MICROBIOLOGY UNIT 4 PATRICIA LONGORIA

catalase test

Test that determines whether or not bacteria has "catalase" enzyme.

Coagulase test

a test in which organisms are mixed with plasma on a slide. if the cells clump together, the culture is coagulase positive

skin defenses

keratinized layer, sloughing, low pH, high salt, antimicrobial peptides, sebum from sebaceous glands

keratin

hard protein material found in the epidermis, hair, and nails

sebaceous oil glands

scent glands associated with the hair follicle

integument

the skin together with the hair, nails, and sweat and oil glands

normal biota on healthy skin

streptococcus, staphylococcus

propionibacterium, corynebacterium, pseudomonas, lactobacillus, candida (yeast)

maculopapular rashes

Flat to slightly raised colored bumps on the skin

Rubeola-Measles

measles virus

respiratory droplet transmission

humans are the only living reservoir for this virus

symptoms: sore throat, dry cough, headache, conjunctivitis, lymphadenitis, fever, Kopliks spots

characteristic exanthem (widespread rash, begins on the head to the rest of the body)

defective, dormant measles virus can stay in a person's body and can move toward neurons and invade the brain; can remain years after measles has cleared

Rubeola-Measles virulence factors

syncytium formation, ability to suppress CMI

the virus implants the respiratory mucous and infects the tracheal and bronchial cells. it then travels to the lymphatic system leading to viremia

Rubella

caused by the rubella virus

moderately communicable through respiratory secretions and urine droplets in close living conditions.

has 2 clinical forms

postnatal rubella

caused by rubella virus

rash on the face, spreads to the body

aka: "3 day measles"

joint pain

congenital rubella

fetus is born already infected with rubella

strongly teratogenic: can cross placenta and infect the baby in utero

severe

miscarriage

sequelae: deafness, cardiac abnormalities, mental/ physical retardation

Fifth disease (erythema infectiosum)

human parvovirus B19, a strain of the dog virus "parvo"

mild "slapped-cheek" rash, low fever, fatigue, runny/ stuffy nose

spread through respiratory secretions

very contagious with no treatment, usually mild

the rash of this disease may reoccur for several weeks and may be brought on by any activity that increases body heat

Roseloa (sixth disease)

human herpesvirus 6 (HHV-6)

common in young children/ babies

high fever (105F) seizures

rash, last symptom, after 4th day; only about 30% even develop a rash

pustular rashes

rashes with lesions that contain fluid

smallpox

variola virus

droplet transmission or bedding/ clothing

2 forms: variola minor, variola major

last natural cause in 1977

class A bioterrorism agent: easily disseminated, high mortality rate, incite panic, require preparedness

rash is macular>papular>vesicular>pustular>crusting over

ability to dampen, avoid immune response

variola minor

a form of smallpox; not as severe, less rash, less illness

variola major

a form of smallpox; severe, highly virulent, shock, DIC, sepsis

2 weeks of high fever, malaise, back/ abdominal pain rash with "BB pellet-like" fluid in lesions

chickenpox/ shingles

human herpes virus 3 (HHV-3 aka varicella zoster virus, VZV)

fever, itchy rash vesicles with clear fluid which are contagious until they scab over and fall off

do not give aspirin or else Reye's Syndrome will occur

incubation 10-20 days, lasts 4-7 days

0.1% of chickenpox cases are followed by encephalopathy

transmission: humans are the only natural hosts for HHV-3, if you're exposed, you'' most likely get it; droplet contact, inhalation of aerosolized lesion fluid

ability to fuse cells and become latent in ganglia and re-emerge as shingles (aka: herpes zoster)

MRSA

methicillin-resistant staphylococcus aureus; breaks in the skin by injury/ abrasion

GPC in clusters

catalase (+), coagulase (+)

direct or indirect contact transmission

raised, red, tender, pus, warm to touch, fever

norma flora AND pathogen

common on gym equipment

common norma flora on healthcare workers

impetigo

caused by S. aureus (exfoliative toxin) or S. pyogenes (streptokinase)

superficial bacterial inflammatory skin disease characterized by vesicles, pustules, and crusted-over lesions; honey colored crust, flaky/ peely skin

highly contagious by direct contact and fomites

peak incidence: summer and fall

prevention (good hygiene)

cellulitis

Inflammation of cellular or connective tissue

caused by S. aureus or S. pyogenes (or any bacteria)

fast-spreading infection in the dermis and subcutaneous tissues

common in the immunocompromised

if caused by S. aureus = methicillin resistant (MRSA)

