Mycobacterium

Dr.Gh.Hamzehloo

ی پ رد هک یجیاتن و دهد یم خر هاگشیامز ا حطس رد هک ی یاهدادخر : دراد

هب کو تفرگ کشم خر ماجنا رد درم ه هاگشیامز ا هداد هابتشا ک نیا یدعب یطیحم نیمه .

تشاد تاشیامز ا یگدولا زین رگید هفرس تلع رد و هب اما نارامیب نزو دش رما زا شهاک ملاعا نیا دروم هک 14 ،بت تبثم دومن رد هک هکیلاح ،درم ضقن داد ن ا ار یلبق ناشن

دوب

رد دش طلخ

هداد

ی

خر

شریذپ سیزولکربوت هجیتن تفرگ

نام

ماجنا

رد

و

ی

یناتسرامیب هک شیامز ا دیدرگ یرتشیب

هجیتن

شرازگ

حیحص مزلا رد ریغ هک

.

رد دش هلاس هتخانش یفنم یاه

صیخشت ینامرد

یسررب

یبولطمان

83 سیزولکربوت

رد

درم کی روموت نتشاد .

دوب

ریخات تلاخادم ضراوع

هداد – – – تست خر .

دوب

دش تفای ،اهیگدول ا رگید زا یعاونا

–

تاشیامز ا هرابود ات دنراد رارق هلخادم تحت ار رامیب 200 یسررب نیا رد هک دوب .

دومن یا عفر ار ههام 6 لکشم یسررب .

دنمزاین دنهد لکشم ماجنا ار

x

،هاگشیامز ا یاه هیور نیا ی لح هعشا رد رییغت

– – جی اتن .

هب زین تشاد و دوشیم لنسرپ دهاوخ یورین لابند ،یژرنا هب ،تقو فلاتا نارامیب هب رجنم دنهدیم یارب خر ار اههاگشیامز ا هابتشا رد هک یتاهابتشا تاشیامز ا

Important Human Pathogens

Mycobacterium tuberculosis Mycobacterium leprae

(uncommon)

Mycobacterium avium-intracellulaire Complex (MAC) or (M. avium)

MYCOBACTERIUM

•

Aerobic bacilli

• • •

Cell wall Acid-fast bacilli Very slow growing – non spore forming non motile – rich in lipids

MYCOBACTERIA ASSOCIATED WITH HUMAN DISEASE Mycobacterium Environmental contaminant Reservoir

M tuberculosis

No Human

M bovis

No Human, cattle

M leprae

No Humn Rarely Water, cattle

M kansasii M marinum M scrofulaceum M avium intracellulare M ulcerans M fortuitum M chelonae

Rarely Possibly Possibly No Yes Yes Fish, water Soil, water Soil, water, birds Unknown Soil, water, animals Soil, water, animals

CLASSIFICATION OF MYCOBACTERIA ASSOCIATED WITH HUMAN DISEASE Mycobacterium Clinical significance Pigmentation Growth Unclassified

M Tuberculosis , M bovis M ulcerans

Strict pathogens No No Strict pathogen -

M leprae

Runyon Group 1

M marinum , kansasii

Runyon Group 2 Usually pathogenic Photochromogens slow

M scrofulaceum

Runyon Group 3

M avium intracellulare

Rarely pathogenic Pathogenic in immunocompromised Scotochromogens slow No slow Runyon Group 4

M fortuitum, M chelonae

Rarely pathogenic No ‘rapid’

Lipid-Rich Cell Wall of Mycobacterium

Mycolic acids CMN Group:

Unusual cell wall lipids (mycolic acids,etc.) (

P

urified

P

rotein

D

erivative)

Acid-Fast (Kinyoun) Stain of Mycobacterium

NOTE : cord growth

(serpentine arrangement) of virulent strains

Photochromogenic Mycobacterium kansasii on Middlebrook Agar

NOTE

: Mycobacteria pathogenic for humans can be differentiated (

Runyon Groups

) by: 

speed of growth

(all are slower than most other pathogens) and by  production of

pigments chromogenic

(in light, in dark, or none)

Improved Mycobacterial Isolation Medium

Pathogenic Mycobacterium spp.

