Question | Answer |
What organism has an elongated body that is tapered at both ends, is covered in a cuticle, and has separate sexes in all species? | Nematodes |
Nematode eggs and larvae live where? | In the environment |
Nematode larvae and adults live where? | In humans |
What is the common name for Enterobius vermicularis? | Pinworm |
What is the route of transmission for Enterobiasis/pinworm? | Human-to-human or environmental |
In what patient population is Enterobiasis/pinworm most commonly a problem? | Pediatrics |
What is the most significant clinical feature of Enterobiasis/pinworm infection? | Perianal pruritis |
What diagnosis technique and collection technique is used to diagnose Enterobiasis/pinworm? | Eggs detected on perianal skin; Cellophane/Scotch tape can be used to collect worms |
Which two nematode species are transmitted via soil ingestion? | Ascaris lumbricoides (Ascariasis), and Trichuris trichiura (Trichuriasis) |
Which soil-transmitted nematode has the following life cycle: ingested eggs- larva hatch in small intestine- carried to liver- larva migrate to heart- then to alveolar sacs of lungs- then up trachea- swallowed- adults develop in sm. intes- penetrate/block | Ascaris lumbricoides/Large intestine roundworm |
Which soil-transmitted nematode has the following life cycle: ingested eggs- larva hatch in small intestine- migrate to colon- adults mature in colon- cause prolapsed colon? | Trichuris trichiura/Whipworm |
What is the common name for Ascaris lumbricoides? | Large intestine roundworm |
What is the common name for Trichuris trichiura? | Whipworm: adults look like a whip |
Which soil-transmitted organism can cause Loeffler's syndrome? | Ascaris lumbricoides/Large intestine roundworm |
Which soil-transmitted organism may have colon-related symptoms of pain, diarrhea, irritation, or rectal prolapse covered with worms? | Trichuris trichiura/Whipworm |
What nematodes penetrate the skin? | Hookworms and Strongyloides stercoralis |
What clinical signs are seen with hookworms? | Continual blood loss. Others depend on host nutrition |
What clinical signs are seen with Strongyloidiasis? | Malabsorption, hyperinfection if immunocompromised |
What diagnostic strategies are used to diagnose hookworm or Strongyloides infection? | Detect hookworm eggs or Strongyloides larvae in the feces |
What is the first intermediate host of Trematodes? | Snails |
Which nematode has a flattened, leaf-like body, is hermaphroditic, and has oral and ventral suckers? | Trematode |
What is the common name for Clonorchis sinensis? | Chinese liver fluke |
How is Clonorchis, the Chinese liver fluke, commonly transmitted? | From raw, smoked, pickled, salt-cured, and dried fish |
Where in the human body does Clonorchis, the Chinese liver fluke live? | Biliary ducts |
Which 3 types of worms migrate up the trachea, and are swallowed to infest the small intestine? | Ascaria lumbricoides (Large intestinal roundworm), hookworms, and Strongyloides stercoralis |
What cancer is commonly associated with chronic Clonorchiasis (Chinese liver fluke) infection? | Cholangiocarcinoma |
What diagnostic strategies are used for Clonorchiasis (Chinese liver fluke)? | Liver disease, geographic history, eggs in feces |
Which tapeworm is commonly found in pork? | Taenia solium |
Which tapeworm is commonly found in beef? | Taenia saginata |
What clinical characteristics may be seen with Taenia (tapeworm) infections? | Cysticercosis: blindness, seizures |
What diagnostic strategies are used for Taenia (tapeworm) infections? | Proglottids/eggs in feces |
What is the common name for Diphyllobothrium latum? | Fish tapeworm |
Which tapeworm is considered a zoonosis? | Diphyllobothrium latum (Fish tapeworm... occurs in many fish-eating mammals worldwide) |
Which tapeworm has an avidity for Vitamin B12, but does not often cause megaloblastic anemia? | Diphyllobothrium latum (Fish tapeworm) |
