lecture 5.pptx
- 1. Vinnitsa National Pirogov Memorial Medical University/ Department of microbiology Lecturer: ass.-prof.Vovk I.M. Bacteria causing hospital and secondary bronchitis and pneumonia, specificity of etiology in different age groups. Ventilator-associated pneumonia (VAP). Laboratory diagnostics.
- 2. ACUTE BRONCHITIS ▶ Acute bronchitis is a self-limited syndrome characterized by acute cough with or without sputum but without signs of pneumonia ▶ Acute bronchitis is primarily caused by viral infections. Most common are rhinovirus, influenza viruses, respiratory syncytial virus, metapneumovirus, coronaviruses, and adenovirus. Fewer than 10% of cases are caused by Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis
- 3. ▶ 50% of smokers; fourth leading cause of death worldwide ▶ Risk factors: cigarette smoking, environmental particulate matter, genetic predisposition ▶ Intermittent progressive airway inflammation; ▶ remodeling and loss of lung function ▶ Ciliary dysfunction; ▶ excess mucus production; ▶ impaired phagocytosis leading to bacterial colonization CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)
- 4. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) ▶ Airways of patients with stable disease are frequently colonized with Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis; respiratory syncytial virus is most frequent colonizing virus. ▶ • Microaspiration in stable disease introduces oral anaerobes (e.g., Prevotella and Veillonella spp.) into lower airway. ▶ • During acute exacerbation, bacteria or viruses or both may be isolated, with more gram-negative rods found with worsening lung function. ▶ “Atypical” bacteria are not frequently isolated. ▶ Oral or intravenously administered corticosteroids and early empirical antibiotic therapy (azithromycin) are advised for moderate to severe exacerbations ▶ Administer influenza, pneumococcal, and pertussis vaccines.
- 5. Pneumonia is a form of acute lung infection. It can cause mild to life- threatening illness in people of all ages. Some facts: People at-risk for pneumonia include children (≤ 5 y.o), adults over the age of 65 and people with preexisting health problems It is the single largest infectious cause of death in children (15% of death) Ventilator-associated pneumonia (VAP) takes the second-third place among causes of death for ICU inpatients
- 6. ACUTE PNEUMONIA Classification: ▶ Community-acquired pneumonia (CAP) ▶ Hospital-acquired pneumonia (HAP) or medical care associated pneumonia (MCAP) ▶ Ventilator-associated pneumonia (VAP) in ICU According to a cause: ▶ bacterial (more often, also named typical), ▶ other bacterial pathogens cause so named atypical pneumonia (Chlamydia, Mycoplasma) ▶ Viral ▶ Fungal ▶ Protozoan ▶ Co-infection (bacteria + viruses is the most often)
- 7. •Diabetes mellitus •Alcoholism •Malignancy •Asplenia •Age over 65 y.o. •Chronic heart, lung, liver or renal disease Risk factors for severe CAP in adults: • Age under 5 y.o. • Respiratory tract abnormalities • Undernutrition • Congenital/perinatal infections, including HIV • Not complete immunization/no immunazation • Heart and lung disease • Cystic fibrosis, CGD Risk factors for severe CAP in children: Community-acquired pneumonia (CAP) is an acute lung inflammation caused by microorganisms acquired outside a hospital or other medical facilities
- 8. In adults •Streptococcus pneumoniae* • Haemophilus influenzae • Mycoplasma pneumoniae •Staphylococcus aureus •Legionella pneumoniae •Moraxella catarrhalis In children: school age •Chlamydia pneumoniae •Streptococcus pneumoniae* •Mycoplasma pneumoniae Newborns •Streptococci B group (S.agalactiae) •Listeria monocytogenes •Escherichia coli In children: preschool age •Streptococcus pneumoniae* •Staphylococcus aureus •Haemophilus influenzae* Bacterial pneumonia: causes of CAP * -not for immunized with pneumococcal vaccine/Hib vaccine
- 9. OTHER CAUSES OF CAP: •SARS-CoV2 •Influenza virus •Adenovirus •SARS and MERS viruses •Human metapneumonic viruses Viruses: in adults •CMV and HSV for neonates •Respiratory-syncytial virus (first 12 months) •Influenza virus •Measles virus •Varicella/zoster virus •Adenoviruses, rhinovirus Viruses: in children •Candida albicans, molds for immunodeficient people •Pneumocystis jirovecii for AIDS patients Fungi and protozoa
- 10. LABORATORY DIAGNOSTICS: SAMPLING AND MODERN APPROACHES ▶ Sputum sample: Gram`s stain and culture* ▶ Endotracheal aspirate sample in intubated patients: Gram`s stain, culture, antibiotic susceptibility testing ▶ Nasopharyngeal swab or oropharyngeal swab for influenza/ covid 19 testing (in case is co-infection or viral pneumonia suspected): PCR is more preferable than rapid test ▶ Urine: pneumococcal antigen and Legionella antigen testing at suspicion for severe CAP, caused by this pathogens ▶ Blood: Blood culture in patients with severe disease as well as in all inpatients empirically treated for MRSA or P.aeruginosa OR patients with medical care- associated pneumonia (MCAP) * According to An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America(2019) it is not recommended for adult outpatients with CAP because of low quality of evidence
