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Bacterial Diseases Victor Politi,M.D., FACP, Medical Director, SVCMC School of Allied Health Professions, Physician Assistant Program.

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Presentation on theme: "Bacterial Diseases Victor Politi,M.D., FACP, Medical Director, SVCMC School of Allied Health Professions, Physician Assistant Program."— Presentation transcript:

1 Bacterial Diseases Victor Politi,M.D., FACP, Medical Director, SVCMC School of Allied Health Professions, Physician Assistant Program

2 Introduction Bacteria consist of only a single cell
Bacteria fall into a category of life called the Prokaryotes There are thousands of species of bacteria, but all of them are basically one of three different shapes.

3 Classification of Bacteria
Until recently classification has done on the basis of such traits as: shape bacilli: rod-shaped cocci: spherical spirilla: curved walls ability to form spores method of energy production (glycolysis for anerobes, cellular respiration for aerobes nutritional requirements reaction to the Gram stain.

4 Classification of Bacteria
The Gram stain is named after the 19th century Danish bacteriologist who developed it. The bacterial cells are first stained with a purple dye called crystal violet. Then the preparation is treated with alcohol or acetone. This washes the stain out of gram-negative cells. To see them now requires the use of a counterstain of a different color (e.g., the pink of safranin). Bacteria that are not decolorized by the alcohol/acetone wash are gram-positive



7 Gram Positive Bacteria
I-Gram Positive Cocci A-Streptococcus (e.g. streptococcus Pneumoniae) B-Staphylococcus (e.g. Staph. aureus) C-Enterococcus (Previously Group D Strep.) II-Gram Positive Rods A-Corynebacteria: Corynebacterium diphtheria B-Listeria monocytogenes C-Bacillus anthracis (Anthrax) D-Erysipelothrix rhusiopathiae III-Gram Positive Branching Organisms A-Actinomycetes

8 Gram Positive Cocci I-Beta-hemolytic Streptococcus (Lancefield Groups)
- Group A Streptococcus (Streptococcus Pyogenes) - Group B Streptococcua (Streptococcus agalactiae) - Group C Streptococcus - Group G Streptococcus II-Alpha-hemolytic Streptococcus - Streptococcus Pneumoniae (Pneumococcus) - Viridans streptococcus (bacterial endocarditis) III-Non-hemolytic Streptococcus - Streptococcus faecalis (Group D) - Certain members of Groups B, C, D, H, and O

9 Strep throat is caused by group A Streptococcus bacteria
Strep throat is caused by group A Streptococcus bacteria. These bacteria are spread through direct contact with mucus from the nose or throat of persons who are infected, or through contact with infected wounds or sores on the skin

10 Group B Streptococcus (Streptococcus agalactiae)
Epidemiology Most common US cause of neonatal sepsis and meningitis Incidence Overall: 2 to 4 per 1000 live births Invasive: 1.8 per 1000 live births Primarily occurs in newborns Very rare after 5 months of age

11 Group B Streptococcus (Streptococcus agalactiae)
Pathophysiology Group B Beta-hemolytic streptococcus infection Perinatal transmission Delivery via a birth canal colonized with GBS Incidence of U.S. vaginal GBS colonization: 15-20% Onset of infection (Mean onset 20 hours of life) Early onset neonatal disease (<6 days of life in 80%) Sepsis Pneumonia Late onset neonatal disease of sepsis or mengitis

12 Group B Streptococcus (Streptococcus agalactiae)
Labs: Maternal Screening GBS Culture Management Sepsis (treat for days) Pencillin G 200,000 units/kg/day divided q4-6 hours Meningitis (treat for days) Penicillin G 400,000 units/kg/day divided q2-4 hours Prevention Perinatal Group B Streptococcus Prophylaxis Prognosis Mortality 10-40%

13 Streptococcus Pneumoniae (Pneumococcus)
Epidemiology Most common cause of community acquired pneumonia Classic Symptoms Shaking rigors Fever Purulent sputum Rust colored Pleuritic chest pain Dyspnea Chest splinting

