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CAPNOCYTOPHAGA
• Normal microbiota of the oral cavity of humans
• Causes septicemia in patients with neutropenia
• Fastidious, facultative anaerobe
• Thin and often fusiform (pointed ends) resembling Fusobacterium spp.
• No flagella but can produce gliding motility on solid surfaces
• (+) Ferment sucrose, glucose, maltose, and lactose
• (-) Indole negative
Blood cultures from patients who have neutropenia with oral ulcers
(source of the Capnocytophaga)
Capnocytophaga ocracea
Most common clinical isolate
Capnocytophaga canimorsus and Capnocytophaga cynodegmi
Normal inhabitants of the oral cavity of dogs and cats Infection from dog or cat bite
LEGIONELLA
• Non-spore forming, thin, gram-negative bacilli • Faintly staining • Found in the environment especially water
LEGIONELLA
• Tolerate chlorine concentrations of 3 mg/L
LEGIONELLA
• Transmission: exposure to contaminated water (faucets, showerheads, public fountains, aircon) • Reservoirs: Hot water systems, cooling towers, and evaporative condensers are major reservoirs
LEGIONELLA
First recognized to cause human disease during an epidemic of pneumonia that occurred among members of the Pennsylvania American Legion who had gathered in Philadelphia to celebrate the 1976 bicentennial
Legionella pneumophila
Legionella was first recognized to cause human disease during an epidemic of pneumonia that occurred among members of the Pennsylvania American Legion who had gathered in Philadelphia to celebrate the 1976 bicentennial. The causative agent was?
Intracellular pathogens
Legionella has the ability to exist as pathogens (amebae and mammalian cells)
Phagolysosome
Legionella can survive inside phagosomes, prevent the formation of _
Multiply and survive
Legionella has the ability to _________over the temperature range of 20C to 43C and _ for varying periods at 40C to 60C
Legionella
has the capacity to adhere to pipes, rubber, plastics, and sediment and persist in piped water systems, even when flushed.
Legionnaire’s Disease
• Febrile disease with pneumonia
• Predominant manifestation: pneumonia
• Community acquired bacterial pneumonia Incubation Period: 2-10 days
Pontiac Fever
Influenza-like febrile disease
• Non-pneumonic form of legionellosis
• Inhalation of bacterial toxins or an acute allergic reaction to the bacteria
• Previously healthy individuals who complain of flu-like symptoms
Pontiac Fever
causes myalgia that lasts 2 to 5 days and then subside without medical intervention
Legionnaire’s disease
LD (Lab Diagnosis) uses combination of culture and urine antigen detection
Serology
Lab diagnosis for pontiac fever
Microscopic examination of Legionella
Pleomorphic, weakly staining, gram-negative bacilli found outside of and within macrophages and segmented neutrophils
Diff- quik
a stain used in ME for Legionella
BCYE (Buffered charcoal yeast extract) agar with L cysteine
Best culture media for Legionella isolation
Legionella on BCYE
grayish white or blue-green, convex, and glistening, measuring approximately 2 to 4 mm in diameter
Legionella on BCYE
Central portion of young colonies has a “ground-glass” appearance, light gray and granular
Legionella on BCYE
The periphery of the colony has pink or light blue or bottle green bands with a furrowed appearance
Selective BCYE agar
contains polymyxin B, anisomycin, and either vancomycin or cefamandole
Legionella
Fastidious, aerobic bacteria that do not grow on SBA and require L-cysteine for growth and needs ACID treatment of specimen before inoculation
Acid treatment
Since we are treating a non-sterile specimen, it should first have a pre-treatment in order to kill the bacteria so only Legionella will remain. This is done through
1:10 with 0.2N potassium chloride, 4 minutes – hydrochloric acid
Aliquot of the Legionella specimen is first diluted in and is allowed to stand for no more than ____
1:10 in tryptic soy broth or distilled water
Specimens from normally sterile sites should be diluted (Done in order to dilute microbial inhibitors such as complement antibodies and antimicrobial agents)
WHOOPING COUGH OR PERTUSSIS
• Transmission occurs person to person through inhalation of respiratory droplets
• Highly contagious, acute infection of the upper respiratory tract
• Caused by Bordetella pertussis
CATARRHAL STAGE
• Symptoms are the same as for a mild cold with a runny nose and mild cough
• Lasts several weeks
PAROXYSMAL STAGE
• Severe and violent coughing
• 15 to 25 paroxysmal coughing episodes can occur in 24 hours
• Vomiting and “whooping” (the result of air rapidly inspired into the lungs past the swollen glottis)
• Lasts 1-4 weeks
CONVALESCENT PHASE
• Begins within 4 weeks of onset with a decrease in frequency and severity of the coughing spells
• Cause mild illness and symptomatic infection, primarily in household contacts and in a number of unvaccinated and previously vaccinated children
Fimbriae (FIM), types 2 and 3
Serotype-specific agglutinins for colonization of respiratory mucosa
Filamentous hemagglutinin (FHA)
Mediates adhesion to the ciliated upper respiratory tract
Pertactin (PRN)
: Mediates eukaryotic cell binding and is highly immunogenic
Pertussis toxin (encoded by the ptx gene, an A/B toxin related to cholera toxin)
: Induces lymphocytosis and suppresses chemotaxis and oxidative responses in neutrophils and macrophages
Adenylate cyclase toxin
: Hemolyzes red cells and activates cyclic adenosine monophosphate, thereby inactivating several types of host immune cells
Dermonecrotic toxin
Exact role unknown
Tracheal cytotoxin
Ciliary dysfunction and damage