Which diagnostic strategies are used for Diphyllobothrium latum (fish tapeworm)? | Possible megaloblastic anemia with dietary history, and eggs in feces |
Nasal discharge/obstruction, sneezing, cough malaise, throat discomfort for 2-4 days, and no fever likely indicate what condition? | The cold (Acute Respiratory Disease) |
A patient is diagnosed with the cold (Acute Respiratory Disease). What information is important to tell the patient about their treatment? | Infection is usually benign and self-limited. Treatment will be symptomatic |
Which intranasal treatment has been advised against for use in treating the cold/ARD? | Zicam/ intranasal zinc remedies ("Cold-Eeze") |
What 3 infectious agents are common causes of the cold/ARD? | Adenovirus (+unknown viruses = 30=40%), Rhinovirus (25%), Coronavirus (10%) |
What season are Rhinoviruses most common? | Winter |
What is the major vector for transmission of Rhinoviruses? | Hands: person-to-person contact |
What is the best technique for controlling spread of Rhinovirus? | Hand washing and disinfecting objects |
What new medication is effective in halting Rhinovirus infection, but has not been approved for mass use yet? | Picovir (Pleconaril) |
What is the defining feature to differentiate Influenza serotypes A, B, and C? | Nucleocapsid proteins |
Which Influenza serotype is the worst? | Type A |
Which Influenza serotype is a cause of epidemics and its seriousness should not be over-looked? | Type B |
What membrane component of Influenza viruses allow for attachment to a host cell? | H hemagglutinin |
What membrane component of Influenza viruses allow for viral penetration and release from infected cells? | N neuraminidase |
A patient presents with an abrupt onset (after a 1-2 day incubation period) of fever, aches, chills, and a cough that will persist for about 1 week . What might be the cause for this? | Influenza infection |
What is the biggest worry with Influenza infection? | Complications... RELAPSE. |
What are 4 worrisome complications associated with Influenza infection? | Primary influenza viral pneumonia; Secondary bacterial pneumonia by Strep. pneumoniae, Staph. aureus, or Haemophilus influenza type B; Reyes Syndrome, Guillain Barre Syndrome (demyelination) |
What 3 diagnostic techniques are used for Influenza? | Clinical findings if in an epidemic situation, otherwise: viral isolation from throat nasopharyngeal swab, or rapid test kit for influenza virus antigens (False negatives occur especially early in course when antigen levels may be low) |
What 2 medications are available to stop Type A influenza virus only as prophylaxis in immuno-deficient/compromised patients? | Amantadine and Rimantadine |
What 2 medications are available to stop Type A and B influenza viruses? | Oseltamivir and Zanamivir |
What mechanism of viral proliferation do Amantadine and Rimantadine, Type A influenza viral targets, inhibit? | Viral uncoating and penetration |
What mechanism of viral proliferation do Oseltamivir and Zanamivir, Type A and B influenza viral targets, inhibit? | Spreading/Release of virus |
What is the seasonal influenza virus usually formulated with? | 2 most prevalent Type A viruses, and the most prevalent Type B virus |
When are Influenza vaccines typically administered? | Fall/October, before the typical flu season begins |
What 7 population groups are targeted for Influenza vaccines? | CARE GIVERS. 65+. Nursing home residents/chronic care housing facilities. Adults/Children with chronic lung/Cardiovascular disorders. Kids with asthma. Adults/Kids with debilitating chronic diseases/immunosuppression. Peds on aspirin (Reyes risk) |
What are the two causes for influenza antigenic variation? | Antigenic drift and antigenic shift |
What is the difference between antigenic drift and antigenic shift in influenza viruses? | Antigenic drift describes a point mutation in influenza H or N proteins, producing only minor variation. Antigenic shift involves recombination, which shift the entire genome of H or N genes. |
