Streptococcus, Gram negative rods, cocci and spirochetes

• Study notes have been generated from the images provided.

Streptococcus agalactiae

• Streptococcus agalactiae is a Lancefield group B, beta-hemolytic bacteria that exhibits complete hemolysis.
• Colonization by Streptococcus agalactiae is asymptomatic in the upper respiratory and genitourinary tracts.
• Neonates are susceptible to the most serious diseases caused by Streptococcus agalactiae.
• Infants can develop bacteremia, pneumonia, or meningitis from the Streptococcus agalactiae bacteria.
• During and after pregnancy, women can contract urinary tract infections.
• Postpartum infections can occur.
• Screening pregnant women for S. agalactiae infection is important to prevent neonatal disease, and treatment is necessary if tested positive.
• Penicillin G is a treatment along with aminoglycosides like streptomycin, gentamicin, or tobramycin for serious infections.
• Vancomycin is an alternative treatment when there is an allergy to Penicillin G.

Streptococcus pneumoniae

• Streptococcus pneumoniae commonly lives in the throat and nasopharynx of healthy people.
• Pneumonia, sinusitis, otitis media, meningitis, and bacteremia can result as the bacteria spreads to the lungs, sinuses, ears, the central nervous system, or blood.
• In the U.S., S. pneumoniae causes about 500,000 pneumonia cases/year.
• About 7 million cases of Sinusitis & otitis media in US ear infections.
• Pneumonia has the highest incidence in children and the elderly, who have a low antibody response to pneumococcal capsule polysaccharides
• It spreads from existing organisms rather than by contagion.
• Pneumonia often follows or occurs in patients with COPD, congestive heart failure, diabetes or renal disease.
• Vaccines for pneumonia include: Adults, which are composed of 23 pneumococcal polysaccharides (PPSV23)
• While Childrens vaccines consist of 13 capsular polysaccharides conjugated with a protein (PCV13)
• Effective antibiotics include beta-lactams and erythromycin, although resistance to penicillin is a growing problem.

Streptococcus anginosus

• One or more prevalent pathogens found in endodontic abscesses (generally polymicrobial)
• Endodontal abcesses can lead to bacteremia, via vessels near teeth.
• Leads to shock and death due to very serious situation.
• Treatment must be diligent and agressive
• Attention should be given to all patients with jaw pain and endodontic problems
• Possible to die from tooth ache
• Learning objectives: to know, staphylococcus, aerius/epidermidis, streptococcus, pyogenes/agalactiae/pneumoniae/angiosus

Bacillus & Clostridium

• Gram-positive rods that are medically relevant and form endospores.
• Bacillus is aerobic/facultative.
• Clostridium is anaerobic, obligate Anerobe so can only go through fermentation.
• Bacillus anthracis causes anthrax.
• Clostridium perfringens, tetani, botulinum, and difficile are examples of bacilli. Clostridium tetani causes tetanus.
• Botulism toxin has medical uses, like treating blepharospasm and wrinkles.

Bacillus anthracis

• Cause for anthrax
• Carries two plasmids: One codes for a poly-D-glutamate capsule resists phagocytosis, and so lasts longer in the body. The other codes for 3 exotoxins like protective antigen, edema factor, lethal factor YTNFQ release.
• Edema toxin: Composed of protective antigen plus edema factor, an adenylate cyclase, which converts ATP to cyclic AMP and in turn is the cause of fluid accumulation in disease
• Lethal toxin: Composed of protective and lethal factor which is a zinc metaloprotenase. Causes TNF-a release.
• Once plasmids are lost the strain becomes avarulent
• Is mainly a disease of ruminants like cattle, sheep and goats and horses.
• Can be found all around the globe.
• People can be infected through direct animal contact with trauma, trauma-induced soil contaminated with spores from animals, or inhalation of spores from dry animal hides and wool
• At risk: veterinarians, cowboys, herders, and those who process animal hides and wool which is very dangerous because soliders and citizens are especially at risk due to bioterrorism and warfare.

