CHAPTER 3 PART 2

Clinical Findings for Streptococcus pyogenes

• TONSILLOPHARYNGITIS

• SCARLET FEVER

• Seasonal occurrence

• Involves children 5-10 years of age

• Secondary peak at 12 and 18-20 years of age

TONSILLOPHARYNGITIS

Sign and Symptoms

• sudden onset of fever, sore throat, headache, nausea, malaise, pain, and marked tonsillo-pharyngeal erythema

TONSILLOPHARYNGITIS

Complications:

• sinusitis, otitis media, pertonsillar and retropharyngeal abscess, acute rheumatic fever, and acute glomerulonephritis

TONSILLOPHARYNGITIS

Diagnosis for TONSILLOPHARYNGITIS

Culture of specimen (swab)

Treatment for TONSILLOPHARYNGITIS

• self- limited

• DOC: PENICILLIN

• ALT.: ERYTHROMYCIN or CLINDAMYCIN

Occurs in association with streptococcal pharyngitis

Scarlet Fever

Sign and Symptoms:

• pinkish-red rash on the skin

• spotted strawberry-like appearance of the tongue

• skin peels off similar to sunburn (as the disease progresses)

Scarlet Fever

Treatment or DOC for Scarlet Fever

PENICILLIN G

• “Pneumococci”

• Gram (+),

• encapsulated,

• lancet-shaped diplococci

• Alpha-hemolytic (causes partial hemolysis)

• Normal inhabitants of the URT;

• transient flora of the nasopharynx

Streptococcus pneumoniae

the virulence factor of Streptococcus pneumoniae

Capsule (anti-phagocytic)

Mode of Transmission:

• Droplet respiratory secretions

• Nasopharyngeal carriers (10% cases)

Streptococcus pneumoniae

clinical findings for Streptococcus pneumoniae

• Chronic cardio-pulmonary disease

• Otitis media ( middle ear)

• Sinusitis (sinuses)

• Mastoid

• Meninges

• follows URT infections

• Begins with abrupt onset of fever and chills, cough and pleuritic chest pain

• Sputum is RED or BROWN (“rusty”) in color

Chronic cardio-pulmonary disease

Laboratory Diagnosis for Streptococcus pneumoniae

• Gram’s stain

• Microscopic examination (sputum)

• Capsular swelling test (Quellung Reaction)

• Optochin sensitivity

Treatment and prevention for Streptococcus pneumoniae

• DOC: PENICILLIN G

• Alt.: CEFTIZOXIME and VANCOMYCIN

• Prevention: PNEUMOCOCCAL CONJUGATE VACCINE

it is also called as “blood-loving”

Haemophilus

• Haemophilus – “blood-loving”

• Found on the mucous membranes of the URT

• Most infections occur in children 6 months-6 years

Haemophilus infuenzae

the virulent factor of Haemophilus influenzae and the most virulent

• Capsule (anti-phagocytic)

• H. influenzae type b (encapsulated strain)

Mode of Transmission for Haemophilus influenzae

it enters the body through the URT

Clinical findings of Haemophilus influenzae

• Sinusitis and Otitis media (2nd to Pneumococci)

• Epiglottidis (exclusively caused by H. influenzae)

• Meningitis (SSx: Fever, Headache, Stiff neck along with drowsiness)

• Bronchitis and Pneumonia (commonly seen in elderly adults with chronic respiratory disease)

Laboratory Diagnosis for Haemophilus influenzae

• Microscopic Examination

  ▪︎ SPECIMEN (Nasopharyngeal swabs, pus, blood, and spinal fluid)

Treatment and prevention for Haemophilus influenzae

• DOC: AMPICILLIN (non beta-lactamase producing strains)

• Newer Cephalosporins (all strains)

• Prevention: H. influenzae type b conjugate vaccine (Hib vaccine) to children

• Smallest free-living organisms that can self-replicate in laboratory media

• Produces tiny colonies on special agar that have a "fried egg" appearance

• Cell wall-less organism (cell membrane = sterol)

• Part of mouth’s normal flora

Mycoplasma pneumoniae

mode of transmission for Mycoplasma pneumoniae

person-to-person (infected respiratory secretions)

