Unit 1 Exam Bacterias Flashcards
1
Q
COVID-19 Coronavirus Disease 2019 ETIOLOGY
A
- Infectious disease in humans
- Formal name is “Severe Acute Respiratory Syndrome Coronavirus 2” , SARS-CoV-2
- Related to Virus that caused the SARS outbreak in 2003
- No public information about this virus before outbreak
2
Q
COVID-19 TYPES
A
- causes large variety of disease in humans and livestock
- known to clinically be the “common cold” (mild, self-limiting respiratory infections)
- 2002-2003” SARS-CoV emerged in China, infected 8,000, fatality of 10%
- 2012: MERS-CoV (middle eastern respiratory syndrome-CoV), 2,500 cases over 2 years, fatality of 34%.
3
Q
COVID-19 SYMPTOMS AND SEVERITY
A
- Fever, dry cough, tiredness, headaches, chills, body aches, difficulty taking a deep breath
- mild cases report runny nose or sore throat
- extreme fatigue lasts for few days or weeks
- severe cases: respiratory illnesses or organ failure
- flu-like symptoms recover in a few days
- tightness of breath resolves in another week or two
4
Q
COVID-19 PREVENTION
A
- stay home if sick and avoid sick people
- social distancing
- use a mask in public
- keep 6-foot distance from others
5
Q
COVID-19 TREATMENT
A
- treat as you would cold or flu
- Tylenol for high fevers and aches
- OTC decongestants
- fluids and rest
- NSAIDS like Advil are not recommended due to inflammatory response
- deep breathing of shower steam
- use a humidifier
- anti-malarial drugs used in India to treat high-risk patients but not in US
6
Q
Pneumococcal Pneumonia
A bacterial pathogen
Streptococcus pneumoniae
AS A DISEASE
A
- can be caused by a wide variety of microorganisms
- must be able to avoid phagocytosis or avoid killing once inside macrophages
- Mycoplasma pneumoniae is a bacteria that can cause pneumonia
- Viral pneumonia is usually but NOT always milder than bacterial pneumonia
- Fungi can also cause pneumonia
- most often in immunocompromised people
7
Q
Pneumococcal Pneumonia
ETIOLOGY
A
- Streptococcus pneumoniae: bacterial
- accounts for 40% of community acquired cases
- small, gram-positive coccus that appears in pairs
- polysaccharide capsule prevents effective phagocytosis
- blocks action of complement proteins
- causes inflammatory fluids to build up in lungs
8
Q
OTHER DISEASES CAUSED BY S. Pneumoniae
A
- ear infections
- sinus infections
- meningitis
- bacteremia
- Streptococcus species cause more microbial diseases in humans than any other microbe
9
Q
Pneumococcal Pneumonia
RISK FACTORS
A
Children:
- Under age 2
- In childcare settings
- Are immunocompromised by another infection
- With cochlear implants
Adults 19-64:
- With underlying chronic illnesses
- Immunocompromised by another infection
- In long-term facilities (nursing homes)
10
Q
Pneumococcal Pneumonia
EPIDEMIOLOGY
A
- part of the normal biota of the respiratory tract
- infection occurs when bacterium is inhaled into deep part of lungs
- factors that enhance disease: old age, season, underlying viral respiratory disease, diabetes, chronic abuse of alcohol or narcotics
- transmission is through droplet contact through respiratory secretion
11
Q
Pneumococcal Pneumonia
SYMPTOMS AND COMPLICATIONS
A
- begin with runny nose, congestion, headache, and fever
- chest pain, fever, cough, production of discolored sputum as it enters lungs
- patient appears pale and sickly
- severity and speed of onset of symptoms depends on the etiologic agent
12
Q
Pneumococcal Pneumonia
DIAGNOSIS AND TREATMENT
A
- inflammatory condition of the lung in which fluid fills the alveoli
- if invasive, blood sample or spinal tap to collect cerebrospinal fluid may be required
- if non-invasive, standard clinical examination (physical)
- treated using “broad spectrum” antibiotics
- many strands may be resistant to penicillin
13
Q
Pneumococcal Pneumonia
PREVENTION
A
- PCV13 vaccine (recommended for adults over 19 with preexisting medical conditions
- PPSV23 vaccine (recommended for adults over 19 who smoke or have asthma and is encouraged for adults over 65)
