Germs Test 2

Spontaneous Generation

Living organisms and life arose from nonliving matter

Louis Pasteur

From Paris Academy of Sciences, his 1858 experiment showed pasteurization with bend (No growth) vs no bend (growth) in glass

Pasteurization

A method that heats food to kill pathogenic bacteria without ruining the flavor, some bacteria survive

Life From Life

Bacterial growth required exposure to bacteria

Miasma Theory

Ancient origins; disease caused by bad air from rotting/illness, encouraged sanitation

Germ Theory

Microbe life can cause disease, act as pathogens, a less accepted but competing idea

Pathogen

An organism that has potential to cause disease to the host

Robert Koche

Founded Koche’s Postulates, which contributed to Germ Theory

Koche’s Postulates

1. Microbe must be found in all cases of disease

2. Microbe must be isolated and cultured in the lab

3. Microbe must cause the disease when introduced to an uninfected host

4. Microbe must be isolated from the new diseased host

Stomach Ulcers

Caused by Helicobacter pylori bacteria, spreads via oral-fecal body fluids, infects 50-75% of all people

Ulcer

An open wound that fails to heal

Common Pathogens

1. The common cold (rhinoviruses)

2. Gingivitis (S. mutans + P.gingivalis)

3. Strep Throat (S.pyogenes)

Common Cold

Caused by many major viral groups, over 50% of cases from Rhinoviruses

Common Cold Transmission

Spread via aerosolized droplets from respiratory track and contact with contaminated surface and mucous membrane

Common Cold Infection & Symptoms

Last 7-14 days, include: sore throat, runny nose, coughing, sneezing, headache, tiredness

Common Cold Treatment & Prevention

Most cases resolved by 2nd + 3rd levels of immune defense, social distancing, hand washing, and masks may help although not extensively studied in Rhinoviruses

Gingivitis

Bacteria, Streptococcus mutans and Porphyromonas givgivalis, infesting gingival crevice and creating biofilms that cause plaque

Gingivitis Transmission

S. mutans and P. gingivalis are part of our microbiome, can also be spread from infected individuals via saliva

Gingivitis Infection & Symptoms

Bleeding gums, pockets further enabling bacterial infection

Gingivitis Treatment & Prevention

Can be reversed if not too extensive through removal of plaque and biofilm buildup, regular disruption of biofilm from brushing, flossing, and dental cleaning

Strep Throat

Caused by Streptococcus pyogenes, a group A streptococcus, highly adapted to living in humans

Strep Throat Transmission

Spread via aerosolized droplets from respiratory system, highly contagious and most common in kids. not contagious 24-48 hours after antibiotic treatment

Strep Throat Infection & Symptoms

White streaks on tonsils, red patches, painful and inflamed throat, fever

Strep Throat Treatment & Prevention

identified on blood agar plates then reduced via antibiotics, isolate until antibiotic treatment

Household Pathogens

1. Tinea

2. Black Mold

3. Serratia

Tinea

Caused by Dermatophytes (9 genera of multicellular fungi), include Athletes Foot, Jock Itch, and ringworm on body

Tinea Transmission

Spread vi direct contact with mycelium or specialized spores from humans, animals, or the environment, potentially by clothing, body hair, or surface contact

Tinea Infection & Symptoms

Hyphae and specialized spored (arthroconidia) grow on epidermis, red, rash-like skin which may appear in a ring, inflamed and hyper-sensitive skin that hurts to touch

Tinea Treatment & Prevention

Primarily anti-fungal creams/drugs, limit public exposure when infected

Black Mold

Caused by Stachybotrys chartarum, favors damp/waterlogged habitats, feeds on the plant product cellulose

Black Mold Transmission

Homes with sufficient moisture and warm temps enable mycelium growth, spreading of spores

Black Mold Infection & Symptoms

Not intentionally a human pathogen, caused by respiratory reactions to released spores and organic compounds. Sneezing, coughing, congestion, eye irritation

Black Mold Treatment & Prevention

Removing with anti-microbial cleaners, removing old food source (decaying, damp wood/plant-based products), reduce home moisture levels, address water damage

Serratia

Caused by Serratia marcescens bacterua that consume phosphorous-based substances (soaps and shampoos), favors damp environments

Serratia Transmission

Regularly grow on grout, tiling, curtains, etc. in bathrooms around sinks or drains

