Exam VI - Respiratory & Genital Infections Flashcards

Question

Pseudomonas aeruginosa

Answer 1

Gram-negative rod, ubiquitous, capable of growing on many substrates and temperatures ranging 4-42 C, aerobic, and forms a biofilm - Alginate capsule Motile: flagella and pili Opportunistic and nosocomial infections; highly antibiotic resistant Characteristic color and sweet grape like odor Oxidase positive

Answer 2

Risk factors: cystic fibrosis - colonized by S. aureus first then with P.aeruginosa by 5 yrs old - lifelong Burkholderia cepacia is also another lung bacteria that affects those with CF These bacteria cause the immune system to cause the damage (indirectly) Most CF patients die from P. aeruginosa lung associated infections (90%) Research very hard because alginate in P. aeruginosa contributes to the biofilm formation Fresh isolates of P. aeruginosa from CF patients are mucoidy, but in vivo and in vitro switching in the mucoidy phenotype via quorum sensing in culture Hospitalized on ventilation- high risk

Answer 3

Aspiration of respiratory or gastric material Risk factors: dental work and loss of consciousness mixture of Bacteroides and Fusobacterium - necrotizing, lung abscesses, empyema (formation of pus in pleural cavity) ***copious amounts of foul smelling sputum

Answer 4

``` Anthrax Plague Q fever Tularemia Brucellosis ```

Answer 5

Gram positive rods occurring in chains Aerobic, non-motile, forms resistant endospores Spores remain viable for years in soil, dried or processed hides; present in air, water, soil and vegetation Three types: cutaneous, inhalation, and GI Inhalation: capsule (polyglutamic acid capsule (AA)) + anthrax toxin Transmission: inhalation of endospores (spores have no taste or smell) Symptoms: Initial - sore throat, mild fever, myalgia, cough After several days - severe coughing, nausea/vomiting, lethargy, confusion, shock, death

Answer 6

Major virulence factor secreted by B. anthracis Encoded by plasmid pXO1 carrying three toxin genes A/B toxin Three component proteins: Protective antigen (PA) Edema factor (EF) Lethal factor (LF) *these cause tissue damage, edema, and cell death High mortality rate

Answer 7

Diagnosis: microscopy/Gram stain of sputum Treatment: penicillin, doxycycline, ciprofloxacin Vaccine available for military and researchers decontamination is costly and time consuming

Answer 8

Aerobic, acid fast rods, intracellular Cell wall contains mycolic acid, which areresistant to detergents and common antibiotics and provide protection from desiccation Grows very slowly on culture Due to the high lipid content of the cell walls acid-fast bacteria retain the carbolfuchsin and will appear fuchsia

Answer 9

Transmission: inhalation Incubation: 4-12 weeks Virulence: cord factor (not a toxin) causing a characteristic serpentine arrangement due to aggregation of the cells Tissue necrosis is due to immune response (indirect) Symptoms: productive cough (sputum may be bloody), mild fever, fatigue, malaise, weight loss, sweating Risk factors: poor nutrition, drug users, alcoholics, crowded living conditions (prisons), immunocompromised Endemic areas: Southeast Asia, Sub-Saharan Africa, Eastern Europe

Answer 10

1. Primary tuberculosis – initial case of tuberculosis disease 2. Secondary tuberculosis – reactivated tuberculosis 3. Disseminated tuberculosis – tuberculosis involving multiple systems (poor prognosis)

Answer 11

Inhalation of bacteria and then engulfed by alveolar macrophages, but not killed (intracellular) Survive and multiply and attract and activate more macrophages to form tubercle/granulomas to hide from immune system Can remain dormant for years to decades, but immunosuppressed individuals become infected

Answer 12

1. Caseous lesion- cheese-like consistency 2. Ghon complexes -calcified caseous lesion; show up prominently in chest X-rays (in lungs and lymph nodes) 3. Tuberculous cavities- tubercle that has liquefied and formed an air-filled cavity from which bacteria can spread (reactivation and miliary tuberculosis)

Answer 13

Screening: tuberculin skin test, Mantoux test, PPD test (same thing just different names) Intradermal injection of purified protein derivative, then check site in 48-72 hours CMI - cell mediated immunity Positive indicates exposure not an active infection, so must get a chest X-ray to look for signs of tubercles Microscopy sputum, acid fast stain, fluorescent auramine stain, Lowenstein-Jensen agar Grows very slowly -6-8 weeks

Answer 14

MDR-TB: multidrug resistant - resistant to isoniazid and rifampin XDR-TB: extremely drug resistant- resistant to isoniazid, rifampin, and at least one of the 2nd line drugs DOTS: Directly Observed Treatment Short course recommended by the WHO and CDC; ensures patient compliance or jail Treatment: combination therapy of isoniazid and rifampin or ethambutol and pyramindole (RIPE) 6-9 months Potential exposure: isoniazid treatment BCG Vaccine: Bacille Calmette-Guerin Live, attenuated M. bovis not used in the U.S. because screening would not be as cheap as it is now and anyone with suspected TB would need a chest X-ray and other tests

Answer 15

Facultative or strict anaerobic gram positive rod NF of mouth, stomach, GI track, GU tract Can cause opportunistic infections

Answer 16

1. Discharge – watery /milky adherence to the vaginal wall 2. pH – raised 3. Specific tests – Amine test: KOH + vaginal fluid; fishy odor =“Whiff test”; BV – Positive Amine Test 4. Gram stain results – clue cell; gram variable Clue cell: overgrowth of bacteria present; gram negatives and positives; epithelial cells is covered with growth No itchiness, no painful urination; not a lot of discomfort There are no white cells (PMNs); neutrophils; aka your body is not reacting to it and your immune system isn’t activated Very bad odor and vaginal discharge due to putrescine, cadaverine, trimethylamine (product of bacterial metabolism)

Answer 17

Gardnerella vaginalis – most associated Mycoplasmas Anaerobes – Peptostreptococci, Bacteroides spp., and Mobiluncus spp.

Answer 18

