Microbiology:- TOPIC:-Acid Fast Bacilli for B.Sc( Nursing) 1st Year students

1. ACID FAST BACILLI
MYCOBACTERIUM TUBERCULOSIS
BY
G.R. JAYA SREE

2. INTRODUCTION
 LONG
 SLENDER
 STRAIGHT
 SLIGHTLY CURVED Bacilli
 Arranged in pairs.
 The Organisms are stained with ZIEHL NEELSEN’S Staining ot acid fast staining
technique, using 20% sulphuric acid as decolorizing agent.

3. Mycobacterium Tuberculosis
This Photo by Unknown Author is licensed under CC BY-SA
This Photo by
Unknown
Author is
licensed
under CC BY-
SA

4. PATHOGENICITY
 Source of Infection: Pt suffering from Pulmonary TB.
 The bacilli sheds in sputum in a pt who coughs out and the bacilli are released as a
droplets into the air.
 These droplets get dried , leaving bacilli in dried mucus and they are called as
Dried Nuclei.
 1000’s of droplet nuclei are released after a single cough spell.
 Being light they remain suspended in air and are inhaled.
 Mode of Transfer: Frm Person to Person is Inhalation ,The Bacilli Get into Alveoli
and settle in the lung to produce Infection

5. Pathogenicity (contd)
 Pulmomary TB are of 2 types
 1.Primary Infection(Primary Complex)
 2.Post Primary Infection(Adult onset Tuberculosis)

6. Primary complex
 This is usually seen in children below 14 yrs,
 Symptoms: Fever, loss of wt and loss of appetite. Fever in TB is evening rise of
Temperature. Cough and sputum are not seen in Primary complex.

7. Post Primary TB
 Acquired by Inhalation of Droplet Nuclei, or Reactivation of Primary Complex.
 The predispoaing Factors for Tb are:
 Over crowding
 Poverty
 Malnutriton
 DM
 Prolonged Rx with Corticosteroids or HIV/AIDS: This includes evening rise of temp,
night sweats, loss of wt, loss of appetite, cough with production of bloody sputum,. If
left untreated, the pt go complications like MILIARY TB, SUDDEN HEAMORRHAGE AND
DEATH, Respiratory Failure d/to collapse, Fibrosis of Lung, or empyema

8. Extra Pulmonary Tb
 Organism enters into BLOOD STREAM and spread into other organs, settle and
produce EPTB.
 Various types of Extra Pulmonary Tb are :
 Meningitis
 Pleual Effusion
 Abdominal TB
 Tuberculous Lymphadenitis
 Tuberculous Pyelonephritis

9. LAB DIAGNOSIS
 Sample Collection: Sputum Sample
 Direct Smear Examination: ZIEHL NEELSEN’S TECHNIQUE
 Concentration Technique: PETROFF’S METHOD
 Culture: LOWENSTEIN-JENSEN’S MEDIUM
 Animal Inoculation: Guinea Pig Inoculation
 Skin Test(Mantoux Test):

10. Lab Diagnosis For EPTB
 DSE Is difficult. Demonstration of M.TB Antigen in the samples by PCR IS THE
METHOD OF DIAGNOSIS. Detects the presence of DNA OF M.TB.

11. Antibiotic Sensitvity
 Antibiotic Resistance is reported in this organism.
 Previously it is sensitive to Primary Anti Tuberculous Drugs like: INH, PAS,
STREPTOMYCIN
 D/to Mutational Changes , DEVPT of Resistance to INH,
 Serious Complication: MDR-TB Means Multi drug resistance to INH, Rifampcin.
 MDR-TB If seen in HIV +Ve , it is still more serious

12. HIV-TB
 Cell Mediated Immunity is affected… d/to loss of CD4 cells. Id strain is MDR-TB,
the situation is worse.

13. VACCINATION
 BCG
 0.1 ml Intradermally to deltoid muscle

14. APPLICATION TO NURSING
 P.TB pts – special wards
 Staff should be vaccinated
 Wearing Masks to prevent Droplet Infection
 Sputum cups- sterilised in the Autoclave
 Nurse should counsel the patient to adhere Anti tuberculous therapy by DTC.
Awareness about RNTCP, Follow ups