Flashcards About Test on Exam 3 – Microbiology
Unlock all answers in this set
Unlock answers| Vaginitis |
Tricomonas Vaginalis Candida Albicans |
| Vaginosis |
Mobiluncus spp. Gardnerella Vaginitis |
| Environment for Trichomonas Vaginalis? |
| Obligate Anaerobe |
What are the agents that account for 50% of all cases of vaginitis and vaginosis?
What are the environments of these agents? |
Mobiluncus Gardnerella
Both are obligate anaerobes |
| Most common agent of acute, uncomplicated cystitis (79%)? |
| Escheria coli |
| Second most common agent of acute uncomplicated cystitis in women? Characteristic? |
| Staph saprophyticus; coagulase negative |
| What is the primary agent for complicated UTI? |
| Escherichia Coli |
| For which type of UTI is the agent different? What is that agent? |
The type of UTI that is NOT due to E. Coli is catheter-associated UTI.
The agent for catheter associated UTI is candida albicans. |
| Pyelonephritis: most common agent (89%) |
| E. Coli |
| Kidney Stones; what is produced by bacteria? Number one agent? |
| Urease is produced. Corynebacterium |
| Hematogenously Acquired UTI: most common agent? characteristic? |
| Staph aureus (coagulase positive) |
| Syphilis/GUD agent |
| Treponema Pallidum |
| Chancroid/GUD agent |
| Haemophilus ducreyi |
| Gonorrhea (urethitis/cervicitis) agent |
| Neisseria gonorrhoeae |
| Chalmydial urethitis/cervicitis agent |
| Chlamydia trachomatis |
| Lymphogranuloma venereum (LGV)/GUD agent |
| Chlamydia trachomatis |
| Genital Herpes/GUD agent |
| HHV 2 and HHV 1 (to a lesser extent) |
| Cervical Papillomas & condyloma acuminatum (external anogenital warts) agent |
| Papillomavirus |
| Agent of Focal Encephalitis |
| HSV-1 |
| Agent of Diffuse Encephalitis |
arbovirus
|
| Agents of encephalomyelitis |
| Poliovirus and West Nile Virus |
| Class of primary agents for encephalitis? (virus or bacteria) |
| Virus |
| Most common cause of meningitis? |
| Viruses |
| Second Most common cause of meningitis? |
| Bacteria-7 major agents |
| For mass lesions, humans are the _______ hosts of parasites. |
| intermediate |
________ produce cystic lesions and act as a parasite on humans. E.g. T. solium and echinococcosis-hydatid cyst |
| Helminths (flat worms) |
| A _______ is formed in the parenchyma as a result of human immune response to protozoan infection. |
| pseudocyst |
Protozoan Agent of mass lesions? |
| T. Gondii (toxoplasmosis) |
| What is a neurotoxic disease? |
| Pathology due to an exotoxin |
| Name two neurotoxic diseases and the infectious agents of both |
Tetanus: Clostridium Tetani Botulism: Clostridium botulinum |
PNS disease that causes infection of sensory nerves? Give etiologic agent.
|
| Leprosy: mycobacterium leprae |
| PNS disease that involves the demyelination of the PNS. etiologic agent? |
| Guillain-Barre Syndrome; campylobaceter jejuni |
| Does bacteria preferentially cause meningitis or encephalitis? |
| Usually meningitis, but it can cause encephalitis. |
| When deciding what bacteria is the cause of a meningitis, what factor must be taken into account? |
| AGE |
| What kind of meningitis do viruses cause? |
| Aseptic meningitis |
| What are the viral agents for meningitis? |
HHV-6 and HHV-7 Non polio enteroviruses (coxsackie and ECHO viruses) Arbovirus Mumps (unless countries immunize against it) |
| What group of people does HHV-6 and HHV-7 attack in viral meningitis? |
| infants and young children |
| which viral agent of meningitis is more common in children, but more sever in adults? |
| non-polio enteroviruses |
| Which agent of viral meningitis is a risk for in sexually active individuals? |
| HSV-2 |
| which encephalitis is caused by arbovirus? which seasons does this usually occur in? |
| diffuse encephalitis; summer/fall months |
Name two rare causes of focal encephalitis: One is rare due to animal vaccination. The other is rare due to human vaccination |
Rabies virus and Mumps/measles virus |
CURRENT number one etiologic agent for responsible for community-acquired bacterial meningitis?
