BUGNOTES.pdf - Bacteria of Clinical Importance PDF

Select Bacteria of Clinical Importance most not al Gram (+) and gram (-) bacteria havegea certain type of cell wall called a peptidoglycan cell wall (PG cell wall). A lot of antibiotics work only against those bacteria that have...

Select Bacteria of Clinical Importance most not al Gram (+) and gram (-) bacteria havegea certain type of cell wall called a peptidoglycan cell wall (PG cell wall). A lot of antibiotics work only against those bacteria that have a PG cell wall (e.g., β-lactam antibiotics). Atypical bacteria (with the exception of Legionella) do not have a PG cell wall and Rikemycoplasma thus β-lactam antibiotics will not work against these types of bacteria. so... Blactam xitypical bacterias like mycoplasma as freydort have ↳ who is theexception a Po cellvace Legionella !!!! GRAM (+) BACILLI ?? Listeria immunocompromised - Causes “listerosis” in newborns & adults with a weakened immune system, and the elderly↑ betweenskandaatisse especially organism Swelling of brain gets response Septicemia organism into bloudreis way has made its = big sucha im - Primarily manifests as[ meningitis or sepsis 3 - into blood failure failure it can lead to renal organ - Food-borne: Boar’s Head deli meats, cantaloupe, Blue Bell Ice Cream, spinach, are among the many other sporadic cases of Listeria- contaminated foods that have been detected in the past - Listeria is important in pregnancy. It does not affect the mother but about 20% of infected neonates die. ↓ Mom But 20 % neonates dieA - When pregnant the doctor may tell the mother not to eat certain things. Pregnant women may want to avoid: they're likely to carry this organism as more o Soft cheeses: feta cheese, Camembert, brie, blue vein cheese, queso fresco. * especially way about meningitis in o Deli meats newborn o Hot dogs Bacillus rbioweapon - Of the 34 species of the genus Bacillus, the two of greatest medical importance are B. anthracis, the causative agent of anthrax, and B. cereus, which causes food poisoning. u B. cereus:[ 3Produces toxin that causes N/V/D and Foodborne. abdominal cramps of 24 hr. duration Cerey NIV/D2Uhr duration period Nocardia mainly in immunocompromised pt ; looks like fungus (halffungus half bacterial a - Forms partially beaded branching filaments (acting as fungi, but being truly bacteria) ACT FunG I BUT ESSENTIALy BALike hyphen foot tree = ; of roots in NoCardia that - Causes “nocardiosis,” an opportunistic infection of the enter Skin + cause irritation. immunocompromised. Presents as a slowly-progressing pneumonia. Also my cause infectious endocarditis. In about 2( 25-30% of infected 2  · T) - people it will take the form of[ 3[ encephalitis or brain abscess. 3 In pts with brain infection mortality is about 80%; in other forms mortality is 50% even with appropriate therapy. The usual mode of transmission is inhalation of organisms in dust. Clostridium perfringens DOC Clindamycin +Pend : ↳ - Anaerobe allclost ancebes are - Associated with deep penetrating wounds: gunshot and puncture Attend to bepolymicrobial wounds, surgery, diabetic foot ulcer, bone fractures, septic abortion - Organism feasts on the carbohydrates of muscle, destroying the muscle cells and producing gas by fermentation of muscle carbohydrates → “gas gangrene” destroys carbohydrates of feeds/terments muscle tissue and on the the muscle tissue - Produces toxin that is associated with necrotizing soft tissue infections DOC: Vanco + Fidaximixin Clostridium difficile (recently reclassified as “Clostridioides difficile”) I * - Anaerobe Mom died BSwipe Opportunistic but Cditt out normal Hora and takes overonce it is BS ABX Main Important- * Opportunistic * eurdin that ABX portral , billing Oral , che excretion- opportunity has the. Pat A - Oral antibiotics or parental antibiotics excreted in the bile can cause. the normal flora of the intestines to be suppressed. C. difficile can then proliferate and it releases a toxin that damages the intestinal wall → yellow plaques coalesce in the intestine to form a “membrane” thus - this condition is known as pseudomembranous colitis →diarrhea ( C. - difficile is responsible for 20% of antibiotic-induced diarrheas) - Few drugs cover this organism. DOC is vancomycin, fidaxomicin, or metronidazole Actinomyces – Mouth (oral) anaerobe DOC High Doze : IV Penc - Actinobacteria are normally present in the gums and are the most common cause of infection in dental procedures and oral abscess - - Can cause[ abscesses 3in the mouth, lung or GI tract wall off organism- Actinomycosis is a rare infectious bacterial disease caused by to protect tissuesfrom other Actinomyces species that infect the face and neck → conventional organism therapy for actinomycosis is high-dose intravenous penicillin G Any ABXthat's -.They all are gram-positive and facultatively anaerobic, growing best effective against absees has to under anaerobic conditions. Actinomyces species may penetrate that form endospores, and while individual bacteria are rod- abscess wall. shaped, Actinomyces colonies form fungus-like branched