Staphylococcal scalded skin syndrome (SSSS)

S. aureus

dermolytic infection

newborns/ babies

bullous lesions: often appear first around the umbilical cord (in neonates) or in the diaper or axilla area

transmission: when caregivers carry the bacterium from one baby to another

30% of adults are asymptomatic carriers

cutaneous anthrax

B. anthracis GPR endospores, enter skin through cuts/ abrasions

forms eschar (painless and black)

least dangerou anthrax infections

20% fatality rate

class A bioterrorism agent

transmission: direct contact with endospores

fungal infections

transmission: fomites, soil, human contact, animals

mainly caused by 1/3 dermatophytes:

trichophyton, microsporum, epidermophyton

superficial mycoses

fungal infection; malassezia species

cosmetic

dandruff/ skin discoloration

conjunctivitis

pink eye; clear watery exudate "glued shut"

neonates N. gonorrhea or C. trachnomatis

Staph. epidermis, Strep. pyogenes, Strep. pneumoniae, Haemophilus. influenza

prevention: good hygiene

keratitis

more serious eye condition than conjunctivitis; damage to deeper eye tissues, post trauma

80% cases are bacterial

viral (herpes simplex virus HSV1 or 2), protozoan

GI tract defenses

saliva, mucus in the intestinal tract (IgA)

peristalsis

stomach acid

GALT

tonsils

Peyer's patches

Appendix

normal biota of the GI tract

Acintomyces, Lactobacillus, Neisseria, Prevotella, Streptococcus, Treponema, Veillonella, Candida Albicans

oral cavity defenses

Saliva, sIgA, lyzozyme, tonsils, adenoids

accessory organs

salivary glands, gallbladder, liver, pancreas

free of a natural microbiome but can be exposed to microbes when normal barriers in the gut are disrupted by a condition called dysbiosis

dysbiosis

an unhealthy mix of the gut microbiome

normal flora of the gut

Clostridium species, Bacteroides species, Enterobacteriaceae, Escherichia, Lactobacillus

acute diarrhea

3 or more loose stools in a 24 hour period;

treatment: electrolyte therapy

prevention: hand hygiene, follow food safety guidelines, avoid untreated water, cook chicken to int. temp. of 165, follow food safety guidelines

common culprits: salmonella, norovirus, campylobacter, E. coli STEC strains, staphylococcus aureus, clostridium perfringens

salmonella typhi

causes typhoid fever

not common in developed countries

contracted from human feces F/O

resistant to bile

high ID, need 100,000 bacterial cells to get sick

10% human consumption rate

salmonella thypimurium and enteritidis

zoonotic

normal biota of reptiles, chickens, cattle, rodents

resistent to bile

salmonellosis

can be relatively severe with an elevated body temp and septicemia as more prominent features than GI tract disturbance but can also be fairly mild with gastroenteritis, vomiting, diarrhea, and mucosal irritation. blood can appear in the stool.

symptoms spontaneously subside after 2-5 days.

death infrequent unless debilitated

needs electrolyte replacement and ciprofloxacin in severe cases

shigella

GNR, NLF

F/O for infected person, direct contact

low ID

dysentery, fever, intense abdominal pain, vomiting

resembles E. coli

virulence factors:

has enterotoxin that damages the GI tracts (mucosa and villi)

shiga toxin: responsible for more damage to the intestines, systemic effects, neurological damage

invades large intestine villi

enters intestinal mucosa by peyer's patches

can establish chronic carrier that can last several months

transmission: spread epidemically in day care centers, prisons, mental institutions, nursing homes, and military camps

prevention: good hygiene and avoiding contact with infected persons

Shiga toxin-producing E. coli (STEC)

aka: e. coli 0157:H7

acquired shiga toxin from bacteriophage that previously infected S. dystenteriae

bloody diarrhea, fever

transmission: contaminated food. is normal biota in cattle

severe complication: hemolytic uremic syndrome (HUS), kidney failure, blindness, seizure, stroke

hemolytic uremic syndrome (HUS)

