Test 2 Flashcards

Question

Salmonella typhi is a subspecies for salmonella enterica. What disease does it cause and is it pathogenic?

Answer 1

-pathogenic -causes typhoid fever (enteric fever)

Answer 2

-gram neg bacteria -rod shaped

Answer 3

peritrichous

Answer 4

via fecal oral route through contaminated food or water typhoid Mary worked as a cook and was the first person in US identified as an asymptomaic carrier of this pathogen the ingested organisms reach the small intestine, enter the lymphatics and then enters the blood stream to many organs the organisms multiply in the intestinal lymphoid tissue and are excreted in stools incubation period is 10-14 days bacteria will enter lymphatic tissue in GI and multiply here which can penetrate bowel and cause digestive absorption problems and cause leaky bowel

Answer 5

no not anymore, due to good sanitation practices

Answer 6

-fever -malaise -headache -constipation -myalgia -nausea -abdominal pain -rash called rose spots found on chest and abdomen principle lesions are hyperplasia and necrosis of lymphoid tissue (peyer's patches), hepatitis, necrosis of the liver, and inflammation of the gallbladder and other organs following an infection, 5% continue to harbor and excrete organisms for a year or more without symptoms

Answer 7

-primarily clinical -blood and stool cultures within first week of onset (positive in 85-90% of cases) -PCR test -salmonella shigella (SS) agar favors growth of these organisms over other coliforms -bismuth sulfite medium permits rapid detection of S. typhi, which forms black colonies from production of H2S -widal test is an Ab aggulation test that will build clumps if serum has the bacteria in it -serological testing is not definitive and is used only in poor areas of the world where blood cultures are not readily available

Answer 8

tx: antibiotics prevention: vax for travelers

Answer 9

paratyphoid fever (enteric fever)

Answer 10

both are gram neg rods

Answer 11

-causes enteric fever but the disease is milder and shorter duration than typhoid fever from S. typhi -transmitted by means of contaminated water and food

Answer 12

septicemic enteric fever

Answer 13

gram neg rod

Answer 14

-cattle -poultry -pigs -pets (turtles, parrots, etc) the organisms almost always enters via the oral route, usually with contaminated food or drink

Answer 15

-nausea -diarrhea -abdominal cramping -septicemia tx: antibiotics

Answer 16

salmonella gastroenteritis

Answer 17

gram neg rod

Answer 18

-anal oral route -from contaminated foods that have not been properly cooked or pasteurized like meat, eggs, milk, water, ice cream -most often from poultry -contaminated water can also be a problem -animals are the main reservoir and it affects many animals like poultry, cattle, swine, sheep, rats, dogs, cats, mice, turtles, and birds note: this is an animal disease with humans being secondarily infected

Answer 19

-FBI -bacteria is ingested (its an infection) with limited multiplication and no invasion of host tissue (DOES NOT CAUSE SEPTICEMIA) -bacteria remains in GI -this is unusual for bacteria and overtime can start to produce endotoxins from the cell wall (lipopolysaccharide with lipid A irritates the GI tract and can cause fever) within 6-48 hours of infection S&S: -fever -abdominal pain -diarrhea -nausea -vomiting

Answer 20

salmonella enteritidis (salmonella enterica serotype enteritidis) causes salmonella gastroenteritis

Answer 21

tx: -replacement of electrolytes is usually enough -antibiotics may be needed if severe case prevention: -adequate cooking of meat and boiling water can eliminate the problem

Answer 22

S. dysenteriae causes shigellosis (bacillary dysentery)

Answer 23

gram neg non-motile rod/bacillus

Answer 24

-human intestine is the source -upon recovery a few people may remain as chronic intestinal carriers and may have recurrent bouts of the disease -mode of transmission is fecal oral route via contaminated food or water

Answer 25

-S. dysenteriae is the most severe of the shigella sp. and produces an enterotoxin AND a neurotoxin -inflammation and necrosis of large intestine, but invasion into bloodstream is rare -toxic products of bacterial cell wall (lipid A) irritates causing ulceration with some epithelial cell penetration -disease ranges from mild transient diarrhea to full blown dysentery -inflammation of large intestine is accompanied by gripping pain, constant desire to evacuate the bowels (tenesmus, which means constant need to be on toilet), diarrhea containing blood/mucus/pus -fever, water loss and electrolytes imbalance with weight loss -patients may die 1-2 days after symptoms appear -more commonly, symptoms last about a week, and slowly abate, many cases are self-limiting -the young and old are the most frequent victims

