Gram Negative Bacteria - Lesture 5 Flashcards by Vanessa Forstbauer

What are four classiications of gram negative bacteria?

Cocci
Bacilli
Coccobacilli
Pleiomorphic

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What morphology is Neisseria sp?

Cocci - gram negative

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What morphology is Bordatella pertussis?

Bacilli - gram negative

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What morpology is Haemophilus influenza?

Coccobacilli - gram negative

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What morphology is Yersinia pestis?

Coccobacilli - gram negative

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What morphology is Chlamydia sp?

Coccobacilli - gram negative

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What morphology is Legionlla pneumophile?

Pleiomorphic - gram negative

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What morphology is Rickettsia sp?

Pleiomorphic - gram negative

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Give characteristics of Neisseria sp?
Morphology
Oxygen tolerance
Are the pathogens:
Catalase positive or negative?
Oxidase positive or negative?

Diplococci ‘coffee bean’ shape
Obligate aerobes
Pathogens are:
Catalase and oxidase positive

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What are two human pathogens of the Neisseria sp?

N. gonorrhoeae - gonorrhea

N. meningitidis - meningococcal meningitis

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Neisseria gonorrhoeae characteristics?

Acapsular
Many plasmids (genetic variability)
Facultatively intracellular

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What percentage of people (men/female) infected with Neisseria gonorrhoeae are asymptomatic

10% of males

80% of females

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Which bacterial infection has the following clinical features?
Purulent, foul-smelling discharge
Inflammation, dysuria, urethritis
Conjunctivitis (newborns)
Septicemia leading to endocarditis, meningitis, gonococcal dermatitis-arthritis syndrom (arthralgia, tenosynovitis, dermatitis)

Neisseria gonorrhoeae

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What is the incubation period of Neisseria gonorrhoeae?

2-14 days

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What bacterial infection has the following virulence:
No exotoxin - autolysis releases virulence factors
Lipooligosaccharide (LOS) slightly different in structure from LPS
Opa proteins:
-promote adherence
-multiple expressed by on bacterium (phase variation
Cyclical expression inhibits antibody binding and immunological memory

Neisseria gonorrhoeae

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How is Neisseria gonorrhoeae transmitted?

sexual/mucousal

Neonatal infection during birth - prenatal screening is important
Reinforcement due to lack of development of immunological memory

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What is the treatment for Neisseria gonorrhoeae?

Traditionally - Penicillin, tetracycline, ceftriaxone - increase in drug resistants require stronger/additional antibiotic approaches
Combination therapy common - ceftriasone + doxycyline
Public health monitoring of drug resistance important

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What is a sequelau of untreated gonorrhea and chlamydia in women?

Pelvic inflammatory disease

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Describe pelvic inflammatory disease including symptoms and what it can lead to if untreated

Inflammation of the uterus, fallopian tubes, ovaries
Range of symptoms but many are asymptomatic
Lower abdominal pain, fever, cervical motion tenderness, cervical inflammation
Untreated –> infertility, ectopic pregnancy, blocked fallopian tubes, miscarriage or premature birth

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What can Neisseria gonorrhoeae lead to in males?

Epididymitis that may lead to infertility

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Characteristics of Neisseria meningitidis (meningococcal disease)

Capsular - multiple serotypes based on capsular antigens (A, B, C, Y, W135)
No plasmids
Facultatively intracellular

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What bacterial infection displays the following clinical features:
Commonly asymptomatic - carries may spread pathogen via respiratory droplets
_____ septicemia leads to DIC and hemorrhage - severe skin rash (severe cases require amputation)
_____ CNS invasion leads to meningitis - fever, altered mental status, neurological symptoms (convulsions, coma)
High mortality rate if untreated
2nd most common cause of bacterial meningitis in children, adults
most common cause of bacterial meningitis in teens/young adults

Neisseria meningitidis

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What are the virulence factors of Neisseria meningitidis

Capsule - antiphagocytic

LOS - endotoxin

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How is Neisseria meningitidis transmitted?

How does the disease typically occur in a population? what serotype is in Canada?

Respiratory droplets

Disease occurs as outbreaks - serotype C in Canada

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What is the uncubation period of Neisseria meningitidis

2-10 days

What is the treatment and prevention of Neisseria meningitidis?