Anthrax

• Occurs in three possible types of disease
• Cutaneous is most common type that is spread through trauma from animal or soil.
• Pulmonary is very rare; aka Wool Sorter's Disease found through the inhalation of dried material on animal hides, or by bioterrorism using dry powder containing spores. Does mot spread person to person
• Gastrointestinal is extremely rare found from eating contaminated meat.
• Cutaneous form: 20% mortality untreated, & <1% treated
• Pulmonary form: 100% mortality untreated, & 50-90% treated
• Treatment requires: Ciprofloxacin, Tetracycline (doxycycline), and/or Penicillin G/Amoxicillin.
• Treat cutaneous with one, pulmonary with multiple

Bacillus cereus

• Causes gastrointestinal problems, heat stable enterotixins from cooked growth will cause naseau, vomiting and cramps from food that is stored.
• Heat labile enterotoxins is what causes diarrhea due to ocular infection from penetrating trauma.
• causes Endophthalmitis eye infection in 65 YO Woman
• Requires caratact surgury and intravitreal injeection with vancomycin.
• Can be relevant spore former when doing and autoclave test, its spores are used in kit to test autoclave function but a thermophile, so cannot affect humans.

Clostridium perfringens

• Gas Gangrene
• obligate Aneribe so toxic byproduct of fermentation
• widespread in soil is most serious problem where high numbers are found in faces
• most serious problem results from trauma or surgical wounds, or even cellulitis and faciitis.
• This is due to myonecrosis with gas gangrene, can be polymicrobial so multiple bacteria species are involved
• Trauma and surgery wounds which are “puncture” or deep wounds (penetrating trauma) are most at risk.
• Since tissue infected is deep, there will be less access to air, and and trauma/surgery causes poor blood supply, so it can grow the bacteria
• Blunt trauma wounds (e.g. crushing), causing little wounding on the surface, can cause necrosis, with infection via blood stream, and still result in gas gangrene

Clostridium perfringens (Continued)

• Trauma: surgery wounds which are at most "puncture" or "deep" wounds because of better access for anaerobic growth.
• Occasional problem with "Perfringens food. poisioning" is caused due to enterotoxin, that can have food poisoning coupled with complete cooking or lack a refrigeration.
• Can lead to symptoms of cramps and diarrhea in 8 to 24 hours where you need rehydration, and can get it for water & soup.
• Prevention and treatment options for wound infections, like avoiding trauma, and prophylactic treatment for all wounds is essential

Clostridium tetani

• C. Tetini is ubiquitous in soil but there are other human variants as well
• Tetanus is introduced through puncture of the tetani pores lead to wound growth in the local area of infection.
• The tetanus toxin/tetanospondin is released by old cells within the growth and block neurotransmitters and ultimately contraction some portions of the body.
• This is a major problem because if one portion of the body contracts uncontrollably, it can lead to death from asphxiation.
• Is prevented from: vaccinations and wounds are kept clean all the time and can be cleaned.
• This occurs because the nerve cells have too many toxins
• The Tetanus (Lockjaw) is a clinical disease where: In US, <50 cases/y; ~1 million/y in world but in US old are the most susceptible

Tetanus and Clostridium treatment prevention

• Drooling, Lockjaw, Cardiovascular symptoms occur with mortality rate at around 20-50%
• The Metroidazole can not perform once it is precent: Wound debridement as well. Clostridium botulinum are widespread in the body to bind when a body is irriversibly attacked.
• This is also common in adults and infants too
• Food born botulism: leads to many issues and will need eliminate to keep down the Gl tract
• In infants avoid feeding them honey.

Clostridum botulinum Continued

• Growth in wound, in the adults and infants is rare.
• Treat food with adults. Do not feed infants hunny as this can cause eye twitching because the eyes can not kept open leading to the need for both physician's help.