Answer 26

culture organism from feces

Answer 27

-antibiotics -fluid replacement bc of electrolyte imbalance

Answer 28

-gram neg -motile comma shaped rod

Answer 29

-fecal oral route -water borne disease -better sanitation= less frequent cases of cholera -humans are the only host, V. cholera does not affect animals

Answer 30

-not an invasive infection -bacteria does not reach bloodstream, will remain in GI -50% of infections are asymptomatic -for those with symptoms, there is sudden onset of nausea and vomiting and profuse diarrhea with abdominal cramps -the cell wall of V. cholera has an endotoxin which is an enterotoxin that is secreted and results in enormous our-pouring of diarrhea, fluids, and electrolytes -the diarrhea is referred to as RICE STOOLS -this rapid loss of fluid and electrolytes leads to severe dehydration, circulatory collapse (blood volume decreases and heart has to pump faster/harder), and anuria (no urine production) -mortality rate w/o treatment is 25-50%

Answer 31

-water and electrolytes!!!!!! -antibiotics are secondary

Answer 32

infections take longer, whereas toxins can hit within a couple hours and bc the onset is faster, toxins usually are more vomit prone, whereas infections are more diarrhea prone

Answer 33

gastroenteritis (FBI, usually acute)

Answer 34

-gram neg -comma shaped rod

Answer 35

halophile organism

Answer 36

ingestion of contaminated seafood such as raw fish or shellfish, most commonly shellfish

Answer 37

-incubation period of 12-24 hours -N/V, abdominal cramps, fever, and water to blood diarrhea -fecal leukocytes are present -the gastroenteritis tends to subside in 1-4 days w/ no treatment other than restoration of water/electrolyte balance -most common in Asia and other places people eat raw seafood

Answer 38

prevention: adequate cooking of seafood tx: restoration of electrolyte balance

Answer 39

-severe wound infections -bacteremia -gastroenteritis

Answer 40

-gram neg -comma shaped rod -found in oysters/shellfish especially in warm months -commonly infects fishermen

Answer 41

severe wound infections -seen in both normal people and immunocompromised pts who are in contact with infected water -can be mild but progress rapidly with cellulitis, myositis, and necrosis bacteremia -occurs in pts who eat infected oysters -seen in alcoholics or pts with liver disease -about 50% die gastroenteritis -FBI infection often proceeds rapidly with development of severe disease

Answer 42

antibiotics

Answer 43

coliform bacteria

Answer 44

pneumonia and UTIs

Answer 45

-gram neg rod -has prominent capsule which is virulent -bacterial strains w/o capsule do not cause disease -opportunist present in respiratory tract and feces in about 5% of normal people

Answer 46

-acquired by droplets -may cause primary or secondary disease in alcoholics or people with COPD -characterized by rapid onset and gelatinous reddish-brown sputum called red currant jelly

Answer 47

antibiotics

Answer 48

pseudomonas aeruginosa (blue pus organism)

Answer 49

wound and burn infections

Answer 50

-gram neg -motile rod

Answer 51

-normal flora in GI -seen in moist environments like nature and in hospitals (nosocomial infection)

Answer 52

-blue pigment called pyocyanin -wound, environment around it, etc will appear blue -literally called "blue pus'

Answer 53

-pili extend from cell membrane to promote attachment -lipopolysaccharide layer exists in many phenotypes and is responsible for many of the endotoxin properties of organism -most isolates produce exotoxins which may be related to pathogenicity -pathogenic only when introduced into areas devoid of normal defenses like tissue damage, use of IV, urinary caths, or neutropenia is present from chemotherapy -infection is most prevalent in severe burn victims -also implicated in wounds, UTIs and pneumonia particularly in the immunocompromised

Answer 54

-caused by pseudomonas aeruginosa -skin infection of the hair follicles -happens when in contact with contaminated water -can happen in also whirlpools and waterslides, not just hot tubs

Answer 55

diagnosis: culture of specimens tx: combo of antibiotics

Answer 56

-bubonic plague (black death) -septicemic plague -pneumonic plague

Answer 57

-gram neg -rod -zoonotic organism -can be used in bioterrorism -primarily a disease of rodents (reservoirs) like rats and squirrels -flea vector, flea will bite on human and cause infection

Answer 58

-pestilence -great plague -the plague -black plague note: one of the most devastating pandemics in history

Answer 59

bubonic plague -bite of flea initiates infection -bacteria infects lymphatic system and the lymph nodes become inflamed forming buboes (enlarged enflamed lymph nodes) -hemorrhages result in giving skin a black splotchy appearance