|
N. Meningitidis!
After mumps/measles, H. influenzae, and conjugated pneumoccocal vaccines have been developed, nesseria is now the biggest agent. |
| If a neonate or adult acquired meningitis during the summer, what is the most probable agent? |
| listeria Monocytogenes |
| If an infant or child acquired meningitis during the winter or spring season, which agent is most likely responsible? |
| H. influenzae |
| If an infant or young adult presented with meningitis in the winter, what is the most likely agent? |
| N. Meningiditis |
| If an infant or an elderly person presented with meningitis during the winter, what is the likely agent? |
| S. Pneumoniae |
| What are the four bacterial agents responsible for meningitis in the neonate? |
Streptococcus agalactiae E. Coli K1 Listeria Monocytogenes Klebsiella pneumoniae |
| What is the number one most important predisposing factor for neonate meningitis? |
| LOW BIRTH WEIGHT |
| What is the etiologic agent for GBS? What kind of bacteria class is it? |
Streptococcus Agalactiae Gram positive cocci |
| What is the leading cause of bacteremia in the first three months of life? |
| Strep Agalactiae; REMEMBER: normal flora |
| The incidence of Group B step is high in which demographic? |
| Pregnant women > 60 years of age? 25% mortality |
| What is the most common form of GBS in the neonate? |
| Early, acute onset sepsis (bacteremia), where the mother is the source |
| What is the less common form of GBS in the neonate? |
Late, insidious onset sepsis. Occurs from 7 days to 3 months of birth. |
| What disease in the "screening approach" effective at reducing the disease a great deal? When is antimicrobial prophylaxis given to the identified (screened) carrier? |
The screening approach is done for carriers of GBS. OR if they were not screened and are delivering prematurely.
Penicillin G or amplicillin is given INTRAPARTUM. Before labor or post-partum will have no effect. |
| In the "nonscreening approach" who is offered antimicrobial therapy? |
Pregnant women that present with risk factors:
elevated temp intrapartum membrane rupture in greater than 18 hours after birth premature onset of labor |
Which agent of neonatal meningitis is described as: **ubiquitous (environment, normal fecal flora, foods) a gram positive cocci can be transferred in utero and transplacentally |
| Listeria Monocytogenes |
A gravid female infected by L. Monocytogenes will manifest with a ______.
They will rarely present with ______?
Why is does the illness occur in the gravid female's 3rd trimester? |
1. Bacteremia 2. Meningitis 3. Greatest decline in mother's CMI |
The fetus infected in utero by L. monocytogenes results in: (other than birth problems)
|
| Early onset sepsis syndrome; fetal mortality rate is high |
Early onset sepsis due to Listeria Monocytogenes (neonatal bacterial meningitis) is associated with?
How is the fetus infected?
What complications may arise? |
Premature births
Fetus is infected in utero by inhaling infected amniotic fluid
Dissemination: abcesses and granulomas in multiple organs |
Where does late onset meningoencephalitis in newborns occur (as opposed to early onset)?
When do S&S manifest?
