Bacterial Diseases Bacterial Diseases Victor Politi,M.D., FACP, Medical Victor Politi,M.D., FACP, Medical Director, SVCMC School of Allied Director, SVCMC School of Allied Health Professions, Physician Health Professions, Physician Assistant Program Assistant Program
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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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Bacterial DiseasesBacterial Diseases
Victor Politi,M.D., FACP, Medical Director, Victor Politi,M.D., FACP, Medical Director, SVCMC School of Allied Health SVCMC School of Allied Health Professions, Physician Assistant ProgramProfessions, Physician Assistant Program
IntroductionIntroduction
Bacteria consist of only a single cell Bacteria consist of only a single cell Bacteria fall into a category of life Bacteria fall into a category of life
called the Prokaryotes called the Prokaryotes There are thousands of species of There are thousands of species of
bacteria, but all of them are basically bacteria, but all of them are basically one of three different shapes. one of three different shapes.
Classification of Bacteria Classification of Bacteria
Until recently classification has done on Until recently classification has done on the basis of such traits as: the basis of such traits as: shape shape
ability to form spores ability to form spores method of energy production (glycolysis for method of energy production (glycolysis for
anerobes, cellular respiration for aerobes anerobes, cellular respiration for aerobes nutritional requirements nutritional requirements reaction to the Gram stain. reaction to the Gram stain.
Classification of Bacteria Classification of Bacteria
The The Gram stainGram stain is named after the 19th is named after the 19th century Danish bacteriologist who developed century Danish bacteriologist who developed it. it. The bacterial cells are first stained with a purple The bacterial cells are first stained with a purple
dye called crystal violet. dye called crystal violet. Then the preparation is treated with alcohol or Then the preparation is treated with alcohol or
acetone. acetone. This washes the stain out of This washes the stain out of gram-negativegram-negative cells. cells. To see them now requires the use of a counterstain To see them now requires the use of a counterstain
of a different color (e.g., the pink of safranin). of a different color (e.g., the pink of safranin). Bacteria that are not decolorized by the Bacteria that are not decolorized by the
alcohol/acetone wash are alcohol/acetone wash are gram-positivegram-positive
Gram Positive BacteriaGram Positive Bacteria
I-Gram Positive Cocci
A-Streptococcus (e.g. streptococcus Pneumoniae) B-Staphylococcus (e.g. Staph. aureus) C-Enterococcus (Previously Group D Strep.)
I-Beta-hemolytic Streptococcus (Lancefield Groups)I-Beta-hemolytic Streptococcus (Lancefield Groups) -- Group A Streptococcus (Streptococcus Pyogenes) Group A Streptococcus (Streptococcus Pyogenes) -- Group B Streptococcua (Streptococcus agalactiae) Group B Streptococcua (Streptococcus agalactiae) -- Group C Streptococcus Group C Streptococcus -- Group G Streptococcus Group G Streptococcus
III-Non-hemolytic StreptococcusIII-Non-hemolytic Streptococcus -- Streptococcus faecalis (Group D) Streptococcus faecalis (Group D) -- Certain members of Groups B, C, D, H, and O Certain members of Groups B, C, D, H, and O
Strep throat is caused by group A Strep throat is caused by group A StreptococcusStreptococcus bacteria. These bacteria are bacteria. These bacteria are spread through direct contact with mucus from spread through direct contact with mucus from the nose or throat of persons who are infected, the nose or throat of persons who are infected, or through contact with infected wounds or or through contact with infected wounds or sores on the skin sores on the skin
Group B Streptococcus Group B Streptococcus (Streptococcus agalactiae) (Streptococcus agalactiae)