Answer 60

-bacteria enters bloodstream rather than lymphatic system -occasionally will start as bubonic plague and then transition into septicemic plague -almost always fatal w/o treatment of antibiotics

Answer 61

-can be caused by primary or secondary infection -primary is inhaling the plague bacteria -secondary is septicemic plague spreading into lung tissue -pneumonic plague is very aggressive -antibiotics are needed within 24hours of onset to prevent death

Answer 62

buboes > thoracic duct > blood > spleen > additional lymph nodes

Answer 63

cultures of blood, lymph nodes, or sputum if culture is neg, then serological testing can be done to confirm diagnosis

Answer 64

prevention: reduce rodents and wear flea repellent tx: antibiotics ASAP

Answer 65

legionnaire's disease (a type of pneumonia)

Answer 66

-gram neg -rod or coccoid shaped -found in warm moist water environments like lakes, streams, etc

Answer 67

-common in immunocompromised -bacteria is inhaled from contaminated AC units, cooling towers, shower heads, residual water systems, etc. -asymptomatic infection is common in all age groups -may result in febrile illness of short duration or in a severe rapidly progressive illness with high fever, malaise, nonproductive cough, and hypoxia -pneumonia may occur -many patients appear disoriented

Answer 68

-can be isolated from bronchial washings and blood -can be cultured on special media at 90% humidity -can use direct fluorescent antibody tests -sometimes antigens will appear in urine

Answer 69

tx: antibiotics prevention: hyper chlorination and superheating of water can help

Answer 70

gastroenteritis and occasionally systemic infection

Answer 71

-gram neg -rod shaped comma or S shaped "gull wing" -microaerophilic (5% O2, 10% CO2) -incubation of plates should be at 42 degrees celcius to discourage growth of most other bacteria present in feces -found in GI

Answer 72

-bacterial infection is acquired by fecal oral route from food, drinks, or contact with infected animals/animal products especially poultry -C. jejuni is susceptible to gastric acid and ingestion of about 10k cells is necessary to produce infection -C. jejuni multiply in the small intestine, invade the epithelium and produce inflammation that results in the disappearance of red/white blood cells in the stools -has acute onset of cramps/abdominal pain, profuse diarrhea that may be bloody, headache, malaise, and fever -usually lasts 5-8 days -certain serotypes of C. jejuni has been associated with Gullain Barre syndrome (many years after infection), which is a form of an ascending paralytic disease

Answer 73

diagnosis: gram stained stool smears and cultures on selective media tx: antibiotics shortens duration of fecal shedding prevention: fully cook meat

Answer 74

-gastritis -duodenal peptic ulcers -gastric ulcers -stomach carcinoma (epithelial tissue cancer) -stomach lymphoma (lymph tissue cancer)

Answer 75

-gram neg -motile spiral shaped -microaerophilic (5% O2, 10% CO2) -found deep in the mucosal layer near the epithelial surface where pH is approx 7.4 -produces urease which further buffers the acidic pH in stomach (increases pH of itself to fight off acidic GI pH)

Answer 76

-nausea, pain, vomiting, and fever -acute symptoms may last for approx 1-2 weeks -after colonization, the H. pylori infections persist for years or decades -about 90% of pts with duodenal ulcers and 50-80% of those with gastric ulcers have H. pylori -H. pylori is also a major risk factor for cancers

Answer 77

-gastric biopsy -gastric culture -antibody assay -breathe test

Answer 78

-antibiotics, treat ulcers -ulcers are treated with anti-acids and antibiotics

Answer 79

-gram neg (this is unusual bc usually anaerobic bacteria is gram pos, in fact this is the ONLY gram neg anaerobic bacteria we have to know) -anaerobic -rods -normal inhabitants of the bowel

Answer 80

-implicated in intra-abdominal infections (disruptions of intestinal wall) -also seen in intra-pelvic infections for pts with PID (pelvic inflammatory disorder) and ovarian abscesses

Answer 81

surgical drainage and antimicrobial therapy

Answer 82

-pneumonia -meningitis (in children) -upper/lower respiratory tract infection (both adults + kids) note: H. influenza is a misname, does not actually cause influenza, but when it was discovered it was thought the pneumonia was influenza

Answer 83

-gran neg -small and encapsulated (which increases virulence) -coccobacillus -non-encapsulated type is found in normal flora of respiratory tract of humans -H. influenza type b (Hib) is an important human pathogen (carrier rate is <1%) -the carrier rate for nontype H. influenza is 50-80% higher

