MICROPARA LE 4: MISC. BACTERIA

miscellaneous bacteria

• bacillus anthracis

• listeria monocytogenes

• legionella pneumophilia

• mycoplasma pneumoniae

bacillus anthracis

miscellaneous bacteria

• aka ANTHRAX BACILLUS

• lagest pathogenic acilli

• gram positive

• rod-shaped

• non-motile bacteria

• halophilic organisms (withstands upto 7% of sodium hypochlorite)

• endospore forming

• can be gornw under both aerobic and anaerobic conditons

• not part of the indigenous human microbiota

anthrax

• caused by bacillus anthracis

• can cause severe illness in both humans and animals

• people usually get this illness from infected animals or even through contaminated animal products

types of anthrax

• cutaneous anthrax

  • the most common form of anthrax infection, considered to be least dangerous

  • small papule

  • “black eschar”

• pulmonary anthrax / woolsorter’s disease

  • acquired when spores are inhaled into the pulmonary parenchyma

  • resembles upper respiratory tract infection

  • causes severe breathing problems and may lead to death

  • s/s: mild fever, fatigue, malaise, and dyspnea

• gastrointestinal anthrax

  • rare but potentially fatal

  • cause by ingesting undercooked meat from an infected animal

  • usually affects the esophagus, throat, stomach, and intestines

  • s/s: abdominal pain, nausea, anorexia, vomiting, and bloody diarrhea

cutaneous anthrax

type of anthrax

• caused by bacillus anthracis

• most common form of anthrax infection but also considered to be the least dangerous

• it is acquired through skin cuts and abrasions

• a small papule appears at the site of the spore inoclutaion 2-5 days after exposure

• characterized by teh appearance of “black eschar” which is a black, necrotic and painless central area that does not produce pus

pulmonary anthrax

type of anthrax

• caused by bacillus anthracis

• aka woolsorter’s disease

• acquired when spores are inhaled into the pulmonary parenvhyma

• resembles an upper respiratory tract infection

• causes severe breathing problems breathing problems and may lead to death

• s/s: mild fever, fatigue, malaise and dyspnea

gastrointestinal anthrax

type of anthrax

• caused by bacillus anthracis

• a rare but potenially fatal form of anthrax infection

• caused by ingesting undercooked meat from an infected animal

• causes lesions and dinflammation from the throat to the colon

• the bacteria usually affects the esophagus, throat, stomach, and intestines

• s/s: abdominal pain, nausea, anorexia, vomiting, bloody diarrhea

laboratory diagnosis for bacillus anthracis

• specimen: malignant pustules, sputum, blood

  • processing of samples for b. anthracis should be sone ina biologically saftey cabinet level 3

• spore stain: Malachite green and McFadyean stain

• direct fluorescent antibody test: diagnostic test

management and treatment for bacillus anthracis: treatment and mechanisms

• antibiotics

  • oral injectable, or intravenous antibiotics for 60 days

  • commonly used: CIPROFLOXACIN and DOXYCYCLINE

• antitoxins

  • these injectable antibody mediaction neutralize anthrax toxins in the body

  • typically includes antibuiotics too

• vaccine

  • vaccine to prevent anthrax infection,

  • BioThrax, treats infected people

  • treatment involves three doses of the vaccine over four weeks

  • receive antibiotics at the same time

management and treatment for bacillus anthracis

• antibiotics: ciprofloxacin and doxycycline

• antitoxins

• vaccine: BioThrax

listeria monocytogenes

type of miscellaneous bacteria

• gram positve

• rod shaped

• peritrichous flagells

• catalase positive

• beta-hemolytic when grown on blood agar

• both a human and an aimal pathogen

• halophilic organism

clinical infections caused by listeria monocytogenes

• listeriosis

  • maternal disease (pregnancy)

  • neonatal disease

  • disease of immunocompromised hosts

listeriosis

• caused by literia monocytogenes

• serious infection that affects neoneates, pregnant women, and immunocomprimised hosts

maternal disease (pregnancy)

type of listeriosis

• usually occurs during the third trimester of pregnancy

• leads to miscarriage or stillbirth

• s/s: flu-like illness, fever, headache, and myalgia

neonatal disease

type of literiosis

• associated with an intauterine infection due to the aspiration of infected amniotic fluid

• it leads to meningitis that is usually seen by the third week of life

• mode of acqusition: transplacental and perinatal

disease of immunocompromised hosts

type of listeriosis

• develops through the ingestion of contaminated dairy products and processed meat products

laboratory diagnosis of listeria monocytogenes

• specimen: blood, csf, swab of lesions

• motility test: tumbling motility at RT

• culture: BAP, CAP, BHI

• biochemical tests:

  • glucose fermentation +

  • catalase +

  • urease -

  • H2S production, nitrate reduction -

management and treatment for listeria monocytogenes

• antibiotics

  • ampicillin or penicillin G

  • getamicin is often added for enhanced effectiveness, particularly for meningitis

• neonatal infections:

  • ampicillin w/ aminoglycoside (gentamicin)

legionella pneumophila

type of miscellanoeus bacteria

• gram negative

• bacillary or coccobacillary in form

• aerobic, motile

• non-carbohydrate fermenting

• major reservoirs:

  • hot water system, cooling towers, and evaporative condensers

• serogroups: 1-7; serougroups associated with LEGIONNAIRES DISEASE: 1, 4, and 6

• distinguishing chracteristics of these species:

  • they can infect and multiply within some free-living amoeba, ciliated protozoa, and biofilms

  • they can be isolated from lakes, rivers, hot springs, and mud

  • they can tolerate up to 3 mg/L of chlorinean dthus resist water treatments

  • they cannot grow on routine primary plated media like BAP

legionella pneumophila

miscellaneous bacteria

• they can infect and multiply within some free-living amoeba, ciliated protozoa, and biofilms

• they can be isolated from lakes, rivers, hot springs, and mud

• they can tolerate up to 3mg/L of chlorine and thus resist water treatments

• tehy cannot grow on routine primary plated media like BAP

clinical infections caused by legionella pneumophila

• legionnaire’s disease

  • aka legionellosis

• potiac fever

• wound abcess and encephalitis

legionnaire’s disease

• aka legionellosis, which is febrile and pneumonic illness

• mode of transmission:

  • airborne spread or inhalationof infectious aerosols

• s/s: high fever, non-productive cough, headache, neurological, and severe bronchopneumonia

legionnaire’s disease

legionnaire’s disease vs. pontiac fever

• type of illness

  • progressive pneumonia

  • 5-15% fatality rate

  • treatment required

  • highest aftality rate in health care facilities

• s/s:

  • severe pneumonia w/ chills and cough

  • muscle aches, headaches, tiredness, loss of appetite, and diarrhea

• infection rate: <5% of those exposed

• incubation: 5-10 days

• risk factors:

  • smoking and lung disorders

  • diabetes, cancer, and kindey disease

  • AIDS/HIV

  • age older than 50

  • heavy drinking

pontiac fever

legionnaire’s disease vs. pontiac fever

• type of illness:

  • flu-like illness

  • recovery in 2-5 days

  • medical treatment not necessary

• s/s:

  • fever

  • muscle aches

• infection rate: >95% of those exposed

• incubation: 36 hrs

• risk factors:

  • none known

laboratory diagnosis for legionella pneumophila

• specimen:

  • sputum and bronchoalveolar lavage

  • urine is an important specimen for antigen detection

• culture media:

  • BYCE and L-cysteine, ferric salt, and alpha-ketoglutarate

• serologic test: indirect fluorescent antibody

• rapid methods: PCR test, urine antigen test

management and treatment for legionella pneumophila

• antibiotics

  • FLUOROQUIOLONES (like levolaxacin or moxifloxacin) and MACROLIDES (e.g., azithromycin) are commonly used antibiotics for Legionnaire’s disease

  • treatment typically lasts for 1-3 weeks, with a longer duration (up to 3 eeks) sometimes recommended for severely immunocompromised pxs

mycoplasma pneumoniae

type of miscellaneous bacteria

• gram negative

• rod shaped bacteria

• lacks cell wall

• fastidious

• facultative anaerobes

cinical infection of mycoplasma pneumoniae

• primary atypical pneumonia

  • it occurs as separate incidents or as outbreaks in closed populations such as in school, military camps, and within family members

  • mode of acquisition: nhalation of contaminated aerosol droplets

  • s/s: dry cough, fever, and mild shortness of breath

laboratory diagnosis of mycoplasma pneumoniae

• specimen

  • throat swab, serum, bronchoalveolar lavage, sputum and lung tissue, urethral, vaginal or endocervical swab, blood, urine, prostatic secretions and semen

• culture: SP4 broth

• serodiagnosis: ELISA

management and treatment of mycoplasma pneumoniae

• antibiotics

  • MACROLIDES: azithromycin, clarithromycin, and erythromycin are commonly used macrolide antibiotics for mycoplasma pneumoniae infections

  • TETRACYCLINES: doxycycline is an alternative for macrolide-resistant infections, but is not recommended for young children

  • FLUOROQUINOLONES: these antibiotics may be used if other treatments fail, but are generally not recommended for children