Bacterial Infectious Diseases PDF

# Bacterial Infectious Diseases ## Campylobacter - Reed ### Clinical syndromes Campylobacter enteritis is typically caused by either *C. jejuni** or *C. coli*, both of which cause a gastroenteritis characterized by fever, severe abdominal pain, and diarrhea characterized by loose, watery, or bloody...

# Bacterial Infectious Diseases ## Campylobacter - Reed ### Clinical syndromes Campylobacter enteritis is typically caused by either *C. jejuni** or *C. coli*, both of which cause a gastroenteritis characterized by fever, severe abdominal pain, and diarrhea characterized by loose, watery, or bloody stools. - Fever usually resolves over the first 2 days, while diarrhea and abdominal pain may last 4-6 days. ### Diagnosis: Stool or blood culture - gram-negative curved rods - motile - non-spore-forming - *C. jejuni* and *C. fetus* are neither aerobes nor strict anaerobes, and are adapted for survival in the gastrointestinal mucous layer. ### Body regions - Originally found in the gastrointestinal tract of many animals used for food - GI tracts of many household pets (birds, dogs, and cats etc) - Gastrointestinal most common, but these organisms may cause infections in virtually all parts of the body, especially in immunocompromised hosts. ### Treatment The disease is self-limited, but its duration can be shortened modestly, by about 1 day, with antimicrobial therapy. - Azithromycin, 1 g orally as a single dose or 500 mg orally daily for 3 days. ### Potential sequelae May have late nonsuppurative sequelae. - Reactive arthritis in approximately 2% of those infected. - Guillain-Barré syndrome. - Potentially related to superantigens include multiple sclerosis and Grave's disease. - *C. fetus* causes systemic infections that can be fatal, including primary bacteremia, endocarditis, meningitis, and focal abscesses. It infrequently causes gastroenteritis. ### Relevant species w/in genera - *Campylobacter jejuni* = MOST COMMON (accounts for 80-90% of all cases of recognized illness due to campylobacters and related genera) - Others: - *Campylobacter coli* - *Campylobacter fetus* - *Campylobacter upsaliensis* - *Campylobacter lari* - *Campylobacter hyointestinalis* - *Arcobacter* and *Helicobacter* ## Bordetella Pertussis - Reed ### Clinical syndromes The organism's most important virulence factor is pertussis toxin. - Toxin ADP-ribosylates a guanine nucleotide - Toxin has important mitogenic activity, affects the circulation of lymphocytes, and serves as an adhesin for bacterial binding to respiratory ciliated cells. **Risk:** MC in children < 2 y/o. - Uncommon among infants ≤ 6 months. - Affects 80-100% among unimmunized (Dtap & tdap) household contacts. ### Signs/symptoms 1. Catarrhal phase (1-2 weeks): URI sx, conjunctival, fever, hacking cough that becomes diurnal and increases. 2. Paroxysmal phase (2-4 weeks): severe paroxysmal coughing fits with inspiratory high-pitched whooping sounds after fits. 3. Convalescent phase (begins ~ 4 weeks): resolution of cough, potential pneumonia & failure to thrive. ### Diagnosis: Clinical presentation - Should order nasopharyngeal secretion culture or PCR. - CBC shows absolute lymphocytosis. ### Gram stain/Morphology Small gram-negative coccobacillus - Aerobic - NOT motile. ### Body regions Infection with *B. pertussis* is initiated by attachment of the organism to the ciliated epithelial cells of the nasopharynx. ### Treatment Supportive care as needed + macrolide (Azithromycin PO x 5 days). - Azithromycin safe for pregnant patients - If contraindicated --> use TMP-SMX - Treat within 3 weeks of sx onset OR within 6 weeks if pregnant, immunocompromised, pulm co-morbidity, or age >65. ### Potential sequelae - Subconjunctival hemorrhages, abdominal and inguinal hernias, pneumothoraxes, and facial and truncal petechiae, rib fractures. - Pertussis pneumonia, which occurs in up to 10% of infants with pertussis is usually due to *B. pertussis*. - *B. parapertussis* causes an illness in humans that is similar to pertussis but is typically