Spirals

Question 2

Campylobacter

Answer 2

Gram negative rods, “gull wing” shaped spiral bacteria, microaerophiles, fastidius (like blood agar), motile (flagella), grow on MacConkey, non-fermentative, oxidase +. Commensals of GIT in animals. Pathogens of reproductive and enteric tracts.

Question 3

Campylobacter fetus subspp. fetus

Answer 3

Sporatic abortion in cattle/sheep. Transmission through contaminated feed (pasture) or water, bacteremia and spread to other tissue like placenta, causing abortion. S-layer - high molecular weight outer layer. Serum resistant: Protects bacteria by prevention of complement binding and prevention of phagocytosis; also shields antigenic LPS layer. Different than capsule (polysaccharide).

Question 4

Campylobacter fetus subspp. venerealis

Answer 4

Sexually transmitted dz of cattle. Ascending infection from vagina to oviducts. Temporary infertility. Antibodies (IgG, IgA) protect. Abortion in only small percentage of cattle (

Question 5

Campylobacter jejuni

Answer 5

Acute diarrhea in puppies (watery +/- blood). Zoonotic. May be spread by healthy animals that show no symptoms. Invasive Inflammatory Diarrhea Disease. Inflammation and hemorrhage of colon. High amount of mucous production = mucous in diarrhea. Normal flora in birds = no disease association. Normal flora in pigs also.

Question 6

Diagnosis of Campylobacter

Answer 6

Require microaerophilic conditions - 6% oxygen, 84% nitrogen. Stain with dilute carbol fuchsin for 4 minutes - stains more intensely than gram staining. Antibiotic susceptibility patterns.

Question 7

Helicobacter pylori

Answer 7

Gram negative rods, spiral flexible, flagellae, catalase+, urease+, fastidius, microaerophilic. Colonize gastric mucosa and induce inflammatory response (chronic active gastritis) leading to gasatric and duodenal ulcers. Also a known carcinogen. Urease hydrolyzes urea in stomach to ammonia = neutralizing pH, allowing organism to live in stomach. Superoxide dismutase and catalase minimize oxidative damage to the organism from superoxides produced by inflammatory cells.

Question 8

Spirochetes

Answer 8

Includes Borrelia, Leptospira, Brachyspira. Spiral gram-negative rods, motile (endoflagella - curls around body within outer envelope), fastidius. Many are Zoonotic

Question 9

Borrelia

Answer 9

Largest of the spirochetes (gram neg, motile, fastidius), aerobic/microaerophilic. Live in blood, transmitted by ticks (essential). Lyme disease, arthritis/neuro/cardiac dz in dogs. PCR best to ID (genetic differences from other spirochetes).

Question 10

Borrelia burgdorferi in man

Answer 10

Tick transmitted, causes Lyme disease. 1st stage - skin signs from days to weeks after bite. Erythema migrans: multiplication in skin then quickly enter circulation. 2nd stage - musculoskeletal (joint, muscle pains), cardiac damage, rarely CNS signs. Abx therapy successful for primary dz but need to treat early and for an extended period of time (4 weeks). Secondary/tertiary dz sees damage to tissue that abx wont fix.

Question 11

Borrelia burdgorferi in dogs

Answer 11

Tick transmitted, Lyme disease. Also intrauterine transmission. Sudden onset - lethargy, fever, swollen LN, arthritis. CNS infection - cervical pain, depression, anorexia, seizures. Acute renal disease - Lyme-specific immune complexes, complement deposition in glomeruli. Abx therapy successful for primary dz but need to treat early and for an extended period of time (4 weeks). Secondary/tertiary dz sees damage to tissue that abx wont fix.

Question 12

Epidemiology of Borrelia burgdorferi

Answer 12

Encroachment into habitat of deer. Tick spread from deer/mice to humans/dogs. Since spirochetes need to migrate from midgut of tick to salivary gland when feeding on host, the length of time it stays attached is important. It usually takes 24-48 hours for the spirochetes to migrate so short term tick exposure decreases chance of getting infection. Intrauterine transmission in dogs also possible.

Question 13

Leptospira

Answer 13

Fine, tightly coiled spirochetes (smallest of the spirochetes) with hooked ends, aerobic, fastidius. Classified by DNA. Zoonotic; rodents and domestic animals. Host adapted and non-host adapted.

Question 14

Epidemiology of Leptospira - animals

Answer 14

Host adapted: relatively mild dz; venereal transmission; lifelong colonization of genetourinary tract. Non-host adapted: catastrophic infections; abortion storms; carrier state brief.

Question 15

Epidemiology of Leptospira - humans

Answer 15

Temperate climates; infection via direct contact (animal urine, contaminated water source, farm equipment) through moist softened skin or mucous membranes, then circulation through blood stream. Some organisms may evade the immune response and stay in renal tubules mainly.

Question 16

Pathogenesis of Leptospira

Answer 16

After entrance through cuts, moist soft skin, conjunctiva, and other mucous membranes the spirochetes evade local defenses and cause bacteremia. Bacteremia can be short (host-adapted) or longer (non host adapted). Proliferation in liver, kidneys, spleen, meninges. Antibodies, complement eliminate lepto from bloodstream and tissues other than brain, eye, kidneys.

Question 17

Leptospira diseases of veterinary importance

Answer 17

Species of importance: L interrogans, L. borgpetersenii Dogs: host adaptive strain - mild disease, infertility, weak pups. Non-host adaptive - fever, bloody vomit, vascular damage DIC, shock, petechial hemorrhage, nephritis (acute leading to chronic) and renal failure Cattle: host adaptive strain - sporadic abortions, infertility, mild clinical signs. Non-host adaptive - fever, icterus, hemoglobinuria, abortion storms. Swine: host adaptive strain - mild like cattle. Non-host adaptive - similar, plus anemia, meningoencephalitis, death. Horse: similar

Question 18

Brachyspira

Answer 18

Large spirochetes (size between lepto and borrelia), ANAEROBIC, varying amounts of beta hemolysis, indole spot test + (breakdown of tryptophan to indole). Found in intestinal tract (large intestine). Important pathogen in pigs. Cause inflammation, diarrhea, dysentery (acute small volume bloody diarrhea with inflammation). Dx - clinical signs, history; blood agar with abx incubated anaerobically at 42 C. Clearly visible in Gram stained smears.