Mizzou Microbiology 3200- exam 4

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What type of staining do we use for myobacteria?

Acid-fast stain

what disease does M. leprae cause?

Hansen's disease, leprosy

what disease does MAC and M. avium complex cause?

Disseminated respiratory infections & HIV+

what are the 5 mycobacteria cause TB?

M. tuberculosis, M. africanum, M. bovis, M. microti, M. caprae

What disease does M. ulcerans cause?

Buruli ulcer

what disease does M. Marinum cause?

Fishtank granuloma

the mycomembrane is composed of what?

mycolic acids which form a waxy, hydrophobic coat

what are the 3 main symptoms associated with TB?

fever, rapid weight loss, frequent night sweats

when the bacteria goes into latent infection, it is contained in what?

primary granuloma

During a TB skin test, what causes local swelling and inflammation

Stimulation of memory T cells

does TB skin test determine between latent and active infection?

No it cannot, it can only detect exposure

what two M. tb proteins are used in the Quantiferon-TB gold test?

ESAT-6 and CFP-10

what happens during the quantiferon-TB gold test if the patient is infected?

their white blood cells will release interferon-gamme in response to contact with TB antigens

what quantiferon-TB gold test determine between latent and active infection?

No

what testing is required to actually determine between latent and active infection?

CXR, sputum culture, acid-fast staining,

Growth of lowenstein-jensen agar (Brown-granular appearance)

What treatment is used for TB?

combination therapy: Isoniazid, rifampicin, pyrazinamide, and ethambutol for 2 months, then isoniazid and rifampicin alone for a further 4 months. //along with direct observed treatment, short-course

what is direct observed treatment, short-course

observation by a healthcare worker to ensure patient completes treatment

what does the drug rifampicin inhibit?

RNA synthesis

what happens when a patient has HIV and TB?

treatment is complicated due to drug interactions with TB drugs and HIV drugs.

what parts of the body does leprosy affect?

cooler parts (skin, upper respiratory and testes)

leprosy can lead to what?

deformities and blindness

what is damaged by leprosy disease?

nerve cells and neurons

M. leprae replicates within what cells?

macrophage/dendritic cells and schwann cells

what are the two forms of leprosy disease?

tuberculoid leprosy & lepromatous leprosy

what characteristics are associated with tuberculoid leprosy?

Strong cell mediated immunity, macrophage killing, few bacilli in skin smears

what characteristics are associated with lepromatous leprosy?

Weak cell mediated immunity, strong humoral immunity, many bacilli in skin smears

what is the clinical presentation of leprosy?

Skin lesions: plaques and macules

Enlarged and tender nerves

Painless ulcers on feet

Loss of eyebrows/eyelashes (nerves to hair follicles are damaged and cannot communicate)

Muscle weakness, sensory deficits, loss of sweating

what is the transmission route of buruli ulcer?

unknown

is buruli ulcer fatal?

no

buruli ulcer disease is mediated by what toxin?

mycolactone

what forms do fungi exist as?

yeasts (budding single cells ) and molds (filamentous or hyphal form)

what fungi is a budding yeast?

cryptococcus neoformans

what fungi is a dimorphic?

candida albicans, candida auris, histoplasma capsulatum

cryptococcal disease is a hallmark infection of what diease?

HIV

does cryptococcal disease have person-person tranmission?

no

what disease is caused by cryptococcus neoformans?

cryptococcal disease

is asymptomatic infection common in cryptoccocal disease?

yes

cryptoccocal disease is a common cause of menigitis where?

africa

what fungi only grows virulent strains at 37 degrees C?

cryptococcus neoformans

lumbar puncture is essential for diagnosis of what pathogen?

cryptococcus neoformans

what are the high risk activities associated with Histoplasmosis

construction, exploring caves, home renovation, tilling soil

Thrush is caused by an excess of what fungi found in the GI tract?

Candida albicans

what fungi is Histoplasmosis caused by?

Histoplasma capsulatum

the calcified nodules on the lungs associated with Histoplasmosis is often confused with what other disease?

Millary TB

severity of illness is directly related to what when it comes to protozoa?

infectious dose and the number of repeated exsposures

Amebiasis is caused by what pathogen?

Entamoeba histolytica

what is the clinical presentation of amebiasis?

Water diarrhea --> blood and mucoid

Coloscopy: ulcers

Pathology: flask shaped ulcerations

what complications are associated with amebiasis

Peritonitis,

Appendicitis and cecitis,

Necrotizing colitis and toxic megacolon

what occurs with amebic liver abscess?

amoebas resist killing by complement proteins enter the hepatic portal vein and colonize the livers

what are the symptoms associated with amebic liver abscess

flank pain, fever (blood tests have aspartate and alanine aminotransferase levels are elevated which suggests liver damage)

what is the reservoir for giardia lamblia

humans or beavers

what is the clinical presentation associated with Giardiasis?

