Diseases – Microbiology – Flashcards

produce urine and filter blood

-nephrons are its functional unit, they are located in the renal pyramids of the kidneys

-appox. 1.25 million nephrons per organ

-contains glomerular (leaky capillaries)

what takes urine out of the body

- much longer in males, 3x longer than in females

–      Urinary and reproductive systems are distinct, no shared organs

•          Normally urine and urinary tract above bladder are sterile

–        Urethra contains normal resident flora

steptococcus, staphylococcus, cornyebacterium, lactobacillus

- normal flora varies in female repoductive tract dependent upon hormones (lactobacillus)

-affect both men and women

-urinary tract infections

-Leptospirosis

•          8 million cases annually in US

–        600,000 nosocomial 

–        Primary ascending infection, pathogens enter in through the urethra and continue up to other organs

–        May include any or all of the organs

–        Usually intestinal flora

•          E. coli – most common, about 70% of urinary tract infections

•          Proteus and Klebsiella

•          Pseudomonas

        Typically nosocomial 

–        Dysuria; cloudy urine with foul odor; may have pale red color from blood being lost in the urine, pain when urinating

–        Tenderness of pelvic area,   May have slight fever 

–        Pathogens typically ascend urethra and attach to receptors on bladder lining

–        May form biofilm

–        when urinary tract infection makes it to the kidneys, which makes it likely for the infection to make it into the bloodstream 

•          Sudden elevation of temperature, chills, vomiting and back pain, bacteremia

–        Typically results from auto-inoculation

–        30% of women develop at least one UTI

–        Risk factors include: short urethra; sex (males are less susceptible to UTIs); use of diaphragm; pregnancy, catheterization; women more predisposed for getting urinary tract infections

–        Adequate fluid intake 

–        Cranberry juice may help prevent attachment

–        Void urine immediately after sex

–        Proper personal hygiene

–        Sulfonamides or cephalosporins, sulfa drugs

-zoonotic disease

•          Hard to stain, hard to grow, have a hook on the end that makes them more recognizable

  Leptospira interrogans

•          Gram -, Spirochete

•          Double axial filaments making them very efficient at swimming and crawling

•          Over 200 antigenic types

•          Begins in kidneys because it comes from the bloodstream

–        Abrupt onset of headache, spiking fever, chills and severe myalgia

–        Eye redness which is directly related to the vessels that feed the eye become very dilated causing major redness.  

- ½ of patients develop nausea, vomiting and diarrhea

-          Requires direct contact with urine or urine contaminated waters or soil

-          Bacteria enter body through mucous membranes and breaks in skin, eventually colonizes in the kidneys

-          Organism multiplies and travels to kidneys in blood stream

–        Rarely fatal, if fatal its due to renal failure or meningitis, can cause meningitis if it contacts the meninges

–        Worldwide distribution, all types of animals

–        Infects, many wild and domestic animals

•          Asymptomatic carriers

–        Organism is excreted in urine

•          Survives in water for weeks, even extremely cold water

–        Farmers, ranchers, butchers, vets at high risk

–        Avoid water contaminated with animal urine

–        Maintain sanitary conditions for animals, try to prevent run off into water ways

–        Vaccine available for livestock and pets

–        Rodent control

–        Oral doxycycline, chloramphenicol, erythromycin

–        IV penicillin in severe cases, usually if someone is having rare complications

•          May affect males (due to wounds in men) and females

–        Bacterial Vaginosis

–        Vaginal Candidiasis

•          Staphylococcal Toxic Shock Syndrome

•          Causative agent: Staphylococcus aureus

•          Virulent strains produce Toxic Shock Syndrome Toxin (TSST1 or TSST2), type 1 produces the majority of toxic shock syndrome cases

–        binds cells of immune system and triggers excess immune related chemicals be released, many people carry this in their mucus membranes and on the skin 

–        Sudden onset fever, chills, vomiting, diarrhea, extremely low blood pressure, mental confusion due to low blood pressure and a severe red rash

–        50% mortality if untreated due to septic shock

•          Most cases involve menstruating women

–        25% of cases involved wound infection

–        New mothers and surgical patients also at risk

–        Avoid highly absorbent tampons, diaphragms, contraceptive sponges or use them for shorter periods of time, also change packing of a wound regularly

–        Remove foreign matter or drain infected wound immediately

–        IV fluids to support blood pressure

–        Vancomycin (gets rid of bacteria) and anti-TSST immunoglobulin (antitoxin)