Answer 84

-H. influenza type b (Hib) causes meningitis, pneumonia, and epiglottitis -nontype H. influenza tends to cause chronic bronchitis, otitis media, sinusitis, and conjunctivitis -H. influenza type b (Hib) enters through respiratory tract and may reach bloodstream and is carried to meninges -> causes bacteremia + meningitis

Answer 85

-specimens of sputum or CSF -bacteria cultured on chocolate medium (heated blood) -gram stain of CSF shows neg intracellular coccobacillus -H. influenza requires heated blood for growth to obtain the X factor heme and the V factor NAD >>H. influenza exhibits satellitism on blood agar plates when grown in presence of S. aureus and other organisms >>aka, H. influenza grows next to S. aureus and S. aureus will stimulate growth of V factor

Answer 86

antibiotics hib vax for younger population + military

Answer 87

conjunctivitis (pink eye)

Answer 88

-gram neg -small encapsulated coccobacillus -closely resembles H. influenza

Answer 89

-associated with highly communicable form of conjunctivitis in children -may be mild or serve -infected eye gives sensation of having sand in the eye -mucus or mucopurulent discharge is present (eye boogers)

Answer 90

diagnosis: examination of smears shows gram neg coccobacillus tx: antibiotic eye drops

Answer 91

chancroid STD (resembles syphilis but ulcer is soft and painful whereas syphilis is hard and painless) memory cue: Dr. Lou said H. ducreyi = do cry bc STD is so painful

Answer 92

-gram neg -small encapsulated coccobacillus

Answer 93

- STD caused by H. ducreyi -typically grows in male genitals and causes painful shallow hard ulcer at the site of infection (women can also get it) -starts off as a small bump that becomes an ulcer and grows within a day of its appearance -ulcer will have irregular/ragged borders and the base of it is covered with grayish/yellowish material and can easily bleed

Answer 94

-case history and clinical appearance helps with diagnosis -culture of bacteria from ulcer region is the gold standard, but the media is only 80% sensitive -antibiotic therapy -there is no permanent immunity, meaning its recurring with continual infection -immune system will not remember infection

Answer 95

whooping cough, also known as pertussis

Answer 96

-gram neg -small encapsulated coccobacillus -spreads via respiratory droplets, or carriers -only host is human, has short lifespan outside of host -causes worldwide incidence, but most common in young people

Answer 97

-highly communicable and important pathogen of humans -Bordetella pertussis produces the pertussis toxin which is a secreted exotoxin that increases virulence

Answer 98

1) catarrhal stage -after an incubation of 2 weeks, pt will develop cough and sneezing -bacteria spreads and pt will become highly infectious but not very ill 2) paroxysmal stage -cough develops an explosive character "whoop" upon inhalation -leads to rapid exhaustion, vomiting, cyanosis, and convulsions -secondary invaders like staph and haemophilus may complicate this even more 3) convalescent stage -slow progress of recovery -coughing and whooping may recur for up to a year

Answer 99

-culture using enriched medium >> use cough aerosols on Bordet-Gengou (potato blood glycerol) >> or can use Regan Lowe medium (preferred, due to longer shelf life) -rapid PCR test (excellent sensitivity) -serological assay (more useful for late stages of disease)

Answer 100

-antimicrobial therapy ASAP -DTaP vaccine

Answer 101

1) B. abortus (cattle) 2) B. suis (swine) 3) B. melitensis (goats and sheep) 4) B. canis (canine)

Answer 102

brucellosis, also known as undulant fever or malta fever

Answer 103

-gram neg -rods -aerobic -zoonotic (animals harbor it asymptomatically and transmit to humans) -most common route of infection is unpasteurized cheese from goat milk

Answer 104

routes: 1) intestinal tract (ingestion of infected milk or milk products) 2) mucous membranes (droplets) 3) skin (contact with infected tissues of animals -infection proceeds via lymphatic channels and regional lymph nodes to the thoracic duct, blood stream, and RES (reticuloendothelial system, which includes the liver, spleen, lymph nodes, and BM) -may result in granulomatous nodules -fever, weakness, aches, and sweats -fever appears in waves (usually rises in afternoon (undulant fever) and falls at night), accompanied with night sweats -symptoms can last weeks to months -after initial infection, a chronic stage may develop >>characterized by weakness, aches and pains, and low-grade fever

Answer 105

-liver -spleen -lymph nodes -BM

Answer 106

-blood and biopsy from lymph nodes or BM for culture -serological testing, specifically agglutination test or ELISA test