Serratia Infection & Symptoms

Generally not a risk, can be issue if internalized in bloodstream via catheters, IVs, needles

Serratia Treatment & Prevention

Antibiotics, although resistance is an issue, prevented by bleach and other conventional household cleaners

Waterborne Pathogens

1. Crypto (Cryptosporadium parvum)

2. Giardia (Giardia lamblia)

Crypto (Cryptosporidiosis)

Caused by Cryptosporidium parvum, single-celled eukaryote common in bodies of untreated water, has a high chlorine tolerance

Crypto Transmission

Fecal contamination (both cow and human waste are major spreaders)

Crypto Infection & Symptoms

Burrows into mucous membrane of small intestine, cleared out by immune system defenses in 1-2 weeks if healthy, causes extensive, watery diarrhea

Crypto Treatment & Prevention

Generally by immune defense, clean water to prevent dehydration from diarrhea, prevented by clean drinking water

Giardia (Giardiasis)

Caused by Giardia lamblia, single-celled eukaryote often in bodies of water that contain aquatic wildlife

Giardia Transmission

Fecal-oral contamination, swimming and swallowing water from lakes or ponds, bever ponds are a prominent source

Giardia Infection & Symptoms

1-2 weeks incubation, diarrhea 2-5x per day for 10+ days, abdominal pain, gas, bloating, vomiting and weight loss, lasts 2-6 weeks

Giardia Treatment & Prevention

Generally left up to immune defense, anti-patristics, clean water to prevent dehydration from diarrhea, avoiding swallowing untreated water from ponds/lakes

Foodborne Pathogens

1. Food molds

2. Listeria (food) Poisoning (Lysteria monocytogenes)

3. Food Poisoning (E. coli)

4. Salmonella (food) poisoning (Salmonella typhi/typhimurium)

Food Molds

Many species, such as penicillin, often affect humans through irritation/allergies to spored or mycotoxins released from hyphae

Food Molds Transmission

Fungal spore ubiquitous in air, porous, moist food at warmer temps

Food Molds Infection & Symptoms

Various illnesses based on species, from mild upset/food poisoning to cancer

Food Mold Treatment & Prevention

No treatment, dispose of any food with indications of mold, reducing moisture and keeping food at colder temps, preservatives

Listeria Poisoning

Caused by Listeria monocytogenes, can cause severe and potentially deadly food poisoning, 3rd leading cause of US foodborne deaths

Listeria Poisoning Transmission

Normally found in soil, spread between people via fecal-oral contamination, often improperly treated or contaminated dairy, mean, produce

Listeria Poisoning Infection & Symptoms

2-4 week incubation, infects intestines and possible into tissues by piercing through cell membrane, diarrhea, vomiting to flu-like symptoms, stiff neck, seizures, confusion, loss of balance

Listeria Poisoning Treatment & Prevention

Immune system if not severe, antibiotics for severe cases, follow basic hand-washing procedures and wash, separate, cook, chill protocols

Food Poisoning

Disease caused by consuming pathogenic microbes

Food Poisoning Infection & Symptoms

Diarrhea, stomach pain/cramps, nausea, vomiting, fever

Food Poisoning Treatment & Prevention

Clean, Separate, Cook, and Chill, washing utensils, produce, and hands, cook animal products to proper temp

Salmonella Poisoning

Caused by Salmonella typhimurium and Salmonella Typhi, several species cause disease and food poisoning in different ways, most common US food poisoning and related death

Salmonella Poisoning Transmission

S. Typhimurium often zoonotic from animal feces, S. Typhi via oral-fecal contamination between humans

Salmonella Poisoning Infection & Symptoms

Inhabit small intestine, develop in 12-72 hours, standard food poisoning symptoms, possible bloody diarrhea, lasts 4-7 days.