Diarrhea

Greasy stools that float

Gas bloating

Nausea

what is the post infectious problems associated with giardiasis?

irritable bowel syndrome

what is the diagnosis for Giardiasis: Giardia Iamblia

Stool for ova & parasites- but unreliable

Fecal antigen detection

Balantidium coli is mainly associated with what animal

pigs

what groups are at risk for infection of balantidium coli

occupational infection of farm workers and meat handlers

what is required for diagnosis of balantidium coli

trophozoites in stool

what are the intestinal coccidia and their sizes?

cryptosporidium hominis (tiny), cyclospora cayetanensis (mid-size), cystoisospora belli (large and ovoid)

what is the clinical presentation of crypto

Causes voluminous, watery diarrhea, without RBCS and WBCS

Causes self-limited disease in immunocompetent hosts

Causes chronic disease and biliary tract disease in immunocompromised hosts (AIDS)

what is the diagnosis associated with crypto

ova and parasites (acid fast stain of concentrated stool)

malaria is caused by which species of plasmodium

P. falciparum (most virulent)

what are the total 5 species of plasmodium?

P. falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi

what is the clinical presentation of malaria

Non-specific symptoms Headaches Malaise Cough Fever

Classic paroxysms : high fever, shaking and chills

the classis paroxysms associated with malaria repeat every 48 hours due to what?

the parasite-life cycle of P. falciparum

what is the severe disease associated with malaria

Jaundice --> liver failure

Shock --> potential multiple organ dysfunction/failure

Respiratory failure

Abnormal behavior, seizures, coma, neurologic problems --> cerebral malaria (brain is starved of oxygen)

infection of plasmodium falciparum is severe due to what?

Infects RBCS of all ages, shortest incubation period, most rapid erythrocytic cycle (24-48)

cerebral malaria occurs because of what?

RBCS stick together due to basophilic stippling and it causes blockages in capillaries

what is the reservoir associated with malaria infection?

humans

what is the definitive host associated with malaria and why?

anophele mosquitos// plasmodium reproduces sexually only in the mosquito

why are humans considered the intermediate host when it comes to malaria?

we infect the mosquitos

how we diagnose malaria

micrscopy (gold standard, uses thick and thin blood smears stained with glemsa stain)

what is the difference between thick and thin smears associated with diagnosing malaria?

thick smears --> presence of parasites

thin smears--> species-level identification

what can occur with the blood smears in endemic areas of malaria?

patients may have positive smear and not have clinical malaria

which species of babesia causes the most human infections?

B. microti

babesia species look like what other species?

plasmodium spp.

what is the reservoir associated with Babesia spp.

Deer, cattle and rodents

what is the vector associated with babesia spp.

ixodes scapularis (Deer ticks)

what groups are at risk of babesiosis

lack of spleen, old age, immunocompromised

what are the symptoms associated with babesiosis?

high fever, shaking, chills, malaise, headache, fatigue, dark colored urine (due to hemolytic anemia)

The disease associated with leishmania species is transmitted by what animal?

sand fly

what are the reservoirs associated with leishmania

humans (old world only), rodents, canines, equines, monkeys, sloths

what disease is associated with volcano sign lesions?

cutaneous leishmaniasis

Visceral Leishmaniasis is also known as what?

kala-azar, black fever, and dum dum

visceral Leishmaniasis is caused by what?

leishmania donovani

(T/F) most people infected with visceral Leishmaniasis are asymptomatic

True

what is the pentad of symptoms associated with visceral Leishmaniasis

fever, cachexia, hepatosplenomegaly, pancytopenia, hypergamma-globuliemia

what diseases are caused by Clostridium perfringens

food poisoning and gas gangrene

what diseases are caused by Clostridium difficile (now clostridicdes)

antibiotic induced diarrhea, pseudo-membranous colitis

what diseases are caused by Clostridium botulinum

food-borne botulism, infant botulism, wound botulism

what disease is caused by clostridium tetani

tetanus (lockjaw)

what are the general features of clostridia?

gram-positive rod, some are motile, spore formers, many species secrete toxins, and obligate anaerobes

symptoms associated with clostridium perfrigens infection usually starts how long after consumption

8-22 hours and usually lasts around 24

what is the important toxin associated with clostridium perfrigens?

alpha toxin

clostridium perfrigens results from what?

temperature abuse of foodenter

clostridium perfrigens bacteria produce what?

enterotoxins

why is gas gangrene usually characterized by a foul-smell?

there are gaseous metabolic products produced that smell foul from the

what causes the swelling and tissue death associated with gas gangrene?

a-toxin and PFO

how do we diagnosis gas gangrene associated with C. perfrigens?

lesions, presence of large G+ bacilli, and nagler toxin

what can result within one week of a gas gangrene infection

shock, kidney failure, and death

the nagler test determines the presence of what?

alpha toxin