Answer 107

treatment: prolonged antimicrobial therapy prevention: proper pasteurization of milk and milk products and reduction of occupational hazards with animals

Answer 108

tularemia "rabbit fever"

Answer 109

-gram neg -small coccobacillus -zoonotic (transmitted by arthropods biting humans, flies, direct contact with infected animal tissue, inhalation, or ingestion of contaminated food/water) -hunters are especially at risk -wild animals cannot be controlled

Answer 110

-highly infectious bacteria -routes of infection can be through penetration of skin and mucus membranes or inhalation of 50+ cells -fever, malaise, headache, and pain in the involved region/regional lymph nodes types: 1) ulceroglandular tularemia -bacteria enters through skin abrasions/ulcers -regional lymph nodes enlarge and may become necrotic, sometimes draining for weeks 2) pneumonic tularemia -often lethal w/o treatment -most dangerous type -inhalation of infective aerosols results in bronchial inflammation and localized pneumonitis 3) oculoglandular tularemia -eye infection -can develop when an infected finger or droplet touched the conjunctiva other forms that are less common: -glandular tularemia (lymphadenopathy but no ulcers) -oropharyngeal tularemia (ingested) -typhoidal tularemia (septicemia)

Answer 111

clinical specimens, but mostly serological tests/blood tests tx: antimicrobial therapy

Answer 112

-Francisella tularensis -Yersinia pestis -Bacillus anthracis -Ebola VIRUS, not bacteria

Answer 113

anthrax, also known as wool sorters disease (occupational hazard) or black eschar (bc of black pustules from necrosis)

Answer 114

-gram pos -large rod -aerobic -spore-forming bacteria -has capsule made of proteins (polymer of glutamic acid) -portal of entry is the mouth and GI -primarily disease of herbivores and occupational disease (farmers, vets, butchers, people who work with wool or goat hair or leather)

Answer 115

-infection happens when in contact w/ infected animals or animal products -humans acquire it by entry of spores through injured skin, rarely through GI mucous membranes or by inhalation of spores -B. anthracis produces several toxins routes: 1) cutaneous anthrax -relatively mild, most common type (95% of anthrax infections, 20% will result in death) -skin abrasions w/ spore containing animal products can lead to infections -begins as papule and within 1/2 days it develops into pustule or black necrotic tissue that crusts over -lymph glands in area may be invaded and swell 2) intestinal anthrax -consumption of contaminated and undercooked meat -acute inflammation of GI -results in death in 25-60% of cases 3) inhalation anthrax -most dangerous type, can be used for bioterrorism -usually fatal w/o tx -inhaling spores -workers on tan hides, hear sheep, or process wool may inhale spores -may contract a pneumonia called wool sorters disease -initially resembles common cold, but after a couple days can progress to severe breathing and shock

Answer 116

-fluid or pus specimens from local lesion -blood, pleural fluid, CSF, or stool samples -direct smears with immunofluorescence stain -cultures on blood agar medium -ELISA test for late stages

Answer 117

tx: antimicrobial therapy control measures -disposal of animal carcasses by burning or deep burial in lime pits -decontamination of animal products -protective clothing and gloves for handling potentially infected animals -active immunization for domestic animals with live attenuated vaccine -vaccine is also available to military or other people at risk for repeated exposure

Answer 118

respiratory or cutaneous dipitheria

Answer 119

-gram pos -rod (irregular swellings at one end gives it a club shaped appearance) -aerobic -non-spore forming bacteria -metachromatic granules (nutrient granules stain red w/ blue dye) gives rod a beaded appearance -individual bacteria cell in slides tend to lie parallel or at an acute angle to each other -spread by droplets (respiratory) or direct contact with wounds

Answer 120

-most dangerous type -diphtheria toxin (EXOTOXIN) is absorbed into mucous membranes and causes destruction of epithelium -necrotic epithelium becomes grayish pseudomembrane (most commonly seen over tonsils, pharynx, or larynx) -bacteria continues to grow and will produce more toxins, which will be absorbed into the organs- heart muscle, liver, kidneys, adrenal glands, and sometimes acute hemorrhages -the toxin will also produce nerve damage resulting in paralysis of the soft palate, eye muscles and extremities -begins w/ low grade fever and sore throat -followed by prostration and dyspnea caused by obstruction of the membranes, which will later cause suffocation

Answer 121

-seen on hands, feet, and legs -occurs chiefly in the tropics with humidity -most commonly seen on wounded areas and is usually localized to that area -less severe than the respiratory diphtheria