Endotoxin
Lipopolysaccharide
Outer membrane
: Inhibits host lysozyme
Siderophore production
: Prevents host lactoferrin and transferrin from limiting iron
ciliated epithelium
Specimens for Bordetella obtained from the throat, sputum, or anterior nose are not accepted because these sites are not aligned with ___
Half-strength Regan-Lowe agar
: enhances recovery when used as a transport and enrichment medium
Cold casein hydrolysate medium, Casamino acid broth, Half-strength Regan-Lowe agar
transport medium for Bordetella
Bordet-Gengou
: Potato infusion agar with glycerol and sheep blood with methicillin or cephalexin (short shelf-life)
Cephalexin
is superior to methicillin and penicillin for inhibiting normal respiratory flora
Modified Jones Kendrick charcoal
: Charcoal agar with yeast extract, starch, and 40 ug cephalexin (2- to-3-month shelf-life but inferior to Regan-Lowe agar)
Regan-Lowe
: Best for the recovery of B. pertussis from nasopharyngeal swabs
Stainer-Scholte
: Synthetic agar lacking blood products
mercury drops
Young colonies of B. pertussis and B. parapertussis: “__ ”
Erythromycin
: Drug of choice for pertussis
Zoonosis
a disease that humans acquire from exposure to infected animals
PASTEURELLA
• Normal flora of oral cavity in birds and mammals
• Soft tissue (cutaneous) infection from animal bites
PASTEURELLA MULTOCIDA
• Commensal found in nasopharynx and gastrointestinal tract of wild and domestic animals
• Potential upper respiratory commensal in humans having extensive occupational exposure to animals
PASTEURELLA MULTOCIDA
• MOT: Bite or scratch from variety of veterinary hosts (usually feline or canine) Infections may be associated with non bite exposure to animals Less commonly, infections may occur without history of animal exposure
PASTEURELLA CANIS
• Dogs
• Gram-negative coccobacilli
• Non-motile
• Facultative anaerobic coccobacilli
• Bipolar staining: “Safety pin” appearance
PASTEURELLA CANIS
LABORATORY DIAGNOSIS • (+) Growth on SBA and CHOC agar
• Nonhemolytic colonies on SBA that may appear mucoid after 24 hours of incubation at 37C
• Grayish colonies
• Production of a narrow green-to-brown halo around the colony after 48 hours
Brucellosis
is a zoonotic disease
BRUCELLA
Small, facultative, intracellular, nonmotile, aerobic, gram-negative coccobacilli or short rods
BRUCELLA
A cause of devastating economic loss among domestic livestock, Considered category B select biological agents by the CDC
BRUCELLA
Occurs worldwide, especially in:
o Mediterranean and Persian Gulf countries
o India
o parts of Mexico
o Central and South America
BRUCELLA
MODE OF TRANSMISSION (Humans can be infected by:) - Ingestion of infected unpasteurized animal milk products (most common means of transmission)
Brucella abortus
Cattle
Brucella melitensis
Sheep or goats
Brucella suis
Swine
Brucella canis
Dogs
Brucella ovis
Rams (not associated w/ human infection)
Brucella neotomae
Desert and wood rats
BRUCELLA
Colonies appear small, convex, smooth, translucent, nonhemolytic, and slightly yellow and in Gram stain: Small coccobacilli that resemble fine grains of sand
FRANCISELLA
• Facultative
• Intracellular pathogens
• Nonmotile
• Non-spore forming
• Strict aerobes
• Require cysteine, cystine, or another sulfhydryl and a source of iron for enhanced growth
• (-) Oxidase
• (-) Urease
• (+) Catalase
FRANCISELLA
•Infection is also called: Rabbit fever Deerfly fever Lemming fever Water rat trappers’ disease
FRANCISELLA TULARENSIS
• Causes human and animal tularemia
• Wild rodents, rabbits, beavers, and muskrats in North America
• Humans become infected by handling the carcasses or skin of infected animals
• Inhaling infective aerosols or ingesting contaminated water
FRANCISELLA TULARENSIS
Through insect vectors (primarily deerflies and ticks in the United States)
• Being bitten by carnivores that have themselves eaten infected animals
Tularemia
is one of the most common laboratory acquired infections
F. tularensis subsp. tularensis
Most severe: Tularemia (all forms) and requires cysteine
F. tularensis subsp. holartica
Least severe: Tularemia (all forms) and require cysteine
Systemic (typhoidal) tularemia
acute illness with septicemia; 30% to 60% mortality rate; no ulcer or lymphadenopathy
Pneumonic tularemia
acquired by inhalation of infectious aerosols or by dissemination from the bloodstream; pneumonia; most serious form of tularemia
BSL II
F. tularensis is a BSL __ pathogen
GARDNERELLA VAGINALIS
• Thin, gram-variable rod or coccobacillus
• Part of the anorectal flora of healthy adults of both sexes, as well as of children
• Part of the endogenous vaginal flora of women of reproductive age
GARDNERELLA VAGINALIS
• Causes bacterial vaginosis
• Has been called Haemophilus vaginalis and Corynebacterium vaginale
Clue cells
: epithelial cells covered with bacteria on the cell margins used in the diagnosis of vaginosis
GARDNERELLA VAGINALIS
Fishy amine odor after addition of 10% potassium hydroxide (KOH) to the secretions
STREPTOBACILLUS
• Facultatively anaerobic
• Fermentative
• Non-encapsulated
• Nonmotile
• Pleomorphic gram-negative rod
• String-of-beads appearance
STREPTOBACILLUS MONILIFORMIS
• Rat-bite fever or Haverhill disease
• Indigenous flora in the upper respiratory tract of wild and laboratory rodents
STREPTOBACILLUS MONILIFORMIS
• Local lymphangitis and lymphadenitis, migratory polyarthritis
• Fever, chills, malaise, and, later, a general morbilliform maculopapular or petechial rash
False-negative
Whole blood is acceptable in Francisella but results may occur during early stages of disease