Lactose-fermenting colonies on Eosin-Methylene Blue or MacConkey’s agar Triple sugar iron agar shows acid slant and acid butt with gas but no H2S Typing by O and H antigen Most common cause of community-acquired UTI Second most common cause of Neonatal meningitis
Escherichia coli
Match the antigen with the pathogen Antigen: H, K, O Pathogen: capsule, endotoxin, flagellum
Flagellum - H Capsule - K Endotoxin - O
Treatment for Escherichia coli infection (1) worldwide (2) Philippines
(1) ampicillin or sulfonamides (UTI), 3rd generation for meningitis and sepsis (2) quinolones
Antigen that causes typhoid fever that can result in the establishment of a chronic carrier state
Vi capsular antigen
Incubation period of 12-48 hours Nausea and vomiting and then progresses to abdominal pain and nonbloody diarrhea
Enterocolitis (Salmonella enteritidis / Salmonella typhimurium)
Chloramphenicol is used for the treatment of Salmonella infection. It is also used for the empiric treatment of meningitis. What are the other common causes of meningitis?
Neisseria meningitidis Bacteroides fragilis Streptococcus pneumoniae Haemophilus influenzae
Shigella dysenteriae type 1: _____ bacillus Shigella sonnei: _____ bacillus
Shiga bacillus Duval’s bacillus
Non-lactose fermenting, gram-negative rods Produce no gas from the fermentation of glucose Do not produce H2S Nonmotile Have O antigens Cultured inXLD medium
Shigella spp.
Habitat: saltwater Transmission: contaminated raw seafood Spectrum of disease: gastroenteritis, wound infections
Vibrio parahaemolyticus
Enterotoxin of Vibrio that acts by ADP-ribosylation
Choleragen
Most common cause of bacterial gastroenteritis Produces histologic damage to the mucosal surafces of the jejunum Watery, foul-smelling diarrhea followed by bloody stools Associated with Guillain-Barrè syndrome and Reiter’s syndrome
Campylobacter jejuni
Urease-positive bacteria
Particular Kinds Have Urease Proteus mirabilis Klebsiella pneumoniae Helicobacter pylori Ureaplasma urealyticum
Facultative gram-negative rods with large polysaccharide capsule Extended spectrum beta-lactamase activity in drug-resistant strains Urease-positive Necrotizing pneumonia with currant-jelly sputum
Klebsiella pneumoniae
Proteus mirabilis isnassociated with complicated UTI, particularly those that form staghorn calculi on renal calyces. What type of motility is exhibited by this bacteria?
Swarming motility
Gram-negative rods Obligate aerobe Non-lactose fermenting Oxidase-positive Grown on Cetrimide agar Seen in many diseases such as: hot tub folliculitis, burn wound infections, otitis externa, CSOM, VAP, high-risk CAP, tyhplitis, Shanghai fever, perionitis (in those undergoing PD), nosocomial UTI, ecthyma gangrenosum
Psudomonas aeruginosa
Toxin of Pseudomonas aeruginosa that causes tissue necrosis and inactivates EF-2, with type III secretion systemthat facilitates the toxin’s transfer
Exotoxin A
Grape-like clusters Beta hemolytic yellow or golden colonies on blood agar Catalase and coagulase positive Salt tolerant on 1)_______ Gold color due to 2) ________ What is this organism?
1) Mannitol Salt Agar 2) Staphyloxanthin pigment Staphylococcus Aureus
This organism has Protein A, Coagulase, Hemolysins, PV Leukocidin, Catalase, and Penicillinase. What is the organism and what do you call these immunomodulators?
Staphylococcus aureus and these are immunomodulators. (Note: Definition of Terms Protein A: Prevents complement activation Coagulase:Builds an insoluble fibrin capsule Hemolysins: Toxic to hematopoietic cells PV leukocidin: Specific for white blood cells Catalase:Detoxifies hydrogen peroxide Penicillinase: Inactivates penicillin derivatives)
This organism can hydrolyze hyaluronic acid, dissolve fibrin clot and spread in fat-containing areas of the body. It can also cause epidermal separation, necrosis of the skin and hemolysis, cause food poisoning and can lead to TSS. What is this?
Staphylococcus aureus [Note: Definition of Terms Hyaluronidase: hydrolyzes hyaluronic acid Fibrinolysin/Staphylokinase: dissolves fibrin clot Lipase: spread in fat-containing areas of the body Exfollatin: causes epidermal separation Heat-stable Enterotoxins: superantigens causing food poisoning Toxic Shock Syndrome toxin (TSST-1): superantigen leading to TSS Alpha Toxin: causes marked necrosis of the skin and hemolysis]
Most common cause of acute endocarditis and what valve is usually involved in IV drug abusers? Also causes penumonia, osteomyelitis, brodie abscess and septic arthritis.
Staphylococcus aureus Tricuspid valve (Brodie abscess: sequestered focus of osteomyelitis arising in the metaphyseal area of a long bone)
Causes bullous impetigo, folliculitis, furuncles, carbuncles, cellulitis, hidradenitis suppurativa, mastitis and surgical site infections.
Staphylococcus aureus (Examples of skin and soft tissue infections caused by S. aureus)
Treatment for S. aureus? MSSA, MRSA and VRSA
Methicillin sensitive: penicillinase-resistant penicillins like Nafcillin, Oxacillin and Dicloxacillin Methicillin resistant: Vancomycin Vancomycin resistant: Linezolid
Fever, hypotension, sloughing off of the filiform papillae in the tongue, desquamating rash, multi-organ involvement, blood CS negative What presents with these and what is the organism responsible?
