Hospital acquired infections

Antimicrobial Stewardship

• 'An organisational or healthcare‑system‑wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness'.

Treatment for C.difficille

• 15 - 25% respond to conservative treatment • If possible, STOP antibiotics - allows re-establishment of normal colonic micro flora and reduces risk of relapse • Supportive therapy (observe for sepsis, rehydrate, toileting, etc.) • Dietician referral - Aim for balanced, nutritional oral intake with good fibre content

Daptomycin

• A cyclic lipopeptide with activity against most Gram-positive pathogens, including vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus -Has a unique mechanism of action that results in destruction of the membrane potential. The rapid bactericidal activity of daptomycin makes it an attractive antibiotic for serious Gram-positive infections

5th generation cephalosporins with MRSA activity

• Ceftaroline • Ceftobiprole

Plasmids contain resistance genes to

• Ciprofloxacin • Trimethoprim

Causes of nosocomial infections

Presence of many microorganisms --> Bacteria mostly Patients with contagious diseases Overcrowding Use of contaminated instruments Immunosuppressed and weakened patients Chain of transmission Diagnostic procedures

Therapeutic options to prevent antibiotic inactivation

- Choose antibiotic that is stable to the inactivating enzyme • e.g. cefuroxime instead of amoxicillin • e.g. amikacin instead of gentamicin - Combine antibiotic with an enzyme inhibitor • e.g. co-amoxiclav instead of amoxicillin - Choose different class of antibiotic e.g. ciprofloxacin instead of amoxicillin

Invasive MRSA infections include soft tissue infections like

- heart valve infections - bone infections - abscesses in organs (painful collection of pus, usually caused by a bacterial infection) - joint infections - bloodstream infection (sepsis, "blood poisoning")

You are more likely to develop sepsis if:

- recently had surgery - a urinary catheter fitted - in hospital for a long time

Extended spectrum beta Lactamase (ESBL)

-Bacteria that produce enzymes that breakdown antibiotics, making them resistant to Cephalosporins. The most common of-producing bacteria are some strains of -E.scherichia coli and and Klebsiella peumoniae. E-coli-> Able to resist penicillins and cephalosporins and are found most often in urinary tract infections (UTI's). -

Diagnosis of C.difficile

-Requires a positive for a minimum of two tests: - Glutamate Dehydrogenase (GDH) - identifies the presence of the organism through their antgen - Toxin tests; either: • Enzyme-linked immunosorbent assay (ELISA) • Polymerase Chain Reaction assay (PCR)

E.coli

A Gram-negative, facultatively anaerobic, rod-shaped, coliform bacterium that is commonly found in the lower intestine of warm-blooded organisms

Bacteraemia

A bloodstream infection caused by bacteria.

Meropenem

A broad-spectrum bacteria that can kill any type of bacteria

Enterococcus faecalis can be treated with what other antibiotic?

Amoxicillin

Antibiotic inactivation

Bacteria may evolve the ability to enzymatically inactivate an antibiotic eg. - b-lactamases and carbapenemases - Aminoglycoside-modifying enzymes

Trimethoprim

Can kill normal S.aureus but not MRSA

Common species of glycopeptide resistant enterococci (GRE)

E. faecalis and E. faecium-> also resistent to Amoxicillin

AmpC beta-lactamases

Enzymes which convey resistance to penicillin, second and third generation cephalosporins and cephamycins.

Sepsis is usually associated with other conditions like in the

GI tract GU tract Pelvis Lower respiratory tract Vascular system Heart and cardiac vasculature

Sepsis

Life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion.

Medical term for a hospital-acquired infection

Nosocomial • Sometimes also known as healthcare associated infections

Ciprofloxacin

Not only has no MRSA activity but can select out MRSA and result in an MRSA bacteraemia.

Medicines inactIve against MRSA

Peniciline and cephalosporins

Hospital Acquired Pneumonia (HAP)

Refers to any pneumonia contracted by a patient in a hospital at least 48-72 hours after being admitted. -Usually caused by a bacterial infection, rather than a virus.

Exotoxins

Toxic substances that bacteria secrete into their environment

Medicines actIve against MRSA

Vancomysin Telcoplann Dxycycline Rifampicin Clindamycin Trimethoprim Gentamicin Linezolid Daptomycin

Common bacteria involved in HAP

• Pseudomonas aeruginosa • Staphylococcus aureus, including methicillin-susceptible S aureus (MSSA) and methicillin-resistant S aureus (MRSA) • Klebsiella pneumoniae • Escherichia coli

Glycopeptide Resistant Enterococci (GRE)

• Species frequently found in bowel of normal, healthy individuals • Only a few species have potential to cause infections in humans • May cause a range of illnesses including: - Urinary tract infections, - Bacteraemia - Wound infections • Resistent to glycopeptide antibiotics including Vancomycin and Teicoplanin

Clostridium difficile (C. Diff)

• Spore-forming anaerobic Gram-positive bacillus bacterium • Spores facilitate the organism's survival in conditions of adversity (resistant to heat, drying, stomach acids, alcohol and some chemicals). Produces exotoxins A and B. Usual human habitat large intestine (very little oxygen) • Also found in soil • Faeco-oral transmission -They spend time on spores

Nosocomial infection

• Strictly and specifically an infection "not present or incubating prior to admittance to the hospital, but generally occurring 48 hours after admittance. "

Clinical presentation of C. Diff Associated Diarrhoea (CDAD)

• Toxins cause inflammation of the intestinal wall resulting in spectrum of disease: - Antibiotic associated diarrhoea (AAD) - Antibiotic associated colitis (AAC) - Pseudomembranous colitis (PMC) - Fulminant colitis