milder. - *B. holmesii*. - Older children and adults with pertussis, pneumonia is often due to secondary bacterial infection with streptococci or staphylococci. ## Chlamydia - Christian ### Clinical syndromes *C. Trachomatis* - STD that causes lesions of the genitalia. - Serotype A, B, C: present with conjunctivitis. - Serotype L1, L2, L3: present with tender and swollen lymph nodes in groin (lymphogranuloma venereum) - Dx: - Men: urine culture - Women: cervical swab or urine - Followed by NAAT testing of the sample. ### Gram stain/Morphology - Gram- - Anaerobic - Ovoid shape - Non-motile. ### Body regions Oral, vaginal, anal - Conjunctivitis in babies through vaginal canal during birth ### Treatment *Azithromycin* or *doxy* is first line for chlamydia. ### Potential sequelae - PID (50% of cases) - Ectopic pregnancy - Infertility - Urethritis - Epididymitis ### Relevant species w/in genera - *C. psittaci*: affects animal. Typically bird --> human - *C. pneumoniae*: can cause pneumonia - *C. trachomatis*: STD - Shares some of the same risks as HIV. ## Haemophilus - Flu ### Clinical syndromes *H. Flu* - Epiglottitis: - Sx: Abrupt high fever, drooling - Dx: thumb print sign on x-ray. - Meningitis - Otitis media - Septic arthritis - Non-typeable: - Otitis media - Sinusitis - Pneumonia ### Gram stain/Morphology - Gram - Coccobacilli, enters through respiratory tract. - Facultative anaerobe. - Encapsulated: Capsule allows resistance to phagocytosis. Capsule gets broken down in spleen. ### Body regions Mostly nose and throat/ respiratory system - Can get just about anywhere. ### Treatment Antibiotics: - Bactrim if producing a beta lactamase. - First gen cephs if skin infection. - Ampicillin or Rocephin IV for epiglottitis. ### Potential sequelae - Epiglottitis: breathing failure - *H. ducreyi*: painful genital chancre. - *H. aegyptus*: causes conjunctivitis ### Links with other infectious organisms - Considered a opportunistic infection - Can take advantage of a immune system that was already weakened by influenza, RSV. ## Moraxella - Christian ### Clinical syndromes Can cause: - Sinusitis - Otitis media - Bronchitis (opportunistic) - Pneumonia (opportunistic) - Opportunistic infections more common in COPD pt. ### Gram stain/Morphology Gram negative aerobic diplococcus (Extremely similar to *Neisseria*) ### Body regions Very frequently colonizes the respiratory tract of healthy adults. ### Treatment Produces beta lactamase, so preferably treat with antibiotics like Augmentin or Unasyn. ### Potential sequelae - Bacteremia or meningitis in the immunocompromised (not common) - Mastoiditis following Otitis media ### Relevant species w/in genera *Moraxella catarrhalis* - (M. lacunata is a conjunctivitis causing pathogen) - Similar to *Neisseria* sp., Has been found to also cause meningitis and bacteriemia in severely immunocompromised individuals. ## Neisseria - Christian ### Clinical syndromes - Gonorrhea (*N. gonorrhea*) - Colonizes mucosal surfaces of genital tract. - Cervical or penile milky white discharge - Burning dysuria - Dx: urine test male, cervical swab female - Meningitis (*N. Meningitidis*) - Colonizes mucosal surfaces of nasopharynx. - Travels through epithelium to reach submucosa, invades blood stream causing bacteremia and ultimately reaches the meninges where infection occurs. - Petechial rash. - High fever - Mental status changes - Meningismus - Headache - Dx: Lumbar puncture - stain and Cx ### Meningococcal septicemia/meningococcemia (*N. Meningitidis*) - Blood stream infection: - Dark purple petechial rash - Fever - Cold distal extremities - Severe diffuse body pains - Mental status changes - Fatigue - Diarrhea. ### Gram stain/Morphology - Gram negative - Diplococci - Aerobic - *Encapsulated* (only *N. meningitidis*) - Oxidase positive - Have pili and outer membrane proteins - *Obligate human pathogens* ### Body regions *N. meningitidis* is found in the nasopharyngeal region of 3-25% of all individuals (colonization). - *N. gonorrhea* is NOT normal genital flora. Introduced through sexual contact (STI). Can