101 Matching Annotations
  1. Jun 2017
  2. May 2017
    1. Treatment for Uncomplicated UTIs UTIs in low-risk women can often be successfully treated over the phone. In such cases, a health professional provides the patients with 3-day antibiotic regimens without requiring an office urine test. This course is recommended only for women at low risk for recurrent infection, who do not have symptoms (such as vaginitis) suggesting other problems. Antibiotic Regimen . Oral antibiotic treatment cures 94% of uncomplicated urinary tract infections, although the rate of recurrence remains high. The following antibiotics are commonly used for uncomplicated UTIs: The standard regimen has traditionally been a 3-day course of trimethoprim-sulfamethoxazole, commonly called TMP-SMX (Bactrim, Cotrim, Septra). TMP-SMX combines an antibiotic with a sulfa drug. A single dose of TMP-SMX is sometimes prescribed in mild cases, but cure rates are generally lower than with 3-day regimens. Allergies to sulfa are common and may be serious. Fluoroquinolone antibiotics, also called quinolones, have usually been a second choice. However, in geographic areas that have a high resistance to TMP-SMX, quinolones are now the first-line treatment for UTIs. Ciprofloxacin (Cipro) is the quinolone antibiotic most commonly prescribed. Quinolones are usually given over a 3-day period. Pregnant women should not take these drugs. Nitrofurantoin (Furadantin, Macrodantin) is a third option. This drug must be given for longer than 3 days. Fosfomycin (Monurol) is not as effective as other antibiotics but may be used during pregnancy. Resistance rates to this drug are very low. Other antibiotics may also be used, including amoxicillin (with or without clavulanate) and cephalosporins. Doxycycline is often effective but cannot be given to children or pregnant women.

      treatment

    2. Escherichia (E.) coli is responsible for most uncomplicated cystitis cases in women, especially in younger women. E. coli is generally a harmless microorganism originating in the intestines. If it spreads to the vaginal opening, it may invade and colonize the bladder, causing an infection. The spread of E. coli to the vaginal opening most commonly occurs when women or girls wipe themselves from back to front after urinating, or after sexual activity. Staphylococcus saprophyticus accounts for 5 - 15% of UTIs, mostly in younger women. Klebsiella , Enterococci bacteria, and Proteus mirabilis account for most of remaining bacterial organisms that cause UTIs. They are generally found in UTIs in older women. Rare bacterial causes of UTIs include ureaplasma urealyticum and Mycoplasma hominis , which are generally harmless organisms. Organisms in Severe or Complicated Infections The bacteria that cause kidney infections ( pyelonephritis ) are generally the same bacteria that cause cystitis. There is some evidence, however, the E. coli strains in pyelonephritis are more virulent (able to spread and cause illness). Complicated UTIs that are related to physical or structural conditions are apt to be caused by a wider range of organism. E. coli is still the most common organism, but others include Klebsiella , P. mirabilis , and Citrobacter . Fungal organisms, such as Candida specie s. ( Candida albicans causes the "yeast infections" that also occur in the mouth, digestive tract, and vagina.) Other bacteria associated with complicated or severe infection include Pseudomonas aeruginosa , Enterobacter, and Serratia species, gram-positive organisms (including Enterococcus species), and S. saprophyticus .

      bacterial causes

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    1. β-lactams inhibit bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs). This inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) in the absence of cell wall assembly.[9] Due to the mechanism of their attack on bacterial cell wall synthesis, β-lactams are considered to be bactericidal.

      mechanism of action

    1. implicated occasionally as a human pathogen, it is most frequently recovered from nonhuman sources, including aquatic reservoirs (marine, freshwater, and sewage), natural energy reserves (oil and gas), soil, and fish, poultry, dairy, and beef products

      reservoirs

    1. extracellular pathogens such as members of the Attaching and Effacing (A/E) pathogen group that include enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli O157:H7 (EHEC), and Citrobacter rodentium, inhibit innate immune responses while maintaining intimate contact with the host plasma membrane

