1. Klebsiella
Dr Kamran Afzal
Asst Prof Microbiology

2. Enterobacteriaceae
 Gram-negative rods (2-5 by 0.5 microns)
 Most motile with peritrichous flagella
 Shigella and Klebsiella are non-motile
 Oxidase negative
 Catalase positive
 Facultative anaerobes
 Reduce nitrates to nitrites
 Breakdown glucose and other CHO by fermentation with
the production of either acid or acid with gas
 Growth can occur readily on NA, BA, MacConkey’s agar
 Do not form spores
 Grow readily at 35-37oC, except Yersinia (25o-30oC)

3. Microbiological Properties
 Many genera
 Escherichia, Salmonella, Shigella, Klebsiella, Proteus,
Enterobacter, Yersinia, etc
 Some strains opportunistic pathogens
 Some strains true pathogens
 Salmonella, Shigella, Yersinia, some strains of E. coli

4. Classification of Enterobacteriaceae
Enterobacteriaceae
Lactose fermenters
Non-lactose fermenter
E. coli, Citrobacter,
Salmonella, Shigella
Klebsiella, Enterobacter
Proteus, Yersinia
There are several selective and differential media used to
distinguish between LF and NLF
MacConkey agar
Eosin Methylene Blue (EMB) agar
Salmonella Shigella (SS) agar
Triple Sugar Iron (TSI) agar

5. Classification of Klebsiella
 Enterobacteriaceae of clinical interest
 Genus: Klebsiella
 Species:
 K. pneumoniae
 ssp. pneumoniae
 ssp. ozaenae
 ssp. aerogenes
 ssp. rhinoscleromatis
 K. oxytoca

6. Description
 Straight Gram Negative Rods
 Pronounced capsule
– Extremely mucoid colonies on media rich in CHO
– Complex acid polysaccharides
– Glucoronic acid and pyruvic acid
– K antigen of E. coli resembles capsule of Klebsiella
 Non-motile, but most strains have fimbriae
 370C (12-430C)
 Facultative anaerobes
 No hemolysis on sheep or horse blood agars

7. Antigenic structure
 80 Capsular (K) antigens
 Gram stain
 Capsular ‘swelling’ reaction
 CCIE
 ELISA
 5 Somatic (O) antigens

8. Virulence factors and Pathogenesis
 Capsule
 Anti phagocytic
 Prevents from complement mediated
bacteriolysis
 LPS
 Prevent from complement mediated
bacteriolysis
 Adhesins (Fimbrial and non-fimbrial)
 Type-I and Type-III
 Adhesion to host tissues

9.  Toxins
 Heat labile and heat stable toxins
 Role not well defined
 Enzymes
 β-lactamase and ESBL

10. Lab Diagnosis
 Specimens
 Culture
 Highly mucoid colonies on NA, BA, MA and DCA
 After 24/48 hrs incubation at 370C aerobically
 Gram stain
 Gram-negative rods
 Arranged in singles

11.  Colonial morphology
 Low convex, grey, mucoid or smooth colonies on nutrient
agar and blood agar
 Non-hemolytic
 Pink colonies on MacConkey agar and DCA indicate
lactose fermentation

12.  Biochemical Reactions
 Conventional sugar set
– Lactose –sucrose – glucose – mannitol
– maltose – citrate – VP –indole –
urease – TSI
 API / QTS
 Molecular Techniques

13. IMViC Reactions
I M Vi C
Escherichia coli + + – –
Proteus vulgaris + + – –
Klebsiella pneumoniae– – + +
Klebsiella oxytoca + – + +
Enterobacter spp. – – + +
Serratia marcescens – – + +
Citrobacter freundii – + – +
Citrobacter koseri + + – +

14. Pathogenicity
 Community acquired infections
 UTI
 Bronchopneumonia
 ‘Friedlander’s pneumonia’
 Multiple abscess formation in lungs
 Hospital acquired infections
 Surgical-site infections
 UTI
 Bronchopneumonia
 Bacteremia – high mortality rate
 Central nervous system (neonatal meningitis)
 Bacterial peritonitis, abdominal abscess