–        May be caused by multiple anaerobic bacteria

–        Gardnerella vaginalis: not part of normal flora but is common in environment, cannot grow in pH lower than 5

•          Change in vaginal flora

–        pH increases and allows overgrowth of pathogen

•          Thin, grayish-white vaginal discharge due to anaerobic metabolism

•          Can be slightly bubbly

•          Pungent ‘fishy’ odor

•          Some itching and irritation

•          50% asymptomatic

•          No proven prevention

•          Associated with multiple sexual partners, vaginal douching, anti-microbial therapy, however, all of which will alter pH; do not want vaginal pH to change

•          Metronidazole: antiprotozoal drug that works on anaerobic bacterial infections, cannot be taken during pregnancy of breast feeding mothers so their only choice is vinegar douche

•          Vinegar douche: this will drop the pH back where it should be

•          Reestablishment of lactobacilli

•          Candida albicans

•          Normal flora for up to 80% of women

•          Opportunistic pathogen

•          Dimorphic: two different forms of growth

•          Diagnosed by budding yeasts

•          White mucoid colonies on vaginal mucus membranes and labia 

•          Severe itching and burning which will increase with urination

•          White curd-like discharge like cottage cheese

•          Can result in serious candidasis in someone who is immunosuppressed

•          Can be spread person to person—mother to child which is rare within fungi

•          Mother to newborn

•          Rarely sexually transmitted

•          Antibacterial medications increases risk

•          Other risk factors include birth control, hormone therapy, AIDS, diabetes, invasive hospital procedures and cancers

•          100% of AIDS patients get candidasis due to low immune system

•          Changes in vaginal flora and pH

•          Intra-vaginal treatment with nystatin and clotrimazole

•          Cream azoles may weaken latex condoms by dissolving the latex

•          Oral fluconazole especially used in immunosuppressed individuals

•          Epidemic over last 50 years

–        330 million annually worldwide

•          Often asymptomatic in women

–        Increased risk of pelvic inflammatory disease, ectopic pregnancy, miscarriage, birth defects, sterility and cervical cancer, damage to important female parts

–        Proven effective

•          Sexual abstinence & mutual monogamy

–        Somewhat effective

•          proper, consistent condom use

•          ~20% failure rate, do not prevent the spread of certain viruses

•          bacterial diseases

–        Increased fluid discharge for males and females

•          Gonorrhea (clap)

•          Chlamydia

•          co-infections ~45% of cases, if you have one you have the other

–        Lesions on genitals of males and females

•          Syphilis

–        Neisseria gonorrhoeae

•          Gram-negative; diplococci

•          Fimbriae and capsule makes it easy for it to attach to reproductive tract, destroys your antibodies

•          Low infecting dose, just a few cells is all it takes

•          White blood cells full of Neisseria that are reproducing quickly: clinical sign of gonorrhea 

      In men: Most men are symptomatic,    Pain on urination, discharge from penis

    In women:  Women more likely to be asymptomatic (50-80%),    Painful urination, mild discharge,  May be overlooked as UTI

    ~25% develop PID (Pelvic Inflammatory Disease)

–        Less common manifestations:   Heart damage, arthritis, meningitis, UTI, pharyngitis 

•          antigens change so they are not attacked or recognized by immune system (antibodies)

–        protects from antibodies

•          Opa proteins on fimbriae bind to T-cells

–        Prevents activation of immune response

•          IgA proteases

•          Gonococci survive and multiply in WBCs

•          when gonorrhea is passed to child during childbirth

–        Gonococcal conjunctivitis of the newborn

–        Acquired from infected birth canal

–        Prevented with silver nitrate or erythromycin in eyes

–        Humans only host

–        Risk increases with number of sexual partners

•          More common in blacks(4X) and males (slightly)

•          Most cases involve adolescents with multiple partners

•          Birth control pills: by changing hormone levels it makes mucus lining of reproductive tract more likely to contract infections

•          Asymptomatic Carriers

•          Lack of immunity: gonorrhea changes so much your body will never figure out how to fight it

–        No vaccine available

•          Antigenic variation interferes with ability to make effective vaccine

–        Doxycycline for co-infection, best choice because it treats both

–        Broad spectrum cephalosporins

•          Increasing number of strains resistant to numerous antibiotics

•          Chlamydia trachomatis

•          Non-motile; obligate intracellular pathogen

•          Gram – with no PTG

•          Non-gonococcal urethritis (7 strains)

•          Lymphogranuloma venereum (3 strains)