Clostridium difficile

• Part of intestinal flora in 1 to 3% of population
• Can be transmitted to patient in hospital from adjacent patient (i.e. a nosocomial infection)
• Normally, causes no problem
• But, if patient treated with certain antibiotics that lead to killing of many Gl bacteria (e.g. ampicillin or clindamycin)Overgrowth of C. difficile, more enterotoxin & cytotoxinCauses diarrhea and/or colitis, mild to severe
• CDAD - overgrowth of C. diffgive probiotics to pts being given antibiotics.
• Treatment: Stop initial antibiotic if possible, and replace if neededRehydrate, use probiotics often suggestedTreat with vancomycin or fidaxomicin (Dificid>(Older approach was metronidazole, can use if money is limiting) new option is rifaximin, this both fidaxomicin and rifaximin inhibit RNA polymerase. Unusual macrocyclic antibioticPoorly absorbed, meaning it largely stays in Gl tractTarget of action is RNA polymerase expensive.
• large complex glycopeptide antibiotic that defies classification,Poorly absorbed in Gl tract, meaning oral vancomycin remains in Gl tract,Inhibits cell wall biosynthesis (know mechanism as described earlier) semisynthetic antibiotic of the rifamycin classpoorly absorbed orally, and thus good for some 97% GI infections,Use to treat Clostridium would be used with program,expensive. Frequency and seriousness is always different but always has good newer treatment even newer that using Clostridium This could be far preferable.

Enteric and Gram-Negative Bacteria Overview

• Describe Nesseria, Treponema, and Pseudomonas as Gram-negative cocci, spirochetes and rods, respectively, and Neisseria as often an intracellular diplococcus.
• Describe the diseases, their transmission, prevention and appropriate examples of treatment associated with:- Neisseria (gonorrheae and meningitides)- Treponema pallidum- Pseudomonas aeruginosa and Burkholderia cepaciaDescribe a urinary catheter, when it is used, and potential microbiologicalproblems arising from its use. -Describe environmental sources for and diseases caused by Acinetobacterbaumanniill. Gram Negative Rods [GNR], has - Outer Membrane = YES
• Name the causative agent, route of infection, symptoms, and where appropriate some description of treatmentoptions for typhoid fever, paratyphoid fever, salmonellosis,shigellosis, Yersinia gastroenteritis, and the bubonic plague.

Enteric bacteria info

• Enteric stain pink/red rods all facultative.
• Gram negative, rod-shaped, facultative
• Members of the family Enterobacteriaceae examples)
• Of over 150 enteric species, only 20 cause > 95% of infections.
• All enteric are GNR's but not all GNR's are entericsnot present in gut. changed from Enterobacteriaceae (family) to Enterobacterales (order)when Morganella, Proteus, Providencia, and Serratia.
• GPC in pairs and chains Gram positive rods Precent in Gut! most common normal GL Flora UTI
• In your gut" organism normal GL Flora
• Two main species:1. Very friendly guy2. sounds like "faeces" most. responsible for30-35% of all septicemia70% of Urinary Tract infections
• Gastro-intestinal illnesses of many varieties rare.

Outer Membrane Strain Designations

• H antigen: flagellaO antigen: LPSK-antigen: capsule
• cause lot of infections Thus E. coli 0157-H7 is determined by the specific structure of its flagella and LPS
• released & from Los LPS/endotoxin is an essential part of Gram-negative outer membrane caused shock Activation of innate immune system which producesvasodilation. inflammation, and This can produce vascular shock andresult in death.

Gram Negative - Escherichia coli diseases

• Disease locations in human bodies, and found in animal GI. Bacteria can cause infections when colon is harmed and is from a serious strand of infections.
• Can get bacteremia or sepsis, or urinary infections.
  • Urinary tract infections can from typical infections and cause bad health problems. Also urinary cathader

Escherichia col Gastroenteritis info

• Fecal-oral transmission, direct or indirect through travelers water, where if goes untreated is causes death through dehydration. Hemolytic unemic infections
• In USA disease (73,000-70 deaths, e.g. deadly "Jack-in-the-Box" or eating red meat is frequent by having serotype which can only self limiting, diarrhea and is caused by endotoxin.

Salmonella species info

• Is a rare intestine bacteria not found in normal intestine, more or bacterial enterics
• Different strain are also dangerous
• S. Typhi will often cause Typhorid fevers in the human but may have different types of routes it performs. Is mostly in poor countries and has a high fatality count.
• 20000 deaths of 21 million infections

Samonella and enteric info

• Can have spread through water and food contamination. The water contamination has typhoid fever, that has spread around the world. Also found in cattle animals but not very harmful and spread through contact.
• The infection is most common with contamination and resolves 2-7 days of symptoms. Avoid antibiotics
• Shigella, is high in children under 15 who have sex. This can cause bloody stool that may often result in death. Is also used in other infections.