14 Alpha-hemolytic Streptococcus
Lab CBC WBC elevated with left shift Gram stain Gram positive encapsulated organisms Elongated lancet shaped diplococci Blood Culture Positive in only 33% of cases Sputum culture Positive in only 40% of pneumococcal pneumonias Radiology Chest X-ray Lobar consolidation (often lower lobe) patchy infiltrates

15 Management Increasing Pencillin Resistance Penicillin Sensitive
Ampicilin IV or Amoxicillin PO Erythomycin Azithromycin Clarithromycin Penicillin G IV Doxycycline Oral second generation cephalosporin Parenteral third generation cephalosporin

16 Management High-Level Penicillin Resistance
Broad spectrum Fluoroquinolone Levofloxacin Gatifloxacin Grepafloxacin Moxifloxacin Sparfloxacin Parenteral third generation Cephalosporin High dose Ampicillin Vancomycin IV with or without Rifampin

17 Gram Positive Cocci Organisms -Staphylococcus aureus
-Staphylococcus epidermidis

18 Pus smear (wound) Staphylococcus aureus

19 Enterococcus I-Characteristics Gram Positive Cocci
Previously defined as Group D Streptococcus II-Organisms Enterococcus faecalis Enterococcus faecium

20 Gram Positive Rods

21 Corynebacterium Epidemiology Etiology
Rare in United States due to Immunization (DTP, DTaP) However 20% of adults may be inadequate immune status Ongoing epidemic in the former USSR Etiology Corynebacterium Diphtheriae

22 Corynebacterium Symptoms sore throat dysphagia Weakness Malaise

23 Corynebacterium Signs Toxic appearance fever
Tachycardia (out of proportion to fever) Pharyngeal erythema Gray-white tenacious exudate or "membrane" Occurs at tonsillar pillars and posterior pharynx Leaves focal hemorrhagic raw surface when removed Cervical lymphadenopathy

24 Differential Dx Vincent's Angina (trench mouth) Pharyngitis Labs
Also shows pseudomembrane formation Pharyngitis Labs CBC Leukocytosis Throat culture (+ for corynebacterium org.) Management Diphtheria antitoxin Erythromycin 20-25 mg/kg q12 hours IV for 7-14 days Prevention DTP/DTaP vaccination

25 Listeria monocytogenes

26 Bacillus anthracis (Anthrax)
Etiology Bacillus anthracis Transmission Contact with hides of infected animals Cattle Sheep Camels Antelopes Ingestion of contaminated meat Inhalation of spores Infective aerosol dose: 8,000-50,000 spores Spores may remain viable in soil for >40 years No transmission person to person

27 Bacillus anthracis (Anthrax)
Symptoms and Signs: Cutaneous ("Malignant Pustule") Inoculation at site of broken skin Painless pruritic pustules develop at inoculation site Begins as erythematous papule on exposed skin Vesiculates and then ulcerates within 1-2 days Surrounded by a ring of non-tender Brawny edema Black eschar may form

28 Bacillus anthracis (Anthrax)

29 Bacillus anthracis (Anthrax)
Symptoms and Signs: Inhalation Anthrax Malaise Regional lymphadenopathy Two phases Initial Phase Viral upper respiratory symptoms rhinorrhea pharyngitis Later Phase dyspnea and hemoptysis during dissemination


31 Symptoms and Signs: Inhalational Anthrax Acute GI type symptoms
Community acquired pneumonia (late phase anthrax) Mycoplasma pneumonia (early phase anthrax) Influenza (early phase anthrax) Legionnaires' Disease Psittacosis tularemia Q fever Viral pneumonia Histoplasmosis Coccidiodomycosis Acute GI type symptoms Hematemesis Severe diarrhea Differential Diagnosis Cutaneous Anthrax Spider bite Ecthyma gangrenosum Ulceroglandular tularemia Plague Staph. Or strep. cellulitis