Serious condition characterized by red blood cell breakdown and kidney failure; severe hemolytic anemia that can cause kidney damage and failure, neurological symptoms such as blindness, seizure, and stroke, and long-term debilitation

other e. coli that cause diarrhea

enterotoxigenic E. coli

enteroinvasive E. coli

enteropathogenic E. coli

enteroaggresive E. coli

difusely adherent E. coli

campylobacter jejuni

seagull shaped GN bacteria

lives in intestines of poultry, cattle, pigs, sheep, dogs, cats

ingestion of undercooked chicken, contaminated water, feces of pets

watery stool, fever, vomiting, headache, abdominal pain

complication (not permanent): Guillain-Barre syndrime (GBS)

Guillain-Barre Syndrome (GBS)

temporary paralysis caused by an autoimmune attack on peripheral myelin, causing weakness and usually ascending paralysis of the limbs, face and diaphragm

leading cause of acute paralysis in the US

40% of GBS cases are preceded by infection with campylobacter

clostridium difficile

GP endospore-forming rode round in the normal biota of the intestine

antibiotic associated colitis (pseudomembranous colitis)

healthcare associated infection

transmitted from patient to patient

enterotoxin A and B

abdominal pain, leukocytosis, watery diarrhea, vomiting, rapid heart rate, perforation of cecum-death

66% healthcare-associated, 24% did not occur until patient had gone home

vibrio cholerae (cholera)

darting GNR resemble a comma

water/ saline rich areas (Seaports) spread through infected water and food

spread from person to person (F/O) in underdeveloped countries

"rice water" stool

dehydration, blood volume loss

muscle cramps, severe thirst, sunken eyes

electrolyte loss-tachycardia

70% morality rate in untreated children

enterotoxin: cholera toxin: causes intestinal cells to shed large amounts of electrolytes into intestine; 1 liter of water per hour - 50% of patient body weight (severe)

virulence factors:

100,000,000 ID

adhere to junction of duodenum and jejenum, penetrate mucosa barrier w flagella, adhere to microvilli, epithelial cells and multiply

prevention:

proper sewage treatment and water purification

vaccines for travelers (not in US)

rotavirus

primary viral cause of death from diarrhea

F/O route contaminated by food/ water/ fomites

mild and self-limiting diarrhea

watery diarrhea, fever, vomiting, dehydration shock = intestinal mucosa damage

babies without maternal antibodies most affected

50% of all diarrhea cases

norovirus

second more common cause of hospitalization from food-borne illnesses

F/O route via contaminated food/ water

profuse watery diarrhea 3-5 days

mild self-limiting

cruise ship industry affected

3-5 days watery diarrhea, vomiting in early phases, mild fever, make sure to rehydrate

Staphylococcus aureus

food poisoning

on skin of food handler-left unrefrigerated

heat sable can grown in salty/ sugary foods

cramping, nausea, vomiting, diarrhea 24hrs

violent symptoms, short incubation period

bacillus cereus

food poisoning

exotoxin: rice/ pasta = emesis

exotoxin: meats/ veggies = diarrhea

symptoms last 24hrs

common resident on veggies and anything in contact with soil

clostridium perfringens

food poisoning

intestinal protozoan of apicomplexan type that infects a variety of mammals, birds, and reptiles

undercooked beans and meat

avoid by reheating food (heat labile exotoxin)

abdominal pain, nausea, diarrhea 24hrs

urinary tract

has the job of removing substances from the blood, regulating certain body processes, and forming urine and transporting it out of the body

remove metabolic waste from the blood acting as a sophisticated filtration system for the blood

kidneys, ureters, bladder, and the urethra

defense symptoms: flushing action of urine, urine sheds epithelial cells from the lining of the urinary tract

