Other Fastidious Gram Negative Rods PDF

158 O'fher Fastidious Gram Negative Rods ORGANISM DESCRIPTION DISEASE NOTES Bordetella pertussis Gram Neg Coccobacillus; Pinpoint, Pertussis ( Whooping Bordet-Gengou...

158 O'fher Fastidious Gram Negative Rods ORGANISM DESCRIPTION DISEASE NOTES Bordetella pertussis Gram Neg Coccobacillus; Pinpoint, Pertussis ( Whooping Bordet-Gengou Media; NP Swab "Mercury Droplet" Colonies Cough) and Plate Directly Haemophilus Small, Non-Motile Gram Neg Rods H. influenzae - Causes Require X and V Factors H. ducreyi - "School of Fish" Influenza, Meningitis, and Epiglottitis H. ducreyi - Causes Genital Ulcers Legionella pneumophilia Growth on BCYE Legionnaires' Disease No Growth Routine Media Mycoplasma/Ureaplasma Colony Appears as Inverted Fried Egg M. pneumoniae - Dienes Stain NOT Gram Stain Causes Primary Atypical Pneumonia (-i-Cold Agglutinin Titer) Anaerobes 1. Clues to anaer obic infection 3. Culture techniques a. Foul odor to specimen a. '"Classic" principle of anaerobic b. Location in close proximity to a culture mucosal surface ! Jar technique (Gas Pak jar) c. Animal or human bite ! Catalyst - palladium p ellets d. Gas in specimen ♦:♦ Envelope generates H2 and CO2 e. Previous therapy with when water is added aminoglycosides ♦:♦ Methylene blue or resazurin - f. Black discoloration of blood indicators (blue and pink, containing exudates respectively when oxidized ; clear g. Presence of " sulfur granules" when reduced) h. Unique mor phology on gr am stain b. Other methods i. Failure to gr ow or ganism s seen on ♦:♦ Anaerobic bags - clear bag with smear aerobically gas gen erating ampules; plates can j. Growth in anaerobic zone or be read without opening bag bubbles in fluid media ❖ Roll tube technique ~ PRAS (pre-reduced 2. Specimen collection and transport anaerobically sterilized a. Site containing a r esident flora m edia) inoculated under (oral, GI, GU) not appropriate for constant flow of 0 2 - free gas anaerobic culture ❖ Anaerobic chamber b. Best to a spirate with syringe and ~ Plates put in chamber needle and place in a transport vial throu gh a pass box that is or tube under r educed conditions r educed (swab samples not as good) ~ Incubator in chamber ; also contains palladium catalyst  159 EXAMINATION OF PRIMARY PLATE 6. KVLB - look for pigment and examine 1. Pitting - Bacteroides ureoly ticus ( could under UV light h e Eiken ell.a) a. P erform a erotolerance test on colonies by subculturing each 2. Lar ge colonies with double zone of colony type to an anaer obic blood hemolysis - Clostridium perfringen s; set plate and a chocolate plate up egg yolk agar for N aegler test b. Incubate chocolate at 36°C under 5-10% CO2 and the anaerobe BAP 3. Bread crumb or speckled colonies; at 36°C in a ga s jar or anaerobe gram negative slender fu siforms - ch amber Fusobacterium nucleatum c. If growth on both, the organism is 1. Molar tooth colonies of Cram positive facultative; if growth only on branching rods - A ctinomyces anaerobic blood , the organism is an anaer obe 5. BBE - dark colonies,> 1 mm - Bacteroides fragilis Differentiating Gram Negative Anaerobes V anc omy cin Kanamycin Col istin lndole Lipase E scu lin H2 S N otes (Sµg) (1 mg) (10µg) V - Bacteroides frag/lis R A A + - Catalase +, b lack c olonies on BBE May fluoresce brick-red, Pigmented Gram Negative Rods s A V + V - - may produce black ninment Bacteroldes ureo/yticus R s s - - - - P i ts agar; urease + Fusooacterlum s s - T hin, fusiform rod s, nucleatum A + - - speckled colonies Fusobacter;um necrophorum R s s + + - + Rods variable In len gth and wi dth Fusobacterium mort;ferum R s s V - + + High ly pleomorph ic rods I R = resistant S = sensitive V = variable I Differentiating Gram Positive Anaerobes ORGANISM CHARACTERISTICS Organism associated with PMC C/ostridium difficile Pseudomembranous Colitis (PMC); Usually ID with immunodiagnostic tests; Emeri;;ing resistant strains; CCFA Agar ( 'Horse Stable" Odor); Organism Associated with Spore Former Lumpy Jaw and Clostridium perfringens "Sulfur" Granules Double Zone of I lemolysis; Lecithinase +; Gas Gangrene; Spores Seldom Observed Spirochetes Clostridium tetani Terminal Spores ("Racquet-Shaped"); TREPONEMA PAWDUM Tetanus 1. Stain with silver impregnation Actinomyces israe/ii "Molar Tooth" Colony; Branchin~ Gram + Rods ("Lumpy Jaw"); Sulp ur 2. Darkfield - slow motility and flexion