32 Bacillus anthracis (Anthrax)
Labs Rapid ELISA test now available Cultures Blood culture (high sensitivity) Cultures of Vomitus or feces (Intestinal Anthrax) CSF culture (Inhalational Anthrax) Nasal Swab (Epidemiologic tool to identify outbreak) Sputum culture (Inhalational Anthrax) Vesicular fluid (Cutaneous Anthrax) Gram stain - blood or vesicular fluid from lesion Gram positive bacilli CBC Neutrophilic leukocytosis in severe cases Radiology: Chest x-ray - Widened Mediastinum (hemorrhagic mediastinitis

33 Management: Antibiotics
Antibiotic course: 60 days Empiric Treatment Cipro Adults: 400 mg IV q12 hours Children: mg/kg/day IV divided q12 hours Levofloxacin Adults: 500 mg IV q24 hours Specific Treatment for confirmed anthrax Adults Pencillin G 4 MU IV q4 hours or Doxycycline 200 mg IV, then 100 mg IV q12 hours Children > age 12 same as adults Children < age 12 Penicillin G 50,000 U/kg IV q6 hours

34 Postexposure prophylaxis
Concurrently begin vaccination Continue antibiotics for 60 days Ciprofloxacin Adults: 500 mg PO bid Children: mg/kg/day divided bid up to 1g/day Amoxicillin Adults: 500 mg PO tid Children: 40 mg/kg up to 500 mg PO tid Doxycycline Adults: 100 mg PO bid Children over age 8: 5 mg/kg/day divided q12 hours

35 Anthrax Course Prognosis Inhalation Anthrax (inhaled spores)
Incubation: 4-6 days Duration of illness: 3-5 days Prognosis Inhalation Anthrax (inhaled spores) Untreated: 95% mortality Treated: 80% mortality Cutaneous Anthrax (skin contact) Untreated: 20% mortality Treated: Rare mortality Intestinal Anthrax (ingested contaminated meat) Mortality 25 to 60%

36 Anthrax Vaccine 93% effective
Prevention Anthrax Vaccine 93% effective Initial: 0, 2, and 4 weeks Next: 6, 12, 18 months and then annually Postexposure Prophylaxis as above Empiric prophylaxis for any suspected exposure Best prognosis with antibiotics prior to symptoms

37 Gram Negative Gram Negative Rods Anaerobes
Bacteroidaceae (e.g. Bacteroides fragilis) Facultative Anaerobes (enteric/nonenteric) Enterobacteriaceae (e.g. Escherichia coli) Vibrionaceae (e.g. Vibrio Cholerae) Pasturella,Brucella,Yersinia Aerobes Pseudomonadaceae (e.g. Pseudomonas aeruginosa)

38 Facultative Anaerobes
Enterobacteriaceae (e.g. E. coli) Vibrionaceae (e.g. Vibrio Cholerae) Salmonella,Shigella,Klebsiella,Proteus GI pathogens !!!!! non-enteric Pasturella,Brucella,Yersinia Francisella,Hemophilus,Bordetella

39 Enterobacteriaceae Characteristics Escherichia coli Klebsiella Proteus
Facultative Anaerobic Gram negative rods EKP Gram negative bacteria Escherichia coli Klebsiella Proteus

40 Vibrionaceae Characteristics Vibrio Cholerae Vibrio parahaemolyticus
Facultative Anaerobic gram negative rods Vibrio Cholerae Vibrio parahaemolyticus Genus: Aeromonas (motile with single polar flagellum)

41 Vibrionaceae Genus: Campylobacter (motile with single polar flagellum)
Campylobacter jejuni Genus: Helicobacter (motile with multiple flagella) Helicobacter Pylori

42 Pasteurellaceae Characteristics
Facultative Anaerobic gram negative rods Genus: Pasteurella Pasteurella multocida

43 Pasteurellaceae Genus: Haemophilus (coccobacilli)
Haemophilus Influenzae Haemophilus aegyptius Haemophilus ducrei

44 Gram Negative Rod Aerobes
Pseudomonadaceae (e.g. Pseudomonas aeruginosa) Brucella Legionellaceae

45 Pseudomonadaceae Characteristics Aerobic Gram Negative Rod
Family: Pseudomonadaceae Pseudomonas aeruginosa Pseudomonas mallei (Glanders)

