Respiratory tract infection and UTI by Dr. Rakesh Prasad Sah

1. Respiratory Tract
Infections
DR. RAKESH PRASAD SAH
ASSISTANT PROFESSOR
MICROBIOLOGY

2. Introduction
 Most frequently encountered ds.
 Important cause of sickness and account for 50% cases of general practitioner’s consultations.
 Air borne route
 Coughing and sneezing  spreading the infection
 Winter season between October to March

3. Predisposing Factors
RTI
Physical
damage eg.
smoking
Damage to respiratoy
tract by viral infection
Loss of defense

4. Pathogenesi
s
 SOI patient and carrier
 MOT  inhalation of aerosoles
 POE  respiratory tract
Entry
Adheres to mucosa of RT (pili or other factors)
Resist local defenses, starts multiplication  colonization
After colonization  virulence factors
Clinical symptoms

5. Types of RTI
URTI (Upper respiratory tract infection)
LRTI (Lower respiratory tract infection)

6. URTI (Upper respiratory tract infection)
 Includes airway above the glottis or vocal
cords.
 Nose
 Sinuses
 Pharynx and
 Larynx
 Typical infections include
 Tonsillitis
 Pharyngitis
 Laryngitis
 Sinusitis
 Otitis media
 rhinitis
 Symptoms includes
 Cough
 Runny nose
 Nasal congestion
 Headache
 Low grade fever
 sneezing

7. LRTI (Lower respiratory tract infection)
 Infection of trachea, bronchi, bronchioles and the lungs  LRTI
 Includes
 Bronchitis
 Bronchiolitis
 Pneumonia
 Lung abscesses
 Respiratory infection may lead to
 Bacteraemia
 Septicaemia

8. Sore Throat
 Is essentially an acute tonsillitis and / or pharyngitis
 Characterised by
 Redness and Oedema of mucosa
 Exudation of tonsils
 Pseudomembrane formation
 Oedema of uvula and cervical lymphnodes
 Viruses are most common cause of it. (80%)

9. Causative agents
 Bacterial
 Streptococcus pyogens (most common)
 Streptococcus groups C and G
 Corynebacterium diptheriae
 Haemophilus influenzae
 Bordetella pertuissis
 Treponema vincentii
 Fungus
 Candida albicans
 Viruses
 Epstein-Barr virus
 Adenoviruses
 Coxsackievirus A
 C. diptheriae, C. albicans, Strept pyogens, Treponema vincentii may lead to pseudomembrance
formation.

10. Lab diagnosis
 Symptoms caused by Streptococci & viruses are same
 Pain on swallowing
 Congested tonsils & pharynx
 Enlarged lymphnodes & pyrexia
 Untreated streptococcal tonsilitis  peritonsillar abscess, sinusitis or immune complex ds like
(rheumatic fever, glomerulonephritis)
 Specimen  Throat swabs
 Rubbed over tonsillar fossa, pseudomembrane if present, finally over post pharyngeal wall.

11.  Direct microscopy
 Gram staininig
 Albert staining
 Culture
 Blood agar
 Crystal violet agar
 Loefflers serum slope
 Potassium tellurite agar
 Sabourauds dextrose agar
 Identification
 Antibiotic sensitivity testing

12. Pneumonia
 Inflammation and consolidation of the lung.
 Types
 Lobar pneumonia
 Acute inflammation characterised by
homogeneous consolidation of one or more lobes.
 Bronchopneumonia
 Always secondary inf (follows viral infection or RT)
 Acute inflammation of bronchi and the
consolidation is scattered.
 Atypical pneumonia
 Patchy consolidation of lungs.
 Pneumonia in immunocompromised patients
 Pneumocystis jiroveci
 Staph. Aureus
 Ps. Aeruginosa
 Viral inf like CMV and Herpes
 M. tb
 Respiratory syncytial virus (bronchiolitis and
bronchopneumonia)
 Other virus include influenza, parainfluenza
viruses, adenovirus and measles virus.

13.  Bacterial cause of Pneumonia
 Lobar pneumonia
 Strep pneumoniae
 Bronchopneumonia
 Streptococcus pneumoniae
 Haemphilus influenzae
 Rarely Kleb pneumoniae, Staph aureus
 Atypical pneumonia
 Mycoplasma pneumoniae
 Chlamydophila psittaci
 Chlamydophila pneumoniae
 Coxiella burnetti
 Legionnaires disease
 Legionella pneumophila

14. Lab Diagnosis
 Specimens
 Sputum
 Blood
 Pleural fluid
 Blood for serological test
 Direct Microscopy
 Gram staining
 ZN staining
 Giemsa staining
 Culture
 Serology
 Mycoplasma pneumoniae  CFT & cold agglutionation
 Chlamydophia pneumoniae  CFT & Microimmunofluorescence with a TWAR antigen.

15. Urinary Tract Infection
 2nd most common after RTI
 UTI  ds caused by microbial invasion of the genitourinary tract that extends from the renal cortex
of kidney to the urethral meatus.
 +ce of detectable bacteria in the urine is named as bacteriuria.
 Pyuria  UTI
 Kidney, ureters, urinary bladder and proximal urethra  Sterile
 Distal urethra  not sterile, faecal flora

16. Types
 Lower UTI
 Urethritis
 Cystitis
 Prostatitis
 Upper UTI
 Acute pyelitis  pelvis of kidney
 Acute pyelonephritis  parenchyma of kidney
Ascending
Hematogenous

17. Predisposing Factors
 Gender
 Females
 Short length of urethra and its proximity to anus
 Sexual intercourse leads to introduction of bacteria into bladder.
 Pregnancy
 Obstruction to flow of urine (stone, stricture, prostatic hypertrophy and tumor)
 Neurogenic bladder dysfunction (spinal cord injury, multiple sclerosis)
 Bacterial virulence
 Reflux of urine from bladder up into ureters and sometimes into the renal pelvis.
 Genetic factors (genetically determined receptors on uroepithelial cells)

18. Clinical features
 Asymptomatic
 Symptomatic
 Dysuria
 Suprapubic pain
 Fever with rigors

19. Cuasative organisms
 GNB
 E. coli
 Klebsiella spp
 Proteus spp especially mirabilis
 Enterobacter
 Pseudomonas aeruginosa
 Serratia
 GPC
 Enterococci e.g. E. faecalis
 Staph. Aureus
 CONS
 Miscellaneous
 M. tuberculosis
 Citrobacter
 Salmonella
 Str. pyogens
 Str. Agalactiae
 Fungus
 Candida albicans

20. Lab Diagnosis
 Sample collection
 Midstream urine specimens (genitalia cleaned with soap water)
 Retract foreskin of glans of penis
 Keep labia apart
 Catheter specimen
 Directly from catheter not from collection bag
 From Infants
 Cleansing of genitalia
 Suprapubic aspiration
 Transport

21. Lab Methods
 Microscopy
 Pyruria
 Pyuria without bacteriuria  Renal TB
 Presence of urinary cast, red cells, tubular epithelial cells or atypical cells  non-infective lesions, eg.
Glomerulonephritis or tumor.
 Culture
 B.A. & M.A. with std. loop
 Loop is of 4mm holds 0.005 ml (i.e. 200 loops per ml)
 More than 105 cfu/ml.
 Identification of the organisms

22. Tuberculosis of Kidney and Urinary tract
 M. tuberculsis  acid and alcohol fast
 M. smegmatis  acid-fast.

23. Thank You