Infectious Disease - Bacterial Infections Lecture Notes PDF

Infectious Disease Bacterial Infections Holistic Clinical Medicine Lecture I Dr. K Wieringa, DMSc, PA-C, CAQ-HM  BLUEPRINT TOPICS - Bacterial Actinomycosis Diphtheria Bacillus anthracis...

Infectious Disease Bacterial Infections Holistic Clinical Medicine Lecture I Dr. K Wieringa, DMSc, PA-C, CAQ-HM  BLUEPRINT TOPICS - Bacterial Actinomycosis Diphtheria Bacillus anthracis Rheumatic fever Escherichia coli Bartonella Rocky Mountain spotted Methicillin-resistant fever Botulism Staphylococcus aureus Salmonellosis Bordetella pertussis Group A Streptococci Shigellosis Haemophiles influenza Brucella Staphylococcus aureus Legionella species Campylobacter jejuni infection Streptococcus Listeria Chlamydia pneumococcus Moraxella catarrhalis Tetanus Clostridium species Neisseria meningitides Tularemia Cholera Neisseria gonorrhea / Vibrio species Clostridioides difficile infection Gonorrhea / Gonoccoal Infections Yersinia pestis Coagulase negative  Actinomycosis Actinomyces species are Gram-positive, anaerobic bacteria, which normally live in the mouth, GI tract, and urogenital tract without causing harm, but become pathogenic if they breach mucosal barriers. The most common sites of infection include the cervicofacial (neck/jaw) area. Its hallmark is the formation of painful abscesses, draining sinuses, and fibrosis. Signs & Symptoms: ◦ Abscess on neck, jaw or face; pain with chewing ◦ Fever ◦ Weight loss Diagnosis: ◦ Physical exam and culture Treatment: ◦ Prolong antibiotics: Penicillin, Doxycycline or Clindamycin Complications: ◦ Local necrosis, infection traveling to other sites (lungs, brain, abdomen, pelvis) HPDP: ◦ No vaccine or prophylactic medication exists ◦ Dental hygiene is paramount Bacillus anthracis Bascillus anthracis is a gram-positive rod which naturally occurs in soil. Bacillus anthracis causes "Anthrax" and presentation depends on how it enters the body. Spores can be weaponized into powders, sprays, food & water and used in bioterrorism attacks o Cutaneous Anthrax: most common form & least dangerous. Infection develops within 2 weeks after exposure § Presents with groups of small bumps and blisters that itch and painless ulcer with black center § Infection is self-limited in most cases o Inhalation Anthrax: lung infection due to inhalation of spores, which starts in lymph nodes of chest and spread systemically, causing breathing issues. Most deadly § Presents w/SOB, cough, sweat, fevers, chills & body aches o GI Anthrax: develops 1-7 days after eating raw meat from infected animal § Presents with n/v, fever, abdominal pain, bloody diarrhea Diagnosis: Culture Treatment: Penicillin or Fluoruoquinolones. Must be reported to the CDC HPDP: A vaccine is available for prophylaxis for those with high risk of exposure (i.e., military). Vaccines can be given for postexposure prophylaxis (which is given along  Bartonella Bartonella henselae causes "Cat Scratch Fever." Cat fleas are the most common reservoir or infection. Signs and Symptoms: oFever, fatigue, headache, malaise, memory loss  Severe infection can include infectious endocarditis, neuroretinitis o Physical Exam: regional LAD, primary skin lesions, joint swelling, neurovascular inflammation Diagnosis: clinically or via tissue/blood cultures Treatment: Supportive care, as is self-limiting within 1-2 months. o Immunocompromised patient: Azithromycin HPDP: No vaccine or prophylaxis available. People who work closely with animals are at highest risk  Botulism Clostridium botulinum is a gram-positive anaerobic bacillus and potent neurotoxin, which blocks the release of acetylcholine that can enter the body via 3 routes: o Food - ingestion of toxin o Infantile - in vivo production of toxin o Wound botulism – common in "skin popping" in IVDU Signs and Symptoms (varies based on cause) o Initial: nonspecific – n/v, constipation, throat complaints o Classic neurological findings: dysarthria, dysphagia, diplopia & mydriasis --> descending symmetric paralysis Diagnosis: Clinically Treatment: Admission to the hospital o Botulinum antitoxin – supplied by health department o Human botulinum immune globulin – for infantile botulism o Intubate & ventilate, respiratory failure