      immune evasion

    1. A second cardinal virulence factor of E. coli O157:H7 is Shiga toxin, which causes bloody diarrhea and hemolytic uremic syndrome (HUS), a sequelae of EHEC infection. E. coli O157:H7 produces Stx-2, an A-B toxin comprised of a single A subunit noncovalently associated with a pentamer of B subunits. The B subunits bind specifically to globotrioacyl ceramide on host cell cytosolic membranes and facilitates A-subunit uptake by endocytosis. Stx is an N-glycosidase that targets the 28S rRNA, which it depurinates at a specific adenine residue, causing protein synthesis to cease and infected cells to die from apoptosis

      virulence

    2. four distinct systems for acid tolerance. There are four corresponding acid resistance (AR) gene systems. The mechanism of AR1 is unknown. AR2, AR3, and AR4 each depend upon amino acid decarboxylation and consequent consumption of protons, whcih results in pH homeostasis. Expression of the AR systems is induced by acid environment, anaerobiosis, entry into stationary phase. Collectively, one or more of these systems is likely to be "on" when EHEC is exposed to acid, as would be expected to occur upon consumption by a potential host and subsequent passage through the stomach

      virulence

    3. EHEC virulence factors include the ability to adhere tightly to plant materials, acid tolerance, attachment and effacement of intestinal epithelium, and production of endotoxin and Shiga toxin. The regulator of "hyper-adherence", TdcR, and OmpA, an outer membrane protein that is expressed during hyper-adherence are implicated in binding of EHEC to alfalfa sprouts and seed coats. Loss of these virulence factors results in decreased adherence.

      virulence

    1. Bovine manure can harbor viable EHEC for more than seven weeks (Wang et al., 1996), and the long-term environmental persistence of EHEC poses an increased risk for transmission of EHEC through the fecal-oral route through wash-off to nearby farms or in contaminated grass consumed by other cattle.

      public health concern

    2. humans acquire EHEC by consuming contaminated bovine-derived products such as meat, milk, and dairy products (Armstrong et al., 1996) or contaminated water, unpasteurized apple drinks, and vegetables (Cody et al., 1999; Hilborn et al., 1999; Olsen et al., 2002). Direct contact with ruminants at petting zoos or through interactions with infected people within families, daycare centers, and healthcare institutes represent another source of EHEC transmission

      transmission

    3. Antibiotics promote Shiga toxin production by enhancing the replication and expression of stx genes that are encoded within a chromosomally integrated lambdoid prophage genome. Stx induction also promotes phage-mediated lysis of the EHEC cell envelope, allowing for the release and dissemination of Shiga toxin into the environment

      Antibiotics --> increased Shiga toxin production

  3. Apr 2017
    1. TABLE III. MicrobiologyAerobicGram-positive cocciStaphylococcus aureus27MRSA3Coagulase-negative Staphylococcus40 (incl S epidermidis, S hemolyticus)StreptococcusBeta-hemolytic70Group A40Group B17 (incl S agalactiae, 1)Group D6 (non-Enterococcus)Group F5Group G2Alpha-hemolytic/S viridans31

      Table of prevalence of S. aureus, Group A strep, Group B strep, and S. viridans

    1. methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and amoxicillin-resistant enterococci

      Main uses of Vancomycin = bacterias with resistance to other antibiotics, perhaps not usual first line of defense if organism isn't known

    1. develop into a serious soft tissue infection, and can also be complicated by abscesses, septic arthritis and osteomyelitis. Pasteurella spp can also cause meningitis, ocular infections, and respiratory infections, usually in patients with underlying pulmonary disease.

      What are the pt's signs and symptoms? Obvious skin differences near location of bite/scratch? Difficulty moving near injury? Neck pain? Difficulty breathing?

    1. respiratory tract and cause sinusitis and ear infections, and more severe symptoms including pneumonia or lung abscesses in those with underlying pulmonary disease, however this is rare. Other uncommon presentations of P. multocida infection include septicaemia (blood poisoning), eye infections, meningitis and gastrointestinal problems

      Serious complications spread to signs and symptoms in the respiratory tract, blood, meninges, etc.

    2. Exposure to aerosols, bites or scratches involving animals or injuries from objects contaminated with body fluids from animals require immediate first aid and medical attention

      Less likely, but infection can also occur from contact with infected animal bodily fluid, such as contact with infected object