BCG AIDS patients

Mycobacterial Clinical Syndromes

Laboratory Diagnosis of Mycobacterial Disease

Nucleic acid probes Nucleic acid sequencing

Differential Characteristics of Commonly Isolated Mycobacterium spp.

Mycobacterium tuberculosis

Mycobacterium tuberculosis

• Causes tuberculosis • Classic human disease • Pathogenesis • Transmission • Clinical presentations • Diagnosis • Treatment • Prevention

Mycobacterium tuberculosis Infections

Mycobacterium tuberculosis Infections (cont.)

Positive PPD + Chest X-Ray + MDR-TB a serious global health threat BCG

(bacille Calmette-Guerin) = attenuated

M. bovis

Typical Progression of Pulmonary Tuberculosis



Pneumonia



Granuloma formation with fibrosis



Caseous necrosis

• Tissue becomes dry & amorphous (resembling cheese) • Mixture of protein & fat (assimilated very slowly) 

Calcification

• Ca ++ salts deposited 

Cavity formation

• Center liquefies & empties into bronchi

Diagram of a Granuloma

NOTE:

ultimately a fibrin layer develops around granuloma

(fibrosis)

, further “walling off” the lesion.

Typical progression in pulmonary TB involves

caseation

,

calcification

and

cavity formation

.

PPD Tuberculosis Skin Test Criteria

PPD

=

P

urified

P

rotein

D

erivative from

M. tuberculosis

Chest X-Ray of Patient with Active Pulmonary Tuberculosis

Mycobacterium Tuberculosis Stained with Fluorescent Dye

Symptoms of Tuberculosis …

• • • • • • •

may appear years after contracting the disease Fever Night-Time Sweating Loss of Weight Persistent Cough Constant Tiredness Loss of Appetite

Pathogenesis

• Inhaled aerosols

Engulfed by alveolar macrophages Bacilli replicate Macrophages die

• Infected macrophages migrate • Develop Ghon’s focus

local lymph nodes Primary complex

• Cell mediated immune response

stops cycle of destruction and spread

• Viable but non replicating bacilli present in macrophages

EVIDENCE OF INFECTION WITH M TUBERCULOSIS Chest x-ray / positive skin test

Case Finding

• • • • •

Most common tools for case finding include: History taking Physical examination Sputum examination X-ray examination Tuberculin skin testing

CLINICAL PRESENTATION

Pulmonary tuberculosis HEALS Primary complex Asymptomatic Acute pulmonary disease Systemic spread Asymptomatic /symptomatic LATER DISEASE Renal / CNS etc REACTIVATION Post-primary tuberculosis MILIARY TUBERCULOSIS Pulmonary meningitis

DIAGNOSIS

Pulmonary tuberculosis 1 HEALS 3 1 Primary complex Asymptomatic 3 Acute pulmonary disease Systemic spread Aymptomatic /symptomatic 2 REACTIVATION Post-primary tuberculosis LATER DISEASE Renal / CNS etc MILIARY TUBERCULOSIS Pulmonary meningitis 3

DIAGNOSIS

1.

2.

3.

Evidence of infection a. Chest x-ray - hilar lymphadenopathy calcification of primary focus/LN b. Delayed hypersensitivity response to purified protein derivative (PPD) MANTOUX /HEAF TEST Evidence of active disease a. Sputum for AFB positive Evidence of active disease a. Indirect evidence of infection (Mantoux) b. Direct evidence of infection PCR / culture c. Histo-pathological evidence

Acid-Fast Smear Showing TB Bacilli

© University of Alabama at Birmingham, Department of Pathology

Recording Sputum Smear Microscopy Results

Number of Acid-fast Bacilli (AFB)

No AFB

# of Oil Immersion Fields Examine

Per 100 fields 1-9 AFB 10-99 AFB 1-10 AFB More than 10 AFB Per 100 fields Per 100 fields Per field Per field

Reported as:

No AFB seen

(No AFB per 100 fields)

Scanty, record exact figure

(1-9 AFB per 100 fields)

1+

(10-99 AFB per 100 fields)

2+

(1-10 AFB per field in 50 fields)

3+

(>10 AFB per field in 20 fields)

Why the Emphasis on Sputum Smears?