Vaccine for most human strains Serotype C is vaccine-preventable Treatment and hospitalization should occur immediately - drugs administered upon suspicion of infection Penicillin G, cephalosporins + supportive treatment (IV fluid, oxygen, management or intracranial pressure, etc)

Characteristics of Bordatella pertusis (Whooping cough)

Gram negative coccobacillus, appears singly or in pairs Colonizes URT and alveolar macrophages, leading to invasion Pertussis toxin an important virulence factor

What bacterial infection has the following clinical features: Early (catarrhal) stage - fever, mild coughing, sneexing, or runny nose, which increase in intensity (~10 days) Late (paroxysmal) stage - uncontrollable fits, each with five to ten forceful coughs, followed by high-pitched "whoop" (~2-8 weeks or longer)

Bordatella pertusis

How is a diagnosis made of Bordatella pertusis?

Clinical symptoms and culture from nasal swab

How is Bordatella pertusis transmitted?

highly contagious by contact and respiratory droplets

What is the incubation period of Bordatella pertusis

5-20days

what is the treatment of Bordatella pertusis

Only effective at catarrhal stage Macolide antibiotics administered to prevent complications Vaccine available (pentavalent or DTP)

Characteristics of Haemophilus influenza (bacterial influenza)

Gram negative coccobacillus Encapsulated (a-f) and non-encapsulated strains Most serotypes are OPPORTUNISTIC pathogens

What are the most pathogenic strains of Haemophilus influenza?

H.influenza serotype b (Hib) and non-typable Hi (NTHi) strains most pathogenic

What bacterial infection has the following clinical features: Surface infections mild/asymptomatic Invasive infections may cause pneumonia, bronchitis

Haemophilus influenza

Which strain is responsible for 95% of invasive Haemophilus influenza infections?

Hib

What are potential complications of Haemophilus influenza infections?

Epiglottitis Meningitis Bacteremia Septic arthritis

How is Haemophilus influenza infection diagnosed?

Culture (from sterile body site), agglutination test

How is Haemophilus influenza infection transmitted?

Transmitted via direct contact, contaminated surfaces

What is the incubation period of Haemophilus influenza

unknown - estimated to be 2-10 days

What is the treatment for Haemophilus influenza?

Hib vaccine available (pentavalent vaccine) | Cephalosporins for severe infection, penicillins + b-lactamase inhibitors for milder infection

Characteristics of Yestinia pestis (plague)

'Black death' Gram negative coccobacillus Facultative anaerobe

Which bacterial infection has the following clinical features: Bubonic plague Pneumonic plague Septicemic plague

Yestinia pestis

Describe the bubonic plague as caused by Yestinia pestis

Sudden fever, chills, weakness, headache | Swollen lymph nodes (buboes"

Describe the pneumonic plague as caused by Yestinia pestis

Fever, chills, chest pain | Cough, respiratory distress, bloody or watery mucous

Describe the Septicemic plague as caused by Yestinia pestis

Fever, chills, extreme weakness Multiorgan hemorrhage, vasculitis May result from bubonic or pnuemonic plague

How is Yestinia pestis diagnosed?

Identification of clinical features (buboes), lab testins from infected tissue including blood or lymph

How is Yestinia pestis transmitted?

Bubonic - vector-borne (fleas) Pneumonic - respiratory droplets Transmission from infected animals, contaminated water

What is the incubation period of Yestinia pestis

2-6days

What is the treatment/prevention of Yestinia pestis

Mortality rate high unless treated early Strptomycin, chloramphenicol tetracycline, flouroquiones

Characteristics of Chlamydia sp?

Gram negative coccobacilli Obligate intracellular bacteria Elementary body infective, reticulate body replicative Replicative from bacterium replicates intracellularly in reticulate bodies/inclusion bodies (replicates by binary fission for 1-3wks in a host cell) Bacteria exocytosed from host cell as an elementary body

What are the two human pathogens of Chlamydia sp?