EpidemiologyEpidemiology Most common US cause of neonatal Most common US cause of neonatal
sepsis and meningitis sepsis and meningitis Incidence Incidence
Overall: 2 to 4 per 1000 live births Overall: 2 to 4 per 1000 live births Invasive: 1.8 per 1000 live births Invasive: 1.8 per 1000 live births
Primarily occurs in newborns Primarily occurs in newborns Very rare after 5 months of age Very rare after 5 months of age
PathophysiologyPathophysiology Group B Beta-hemolytic streptococcus infection Group B Beta-hemolytic streptococcus infection Perinatal transmission Perinatal transmission
Delivery via a birth canal colonized with GBS Delivery via a birth canal colonized with GBS Incidence of U.S. vaginal GBS colonization: 15-20% Incidence of U.S. vaginal GBS colonization: 15-20%
Onset of infection (Mean onset 20 hours of life) Onset of infection (Mean onset 20 hours of life) Early onset neonatal disease (<6 days of life in 80%) Early onset neonatal disease (<6 days of life in 80%)
Sepsis Sepsis Pneumonia Pneumonia
Late onset neonatal disease of sepsis or mengitisLate onset neonatal disease of sepsis or mengitis
Group B StreptococcusGroup B Streptococcus(Streptococcus agalactiae) (Streptococcus agalactiae)
Labs: Maternal ScreeningLabs: Maternal Screening GBS Culture GBS Culture ManagementManagement Sepsis (treat for 10-14 days) Sepsis (treat for 10-14 days)
Pencillin G 200,000 units/kg/day divided q4-6 hours Pencillin G 200,000 units/kg/day divided q4-6 hours Meningitis (treat for 14-21 days) Meningitis (treat for 14-21 days)
Penicillin G 400,000 units/kg/day divided q2-4 hours Penicillin G 400,000 units/kg/day divided q2-4 hours PreventionPrevention Perinatal Group B Streptococcus Prophylaxis Perinatal Group B Streptococcus Prophylaxis PrognosisPrognosis Mortality 10-40% Mortality 10-40%
Group B Streptococcus Group B Streptococcus (Streptococcus agalactiae) (Streptococcus agalactiae)
Increasing Pencillin Resistance Increasing Pencillin Resistance Penicillin Sensitive Penicillin Sensitive Ampicilin IV or Amoxicillin PO Ampicilin IV or Amoxicillin PO Erythomycin Erythomycin Azithromycin Azithromycin Clarithromycin Clarithromycin Penicillin G IV Penicillin G IV Doxycycline Doxycycline Oral second generation cephalosporin Oral second generation cephalosporin Parenteral third generation cephalosporin Parenteral third generation cephalosporin
Parenteral third generation Cephalosporin Parenteral third generation Cephalosporin High dose Ampicillin High dose Ampicillin Vancomycin IV with or without RifampinVancomycin IV with or without Rifampin
SignsSigns Toxic appearance Toxic appearance fever fever Tachycardia (out of proportion to fever) Tachycardia (out of proportion to fever) Pharyngeal erythema Pharyngeal erythema Gray-white tenacious exudate or "membrane" Gray-white tenacious exudate or "membrane" Occurs at tonsillar pillars and posterior pharynx Occurs at tonsillar pillars and posterior pharynx Leaves focal hemorrhagic raw surface when Leaves focal hemorrhagic raw surface when
Ingestion of contaminated meat Ingestion of contaminated meat Inhalation of spores Inhalation of spores
Infective aerosol dose: 8,000-50,000 spores Infective aerosol dose: 8,000-50,000 spores Spores may remain viable in soil for >40 years Spores may remain viable in soil for >40 years
No transmission person to person No transmission person to person
Symptoms and Signs: Cutaneous Symptoms and Signs: Cutaneous ("Malignant Pustule")("Malignant Pustule") Inoculation at site of broken skin Inoculation at site of broken skin Painless pruritic pustules develop at Painless pruritic pustules develop at
inoculation site inoculation site Begins as erythematous papule on exposed Begins as erythematous papule on exposed
skin skin Vesiculates and then ulcerates within 1-2 days Vesiculates and then ulcerates within 1-2 days Surrounded by a ring of non-tender Surrounded by a ring of non-tender