•          Leading cause of preventable, non-traumatic blindness

       In men: Most (75%) symptomatic, Thin grayish-white discharge from penis, Sometimes epididymitis or orchitis,  May lead to sterility

–        In women:  Most (85%) asymptomatic,  Increased vaginal discharge, painful urination, Risk of PID and sterile,  Increased risk of cervical cancer for adolescents

–        Severe chlamydial STD (LGV strains)

–        Strains tend to be isolated to the tropics

–        Characterized by genital lesion at site of infection

–        Followed by bubo in groin, fever, chills, myalgia and arthritis

•          Trachoma strains multiply in cells of conjunctiva

–        Kills cells and stimulates production of purulent discharge which scars conjunctiva

–        Eyelids turn inward and eyelashes scar cornea

–        Cornea fills with blood vessels and blindness results 

–        Most common reportable STD in US

–        500 million cases of trachoma worldwide

•          Newborns infected at birth

•          Direct, indirect and vector transmission also possible

–        Azithromycin; tetracycline or erythromycin

–        Doxycycline for co-infection with gonorrhea 

–        Erythromycin cream in infant eyes for 10-14 days for trachoma

–        Treponema pallidum

•          Narrow Gram -, spirochete

•          Axial filaments

•          Can’t be cultivated in artificial media

–        Occurs in numerous forms, Often confused with other diseases,    “great imitator”

       Manifestation occurs in three stages

•          Primary stage

•          Secondary stage

•          Tertiary stage

•          Characterized by hard, painless, red ulcer

–        Chancre

–        Appears at the site of infection

•          Local lymph nodes become enlarged

•          Spontaneous healing of chancre

•          Runny nose, watery eyes, sore throat, oral lesions, generalized aches and pains

•          Non-itchy rash

–        Usually on palms and soles of feet

•          Spontaneous healing

•          Characteristic lesions called gummas

•          Infection attacks other organs

•          Numerous nervous system disorders

•          Blindness; metal illness; stroke

•          Organism crosses placenta

•          Nearly 40% result in miscarriage or stillbirth

•          Begins as an early profuse nasal discharge

•          Most children develop deformities

–        Hutchinson’s teeth, saddle nose, sabre shins

•          Organism penetrates mucous membrane and broken skin

–        Low infecting dose: Less than 100 organisms

–        Organism multiplies in localized area

•          Chancre caused by immune response

•          Spreads to lymph nodes and bloodstream

–        Human only host

–        Transmitted via direct contact, blood transfusion, mother to fetus 

–        12 million annual cases worldwide

–        Maintain low incidence in US

–        VDRL test used for diagnosis

–        Primary, secondary and congenital stages effectively treated with penicillin

–        No proven alternative for those with penicillin allergy

–        Antibiotics not effective for tertiary

–        Herpes (viral ulcerative STD)

–        Genital Warts

–        AIDS

–        Protozoal STD

–        Trichomoniasis

–        herpes-simplex virus type 1 & 2

–        Enveloped DNA virus

–        Latent virus

–        Genital itching and burning, fever, myalgia and malaise

–        Numerous fluid filled blisters on genitals

•          Burst and form lesions

–        Lesions heal spontaneously

•          Most patients will have recurrence

•          Enveloped virus fuses with host cell membrane

–        Genome enters cell and begins replication

–        Viruses are released by budding and cell lysis

•          Blisters form when epithelial cells are killed

–        Rupture to produce painful ulcerations

–        Releases millions of viral particles

–        1 in 3 newborns affected if mother infected at birth

–        Debilitating and potentially lethal

–        Requires cesarean delivery

–        4 billion infected worldwide

–        No animal reservoir

–        Non-sexual transmission may occur

–        Transmission most likely occurs during first days illness

•          Transmission can happen in absence of symptoms

–        There is no cure for genital herpes

•          Once infected there is lifelong risk of transmission

–        Acyclovir and derivatives reduce severity

–        Condoms may not be effective in prevention!!!