become diffuse infection if untreated. ### Treatment - **Gonorrhea:** - Single IM gluteal ceftriaxone injection (500mg) - Rifampin for prophylactic Tx after exposure. - **Meningococcal meningitis:** - IV ceftriaxone 2g every 12h ### Potential sequelae - **Gonorrhea:** - Vertically transmitted neonatal conjunctivitis - Diffuse Gonococcal infection (Triad: arthralgia, synovitis, rash) *note: not reactive arthritis, that's chlamydia* - **Meningococcal meningitis:** - Hearing loss, seizures, vision damage, neurodevelopmental disability, other permanent neurological damage. ### Relevant species w/in genera - *Neisseria meningitidis* - *Neisseria gonorrhea* ### Links with other infectious organisms Similar morphology to *Moraxella* ## Salmonella - Kylee ### Clinical syndromes Salmonellosis (type of gastroenteritis). - RF: eating undercooked food or improper food prep. - One of the most common causes of diarrhea. - Symptoms develop 12-36 hours after infection. - Spread by eating contaminated meat, eggs, or milk - Symptoms: - Diarrhea, fever, abdominal cramps, vomiting, dehydration - Associated with: - Reactive arthritis and risk of sepsis in immunocompromised/elderly/young - Test stool (Fecal WBCs) or blood. ### Typhoid/Enteric Fever - RF: Poor hand hygiene, lack of access to clean water, eating food handled by an infected person, and living in areas with inadequate sanitation. - Transmitted through contaminated food or drink. - Incubation 5-14 days. - Infects intestines -> lymphatics -> rest of organs. - Symptoms: - Malaise, sore throat, low grade fever, diarrhea, weight loss (pea soup). - Culture in early stages. *gold standard for diagnosis of Salmonella infection is by the culture at the focus of infection: stool, blood, urine, bile, cerebrospinal fluid, and bone marrow.* ### Gram stain/Morphology - Gram negative, motile rod. - Peritrichous flagella. - Non-spore forming. - Facultative aerobe. ### Body regions - Primarily intestines ### Treatment - Salmonellosis: no treatment normally needed: - Can also affect bone, joint, blood. - Correct dehydration and electrolyte imbalances. - Ciprofloxacin in severe illness. - Typhoid fever: Quinolone (Cipro). ### Potential sequelae Typhoid fever can present with: - Neurological complications: delirium, psychosis, acute cerebellar ataxia, and Guillain-Barré syndrome. - Cardiovascular complications: myocarditis and pericarditis. - Gastrointestinal complications: intestinal hemorrhage and perforation. - Reactive arthritis. - Risk of sepsis/shock in immunocompromised/elderly/young - Salmonella bongori: - Cold blooded animals (reptiles) - Salmonella enterica: - Warm blooded animals/environment - Salmonella typhi (enteric fever bacteria!!) - Patients with lower respiratory tract disease (INTS) often have co-infections with other pathogens, such as *Streptococcus pneumoniae* and *Mycobacterium tuberculosis*. ## Borrelia- Kylee ### Clinical syndromes Lyme Disease (borreliosis) - RF: recent hiking/camping. Transmitted via ixodides (deer tick!!). - 3 stages: - Early localized infection (7-10 days after bite) - Erythema migrans (pathognomonic) - Fever, fatigue, malaise, headache. - Early disseminated infection (days to weeks later) - Stiff neck, intermittent musculoskeletal symptoms. - Cardiac (pericarditis, arrhythmias, heart block). - Neurologic (aseptic meningitis, bilateral bell's palsy, encephalitis) - Late persistent infection - Chronic arthritis - CNS/PNS manifestations (encephalopathy) - Diagnostics: - Mostly clinical. - Antibodies can be detected by immunofluorescent assay or ELISA - Western blot assay is confirmatory test. ### Gram stain/Morphology - Spirochetes - Grows slowly and hard to culture in lab. - Skin, joint, heart, brain, bladder. ### Treatment - Doxycycline*** - Amoxicillin (children or pregnant women) ### Potential sequelae - Arthritis, CNS/PNS manifestations, bilateral bells palsy, aseptic meningitis ### Relevant species w/in genera *Borrelia burgodorferi* - A single tick can make a person sick with multiple diseases at once, including anaplasmosis, babesiosis, Powassan