52 Matching Annotations
  1. May 2017
    1. Campylobacter jejuni is known to possess a LuxS/ autoinducer-2 (AI-2) mediated system that have been partially characterized over the last decade

      quorum sensing

    1. To initiate infection the organism must penetrate the gastrointestinal mucus, which it does by using its high motility and spiral shape. The bacteria must then adhere to the gut enterocytes and once adhered can then induce diarrhoea by toxin release.

      adherence

    1. Campylobacter species also produce the bacterial toxin cytolethal distending toxin (CDT), which produces a cell block at the G2 stage preceding mitosis. CDT inhibits cellular and humoral immunity via destruction of immune response cells and necrosis of epithelial-type cells and fibroblasts involved in the repair of lesions.

      Prevents cells from growing/replicating, destroys immune response and slows down body's recovery and repair

    2. Cytotoxin production has been reported in Campylobacter strains from patients with bloody diarrhea

      there was blood present

    3. Infection with the organism produces diffuse, bloody, edematous, and exudative enteritis

      lovely

    4. C jejuni appears to invade and destroy epithelial cells. C jejuni are attracted to mucus and fucose in bile, and the flagella may be important in both chemotaxis and adherence to epithelial cells or mucus. Adherence may also involve lipopolysaccharides or other outer membrane components. Such adherence would promote gut colonization. PEB 1 is a superficial antigen that appears to be a major adhesin and is conserved among C jejuni strains.

      attracted to mucus membranes

    5. Chickens may account for 50-70% of human Campylobacter infections.

      Most commonly found in poultry

    1. Macrolide resistance in Campylobacter is mainly associated with target modification and active efflux [55–59]. Modification of the ribosomal target, leading to macrolide resistance in Campylobacter, can occur either by enzyme-mediated methylation or by point mutation in the 23S rRNA and/or ribosomal proteins L4 and L22

      A point mutation can also edit the target ribosomal area that macrolides target, adding another level of resistance.

    2. In addition to the mutations in GyrA, the multidrug efflux pump, CmeABC, also contributes to FQ resistance by reducing the accumulation of the agents in Campylobacter cells

      For FQ's, there are two separate pathways of resistance. All other drugs that Campylobacter is resistant to are dealth with through the efflux pump

    3. In Campylobacter, the resistance to FQs is mainly mediated by point mutations in the quinolone resistance-determining region (QRDR) of DNA gyrase A (GyrA)

      Essentially, the DNA gyrase in mutated (resistant) campylobacter strains can still work in the presence of fluoroquinolones. FQs inhibit transcription by keeping the DNA strands together, rather than allowing topoisomerase and gyrase to unzip them.

    4. Generally, the prevalence of erythromycin resistance among Campylobacter strains (including both C. jejuni and Campylobacter coli) isolated from humans, broilers and cattle in the USA and Canada has been reported at 10% or lowe

      Ethrythromycin is the best antibiotic option because it has the lowest reported resistance -- 10% or lower

    5. 19–47% of Campylobacter strains isolated from humans were resistant to ciprofloxacin [

      47%

    6. Alternative drugs include tetracyclines and gentamicin, which are used in cases of systemic infection with Campylobacter [5]. However, Campylobacter is increasingly resistant to the clinically important antibiotics and this rising resistance is a concern for public health.

      Tetracycline can also be used

    1. Cefoperazone is added to inhibit many gram-positive and gram-negative organisms, both aerobic and anaerobic. Vancomycin inhibits gram-positive microorganisms. Amphotericin B is incorporated to inhibit the growth of yeast.

      Added to media

    2. Campy CVA is recommended. The use of cefoperazone-containing media, as opposed to cephalothin-containing media, is recommended for the primary isolation of Campylobacter from fecal samples

      Uses an antibiotic to filter out other fecal flora

    3. C. jejuni continues to be the most common enteric pathogen isolated form patients with diarrhea

      most common

    1. In Campylobacter, a recurring theme is synergy between antibiotic efflux and a second mechanism.

      Resistance mechanism: efflux pumps and a possible second mechanism

    1. Azithromycin therapy would be a primary antibiotic choice for Campylobacter infections, when indicated (see Medical Care), [20] with a typical regimen of 500 mg/d for 3 days. However, erythromycin is the classic antibiotic of choice. Its resistance remains low, [21] and it can be used in pregnant women and children

      Azithro or Erythro

    1. being able to execute N-linked glycosylation of more than 30 proteins related to colonization, adherence, and invasion. Moreover, the flagellum is not only depicted to facilitate motility but as well secretion of Campylobacter invasive antigens (Cia). The only toxin of C. jejuni, the so-called cytolethal distending toxin (CdtA,B,C), seems to be important for cell cycle control and induction of host cell apoptosis and has been recognized as a major pathogenicity-associated factor. In contrast to other diarrhoea-causing bacteria, no other classical virulence factors have yet been identified in C. jejuni.

      virulence

    1. The bacteria colonize the small and large intestines, causing inflammatory diarrhea with fever. Stools contain leukocytes and blood. The role of toxins in pathogenesis is unclear.

      Bacteria colonizes in the intestines

    1. Many types of media have been used to culture C. jejuni. Mueller-Hinton medium, blood agar, Columbia blood agar, and BBL medium are commonly used. However, Mueller Hinton (MH) has the highest recovery rate and is recommended in this unit

      Mueller-Hinton medium

    2. C. jejuni is also able to grow in anaerobic conditions.

      Anaerobic growth :)

    3. Significant loss of viable bacteria occurs when the bacteria are left at room temperature and atmosphere for only 10 min.