Brawny edemaBrawny edema Black eschar may form Black eschar may form
Antibiotic course: Antibiotic course: 60 days 60 days
Empiric Treatment Empiric Treatment Cipro Cipro
Adults: 400 mg IV Adults: 400 mg IV q12 hours q12 hours
Children: 20-30 Children: 20-30 mg/kg/day IV divided mg/kg/day IV divided q12 hours q12 hours
Levofloxacin Levofloxacin Adults: 500 mg IV Adults: 500 mg IV
q24 hours q24 hours
Specific Treatment Specific Treatment for confirmed for confirmed anthrax anthrax Adults Adults
Pencillin G 4 MU IV Pencillin G 4 MU IV q4 hours or q4 hours or
Doxycycline 200 mg Doxycycline 200 mg IV, then 100 mg IV IV, then 100 mg IV q12 hours q12 hours
Children > age 12 same Children > age 12 same as adults as adults
Children < age 12 Children < age 12 Penicillin G 50,000 Penicillin G 50,000
U/kg IV q6 hours U/kg IV q6 hours
Postexposure Postexposure prophylaxisprophylaxis
Concurrently begin vaccination Concurrently begin vaccination Continue antibiotics for 60 days Continue antibiotics for 60 days CiprofloxacinCiprofloxacin
Adults: 500 mg PO bid Adults: 500 mg PO bid Children: 20-30 mg/kg/day divided bid up to 1g/day Children: 20-30 mg/kg/day divided bid up to 1g/day
AmoxicillinAmoxicillin Adults: 500 mg PO tid Adults: 500 mg PO tid Children: 40 mg/kg up to 500 mg PO tid Children: 40 mg/kg up to 500 mg PO tid
DoxycyclineDoxycycline Adults: 100 mg PO bid Adults: 100 mg PO bid Children over age 8: 5 mg/kg/day divided q12 hoursChildren over age 8: 5 mg/kg/day divided q12 hours
Radiology: chest x-rayRadiology: chest x-ray Small pleural effusions Small pleural effusions Unilateral parenchymal infiltrates Unilateral parenchymal infiltrates
Round, fluffy opacities Round, fluffy opacities Spread contiguously to other lobes Spread contiguously to other lobes Progresses to dense consolidation Progresses to dense consolidation Progresses to bilateral infiltrates Progresses to bilateral infiltrates
Fluorescent antibody studies of sputumFluorescent antibody studies of sputum Legionella can not be seen on gram stain Legionella can not be seen on gram stain
High sensitivity/ serogroup 1 High sensitivity/ serogroup 1 Serogroup 1 (LP1) causes most U.S. cases Serogroup 1 (LP1) causes most U.S. cases
Sputum Culture - to ID other serogroups Sputum Culture - to ID other serogroups Urine antigen and sputum culture all cases Urine antigen and sputum culture all cases
Legionella Serologies Legionella Serologies Legionella fourfold titer rise to >= 1:128 or Legionella fourfold titer rise to >= 1:128 or Legionella titer >= 1:256 Legionella titer >= 1:256
Legionella pneumophilaLegionella pneumophila
Management (Antibiotic course for 21 Management (Antibiotic course for 21 days)days)
Azithromycin IV Azithromycin IV Levofloxacin IV Levofloxacin IV Trovafloxacin IV Trovafloxacin IV Erythromycin IV Erythromycin IV
Add Rifampin in immunocompromised or severe Add Rifampin in immunocompromised or severe disease disease
CourseCourse Response to antibiotics may not be seen for 4-5 Response to antibiotics may not be seen for 4-5
days days Up to 15% mortality in some studies Up to 15% mortality in some studies
BrucellosisBrucellosis
EpidemiologyEpidemiology US IncidenceUS Incidence
<100 cases per year (0.34/100,000) <100 cases per year (0.34/100,000)
EtiologyEtiology Brucella abortus Brucella abortus Brucella suis Brucella suis Brucella melitensis Brucella melitensis
Releases endotoxin when dies Releases endotoxin when dies Infective dose: 10-100 organisms Infective dose: 10-100 organisms Incubation: 5-60 days Incubation: 5-60 days
Tissue from Sheep in U.S. Tissue from Sheep in U.S. Unpasteurized milk Unpasteurized milk
Vaccine exposure Vaccine exposure No transmission person to person No transmission person to person Enters via mucus membranes, broken Enters via mucus membranes, broken
skin, or inhalation skin, or inhalation
BrucellosisBrucellosis