Which influenza antigenic variation type are the most severe, and allow for pandemics to occur? | Antigenic shifts: H or N genes undergo recombination |
What season is Influenza most common in? | Winter |
What form of Chlamydiae is the infectious, non-growing form responsible for dispersal? | Elementary Body (EB) |
What form of Chlamydiae is the growing/vegetative form? | Reticulate Body (RB) |
What is the most causative organism of infant pneumonia? | Chlamydiae trachomatis, from infected mother |
What is the causative organism of bronchitis, pneumonia, and sinusitis that is also associated with atherosclerosis? | Chlamydiae pneumoniae |
Which Giardia lamblia stage is the feeding/vegetative state, tear-drop shaped, is dorsoventrally flattened, has 2 nuclei, and acts as an adhesive disc? | Trophozoite |
Which Giardia lamblia stage is environmentally resistant, infectious, oval-shaped, has a hyaline appearance due to a chitin cyst wall, and has 2-4 nuclei? | Cyst |
Which Giardia lamblia stage is ingested? | Cyst |
Where in the human body does the Giardia lamblia trophozoite reside? | Duodenum to feed on epithelial mucous secretions |
How many trophozoites does 1 Giardia lamblia cyst produce?" | 2 |
An 8 year old child presents with intermittent, watery, non-bloody diarrhea and abdominal cramps that have persisted for several weeks. Abdomen is slightly distended. What is the likely diagnosis? | Giardia lamblia |
How many cysts must be ingested for Giardia lamblia infection to occur? | 100 |
If children infected with Giardia lamblia don't present with diarrhea/flatulence/intestinal pain/steatorrhea (fatty stool) = asymptomatic, what is another concern? | Malabsorption/Vitamin B12 deficiency |
Which human immunity cell type/antibody is giardiacidal? | IgA **Human milk |
How is Giardia lamblia most likely transmitted? | Waterborne transmission, fecal contamination, beaver fecal contamination |
In what age group is Giardia lamblia most prevalent? | Children |
What is the definitive diagnostic technique for Giardia lamblia? | GSA (Giardia-specific antigen). Also, multiple stool samples, but that is slow and unreliable since presence of trophs/cysts in stool is dependent upon intermittent viral shedding. |
What are 3 potential treatments for Giardia lamblia? | Tinidazole, Albendazole (DOC, few S/E in kids), Metronidazole (DOC) |
Which stage of Entamoeba histolytica has 1 nucleus and a central endosome? | Troph |
Which stage of Entamoeba histolytica is round/oval in shape, has 4 nuclei, and a blunt chromatoidal bar? | Cyst |
Which life cycle stage is the infective stage of Entamoeba histolytica? | Cyst |
Where does the Entamoeba histolytica troph reside in humans? | Colon, caecum, or extraintestinal/liver. |
A stool sample from a patient with diarrhea shows a cell with RBCs inside. What is the most likely causative organism? | Entamoeba histolytica |
A patient is hospitalized for RUQ pain, a low-grade fever that has persisted for 6 months, and bouts of bloody diarrhea. What is the most likely diagnosis? | Entamoeba histolytica |
Why does Entamoeba histolytica require serious medical attention? | It can cause death due to peritonitis (gut perforation), cardiac failure, and exhastion, intestinal ulcers, and liver abscesses |
What is the route of transmission of Entamoeba histolytica? | Fecal contamination, water and foodborne, flies |
What diagnostic techniques are used for diagnosing Entamoeba histolytica? | Positive ELISA test, amoeba in stool with 4 nuclei, acid-fast positive, CT scan might reveal a 3 cm cyst-like structure/possible liver abscess |
What is the treatment for Entamoeba histolytica? | Albendazole + iodoquinol or Metronidazole + iodoquinol |
What non-invasive parasite looks similar to Entamoeba histolytica? | Entamoeba dispar |
Which 2 causative organisms present diarrhea, fever, malaise, and is self-limiting, but serious in immunocompromised individuals? | Cryptosporidium parvum and C. hominis |
What is the DOC for Cryptosporidium infection? | Nitazoxanide |