genital system

has reproduction as its major function

aka: the reproduction system

normal biota of the genitourinary tract

lower urethra: has a well-established microbiota

upper urinary tract: has a few types of biota but lower abundance

genirourinary tract defenses

voiding, lyzozyme and lactoferrin, secretory IgA, estrogen

male genitourinary biota

psuedomonas

staphylococcus

anaerobic GN bacteria = uncircumsized

female genitourinary bacteria

lactobacillus, candida albicans (low numbers), gardnerella vaginalis (low numbers)

leptospirosis

a spirochete-caused disease transmitted by contact of broken skin or mucous membranes with contaminated animal urine

vehicle: contaminated soil or water

prevention: avoiding contaminated vehicles

treatment: doxycycline, penicillin G, or ceftriaxone

urinary tract infection (UTI)

result from invasion of the urinary system by bacteria or other microorganisms

cystitis, pyelonephritis, urethritis

symptoms: dysuria, frequent urges to urinate, cloudy urine, back pain, fever

common agents:

95% from normal biota from the GI tract

80% E. coli

Klebsiella pneumoniae

Proteus mirabilis

community-acquired UTIs

transmitted not from person to person, but organ to organ (ex: GI tract to urinary tract) much more common in women than men bc of the short perinatal disease

cystitis

bladder infections

pyelonephritis

kidney infection

urethritis

if the infection is limited to the urethra

vaginitis

inflammation if the vagina: candida albicans overgrowth

broad spectrum antibodies

diabetes

pregnancy

HIV

white curdlike discharge

vaginosis

bacterial in origin with less inflammation: Garnerella vaginalis overgrowth (fish odor) semen

saliva

discharge with fishy smell

group B streptococcus-neonatal disease

no issues for non-pregnant females

associated with preterm delivery

small % blood stream infection, meningitis, or pneumonia

transmission: vertical (passing of an infection or disease from a mother to her child during pregnancy, childbirth, or breastfeeding. This can occur through the placenta, vaginal fluids, or breast milk)

treatment: treat mother with penicillin/ ampicillin

watch for clindamycin-resistant strains as they are a concerning treat category on CDC antibiotic resistant report

prostatitis

inflammation of the prostate gland-caused by GI bacteria

can be acute or chronic

virtually always caused by a bacterial infection

symptoms:

painful urination, frequent urge to urinate, painful ejaculation, difficulty emptying bladder

treatment:

ciprofloaxcin or levofloxacin (antibiotics, muscle relaxers, alpha blockers)

50% men experience in lifetime

STIs that cause discharge

gonorrhea, chlamydia

gonorrhea

caused by Neisseria gonorrhoeae

GN diplococci, kidney/ coffee bean shaped bacteria

pyogenic (pus-forming)

catalase (+)

oxidase (+)

symptoms:

yellow discharge, blood discharge, painful urination, PID, infertility

10% males asymptomatic

50% females asymptomatic

virulence factors:

fimbriae anchor to mucosal epithelial cells

fimbriae can rearrange

IgA protease: can cleavage IgA molecules stationed for protection on mucosal suurfaces

salpingitis

transmission: direct contact (STI), vertical

effects on fetus: eye infections, blindness

salpingitis

inflammation of the fallopian tubes or it may include other parts of the upper reproductive tract (pelvic inflammatory disease (PID)

Chlamydia trachomatis

most common reportable infectious disease in the united states

virulence factors:

grows intracellularly, triggers intense cytokines, greater risk of PID in females

symptoms:

discharge, painful urination

75% infected are asymptomatic

transmission: direction contact (STI), vertical

effects on fetus: eye infections, pneumonia

STIs that cause ulcers

syphilus, congenital syphilus, chancroid, genital herpes

Syphilis

Treponema pallidum

GN spirochete (mainly viewed with dark-field microscopy

virulence:

lipoproteins

hooked up to epithelial cells

penetrates nearby capillaries to spread

primary: painless, hard chancre; 3-6 weeks

secondary: rash, hairloss, bone/ joint pain; 3-6 months

tertiary (non-transmissible): gummas and Argyll-Robertson pupil; 20 years or longer

congenital syphilis

" snuffles" excess profuse nasal discharge

notched barrel teeth in late ______

"hutchinson's teeth"

chancroid

Haemophilus ducryei

painful soft chancre

more common in uncircumcised males

direct contact

rule out other ulcer diseases

avoid contact

genital herpes

HSV 1 and HSV2

80% US pop positive for HSV 1

40% US pop positive for HSV 2

painful tender vesicle with clear fluid

mouth, genitals, breasts, buttocks, thighs, groin

has a strong tendency to become latent

STIs that cause warts

HPV

Human Papillomavirus (HPV)

warts on genitalia, buttocks, groin, thigh, pelvic area

oncovirus-cervial

aslo associated with throat factor

CDC-"nearly all active adults will get HPV at sometime in their lives"