o Antibiotics (PCN, Clindamycin), if wound infection only  No antibiotics for food related botulism HPDP: CDC must be notified, and they will verify diagnosis via a murine assay  Bordetella pertussis Bordetella pertussis is a gram-negative coccobacillus spread via respiratory droplets and responsible for Pertussis or "Whooping Cough" Signs & Symptoms occur in 3 stages: Catarrhal Stage (7-14 days): Malaise, rhinorrhea, sneezing, cough – contagious! Paroxysmal Stage (begins week 2 and lasts 2-3 months) Rapid and consecutive coughs followed by a deep, high-pitched inspiration ("whoop") Convalescent Stage (begin 4 weeks after onset of illness) Cough begins to improve Diagnosis: asopharyngeal culture on Bordet-Gengou agar or PCR Complications: Pneumonia, seizures, apnea, death Treatment: Azithromycin or Trimethoprim-Sulfamethoxazole HPDP: Vaccination with the DTaP vaccine! Prophylactic antibiotics should be given to anyone who was exposed to Pertussis within 3 weeks.  Brucella Brucella Signs & Diagnosis: Treatment: HPDP: Symptoms: gram-negative Low grade fever, Culture or Doxycycline and Pasturize milk coccobacilli, weakness, HA, serological tests Rifampin before which can be myalgias, consumption. found in anorexia Vaccinate unpasturized Hepatosplenome livestock to milks and galy on PE prevent/eliminat cheese, and is e transmission responsible for Brucellosis.  Gram-negative rod with most commonly causes acute diarrheal illnesses, found in undercooked poultry, raw milk and contaminated water Signs and Symptoms: o Fever, HA, malaise, myalgias then voluminous the development of several loose, watery stools (most patients have >10 BMs/day), abdominal Campylobac pain/cramping ter jejuni Diagnosis: Stool culture infection Treatment: supportive care; IV fluids and electrolyte replacement if needed o Immunocompromised patients: Erythromycin Complications: Reactive arthritis (2.5% of cases) and Guillan-Barre Syndrome (0.1% of all cases, but C. jejuni is thought to be responsible for 20- 40% of all GBS)  Chlamydia Chlamydia trachomatis is an obligate intracellular gram- negative, anaerobic bacteria responsible for the STI, Chlamydia – the most common STI in Western countries (3-5x's more common than gonorrhea). Signs & Symptoms: Complications: o Urethritis, proctitis, Epididymitis, endocervicitis, PID, perihepatitis (Fitz-Hugh-Curtis Syndrome) Diagnosis: History, physical exam, culture or nucleic acid PCR (preferred) Treatment: Doxycycline HDPD: Safe sex practices with condoms. Doxycycline can be given as postexposure prophylaxis within 72 hours. Patients and their partners should both be treated for gonorrhea and tested for other STIs (e.g., chlamydia, HIV, syphilis)  Clostridium species Clostridium is a spore-forming gram-positive anaerobic bacillus, which produce neurotoxins that inhibit the release of acetylcholine at the neurommuscular junction. There are 3 species: o Clostridium botulinum – Botulism  Addressed earlier in this presentation o Clostridium tenia – Tetanus  Addressed later in this presentation o Clostridium perfringens – Gas gangrene  Addressed in detail in next slide  Clostridium species Clostridium perfringens – Gas Gangrene or Food poisoning. Food poisoning is characterized by watery diarrhea with cramps and little vomiting, typically resolved in 24-hours. Treatment is symptomatic. Food should be adequately cooked to kill the organism Gas gangrene is a life-threatening medical emergency! Gas Gangrene ("Necrotizing Faciitis") Signs and Symptoms: Sudden onset of pain and edema to the area of the contaminated wound with necrosis (gangrene) Crepitus is often present on palpation May develop systemic toxicity with shock Diagnosis: Xray, CT/MRI reveal air in the soft tissues Cultures Treatment: Surgical debridement of wound – this is a surgical emergency and must be done immediately or will result in amputation Penicillin G and Clindamycin ◦ HPDP: There is no vaccine to prevent against Clostridium perfringens Cholera Vibrio cholerae is a gram-negative rod that causes an acute diarrheal illness Signs and Symptoms o Acute, severe, frequent watery stools ("rice water stools"), abdominal pain, vomiting, muscle weakness/cramping, dehydration o On PE, dry mucous membranes, decreased