1、Board Review,Paul OKeefe April 16, 2003,Skin/Soft Tissue Infections,Impetigo Cellulitis Fasciitis,Impetigo,Group A streptococcus, Staphylococcus arueus Superficial blistershoney colored crusts on erythematous base No systemic signs Mainly in children May be associated with glomerulonephritis Treat w
2、ith penicillin/antistaphylococcal penicillin,Cellulitis,Deeper infection usually involving skin and subcutaneous tissue Erythema, pain and swelling often with distinct border (erysipelas) Fever and lymphangitis or adenitis common Gp A streptococcus, Staphylococcus aureus most common Treat with antis
3、taphylococcal penicillin unless culture positive,Necrotizing Fasciitis,Streptococcal gangrene (Gp A strept) Deeper infection involving fascia and often muscle Extreme toxicity and rapid spread (“flesh-eating virus”) May have associated toxic shock Treatment surgical removal of necrotic tissue and an
4、tibiotics Penicillin and clinidamycin,Staphylococcus aureus Coagulase negative staphylococcus Streptococcus pyogenes Sterptococcus pneumoniae Enterococcus faecalis,A three year old boy presents with an itchy rash that is spreading. Afebrile with numerous cursted lesions in erythematous base involvin
5、g left shoulder and upper chest and back with few lesions in the right thigh. Culture growing gram positive coccus, beta hemolytic on SBA, catalase negative, inhibited by bacitracin disc. The isolated agent is,A 13 year old develops high fever and a severely painful red rash on the right arm beginni
6、ng at the site of a minor laceration. He has high fever, hypo- tension and extreme toxicity. The arm is red, very swollen, firm and there are areas of black discolor- ation of the skin. The remainder of the skin has a red sunburned appearance. The extreme toxicity is thought to be caused byStreptoly
7、sin O Hyaluronidase M Protein Pyrogenic exotoxin Peptidoglycan,Upper Respiratory Tract Infection,Pharyngitis Sinusitis Otitis media,Pharyngitis,Viral Group A streptococcus (S. pyogenes) Corynebacterium diphtheriae Infectious mononucleosis,Characteristics of Pharyngitis,Pharyngitis and Fatigue,Atypic
8、al lymphocytosis Positive culture for Group A streptococcus Neutrophilia with left shift Low serum globulin Hematuria,A 15 year old presents with fever, sore throat and extreme fatigue. Temperature is 103.2 and there is a yellowish exudate covering both enlarged tonsils. Submandibular, anterior cer-
9、 vical, and posterior cervical lymph nodes are enlarged on both sides. Which of the following is most characteristic of infectious mononucleosis?,Sinusitis,Requires neither X nor V factor for growth Requires X factor but not V factor Requires V factor but not X factor Requires both X and V factors E
10、xuberant growth on sheep blood agar,A 15 yo woman presents with fever, facial pain and severe nasal congestion. She has been suffering with hay fever. CT showed opacification of the R maxillary sinus and an air- fluid level in the left. Gram stain of material obtained by antral puncture disclosed gr
11、am negative coccobacilli. Which of the following characterizes the organism most likely respon- sible for the infection?,Otitis Media,Gp A streptococcus and Gp B streptococcus Neisseria meningitidis and Streptococcus pneumoniae Streptococcus pneumoniae and Haemophilus influenzae Haemophilus parainfl
12、uenzae and Gp A streptococcus Staphylococcus aureus and Gp A streptococcus,A 9 month old child with fever and congestion is diagnosed with right otitis media. Common causes of this infection are?,Community Acquired Pneumonia,Streptococcus pneumoniae Mycoplasma pneumoniae Legionella pneumophila Haemo
13、philus influenzae Chlamydia pneumoniae Tuberculosis,Community acquired pneumonia,A 33 year old male presents with fever and cough 3 weeks after his 7 year old son was treated for pneumonia. X-ray shows a patchy bronchopneumonia involving the right middle and lower lung field. Cold agglutinin test is