networks of hyphae. The aspect of these colonies initially led to the incorrect E assumption that the organism was a fungus and to the basketball not of hyphae but individually rodshaped  name Actinomyces, "ray fungus" (from Greek actis, ray or beam, and mykes, fungus). yue 10tthe ray like extensions insidethe endospores. - About 70% of infections are due to either Actinomyces israelii or Actinomyces. gerencseriae. - The majority of infections result from Actinomyces spp. colonizing the hosts own oral or respiratory cavities. It is presumed that Actinomyces can be transmitted from person-to-person via direct contact as part of the ↳ Kissing normal oral flora Priopionobacterium Aches Cutibacterium acnes (formerly/more commonly known as acce Propionibacterium acnes) DOC:?? Justthat it fight gram (t) bacilli can Y - Anaerobe produces - Present mainly on the skin: can be found in hair follicles propious acid - Causes acne - When you treat acne you want an agent that fights gram-positive anaerobic bacilli. DOC: Vano Corynebacterium spp. (pronunciation: cory-nay-bacterium) - Coryneform means "club.” In a typical Gram stain these bacteria appear as V-in Y-shaped arrangements or in clumps that resemble u Chinese letters. individual n-shaped together , - We are all vaccinated against Corynebacterium diphtheriae so diphtheria is no longer common - Non-diphtheroid species of this bacteria are found everywhere in/on the body (i.e., [ mucosa and normal skin flora) J - Corynebacterial endocarditis may be seen in patients with intravascular devices - Corynebacterium jeikeium is a multidrug-resistant gram-positive bacterium of the human skin MDR ofhuman Skin (t) - C. jeikeium infection has also been reported in the setting of endocarditis, septicemia, meningitis, pneumonia, and soft tissue infections. Management of disseminated C. jeikeium infection in I immunocompromised cancer patients can be challenging due to its - just like cardia no high virulence and rapid skin colonization. - Corynebacterium is problematic in bone marrow transplant patients since they are immunocompromised (DOC is vancomycin)  GRAM (+) COCCI Staphylococci spp. : FYI (quiz/exam material for Staphylcocci spp. begins at Staphylococcus aureus) Many people carry staph bacteria and never develop staph infections. However, if one does develop a staph infection, there's a good chance that it's from bacteria they've been carrying around for some time. These bacteria can also be transmitted from person to person. Because staph bacteria are so hardy, they can live on objects such as pillowcases or towels long enough to transfer to the next person who touches them. Staph bacteria are able to survive: Drying Extremes of temperature Stomach acid Staph infections can range from minor skin problems to endocarditis, a life-threatening infection of the inner lining of the heart (endocardium). Because of this, signs and symptoms of staph infections vary widely, depending on the location and severity of the infection. Skin infections Skin infections caused by staph bacteria include: Boils. The most common type of staph infection is the boil, a pocket of pus that develops in a hair follicle or oil gland. The skin over the infected area usually becomes red and swollen. If a boil breaks open, it will probably drain pus. Boils occur most often under the arms or around the groin or buttocks.  A carbuncle is a cluster of boils — painful, pus-filled bumps — that form a connected area of infection under the skin Impetigo. This contagious, often painful rash can be caused by staph bacteria. Impetigo usually features large blisters that may ooze fluid and develop a honey-colored crust. S carred Cellulitis. Cellulitis — an infection of the deeper layers of skin — causes Mainly by Sacres + skin redness and swelling on the surface of the skin. Sores or areas of oozing discharge may develop, too. Step-pyogeny Staphylococcal scalded skin syndrome. Toxins produced as a result of a staph infection may lead to staphylococcal scalded skin syndrome. Affecting mostly babies and children, this condition features a fever, a rash and sometimes blisters. When the blisters break, the top layer of skin comes off — leaving a red, raw surface that looks like a burn Food poisoning Staph bacteria are one of the most common causes of food poisoning. Symptoms come on quickly, usually within hours of eating a contaminated food. Symptoms usually disappear quickly, too, often lasting just half a day. A staph infection in food usually doesn't cause a fever. Signs and symptoms to be expected with this type of staph infection include: Nausea and vomiting Diarrhea Dehydration Low blood pressure Bacteremia: Also known as a bloodstream infection, bacteremia occurs when staph bacteria enter a person's bloodstream. A fever and low blood pressure are signs of bacteremia. The bacteria can travel to locations deep within the body, to produce infections affecting: Internal organs, such as the brain, heart or lungs Bones and muscles Surgically implanted devices, such as artificial joints or cardiac pacemakers  Toxic shock syndrome