virus, and B. miyamotoi infection. ## Staphylococcal - Shelton ### Clinical syndromes *Staph Aureus* - Conditions: skin Infections; Impetigo; abscesses; TSST-1; pneumonia; osteomyelitis - RF: skin & nasal carriage, dec immune system, broken cutaneous barrier (ex. cuts, cracks). - Dx/Testing: positive wound or blood culture - Specific conditions: - Osteomyelitis: bone infection - Etiology: - Non-hematogenous: direct inoculation (bone fx or jt replacement) OR spread from surrounding tissue - Hematogenous: infection that seeds the bone in the setting of bacteremia (from innate inf) - S/Sx: pain, TTP, warmth/redness, fever (bacteremia), malaise, diaphoresis, bone pain - Bacteremia: presence of viable bacteria in the circulating blood - Etiology: - Endocarditis (from vegetation). - Osteomyelitis: - Implantable device or sx hardware - Dx: positive blood culture - Tx: - If skin is the source: 10-14 days abx. - Other: 4-6 wks of IV abx; removal of hardware after stabilization. - Toxic Shock Syndrome Toxin (TSST-1) - Etiology: - Life-threatening complication of bac inf. - D/t Super T-cell antigen - TSST-1 binds to T-cell receptor and MHC II molecules. - Induces expansion of both CD4+/CD8+ subsets of T-lymphocytes (massive T-cell activation and cytokine release). - Release large amts of IL-1/2 and TNF - Associated w/super absorbent tampons, skin wounds (burns) and sx. *Staph Epidermidis* - Etiology: - Part of normal skin flora - RF: Immunocompromised, hospital-acquired, prosthetics devices and indwelling catheters - Bio-films + endocarditis. - Dx: positive blood culture // signs of infection - Tx: 4-6 wks of IV abx // remove device *Staph saprophyticus* - Etiology: - Found in normal flora of female genital tract and perineum - 10-20% of UTI in females 17-27 yo - 2nd most common cause of community-acquired UTIs. ### Gram stain / Morphology - Gram + - Grape-like clusters ### Body regions Skin; Indwelling prosthetic devices; female genital tract/perineum ### Affected - Incision & Drainage - Wound care ### Treatment (Abx/Route) - Abx: - MSSA (methicillin-sensitive): - Penicillin - 1st gen cephalosporin (Keflex) - MRSA (methicillin-resistant) - Bactrim (sulfonamides) - Doxycycline (tetracycline) - Clindamycin - Vancomycin ### Potential complications - Bacteremia ### Relevant species within genera that cause disease - *S. lugdunensis*: Somewhat more aggressive than other coagulase-negative staphylococci. - *S. haemolyticus*: Can cause device-related infections. - *S. simulans*: Can cause device-related infections. - *S. warneri*: Can cause device-related infections. ### Links with other infectious organisms Sepsis; septic arthritis ## Streptococcus - Shelton ### Gram stain/Morphology - Gram + - Arrangement: Pairs / chains (bent/twisted) - Most are facultative anaerobes (grow both Aerobic + Anaerobic) - Species: - α-hemolytic: oxidation of iron in Hgb - β-hemolytic: complete rupture of RBC (wide clear areas on blood agar) - γ-hemolytic: no hemolysis ### Clinical syndromes LIST OF DISEASES: Strep Pyogenes - Pyogenic Pharyngitis (strep throat) - Scarlet fever (s/sx: sandpaper rash, strawberry tongue) - Impetigo - Cellulitis - Toxigenic (Toxic shock-like syndrome) - Immunogenic (rheumatic fever, M-protein antibodies) - Acute glomerulonephritis ### Strep Pharyngitis --> (strep throat) - Etiology: - Group A strep (GAS) aka strep pyogenes - Transmitted vis respiratory droplets or touching. - S/Sx: - Fever, anterior cervical adenopathy, lack of cough, tonsillar exudate, strawberry tongue. - D/Dx: - Inc WBC count w/neutrophils - Rapid strep test + culture. - Tx: Abx (PCN/amoxicillin/Augmentin) ### Strep Skin infection - Etiology: - GAS aka Strep pyogenes (strep is NOT normal flora; inf is secondary to colonization) - Strep spreads through tissue (staph = local) - Dx: positive wound and blood cultures for GAS - Tx: Abx (PCN, 1st gen cephalosporin ex. Keflex, clindamycin) ### Pneumococcal Pneumonia - Etiology (most common community-acquired pneumonia) - Pathogen: - Strep pneumoniae. ### Shape: - Lancet-shaped diplococci. - Facultative