- 11. GRAM STAIN OF SPUTUM Streptococcus pneumoniae in patient`s sputum (left on the top) Staphylococci in the patient`s sputum (left on the bottom) Normal sputum smear with epithelial cells and oropharyngeal microbiome but without WBC (on the right)
- 12. Haemophilus Influenzae on chocolate agar Legionella pneumophilia on buffered charcoal yeast extract agar (BCYE) Streptococcus pneumoniae on blood agar
- 13. EMPIRIC THERAPY FOR CHILDHOOD CAP Bacterial pneumonia Atypical pneumonia Influenza pneumonia Outpatients (3m.-18 y.) Amoxicillin OR amoxicillin/clavunate (orally) Azitromycin OR clarithromycin (orally) Oseltamivir Inpatients fully immunized against S.pneumoniae and H.influenzae type b Ampicillin OR Ceftriaxone/cefotaxime (IV) Vancomycin may be added at suspected MRSA Azitromycin OR clarithromycin/erythrom ycin/doxycycline (IV) Oseltamivir + Zanamivir Inpatients not fully or not immunized against S.pneumoniae and H.influenzae type b Ceftriaxone/cefotaxime OR Levofloxacin (IV) Vancomycin or clindamycin may be added at suspected MRSA Azitromycin+β-lactam OR clarithromycin/erythrom ycin/doxycycline/levoflo xacin (IV) Oseltamivir + Zanamivir (for children older 7 y.) Principles of antimicrobial therapy (CAP) in Children
- 14. PRINCIPLES OF ANTIMICROBIAL THERAPY (CAP) IN ADULTS Category of patients Recommended therapy Adds CAP in outpatients without risk factors and co-morbidities Monotherapy: Amoxicillin or Doxycycline or Azithromycin Orally, not less than 5-days` therapy CAP in outpatients with risk factors and co-morbidities Combination: Amoxicillin/clavunate or cefuroxime AND macroloide (azithromycin or clarithromycin) or doxycycline OR Monotherapy: respiratory flouroquinolone (levofloxacin or moxifloxacin or Gemifloxacin) Broader-spectrum antibiotics to cover macrolide- and doxycycline- resistant S. pneumoniae, b- lactamase–producing strains of H. influenzae, many enteric gram- negative bacilli, most MSSA, and M. pneumoniae and C. pneumoniae Non-severe CAP in inpatients Β-lactam (ampicillin+sulbactam, cefotaxime, ceftriaxone) AND macrolide (azithromycin, clarithromycin) or doxycycline OR Monotherapy with respiratory fluoroquinolones Without risk factors for MRSA or P.aeruginosa Severe CAP in inpatients b-lactam plus a macrolide OR b-lactam plus a respiratory fluoroquinolone Without risk factors for MRSA or P.aeruginosa CAP in inpatients with risk factors for MRSA or Vancomycin for MRSA Piperacillin-tazobactam or cefepime or ceftazidime or aztreonam, meropenem or Risk factors: prior isolation of MRSA/P.aeruginosa from respiratory tract;
- 15. MEDICAL CARE –ASSOCIATED PNEUMONIA (MCAP) HOSPITAL-ACQUIRED pneumonia (HAP), or nosocomial pneumonia, is a lower respiratory infection that was not incubating at the time of hospital admission and that presents clinically 2 or more days after hospitalization. 1. Early HAP happens 48-120 hrs after hospitalization. Main causes: S.pneumoniae, H.influenzae, MSSA, M.catarrhalis, others. It has better prognosis 2. Late HAP arises over 120 hrs (6 days) after hospitalization. Main causes: MRSA, K.pneumoniae and other enteric bacteria, non-ferments such as P.aeruginosa. Its prognosis is worse, because multiresistant hospital isolates are quite often causes VENTILATOR-ASSOCIATED pneumonia (VAP) is defined as nosocomial pneumonia occurring in a patient after 48 h of mechanical ventilation via an endotracheal or tracheostomy tube. It is commonly classified as either early onset (occurring within 96 h of start of mechanical ventilation) or late onset (occurring more than 96 h after start of mechanical ventilation). VAP occurs in 9–27% of all intubated patients
- 16. Risk factors for nosocomial pneumonia 1. Patient-related factors: acute or chronic severe disease, coma, malnutrition, prolonged hospital length of stay, hypotension, metabolic acidosis, smoking and comorbidities (especially of the central nervous system but also chronic obstructive pulmonary disease (COPD), diabetes mellitus, alcoholism, chronic renal failure and respiratory insufficiency). 2. Infection prevention-related : deficient hand hygiene or inappropriate care of respiratory support devices 3. Procedures-related : administration of sedatives, corticosteroids and other immunosuppressants, prolonged surgical procedures (especially at thoracic or abdominal level) and prolonged/inappropriate antibiotic treatment .