15.  K. rhinoscleromatis
 Rhinoscleroma – Ch. URT disease – granulomatous infiltrations
of nasal submucosa
 K. ozaenae
 Atrophy of nasal mucosa

16. Treatment
 Clinical isolates produce β-lactamase, ESBLs
 Resistant to Ampicillin and Cephalosporins
 Addition of anti – β-lactamase such as clavulanate
 Usually susceptible to
 2nd, 3rd and 4th generation Cephalosporins
 Fluoroquinolones
 Aminoglycosides
 Carbapenems

17. Proteus

18. Species of Proteus
 Proteus mirabilis
 Proteus vulgaris
 Proteus myxofaciens
 Proteus penneri

19. Proteus
 The genus is named after a Greek
sea deity Proteus
 The god is flexible, versatile and
adaptable and, like the flowers,
assumes many different forms

20. Virulence Factors
 Urease activity
 Protease
 Fimbriae
Motility test
 Haemolysins
 Motility
 Swarming

21. Pathogenicity
 P. mirabilis -70-90 %
 UTI – Commonest site
 Young / elderly patients
 High concentration of Urea in urine
 Superficial septic lesions
 Meningitis
 Osteomyelitis
 Septicemia
 Otitis media

22. Lab Isolation and Identification
Morphology
 GNR, 1 – 3 um
 Motile-peritrichate flagella
Cultural Characteristics
 Grow well on ordinary media
 Swarming
 Continuous
 Discontinuous
 Faint ammonia / fishy odor

23. Biochemical reactions

24. Swarming
 Characteristic but not unique
 Serratia marcescens
 Vibrio parahaemolyticus
 Pseudomonads
 Bacillus
 Continuous swarming
 Discontinuous swarming
 Ascending infection

25. Anti-swarming Agents
 Increasing Agar concentration 3-4 %
 Incorporation into media of a polyvalent-H anti-sera
 Incorporating growth inhibitors
 Sulphonamides Neomycin
 Chloral Hydrate Barbiturates
 p-Nitrophenyl Glycerol
 Incorporation of
 Detergents
 Bile Salts-MacConkey Agar
 Electrolyte Deficiency- CLED

26. Antimicrobial Susceptibility
 P. mirabilis resistant to Polymyxin B and Colistin
 P. mirabilis sensitive to
 Nalidixic Acid and other Quinolones
 Semi synthetic Penicillins – Mezlocillin, Azlocillin, Piperacillin,
Carbenicillin and Ticarcillin
 Most Aminoglycosides
 Carbapenems

27. Antimicrobial Susceptibility
 P. vulgaris resistant to
 Penicillin, Ampicillin and many Cephalosporins like Cefazolin
and Cefamandole
 Inducible β-Lactamase (Cefuroximase) – Cefuroxime,
Cefotaxime
 P. vulgaris sensitive to
 Ceforoxime, Cefotaxime and Cefoxitin
 Quinolones
 Most Aminoglycosides
 Carbapenems

28. Urinary Tract Infection

29. Epidemiology
 One of the commonest infections
 Factors influencing prevalence/incidence
– Age and sex
– Diseases of urinary system
– Obstruction in urinary tract
– Instrumentation
– Predisposing diseases
(DM, neuropathies, pregnancy)

30. Urinary Tract Infection
 Lower tract infection
– Cystitis
– Urethritis
 Urethritis in men
 Urethritis in women
– Prostatitis and epididymitis
 Upper tract infections
– Acute pyelonephritis
– Chronic pyelonephritis

31. Urinary Tract Infection
 In adult women  Specific
 In adult male – Tuberculosis
– Fungal
 In the elderly
– Chlamydial
 In children – Mycoplasmal
 Transplant recipients – Parasitic
 Catheter associated

32. Pathophysiology
 Ascending infection
– Colonize vaginal introitus, urethra, bladder
– Prostate - Recurrent UTI
 Haematogenous infection (less common)
– Acute pyelonephritis may be due to bacteremia
– Renal abscess due to bacteremia and endocarditis