anaerobe. - Transmission: respiratory droplets. - IgA protease: protein produced by *S. pneumoniae* that destroys IgA (antibody made by plasma), allowing bacteria to evade the immune system by hindering its ability to neutralize the pathogen at mucosal surfaces (ex. mouth, eyes, respiratory tract). - α-hemolytic: type of pneumonia caused by *S. pneumonia* under aerobic conditions that breaks down RBC. ### S/Sx: - Rusty/red sputum, productive cough, fever, pleuritic pain (chest pain). ### Dx: - CXR (lobular infiltrate or consolidation) - Sputum and blood culture ### Tx: - PCN, 2nd/3rd gen cephalosporin, macrolide (ex. Clarithromycin), fluoroquinolone (ex. Levaquin). ### Prevention - VACCINATE w/PCV15, boost w/PPSV23 1yr later - Conjugate vax has better immunogenicity (more likely to produce immune response). ### Pneumococcal Meningitis (“Bacterial Meningitis”) - Etiology - Pathogen: Strep pneumoniae - CSF leak; pneumonia; sinusitis; head trauma - S/Sx: - Fever; headache; meningismus (neck rigidity w/positive Brudzinski's/Kernig's sign); mental status change (No rash). - Dx: Lumbar puncture (LP) - Bacterial: - Clear, cloudy, or purulent fluid - ↑ opening pressure + protein - ↓ glucose - Elevated neutrophils - Viral: - Clear fluid - Body regions: Skin // respiratory tract - Affected: Normal / ↑ opening pressure; ↑ glucose + protein; Low neutrophils - Treatment (Abx/Route): Abx (PCN) - Potential complications: See above for condition-specific tx. - Complications of strep throat: - Sepsis in pts w/splenectomy - MOPS (Meningitis, Otitis media, Pneumonia, Sinusitis) - Abscess - Glomerulonephritis - Rheumatic heart dz - Relevant Species within Genera that Cause Disease: - Group B, C, G, F, L strep. - Viridans group --> includes *Streptococcus mutans*, *Streptococcus salivarius*, and *Streptococcus sanguinis*. - Links with other infectious organisms: - Scarlet fever, Rheumatic fever. ## Bacillus - Meghan ### Clinical Syndromes ***Anthrax - Bacillus Anthracis*** - 3 Types: - Cutaneous: - Occurs 2 weeks after exposure from spores in soil and contamination through compromised skin barrier. - Large, painless ulcer with black eschar and surrounding edema. - Pulmonary (Inhalation) Woolsorter's disease: - Lung infection through inhalation of spores moving to mediastinal lymph nodes and causing hemorrhagic mediastinitis. - Dry cough, substernal pressure - Gastrointestinal: - Exposure to meat products with spores - N/V/D, fever, bloody diarrhea - Patho: - Exotoxin has three components: protective antigen binds to cells; edema factor is an adenylate cyclase; lethal factor is a protease that inhibits cell growth resulting in cell death (necrosis) - Dx: Mediastinal widening on Chest X-Ray for pulm. - Nonhemolytic colonies on blood agar and colonies on blood agar have flared “comet's tail" appearance. - Tx: Ciprofloxacin and doxycycline - Prevention: 6 dose BioThrax vaccine ### Gram stain/Morphology - Bacillus Anthracis - Large Gram (+) rods, "Box-Car like chains" - Aerobic - Unique capsule of D-glutamate - Spore forming - Nonmotile ### Body regions - Skin, Pulmonary, Gl tract ### Treatment: - Ciprofloxacin or doxycycline ### Potential sequelae - Cutaneous: - Untreated infection can lead to bacteremia. - Pulmonary: - Hemorrhagic meningitis, can rapidly progress to hemorrhagic pleural effusions, shock, death (sepsis) ### Relevant species w/in genera - B. Cereus - Gastroenteritis (food poisoning) - Transmission: Spores on grains such as rice from reheating and kept warm for long time. - Patho: 2 exotoxins: similar to cholera toxin, it increases cyclic AMP, and one similar to staphylococcal enterotoxin, it is a superantigen - Clinical Findings: One syndrome has 4 hr incubation with N/V/D & other syndrome has 18 hr incubation with watery, nonbloody diarrhea. - B. Subtilis - bacteremia, endocarditis, pneumonia, septicemia - Most commonly linked with other infectious organism like Staph, Strep, and Listeria as they are gram (+) and often share similar environments. ## Escherichia (Addy) ### Clinical syndromes - Escherichia