•          Human papillomaviruses

–        30 different HPV strains cause warts

–        Most common STD in US

•          Warts on genitals, vagina and cervix, Slight pain or itching may occur,  May form condylomata acuminata, Warts typically not dangerous 

–        HPV linked to 99% of cervical cancers, May also cause anal, penile, vaginal and oral cancers

•          HPV infects approximately 20 million people in the United States, ~ 6.2 million new cases each year,   Pap smears don’t detect HPV only abnormal cells

–        DNA test is available that detects all 13 strains linked to cervical cancer

Removal of warts by freezing, laser or acid, Typically reoccur

–        Human Immunodeficiency Virus (HIV)

•          Most US cases causes by HIV-1

•          Most African cases caused by HIV-2

–        Enveloped, RNA retrovirus

–        Fever; head and muscle aches; enlarged lymph nodes; rash

–        Some individuals are asymptomatic for years

•          AIDS is characterized by the presence of several opportunistic or rare infections and a T cell count of lower than 200/µl

–        HIV infects host cells

–        RNA reverse transcribed to DNA

–        DNA integrates as provirus in host chromosome

–        Virus may leave genome and kill host cell

•          Releases additional viruses

–        Immune system becomes impaired

–        HIV is spread mainly through sexual contact, needles or from mother to newborn

–        Global pandemic –        40 million cases

–        ~1/3 have developed AIDS

–        Sexually transmitted, and transferred through any body fluid, can infect a fetus through the placenta

–        No vaccine available: because of so many antigenic strains due to so many changes in its DNA as it multiplies, Interruption of mother to child transmission via chemotherapy

–   Needle exchange programs: you bring dirty needles in and can get clean needles

–        Educational programs targeting at risk populations

–        Treatment of other STDs to lessen risk

–        Designed to block replication and release of virus

•          Generally with cocktail of medication (HAART): Highly active anti retro viral therapy

•          Include reverse transcriptase inhibitors; protease inhibitors; and nucleotide analogs

protazoal

–        Trichomonas vaginalis

–        Flagellated leaf shaped protozoan with undulating membrane

–        Anaerobic bacteria

–        Most women symptomatic: Itching of vulva and inner thighs, Itching and burning of the vagina,  Frothy, odorous yellowish-green vaginal discharge

–        Most men are asymptomatic: penile discharge, pain on urination, tender testes or prostatitis

–        No encysted stage so it can’t survive in environment

–        Reproduces at pH of 5-6: associated with suppression of normal flora

–        Reddening and swelling of vagina attributed to trauma of moving protozoan

–        Frothy discharge most likely due to gas production by organism

–        Humans are the only known host

–        Sexually transmitted or through fomites

–        Worldwide distribution:   170 new cases worldwide annually,  7.5 million in US

–        Most common curable STD in women

–        Transmission usually sexual contact; fomites; newborns infected in birth canal

–        Single dose of metronidazole- pregnant women cannot use this because it passes thorugh breast milk and can affect the fetus

–        Both partners should be treated to prevent re-infection

–        Vinegar douche for pregnant or nursing women

–        Bundles of thin extensions from nerve cells called axons

–        Carry nerve impulses

–        Nucleus in the cell body

–        ganglion

-meninges

-cerebrospinal fluid

-bone casting

-blood-brain barrier

•          protective covering of the brain and spinal cord, deramata (outer most layer), eranamater, piamata (cerous membrane that directly touches brain and spinal cord)

•          None, Viruses can exist in a dormant state in the nervous system

–        penetrate CNS by traveling up nerve bundles

–        Herpes simplex and rabies viruses

–        Bacterial meningitis

–        Tetanus

–        Rabies

–        Viral encephalitis

–     epidemic, fimbriae, capsule, and endotoxin

-pathogen of the nervous system 

 leading cause prior to vaccine, gram negative, high plamorphic (many shapes); pathogen of nervous system

 listeriosis in fetuses, pregnant women, and  immunocompromised individuals, gram positive, oval shaped (coxobacili), can contaminate dairy products, has enzymes that allow it to escape phagocytosis; pathogen of nervous system

 causes most cases of newborn meningitis, some women carry this as the normal flora in their vagina; pathogen of nervous system

–        Acute high fever and severe meningeal inflammation

•          Inflamed cranial meninges – severe headache, vomiting, pain

•          Inflamed spinal meninges – stiff neck, altered muscle control

•          Encephalitis may cause behavioral changes, coma, and death

•          Petechiae may appear on skin, these are subdermal hemorrhages

•          S. agalactiae acquired during birth because it is carried in vaginal flora

•          Listeria transmitted via contaminated food

•          S. pneumoniae, Neisseria & Haemophilus all transmitted via respiratory droplets

•          S. pneumoniae present in throat of 75% of humans without causing harm

•          Meningococcal meningitis is the only form that becomes epidemic

–        Based on symptoms and culturing of bacteria in CSF from spinal tap and then culture the spinal tap

-dependent on pathogen

•          Vaccines available for S. pneumoniae, H. influenzae, and N. meningitidis