14
Q
PRIMARY AMOEBIC
MENINGOENCEPHALITIS
(PAM)
A PROTOZOAN PATHOGEN – Naegleria fowleri
A
- inflammation of the brain and spinal cord
- infection of one structure may involve the other
15
Q
PRIMARY AMOEBIC
MENINGOENCEPHALITIS
(PAM)
ETIOLOGY
A
- naegleria fowleri
- small, flask-shaped amoeba that moves by means of a single pseudopod
- rounded, thick-walled cyst
- resistant to temperature extremes and mild chlorination
- found in warm freshwater and soil
- utilize the olfactory
nerve to enter the brain - Enters the subarachnoid space
causing primary amoebic
meningoencephalitis (PAM) - Causes rapid, massive
destruction of brain and spinal
tissue
16
Q
PRIMARY AMOEBIC
MENINGOENCEPHALITIS
(PAM)
ILLNESSES AND SYMPTOMS
A
- cases are rare but are very fatal
- 4 of 133 cases in US survived
Stage 1: severe frontal headache, fever, nausea, and vomiting
Stage 2: stiff neck, seizures, altered mental state, hallucinations, and coma
17
Q
PRIMARY AMOEBIC
MENINGOENCEPHALITIS
(PAM)
DIAGNOSIS AND DETECTION
A
- Spinal tap of CSF often shows
presence of the motile amoeba - Polymerase Chain Reaction
(PCR) can detect the presence
of the DNA associated with the
amoeba - Amoeba can be cultured in the
lab or detected in the water
supply to increase effectiveness
of the two methods
18
Q
PRIMARY AMOEBIC
MENINGOENCEPHALITIS
(PAM)
TREATMENT
A
- Traditionally, only
supportive care has been
given due to the rapid
progression of the disease - Miltefosine, an anti-cancer
drug, has shown to have
anti-amoebic effects when
used with other drugs - This, along with therapeutic
hypothermia, saved a 12-year old
girl in 2013
19
Q
PRIMARY AMOEBIC
MENINGOENCEPHALITIS
(PAM)
PREVENTION AND CONTROL
A
- Infection can only occur if the amoeba
enters your nose; drinking
contaminated water has not been shown
to lead to infection - Hold nose or use nose-clips when
swimming in freshwater environments - avoid submerging your head in warm
freshwater environments - avoid
freshwater during very hot, dry seasons
-avoid stirring up sediment in freshwater
environments
20
Q
ORAL
CANDIDIASIS
(THRUSH)
A FUNGAL PATHOGEN – Candida albicans
A
- Normal biota of 50 – 100% of
humans - Mouth, GI tract, vagina
- Usually opportunistic infection
due to disruption of the normal
biota - Causes oral candidiasis within
the mouth or vulvovaginal
candidiasis
21
Q
ORAL
CANDIDIASIS
(THRUSH)
ETIOLOGY
A
- Candida albicans
- Most common
source of human
infections - Dimorphic fungus
22
Q
ORAL
CANDIDIASIS
(THRUSH)
SYMPTOMS
A
- Redness or soreness at
the site of infection - Difficulty swallowing
- Cracks at the corners of
the mouth (angular
cheilitis)
23
Q
ORAL
CANDIDIASIS
(THRUSH)
RISK FACTORS AND PREVENTION
A
- Uncommon infection in healthy adults
- Often affects immunocompromised individuals
- HIV/AIDS, cancer, autoimmune disease
- Also affects individuals with organ transplants,
diabetes, dentures, or people using
corticosteroids or broad-spectrum antibiotics
-Most easily prevented through good oral
hygiene
- Using chlorohexidine mouthwash for people
currently suffering from oral thrush is effective
24
Q
ORAL
CANDIDIASIS
(THRUSH)
DIAGNOSIS AND TESTING
A
- Easily detectable on
a wet prep - Grows in thick,
curdlike colonies on
the walls in the
mouth or throat
25
ORAL
CANDIDIASIS
(THRUSH)
TREATMENT AND OUTCOMES
- anti fungal medications
1. Clotrimazole: troches or nystatin suspensions are often used to treat mild to moderate cases
2. Fluconazole or itraconazole: required for esophageal cases or cases that persist
- Amphotericin B is required for cases that are severe or resistant
- removal of sugar and breads from the diet and adding yogurt, fermented foods, and probiotics can prevent recurrence
26
ENTEROBIASIS
(PINWORM
INFECTION)
A HELMENTHIC PATHOGEN – Enterobius
vermicularis
ETIOLOGY
Enterobius
vermicularis
Helmenthic parasite
27
ENTEROBIASIS
(PINWORM
INFECTION)
EPIDEMIOLOGY AND RISK FACTORS
- Humans are only known reservoir for
this parasite
- Most common worm disease of
children in temperate zones
- Transmission is through ingestion of