Answer 122

-cultures from nose, throat, and suspected lesions -PCR test for detection of the toxin

Answer 123

tx: -administration of specific antitoxin to kill the exotoxin -antibiotics prevention: DTaP vaccine (Toxoid vaccine) given to children and young adults

Answer 124

diphtheria, tetanus, whooping cough

Answer 125

tetanus (also known as lockjaw or trismus)

Answer 126

-gram pos -large rod -anaerobic -spore forming (endospores are found in the soil and feces of horses or other animals)

Answer 127

via punctures -nail, needle, wound, etc -infection of umbilical stump in primitive cultures

Answer 128

-incubation period may range from 4/5 days to 4/5 weeks -the vegetative cells produce the toxin tetanospasmin -C. tetani also produces an exotoxin called neurotoxin which fixes to inhibitory neurons -the effect of the neurotoxin is to block the release of inhibitory neurotransmitter GABA and glycine across the synaptic cleft which is required for nerve impulses -the neurotoxin produces a generalized muscular spasm characteristic of tetanus, which is the contraction of voluntary muscles -usually the area of injury or infection is affected first and then the muscles of the jaw, which contract so that the mouth cannot be opened -gradually overtime, other muscles will become involved and result in a tonic spasm -pt will be fully conscious and in pain -death results once respiratory muscles are affected -death rate is relatively high

Answer 129

clinical picture and history of injury

Answer 130

tx: -large doses of antitoxin (tetanus immune globulin) through IV -muscle relaxants -sedation -assisted ventilation prevention: -immunization of tetanus toxoid vaccine (DPT, also known as DTaP) -boosters every 10 years

Answer 131

C. botulinum

Answer 132

botulism (2 types: one is an FBI (infants only) and the other is a toxin)

Answer 133

-gram pos -large rod -anaerobic -spore forming -C. botulinum is a saprobe that is found in soil -botulism is a toxemia (adults only), but also can be a true food poisoning (FBI for infants)

Answer 134

-C. botulinum secretes an exotoxin called neurotoxin under anaerobic conditions -commonly found in home canned foods -the toxin is absorbed by the upper portion of GI tract and in the duodenum and jejunum -the neurotoxin passes into bloodstream and reaches the peripheral NMJ/synapse and binds to the presynaptic terminals -the toxin blocks the release of the neurotransmitter ACh which is required to stimulate the muscles -this causes flaccid paralysis of the involuntary muscles

Answer 135

-flaccid paralysis of the involuntary muscles -prior to paralysis pt will have double vision bc the eyes muscles are the smallest and have least amount of ACh, so when it gets inhibited eyes go first -blurred vision -drooping eyelids -slurred speech -difficulty swallowing -dry mouth -muscle weakness -death occurs from respiratory paralysis or cardiac arrest note: all these symptoms are related to decreased muscle function because ACh is inhibited

Answer 136

-most frequent cause of infection is spores in honey -spores germinate in GI after ingestion -not a toxemia like in adults, but rather a true food poisoning FBI

Answer 137

prevention: -canned foods need to be boiled for at least 20 min before consumption bc C. botulinum is a heat liable toxin, meaning it can be destroyed tx: -trivalent antitoxin ASAP through IV -mechanical ventilation

Answer 138

-gas gangrene -FBI

Answer 139

-gram pos -large rod -anaerobic -spore forming -C. perfringens and related clostridia can produce invasive infections including myonecrosis and gas gangrene

Answer 140

-C. perfringens infects deep wounds that are contaminated by soil or feces -found in soil -some strains produce a powerful exotoxin especially when grown in meat dishes

Answer 141

-C. perfringens produces several powerful exotoxins that can diffuse out of the contaminated wound into the host and may cause death -the spores germinated, vegetative cells multiply, and ferment carbs present in tissues and produce gas -the distention of tissue and interference of blood supply, together with the toxins favors the spread of infection -tissue necrosis extends outwards and provides opportunity to increase even more bacterial growth -will cause hemolytic anemia, severe toxemia, and death -incubation period is 8-48 hours -C. perfringens FBI usually follows the ingestion of large numbers of clostrida in warm meat dishes -the toxin forms in the gut, resulting in vomiting and diarrhea for 1-2 days

Answer 142

diagnosis -clinical picture and isolation of the organisms from wounds, pus, tissue tx: -surgical debridement of the area and removal of all devitalized tissue -antimicrobial therapy -hyperbaric oxygen