•          Individuals at risk for listeriosis should avoid high-risk foods (milk, cheeses, undercooked meat)

•          Mass prophylaxis with ceftriaxone or rifampin helps control epidemics of meningococcal form

•          ceftriaxone or penicillin

–        Tightening of jaw and neck muscles

•          difficulty swallowing and breathing

–        Restlessness and irritability

–        Increased contractions spreading to other muscles  

•          Back spasms

•          Difficulty breathing and death

–        Prolonged contraction of diaphragm

•          Bacteria contained to anaerobic tissue around wound

•          Tetanospasmin toxin moves to CNS and blocks inhibition of motor neurons causing paralysis, toxins that are bound to nerves remain bond and is permanent

•          50-90% mortality rate in untreated cases

–        C. tetani found in dirt and dust and GI tract of humans and other animals

–        Nearly half of infections result from puncture wounds including

•          Body piercing, tattooing, animal bites, IV drugs

•          Frequently fatal but rare in the developed world

–        30 to 60 cases reported in US annually

–        Immunization with toxiod vaccine

•          DTaP

–        Thoroughly clean wound

•          Remove all dead tissue and foreign material

–        Penicillin to kill multiplying bacteria

•          Will not destroy endospores

–        Antitoxin

•          Neutralizes only circulating toxin

•          Causative agent: Rabies virus

•          Lyssavirus family

•          Enveloped ssRNA

•          Spiked bullet shaped virus due to envelope it is in with spikes that help it attach to host cells

–        Virus multiplies in brain forming Negri bodies ( inclusions in the brain)

–        Pain and itching at site of infection

–        Fever, headache, myalgia, sore throat, fatigue

–        Progress rapidly to secondary symptoms

•          Encephalitis, agitation, confusion, hallucinations, seizure, increased sensitivity to light and touch, coma

•          Increased salivation and difficulty swallowing

–        Results in frothing of mouth

•          Hydrophobia occurs in 50% of cases, this is an extreme fear of water

•          About 50% of patients die within 4 days

•          Virus enters through bite of an animal

•          Attaches to skeletal muscle cells triggering endocytosis

•          Pathogen moves across neuromuscular junction into nerve cell and travels to CNS

•          Slow moving so long incubation period

–        1-2 months up to several years 

•          Viruses travel back to the salivary glands and are secreted in saliva

–        Zoonotic: many animal carriers, due to vaccinations dogs are not that common

–        Skunks, raccoons and bats considered chief reservoir

•          75% of human cases linked to bat bites

–        0 to 4 reported cases in US annually

–        Vaccination of domestic animals and Vets

–        Wash wound immediately and thoroughly

•          apply antiseptic

–        Risk lowered if vaccine administered as soon as possible, must be vaccinated multiple times after the bite

–        Interferon may be applied to wound

–        No effective treatment for rabies

•          Only six known survivors of disease

spread by arthropods, most commonly mosquitos

•          Causative agent: Arboviruses

•          mosquitoes

–        Zoonotic diseases: Horses, birds and rodents 

–        West Nile encephalitis, LaCrosse encephalitis, WEE, EEE, VEE, St. Louis encephalitis

–        Named based on where they are found, like VEE: Venaswaline

–        3-7 day incubation period

–        Characterized by mild flu-like symptoms

•          Fever; headache; vomiting

•          One or more nervous system abnormalities

–        Disorientation, localized paralysis, deafness, seizures or coma

•          Only minority infected develop encephalitis

•          Others may develop viral meningitis

•          Most reported human cases in immunosuppressd individuals

–        Elderly and very young

–        Healthy immune system typically fights off virus with only mild flu-like symptoms

–        Viruses multiply at site of bite and in local lymph nodes

•          viremia

–        Virus crosses blood-brain barrier

•          Damages neurons

–        Causes extensive damage to brain tissue in severe cases

–        Progression of disease halted by neutralizing antibody

–        Mortality ranges from 2% to 50% depending of type of infecting agent and host

–        Disease are all zoonoses

•          Maintained naturally in birds and rodents

–        Humans are accidental hosts

–        LaCrosse encephalitis usually causes most reported cases

–        West Nile an emerging disease in US

•          Appeared in New York in 1999

–        Eliminate vector habitat, eliminating mosquitoes

–        Avoiding outdoor activities at night

–        Windows and porches properly screened

–        Use insect repellents and insecticides

–        Vaccine available for horses

–        No proven antiviral therapy