Coli - Forms: - EIEC- Enteroinvasive E. coli (uncommon) → bloody diarrhea - ETEC- Enterotoxigenic E. coli → most common cause of traveler's diarrhea - EPEC- Enteropathogenic E. coli → causes watery diarrhea primarily in infants and young children - EHEC (or STEC)- Enterohemorrhagic E. coli (0157:H7) - UPEC- Uropathogenic E. coli → responsible for most UTIs - Transmission: Fecal-oral - If foodborne- undercooked meat, unpasteurized milk, raw fruits and veggies, contaminated water - Others- petting Zoo, improper hand hygiene - MOA: - Food poisoning/Bloody diarrhea: Shiga-toxin (verotoxin) producing E. coli (EHEC) → toxin damages intestinal lining - Sx- vomiting, diarrhea (bloody), abdominal cramps - Dx- + stool culture (using sorbitol-MacConkey agar) - Peripheral leukocytosis 10-20k (most common) - Tx- mainly supportive (rehydration and antidiarrheals), abx NOT recommended first line - If severe (more than six stools per day, fever, dehydration necessitating hospitalization, diarrhea lasting more than seven days, or bloody diarrhea) → cipro, doxy, TMP-SMX (Bactrim) - Hemolytic Uremic Syndrome- Toxin released into blood stream → damages endothelial cells within the glomerulus → inflammation and the activation platelets → decreased platelet count - Sx- abdominal pain/cramps, vomiting, bloody diarrhea, fever, seizures, lethargy, oliguria/hematuria - Dx- - Triad: Hemolytic anemia (d/t microangiopathic hemolysis), AKI, Thrombocytopenia - most common cause of acute renal failure in children - + stool culture or detectable antibody to Shiga Toxin in the blood - CBC- low platelets - CMP- High BUN and creatinine - Normal coag studies (PT, aPTT, Fibrinogen) - Hemolysis- High bilirubin, High LDH, Low haptoglobin + schistocytes on peripheral smear - Tx- mainly supportive, NO antibiotics (can give corticosteroids) - Kidney- Dialysis - Thrombocytopenia- Plasmapheresis/IVIG, blood transfusions PRN - Uncomplicated UTI- UPEC produces α and β-hemolysins → damage of urinary tract cells → inflammation - Transmission: contamination of the vagina from the GI tract (rectum) - Sx- Dysuria, urinary urgency/frequency, suprapubic pain, back pain (if pyelonephritis), hematuria - Dx- + UA (nitrates, leukocyte esterase), CBC- Normal WBC count - Tx- Nitrofurantoin, TMP-SMX (Bactrim), cipro ## Shigella - Eric ### Clinical syndromes - Shigellosis - Shigella can cause disease only in primates. - Transmitted by fingers, flies, food, and feces. - Fecal-oral route - Incubation 1-4 days - Produces shiga enterotoxin that is neurotoxic, cytotoxic, enterotoxic. ### At risk: - Children in daycare centers - Travelers to endemic regions - Immunocompromised ### Sx/symptoms: - Bloody, mucoid diarrhea - dysentery - High fever - Abdominal cramps, tenesmus - urge to defecate with little stool - Nausea and vomiting - Loss of appetite - Neurological manifestations - Especially in younger children, febrile seizures, encephalopathy. ### Diagnosis: - Stool culture: definitive, isolate shigella species, positve fecal WBC and RBCs (inflammatory invasive diarrhea) - PCR testing: rapid identification ### Lab - Elevated WBC count in stool microscopy - May have mild leukocytosis - Sigmoidoscopy - reveal punctate areas of ulceration and inflammation. ### Treatment - Mild cases: - Suppurative care (rehydration, rest) - Generally self limiting - Anti-motility drugs should be avoided. - Severe cases: ciprofloxacin (1st line adults), azithromycin (1st line in children) ### Gram stain/Morphology - Gram negative rod - Facultative aerobe ### Body regions - Highly virulent infection of colon, usually rectosigmoid portion of colon. ### Treatment - See above. ### Potential sequelae: - Reactive arthritis, hemolytic uremic syndrome, toxic megacolon, proctitis, rectal prolapse, interstitial obstruction, colonic perforation. ### Relevant species w/in genera - Shigella Sonni (most common in US) - Shigella flexneri (common in developing countries, linked to reactive arthritis) - Shigella dysenteries – severe dysentery, associated with shiga toxin production - Shigella boydii – rare, typically isolated in south asia ### Links with other infectious organisms - E coli, salmonella, entamoeba histolytica (clinically mimics), rotavirus, norovirus ## Mycobacteria - Eric ### Clinical syndromes - Forms: - Tuberculosis: - Leading cause of death from infectious agent worldwide - Mycobacterium avium complex - Mycobacterium marinum - Transmission: - TB: - Inhalation of infected aerosolized microdroplets - Prolonged exposure, increase risk of infection - MAC: - Present in soil and water - Marinum: - Inoculation of break in skin barrier with exposure to contaminated fresh or salt water, including aquariums, marine organisms, and swimming pools - Risk: - TB: - Close contact with active TB, immigrant from endemic region, crowed conditions (prsion, homeless shelter), healthcare workers, lab workers, HIV, DM, immunosuppression, kids under 5, injection drug and alch, over 65 - MAC: - Underlying pulmonary disease (bronchiectasis, COPD) - Immunocompromised- HIV with CD4 less than 50 - Marinum: - Occupational hazard of aquarium handlers, marine workers, fisherman, and seafood handlers - Clinical manifestations: - TB: - Pulmonary: - Prolonged fever, cough (often mild and nonproductive but can be productive, > 2-3 weeks), chest pain, dyspnea, hemoptysis, chills, night sweats - Lymadenopathy, fatigue, pharyngitis - Consumption and malaise - Extrapulmonary: - Can affect any organ – cervical lymph nodes (scrofula), meningitis, Pott disease, milary Tb, pericarditis, adrenal gland involvement, UG - Physical exam: - Crackles, signs of consolidation - Clubbing - MAC: - Pulmonary: - Present similar to TB. - Disseminated: - Fever of unknown origin, sweating, weight loss, fatigue, diarrhea, dyspnea - Lymphadenitis in children - age 1-4, prim involving unilateral cervical lymph nodes - Marinum: - Localized cutaneous disease - erythematous bluish papule or nodule at site of trauma, can ulcerate - Subsequent lesion may occur along path of lymphatic drainage - Diagnosis: - TB: - Isolation from body secretion, fluid, or tissue - Sputum acid fast staining: if imaging suspicous of TB 3 sputum specimens, AFB smear, mycobacterial culture - NAA testing - positive NAA sufficient to dx - Histology - caseating granulomas - Tuberculin skin test - Interferon gamma release assay - Chest xray: - Prim TB - middle/lower lobe consolidation - Reactive TB - focal infiltration (pathy or lobar consolidation) upper lobes, cavities in upper portion of lungs - Miliary TB - small fibronodular lesion - MAC: - Acid fast bacillus staining and culture sputum, blood and urine if disseminated suspected - x-ray indistinguishable from T---------- - Marinum - Culture - Treatment: - TB: - Active TB: - 4 drug RIPE treatment, all 4 for 2 months, Rifampin and isoniazed for 4 more months - Streptomycin can be used for ethambutol - Latent TB: - Rifampin daily 4 months - ISO and Rif daily 3 months - Iso monotherapy for 6-9 months - MAC: - Triple therapy: clarithromycin + ethambutol + rifamycin/rifampin - Amikan can be added in life threatening situation - Prophy in HIV: Claritho or Azithro with cd4 below 50 - Marinum: - Superficial papules – clarithro or bactrim - Deeper/more extensive - clarithro combo ethambutol or rifampin. - Typically 3-4 months - Gram stain/Morphology: - Gram positive acid fast bacilli - Rod shaped - Non-motile with high lipid content in cell wall - Detected using acid fast staining – high levels of mycolic acid in cell walls - Fluorescent stains such as auramine - Body regions: - TB - primary lung, lymph nodes, cns, bones, and UG tract, kidney, spine - MAC - lungs, lymph nodes, disseminated - Marinum - skin, soft tissue - Treatment: See above - Potential sequelae: - TB: - Fibrosis, chronic pulmonary complications, neurological deficits (TB meningitis), spinal deformity (Potts) - NTM: - Chronic lung damage, recurrence - Mac: - m. tuberculosis, m. bovis, m. africanum - Marinum: - M. avium, M. intracellulare - M. Marinum - Links with other infectious organisms: - HIV - Fungal co-infection – histoplasma, cryptococcus - Bacterial superinfections