Is mortality higher or lower than acute onset? |
-late onset occurs during or after birth vs. in utero
Symptoms manifest 1-2 weeks after birth
Mortality is moderate as compared to early onset, however neurological sequelae occur in survivors. |
What type of "test" is done to detect a congenital infection? Name the 4 diseases. |
Toxoplasma Rubella CMV HSV-1 and HSV-2 |
| What is the leading etiologic cause of infection and morbidity in the neonate? |
| CMV |
| Which immunoglobulin do Torch/Storch tests test for? Why? |
| IgM because since IgG crosses the placenta, we need to make sure it's the fetus' blood, not the mother's. |
| What is the most common result of arbovirus infection encephalitis? |
| Asymptomatic infection |
| What is the most common manifestation of poliovirus in focal encephalitis? |
| asymptomatic infection |
| From what animal does half of all the rabies cases come from? |
| Bats |
| Of the 7 agents of bacterial meningitis, which results in the highest mortality rate? |
| Pneumococcal meningitis |
| What are the three focal encephalitis agents? |
| poliovirus, rabies virus, and herpes 1 and 2 |
| In rabies, name the two forms of presentation and the one which is more prevalent |
| The two forms are the furious form (80% of cases) and the paralytic/dumb form )20% |
| most common single pathogen of mass lesions/abcesses in CNS? |
| Staph Aureus |
| Etiologic agent of Neurocysticercosis (NCC)? (also most common parasitic infection of CNS) |
| Taenia solium-cestode/helminth |
| What type of agent is toxoplasma gondii? |
| obligate intracellular protozoan |
| 45% of people in the US are carriers of toxoplasmosis due to ingestion of undercooked food: pseudocysts. Why do many people not show signs and symptoms? |
| Reactivation of latent infection only occurs after immunosuppression of CMI. So AIDS patients are at risk |
| What are the majority of manifestations of toxoplasmosis? |
| Asymptomatic |
| Which disease is described as "cysts spread hematogenously to all organs and tissues where the trophozoites emerge from ruptured macrophages to infect any nucleated cells" |
| Toxoplasmosis |
| Agent of Gastritis? |
| Helicobacter Pylori: gram negative curved rod |
induction of IL-8 -->cancer acid tolerant because it produces copious amounts of urease produces cytotoxin VacA required for ulcers
^these describe virulence factors of which agent?
|
| H. pylori |
| If ulcerdisease is in STOMACH, and not caused by NSAID's, it is probably due to |
| H. pylori |
Epidemiology: -gram negative curved rod -noninvasive -virulence factor: healt-labile enterotoxin -high dose organism (need 1 mil bacteria to infect) -vehicle is shellfish and water -occurs in SUMMER months
Agent?
|
| Vibrio Cholerae |
| Where does V. Cholerae grow? |
| Small intestine |
| Agents of AFEBRILE, WATERY diarrhea (3) |
| Vibrio Cholerae; enterogenic E. coli, Aeromonas |
| enterogetnic E. Coli has same mode of action as cholera, however two differences in manifestations: |
Not as sever and much more abrupt (1-3 days vs. week)
Traveler's diarrhea |
| For vibrio cholera, what causes the disease exactlY? |
| The illness is caused by enterotoxin |
| Name 3 foodborne diseases |
| Staph aureus, Bacillus cereus, and clostridium perfringens type A |
| "acute emetic and diarrheal disease that grows in improperly prepared custard foods and potato salad" is caused by this agent |
| Staph aureus |
Short incubation period entertoxin absorbed in gut acts on vomiting center after dissemination to CNS
^describes pathogenesis of which agent? |
| staph aureus for food-borne illness |
| The emetic form of which agent is very similar to staph aureus' food-borne disease? |
| Bacillus cereus |
| Where are spores for bacillus cereus normally found? |
| rice |
Which of the foodborne diseases are
A. Heat Labile B. Heat Stable C. Heat Labile and Acid labile |
A. Bacillus is heat labile B. Staph aureus is heat stable C. clostridium perfringens is heat and acid labile |
| Bacillus cereus has which two forms of manifestation? |
| EMETIC and diarrheal |
Which of the following are extracellular protozoans, and which are obligate intracellular invasive?