      Other growth conditions

    1. All Campylobacter species are inherently resistant to vancomycin, rifampin, and trimethoprim.

      no Vanc

    2. Erythromycin has once again come to be considered the optimal drug for treatment of Campylobacter infections. Despite decades of use, the rate of resistance of Campylobacter to erythromycin remains quite low. Other advantages of erythromycin include its low cost, safety, ease of administration, and narrow spectrum of activity. Unlike the fluoroquinolones and tetracyclines, erythromycin may be administered safely to children and pregnant women and is less likely than many agents to exert an inhibitory effect on other fecal flora.

      Erythromycin!

    3. However, in the past few years, a rapidly increasing proportion of Campylobacter strains all over the world have been found to be fluoroquinolone-resistant
    4. Maintenance of hydration and electrolyte balance, not antibiotic treatment, is the cornerstone of treatment for Campylobacter
    5. contaminated water, contact with pets (especially birds and cats)
    6. Fecal leukocytes and RBCs are detected in the stools of 75% of infected persons

      Stool tested positive for blood

    7. Clinically, Campylobacter infection is indistinguishable from acute gastrointestinal infections produced by other bacterial pathogens, such as Salmonella, Shigella, and Yersinia species.

      :(

    8. They grow best at 42°C. Because most Campylobacter species are resistant to cephalothin (an agent to which most other stool flora are susceptible), the usual method for isolation from stool samples is use of a medium that contains cephalothin.

      Isolation media

    9. Campylobacter species are motile by means of unipolar or bipolar flagellae. The organisms grow quite slowly; 72–96 h are required for primary isolation from stool samples

      3-4 days for lab growth

    10. ampylobacter infections were found to cause diarrheal disease >2–7 times as frequently as infections with Salmonella species, Shigella species, or Escherichia coli O157:H7

      Campylobacter is the most common cause of diarrheal diseases

    11. Obtaining cultures of the organism from stool samples remains the best way to diagnose this infection

      Culture is the best way to diagnose

    1. Azithromycin and fluoroquinolones (e.g., ciprofloxacin) are commonly used for treatment of these infections, but resistance to fluoroquinolones is common. Antimicrobial susceptibility testing can help guide appropriate therapy.

      Although fluoroquinolones are what is typically used, there is frequently reported resistance

    2. What are public health agencies doing to prevent or control campylobacteriosis?

      Public health: food safety

    3. Do not drink unpasteurized milk or untreated surface water.

      water

    4. Surface water and mountain streams can become contaminated from infected feces from cows or wild birds.

      The water used in the tough mudder was probably rivier or stream water, which could easily be contaminated with animal feces.

    5. Most cases of campylobacteriosis are associated with eating raw or undercooked poultry meat or from cross-contamination of other foods by these items. Outbreaks of Campylobacter have most often been associated with unpasteurized dairy products, contaminated water, poultry, and produce. Animals can also be infected, and some people get infected from contact with the stool of an ill dog or cat.

      Contaminated water in the mud used in the tough mudder race.

    6. Almost all persons infected with Campylobacter recover without any specific treatment. Patients should drink extra fluids as long as the diarrhea lasts. Antimicrobial therapy is warranted only for patients with severe disease or those at high risk for severe disease

      Your immune system will do all the work for you. Essentially, no antibiotics needed unless the doctor thinks you could have serious complications (the patient is immunocompromised or very young)

    7. Campylobacter jejuni grows best at 37°C to 42°C, the approximate body temperature of a bird (41°C to 42°C), and seems to be well adapted to birds, who carry it without becoming ill. These bacteria are fragile. They cannot tolerate drying and can be killed by oxygen. They grow only in places with less oxygen than the amount in the atmosphere. Freezing reduces the number of Campylobacter bacteria on raw meat.

      Carried by birds (birds do not become sick with this illness) , like warm temperatures, and cannot be an environment that is either too dry or has too much oxygen in it.

    8. The organism is isolated from infants and young adults more frequently than from persons in other age groups and from males more frequently than females.

      Our patient is both a male and a young adult

    9. The diarrhea may be bloody

      Tested positive for blood

    10. Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain, and fever within two to five days after exposure to the organism.

      Our patient started having symptoms on Monday after participating in the tough mudder on Saturday -- 2 days

    11. How do people get infected with this germ?

      Where is this organism found

    1. nonspore-forming, Gram-negative, microaerophilic, nonfermenting bacterium

      Needs oxygen to live

    2. The vast majority of cases occur as isolated events, not as part of recognized outbreaks.

      is 41 people who are sick from the tough mudder considered an outbreak?

    3. grow optimally at 37 to 42 °C.[5][6][7][8] When exposed to atmospheric oxygen, C. jejuni is able to change into a coccal form

      growing conditions

    4. oxidase-positive

      oxidase test

    5. C. jejuni is also commonly found in animal feces.

      where it's found

    6. 14 cases are diagnosed each year for each 100,000 persons in the population.

      prevalence rate

    1. bacteria are found naturally in the intestines of poultry, cattle, swine, rodents, wild birds and household pets like cats and dogs. The bacteria have also been found in untreated surface water (caused by fecal matter in the environment) and manure.

      Where it is found