14、 positiveWhat is the likely cause?,Features of Community Acquired pneumonia,Communinty Acquired Pneumonia,A 26 year old woman complained of fever, night sweats and cough for 2 months. She had occasional hemoptysis and 15 pound weight loss. Chest x-ray showed fibronodular infiltrates with a cavity in
15、 the posterior segment of the right upper lobe.Please answer the following:What type of isolation would you order? What diagnostic tests would you order?Sputum smear returned positive for AFB.What treatment would you order? Why are multiple drugs necessary for treatment of tuberculosis?,Food Poisoni
16、ng,Infectious Diarrhea,Cause of diarrhea 4 hours after eating fried rice,B. cereus S. aureus Salmonella Shigella C. jejuni Yersinia enterocolitica Vibrio parahemolyticus,Contaminated poultry is the most likely source of,Salmonella Vibrio cholerae Shigella dysenteriae Campylobacter jejuni S. aureus,A
17、n important virulence factor of the organism found on biopsy of the stomach in patients with chornic epigastric pain is,Enterotoxin Polysaccharide capsule Endotoxin Urease Beta-lactamase,Urinary Tract Infection,Penicillin V Erythromycin Trimethoprim/sulfamethosoxazole Gentamicin Clindamycin,A 23 yea
18、r old woman presents with acute dysuria one day after intercourse. Urinalysis discloses 15-20 WBCs /HPF. Gram stain discloses gram negative rods.What is the recommended treatment?,Which of the following strongly favors the diagnosis of pyelonephritis?,Burning on urination Hematuria Suprapubic tender
19、ness Fever WBC casts on urinalysis,Causes of Meningitis by Age,Beta hemolytic on sheeps blood agar Inhibited by bacitracin dise Inhibited by optichin disc Beta-lactamase positive Growth on MacConkey agar,Meningitis,A 6 year old boy presents with fever and lethargy. He has nuchal rigidity on examinat
20、ion. Lumbar puncture discloses many PMNs and Gram positive cocci in pairs.Which of the following characterizes this organism?,Vaccines are available to prevent meningitis caused by which organisms ?,E. coli and Streptococcus pneumoniae Haemophilus influenzae and Listeria monocytogenes Group B strept
21、ococcus and E. coli Neisseria meningitidis and Haemophilus influenzae Streptococcus pneumoniae and Group B streptococcus,Bone and Joint Infections,Comma-shaped with single polar flagellum Motile and oxidase positive Nonmotile facultative anaerobe Motile and does not ferment lactose Coccobacilli that
22、 require X and V factors,A 22 year-old woman with sickle cell disease presents with fever and pain in the left upper arm. X-ray of the humerus shows a lytic lesion. Biopsy is growing gram negative Bacilli. Which of the following best describes the organism?,Sexually Transmitted Diseases,Gram positiv
23、e coccus, catalase positive Gram positive coccus, catalase negarive, beta-hemolytic Has infectious elementary body and intracellular reticulate body Gram negarive coccus, oxidase positive Gram negarive rod, ixidase negarive lactose fermenting,A 16 year old man presents with burning on urination and
24、a scant urethral discharge 3 days after intercourse with a new partner. Gram stain of discharge discloses many PMNs but no bacteria.The organism most likely responsible for the infection is,Arthritis,Catalase positive, gram positive coccus Gram negative coccus that ferments glucose but not maltose G
25、ram negative coccus that ferments glucose and maltose Gram negative coccus that requries X and V factors for growth Gram negative bacillus that ferments lactose,A 29 yo female presents with fever, rash and arthritis 5 days after onset of menses. She has a new sex partner. Exam discloses about 25 pap