This life-threatening condition results from toxins produced by some strains of staph bacteria and has been linked to certain types of tampons, skin wounds and surgery. It usually develops suddenly with: A high fever Nausea and vomiting A rash on the palms and soles that resembles a sunburn Confusion Muscle aches Diarrhea Stomach pain Septic arthritis: Septic arthritis is often caused by a staph infection. The bacteria often target the knees, shoulders, hips, and fingers or toes. Signs and symptoms may include: Joint swelling Severe pain in the affected joint Fever Staphylococcus aureus colonies look GOLD #1 cause of skin infections * - Found mainly on the skin! Appearance: clusters - Sometimes found in the nose (so occasionally can cause respiratory infections) Blactam ring open and cleave recleare ABX. - 90% of Staph. aureus elaborates a beta lactamase known as penicillinase. Penicillinase cleaves and inactivate PCNs (but NOT other classes of beta-lactam antibiotics). Methicillin was the prototype agent from a class of PCNs that were penicillinase- resistant (MSSA) but now 50-60% of Staph. aureus is methicillin- resistant Staph. aureus (MRSA).  - #1 cause of endocarditis (including that which may arise from IV drug abuse) - #1 cause of toxic shock syndrome - For hospital-acquired MRSA infections DOC is Vancomycin But if it is community-acquired vancomycin is usually held back and other agents like SMZ/TMP, doxycycline, clindamycin are used instead - - Staph. aureus is Coagulase (+) - No beta-lactam antibiotic covers MRSA or MRSE except for the 5th generation cephalosporin,Aceftaroline.* Cepia l Ceftas - VISA → vancomycin intermediate resistant Staph aureus - VRSA → vancomycin resistant Staph aureus Staph. epidermitis - Coagulase-negative staphylococci (CoNS) commonly live on a person's skin. Doctors typically consider CoNS bacteria harmless when it remains outside the body. However, the bacteria can cause infections when present in large amounts, or when present in the bloodstream. Staph. epidermidis is the most important coagulase- negative staphylococcus (CNS) species and is the major cause of infections associated with prosthetic devices and catheters. - Found everywhere on/in the body - Staph. epidermis is not very virulent, so a lot of times it is nothing more than a contaminant when evaluating test results - Infection is seen in immunocompromised pts., those with intravascular catheters or indwelling prosthetic devices (urinary catheters, vascular access devices, endotracheal tubes, tracheostomies, enteral feeding tubes and wound drains) - 70% of Staph. epidermitis is now MRSE (methicillin-resistant) Staph. saprophyticus Dog]UT - #2 causative organism for UTI infections. E.coli is #1 for UTIs. - Coagulase negative (CoNS) Strep. pneumoniae (“pneumococcus”) - Alpha hemolyticepartial - Appearance: cells are found in pairs (i.e., diplococci) - # 1 cause of bacterial L respiratory infections (60-70% of all bacterial pneumonias) # on CAP botitis mastriditis , , - # 1 cause of meningitis y who esse cases meningiors ? Listric also causes Septic shock.  - Penicillin-resistant strains are becoming more and more common - If moderate resistance to PCNs, use ceftriaxone +/- vanco; or a “respiratory” fluoroquinolone (FQ) in Strep. pyogenes (Group A, β-hemolytic Steptococcus) chain diplo presen - Culture on blood agar. Organisms that are beta hemolytic produce a clear zone - Appearance: cells linked in a chain - Strep. pyogens is a major type of beta hemolytic gram (+) cocci. - Causes strep throat (pharyngitis) and rheumatic fever. It has I some antigens heart resemble the bactria and imm Syst attacks the values and cacies the rherm-fever. antigens which you form an immune response to. Antigens on heart on. are similar, so if the organism reaches the blood, the immune response to S. pyogenes can cause an immune response to the heart causing rheumatic fever (= carditis with possible extensive valve damage) - Staph. aureus and Strep. pyogenes are the most common causative organisms of skin and soft tissue infections (e.g., cellulitis) ① St Aurere. - #2 cause toxic shock syndrome ⑧ Strep Ryo. - Dangerous strains have produced necrotizing fasciitis (“flesh-eating bacteria”) Strept. agalactiae DOC Amp : - 1/3 of women are vaginally or rectally colonized with this bacteria - #1 cause of septicemia and meningitis in newborns. picks e it up in Sirtucanal - Test for this organism in pregnancy and if positive prophylax with IV ampicillin 24 hours before expected delivery Neonates Listeria Agalattice : ,. Viridans group streptococci (S. anginosus, S. constellatus, S. gordonii, S. CDOC : Amox( intermedius, S. mitis, S. mutans, S. oralis, S. parasanguinis, S. salivarius, S. sanguinis, and S. I Major cause tooth caries uberi) of - Produce a green discoloration on blood agar hence the term “viridans” (Latin for green) - Have the unique ability to synthesize dextrans from glucose which allows them to adhere to fibrin-platelet aggregates on damaged heart valves: - During dental procedures these bacteria can enter the bloodstream and travel to your heart causing endocarditis > - - These organisms are most abundant in the mouth: Tiridans grop step.  