46 Gram Negative Rod Aerobic
Family: Legionellaceae Legionella pneumophila

47 Legionellaceae Pathophysiology Transmission Transmission Incubation
Aerobic, intracellular, Gram negative rod Virulent organism More severe disease than other atypical pneumonia Transmission Optimal conditions for growth Temperature: 89 to 113 F water Stagnant water Transmission Waterborne Freshwater or moist soil near ponds Air conditioning Condensers Cooling towers Respiratory therapy equipment Showers or water faucets Whirlpools Incubation Two to ten days

48 Legionellaceae Symptoms Prodrome for 12-48 hours Malaise Myalgia HA
Symptoms for 2-3 days Fever to 40.5 C persists for 8-10 days GI symptoms % of cases Nausea/vomiting Diarrhea Later Symptoms: Cough Minimal to no sputum production Slightly blood tinged sputum Signs Severe respiratory distress Confusion Disorientation

49 Legionella pneumophila
Complications Respiratory failure (20-40% of cases) Extrapulmonary complications Myocarditis/pericarditis Prosthetic valve endocarditis Glmoerulonephritis Pancreatitis Peritonitis

50 Legionella pneumophila
Radiology: chest x-ray Small pleural effusions Unilateral parenchymal infiltrates Round, fluffy opacities Spread contiguously to other lobes Progresses to dense consolidation Progresses to bilateral infiltrates

51 Legionella pneumophila
Labs CBC leukocytosis leukopenia Erythrocyte Sedimentation Rate Elevated markedly LFTs increased Sputum Exam Fluorescent antibody studies of sputum Legionella can not be seen on gram stain

52 Legionella pneumophila
Diagnosis Legionella urine antigen testing High sensitivity/ serogroup 1 Serogroup 1 (LP1) causes most U.S. cases Sputum Culture - to ID other serogroups Urine antigen and sputum culture all cases Legionella Serologies Legionella fourfold titer rise to >= 1:128 or Legionella titer >= 1:256

53 Legionella pneumophila
Management (Antibiotic course for 21 days) Azithromycin IV Levofloxacin IV Trovafloxacin IV Erythromycin IV Add Rifampin in immunocompromised or severe disease Course Response to antibiotics may not be seen for 4-5 days Up to 15% mortality in some studies

54 Brucellosis Epidemiology Etiology US Incidence Brucella abortus
<100 cases per year (0.34/100,000) Etiology Brucella abortus Brucella suis Brucella melitensis

55 Brucellosis Pathophysiology Facultative intracellular parasite
Releases endotoxin when dies Infective dose: organisms Incubation: 5-60 days

56 Brucellosis Transmission Infected animal products Vaccine exposure
Tissue from Sheep in U.S. Unpasteurized milk Vaccine exposure No transmission person to person Enters via mucus membranes, broken skin, or inhalation

57 Brucellosis Risk Factors Veterinarians Farm workers
Meat processing plants Travel or residence in endemic region Mediterranean India North Africa, East Africa Central Asia, South Asia

58 Brucellosis Symptoms Intermittent fevers Arthralgia (90%) Weakness
Undulating fever Temperature peaks in evening to Arthralgia (90%) Weakness Lassitude Weight loss Headache Sweating Chills

59 Brucellosis Course Prognosis Weeks to months Case Fatality
<5% treated

60 Gram Negative Cocci Aerobes
Moraxella(Branhamella catarrhalis) Acinetobacter Neisseria

61 Neisseriaceae Neisseria meningitidis Neisseria gonorroeae

62 Neisseria gonorrhoeae
Epidemiology Much less common than chlamydia Incidence: ,000 cases per year Decreasing except in inner city, drug abuse (crack) Highly contagious: 50% transmission Chlamydia coexists in 45-50% of patients with gonorrhea Pathophysiology Incubation: 2-7 days