Toxic shock syndrome Staph aureus (Note: due to TSST-1 Usually there is no site of pyogenic inflammation that’s why blood CS is negative Usual patients are those that uses tampons and who have nasal packing)
Difference of TEN and Ritter disease?
Both affects the skin Ritter: separation of epidermis at STRATUM GRANULOSUM because exfollatin cleaves desmoglein in desmosomes. Organism involved is Staph aureus TEN: separation occurs at the dermo-epidermal junction Ritter disease is Scalded Skin Syndrome TEN is Toxic Epidermal Necrolysis
Low virulence organism Forms biofilm because its glycocalyx adheres well to foreign bodies Transmitted through autoinfection or direct contact What is the organism and what are the diseases it causes?
Staphylococcus Epidermidis It is the most common cause of: Prosthetic valve endocarditis Septic arthritis in prosthetic joints Ventriculoperitoneal shunt infections
Gram positive cocci in clusters Catalase positive Coagulase negative Novobiocin sensitive Normal skin flora What is the treatment if you get infected?
Removal of prosthetic device Vancomycin because over 50% are methicillin resistant (Organism: Staph epidermidis)
What is the 2nd most common cause of UTIs in sexually active women?
Staphylococcus saprophyticus (#1: E. coli)
Gram-negative rods Predominant anearobe of human colon Associated with spread during bowel trauma, perforation or surgery Infections due to combinations of bacteria in synergistic pathogenicity
Bacteroides fragilis
Zoonoses
Bugs From Your Pets Brucella abortus (Bruce the cow) Francisella tularensis (Francis the rabbit) Yersinia pestis (Yeye the rat) Pasteurella multocida (Papa the cat)
Brucellosis is associated with undulating fever. What medium is used to identify this organism?
Castañeda medium
Treatment for Tularemia from Francisella tularensis
Streptomycin / Gentamicin
What disease did Yersinia pestis cause that made it the most virulent bacteria?
Bubonic, pbeumonic and septicemic plague
The buttery colonies with musty odor in Pasteurella multocida infection is due to?
Indole production
Mycobacterium tubeculosis uses (1) What stain? (2) What medium? (3) What assay for drug resistance?
(1) Zieh-Neelsen or Kinyoun stain (2) Löwenstein-Jensen medium (3) Luciferase assay
Mycobacterium tuberculosis virulence factors: (1) exported repetitive protein that prevents phagosome-lysosomal fusion (2) most important virulence factor (3) elicits delayed hypersensitivity
(1) sulfatides (2) cord factor (3) tuberculin surface protein
In Mycobacterium tuberculosis, (1) granulomatous lesions exhibit a central area of these cells surrounded by a zone of epithelioid cells = _____ (2) primary complex have subpleural granuloma + associated lymph node = _____ (3) reactivation tuberculosis is usually occurs in apices and is seen as this = _____
(1) Langhan’s giant cells (2) Ghon’s complex (3) Simon’s focus
This bacteria causes pulmonary disease in the immunocompromised, most especially AIDS patients with CD4 < 50
Mycobacterium avium - intracellulare complex
(1) This bacteria’s reservoir are humans and armadillos. One of its spectrum of disease exhibits the following characteristics: (a) few lesions, little tissue destruction, few AFB, low likelihood of transmission, with cell-mediated response to the bacteria, positive skin test (b) many lesions, marked tissue destruction, many AFB, high likelihood of transmission, reduced cell-mediated response to the bacteria, negative skin test
(1) Mycobacterium leprae (a) Tuberculoid leprosy (b) Lepromatous leprosy
Hard, nontender swelling with sinus tracts draining sulfur granules Treated with Penicillin G + drainage
Actinomycosis (Actinomycoses israelii)
Obligate intracellular bacteria
Ricketssia Chlamydia
Cell wall lacks muramic acid Grown in cycloheximide culture Cytoplasmic inclusions in Giemsa Balance is often reached between host and parasite, resulting in prolonged persistance of infection Infection persists in the presence of high antibody titers This organism has 2 forms: (1) inactive, extracellular, enters cells by endocytosis (2) metabolically active, intracellular, seen microscopically as inclusion bodies
Chlamydia trachomatis (1) elementary body (2) reticulate body
Spectrum of disease of Chlamydia trachomatis (1) types A-C, chronic keratoconjunctivitis, Halberstadter-Prowazek inclusions (2) types D-K, most common cause of STDs, neonatal conjunctivitis (ophthalmia neonatorum), neonatal pneumonia, associated with Reiter’s syndrome (3) types L1-L3, buboes (papule or vesicles which ulcerates and leads to suppurative inguinal lymphadenitis), positive Frei test
(1) Trachoma (2) Genital tract infections (3) Lymphogranuloma venereum
Atypical pneumonia associated with atherosclerosis
Chlamydia pneumoniae
Bird fancier’s disease
Psittacosis (Chlamydia Psittaci)
Generalization of treatment for Chlamydia STD : _____ _____ : erythromycin _____ : doxycycline Psittacosis : _____
STD : azithromycin Conjunctivitis : erythromycin LGV : doxycycline Psittacosis : azithromycin
Rickettsiae is classically detected using _____, which is done by the cross-reaction with antigens of OX strains of Proteus vulgaris.
Weil-Felix reaction
Cat-scratch fever in immunocompetent individuals Bacillary angiomatosis in immunocompromised
Bartonella henselae
Transmitted by dog tick bite Forms morulae in cytoplasm of monocytes
Ehrlichiosis (Ehrlichia chaffensis)