Microbio: Module 6 - Bacterial Diseases

Healthcare Associated Infection (HAI)

Infections that patients acquire while they are receiving health care for another illness

Catheters, Surgeries, Injections, Antibiotic use/abuse, Infections and Diseases from healthcare workers, Improper cleaning and disinfection of healthcare facilities

Identify factors that raise a patient’s risk of developing HAI

Bloodstream infections, C.diff infections, Methicillin-resistant Staphylococcus aureus (MRSA) infections, Surgical site infections, Urinary tract infections

List the common HAIs that patients develop most

S. maltophilia, P. aeruginosa, a. baumanii, b. cepacia, and c. enterobacteroaceae

The gram (-) bacteria causing the most HAIs include:

Environmental microbe commonly found in water

Reservoir in Stenotrophomonas maltophilia

Causes a variety of infections, but most commonly causes pneumonia in patients with chronic lung diseases

Infection Type in Stenotrophomonas maltophilia

Leads to death in 14% to 69% of patients

Statistics in Stenotrophomonas maltophilia

Naturally resistant (intrinsic) to many broad spectrum antibiotics and forms biofilms (especially on plastics)

What are the unique characteristics of Stenotrophomonas maltophilia?

Hospital water sources, tap water, sinks, drains, toilets, showers

Reservoir in Psuedomonas aeruginosa or P. aeruginosa

Exposure to contaminated water or soil and contaminated hands, equipments, or surfaces in hospital setting

How is it spread in Psuedomonas aeruginosa

Blood, lungs, (pneumonia), or other parts of the body

Infection type in Pseudomonas aeruginosa

Caused 32,600 infections in hospitalized patients and 2,700 deaths in the US in 2017

Statistics in Pseudomonas aeruginosa

Environment like soil and water

Reservoir in Acinetobacter Baumanii

Person to person via contact with contaminated surfaces or equipment and direct person to person spread via contaminated hands

How is it spread in Acinetobacter Baumanii or A. baumanii

Blood, lungs (pneumonia), wounds, urinary tract, soft tissue

Infection Type in Acinetobacter Baumanii

Patients in healthcare settings, especially with those on breathing machines, with catheters, with wounds from surgery/burns, are in ICU, and have prolonged hospital stays

Who’s at risk in Acinetobacter Baumanii

Worldwide - 20% of ICU infections and caused an estimated 8,500 infections in hospitalized patients and 700 estimated deaths in the US in 2017

Statistics in Acinetobacter Baumanii

Normal flora of human intestine, human stool

Reservoir in Klebsiella pneumoniae

Person to person via contaminated hands of healthcare personnel or other persons, less commonly by contamination of the environment/equipment, not spread through the air

How is it spread in Klebsiella pneumoniae

Pneumonia, bloodstream infections, wound/surgical site infections, meningitis

Infection Type in Klebsiella pneumoniae

Patients in healthcare settings, especially those on breathing machines (ventilators), with intravenous catheters, on long courses of antbiotics

Who’s at risk in Klebsiella pneumoniae

Carbapenem-resistant Enterobacteriaceae

Klebsiella pneumonia is an example of which HAI?

Who’s at risk in Staphylococcus aureus?

Normal flora of human nose and skin

Reservoir in Staphylococcus aureus or S. aureus

Sepsis when it spread to the bloodstream, pneumonia, endocarditis, osteomyelitis, localized skin infections (pimples, abscesses), impetigo

Infection type in Staphylococcus aureus

119,247 S. aureus bloodstream infections with 19,832 associated deaths occurred

Statistics in Staphylococcus aureus

Human immune system and system of surveillance

What are the two types of protection we have against food/waterborne infections?

1. Wash hands frequently

2. Cook raw beef and poultry products thoroughly

3. Avoid unpasteurized milk and juices, any food from unpasteurized milk

4. Properly wash food utensils, cutting boards, and raw fruits and vegetables (including kitchen sponges)

5. Beware of “double dippers”

6. Avoid eating at disreputable joints

7. Do not eat raw shellfish

8. Avoid food and drinks sold by street vendors (especially abroad)

9. Do not share eating utensils, water bottles, etc.

10. Do not swim in contaminated waters

What are the “10 Commandments” for reducing foodborne illness. (Understand these)

Food intoxication is ingestion of already-produced bacterial toxins, bacteria may no longer be present, and enterotoxin is responsible for food poisoning symptoms whereas foodborne infection is a result of the ingestion of bactera-contaminated foods and subsequent bacterial growth in the intestinal tract, secretion of toxins and possible invasion of intestinal tract

Differentiate between food intoxication and foodborne infection.