What is the route of transmission of Cryptosporidium? | Person-to-person/fecal, contaminated water |
What causative organism would cause diarrhea, cramps, low-grade fever, and are seen as large, acid-fast, autofluorescing, oocysts? | Cyclospora cayetanensis |
What are 5 potential causative organisms of otitis/sinusitis? | Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae |
What is the common causative organism of Streptococcus pharyngitis? | Streptococcus pyogenes |
What is the causative organism of Diptheria? | Corynebacterium diphtheriae |
What is the causative organism of whooping cough? | Bordetella pertussis |
What are 4 predisposing factors of otitis externa? | Moisture (swimmer's ear), insertion of foreign objects, trauma, and chronic skin diseases |
What are to 2 most common causative organisms of otitis externa? | Pseudomonas aeruginosa and Staphylococcus aureus |
A patient presents with otalgia and otorrhea. Upon culture, the bacteria is a gram-negative bacilli that produces non-fluorescent blue pigment (Polycyanin), and fluorescent green pigment (Polyverdin). What is the likely causative organism? | Pseudomonas auruginosa...Otitis externa. **Wood's lamp = fluorescence glows |
A patient presents with otalgia and otorrhea. Upon culture, the bacteria is a gram positive cocci in clusters, is coagulase positive, and Beta hemolytic. What is the likely causative organism? | Staphylococcus aureus...Otitis externa |
When would you given oral antibiotics rather than topical for otitis externa? | If fever is present |
What are the 3 most common causative organisms, in order, of otitis media and sinusitis? | Strep. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis |
A patient presents with fluid/pus behind the tympanic membrane or sinus inflammation. A culture reveals a gram-positive, lancet-shaped diplococci, encapsulated, and is alpha-hemolytic. What is the causative organism? | Streptococcus pneumoniae |
A patient presents with fluid/pus behind the tympanic membrane or sinus inflamation. A culture reveals a gram-negative coccobacilli. What is the causative organism? | Haemophilus influenzae |
A patient presents with fluid/pus behind the tympanic membrane or sinus inflamation. A culture reveals a gram-negative diplococci that is oxidase positive. What is the causative organism? | Moraxella catarrhalis |
A patient presens with fever, sore throat, difficulty swallowing, patchy gray-white tonsilar exudates, enlarged cervical lymph nodes. Culture reveals a G- streptococci that is Beta hemolytic and catalase negative. What is the causative organism? | Streptococcus pyogenes... Streptococcal pharyngitis |
What are the 4 virulence factors of Streptococcus pyogenes? | Capsule, M protein, Lipotechoic acid, and extracellular toxins/enzymes |
What 2 post-infectious sequelae associated with Streptococcus pharyngitis? | Rheumatic fever (self-limiting arthritis and heart valve damage), acute glomerulonephritis |
During what season is strep throat most prevalent? | Winter-spring |
A patient has sudden malaise, low-grade fever, exudative pharyngitis, lymphadenitis, a thick gray-black pseudomembrane, a non-healing ulcer & possibly bull neck. Culture shows G+ pleomorphic bacilli, club-shaped/Chinese letters. What is the organism? | Corynebacterium diphtheriae |
A culture has Gram positive pleomorphic bacilli that are club-shaped and have metachromatic granules. What is the likely organism? | Corynebacterium diphtheriae |
What 3 culture mediums are used to diagnose Corynebacterium diphtheriae? | Blood agar (to rule out hemolytic streptococcus), Loeffler's medium, and cysteine-tellurite (diphtheria grows as black colonies) |
What is the treatment for diphtheria? | Obtain diphtheria antitoxin from CDC to neutralize exotoxin; treat with antibiotics: penicillin or erythromycin |
What are the 6 Pertussis virulence factors? | Adhesins: filamentous hemagglutin (attached to epithelial cells), agglutinogens (attach to host cells). Exotoxins: Pertussis, adenyate cyclase, dermonecrotic, and tracheal |