Typhoid Fever

Caused by S. typhi, where bacteria inhabit small intestine, but also travels to liver and spleen, symptoms include food poisoning, rash on body/stomach, delirium & convulsions

Salmonella Poisoning Treatment & Prevention

Generally delt with by immune system, antibiotics used in severe cases, wash hands after handling at-risk animals, standard wash, separate, cook chill protocols

E. Coli Poisoning

2nd most common cause of food poisoning, over 700 strains with 6 being the main causes

E. Coli Poisoning Transmission

Most of 6 species directly via human feces, 1 via cattle feces

E. Coli Poisoning Infection & Symptoms

Various parts of gastro-intestinal tract, most outbreaks due to “shiga toxin”, general food poisoning symptoms

E. Coli Poisoning Treatment & Prevention

Dealt with by immune system, blood or urinary use antibiotics, following proper hand-washing and wash, separate, cook, chill procedures

Desiccation

Dehydrating cells; can preserve foods while killing pathogens, endospores and fungal spores may be preserved

Clinical Microbiology

The study of microbes to diagnose and treat pathogenic diseases, must accurately obtain pathogens

Culturing

Growing pathogens; required pathogens to be kept at optimal temperatures in a nutritional medium

Agar

a Jello-like extract of seaweed used to culture many bacteria

Colony

A visible cluster of bacteria derived from 1 cell

Sequencing

After culturing, microbes are examined in multiple ways (shape, metabolism, gram stain cell wall) for diagnosis

Eosin Methylene Blue (EMB) Plate

Dark red/purple, semi transparent. Key for detecting fecal based microbes based on lactose metabolism, purpleish border=fecal-based bacteria, clear colonies = non-fecal bacteria

Blood Agar Plate (BAP)

Color from sheep blood, opaque. key for detecting microbes that can rupture blood cells, Alpha (mild cell rupture, green) Beta (complete rupture, no red around) and gamma (cannot rupture)

Epidemiology

The tracking and analysis of pathogenic disease distribution patterns, two major focal points are Surveillance and identifying key trends from surveillance

Sporadic

Pathogen reported at irregular intervals at random locations

Endemic

Pathogen as steady frequency over a long period of time in a specific location

Epidemic

Prevalence of pathogen increases over a sporadic or endemic rate

Pandemic

Multiple epidemics across multiple continents

Dr. John Snow

Attempted to identify the source of the cholera outbreak in London in 1854, used epidemiology and ended the outbreak by finding the right water pump

Cholera

Caused by Vibrio cholera, ingested from fecal contamination in water (or food)

Cholera Transmission

Through fresh/saltwater; some live with shellfish, ingested from fecal contamination in water or food

Cholera Infection & Symptoms

1-5 day incubation, infects the small intestine and causes water and electrolytes to flow out of intestinal cells, 10-20 liters of water diarrhea per day, 50-60% rate of death within hours via dehydration

Cholera Treatment & Prevention

Rehydration Therapy (water + glucose + electrolytes), bacteria flushed out of system, antibiotics can help, modern water treatment services

Alexander Flemming

Discovered mold (Penicillin) that killed microbes when studying staphylococci bacteria in 1928

Antibiotic

“Anti-life” toxin that killed bacteria and only bacteria, metabolic by-product of fungal and bacterial microbes

Main Misuses of Antibiotics

1. Doctors giving when not needed

2. Patient using when not needed or not fully using amount prescribed

3. Extensive livestock preventative use

These mean more bacterial cells are regularly exposed to antibiotics and develop antibiotic resistance

Antibiotic Resistance

When bacteria are no longer affected by previously effective antibiotic

Plasmids & Conjugation

How Bacteria Share Antibiotic Resistance Traits

Opportunistic Infections

When microbes find an immune weakness and become pathogenic

Methicillin-resistant Staphylococcus aureus (MRSA)

Resists methicillin, numerous strains also resist other antibiotics

Vancomycin Resistant Enterococci (VRE)

Vancomycin antibiotic a strong response to methicillin and related resistances, some species have become resistant (including MRSA’s)

Enterococci

bacteria common in out intestines, mouths, and female genital tract, opportunistic; serious infections often from major injuries, surgeries, or other hospital procedures

Smallpox

Caused by Variola virus, one of the most deadly human pathogens (about 30% average fatality rate, 3-4 million deaths per year)

Smallpox Transmission

Airborne due to viral load in mouth and contact due to infected skin cells

Smallpox Infection & Symptoms

7-19 day incubation, mostly through upper respiratory system, fever, aches, vomiting, sores in mouth and rash on all skin, scabs

Smallpox Treatment & Prevention

No known treatment, vaccine

Edward Jenner

Pioneered the first vaccination attempt, removed sore from a milkmaid with cowpox and put in in an 8-year-old, then inoculates 8-year-old with smallpox sore and had no ill impact

How Vaccines Work

Mimic antigens for the third defense to learn how to attack