S. mutans for example is found in the mouth b/w your teeth and is a major cause of tooth caries - If you have heart problems, before you go to the dentist they will prophylax you (e.g. amoxicillin) so you’re protected. - Also can cause meningitis, tooth abscess, bacteremia, abdominal infection Enterococcus faecalis and Enterococcus faecium - NOT very pathogenic, and typically cause infections in patients after broad-spectrum antibiotic use ec diff too ! ". - 90% of all enterococcus is Enterococcus faecalis (most abundant enterococci). nd r vet umm You've E... - 2 most abundant is Enterococcus faecium more resistant - Enterococci are a type of bacteria that live in the GI tract. There are at least 18 different species of these bacteria. These bacteria also live in the mouth and vagina. - They are very resilient, so they can survive in hot, salty, or acidic environments - E. faecalis infections spread from person to person through poor hygiene. Because these bacteria are found in feces, people can transmit the infection if they don’t wash their hands after using the bathroom. The bacteria can get into food or onto surfaces such as doorknobs, telephones, and computer keyboards. From there, they can pass to other people. - E faecalis doesn’t usually cause problems in healthy people. But people with underlying health conditions or a weakened immune system are more likely to get sick E faecalis mostly infectimmunocompromised - E. faecalis can get into the blood, urine, or a wound during surgery. From there, it can spread to different sites causing more serious infections, including sepsis, endocarditis, and meningitis. - These organisms can cause UTI,Ebacterial endocarditis, 3 bacteremia, diverticulitis, and meningitis Enterococcus - High level of intrinsic antibiotic resistance St Ave Tevin Stree. - Beta-lactam antibiotics are only static against this organism - DOC is amoxicillin (UTI) or ampicillin (other types of infxns) - Bug can become resistant to amoxicillin or ampicillin. - It used to be uniformly susceptible to Vancomycin. In the last 25 years VRE has emerged (vancomycin resistant enterococcus) - If someone has enterococcal endocarditis they may be on IV antibiotics for a month.  - When someone has a VRE infection most of the time the organism responsible for this will be Enterococcus faecium (i.e., the less common of the two major Enterococci species) Peptococcus/Peptostreptococcus More common mouth anglobes – Gram positive mouth (oral) anaerobes GRAM (-) BACILLI Listen to e 1 : 24 ↳ most occur imm Comp in. Mnemonic→ SSSH KeeP the PPEACE” or thouse wh long hardware or urinary cathete or prosthetic device. Note: Most of the following gram negative rods are classified as members of the “Enterobacteriaceae” EXCEPT for: It A4 * D Haemophilus, Acinetobacter, and Pseudomonas (you MUST remember these 3 exceptions). S→Serratia marcescens.Oneof theSPACE-Morganism. - Produces characteristic red pigment. - S. marcescens is commonly found growing in bathrooms (especially on tile grout, shower corners, toilet water lines, and basins), where it manifests as a pink, pink-orange, or orange discoloration and slimy film feeding off phosphorus-containing materials or fatty substances such as soap and shampoo residue - Commonly found in the respiratory and urinary tracts of hospitalized patients. Involved in nosicomial infections: catheter-associated bacteremia, UTI, and wound infections NOSOCOMIAL - S→Salmonella spp. – S. typhi causes typhoid fever; S. enteritidis causes gastroenteritis (diarrhea, fever, vomiting, and abdominal cramps). · Symptoms usually begin 6 hours to 6 days after infection and last 4 to 7 days. Most common reported cause of food-borne illness in the USA - S→Shigella spp.- produces a toxin that causes dysentery. Shigella infection (shigellosis) is an intestinal infection. The main sign of shigella infection is diarrhea, which often is bloody. Shigella is very contagious.  Ost pheu & - Haem Her. - H→Haemophilus influenzae (“H. Flu”): #2 cause of community- acquired bacterial respiratory infections list. Not classified as an “enterobacteriaceae”. In infants and children it may cause bacteremia, pneumonia, and acute meningitis AtXresistant Stop 10 Most - K→Klebsiella spp.: Some species are easy to treat and some are multidrug resistant: Increasingly, Klebsiella pneumoniae bacteria are exhibiting antimicrobial resistance, most recently to the ~ carbapenem class of antibiotics ↳ Yance of gran - The most common cause of nosocomial respiratory infections. (t) Produces a bloody sputum (looks like red currant jelly). - 2nd most common cause of gram negative bacteremia and UTI. - Alcoholics are more susceptible to getting Klebsiella infections (pneumonia) than the general population. - Sometimes causes soft-tissue infections. - In humans, the bacteria are often present in parts of the digestive tract where they do not generally cause problems. - In the USA, Klebsiella pneumoniae and Klebsiella oxytoca are the two Klebsiella