63 Neisseria gonorrhoeae
Symptoms and Signs: General Urinary Symptoms Urinary frequency Urinary urgency Dysuria Copious urethral discharge Green, yellow, or sanguinous discharge Meatus and anterior urethra inflammation

64 Neisseria gonorrhoeae
Conjunctivitis Direct inoculation Copious exudate Beefy Conjunctiva Serious complications Corneal ulceration or opacification Visual loss Globe perforation Pharyngitis Rarely the only site of infection Usually asymptomatic Acute Diarrhea

65 Neisseria gonorrhoeae
Symptoms and Signs: Women Mucopurulent Cervicitis Often asymptomatic Vaginal d/c or spotting Bartholin’s Gland inflammation Skene's gland inflammation

66 Neisseria gonorrhoeae
Symptoms and Signs: Men (often asymptomatic) Epidiymitis under age 35 years Proctitis Receptive anal intercourse or vaginal secretions Mild anal irritation or itching

67 Neisseria gonorrhoeae
Symptoms and Signs: Disseminated Infection More common in pregnancy Dermatitis Rash over trunk, extremities, palms and soles Necrotic pustule on red base over distal extremity May become hemorrhagic Usually less than 20 total lesions Tenosynovitis Gonococcal arthritis Endocarditis risk

68 Neisseria gonorrhoeae
Complications PID Systemic Gonorrhea Chronic Arthritis Neonatal Gonorrhea Gonorrheal conjunctivitis Preterm labor

69 Neisseria gonorrhoeae
Labs Gram stain: Urethral /cervical smear Numerous WBCs Gram negative biscuit-shaped diplococci False positive Gram stain (saprophytic Neisseria) Gonorrhea culture and Sensitivity Antigen Testing (e.g. Gonozyme) Indicated in symptomatic men Inaccurate in other populations DNA probe testing Rapid: 30 minutes Sensitivity: % Specificity: %

70 Neisseria gonorrhoeae
Management: Drug Resistance Tetracycline resistance: 17-23% Penicillin resistance 15-19% Emerging Fluroquinolone resistance No resistance to 3rd generation cephalosporins Ceftriaxone (Rocephin) Cefixime (Suprax) Azithromycin requiring higher dosages for some GC References

71 Moraxella catarrhalis
Diagnosis Represents less than 5% of all pneumonias More common in COPD Lobar consolidation is rare

72 Moraxella catarrhalis
Labs Gram stain Kidney bean shaped gram negative diplococci Radiology Chest xray patchy bronchopulmonary infiltrate

73 Moraxella catarrhalis
Management: Antibiotic Amoxicillin-clavulanate (Augmentin) Second generation Cephalosporin (e.g. Cefuroxime) 3rd generation Cephalosporin (e.g. Cefotaxime) Erythromycin Azithromycin (Zithromax) Clarithromycin (Biaxin) Trimethoprim Sulfamethoxazole (Bactrim or Septra) Doxycycline

74 Gram Negative Obligate Intracellular Parasites
Rickettsia Ehrlichia Coxiella Rochalimaea (not obligate intracellular)

75 Rickettsia Genus: Rickettsia Typhus Group Spotted Fever Group
Rickettsia prowazekii (epidemic typhus,louse) Rickettsia mooseri Spotted Fever Group Rickettsia rickettsii (rmsf,tick) Scrub Typhus Group Rickettsia tsutsugamushi (scrub typhus,)

76 Rickettsia rickettsii
Pathophysiology Transmission: Tick bite Infects blood vessel walls Endothelial cells Smooth muscle cells Rickettsia rickettsii is causative organism Small pleomorphic organism Obligate intracellular parasite

77 Rocky Mountain Spotted Fever
Epidemiology Bimodal age distribution Ages 5 to 9 years old Age over 60 years old Endemic area North America Atlantic coast states Midwest Central America South America