Which stage of pertussis has inflammation of mucous membranes and presents with nasal congestion, a runny nose, sore throat, low-grade/no fever, and a non-productive cough for 1-2 weeks? | Catarrhal stage |
During which stage of pertussis are patients highly contagious? | Catarrhal stage |
Which stage of pertussis has coughing attacks/spasms... a paroxysmal cough with a whooping sound, lasting 1-2 minutes up to 50x/day, often followed by vomiting? | Paroxysmal stage |
What is the theory behind the whoop sound in the paroxysmal stage of pertussis? | Epithelial cells are extruded = prevents mucous clearance = excess mucous causes airway restriction |
Which stage of pertussis has a decreased number and severity of paroxysmal coughs over 3-4 weeks? | Convalescent stage/recovery |
What are 11 complications associated with the paroxysmal/whooping cough stage of pertussis? | Dehydration, weight loss, insomnia, subconjunctival hemorrhage, petechiae, hernias, rectal prolapse, urinary incontinence, rib fx, pneumothorax, and subdural hematoma |
What are 4 secondary complications possible during the convalescent/recovery stage of pertussis? | Pneumonia, encephalopathy, seizures, and death |
What definitive diagnostic techniques are used for pertussis? | Culture on Bordet-Gengou medium, PCR |
A 6-18 month old patient presents with a fever, hoarseness, a barking cough, rhinitis, sore throat, and SOB. What is a likely diagnosis? | Croup by Parainfluenza virus |
Which agent is a paramyxovirus with 4 known serotypes, enveloped, nonsegmented, ssRNA? | Parainfluenza virus |
What is the physiological explanation behind the barking cough heard with croup? | The inflammatory response to infection causes tracheal constriction (STEEPLE SIGN) below the vocal cords |
What is the MOST COMMON cause of croup? | Infection by Type 1 parainfluenza virus |
What season has the highest cases of croup? | Fall-Winter |
What are 2 complications seen with croup? | Otitis media, Parotitis |
What 2 diagnostic techniques are used for croup? | Direct FAB test, and viral isolation from throat swab |
What is the treatment for croup? | Supportive |
A patient presents with a cough, dyspnea, cyanosis, and sometimes croup. What is the likely causative organism? | Respiratory Syncytical Virus |
What diagnostic tecnhiques are available for Respiratory Syncytical Virus? | Rapid antigen tests, immunofluorescence assay |
What treatment is available for high-risk Respiratory Syncytical Virus? | Monoclonal immune globin (Palivizumab) |
What is the most common causative agent of lower respiratory tract infections in children younger than 4? | Respiratory Syncytical Virus |
When is the worst time of year to be born in reference to Respiraory Syncytical Virus? | 3-4 months prior to RSV season (winter) |
A patient presents with sudden onset of a high fever (>103*F), shaking chills, a productive cough with green-yellow-brown sputum, pleurisy, chest pain, SOB, and consolidation on CXR with well-defined densities. What might the diagnosis be? | Typical Bacterial Pneumonia |
A patient presents with a gradual onset of a low fever (<103*F), non-productive/paroxysmal cough, HA, body aches, joint pain, abdominal pain, and patchy infiltrates on CXR. What might the diagnosis be? | Atypical Bacterial Pneumonia |
What 3 organisms are prevalent in causing pneumonia in patients with no known predisposing factors? | Mycoplasma, Streptococcus, Chlamydophilia |
What 2 organisms are prevalent in causing pneumonia in alcoholic patients? | Streptococcus, Klebsiella |
What 4 organisms are prevalent in causing pneumonia in patients with underlying disease? | Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus |
What 2 organisms are prevalent in causing pneumonia in patients requiring ventilation? | Klebsiella pneumonia or Pseudomonas aeruginosa |
What organism is prevalent in causing pneumonia in patients with travel/job exposure? | Legionella pneumophilia |