species responsible for most human illnesses - Klebsiella aerogenes was formerly known as Enterobacter aerogenes and has been recently reclassified as a Klebsiella species. It is one of the “ECK” organisms with a moderate-to-high risk for inducing the AmpC beta-lactamase - P→Proteus spp. : o P. mirabilis and so-called “Indole (+) Proteus spp.” [u + B o Colonies form “swirls” flagella moves outward > - o P. mirabilis causes UTI and wound infections. Causes more kidney infections than E.coli o So- called “Indole positive proteus” includes Proteus vulgaris, Morganella morganii and Providencia rettgeri o Indole (+) Proteus usually only target immunocompromised patients. Mainly causes UTI o Morganella morganni is not technically a Proteus specie, but at one time was identified as such. Falls under the category of indole-positive Proteus. - "M" in SPACE o All Proteus species can break down urea to form ammonia. The pH of the urine therefore goes up (i.e., more alkaline). About 10- Causes more kidney infections than UTI  15% of kidney stones result from this action. The urinary tract antiseptic, methenamine, needs an acidic urine to work and therefore Proteus species will be intrinsically resistant to the urinary tract antiseptic methenamine (which requires an acidic pH to be activated PRODROG needs an asidic medium for Protees - o Produce hydrogen sulfide as part of their metabolism → stink Providencia spp. (FYI) - The genus Providencia includes urease-producing gram-negative bacilli that are responsible for a wide range of human infections. - Although most Providencia infections involve the urinary tract, they are also associated with gastroenteritis and bacteremia. P stuartii septicemia is primarily of urinary origin. - Providencia infections are uncommon and are usually nosocomial - Providencia stuartii and Providencia rettgeri are the most common infectious species of Providencia. - In humans, Providencia species have been isolated from urine (most common), stool, and blood, as well as from sputum, skin, and wound cultures.- P stuartii is frequently isolated in patients with indwelling urinary S catheters and is known to persist in the urinary tract after bladder access is attained SQACEN - The persistence of bacteria in the urinary tract is thought to be due to an adhesion molecule which allows bacteria to adhere to urinary catheters - P→Pseudomonas aeruginosa (very! Important organism to remember) o Has slime coat and a flagella thrives in moisture bot slime coat o Thrives in moisture. porindeficient o Can cause green discoloration at infected sites pseudomonal o Has a characteristic “fruity” odor (grapes?) infections o Most frequent colonizer of medical devices (e.g., catheters, ventilators) o Most often affects the immunocompromised, debilitated, and those with damaged tissues  o A particularly hard-to-treat nosocomial organism. (One in ten hospital-acquired infections are due to this organism) o Most common cause of burn infections, and those of the outer ear (otitis externa) o Typically infects the pulmonary tract (pneumonia), urinary tract, burns, wounds, and causes sepsis o Cystic fibrosis patients are predisposed to infections of the lungs o Common cause of infection in radial keratotomy surgery patients o Can cause osteomyelitis in puncture wounds of the foot ↳ LASIX (inoculation from tennis shoes) o High intrinsic antibiotic resistance due to deficiency of permeable porins on its envelope, efflux pumps which pump out antibiotics, and/or production of beta-lactamases LSLIME MAKES IT o Major problem is that is can become multi-drug resistant O SPACE-Morganism E→ E.Coli: #1 cause of UTIs. approx. 80% of all UTIs. - Virulent strains can cause gastroenteritis and neonatal meningitis. - Enterotoxigenic E. coli are the leading cause of diarrhea in developing countries and the most common organisms involved in “traveler’s diarrhea”. Hagen - Enterohemorrhagic E.coli O57:H7 (usually foodborne) strains cause a severe bloody diarrhea and hemorrhagic colitis. In about 2-7% of patients the colitis progresses to hemolytic uremic syndrome (HUS) which causes destruction of red blood cells and renal failure. Children who are less than 5 years old, people with weakened immune systems (such as those with cancer, HIV/AIDS, or a transplant) are more at risk to develop the disease. A→Acinetobacter baumannii: Infections seen in the hospital, typically in ICU unit. - Can cause life-threatening infections in the immuno- ↓ pseud arreginosa a like. compromised A frequent cause of nosicomial pneumonia - Associated with pts. with lung hardware (causes late–onset ventilator-associated pneumonia). - Also causes skin and wound infections and bacteremia - Can survive for weeks on the skin and dry surfaces. - Some strains have been known to acquire up to 45 resistance genes thus it sometimes is super multidrug-resistant.  -Colistin (polymyxin) can be used for MDR forms of this bug but it is nephrotoxic (and somewhat neurotoxic: paresthesia). - Like Psuedomonas auerginosa, it is a non-fermenter (can’t covert lactose to acid) fore pH to assees -NOT classified as an “Enterobacteriaceae” - ONE OF SPACE MBACTERIA - C→ Citrobacter freundii: Found in the intestine. Rarely the source of infection. When infections do occur it usually presents as UTI, infant meningitis, or septicemia. One of the “ECK” organisms SPACE-W e and entrobacte aerogenes - E→Enterobacter cloacae. One of the “ECK” organisms. Causes opportunistic infections in the immunocompromised (usually hospitalized) and patients on mechanical ventilators. Most common sites of infection are the respiratory and urinary tract. It is also a fecal coliform like E. coli ( Do not confuse Enterobacter with the 4c gram positive organism, Enterococcus !!) SPACEM Y(+ ) “ SPACE-M” These aerobic bacteria potentially harbor the inducible Echromosomal3Amp-C beta lactamase gene. Trend has been to avoid it using 3rd generation cephalosporins as they can be inducers of this beta- not lactamase (Use of 1st and 2nd generation cephalosporins (or shared it aminopenicillins) is irrelevant b/c they never covered these organisms in anyway): Xyidgen Ceph chromosome Serratia marcescens they as AmpC navethe gee Pseudomonas aeruginosa or Providencia stuartii and is inducible and Acinetobacter baumannii see it go more plasmids over to which bads , then the Citrobacter freundii is gene can se shared Enterobacter cloacae & aerogenes (Enterobacter aerogenes has been renamed as Klebsiella aerogenes) Morganella morganii More recently there has been a re-examination of which organisms are most likely to exhibit inducible chromosomal Amp C production and a new mnemonic has been suggested: “HECK YES” Hafnia alvei Enterobacter cloacae Citrobacter freundii  Klebsiella aerogenes (formerly known as Enterobacter aerogenes) YErSinia enterocolitica Hafnia alvei and Yersinia enterocolitica infxns are uncommon and not routinely reported as part of clinical laboratory findings, so raw data is scarce. The focus therefore has been on the other three bacteria, “ECK” on this list Stenotrophomonas maltophilia same class pseudomonas > - a - An aerobic, nonfermentative, gram-negative bacterium. It is an uncommon bacterium and human infection is difficult to treat - Frequently colonizes humid surfaces such as the tubes used in mechanical ventilation and indwelling urinary catheters as well as medical devices such as suction catheters and endoscopes. - Infection is usually facilitated by the presence of prosthetic material (plastic or metal), and the most effective treatment is removal of the prosthetic material (usually a central venous catheter or similar device). - In immunocompetent individuals, S. maltophilia is a relatively rare cause of pneumonia, urinary tract infection, and bloodstream infections; in immunocompromised patients, however, S. maltophilia is a growing source of latent pulmonary infections. - May be resistant to many broad-spectrum β-lactams including carbapenems due to the production of two metallo- beta lactamases. Not covered by many of the antibiotic classes (SMZ/TMP is DOC). t really effective ANAEROBIC Gram negative bacilli "angeobic gramlt rod" in activating It a drug cover B. frag we consider it an excellent cover against anaerobes Blactamase ** Bacteriodes fragilis (“B-frag”) – a “tougher” anaerobe to treat - One of the gram (-) anaerobes. Makes up the most substantial part of the normal gastrointestinal flora preformation gets > - bad when there's when it outside of the normal pot. - Pathogenicity partly results from its ability to produce capsular polysaccharide, which is protective against phagocytosis and stimulates abscess formation. - Dominant anaerobe in the abdomen. Need to cover in abdominal infections and so-called “dirty” surgery” - Opportunistic. Causes infections of the peritoneal and pelvic cavities (caution: gastrointestinal surgery e.g., colorectal, hysterectomy, appendectomy via abscess formation and inhibiting phagocytosis  Prevotella spp. (FYI) - Prevotella spp. are members of the oral, vaginal, and gut microbiota and are often recovered from anaerobic infections of the respiratory tract. These infections include aspiration pneumonia, lung abscess, pulmonary empyema, and chronic otitis media and sinusitis - Prevotella melaninogenicus produces a black pigment when grown on blood agar, hence the name melaninogenicus. Lives in the mouth, vagina, and intestine, and is usually involved in necrotizing anaerobic pneumonias caused by aspiration of lots of sputum from the mouth (during a seizure or drunken state). It also causes periodontal disease. Fusobacterium (FYI) - This anaerobic bacterium is just like Prevotella melaninogenicus in that it also causes periodontal disease and aspiration pneumonia. Fusobacterium can also cause abdominal and pelvic abscesses and otitis media. Miscellaneous gram negative bacilli: Yersinia enterocolitica: An enteric organism causes enterocolitis. (Infection with Yersinia is often linked to eating raw or undercooked pork) Yersinia pestis→ causes bubonic plague ( a NON-enteric organism) carried "pestis" > - on rats Bordetella pertussis →causes “whooping cough” ↓ particularly bites cat Pasteurella