HPV vaccine provides 97% protection against cervical caner and warts

condyloma acuminata: extensivley branching, cauli-flower like masses

has oncogenes as virulence factor

condoms

how to prevent STIs

sexually transmitted, vector borne, fecal-oral route, water/ soil

how are parasites spread?

diagnoses for parasites

O&P test

CBC Blood Smears-high eosinophil count

O&P test

Test for ova and parasites in the stool

CBC Blood Smear

test for high eosinophil count

protozoa

large group of creatures, single-celled, have startling properties when it comes to movement, feeding, and behavior

form and function:

single cells, contain all major eukaryotic organelles

pseudopods: false feet; how they move through fluids, flagella, or cilia

lack cell wall, so theyre flexible

trophozoites

what protozoa are called when theyre in the motile feeding stage

requires ample food and moisture. to remain active

cyst

dormant resting stage when environment become unfavorable for growth and feeding; rounds into sphere, and ectoplasm secretes a thick cuticle around the cell membrane; resistant ti heat, drying, and chemicals and can survive adverse periods, breaks when. theres moisture and nutrients

protozoa life cycle

single-celled organisms

free-living

parasitic

prophozomites

cyst

5 protozoal parasitic infections

trichomonas vaginalis

leishmania species

giardia lamblia

entamoeba histolytica

plasmodium

trichomonas vaginalis

does not survive long outside host body

trichomoniasis (STI):

most common non-viral sexually transmitted disease males

mostly carriers females

mostly symptomatic

causes itchy burning genitals, green white frothy discharge

no cyst form

chronic infection may lead to infertility

Leishmania species

bite with sandfly infected with Leishmania parasite causes leishmaniasis

cutaneous (pictured) = L. tropica

Mucocutaneous = L. brasiliensis

System fatality 100% untreated

Giardia lamblia

Giardiasis

intestines of beavers, cattle, cayote, cats, human carriers (beaver fever)

contaminated food/ water, fomites

greasy foul-smelling diarrhea, flatulence, abd. pain

entamoeba histolytica

amebiasis

food/ water contaminated with feces

1/10th pop asymptomatic carriers loose stool, cramping, stomach pain

hemorrhage, perforation, appendicitis, extra-intestinal infection (amoebic hapatitis)

Plasmodium

transmitted by female anopheles mosquitos

most infections close to the equator

symptoms: malaise, fatigue, body aches, chills, fever, sweating in 48-to-72 hour intervals

over 200 species:

P. malariae

P. vivax

P. knowlesi

P. ovale

P. falciparum (most deadly)

complications from plasmodium infections:

hemolytic anemia

Enlargement/ rupture of organs (spleen, liver, kidneys)

Cerebral Malaria

diagnosis and treatment:

CBC Blood smear-thin and thick smears

Medication quinine, chloroquine, Artemisinin

helminths

Nematodes (roundworms)

Cestodes (tapeworms)

Trematodes (flukes)

helminths life cycle

Sexual reproduction

Hermaphrodite (tapeworms, flukes)

Fertilized egg, larvae, adult worm

intermediate host: host in which larval development occurs

definitive host: final host where adulthood and mating occurs

parasitic nematodes

enterobius vermicularis, trichuris trichuria

Enterobius vermicularis

"pin worms"

infects large intestine. female enterobius vermicularis mature in 1 month and mates deposits eggs into anus

causes anal itchiness, restlessness, loss of appetite, weight loss

trichuris trichuria

"whip worm"

contaminated first or feces with eggs

hemorrhage of bowls, dysentery, loss of muscle tone, rectal prolapse

parasitic cestodes

Diphyllobothrium latum, Taenia solium