Clinical findings for Mycoplasma pneumoniae

• Atypical or Walking Pneumoniae

  ☆ Asymptomatic carriers

  ☆ Tracheobronchitis with low grade fever, pharyngitis, malaise and non-productive cough

Laboratory Diagnosis for Mycoplasma pneumoniae

Serologic Testing

Treatment and prevention for Mycoplasma pneumoniae

• DOC: MACROLIDE or TETRACYCLINE

• An opportunistic pathogen (community-acquired/nosocomial infections)

  ☆ Elderly patients

  ☆ Diabetics

  ☆ Alcoholics

  ☆ Chronic respiratory tract

• Frequently found in the large-intestine

• Found also in soil and water

• Very large capsule (anti-phagocytic)

Klebsiella pneumoniae

Clinical findings for Klebsiella pneumoniae

• Lobar Pneumonia – thick, bloody sputum (“currant jelly”)

• Necrosis and abscess formation are common

Laboratory Diagnosis for Klebsiella pneumoniae

• Differential Media: MacConkey’s Agar and EMB

• Biochemical Tests

Treatment and prevention for Klebsiella pneumoniae

• Highly resistant to antimicrobial drugs

• DOC: Sensitivity Testing

• Gram (-) rods

• It can survive inside macrophages and alveolar cells

Legionella pneumophila

what is the virulence factor of Legionella pnuemophila

LPS

mode of transmission for Legionella pneumophila

• Lakes,

• streams,

• air conditioners,

• and water-cooling towers

clinical findings for Legionella pneumophila

• Pontiac Fever

• Legionnaire's Disease (Legionellosis)

• A mild flu-like form of infection

• Does not result in pneumonia

• Abrupt but resolves completely in < a week

Pontiac Fever

• Atypical type of pneumonia

• Very high fever and severe pneumonia accompanied by mental confusion and non-bloody diarrhea

• Can be fatal

Legionnaire's Disease (Legionellosis)

laboratory diagnosis for Legionella pneumophila

• Dieterle and Warthin-Starry Silver Stains (Silver Impregnation Method)

• Monoclonal or Polyclonal immunofluorescent

  Antibody Staining

Treatment and prevention for Legionella pneumophila

• Macrolides

• Fluoroquinolones

• Small,

• encapsulated,

• Gram (-) rod

Bordetella pertussis

Mode of Transmission for Bordetella pertussis

Airborne droplets ( severe coughing episodes)

Stages of Whooping Cough ( Pertussis)

• Catarrhal Stage

• Paroxysmal Stage

• Convalescent Stage

stage of whooping cough where:

• Most contagious (greatest number of Mos)

• 1-2 weeks

• Mild URT infection with non-specific signs and symptoms

Catarrhal Stage

stage of whooping cough where:

• 5-20 forceful, hacking coughs with the production of abundant amounts of mucus that ends in a high-pitched indrawn breaths (“whoop noise”)

• 2-10 weeks

• Patient may turn cyanotic, the tongue protrudes, the eyes bulge, and neck veins engorge

Paroxysmal Stage

stage of whooping cough where:

• Reduction of symptoms leading to recovery

• Patient is no longer contagious

Convalescent Stage

complications of Bordetella pertussis

• Pertussis, like measles, can unmask underlying

  tuberculosis

• Convulsions may occur due to cerebral anoxia

  during coughing spells

• Blindness (from hemorrhages into conjunctiva

  during paroxysms)

• Pneumonia,

• deafness, and

• hernias

Laboratory Diagnosis of Bordetella pertussis

• Culture of specimens (nasopharyngeal swabs – taken during paroxysmal stage)

  ☆ Regan Lowe Charcoal Medium

Treatment and Prevention of Bordetella pertussis

• DOC: MACROLIDES (patients and exposed individuals)

• Supportive care: Oxygen Therapy and Suctioning of mucus

• Prevention: Acellular Vaccine

• Acid-fast,

• obligately aerobic bacillus

• Cell Wall - Mycolic Acid

Mycobacterium tuberculosis

mode of transmission of Mycobacterium tuberculosis

• Person-to-person (respiratory aerosols)