multocida→ bacteria associated with animal bites (cat /dog) Campylobacter jejuni→ Foodborne; causes traveler’s diarrhea Brucella: Brucellosis in humans is usually associated with consumption of unpasteurized milk and soft cheeses made from the milk of infected animals—often goats—infected with Brucella melitensis, and with occupational exposure of laboratory workers, veterinarians, and slaughterhouse workers. In the past brucellosis was known as the “butcher’s disease” "Broce slaughte works at the houseand drinks raw milk" Burkholderia: these species were initially classified as part of the Pseudomonas genus. The most import specie is Burkholderia cepacia an important pathogen of pulmonary infections in people with cystic fibrosis3 [ I likeul arreginosa  Pen6 crosses BBB When meninges we inflamed GRAM (-) COCCI Neisseria gonorrhoeae (“gonococci”)→causes gonorrhea. Ceftriaxone + azithromycin is a treatment of choice Pend DO Neisseria meningitidis (“meningococci”)→ Causes a rapidly-progressing deadly meningitis all done contact need prophylaxis ; deadly rapidly progressing Moraxella catarrhalis (“M.cat”) #3 cause of community-acquired respiratory infections meow coughing (cat Cough meow is #3 CA respiratory infections M. Cat be its in MCAT ① Strep pres- ② Haempholius Influ List of non-fermenters (FYI: the non-fermenting property is helpful in laboratory identification of these organism) Acinetobacter Bordetella Burkholderia Legionella Moraxella ( a gram negative cocci) Pseudomonas Stenotrophomonas Treponema pallidum (FYI) know Great imitator keeps coming back in different form a - Causes syphilis (“the great imitator”) - Benzathine PenG is the usual drug of choice in those patients without a PCN allergy - It is a micro-aerobic spirochete often described as Gram negative, but its outer membrane (envelope) lacks lipopolysaccharide, which is found in the outer membrane of other Gram-negative bacteria. 1. Primary syphilis: Onset: 2 – 4 weeks after infection Presentation: Ulcer on the genitalia. Ulcer known as hard chancre, firm, clean and circumscribed. Chancre fluid is rich in treponemes. Ulcer heals up spontaneously in 10 – 40 days. 2. Secondary syphilis: Onset: 2 – 8 weeks after primary syphilis.  Presentation: Skin eruptions, red rashes with papules. Widespread multiplication and dissemination in blood. Patient highly infectious. Other symptoms include fever, malaise and general lymphadenopathy. May last from 10 days to 1 year. 3. Tertiary syphilis (early and late latent stages): Early latent stage: This is inactive stage following secondary syphilis. Patient is non-infectious, though fetus of an infected mother can be infected. Late latent stage: Onset is approx. 3 years after secondary stage: Presentation: Inflammatory lesions in any organ or tissue but CNS and cardiovascular systems are mostly involved. Complications may include granuloma of skin or bone, liver damage, eye impairment and ear dysfunction. Patient is non-infectious except to the fetus of an infected mother ATYPICAL BACTERIA: Atypical bacteria are bacteria that do not get colored by gram-staining but rather remain colorless: they are neither Gram-positive nor Gram-negative (exception is Legionella). They are often hard to detect in the laboratory b/c they can hide intracellularly. Atypical bacteria include the Chlamydiaceae, Legionella , and the Mycoplasmataceae (Mycoplasma and Ureaplasma). The Rickettsiaceae are also often considered atypical. tend to hide IC and don't stain very were Mycoplasma pneumoniae: causes “walking pneumonia” (aka “atypical pneumonia”); mycoplasmas do NOT have a cell wall. Hard to identify in lab tests because it grows very slowly (complicates antibiotic selection) Legionella pneumonoplia: L. pneumophila is a facultative intracellular parasite. While L. pneumophila is categorized as a gram-negative organism, it stains poorly due to its unique lipopolysaccharide content in the outer leaflet of the outer cell membrane. Behaves as an atypical because it hides intracellularly: In the natural environment, Legionella lives within amoebae which can serve as a reservoir. Upon inhalation, the bacteria can Stains gramc- but lives IC therefore = Atypical infect alveolar macrophages, and replicate. This results in Legionnaires' disease and the less severe illness Pontiac fever. Legionella transmission is via inhalation of water droplets from a contaminated source that has allowed the organism to grow and spread (e.g., cooling towers). Legionnaires meeting ; breathing hotel 34 people died inside the. it Chlamydophila pneumoniae - causes pneumonia; hides intracellularly -psipsit bird the pneumonic Chlamydophila psittaci - respiratory infxn (“psittacosis”) may be contracted from the feathers of exotic birds such as parrots Starts out as flu-like symptoms, developing into a life-threatening pneumonia Chlamydia trachomatis - Chlamydia trachomatis is actually a gram-negative bacterium but is classified as an “atypical” b/c it can replicate only within a host cell - The #1 sexually transmitted disease in the USA: causes “nongonococcal