26、ular lesions on distal extremities and inflamed tendon sheaths of the wrists and ankles with painful motion but no fluid in the joints.Cultures of blood and endocervix are growing,Neisseria gonorrhoeae undergoes antigenic variation by altering,Antigenic structure of pilus or expression of outer memb
27、rane protein II Antigenic structure of OMP II or expression of OMP I Expression of polysaccharide capsule Antigenic structure of pilus and expression of OMP I Expression of cytochrome c (Oxidase),Lesion,Gram negative coccobacilli Gram positive cocci in clusters Gram negative diplococci Gram negative
28、 bacilli Motile corkscrew-shaped organisms on darkfield microscopy,A 32 yo homosexual man presents with a painless lesion on the penis of one weeks duration. It developed 3 weeks after unprotected sex with an anonymous partner. The cause of the infection is identified from a specimen obtained from t
29、he lesion which shows.,Response to Treatment,Progressive rise in RPR and reversion of FTA Abs to negative No fall in RPR and reversion of FTA to negative Progressive fall in RPR and reversion of FTA to negative Progressive fall in RPR while FTA remains positive No change in RPR while FTA remains pos
30、itive,A 20 yo asymptomatic woman in the 6th week of pregnancy has a positive RPR of 1:16. FTA Abs is positive. She is treated with 3 doses of benzathine penicillin. Follow up testing after treatment should demonstrate,Discharge,Doxycycline for 5 days Metronidazole single dose Ciprofloxacin single do
31、se Ceftriaxone intramuscular one dose Benzathine penicillin G IM one dose,A 33 yo sexually active woman complains of vaginal discharge. Examination of the greenish frothy discharge discloses pH of 5.5 with numerous WBCs and organisms with a jerking motion on saline wet mount.Treatment is best accomp
32、lished with,Fever and Abdominal Pain,Neisseria gonorrhoeae Treponema pallidum Chlamydia trachomatis E. coli, Prevotella bivia, enterococcus Herpes simplex,An 18 yo woman presents with fever and lower abdominal pain. She has recently had intercourse with a new partner. Pelvic examination discloses va
33、ginal discharge, pain on motion of the cervix and bilateral adnexal fullness.Causes of these symptoms include?,Vaginitis,Metronidazole for 5 days Ciprofloxacin one dose Doxycycline for 5 days Topical acetic acid Topical miconazole,A 35 year old woman complains of scant vaginal discharge and itching.
34、 Exam discloses erythema of the vaginal mucosa with patches of white discharge. The pH is 4.3.What is appropriate treatment for this condition?,Zoonoses,Plague Yersinia pestis,Highly virulent, encapsulated, small gram negative rod Endemic in wild rodents Europe and Western N. America Transmitted by
35、flea Virulence: endotoxin, exotoxin, proteins Spreads to nodes Buboes, severe sepsis Pneumonic plague droplet spread Diagnosis aspirate bubo, blood (careful in lab) Treatment Gentamicin, Streptomycin, tetracycline,Pastuerella multocida,Short, gram-negative rod Cellulitis or osteomyelitis following c
36、at bite or dog bite Treatment penicillin,Anthrax Bacillus anthracis,Gram positive, spore-forming rod with capsule “Box cars”. Spores in soil, on animal productrs Enter through skin, alimentary, respiratory tracts Toxin: Protective antigen, edema factor (cyclase), lethal factor Painless ulcer with ma
37、rked local edema Pneumonia (mediastinitis) meningitis Necrotizing enteritismeningitis Diagnosis-culture Treatment: ciprofloxacin+clindamycin+rifampin, penicillin if susceptible,Gram Stain - CSF,Tularemia,Francisella tularensis small gram negative rod, enzootic in wild animals (rabbit) Transmission t
38、icks or contact with dead animal Clinical Ulceroglandular ulcer with swollen regional lymph nodes Typhoidal fever, adenopathy Pulmonary Diagnosis Culture dangerous in lab; serology and direct fluorescence Treatment Gentamicin or tobramycin,Brucellosis,Small, slow growing gram negative rod B. meliten