Answer 143

pseudomembranous colitis

Answer 144

-gram pos -large rod -anaerobic -spore forming -most commonly affects older adults in hospitals or long term care facilities -typically occurs after long term use of antibiotics (2+ weeks, this is bc normal flora is all gone now so theres plenty of room for C. diff to grow) -can be an opportunistic infection

Answer 145

-C. diff produces 2 toxins -one of the toxins is called enterotoxin, which cause fluid loss -the other toxin is a cytotoxin which causes further mucosal damage -symptoms can be mild-moderate -watery diarrhea 3+ times a day for 2+ days, mild abdominal cramping and tenderness -symptoms can also be more severe -watery diarrhea 10-15x a day, severe abdominal pain and cramping, fever, blood or pus in stool, nausea, dehydration, kidney failure

Answer 146

-ampicillin -clindamycin -any fluoroquinolones

Answer 147

-detection of either toxins in stool -endoscopic observation of pseudomembranous colitis -clinical evidence of micro-abscesses

Answer 148

-discontinue use of antibiotics -start metronidazole or vancomycin (antimicrobials) -fecal microbiota transplantation (FMT, also known as fecal transplant)

Answer 149

broad spectrum -kills widespread of bacteria and many different types -also kills all the normal flora narrow spectrum -kills a specific bacteria or only a few types

Answer 150

tuberculosis (TB)

Answer 151

-trick question- its an acid fact bacilli -resists decolorization by acids or alcohol

Answer 152

-minorities -immigrants from countries with high endemicity -HIV pts -homeless people -young and old people

Answer 153

-humans who excrete large amounts of tubercle bacilli from respiratory tract -close contacts in family or massive exposure like medial personnel make transmission by droplet nuclei most likely -disease only occurs in a small population of infected individuals

Answer 154

-virulent strains contain cord factor (mycolic acid) around cell -M. tuberculosis is emitted in droplets when infected person coughs, sneezes, or speaks -droplets evaporate and make it into alveoli -M. tuberculosis replicates within macrophages -1-2 months after exposure, pathogenic lesions are associated with infection and appear in the lungs -tubercle bacilli spread in the host through the lymphatic channels and bloodstream and via the bronchi and GI tract -chronic disease that advances slowly types of lesions: 1) exudative lesions 2) productive lesions types of infections: 1) primary infection type of TB -host has first contact with tubercle bacilli -a lesion develops and spreads to the lymphatics and regional lymph nodes -lesion in tissue often heals quickly -lesion calcifies and tuberculin test becomes positive 2) reactive type of TB -had TB in past -usually caused by bacilli that have survuved in the primary lesion -characterized by chronic tissue lesions, formation of tubercles, and fibrosis symptoms -fatigue -weakness -weight less -fever/ night sweats (fever in afternoon, night sweats in evening) -chronic cough with blood in sputum atypical manifestations -lupus vulgaris = cutaneous TB -miliary TB = disseminated throughout the body, lesions resemble millet seeds -TB in bone

Answer 155

-staining os sputum specimen using Ziehl-Neelsen (acid fast stain) -X-ray -Tuberculin skin tests >>mantoux, PPD (more specific), or tine skin tests >> can detect past or present TB -TB blood tests are called interferon gamma release assays (IGRAs), pos test= infected with TB -blood tests are preferred for people who have gotten skin test in past

Answer 156

-specific chemotherapy with INH (isoniazid) and usually RMP (rifampin) but can be something else paired with INH -bacille calmette-guerin (BCG) vaccine protects against meningitis and TB in children from recurring, but this is not commonly used in US NOTE: if vaccinated with BCG, then mantoux skin test will appear positive

Answer 157

TB in humans and cattle

Answer 158

-milder form of TB than the one caused by M. tuberculosis -less than 2% of TB cases in US -human infection normally through consuming unpasteurized milk or its products -if inhaled, M. bovis has the ability to produce pulmonary disease indistinguishable from M. tuberculosis TB (only can tell difference through blood work)

Answer 159

-antibiotics and chemotherapy -elimination of diseased cattle -pasteurization of milk products note: mantoux skin test can distinguish between past or present infection, BUT if you're vaccinated with BCG then mantoux skin test will be positive