``` causative agent of BV Gram-variable bacillus Member of endogenous vaginal flora Major organism associated with BV Culture not really very useful for dxs Seen on gram stain – clue cells Gardnerella has been isolated from sexually inexperienced girls A disturbance of the vaginal microbial ecosystem ```

Answer 19

causative agent of BV Gram stain: no gram stain because no cell wall Cell membrane characteristic: has sterols Why are these characteristics important: cannot treat it with beta lactams because they target the cell wall, which is does not have Other Members of Species: M. genitalium: non-gonococcal urethritis (NGU) and Pelvic Inflammatory Diseases (PID) Ureaplasma urealyticum: NGU, pyelonephritis, spontaneous abortion M. hominis: Pyelonephritis and postpartum fevers

Answer 20

causative agent of BV Obligate anaerobic gram variable curved rod with tapered ends Classified as gram positives: have gram-positive thick cell wall, lack endotoxin, and is susceptible to vancomycin, etc.; doesn't stain well Mobiluncus curtisii Abundant in women with BV Role in pathogenesis vague

Answer 21

Gram positive cocci in chains Beta hemolytic; small zone of hemolysis compared to strep pyogenes Lancefield: group B Capsule: polysaccharide and antibody protective Vaginal colonization: causes bladder infections, premature delivery, prolonged membrane rupture, and postpartum fever Transmitted to infants during birth leading to neonatal disease Can cause neonatal meningitis if capsule present

Answer 22

``` Early onset (<7 days old): bacteremia, pneumonia, meningitis, severe consequences Late onset (1 week to 3 mos.): bacteremia with meningitis if capsule present ```

Answer 23

Second most common vaginal infection in US primary source - endogenous opportunistic pathogens (when taking antibiotics and normal flora decreases allowing its population to grow) Fungal Species: Candida albicans and Candida spp. Three groups of females 1. never had an episode 2. infrequent, isolated episodes 3. repeated, recurrent, chronic infections 75% of women will have at least one episode some are more prone than others

Answer 24

1. Discharge - Cottage cheese appearance, discrete pustulopapular lesions 2. pH – 4.5 3. Specific tests – germ tubes from yeast; grows on Sarbouraud Dextrose agar 4. Gram stain results - positive

Answer 25

chief complaint - itching burning sensation when urinating cervix normal erythema, swelling of labia and vulva Dx: microscopic finding - yeast cells, budding hyphae, few PMN’s (neutrophils) laboratory identification **germ tubes for Candida albicans pseudohyphae on cornmeal agar biochemical tests for other species Grows on routine lab media, but to culture would use ***Sabouraud dextrose agar Tx: hard to treat because they are eukaryotic

Answer 26

``` Esophagitis – HIV/immunocompromised Diaper rash – infants and elderly Thrush – HIV/immunocompromised Nail infections – occupation with hands in water like dishwashers/artificial nails Systemic - immunocompromised ```