What are the microbiological lab test results for Strep. pneumoniae? | G+ lancet-shaped diplococcus, encapsulated if virulent, and alpha hemolysis |
What is the most common causative organism of community acquired pneumonia? | Strep. pneumoniae |
What is the common entry mechanism of S. pneumoniae into the respiratory tract? | Aspiration |
What are the microbiological lab test results for H. influenzae? | G- short bacillus with Lipo-Oligosaccharide and fimbriae |
Which strain of H. influenzae is responsible for pneumonia? | Nonencapsulated/ nontypable |
What part of the respiratory tract, specifically, does H. influenzae reside as normal flora? | Mucous membranes |
What 4 conditions in patients are at high risk for H. influenzae infection? | Debilitated hosts: asthmatics, COPD, smokers, or immunocompromised |
What diagnostic techniques are used for H. influenzae? | CXR (patchy infiltrates), signs/symptoms, and Gram stain results |
Which pnemonia-causing bacteria is the smallest of the free-living bacteria, is pleiomorphic in shape, lacks a cell wall, contains sterols in the membrane and has a "fried egg" appearance? | Mycoplasma pneumoniae |
Which organism is the most common cause for atypical pneumonia? | M. pneumoniae |
What is released by M. pneumoniae to cause epithelial damage and ciliostasis? | H2O2 and O2 radicals |
What 2 diagnostic techniques are helpful for M. pneumoniae? | CXR (interstitial, patchy infiltrates),Serology |
What is the DOC for M. pneumoniae? | Azithromycin |
Which pneumonia-causing bacteria are very tiny, non-motile, coccoid-shaped, G-, obligate intracellular parasites that are found within intracytoplasmic inclusions? | Chlamydophilia pneumoniae |
Which pneumonia-causing bacteria replicate by entering the cell as an elementary body, reorganizing into a reticulate body, multiplying by binary fission, condense back into elementary bodies, & cause cell lysis to release themselves into the environment? | Chlamydophilia pneumoniae |
What diagnostic technique is used for Chlamydophilia pneumoniae? | Serology |
What is the DOC for Chlamydophilia pneumoniae? | Doxycycline |
A thin, pleomorphic, G- bacillus with fimbriae, a single, polar flagellum that produces Beta-lactamase, and is catalase and oxidase positive is likely which organism? | Legionella pneumophilia |
What is the mechanism of inoculation in humans by Legionella pneumophilia? | Associated with water; Inhale aerosols: bacteria then survive intracellularly |
What 2 conditions is Legionella pneumophilia known to cause? | Pontiac fever and Legionnaires' Disease |
A patient with fever, chills, malaise, myalgia, headache, and no sign of pneumonia has been confirmed to be infected with Legionella pneumophilia. What is the diagnosis/disease? | Pontiac fever = self-limiting |
A patient with abrupt onset of fever, chills, a dry/non-productive cough, HA, and GI/neurological symptoms is confirmed to be infected with Legionella pneumophilia. What is the diagnosis? | Legionnaires' Disease |
Where does Legionella pneumophilia survive out in nature? | In protozoans |
What is the gold standard for Legionella pneumophilia diagnosis? | Culture |
What is the DOC for Legionella pneumophilia treatment? | Levofloxacin |
Which gram negative encapsulated bacillus causes an aggressive necrotizing, community-acquired, lobar (commonly upper lobe pneumonia), inoculated by aspiration? | Klebsiella pneumoniae |
A patient presents with acute high fever, chills, flu-like symptoms, a productive cough with thick, blood-tinged "currant jelly" sputum, and pleuritic chest pain. What is a likely causative organism? | Klebsiella pneumoniae |
What 3 patient populations are at risk for Klebsiella pneumoniae infection? | Alcoholics, COPD patients, Diabetics |
What is the DOC for Klebsiella pneumoniae? | Aminoglycosides/ Cephalosporins |
A G-, oxidase-positive, aerobic bacilli that has pili, a mucoid capsule, secretes A-B exotoxin, secreted pyocyanin and pyoverdin, and has a fruity odor is isolated from a patient with pneumonia symptoms. What is the organism? | Pseudomonas aeruginosa |