the worm’s eggs or indirectly through
contact
* Commonly found in playground sand, on
farms and in soil
* Even possible to ingest while breathing
(while mowing the yard or gardening)
* Hands, toys, bedding, clothing, toilet seats
28
ENTEROBIASIS
(PINWORM
INFECTION)
BIOLOGY (LIFE CYCLE)
- Female worms exit the
anus and lay eggs at
night
* Eggs are then ingested
by new host starting a
new cycle of infection
29
ENTEROBIASIS
(PINWORM
INFECTION)
SYMPTOMS OR SIGNS
- Pronounced anal itching,
abdominal discomfort,
difficulty sleeping
* Adult worms come outside the anus
to lay legs, which result in itching
* Secondary infections may result
from abrasions of the perianal region
from excessive scratching
-Infection is not fatal and most
cases are asymptomatic
* However, females may also
experience infection of the vaginal
canal
30
ENTEROBIASIS
(PINWORM
INFECTION)
DIAGNOSIS AND DETECTION
- Use transparent
tape to collect
eggs and
examine using a
microscope
- Done on 3 consecutive mornings after a person wakes
- Examine samples from
fingernails under a
microscope
- Look for worms in perianal
region 2 – 3 hours after the
infected person is asleep
31
ENTEROBIASIS
(PINWORM
INFECTION)
TREATMENT
- Mebendazole, pyrantel pamoate,
and albendazole
* Given as one dose and then again as a single dose 2 weeks later
* Does not reliably kill eggs, so second dose helps prevent reinfection
- Children who live on farms or
play in soil often should have
regular treatment
- Infections occurring in
households should be treated
simultaneously among all
members
32
ENTEROBIASIS
(PINWORM
INFECTION)
PREVENTION
- Proper hand washing anytime
after contact with the perianal
region is the most effective way
to prevent the infection
- Showering every morning,
especially if recovering from an
infection, is also effective
- Frequent changing of bedclothes
among infected individuals is
also recommended
33
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
Infectious Proteins! – Prions
SPONGIFORM
ENCEPHALOPATHIES
* Implicated in chronic, persistent
disease in humans and animals
* Brain tissue removed from
affected animals resembles a
sponge
34
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
ETIOLOGY
* Caused by prions
* Distinct protein fibrils deposited in brain tissue of
affected animals
* Protein composition of prions has revolutionized ideas of what can constitute an infectious agent
* Several animals are victims of similar diseases:
* Scrapies: Sheep, mink elk
* Bovine spongiform encephalopathy: cows (which is
strongly shown to be related to variant CJD in humans)
35
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
EPIDIEMIOLOGY
* 1 to 2 cases per 1 million people in US
* Exact mode of infection is unknown
* Scientists still do not know how prions replicate given that they have no nucleic acid
* Transmissible by an unknown mechanism for classic CJD or by ingesting infected meats for variant CJD
* Variant form most linked with BSE
36
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
RISK FACTORS FOR TRAVELERS
* From 1995 – August, 2006:
* UK had the highest incidence – 162 cases
* France – 20 cases
* Ireland – 4 cases
* US – 2 cases
* Canada, Italy, Japan, Netherlands, Portugal, Saudi Arabia, Spain – 1 case each
37
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
SYMPTOMS AND SEVERITY
* Affects the central nervous system of humans
* Causes gradual degeneration leading to dementia and, eventually, death
* Illness normally progresses to death within 4 -5 months for classic CJD and 13 – 14 months for variant CJD
38
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
PREVENTION
* Surveillance, culling of sick herds, and banning of high-risk materials have been very effective in countries at risk for BSE and CJD
* Avoid beef or beef products altogether when visiting countries with a history of BSE or CJD
39
CREUTZFELDT - JAKOBS
DISEASE (CJD)/
MAD COW DISEASE
TREATMENT
* Supportive care only
* No known treatments have shown any
effectiveness