Answer 27

anaerobic flagellated protozoan: life cycle is simplest for protozoa; binary fission, no cyst stage requires preformed purines, pyrimidines, fatty acids, and sterols Survives on fomites for approx. 30 minutes - needs human host 1. Discharge - frothy yellowish, green; large amount of discharge 2. pH – 4.7 3. Specific tests – wet prep, see protozoan; large number of PMNs; positive whiff test 4. Gram stain - will NOT show up on a gram stain because not bacteria

Answer 28

At risk: lower socioeconomic populations, multiple sexual partners, previous history of STD, coexistent infection, non-use of barrier or hormonal contraceptives

Answer 29

Vaginitis, urethritis Chief complaint – frothy yellowish, green discharge Strawberry cervix - localized hemorrhages on cervix and vagina (dark spots) Other signs/symptoms: bad odor, vulvar pruritus (itching), dysuria (painful urination) Vaginal soreness, dyspareunia (pain during sex) Males - slight urethral discharge control depends on treating partners: evaluate for other STD’s and evaluate for candidiasis, BV

Answer 30

Cervicitis: most common STD syndrome Often “Silent partner” to male urethritis Inflammation of columnar and subepithelium of endocervix is greatest in adolescent girls so they are very susceptible compared to older women Cervicitis and Urethritis: up to 70% of women are asymptomatic Serves as reservoir Dysuria, vaginal discharge, vaginal pruritus (itching and discharge) Mucopurulent watery discharge Easily induced bleeding of the cervix

Answer 31

Neisseria gonorrhoeae- pathogenic Neisseria meningitides - pathogenic Neisseria species- normal flora and non-pathogenic Gram negative diplococci/ kidney bean shaped Neisseria gonorrhea - have many PMNs Capnophilic- thrive in high CO2 environment Growth on routine media N. gonorroheae- chocolate agar but not blood agar N. meningitidis- both chocolate agar and blood agar All oxidase positive N. gonorrhoeae – glucose only N. meningitidis – glucose + maltose

Answer 32

Pili - attachment to non-cilated epithelial mucosal cells, resist phagocytosis by neutrophils, and antigenic variation to hide from immune system Por protein: PorA- silent in N. gonorrhoeae but on in N. meningitidis PorB- on in both Neisseria gonorrhoeae and meningitidis, must be functionally active, antigenic variation, prevents phagolysosomal fusion Transferrin-binding proteins (also lactoferrin BPs)- acquisition of iron for growth restricting hosts to humans LOS- like LPS, but oligosaccharide (shorter); still has Lipid A portion serving as the endotoxin causing pelvic inflammatory disease IgA protease Beta lactamase

Answer 33

acute urethritis, proctitis, pharyngitis, ophthalmia neonatorum, acute cervicitis or vulvovaginitis Epidemiology: US higher than most other developing countries Poverty, inner city African-American Multiple sex partners, recent new partner females more affected than males; females = reservoir

Answer 34

1. Discharge - mucourulent, creamy yellow discharge 2. Gram stain results – negative in pairs within PMNs 3. Other tests – NA amplification, oxidase positive, and glucose oxidized 4. Signs and symptoms & Complications- Sterility from complications adhere to stratified columnar epithelial cells penetrate to subepithelial connective tissue and multiply severe acute inflammatory response

Answer 35

Males: from anterior to posterior urethra and Cowper’s glands; fibrosis - urethral strictures; prostatitis, epididymitis; permanent sterility may develop Females: burning and frequency of urination, mucopurulent discharge, fever and abdominal pain from primary foci to fallopian tubes, pelvic peritoneum salpingitis, tubo-ovarian abcesses,PID permanent sterility or ectopic pregnancy may result

Answer 36

Sometimes the infection gets into the blood and spreads throughout the body about 1% of male or female patients, usually w/ asym. genital infection, septicemia LOS toxicity - chills, fever, malaise, petechial skin lesions Migratory arthralgia, suppurative arthritis of wrists, knees, ankles, pustular rash on erythematous base on extremities but NOT on head/trunk Dx: male urethral exudate - gram stain females - culture and ID other sites males, females - culture and ID

Answer 37

inoculate immediately onto appropriate media Thayer Martin, NYC media Transgrow, Jembec Plate does NOT grow on blood agar, only on chocolate atmosphere (enriched CO2) and temperature important Nucleic acid amplification assay: test for Gonorrhoea and Chlamydia both Culture Media: chocolate agar, Thayer-Martin agar, NYC medium Biochemical testing: glucose oxidized