• Fomites (utensils and galsswares)

transmitted through ingestion of contaminated cow’s milk —— GI tuberculosis

M. bovis

clinical findings of Mycobacterium tuberculosis

Koch's Disease (Tuberculosis)

• 1° Infection/ Complex

• 2° Infection/ Reactivation Pulmonary Tuberculosis

• Disseminated/ Extrapulmonary Tuberculosis

• Initial infection in childhood

• May affect any part of the lungs (most cases – middle and lower lobes)

• Ghon Complex (Lesion)

• Asymptomatic (most ptx)

1° Infection/ Complex

• Caused by Mos that have survived in the 1° lesion

• Almost always begins at the apex (highest oxygen tension)

• S/Sx: fatigability, afternoon rises in temp, weight loss, night sweats, loss of appetite, chronic non-productive cough with or without hemoptysis.

2° Infection/ Reactivation Pulmonary Tuberculosis

• Multiple disseminated lesions

• Initial organs affected – lymph nodes

• Scrofula – aggregation and ulceration in the lymph nodes

• Forms: TB meningitis, TB osteomyelitis (Pott’s

  disease), GI TB, Oropharyngeal TB, Renal TB, GU TB, PerIcardial TB

Disseminated/Extrapulmonary Tuberculosis

Diagnosis for Mycobaterium tuberculosis

• Acid-Fast Staining of Sputum

  ☆ 2 collections – 0 hr and 1hr

  ☆ Medium: Lowenstein-Jensen

• Chest X-ray

• Tuberculin Skin Test (Mantoux – intradermal test)

treatment and prevention for Mycobacterium tuberculosis

Bacillus Calmette-Guerin (BCG) vaccine

clinical findings for Bacillus anthracis

ANTHRAX

• Cutaneous

• Gastrointestinal

• Pulmonary/Inhalation Anthrax (Woolsorter’s Disease)

  edema, enlargement of mediastinal lymph nodes (Chest X-ray - widening of the mediastinum), bloody pleural effusion, septic shock, and death

complications of Bacillus anthracis

• Hemorrhagic meningitis

• Hemorrhagic mediastinitis

treatment for Bacillus anthracis

• DOC: CIPROFLOXACIN

• Alt.: DOXYCYCLINE

Bacterial Infections of the GIT

• Gastritis

• Enteritis

• Colitis

• Gastroenteritis

• Hepatitis

• Dysentery

how does disease occur in the GIT?

1. Pharmacologic Action

   • Toxins

2. Local Inflammation

   • Invasion of the alimentary tract by microbes

3. Deep Tissue Invasion

   • Spread of the MO to the adjacent tissues

4. Perforation

   • Normal Flora spills into sterile areas

• alter normal intestinal function without lasting damage to their targeted cells

• Ex: Vibrio cholerae (Cholera toxin–epithelial cells)

Toxins

• usually limited to the epithelial layer but may spread to the deeper tissues.

• Ex: mouth (periodontitis) and intestine (dysentery)

Invasion of the alimentary tract by microbes

• enters the bloodstream

• Ex: Strongyloides stercoralis (burrowing through the intestinal wall called POLYMICROBIAL SEPTICEMIA)

Spread of the MO to the adjacent tissues

• invades deep tissues

• Ex: perforation of the inflamed appendix- peritonitis

Normal Flora spills into sterile areas

Causative agents of Dental Caries (tooth decay)

• Streptococcus mutans (primary)

• Actinomyces

• Lactobacilli

prevention of Dental Caries

• Minimal ingestion of sucrose,

• Brushing,

• Flossing,

• Regular dental visits,

• use of fluoride, chlorhexidine (mouthwash)

inflammation and degeneration of structures that support the teeth

Periodontal Disease

the causative agent of Periodontal Disease

• Streptococci

• Actinomycetes

• Anaerobic Gram (-):

  1. Prevotella

  2. Bacteroides

  3. Fusobacterium nucleatem

• Reversible inflammation of the gums

• Bleeding of the gums while brushing the teeth

Gingivitis

• Severe/chronic gum disease

• Bone destruction and tooth loss

• Gums are inflamed and bleed easily

Periodontitis

• Serious, pain that prevents normal chewing

• Halitosis

• Prevotella intermedia (primary)