Toxicity from LPS and Endotoxin A, progressive cyanosis, and empyema formation are commonly associated with what pneumonia-causing organism? | Pseudomonas aeruginosa |
Which pneumonia-causing organism is considered normal flora in hospitals? | Pseudomonas aeruginosa |
What is the diagnostic technique for Pseudomonas aeruginosa? | C&S (many strains are drug-resistant) |
A G+, grape-like clustered, Catalse positive, Coagulase positive, Beta lactamase producing organism is isolated from a pneumonia patient. What is the organism? | Staph aureus |
Which pneumonia-causing organism often colonizes after a viral respiratory infection, and can result in abscess formation? | Staph aureus |
What people are the reservoir for Staph aureus? | Nasal carriers |
How does Staph aureus respiratory transmission occur? | Aspiration, hematogenous spread |
What diagnostic techniques are used to confirm Staph aureus as the causative organism of a pneumonia infection? | CXR (abscesses, pneumatoceles, consolidation), C&S (often multi-drug resistant) |
What 3 organisms cause tuberculous mycobacterial infections? | Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium africanum |
What 3 organisms cause non-tuberculous mycobacterial infections? | Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium kansasii |
What are the 4 reasons why TB is so difficult to eradicate? | Patient compliance with long term therapy, antibiotic resistance, co-infection with HIV, and difficulty identifying the organism |
What is the O2 requirements of Mycobacterium tuberculosis? | Obligate aerobe |
Describe the process and results of Acid-staining mycobacterium tuberculosis. | Ziehl-Neelsen/Kinyoun stains are used, causing the acid-fast Mycobacterium tuberculosis to turn red. Auramine/Rhabdamine fluorescent stain can also be used |
Which organisms are obligate aerobes, acid-fast, bacilli/rod-shaped, non-motile, and are heat sensitive/killed by pasteurization? | Mycobacterium tuberculosis |
Which 2 media are specific for Mycobacterium tuberculosis, and what will the colonies look like? | Middlebrooks and Lowenstein-Jensen: colonies are "Ruff, Buff, and Tuff" |
What virulence factor from Mycobacterium tuberculosis inhibits cytokine release (neutrophil migration and damages host cell mitochondria? | Cord factor |
Which virulence factor of Mycobacterium tuberculosis inhibits phagolysome formation, promoting intracellular growth? | Sulfatides |
Which virulence factor of Mycobacterium tuberculosis suppresses T-Cell activity and INF-gamma production? | LAM |
What is the bacterial actions during Primary tuberculosis infection, and what are the clinical signs/symptoms? | M. tuberculosis enter macrophages of alveoli and multiply/lyse macrophages or are carried to lymph nodes = resembles bacterial pneumonia with acute inflammatory reaction and exudative lesions |
Describe the process behind caseous necrosis/tissue destruction with the immune system's attack on Mycobacterium tuberculosis primary infection? | Macrophages present MTB antigens to T-Cells = T-Cells become sensitized = multiply, go to infection, attract/activate macrophages. Macrophages produce lytic enzymes (POI and RNI) |
What Mycobacterium tuberculosis antigens do macrophages present to T-Cells for sensitization? | ESAT-6 and CFP-10 |
What lytic enzymes are produced when macrophages destroy MTB during primary infection? | ROI (Reactive oxygen intermediates) and RNI (Reactive Nitrogen Intermediates) |
What causes the production of lesions in MTB primary infection? | Granulomas/Tubercles (Macrophages + multinucleated giant cells + fibroblasts + collagen fibers) with caseous necrosis coalesce |
Describe the initiation of latent TB in the primary infection stage. | Low-activity MTB cells within granulomas cause low oxygen levels and low pH within. Immune system is content with MTB containment and low activity = ONLY WHEN CELL MEDIATED IMMUNITY (sensitized T-cells/active macrophages) IS EFFECTIVE |