Answer 160

leprosy, also known as Hansen's disease

Answer 161

acid fast, M. tuberculosis

Answer 162

-naturally infected armadilos can transmit to humans, but is rare -nasal secretions spread through family is the more common route of transmission -affects small children the most, who have been exposed for prolonged periods to heavy shedders of bacilli -incubation period is 2-10 years -lesions involve cooler tissues -neurological disturbances are manifested by nerve infiltration and thickening with resultant anesthesia and shortening of the digits -disfigurement caused by nerve involvement if left untreated may be severe -2 major types: lepromatous and tuberculoid (lepromatous can be seen and isolated on skin scrapings, but tuberculoid cannot)

Answer 163

diagnosis: lepromin skin test prevention -thorough disinfection of contaminated articles -avoid contact with body fluids and rashes of people with leprosy -genetic testing- several genes have been associated with susceptibility to leprosy tx -sulfones drugs like dapspme is the first line of therapy -may need to take meds for years

Answer 164

primary atypical pneumonia (walking pneumonia- called this bc it will not make you tired/sleepy like typical pneumonia)

Answer 165

M. pneumonia

Answer 166

M. pneumonia

Answer 167

lacks a rigid cell wall

Answer 168

-pathology does not match clinical symptoms -most common in children and young adults -transmitted person to person by means of respiratory secretions -generally a mild disease -can be asymptomatic, moderate symptoms, or have serious pneumonitis -incubation period is 1-3 weeks -onset is insidious with malaise, fever, headache, sore throat, cough -lasts 2-3 weeks usually and recovery is gradual

Answer 169

-usually self limiting -most antibiotics are not helpful -cold hemogglutinins (cold agglutinins) appear in about 50% of patients, which are Abs that agglutinate with RBCs at 2 degrees C

Answer 170

-pleomorphic coccobacilli -small obligate intracellular bacteria (needs host to survive, usually bacteria is extracellular) -transmitted to humans by arthropod vectors -typically manifested by fever, rashes, and vasculitis (can also lead to hemorrhages) -all illnesses can be treated with doxycycline or chloramphenicol

Answer 171

rocky mountain spotted fever

Answer 172

-caused by Rickettsia rickettsia -children are the primary victims -contracted via a tick bite (tick is infected) -tick is attached for 4+ hours and is able to transmit Rickettsia rickettsia -commonly seen in wild mammal and bird popluations

Answer 173

-symptoms present within a week of tick bite -rocky mountain spotty fever is only when pt has febrile illness, hx of potential tick exposure, travel to endemic area, presentation in spring or fall -the classic triad is= fever, headache, and rash -rash is on the palms of hands and soles of feet -The rash is a maculopapular rash that appears 2-6 days after onset of fever and progresses through stages -the absence of delayed appearance of rash increases difficulty of diagnosis -organism proliferates in the endothelium of small blood vessels and capillaries causing small hemorrhages and occasionally small areas of necrosis

Answer 174

-no tests are rapid or sensitive to be fully effective -medical history and clinical exam -serological assays are mostly used to confirm diagnosis after treatment has already been initiated -direct fluorescence Ab assay of Rickettsia rickettsia in tissue is done -can also do PCR -Weil Felix agglutination reaction test uses pats serum and prosteus strain OX19

Answer 175

tetracyclines, like doxycycline

Answer 176

epidemic, endemic

Answer 177

epidemic typhus (louse borne, louse is singular for lice)

Answer 178

-a disease of substandard living conditions and poor sanitation -occurs in colder mountainous regions -occurs with overcrowding and poor hygiene -transmitted through louse vector to humans -can also be found in flying squirrels

Answer 179

-longer duration than the typhus caused by R. typhi -overwhelming bacteremia with growth in blood vessel endothelium (vasculitis), high fever -systemic infection and prostration are severe and fever lasts for about 2 weeks -fatality rate is up to 30% -Brill-Zinsser disease is a recrudescence of an old typhus infection and bacteria can persist for years in lymph nodes without any symptoms

Answer 180

-serological tests such as indirect immunofluorescence and enzyme assays -antimicrobial treatment

Answer 181

endemic typhus (murine typhus)

Answer 182

-shorter duration/milder form than the typhus caused by R. prowazekii -rat flea reservoir -common in high rat infested areas -antibiotics can be used, and rats need to be controlled

Answer 183

1) Vibrio cholera 2) Vibrio parahemolyticus 3) Vibrio vulnificus

Answer 184

1) Haemophilus influenza 2) Haemophilus aegyptius 3) Haemophilus ducreyi

Answer 185

1) clostridium tetanus 2) clostridium botulinum 3) clostridium perfringins 4) clostridium difficile

Answer 186

1) mycobacterium tuberculosis 2) mycobacterium bovis 3) mycobacterium leprae

Test 2 Flashcards

(220 cards)