Answer 38

ceftriaxone single dose treat w/doxcycline for co-infection w/Chlamydia neonates - drops at birth required by law 0.5% erythromycin 1% tetracycline or 1% silver nitrate (won’t effect Chlamydia)

Answer 39

obligate intracellular bacterium cell wall lacks peptidoglycan life cycle contains elementary bodies, reticulate bodies require source of ATP from host; will not grow on culture Elementary Bodies: Infectious form, cannot replicate, bind to receptors on host cells, metabolically inactive Reticulate Bodies: Metabolically active form, replicating form, non-infectious form

Answer 40

Chlamydophila pneumoniae Chlamydophila psittaci Chlamydia trachomatis

Answer 41

A, B, Ba, C – Endemic trachoma- eye infection that can lead to blindness is untreated; discharge B, D-K – Genitourinary disease; discharge L1, L2, L3 – Lymphogranuloma venereum; ulcerative

Answer 42

Most prevalent STD in US, many are co-infected w/gonorrhea, only source is humans Other infections: pharyngitis, conjunctivitis, PID (pelvic inflammatory disease), perihepatitis 1. Discharge – scant and watery 2. Gram stain results – PMNs with no gram stain 3. Other tests – NA amplification 4. Signs and symptoms: infection asymptomatic initially host develops acute inflammatory response - PMN’s “watery” discharge

Answer 43

Most are symptomatic Reiter syndrome: urethritis, conjunctivitis, polyarthritis, mucocutaneous lesions, EB found in specimens with arthritis caused by chlamydia

Answer 44

males - disseminate into epididymis - epididymitis female - travel up fallopian tubes into peritoneal cavity - salpingitis, PID newborns – mucopurulent conjunctivitis 1-2 wks after delivery; pneumonia, pneumonitis

Answer 45

``` Most serious – salpingitis Range from silent infection to severe Fever, lower abdominal pain, tenderness of uterus, adnexae (structures related to the uterus) Severe inflammatory response caused by chlamydia ```

Answer 46

Fluorescent antibody staining of genital specimens, conjunctival scrapings Culture – most specific and requires tissue culture can do ELISA, genetic probes Nucleic acid amplification test

Answer 47

caused by Chlamydia trachomatis (not the same as genital chlamydia); L serovars cause Rare in US, common in developing countries STD, often co-infection Would be in differential for ulcer diseases People who travel out of the country are more likely Dx: cannot gram stain chlamydia so use NAAT, serology Isolation of Chlamydia from infected tissues, secretions

Answer 48

Ulcerative: Granuloma inguinale, Chancroid, Syphilis, LGV (covered with chlamydia) Mucopurulent: Chlamydia, Gonorrhea, Trichomonas

Answer 49

Painless: Syphilis, LGV, granuloma inguinale, Painful: Chancroid, HSV

Answer 50

Primary lesion- generally painless papule that ulcerates, non-indurated herpetiform ulcer Secondary stage - acute lymphadenitis with bubo formation (painful), acute hemorrhagic proctitis following rectal intercourse, fever, other symptoms of systemic infection Tertiary stage - rare Development of genital ulcers, fistulas, rectal strictures, genital elephantiasis – result of inflammatory response

Answer 51

Disease - Granuloma inguinale aka Donovania granulomatis until recently Causative agent: gram-negative rod Pathognomonic feature: Donovan bodies - vacuole w/i PMN or plasma cell where organism multiplies

Answer 52

Four classic forms of presentation 1. ulcerogranulomatous 2. hypertrophic or verrucous (cauliflower growth) 3. necrotic – foul smelling ulcer 4. sclerotic – formation of fibrous and scar tissue; walled off and thick Firm subcutaneous nodule progresses to beefy-red, granulomatous heaped ulcer, ulcers generally painless multiple lesions form; bleed on contact

Answer 53

Carcinoma - esp. with advanced lesions Syphilis - condylomata lata Large herpetic ulcers Amebiasis

Answer 54

Chancroid: aka soft chancre caused by Haemophilus ducreyi; predominantly male disease; has irregular border Haemophilus ducreyi: gram negative rod with“school of fish” appearance Reservoir: genital tract of humans Culture: requires specific media, requires X factor only Oxidase positive (like gonorrhea and aeruginosa)

Answer 55

Small erythematous papule, not painful initially Patients seek attention after having ulcers from 3-5 weeks since it is painful at that point Range from 1-4 ulcers typically Very painful, friable ulcer with ragged borders develops Ulcer base may be covered with yellow or grey necrotic purulent exudate Lymphadenopathy from spread to inguinal lymph nodes may rupture, exudates highly contagious

Answer 56

Definite – isolation of H. ducreyi from lesion Probable – clinical findings compatible, negative darkfield, negative syphilis serology, negative HSV culture Epidemiology: Probably underreported, mostly minority populations, African-American, Hispanics, Heterosexuals Female prostitutes and clients

Answer 57

Ulcer description: hard chancre, indurated, well circumscribed; painless; regular border spirochete- thin and cannot gram stain so use silver stain or darkfield microscopy (+ = disease) corkscrew type motility with axial filaments Bundles of periplasmic flagella cannot culture on artificial media Lack TCA cycle – need host to survive Sensitive to oxygen

Answer 58

sexual contact - abraded skin or mucous membranes oral, anal sex congenital secondary disease w/latent infection Primary, secondary, tertiary, latent, and neonatal phases

Answer 59

Men having sex with other men are at high risk Located at site of inoculation 3 weeks incubation Chancre (hard): painless, indurated, well circumscribed ulcer Regional lymphadenopathy Heal in 1-6 weeks

Answer 60