urethritis” (“NGU”). Ureaplasma urealyticium also causes NGU. - Causes “trachoma” the #1 cause of preventable blindness in the world. Gets under the eyelid and causes scar tissue that scratches cornea and causes blindness MYCOBACTERIA > - need 2-3 ABX 4TB Have a special cell wall largely made up of mycolic acids (waxy). Mycobacterium tuberculosis and Mycobacterium leprae (leprosy), and MAC (see below) are examples Mycobacterium avium complex (MAC): MAC infection is a serious condition that can cause damage to the lungs. Some cancers and anything else that weakens the immune system can makes individuals more vulnerable. HIV patients get MAC infections. It is not contagious  PROTOZOA Toxoplasma gondii toxoplasmosis - Infection usually occurs by eating undercooked contaminated meat, exposure from infected cat feces, or mother-to-child transmission during pregnancy. Stay away from kitty litte - Pregnant women around kitty litter need to be cautious of this protozoan. Attacks the fetal brain. Causes miscarriages and stillborn babies. In infants who survive, there can be seizures, an enlarged liver and spleen, jaundice, severe eye infections - Often, infants who are infected don't develop signs — which may include hearing loss, mental disability or serious eye infections — until their teens or later. - Also HIV patients can get this - FUNGUS ↑ & DOC : Bactrim asked on quizzes classified as a fungus Pneumocystis jerovecii causes pneumonia (PCP) in HIV patients. Propylax! - - jerovichi is a funge Cryptococcus neoformans is a fungus that lives in the environment throughout the world. People can become infected with C. neoformans after breathing in the microscopic fungus (from pigeon droppings for example), Most people who are exposed to the fungus never get sick from it. C. neoformans infections are rare in people who are otherwise healthy; most cases occur in people who have weakened immune systems, particularly those who have advanced HIV/AIDS. 12 jeroveciFans- propl chrefinitis Minimum Inhibitory Concentration (MIC): The lowest concentration of an antibiotic required to inhibit the (visual) growth of an organism When you see an abnormally large MIC value it may indicate the bug is resistant to that antibiotic Static agents→ the bug is not killed but the growth is inhibited and the immune system takes over and kills the bug Cidal agents → kill the bug completely. Often required when treating HIV or other immunocompromised patients FYI COMMON BUGS FOR SELECT INFECTIONS ( #1 cause is underlined) Otitis Media: Streptococcus pneumoniae, Haemophilus, Moraxella Meningitis in Newborn: Streptococcus agalactiae, E. coli, Listeria Meningitis in Infants / children: Streptococcus pneumoniae, Neisseria, Haemophilus influenzae type b Meningitis in Adolescents: Neisseria, Streptococcus pneumoniae Meningitis in Adults: Streptococcus pneumoniae, Neisseria, Haemophilus UTI: E. coli, “PEKEPS” ( Proteus, E.Coli, Klebsiella, Enterococcus, Pseudomonas, Staph saprophyticus) Endocarditis: ( a potentially fatal inflammation of your heart valves' lining and sometimes heart chambers' lining): Staph aureus, Viridans group strep, Enterococcus = ”SaVE” Cellulitis: Staph aureus (MSSA & MRSA), Strep pyogenes. (Diabetic skin infections are polymicrobial: combination of Gram +, Gram -, Anaerobes) Intra-Abdominal Infections (generally post-surgical): B. fragilis, E. coli, Enterococcus, Pseudomonas Cystic Fibrosis: Pseudomonas, Burkholderia, Haemophilus Gastrointestinal Infections (Gastroenteritis): 95% are viral (“stomach flu”); Salmonella, Shigella; Campylobacter; E. coli, Clostridium difficile (history of recent Abx use); Giardia lamblia (a protozoal parasite) _____________________________________________________________________ Empiric therapy: Definition: Treatment before the infecting organism has been positively identified. In one scenario, someone presents with a seemingly uncomplicated infection and the doctor decides that a culture is not warranted Example: A mother brings her child with an ear infection (otitis media) to a doctor or clinic. Otitis media is an example of an upper respiratory infection that is common in children. The organisms that cause the most community-acquired upper respiratory infections (in this example, an ear infection) are Strep. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. In simple cases like this, a culture is not taken; instead an agent that covers all three of these organisms is prescribed (e.g. amoxicillin). In another scenario, a patient presents with a life-threatening type of infection (e.g., septicemia) that absolutely requires immediate treatment. In this more dire scenario (septicemia), a very broad-spectrum antibiotic can be administered while awaiting for the laboratory to definitively identify the causative microorganism(s) “ESKAPE” bacteria are those organisms for which resistance to antibiotic treatment is becoming increasingly prevalent: Enterococcus faecium Staphylococcus aureus MRSA XRSA Klebsiella pneumoniae and Klebsiella aerogenes Acinetobacter baumannii Pseudomonas -Skinne aeruginosa Enterobacter cloacae.