skin turgor and sunken eyes often present Diagnosis: Stool culture vs clinical diagnosis Treatment: § Mild or Moderate illness: oral fluids § Severe illness: IV fluids, electrolyte replacement § Antibiotics: tetracyclines, macrolides and fluoroquinolones are indicated for severely-ill patients to shorted duration of illness HPDP: Vaccines are approved for persons traveling to endemic areas, but in short supply. Important to wash hands, drink clean water ,  Clostridioides difficile infection Previously known as Clostridium difficile. Clostridioides difficile Diagnosis: Stool PCR or antigen test ("C. diff") infection is a bacterium that is present in small o amounts in the body of some people but can become harmful if Also check abdominal XR to rule out given the opportunity for overgrowth, resulting in colitis and megacolon can be life-threatening Treatment: Symptoms: o Oral vancomycin or Fidaxomicin x 10 days o Diarrhea, fever, crampy abdominal pain, anorexia, nausea o Recurrent Infection: Oral vancomycin with Risk Factors: prolonged taper o Recent antibiotic use!!! o If recurrent C. diff occurs after prolonged PO  Be diligent to prescribe antibiotics only when necessary! Vancomycin taper, fecal microbiota transplant o Other risk factors include age >65 y/o, recent hospitalization or nursing home stay, immunocompromised status, previous infection or HPDP: Wash hands with soap and water exposure to C. diff after using the bathroom and before eating. Complications: o As a HCP, antibiotic stewardship is Dehydration, colitis, toxic mega colin, sepsis and death o paramount Loose stools can persist for months after successful treatment o 1:6 patients who get C. Diff will get it again in the subsequent 8 weeks o 1:11 people >65 y/o who will die within 1 month  Coagulase negative staphylococci (CoNS) Gram-positive cocci in clusters. Part Staphylococcus epidermis is the most common coagulase-negative Staph of the normal flora of the human species that lives on the human skin but the most common cause of nosocomial infections in the US skin but an important cause of Commonly infect the following: Prosthetic joints/devices, heart valves (endocarditis), central and IV catheters bloodstream, prosthetic device and wound infections Signs & Symptoms: 2 most common species: Fever, leukocytosis, SIRS, new murmur (endocarditis); inflammation/erythema/purulence (catheter-associated infection), pain/purulence/erthema (prostethetic device infection) o S. epidermis o S. haemolyticus Diagnosis: Culture Must be able to distinguish if true infection versus contamination Treatment: IV antibiotics, typically IV Vancomycin initially Removal of implanted device Some instances require lifelong suppressive antibiotic therapy after initial treatment  Coagulase negative staphylococci (CoNS) Staphyloccus haemolyticus is part of the skin flora, commonly found in the axillae, perineum and inguinal areas Signs and Symptoms: Fever, leukocytosis Severe infections can lead to meningitis, endocarditis, prosthetic joint infections, sepsis Diagnosis: blood cultures Treatment: IV Vancomycin, removal of foreign body, if applicable HPDP: Wash hands often, keep OR sterilized  Diphtheria Diptheria is caused by Corynebacterium diphtheriae, a non- encapsulated gram-positive bacilli in clusters. Signs & Symptoms: o Fever, sore throat, malaise, cervical LAD ("Bull Neck"), HA, dysphagia o Physical Exam: exudative pharyngitis with gray pseudomembrane Diagnosis: Clinical exam and throat culture Treatment: o Hospital admission with droplet isolation precautions o Antitoxin (from CDC) o Penicillin or Erythromycin Complications: o Myocarditis, airway obstruction, polyneuropathy HPDP: DTaP & Tdap protect against Diptheria o Booster required every 10 years  Escherichia coli E. coli are gram-negative bacteria, that are part of the normal intestinal flora of humans and is responsible for several infections, including diarrhea Signs and Symptoms: Severe abdominal cramps, grossly bloody diarrhea, little or no fever Shiga Toxin-Producing E coli (STEC) O157:H7 Live in the intestines of cattle/goat/sheep Hemolytic-Uremic Syndrome (HUS) - life-threatening condition causing hemolysis Complications: of RBC and kidney failure; children