- 17. LABORATORY SAMPLING FOR PATHOGEN ISOLATION Sampling: Blind tracheobronchial aspiration (TBAS), which is a noninvasive technique done by inserting a flexible catheter into the distal trachea via the endotracheal tube. Bronchoscopy with bronchoalveolar lavage (BAL) allows the sampling of the lung segments which are suspected to be affected by pneumonia Protected specimen brush (PSB) which can be advanced through a bronchoscope and has the advantage of avoiding contamination with upper airway secretions Blood for culture (!) Microscopic Analysis ▶ polymorphonuclear leukocytes and a gram stain. Quantitative Cultures: Diagnostic thresholds include: • Endotracheal aspirates 1,000,000 colony forming units (CFU)/mL • Bronchoscopic- or mini-BAL 10,000 CFU/mL • PSB 1000 CFU/mL Multiplex PCR assay for multidrug resistant genes detection
- 18. K.pneumoniae (on the left), Acinetobacter (in the center) and P.aeruginosa (on the right) in PSB-samples: encapsulated bacteria
- 19. The most dangerous pathogens (being suspected for resistance to antimicrobial therapy): 1. Gram-negative enteric bacteria such as Klebsiella pneumonia (especially ESBL-producers), Escherichia coli, Enterobacter spp. 2. Gram-negative non-ferments such as Pseudomonas aeruginosa and Acinetobacter baumannii (rarely Stenotrophomonas maltophilia, Burkholderia cepacia) 3. Gram-positive cocci including MRSA, VRSA, vancomycin-resistant enterococci, macrolide-resistant streptococci Some facts: Late HAP and VAP are often caused by hospital isolates Gram-negative microorganisms are predominant cause Late MCAP are polymicrobial in 40-60% of cases
- 21. PANNUCI algorithm. From empirical to targeted treatment on nosocomial pneumonia in ICU. Empiric treatment: Unknown colonization •piperacillin-/tazobactam or carbapenem or cefepime PLUS aminoglycoside or Quinolone Early onset without previous AT •Cephalosporins 3rd P.aeruginosa risk factors / vAP and/or AB failure •Ceftazidime/avibactam PLUS aminoglycoside OR •Ceftolozane/azobactam PLUS Quinolone K.pneumoniae risk factors for EBSL, KPC •Ceftazidime/avibactam PLUS aminoglycoside or Quinolones Targeted treatment MRSA •Linezolid or vancomycin MSSA •Cloxacillin or cefazoline Acinetobacter •colistin or cefideracol P.Aeruginosa or/and bacteremia •Ceftolozane/azobactam KPC or OXA-48 • Ceftazidime/avibactam Metallo-beta-lactamases • Ceftazidime/avibactam +AZT or • colistin or cefideracol
- 22. WHILE COMPILING LECTURE MATERIALS NEXT SOURCES WERE USED: ▶ Mandell, Douglas and Bennett`s Infectious Diseases Essentials/ J.E Bennet., R. Dolin, M.J.Blaser. – ELSEIVER, 2017. ▶ Metlay J.P. et al. Diagnosis and Treatment of Adults with Community-acquired Pneumonia: An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America//American Journal of Respiratory and Critical Care Medicine (2019). – Vol. 200 (7). – P. e45-e67, ▶ Thorell E.A., M.A.Jackson. Community-Acquired Pneumonia: Implications for the Hospitalized Child// The Hospitalist. 2005 September;2005(9) ▶ Chahine E. B. , Mayberry M. S. . Update on the Treatment and Prevention of Community-Acquired Pneumonia in Children//US Pharm. 2012;37(3):HS-12-HS-15. ▶ Shebl E.; Gulick P. G. . Nosocomial Pneumonia. https://www.ncbi.nlm.nih.gov/books/NBK535441 ▶ Zaragoza, R., Vidal-Cortés, P., Aguilar, G. et al. Update of the treatment of nosocomial pneumonia in the ICU. Crit Care 24, 383 (2020). https://doi.org/10.1186/s13054-020-03091-2 ▶ Illustration sources: https://www.wikiwand.com/; https://www.microbiologyinpictures.com/bacteria- micrographs