33. Pathogenesis
(Bacterial factors)
 Inoculum size
 Virulence of the organism
 Bacterial attachment
 Antigenicity
 Toxin production
 Other factors (urease production)

34. Pathogenesis
(Host factors)
 Factors which facilitate ascent of infecting agent
– Patients with indwelling catheters
– Urethral, prostate or bladder surgery
– Sexual intercourse
– Vaginal prolapse and length of urethra
– Poor personal hygiene
 Factors which cause stagnation of urine
– Inadequate fluid intake/urinary output
– Inadequate bladder emptying
 Humoral or cellular factors
– Ig A and IgE
– Phagocytic activity of uroepithelium

35. Pathogenesis
(Host factors)
 Vesico-ureteric reflux
 Impairment of neurogenic control of bladder
 Obstruction in urinary tract
– Urethral stricture
– Stone in the urinary tract
– Prostatic hypertrophy
– Pregnancy
– Growth in the urinary tract
– Bladder diverticula
 Miscellaneous
− Contraceptive diaphragm
− Spermicide

36. Clinical Manifestations
 Lower tract infections
– Acute cystitis
– Urethritis
 In women
 In men
– Prostatitis
 Upper tract infections
– Pyelonephritis
– Renal abscess

37. Microbiology
 Bacteria
– Enterobacteriaceae
– Pseudomonads
– Enterococci
– Staphylococci
 Fungi
– Candida albicans and other candida spp.
– Torulopsis glabrata
 Viruses
– Varicella-zoster virus (Haemorrhagic cystitis)
– Adenovirus type 8 (Haemorrhagic cystitis in children)
– Measles, mumps, CMV

38. Microbiology
 Special
– Chlamydia trachmomatis
– Mycoplasma hominis
– Neisseria gonorrhoeae
– Trichomonas vaginalis
– Mycobacteria
 Diagnostic value
– Typhoid salmonellae
– Leptospira
– Schistosoma

39. Laboratory Diagnosis
 Microscopic Examination of Urine
– Pyuria
 10 WBCs per HPF (centrifuged urine)
 Sterile pyuria (acute urethritis, renal tuberculosis, foreign
bodies, tumour of urinary tract, non-bacterial infections)
– Bacteriuria
 >105 CFU/ml
– Stain (Gram, ZN and other)
 1 bacterium per oil immersion= 105 CFU/ml
– Microscopic exam of spun urine
 Pus cells/WBCs
 20 bacteria per oil immersion= 105 CFU/ml

40. Laboratory Diagnosis
 Urine Culture
– Clean-catch urine specimen
 Women (washing perineal area from front to back)
 Men
 Midstream collection
 Other collections (suprapubic, from catheter)
– Urine culture interpretation
 Clean-catch urine
 Straight catheter and suprapubic aspiration
 Indwelling catheter
 Limitations of urine culture
– Transport time

41. Laboratory Diagnosis
 Routine culture
– Estimation of bacterial count
 Calibrated wire loop
 Measured filter paper strips
 Automated equipment
– Culture media
 CLED Agar
 MacCONKEY Agar
 Special culture
– Blood agar anaerobically with 5-10% CO2 (Mycoplasma)
– Selenite F or TT broth
– LJ Medium or Bactec B12 medium
– Sabouraud agar

42. Laboratory Diagnosis
 Rapid diagnosis tests
– Leukocytes esterase dipstick test (Pyuria)
– Nephlometry
– Bioluminescence
– Colorimetric filtration system
 Blood culture
Patients
– Fever
– History of rigors
– Hospitalized

43. General Management Principles
 Nonspecific treatment
– Hydration
 General principles of antimicrobial therapy
– Choice of antimicrobial agent
 Resistance to common antimicrobials
 Dose modification in renal functional impairment and end
stage renal disease
 Oral and parenteral therapies
– Duration of therapy

44. General Management Principles
 Determinants of antimicrobial therapy
– Age and sex
– Asymptomatic versus symptomatic bacteriuria
– Localization of the site of infection
 Invasive techniques
 The noninvasive technique
– Recurrent UTI
 Reinfection
 Relapse