© ITECH, 2006© University of Alabama at Birmingham, Department of Pathology

Direct Microscopy is the most reliable and cost effective way to identify persons who are most likely to transmit TB to others

Primary and District Lab Services in TB control (Level 1)

• • • • • • • • • Receipt of specimens: from clinics Preparation and staining of smears ZN microscopy /recording Reporting of results Maintenance of lab register Management of reagents and supplies Internal Quality Control (QC) Collect specimen for culture and DST, send to NTRL Participation in EQA

Nyangagbwe Referral lab (Level 2)

• Activities: receive specimen for AFB and culture • Services to clinics: FM/ZN smear microscopy (smear microscopy and send results) • Support activities: (supply of reagents/ materials, training; EQA for smear microscopy including supervision) • Inoculate specimen and refer to NTRL for incubation and DST

Role of NTRL in TB Control

• Identify mycobacterium other than MTB • DST of M. Tuberculosis • TB laboratory equipment services and maintenance • Develop TB Lab manuals and guidelines • Primary link with NTP • Supervision of intermediate QA of culture and microscopy • Operational and applied research • Provide EQA and monitor peripheral labs

Mycobacterial Culture (1)

• “Gold Standard” of TB diagnosis • More expensive and more time consuming than microscopy • Requires specialised training and media to perform • Not recommended for routine case detection in Botswana

Courtesy of: Kubica G, 2007.

Eight Week Growth of Mycobacterium tuberculosis on Lowenstein-Jensen Agar

Mycobacterial Culture (2)

• • • • • • Reasons to request mycobacterial culture: Patient previously on anti-TB treatment Still smear-positive after intensive phase of treatment or after finishing treatment Symptomatic and at high-risk of MDR-TB To test fluids potentially infected with M. tuberculosis Investigation of patients who develop active PTB during or after IPT TB in health workers

TB Drug Susceptibility Testing (DST)

• DST performed on all cultures – Tests for isoniazid, rifampicin, ethambutol, and streptomycin • If found to be multi-drug resistant, then send for additional testing for susceptibility to second-line medicines

TREATMENT

• • •

Anti-tuberculous drugs

–

INAH

–

Rifampicin

–

Ethambutol

–

Pyrazinamide DOT Multi-drug resistant tuberculosis

PREVENTION

• Incidence declined before availability of anti-

tuberculous drugs

• Improved social conditions

- housing /nutrition

• Case detection & treatment • Contact tracing • Evidence of infection / disease • Treatment of infected / diseased contacts

ROLE OF IMMUNIZATION BCG (bacillus Calmette Guerin)

نامزاس یدوجوم و دیرخ کرادم و دانسا لنسرپ لرتنک ،دنیارف لرتنک لرتنک زین و تیفیک یهاگشیامز ا یاه هنومن نارحب تیریدم تیمه ا زئ اح یفیک متسیس لماع 12 تازیهجت تاعلاطا تیریدم یبایزرا یاه تیلاعف زا یا هعومجم ناونع هب هک هدش گنهامه و دننک یم لمع ییاه کولب متسیس راتخاس ی هدنزاس .

تیفیک متسیس دنشاب یم تیفیک دنیارف دوبهب و ءاقترا رادم یرتشم تامدخ ینمیا و تلایهست

نامزاس لنسرپ ازیهجت ت هریخذ و دیرخ یدوجوم ی

یراک نایرج ریسم

کرادم دانسا و ،دنیارف لرتنک و تیفیک لرتنک یاه هنومن تیریدم یهاگشیامزآ دادخر تیریدم تیریدم تاعلاطا یبایزرا دنیارف ی هعسوت یرتشم تامدخ رادم و تلایهست ینمیا

Process Management

PLAN – DO – CHECK – ACT CYCLE ACT PLAN CHECK DO

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