James Clayton Consultant Microbiologist Antibiotics James Clayton Consultant Microbiologist

Antibiotic groups β-Lactams Penicillins Penicillin, Amoxicillin, Flucloxacillin PO/IV Penicillins + β-lactamase inhibitor Co-amoxiclav (Amoxicillin + clavulanate) PO/IV Tazocin (Piperacillin + tazobactam) IV Cephalosporins PO/IV Carbapenems Meropenem, Ertapenem IV

Other antibiotics: Aminoglycosides Macrolides Glycopeptides Gentamicin, (Amikacin) IV Macrolides Erythromycin, Clarithromycin PO/IV Glycopeptides Vancomycin, (Teicoplanin) IV Tetracyclines Doxycycline PO Others Trimethoprim, Nitrofurantoin PO Rifampicin, Clindamycin PO/IV Ciprofloxacin PO

Streptococci Group A streptococci Group B streptococci Skin & soft tissue infection Necrotising fasciitis Tonsillitis Toxic shock, sepsis Group B streptococci Neonatal infection, UTI Other streptococci Endocarditis, abscess

Streptococci & Enterococci Strep. pneumoniae URTI, pneumonia Enterococcus faecalis / E.faecium UTI, endocarditis

Staphylococcus Staph. aureus Skin & soft tissue infection Abscess Bone & joint infection Line infections Severe pneumonia Remember MRSA (Meticillin resistant S.aureus)

E.coli & coliforms E.coli, Klebsiella, Proteus UTIs Intra-abdominal infection E.g. cholangitis, sepsis Hospital-acquired infection Remember ESBLs

Neisseria & Haemophilus N. meningitidis Meningitis N. gonorrhoeae Gonorrhoea H. influenzae Respiratory tract infection Meningitis (rare)

Pseudomonas Anaerobes P. aeruginosa UTIs (usually complicated / catheter) Hospital acquired infections Anaerobes Intra-abdominal infections Skin & soft tissue infections Abscess

7 cases

Case 1 John, 18 yrs old Sore throat for 2 days, feverish Exudate on tonsils when examined by GP Tonsillitis diagnosed. What organisms cause tonsillitis? What antibiotics are appropriate?

Coventry and Warwickshire Community Antibiotic Guidelines

Tonsillitis Majority caused by Group A streptococci Penicillin susceptibility ~ 100% Erythromycin susceptibility ~ 80% Penicillin preferred to Amoxicillin as: Narrower spectrum EBV / glandular fever reaction Oral antibiotics in a community setting

Case 2 Bob, 70 years old CXR – extensive consolidation CURB-65 = 2 COPD. 60 pack year smoking history. Retired engineer. 3 day history of cough, green sputum, malaise, raised temperature o/e crepitations, reduced air entry CXR – extensive consolidation CURB-65 = 2 No allergies

And Atypicals!

Coventry and Warwickshire Treatment Guidelines (Hospital)

Community acquired pneumonia Strep. pneumoniae ~ 30 - 40% Haemophilus influenzae ~ 5 - 10% Staph. aureus ~ 0.5 - 5% Severity of infection (CURB-65 score) Determines need for IV or oral treatment Determines need for broad vs narrow cover

Don’t forget atypicals in CAP! Legionella pneumophila ~ 1 - 5% Mycoplasma pneumoniae ~ 1 - 10% Chlamydophila pneumoniae < 10% ? Chlamydia psittaci, Coxiella < 2% Viruses including Influenza < 15% Addition of Macrolide e.g. erythromycin or clarithromycin Tetracycline e.g. doxycycline (Ciprofloxacin)

Case 3 Katie, 25 years old Presents to A&E with history of dysuria, frequency Previously well

Do all antibiotics get into urine? These do: These don’t: Penicillins (most) Amoxicillin, co-amoxiclav Cephalosporins Carbapenems Gentamicin Trimethoprim Nitrofurantoin Ciprofloxacin Vancomycin Penicillins (few) Flucloxacillin (poorly only) Macrolides Erythro & Clarithromycin Tetracyclines Doxycycline Clindamycin

Coventry and Warwickshire Treatment Guidelines (Hospital)

UTI Usually Gram-negatives as a cause Pseudomonas E.coli Other coliforms (proteus, klebsiella) Less commonly enterococci, staphylococci Pseudomonas Mainly in catheterised patients or those with underlying urinary tract disorders

Case 4 Stephen, 17 years old Admitted through A&E No allergies Lethargic, drowsy, unwell High fever Photophobia & stiff neck No allergies

Coventry and Warwickshire Treatment Guidelines (Hospital)

Meningitis Need IV therapy Neisseria menigitidis (meningococcus) Strep. pneumoniae (pneumococcus) Haemophilus influenzae (HiB) Listeria (extremes of age, immunocompromise) Need IV therapy Need antibiotics with good meningeal penetration

Case 5 Albert, 82 years old Had total hip replacement 5 days ago On review today, unwell, coughing mucky sputum Poor Oxygen sats, febrile WCC 18, CRP 280 CXR – widespread opacity No allergies, no previous microbiology samples

Coventry and Warwickshire Treatment Guidelines (Hospital)

Case 6 Ivy, 82 year old #neck of femur Had a DHS 3 days ago. Now has some erythema around the wound Tender and wound feels hot. Well otherwise Determined to be non-severe wound infection Recent MRSA screen negative Penicillin allergic (previous rash)

Coventry and Warwickshire Treatment Guidelines (Hospital)

Case 7 Rose, 75 year old Has been on medical ward for 2 weeks Diabetic, hypertensive Catheterised to measure urine output Today, unwell, high temperature, hypotensive, MEWS score = 7. No obvious cause – chest OK, abdo normal. No known allergies

Coventry and Warwickshire Treatment Guidelines (Hospital)

Blood cultures are returned positive: MRSA grown after 24 hours Flucloxacillin Resistant Erythromycin Resistant Gentamicin Sensitive Vancomycin Sensitive Rifampicin Sensitive On careful examination, a cannula site is found to be very inflamed and other sources are excluded clinically. Should the antibiotics be changed?

Sepsis Wide variety of causes May be clear cause e.g. urosepsis or unclear Needs to be treated promptly broad spectrum antibiotics IV route ‘empirical’ ‘Targeted’ therapy if a cause is found subsequently

Summary Overview / revision of microbiology Route: Oral vs IV Spectrum: Narrow vs broad Therapy Empirical vs targeted Antibiotics Single vs multiple Which antibiotics and when Allergies Resistant organisms e.g. MRSA, ESBL Guidelines will help in most cases!