78 Rocky Mountain Spotted Fever
Symptoms (follows seven day incubation) Fever HA Myalgias Malaise vomiting

79 Rocky Mountain Spotted Fever
Signs: Rash (occurs in 90% of patients) Onset in first week of illness Characteristics Initial: Blanching Macules 1 to 4 mm in diameter Later: Macules transition to Petechiae Distribution Onset: Wrists and Ankles Later: Trunk, Palms and Soles Labs

80 Rocky Mountain Spotted Fever
Labs CBC WBC normal or slightly decreased Thrombocytopenia Liver transaminases increased AST /ALT Serum sodium -Hyponatremia Cerebrospinal Fluid CSF pleocytosis w/monocytic predominance Rickettsia Serology Positive 7 to 10 days after symptom onset Used for confirmation, not for diagnosis

81 Rocky Mountain Spotted Fever
Management Antibiotic Course Minimum course: 5 to 7 days Continue antibiotics until afebrile for 2 days Antibiotics Doxycycline or Tetracycline or Chloramphenicol

82 Rocky Mountain Spotted Fever
Complications Encephalitis Noncardiac pulmonary edema ARDS Cardiac arrhythmia Coagulopathy GI bleeding Skin Necrosis

83 Rocky Mountain Spotted Fever
Prognosis Untreated: 25% Mortality within 8 to 15 days Treated: 5% Mortality

84 Ehrlichia Ehrlichia sennetsu Ehrlichia canis

85 Coxiella Coxiella burnetii – Q fever, no arthropod vector cattle,sheep, goats, inhallation of dust with dried feces urine or milk

86 Rochalimaea (not obligate intracellular)
Rochalimaea quintana (trench fever seen in military settings)

87 Chlamydia Eye Diseases Genitourinary Disease Respiratory Other
Trachoma Inclusion conjunctivitis Genitourinary Disease Lymphogranulmoa venereum Urethritis cervicitis Salpingitis Respiratory Chlamydia pneumonia in newborns Other Chlamydia psittaci (Human psittacosis) Bird borne zoonosis Respiratory illness or typhoidal illness Chlamydia pneumoniae pneumonia

88 Chlamydia trachomatis
Epidemiology: Very Prevalent Asymptomatic teenage female test positive: 5-10% Sexually active persons: 10% Chlamydia 6 to 10 times more common than Gonorrhea Incidence: 3-5 million cases/year

89 Chlamydia Trachomatis (obligate intracellular organism)
Cause Chlamydia Trachomatis (obligate intracellular organism) Complications PID Infertility Preterm labor Perinatal transmission to newborn Chlamydia conjunctivitis Neonatal pneumonia

90 Chlamydia Trachomatis (obligate intracellular organism)
Symptoms: Women Vaginal d/c dysuria Pelvic pain Untreated infections may persist for months Usually asymptomatic Urethritis Dysuria-Sterile pyuria Syndrome Persistent dysuria and pyuria Negative urine culture

91 Chlamydia Trachomatis (obligate intracellular organism)
Symptoms: Men Urethritis Often symptomatic Associated Conditions: Reiter’s Syndrome in Men Arthritis Conjunctivitis

92 Chlamydia Trachomatis (obligate intracellular organism)
Management Refer all sexual contacts for treatment First Choice Azithromycin 1 gram PO for 1 dose Doxycycline 100 mg PO bid for 7 days Alternatives Ofloxacin 300 mg PO bid for 7 days Erythromycin 500 mg PO qid for 7 days Erythromycin Ethylsuccinate (EES) Dose: 800 mg PO qid for 7 days Amoxicillin 500 mg PO tid for 7 days Clindamycin 450 mg PO qid for 14 days

93 Chlamydia Trachomatis (obligate intracellular organism)
Pregnancy Azithromycin 1 gram PO as single dose Erythromycin OR EES as above for 7 days Amoxicillin 500 PO tid x7 days (Only 50% effective) Neonates (conjunctivitis or pneumonia) Erythromycin for 14 days

94 Questions ??????

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