``` Enter blood from infected foci Flu-like symptoms Disseminated rash few days later Highly infectious Resolves spontaneously within few weeks ``` ``` Rash: Unique – found on soles of feet, palms of hands May be over entire body, in mouth Copper penny macules or papules Resolves on own within a few weeks Patient has then entered latent stage ```

Answer 61

Generalized lymphadenopathy (large lymph nodes) Generalized maculopapular rash Condyloma lata - soft, fleshy papules in genital region Moth-eaten alopecia (chunks of hair falls out)

Answer 62

3 weeks to 3 mos. after secondary stage Early latent - 1 year duration Can transmit to fetus May last 3 to 30 years

Answer 63

Waning of immunity - w/i mos. to 50 yrs. later Treponemes invade CNS, CV system, eye, skin, other internal organs Delayed Type Hypersensitivity reaction or reaction to invasive properties At this point the organism is no longer responsible, but the immune system attacks Transmission does not occur Congenital transmission rare

Answer 64

Destruction of brain parenchyma (paresis) - dementia dorsal roots of spinal cord (tabes) Tabes dorsalis – demyelination of posterior columns of dorsal columns and dorsal roots or both (taboparesis) Meningitis – classic aseptic optic atrophy meningovascular damage Cardiovascular Symptoms: thoracic aortic aneurysm aortitis, aortic endocarditis, on x-ray see ascending aortic calcifications Skin Manifestations: Gummas =destructive, granulomatous, non-progressive lesions treponemes rarely found in the lesions In bones, skin, other tissues

Answer 65

higher prevalence of recurrent secondary syphilis | more rapid progression to CNS

Answer 66

Sequelae: latent infections, multiorgan malformations, death of fetus Majority: born without clinical evidence, but shows up shortly after birth Early (birth to age 2): Extensive cutaneous lesions, rhinitis or “snuffles”, teeth, bone malformations, anemia, hepatosplenomegaly, CNS disease Late: interstitial keratitis, 8th nerve deafness, notched and spaced incisors (Hutchinsons incisors), “raspberry molars”, sabre shins, saddle nose, cutaneous gummas (granulomas)

Answer 67

darkfield microscopy nontreponemal tests - RPR, VDRL treponemal test - FTA-ABS, MHA-TP CSF (acquired and congenital neurosyphilis) -VDRL increased cell count, elevated total protein

Answer 68

They are general screening procedures for syphilis RPR (Rapid Plasma Reagin)/circle card test – positive if agglutination; many other things that can give positives; quick and easy to do and cheap **if positive you would have to confirm them VDRL – Venereal Disease Research Laboratory: slide flocculation test Test for cardiolipin- in mitochondrial membrane because the spirochete will destroy cells IgG or IgM Some false negative False positives: autoimmune diseases; Esp. disem. LE Can use for early syphilis cure following therapy

Answer 69

for syphilis Utilize as antigen T. pallidum subsp. pallidum Fluorescent or microhemagglutination Measure IgG or IgM Positive – not an indication of active disease because positive test could signify someone who had the disease in the past Cannot use to monitor therapy Specificity 99% False +: AIDS, HIV+, Pregnant females, Narcotic addicts, Lyme disease, Neonate of infected mother

Answer 70

``` Penicillin – any stage IM benzathine penicilllin G Some recommend 2 or 3 doses 1 week apart Penicillin allergic – doxycycline or tetracycline reportable, trace contacts ```

Exam VI - Respiratory & Genital Infections Flashcards

(94 cards)