Giardia Cryptosporidium and cyclospora
|
Giardia: extracellular C and C: obligate intracellular invasive
|
| What are the four agents that are intestinal protozoans? |
| Giardia, cyclospora, cryptosporidium, microsporidia |
| Are protozoans low or high dose infectious organisms? |
| They are LOW dose, only needing 10-1000 cysts/oocsysts |
| Most common cause of water-borne outbreaks in US? (swimming pools, water parks, etc) Second? |
1. Cryptosporidium parvum 2. Giardia lamblia |
| Seasonality for protozoan agents |
| late summer, early fall |
| Agent where pt. presents with afebrile water diarrhea with flatulence, abdominal distension, steatorrhea, watery-greasy foul smelling stools due to malabsorption |
| Giardia |
acid fast gents responsible for: afebrile water diarrhea with mucous, flatulence, N+V, abdominal distension.
diarrhea is explosive and self-limiting in immunocompetent. lasts 2 weeks.
diarrhea for 2 months; dissemination to GI tract, liver, pancreas lungs in immunocompromised |
| Cryptosporidium and cylcospora |
| What is the most common cause of HIV diarrhea? |
| enterocytozan (microspordia) |
| Which two agents present with diarrhea with or without fever? |
enterohemorrhagic E. Coli and Shigatoxin-producing ecoli
(EHEC and STEC) |
| Is there bacteria in the blood for STEC and EHEC? |
| NO. Only toxin in blood |
| agent of amoebic dysentery? |
| entamoeba histolytica |
Which form is the infection form in entamoeba?
What shaped formations are found surrounding intestinal mucosa after cell destruction in dysyntery? |
cyst form is infectious
"flask shaped" formations |
| Which agent causes diarrhea and colitus after either broad-spec antibiotic therapy or antacids/PPI's? |
| Clostridium Difficile |
| Which types of people are predisposed to infection by clostridium difficle? |
| elderly > 60 year old females |
| How can you tell the differnce between AAC and AAPMC? |
| AAPMC has more severe, profuse diarrhea, and it prsents with classic yellowish plaques scattered over colonic mucosa* (pseduomembranes) |
| Three agents of VIRAL gastroenteritis (osmotic diarrhea) (all are obligate intracellular) |
-rotavirus -norwalk and noroviruses |
Which is endemic in winter?
Norwalk virus Rotavirus Norovirus |
| Rotavirus |
The following describes which agent?
causes epidemic viral gastroenteritis, occurs primarily in older children and adults; most cases in summer; outbreaks in communities/nursing homes. |
| norwalk/noroviruses |
| Which agent is responsible for 50% of all food-borne gastroenteritis breakouts in US? |
| norovirus |
Name 4 invasive diarrheal agents: (ALL G - rods) |
| Shigella, campylobacter jejuni, yersinia enterocolitica, salmonella |
Shigella, Yersinia, and Salmonella _____ human cells
|
| invade |
| campylobacter, yersinia, and salmonella cause _____________ |
| bacteremia |
| Agent that causes Bacillary Dysentery? |
| Shigella |
For shigella, the sole reservoir is:
For campylobacter, it exists in NF of GIT of ____ |
| humans; chickens |
| leading cause of gastroenteritis world-wide? |
| campylobacter jejuni |
Agent thats virulence factor is similar to ST toxin of ecoli -winter seasonality -transmitted via unpasteurized milk, canned meat, and blood transfusions |
| Yersenia enterocolitica |
| reservoirs principally animals; infection of chicken oviducts, so washing exteral egg won't help. summer/fall seasonality; high dose organism |
| Salmonella |
| Leading cause of seafood-associated fatalaties in the USA? |
| Vibrio parahaemolyticus |
Three Helminth/Tapeworm (cestode) infections?
|
| Taenia saginata, T. solium, and diphyllobothrium latum |
Humans are the definitive/intermediate host Pork Tapeworm can cause cysticercosis |
| Taenia Solium |
| 3 nematode (roundworm agents) |
Enterobius Trichuris trichiura Ascaris |
For three nematodes: Hosts? Which agent is described below: thumbsuckers at risk trouble sleeping at night because females lay eggs at night, cause itching |
humans are only hosts
enterobiasis |
light infections (asymptomatic) heavier infections (symptomatic) systemic symptoms include blood loss |
| Trichuriasis (trichuris trichiura) |