Acute Necrotizing Ulcerative Gingivitis / Vincent’s DSE / Trench Mouth

Virulence Factors:

• Rapid Motility (penetration of the lining of the stomach)

• Urease Production (production of large amounts of ammonia from the urea (neutralization of gastric acid))

Helicobacter pylori

mode of transmission of Helicobacter pylori

• Ingestion

• Person-to-person via the saliva

clinical findings of Helicobacter pylori

• Gastritis

• Peptic Ulcer

laboratory diagnosis for Helicobacter pylori

• Histologic examination

• Culture

• Measurement of antibody levels

treatment for Helicobacter pylori

• Triple Therapy

  Proton pump inhibitor ( OMEPRAZOLE) + Macrolide ( CLARITHROMYCIN) + AMOXICILLIN

• Similar symptoms occur in several members of a group who share the same meal

• Onset of symptoms occurs a few hours after food ingestion

Bacterial Enterocolitis ( Food poisoning)

the 3 mechanisms of Bacterial Enterocolitis ( Food Poisoning)

1. Ingestion of preformed toxin may be present in contaminated food ( Staphylococcus aureus, Vibrio, and Clostridium perfringens)

2. Infection by toxigenic organisms

3. Infection by an enteroinvasive organism

• Gram (+) aerobic bacillus

Bacillus cereus

clinical findings of Bacillus cereus

1. Emetic Type

2. Diarrheal Type

• incubation period (1-6 hours)

• nausea, vomiting, abdominal cramps, and occasionally diarrhea

• self-limited (recovery: 24 hours)

• source: re-warmed rice and pasta dishes

Emetic Type

• incubation period (6-24 hours)

• profuse diarrhea with abdominal pain and cramps

• Enterotoxin may be produced in the intestine

• Source: meat, poultry, and vegetables

Diarrheal Type

laboratory diagnosis for Bacillus cereus

Isolation of the organism from the suspected food samples followed by culture

treatment and prevention for Bacillus cereus

• Fluid and electrolyte replacement

• Self-limited

• Preventive Measures:

  1. Preventing contamination by soil

  2. Rice should not be kept warm for long periods

• Causes food poisoning with the shortest incubation period (Average: 2 hours)

• Enterotoxins – produced when the MO grows in food-rich in CHO and CHON

Staphylococcus aureus

mode of transmission for Staphylococcus aureus

• Ingestion of contaminated food – salads, custards, milk products, and processed meat

• Carriers and individuals shedding human lesions

• Fomites contaminated with human lesions

clinical findings for Staphylococcus aureus

• Vomiting and Nausea (more prominent than diarrhea)

• Toxin – acts on neural receptors in the gut

laboratory findings for Staphylococcus aureus

Isolation of the organism from the suspected food samples followed by culture

treatment and prevention for Staphylococcus aureus

• Self-limited

• Fluid and electrolyte replacement

• Preventive Measures:

  1. cleanliness

  2. hygiene

  3. aseptic management of lesions

mode of transmission for Clostridium perfringens

Ingestion of preformed toxin from food-contaminated soil containing the MO’s spores – meat dishes

clinical findings for Clostridium perfringens

• Incubation Period: 9-15 hours

• Watery diarrhea with abdominal cramps

• Self-limiting (24 hours)

treatment and prevention for Clostridium perfringens

• Fluid and Electrolyte replacement

• Preventive measure:

  1. adequately cook food before consumption

• Marine organism – bacterial gastroenteritis associated with seafood.

• Curved, Gram (-) coccobacillus

• Halophilic (requiring 80% NaCl solution for growth)

Vibrio parahaemolyticus

toxin that can is present in Vibrio parahaemolyticus

Kanagawa hemolysin (enterotoxin similar to the cholera toxin)

mode of transmission for Vibrio parahaemolyticus

• Ingestion of raw or undercooked seafood (shellfish – oysters)

• Philippines - milkfish

clinical findings for Vibrio parahaemolyticus

• Mild to severe watery diarrhea, nausea, vomiting, abdominal cramps, and fever

• Self-limited (3 days)

laboratory diagnosis of Vibrio parahaemolyticus

Culture (Thiosulfate–citrate–bile salts–sucrose agar) TCBS Agar