Granules P anaerobius Sensitive to SPS 3. No growth on artificial media 4. Sen sitive to p enicillin, tetracycline and erythromycin 160 5. Detected through serological tests (see e. Culture in Kelly medium at 33°C - Serology/Immu.nology for details) darkfield weekly for 1 month f. Serological diagnosis faster 6. Syphilis a. Primary lesion ❖ 2-10 week s after infection, chancre appears ❖ Heals without treatment in 3-8 weeks; may perfo.rm darkfield or Cause, Vector and Culture direct FA on fluid Media of b. Secondary lesion Lyme Disease ❖ Dissemination - skin rash c. Latent stage ❖ 2-20 yrs later ❖ Affects skin, bone, joints, CNS LEPTOSPIRA II 1. Spirals with hooked ends Chlamydia/es 2. Animal pathogen passed to humans via 1. Obligate intracellular parasites water contaminated with animal urine (ex. sewer workers, farmers, vets) 2. Gram negative cell wall, with no peptidoglycan; possess ribosomes for 3. Positive darkfield or direct FA protein synthesis 4. Can grow in Fletcher's semi-solid media 3. Dependent on host for ATP a. Incubate 6 wks at 30°C in the dark b. Perform darkfield from several 4. Laboratory diagnosis centimeters into media a. Giemsa stain (purple inclusion bodies) or iodine stain 5. Growth in yolk sac of chick embryo or tissue culture (McCoy cell) 6. Chlamydia trachomatis a. Genital tract infections (sexually transmitted disease) ❖ Non-gonococcal w·ethritis and BORRELIA epididymitis in males ❖ Cervicitis and salpingitis (PID) in 1. B. recurrentis females a. "Relapsing fever" from ticks or lice ❖ Can be passed to newborn as b. Looser coils; best seen with Giemsa conjunctivitis or pneumonia or Wright's stain of blood smear b. Eye infections c. Mutates during disease; relapse due ❖ Trachoma - leading cause of to inability to recognize new antigen blindness in underdeveloped d. May exhibit cross reaction with countries Proteus OX K on febrile ❖ Inclusion conjunctivitis agglutinations with titer up to 1:80 c. Most ID by probe technology 2. B. burgdorferi 7. Chlamydophila psittaci a. Lyme disease a. Psittacosis (parrot fever ) - b. Transmitted by Ixodes ticks (deer occupational hazard for pet bird or mouse tick) handlers and poultry workers c. Northeastern and N. Midwest US b. Acute lower r espiratory infection d. Chronic migratory er ythematous rash, fever, muscle and joint pain; 8. Chlamydophila pneumoniae later meningioencephalitis, a. Grown in HELA cells myocarditis and arthritis b. Respiratory pathogen c. Linked to cardiovascular disease  161 Rickeffsiae 5. Arthropod bite - causes fever, h eadach e, r ash (Q fever - no rash and 1. Small gram negative coccobacilh organism s urvives outside host) 2. Obligate intracellular parasites 6. Weil-Felix test 3. Spr ead by arthropod (insect) vectors a. Proteu s OX-19, OX-2 and OX-K u sed as antigen s to detect 4. Seen better with Giemsa Rickettsial antibody b. 4-fold rise in titer or l: 160 titer Most Common Rickeffsiae ORGANISM VECTOR PROTEUS NOTES OX19 OX 2 OX K R. akari House - - - (Rickettsial Pox) Mites Coxiella burnetti Inhaled - - - Confirm with CF Test (Q Fever) R. prowazekii Louse + Variable - (Typhus Fever) R. rickettsiae Tick + + - Characteristic Rash on Palms of Hand (Rocky Mt. Spotted Fever) and Soles of Feet R. typhi Rat Flea + + - (Murine Typhus) Acid Fast Bacilli 6. Gr owth requirements a. Lowenstein-Jensen; 60% egg in nutrient base; malachite green; asic solidified into slants after inspissation lde1Jtjfy (h eat to 85°C until protein coagulates) b. Tween 80 (oleic acid) - aids in Mycobacteria dispersing colonies in liquid media 1. Morphology - slim gram variable rods; c. ,t.C02 (especially in first 24 hrs) don' t gram stain well due to high lipid d. Most grow at 36°C; some require content in wall 3o c e. Takes 3-6 weeks for growth 2. Acid fast stain f. Automated liquid culture systems a. Ziehl-Neilsen - " hot" stain for rapid growth & susceptibility b. Kinyoun - "cold" stain testing 3. Auramine-Rhodamine - fluorescent 7. Identification by nucleic acid probe stain SPECIMEN COLLECTION 4. All stains based on presence of mycolic 1. Sputum (first morning; on 3 acid (lipid-wax) in cell wall consecutive mornings), bronchial & gastric washings, urines and tissue 5. Any number seen on a smear is significant 2. Collect a septically and place in sterile , tightly capped container 3. May be refrigerated overnight (neutralize gastrics and urines ifholding overnight)