Risk FactorsRisk Factors Veterinarians Veterinarians Farm workers Farm workers Meat processing plants Meat processing plants Travel or residence in endemic region Travel or residence in endemic region
Mediterranean Mediterranean India India North Africa, East Africa North Africa, East Africa Central Asia, South Asia Central Asia, South Asia
EpidemiologyEpidemiology Much less common than chlamydia Much less common than chlamydia
Incidence: 500-700,000 cases per year Incidence: 500-700,000 cases per year Decreasing except in inner city, drug abuse Decreasing except in inner city, drug abuse
(crack) (crack) Highly contagious: 50% transmission Highly contagious: 50% transmission Chlamydia coexists in 45-50% of patients with Chlamydia coexists in 45-50% of patients with
Symptoms and Signs: Men (often Symptoms and Signs: Men (often asymptomatic)asymptomatic)
Epidiymitis under age 35 years Epidiymitis under age 35 years Proctitis Proctitis
Receptive anal intercourse or vaginal Receptive anal intercourse or vaginal secretions secretions
Mild anal irritation or itching Mild anal irritation or itching
Neisseria gonorrhoeae Neisseria gonorrhoeae
Symptoms and Signs: Disseminated Symptoms and Signs: Disseminated InfectionInfection
More common in pregnancy More common in pregnancy Dermatitis Dermatitis
Rash over trunk, extremities, palms and soles Rash over trunk, extremities, palms and soles Necrotic pustule on red base over distal extremity Necrotic pustule on red base over distal extremity May become hemorrhagic May become hemorrhagic Usually less than 20 total lesions Usually less than 20 total lesions
Signs: Rash (occurs in 90% of patients)Signs: Rash (occurs in 90% of patients) Onset in first week of illness Onset in first week of illness Characteristics Characteristics
Initial: Blanching Macules 1 to 4 mm in diameter Initial: Blanching Macules 1 to 4 mm in diameter Later: Macules transition to Petechiae Later: Macules transition to Petechiae
Distribution Distribution Onset: Wrists and Ankles Onset: Wrists and Ankles Later: Trunk, Palms and Soles Later: Trunk, Palms and Soles
Positive 7 to 10 days after symptom onset Positive 7 to 10 days after symptom onset Used for confirmation, not for diagnosis Used for confirmation, not for diagnosis
Coxiella burnetii – Q fever, no Coxiella burnetii – Q fever, no arthropod vector cattle,sheep, goats, arthropod vector cattle,sheep, goats, inhallation of dust with dried feces inhallation of dust with dried feces urine or milkurine or milk
organism)organism) Symptoms: WomenSymptoms: Women Vaginal d/c Vaginal d/c dysuria dysuria Pelvic pain Pelvic pain Untreated infections may persist for months Untreated infections may persist for months Usually asymptomatic Usually asymptomatic Urethritis Urethritis
Dysuria-Sterile pyuria Syndrome Dysuria-Sterile pyuria Syndrome Persistent dysuria and pyuria Persistent dysuria and pyuria Negative urine culture Negative urine culture
organism) organism) ManagementManagement Refer all sexual contacts for treatment Refer all sexual contacts for treatment
First Choice First Choice Azithromycin 1 gram PO for 1 dose Azithromycin 1 gram PO for 1 dose Doxycycline 100 mg PO bid for 7 days Doxycycline 100 mg PO bid for 7 days
Alternatives Alternatives Ofloxacin 300 mg PO bid for 7 days Ofloxacin 300 mg PO bid for 7 days Erythromycin 500 mg PO qid for 7 days Erythromycin 500 mg PO qid for 7 days Erythromycin Ethylsuccinate (EES) Erythromycin Ethylsuccinate (EES)
Dose: 800 mg PO qid for 7 days Dose: 800 mg PO qid for 7 days Amoxicillin 500 mg PO tid for 7 days Amoxicillin 500 mg PO tid for 7 days Clindamycin 450 mg PO qid for 14 days Clindamycin 450 mg PO qid for 14 days
Pregnancy Pregnancy Azithromycin 1 gram PO as single dose Azithromycin 1 gram PO as single dose Erythromycin OR EES as above for 7 days Erythromycin OR EES as above for 7 days Amoxicillin 500 PO tid x7 days (Only 50% Amoxicillin 500 PO tid x7 days (Only 50%
effective) effective) Neonates (conjunctivitis or pneumonia)Neonates (conjunctivitis or pneumonia)