Chlamydia trachomatis | Chlamydia pneumoniae

What bacterial infection shows the following clinical presentation: Urogenital infection: one of the most common STIs in North America Painful urination, increasing discharge In women - pain/bleeding during/after sex, bleeding between periods Rectal infection - discomfort, pain, bleeding, discharge Oral infection typically asymptomatic, despite shedding Infection in the eye may lead to conjuctivitis

Chlamydia trachomatis

What percentage of people (men/women) infected with Chlamydia trachomatis are asymptomatic?

50% of males | 80-90% of females

What are some complications of Chlamydia trachmatis infections in men? in women?

Men - epididymitis, rectitis, non-gonococcul urethritis | In women - pelvic inflammatory disease (untreated)

How is Chlamydia trachomatis transmitted?

mucosal (sexual)

What is the incubation period of Chlamydia trachomatis?

poorly defined 2-3 weeks or longer

What is the treatment of Chlamydia trachomatis?

doxycycline, azithromycin

Describe trachoma infection (serovars A, B, BA & C)

Infection of the eye - leading cause of infectious blindness | Associated with poor sanitation, hygiene, water, and is a major disease of developing areas

How is trachoma infection (serovars A, B, BA & C) spread?

Spread by eye discharge (contact, clothing...) and eye-seeking flies (mechanical vector)

What can trachoma infection (serovars A, B, BA & C) lead to?

Corneal scarring, blindness

What is the incubation period of trachoma infection (serovars A, B, BA & C)

7-12 days

What is the treatment for trachoma infection (serovars A, B, BA & C)

tetracycline, azithromycin

How is chlamydia pneumonia transmitted?

Respiratory secretions

Which bacterial infection is described in the following: Most people are exposed to pathogen by adulthood - often asymptomatic Causes mild bronchitis/pneumonia in children, more sever invasive disease in adulthood (community acquired pneumonia aka CAP) Often associated with mixed infections

chlamydia pneumonia

Which bacterial infection has the following clinical features: Mild, URT symptoms or no symptoms in most cases Severe cases progress to LRT infection 1-4wks collowing exposure Persistent cough, malaise, headache a common distinguishing feature Fever early in infection, absent during clinically relevant stage

chlamydia pneumonia

What is the treatment for chlamydia pneumonia?

If needed doxycycline and related are used

How is chlamydia pneumonia related to atherosclerosis?

INcreased incidence of seropositivity in patients with atherosclerosis Isolation of bacteria from atherosclerotic lesions Induction of atherosclrotic plaques in animal models of infection Activation of ROS - damage, inflammation, remodeling

Characteristics of Legionella pneumophile (Legionnaires' disease)

Gram negative pleiomorphic | Contaminated water breeds bacterial growth - water cooler towers, air conditioning systems, plumbing systems

Which bacterial infection has the following clinical features: fever, chillis, cough Muscle aches, headache, fatigue, ataxia (loss of coordination), diarrhea, vomiting Pontiac fever less severe, resembles acute influenza virus infection, resolves spontaneously

Legionella pneumophile

What are potential complications of Legionella pneumophile

Respiratory or renal failure | Sepsis

How is Legionella pneumophile transmitted?

Transmission via aerosol, water (associated with poor ventilation and water treatment facilities - hotels, hot tubs, factories, nursing homes) Not spread from person to person

What is the incubation period of Legionella pneumophile?

2-10 days

What are the treatments for Legionella pneumophile?

Quinolones, macrolides, tetracyclins

What are characteristics of Rickettsia sp?

Gram negative aerobic, pleiomorphic Obligate intracellular parasite Typhus, rocky mountain fever, rickettsialpox Vector-borne infection R. prowazekii source of eukaryotic mitochondria

How is Rickettsia typhi (Typhus) spread?

Spread by lice feces

Which bacterial infection is described as: high fever, cough, chest rash, severe muscle pain Dermal leasions 5-6dpi, chest and spreading to the rest of the body Severe vasculitis and increased vascular permeability - leads to shock, acute respiratory distress

Rickettsia typhi (Typhus)

How is Rickettsia diagnosed?

Multiple criteria including exposure, history, clinical preenstation and serology

What is the incubation period of Rickettsia?

5-10 days

What is the treatment for Rickettsia?

Doxycycline, chloramphenicol

Gram Negative Bacteria - Lesture 5 Flashcards

(80 cards)