85 Matching Annotations
  1. May 2017
    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 jejuni isolates (47.5%). Production of β-lactamase was typically associated with resistance to ampicillin, amoxicillin (amoxicilline), penicillin, and ticarcillin.

      prevalence of ß-lactam resistance in C. jejuni

    1. Here, we analyzed the antimicrobial susceptibilities of 320 C. jejuni and 115 C. coli isolates obtained from feedlot cattle farms in multiple states in the U.S. The results indicate that fluoroquinolone resistance reached to 35.4% in C. jejuni and 74.4% in C. coli, which are significantly higher than those previously reported in the U.S.

      resistance to flouroquinolones in C. jejuni

    1. The organism is unusual among enteric pathogens in that it expresses a polysaccharide capsule (CPS) that contributes to serum resistance, invasion of intestinal epithelial cells in vitro, and virulence in ferret and Galleria mellonella larvae models of disease (1–3).

      CPS in C. jejuni

    1. the mucus overlying the epithelial cells primarily in the ceca and the small intestine but may also be recovered from elsewhere in the gut and from the spleen and liver

      colonization of the musocal cells in small intestine

    1. 14 cases are diagnosed each year for each 100,000 persons in the population. Many more cases go undiagnosed or unreported, and campylobacteriosis is estimated to affect over 1.3 million persons every year.

      prevalence

    2. 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

      Antibiotics used

    3. 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

    4. 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.

    5. 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)

    6. 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.

    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. 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

    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. 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. 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. Azithromycin prevents bacteria from growing by interfering with their protein synthesis. It binds to the 50S subunit of the bacterial ribosome, thus inhibiting translation of mRNA. Nucleic acid synthesis is not affected.[18]

      Mechanism of action

    1. Most people with campylobacteriosis develop the following symptoms two to five days after being infected (though symptoms can appear as late as one month after infection): diarrhea (often bloody or watery) abdominal pain fever nausea vomiting (sometimes)

      Symptoms and timeline

    2. 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

    1. Multiple types of media can be used to cultivate it; however, Mueller Hinton broth and agar support the best C. jejuni growth. Optimum atmosphere for C. jejuni is 85% N2, 10% CO2, and 5% O2.

      Lab conditions.

    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. it has been connected with bacterial gastroenteritis as well as the neurological disorders Guillen-Barré Syndrome and Fisher Syndrome in humans. It is now one of the leading causes of gastroenteritis in both the developed and developing worlds.

      dangers of this bacteria

    2. microaerophilic conditions with a temperature range between 37° and 42°C. Multiple types of media can be used to cultivate it; however, Mueller Hinton broth and agar support the best C. jejuni growth. Optimum atmosphere for C. jejuni is 85% N2, 10% CO2, and 5% O2.

      growth conditions

    1. 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!

    1. he bacteria must then adhere to the gut enterocytes and can then induce diarrhea by toxin release. C. jejuni releases several different toxins, mainly enterotoxin and cytotoxins, which vary from strain to strain and correlate with the severity of the enteritis.

      Releases toxins that make us sick

    1. Temperature range: 30-50°C (86-122°F) Optimum Temperature: 42°C (108°F) pH range: 4.9-9.0 Optimum pH: 6.5-7.5 Oxygen Requirement: 3-5% Carbon Dioxide Requirement: 2-10% Optimum Requirements: 5% Oxygen, 10% Carbon Dioxide, 85% Nitrogen Salt Tolerance: 1.0%

      Growth Conditions

    1. Our results showed that when C. jejuni cells were coincubated with Acanthamoeba polyphaga in acidified phosphate-buffered saline (PBS) or tap water, the bacteria could tolerate pHs far below those in their normal range, even surviving at pH 4 for 20 h and at pH 2 for 5 h. Interestingly, moderately acidic conditions (pH 4 and 5) were shown to trigger C. jejuni motility as well as to increase adhesion/internalization of bacteria into A. polyphaga. Taken together, the results suggest that protozoa may act as protective hosts against harsh conditions and might be a potential risk factor for C. jejuni infections.

      how Campylobacter jejuni survive low pH environments

    1. Skirrow’s Campylobacter Medium (contains polymixin B, trimethoprim, vancomycin) ·   Preston Campylobacter Medium (contains polymixin B, rifampicin, trimethoprim) ·   Campy Blood Agar ·   CVA Medium (contains cefoperazone, vancomycin, amphotericin) Selective media for Campylobacter jejuni

      Lab specific test for Campylobacter jejuni