Intoxication as it is the most common type of food poisoning

Infection type (Intoxication vs. Infection) in Staphylococcus aureus: Foodborne

Normal flora of human nose and skin

Source of contamination/Reservoir in Staphylococcus aureus

Transmitted from people infected with S. aureus (usually via infected skin source) into food

How it’s spread in Staphylococcus aureus: Foodborne Illness

Foodborne infection that causes salmonellosis

Infection type (Infection vs. intoxication) in Salmonella

Animals

Source of contamination/Reservoir in Salmonella

Infection

Infection type in Vibrio Cholerae (Infection vs. Intoxication)

By air droplets or fomites

How are bacterial respiratory infections generally transmitted?

Upper respiratory infections affect the airways above the vocal cords, including the nose, sinuses and throat whereas lower respiratory infections involve the trachea, airways and lungs; URIs are generally mild and viral whereas LRIs are deeper, more severe, and can be caused by bacteria, viruses or fungi

Distinguish between upper vs. lower respiratory infections. 

Whooping cough (pertussis)

Airborne Bacterial Diseases: Infection type in Bordetella Pertussis

18,975 cases in US in 2017 and 24.1 million cases worldwide/160,700 death in children younger than 5

Airborne Bacterial Diseases: Statistics in Bordetella Pertussis

Infected children, no non human reservoir

Airborne Bacterial Diseases: Reservoir in Bordetella Pertussis

Infants and children younger than 4 years of age

Airborne Bacterial Diseases: Who’s at risk in Bordetella Pertussis

Coughing, talking, sneezing, laughing

Airborne Bacterial Diseases: How it spreads in Bordetella Pertussis

Strep throat, scarlet fever, toxic shock syndrome, necrotizing fasciitis

Airborne Bacterial Diseases: Infection type in Streptococcal Infections

650-850 cases of necrotizing fasciitis per year in US (1 in 5 die)

Airborne Bacterial Diseases: Statistics in Streptococcal Infections

Human nose and throat

Airborne Bacterial Diseases: Reservoir in Streptococcal Infections or Streptococcus Sp.

Infants and children younger than 4 years of age

Airborne Bacterial Diseases: Who’s at risk in Streptococcal Infections

Respiratory droplets, contact with wounds/sores on skin

Airborne Bacterial Diseases: How it spreads in Streptococcal Infections

Inflammation of the meninges

Airborne Bacterial Diseases: Infection Type in Bacterial Meningitis

Between 2003-2007 - 4,100 cases and 500 deaths in the US

Airborne Bacterial Diseases: Statistics in Bacterial Meningitis

Human nose and throat, no animal reservoir

Airborne Bacterial Diseases: Reservoir in Bacterial Meningitis or N.meningitides and HiB

Infants and children younger than 4 years of age and college students living in dorms

Airborne Bacterial Diseases: Who’s at risk in N.meningitides and HiB (Bacterial Meningitis)

Respiratory droplets from carriers and infected individuals

Airborne Bacterial Diseases: How it spreads in Bacterial Meningitis or N. meningitides and HiB

Sexually Transmitted Infection

Refers to any infection passed from one person to another through sexual contact, including vaginal, oral, or anal sex

Vaginal or anal intercourse, oral sex, semen and vaginal discharges major sources

Identify factors that raise a patient’s risk of developing an STI

Bacterial infection

STIs: Infection Type for Treponema Pallidum or Syphillis

in 2016, more than 27,814 cases if primary/secondary syphilis and 628 cases of congenital syphilis

STIs: Statistics for Treponema Pallidum or Syphillis

Humans

STIs: Reservoir for Treponema Pallidum or Syphillis

Sexual contact, mother to child via placenta, rarely via saliva

STIs: How it spreads for Treponema Pallidum or Syphillis

Frequently coinfects with other STIs, including HIV/Aids and has three stages

STIs: Unique characteristics for Treponema Pallidum or Syphillis

Primary, Secondary Tertiary

What are the 3 stages Syphilis?

Primary (Syphilis)

Manifested by appearance of painless chancres on penis or cervix

Secondary (Syphilis)

Appearance and disappearance of rash over 5 year period and is systemic

Tertiary (Syphilis)

Organs and tissues (especially cardiovascular and nervous system) degenerate

Bacterial sexually transmitted infection

STIs: Infection Type for Neisseria Gonorrhoeae or Gonorrhea

Second most common STI in US after Chlamydia; in 2015-2016 rate of reported gonorrhea cases increased by 22.2% among men and 13.8% among women

STIs: Statistics for Neisseria Gonorrhoeae or Gonorrhea

Pili enable bacteria to attach to lining of urethra and can hang on during passage of urine; carriers can often remain without symptoms; on list of superbugs

STIs: Unique Characteristics for Neisseria Gonorrhoeae or Gonorrhea

Humans

STIs: Reservoir for Neisseria Gonorrhoeae or Gonorrhea

Sexual contact and mother to child during delivery

STIs: Transmission/Spread for Neisseria Gonorrhoeae or Gonorrhea

Bacterial sexually transmitted infection

STIs: Infection Type for Chlamydia Trachomatis

Most common STI; in 2016, 1,598,354 reported cases in US

STIs: Statistics for Chlamydia Trachomatis

People often are unaware that they are infected: 70% of females and 30% of males lack symptoms and it is an obligate intracellular parasite