What is the result of ineffective cell-mediated immunity in primary MTC infection? | MTB proliferation continues, lung tissue is destroyed, Miliary tuberculosis: loss of organ/tissue function *Pott's Disease (destruction of vertebral bodies) |
When is a Tuberculin skin test (*PPD, TST, or Mantoux test) able to give a positive reading? | 2-6 weeks after infection |
When is IFN-gamma detection blood tests (QuantiFERON, T-SPOT) able to give a positive reading for MTB? | 2-6 weeks after infection |
Which Mycobacterium species are weakly G+, strongly acid-fast, and ubiquitous (Live in water, ocean, soil, plants, etc.)? | M. avium and M. intracellulare |
What is the leading cause of non-tuberculosis mycobacterium infections? | AIDS |
What is the second leading cause of non-tuberculosis mycobacterium infection? | M. kansasii from tap water |
Lady Windermere's Syndrome is associated with what condition? | Pulmonary MAC (nontuberculosis mycobacterium) |
In what class of mycobacterium infections are the infections always new/never reactivated latent infection? | Non-tuberculosis mycobacterium/ MAC infections |
What symptom is commonly seen with non-tuberculosis mycobacterium, but not with TB? | Diarrhea. Other symptoms: fever, weight loss, night sweats |
When is non-tuberculosis mycobacterium MAC called disseminated MAC (DMAC)? | When granulomas are not effective at containing the infection (esp. with HIV pts), and infection can occur in any tissue/organ = enlargement followed by dysfunction |
What is the difference in treatment for non-tuberculosis mycobacterium-infected HIV patients with MAC infection and without MAC infection? | With MAC: Clarithromycin/ Azithromycin + Ethambutol + Rifabutin. Without MAC: Clarithromycin/ Azithromycin |
In addition to drug therapy, what else might be useful in the treatment of non-tuberculosis mycobacterium? | Surgical excision of lymph nodes/ lobes of lungs |
What 3 symptoms may help to differentiate inflammatory diarrhea from non-inflammatory diarrhea? | Fever, tenesmus, blood |
What organism is commonly associated with Hemolytic Uremic Syndrome? | E. coli O157:H7 **Shiga-toxin-producing |
What are the classic symptoms associated with Shiga-toxin producing E. coli O157:H7? | No fever, bloody stool, abdomen tenderness |
When should diarrhea testing be performed? | With moderate-severe diarrhea/illness, or if inflammatory diarrhea is suspected |
What is the priority in acute diarrhea management? | Rehydration |
What symptomatic treatment options are available for diarrhea? | Loperamide/Imodium (inhibits peristalsis and secretions **not for inflammatory diarrhea), Bismuth subsalicylate (Pepto-Bismol) |
What is the empiric DOC antibiotic for diarrhea and under what conditions is it indicated? | Ciprofloxin when pt is at risk for complications or inflammatory diarrhea without suspicion of enterohemorrhagic E.coli or C. diff infection |
Which diarrhea-causing pathogen is commonly associated with hospitalization and antibiotic use? | C. diff |
What are the 3 most common pathogens for typical pneumonia? | Strep. pneumo, H. influenza, M. cattathalis |
What are the 4 pathogens that commonly cause atypical pneumonia? | Mycoplasm pneumoniae, Chlamydophilia spp., Bordatella pertussis, Legionella |
What is the first line antibiotic choice for community-acquired pneumonia in an otherwise healthy patient? | Macrolides: Azithromycin, Clarithromycin. Or Tetracyclines: Doxycycline |
Which antibiotics are typically used in pneumonia patients with comorbidities such as COPD, drug use, alcoholics? | Respiratory fluoroquinolone: Levofloxacin, Moxifloxacin |
When should a patient with pneumonia be hospitalized? | If they have more than one of the CURB criteria: Confusion, BUN> 19 mg/dL, Respirations >30/min, BP <90/60, Age 65+ |
What is the empiric therapy for hospital-acquired pneumonia? | Varies according to the institution and it's specific pathogens |