39、sis (goats, sheep), B. abortus (cattle), B. suis (swine) Transmission Occupation, milk Small granulomas in lymph nodes, spleen, marrow Fever, weakness, fatigue Diagnosis cluture blood and tissue, serology Treatment tetracycline, gentamicin,Rocky Mountain Spotted Fever,Tick borne rash illness caused
40、by Rickettsia rickettsii, a small gram negative rod. Obligate intracellular parasite. Eastern and Midwestern US Vasculitis organism in endothelium Fever, headache, weakness followed by rash, DiC and shock Diagnosis: Clinical, serology, ElISA, Weil Felix (Culture dangerous) Treatment Doxycycline,Q Fe
41、ver,Coxiella burnetti Transmission contact with infectious aerosol from cattle, sheep, goats. Parturient cats Fever, headache, cough; frequent hepatitis, endocarditis Diagnosis serology Treatment Doxycycline,Lyme Disease,Borrelia burgdorferi spirochete transmitted by Ixodes ticks Reservoir field mic
42、e and deer Erythema migrans, meningitis, encephalitis Heart disease, arthritis Diagnosis Serology ELISA and Western blot Treatment Doxycycline, amoxicillin, ceftriaxone,Fungi,Histoplasmosis,Dimorphic fungus mold in soil, yeast in tissue Ohio and Mississippi river valleys, disturbed soil with bird dr
43、oppings, bat caves Small oval yeast in macrophages Clinical Pulmonary acute pneumonia, chronic like tuberculosis Disseminated in immunocompromised esp AIDS Diagnosis Culture, Serology, Antigen in urine Treatment Self limited, Itraconazole, Amphotericin b,Blastomycosis,Dimorphic fungus large refracti
44、le yeast with broad based budding Ohio, Mississippi, St. Lawrence river valleys, Great Lakes. Soil with decaying organic material Clinical Pulmonary, pneumonia (refractory) Dissemination to skin common Diagnosis culture, histology Treatment Itraconazole, Amphotericin b,Coccidioidomycosis,Dimorphic f
45、ungus mold in soil, spherule in tissue Southwestern US (CA, AZ, NM, TX), Mexico. Arthrospores carried by wind Clinical Valley fever flu, pneumonitis, erythema nodosum Chronic pulmonary thin-walled cavity, nodule Disseminated Filipinos, African Americans, Immunosuppressed, pregnant Skin, bone, joint.
46、 CNS common chronic meningitis Diagnosis Sperules in tissue, culture (DANGER), serology Treatment Amphotericin b, fluconazole, itraconazole,Candida,Oval yeast with single bud. Pseudohyphae in tissue. Many species. Germ tube distinguish C. albicans from others Impaired defenses: Mucosal disease mouth
47、, esophagus, vagina, skin (warm, moist areas) Greater immune compromise dissemination to many organs Diagnosis seen on KOH, Culture Treatment Topical nystatin, azoles Systemic fluconazole, amphotericin b, caspofungin,Cryptococcus neoformans,Oval, budding yeast with polysaccharide capsule Ubiquitous
48、in soil containing bird droppings. Inhaled Compromised: AIDS, diabetes, malignancy, transplant Lung infection Aymptomatic nodule Pneumonia Meningitis common Diagnosis India ink on CSF, Culture, antigen in CSF and serum (follow titer during treatment) Treatment Amphotericin b + flucytosine, Fluconazo
49、le,Aspergillus,Mold (no yeast form), ubiquitous, several species (A. fumigatus most common), Airborne conidia Manifestations Hypersensitivity sinusitis, asthma-like illness (ABPA) Mycetoma fungus ball in pre-existing lung cavity Invasive Severely immunocompromised. sinus and lung Causes thrombosis a
50、nd infarction Disseminated especially to CNS Diagnosis culture and histology Treatment Amphotericin b, Voriconazole, itraconazole,Zygomycosis,Mucor, Rhizopus, Absidia saprophytic molds Invade blood vessels in paranasal sinuses or lung Progressive destruction across tissue planes Diagnosis culture, histology Treatment Surgical debridement Amphotericin b, newer azoles,