STIs: Unique Characteristics for Chlamydia Trachomatis

Humans

STIs: Reservoir in Chlamydia Trachomatis

Sexual contact and mother to child

STIs: Transmission/Spread for Chlamydia Trachomatis

Bacteria infection of the gastrointestinal tract

Infection Type for Helicobacter pylori (H. Pylori)

Common, 70% of population in developing countries, 30 to 40% of population of US and other developing countries, and only 10% develop ulcers

Statistics for Helicobacter pylori (H. Pylori)

Suspected to be oral cavity of humans

Reservoir for Helicobacter pylori (H. Pylori)

Unknown but likely person to person and possible food or water contamination

Transmission/Spread for Helicobacter pylori (H. Pylori)

Produces the enzyme urease which breaks down urea into ammonia and CO2, ammonia neutralizes stomach acid and it allows bacteria to survive acidic environment in stomach; it can be diagnosed with breath test (detects urease) and can be cured in 2-3 weeks with appropriate antibiotics

Unique Characteristics for Helicobacter pylori (H. Pylori)

Non-communicable bacterial infection

Infection Type for Clostridium Tetani or Tetanus

30 cases per year in US, 5 deaths and nearly all cases in people who haven’t received a vaccine or booster

Statistics for Clostridium Tetani or Tetanus

Soil, manure, dust and normal inhabitants of intestinal tracts in horses and cattle

Reservoir for Clostridium Tetani or Tetanus

Exposure to endospore of C.tetani through open wound; usually puncture wounds that do not tend to bleed a lot

Transmission/Spread for Clostridium Tetani or Tetanus

Produces tetanospasmin which is a neurotoxin that interferes with muscle contract and there are several vaccines available: DT, DTaP, Td, and Tdap

Unique Characteristics for Clostridium Tetani or Tetanus

Contact Disease

Is an infectious illness spread through the transfer of pathogens (like bacteria, viruses or fungi) from an infected person, animal, or contaminated surface to a healthy individual

Soilborne Disease

Is any illness in plants or humans caused by pathogens (like fungi, bacteria, viruses, or parasites) that naturally persist, survive, or travel within the soil

Arthropod Borne Bacterial Disease

Is an illness caused by pathogenic bacteria that are transmitted to humans or animals through the bites of infected arthropods, such as mosquitoes, ticks, fleas, and lice

Environmental exposure, human behavior, vector biology, and individual susceptibility

Identify factors that raise a patient’s risk of developing an arthropod borne disease

Severe bacterial infection and is a reemerging infectious disease

Arthropod-Borne disease: Infection Type for Yersinia Pestis or the Plague

Average of 7 cases reported annually in US and in 2010 - 2015, 3,248 cases with 584 deaths worldwide and the mortality rate in untreated cases is 50%

Arthropod-Borne disease: Statistics for Yersinia Pestis or the Plague

Highly virulent and it only takes a single bacterium to establish an infection

Arthropod-Borne Disease: Unique Characteristics for Yersinia Pestis or the Plague

Zoonotic, 200 species of mammals such as gophers, ground squirrels, mice, wild rats

Arthropod-Borne Disease: Reservoir for Yersinia Pestis or the Plague

Flea bite, pneumonic (respiratory droplets and saliva), septicemic (direct contact of contaminated hands, food, or objects with mucous membranes of nose/throat)

Arthropod-Borne Disease: Transmission/Spread for Yersinia Pestis or the Plague

Bacterial infection

Arthropod-Borne Disease: Infection Type for Borrelia Borgdorferi or Lyme Disease

Most common vector-born disease in US and 30,000 cases reported to CDC but estimated that there are closer to 300,000

Arthropod-Borne Disease: Statistics for Borrelia Borgdorferi or Lyme Disease

Complicated life cycle and vector is deer tick

Arthropod-Borne Disease: Unique Characteristics for Borrelia Borgdorferi or Lyme Disease

Zoonotic, squirrels and white-footed mouse

Arthropod-Borne Disease: Reservoir for Borrelia Borgdorferi or Lyme Disease

Arthropod - Tick bite

Arthropod-Borne Disease: Transmission/Spread for Borrelia Borgdorferi or Lyme Disease

Vector-borne zoonotic infection

Arthropod-Borne Disease: Infection Type for Rickettsia Rickettsii or R.rickettsiae

In 2017, there were 6,248 cases and 5-10% were fatal

Arthropod-Borne Disease: Statistics for Rickettsia Rickettsii or R.rickettsiae

Early treatment with Doxycycline is key and prevent illness by preventing tick bites

Arthropod-Borne Disease: Unique Characteristics for Rickettsia Rickettsii or R.rickettsiae