Atypical Agents of Respiratory Infections

ERI DIAN MAHARSIBAG.MIKROBIOLOGI

FKUY

Teaching Objectives:

• Know the general morphology & physiology of the organism

• Know clinical symptoms• Know the mechanism

pathogenesis• Know the diagnostic• Know preventive procedures

Legionellae•Family : Legionellacae•>> species & >> serogroup•Patogen >>: L.pneumophyla•Gram (-),pleiomorphic rods•Obligate aerob•Capable of replication in alveolar macrophages

Legionella pneumophila• Naturally found in water,cooling towers,water

systems• Patient with chronic pulmonary disease are

@highest risk• L.pneumophila nosocomial infection• Disease: Legionnaires disease (severe pneumonia);

Pontiac fever (influenza- like illness)• Transmission: enviromental to man• not man to man• Diagnosis: • Gram staining:difficult• direct & indirect fluorescent antibody (IFA)• Culture: buffered charcoal yeast extract agar

(BCYE),grows after 3 days incubation.

Mycoplasma• Family : Mycoplasmataceae• Mycoplasma pneumoniae is the

most common type of atypical pneumoniae

• >> species of mycoplasmas but !! Human pathogens: M.pneumoniae

M.hominis M. genitalium Ureaplasma urealyticum

Organism Disease

M. pneumoniae Upper respiratory tract disease,tracheobronchitis, atypicalpneumonia, (chronic asthma??)

M. hominis Pyleonephritis, pelvicinflammatory disease,postpartum fever

M. genitalium Nongonococcal urethritis

U. urealyticum Nongonococcal urethritis,(pneumonia and chronic lungdisease in premature infants??)

Diseases Caused by Mycoplasma

BASIC• The smallest free-living bacteria but the

extremely smallest is Ureaplasma → T-strains (tiny strains)

• The smallest genome size→lack many metabolic pathways → require complex media for the isolation

• Mycoplasmas are facultative anaerobes ,except for M.pneumoniae obligate aerobe

• No cell wall → that distinguishes it from other bacteria → can assume multiple shapes

Pathogenesis

• Major virulence factors 1.M.pneumoniae : Adherence protein called P1

• 2.Toxic metabolic product: H202 dan superoxide

Diagnosis

• Early: clinical grounds• Laboratory diagnosis:• Microscopy Absence of a cell

wall→ not usefull• Culture (+) in 2-3 weeks

difficult → not usefull• Serology: CFT ELISA

Prevention

• NO VACCINE• Prevention: avoid close

contact

M. HOMINIS & U.UREALYTICUM

• M.hominis → pyelonefritis• U.urealyticum → NGU• Diagnosis: culture• Prevention : proper barrier

protection or abstinensia

Klebsiella pneumoniae

• Can cause pneumonia• >> but more commonly implicated in hospital-

acquired urinary tract and wound infections, particularly in people with weakened immune systems.

• Lobar pneumoniae often occur in the elderly,diabetics,&alcoholism

• Problem in hospitals because, because it can cause outbreaks

Klebsiella pneumoniae

• Gram (-),rods, capable aerobic/anaerobic,capsulated

• Capsule inhibit phagocytosis

Protocol Klebsiella pneumoniaeHow to distinguish enterobacteriae

Chlamydia pneumoniae /Chlamydophila pneumoniae

Property C.trachomatis C.psitacci C.pneumoniae

Host range >>>humans Birds, mamals,

human (rare)

Humans

Elementary body

morfology

Round Round Pearl-shaped

Inclusion morfology

Round,vacuoler Varible,dense Round,dense

Glycogen containing inclusions

yes no no

Plasmid DNA

yes yes no

Pathogenesis - C. pneumoniae

• Person to person spread via aerosolized droplet

• Pathogenesis:litlle known• Caused:

pneumonia,bronchitis,pharyngitis,&flu like syndrome

Diagnosis - C. pneumoniae

• Difficult• Often asymtomatic or unrecognized• Diagnosis: • Specimen:throat swab,nasopharyngeal

swab,bronchoalveolar lavage fluids,sputum→culture→PCR

• Serology: CFT (complement Fix test) → not specific• IFA using EB as Ag → more reliable

Coxiella burnetii • Query fever / Q fever

• Zoonosis

• Potensial bioterorism

• Basic: Obligate intracellular, gram negative,cocobacillus

• Transmiison: inhalation,unpasteurized milk,tissue fluids

• Risk individu: man who come into contact with infected

animals, esp placenta (veterinarians,farmers)

Coxiella burnetii• Smaller than ricketsiaa• In contrast to ricketsia: C.burnetii

can survive extracellular, however it can be grown only in lung cells

• The organism can exist in 2 antigenic states

• When isolated from animals, C.burnetii in a phase I form → highly infection

• When grown in cultured cells lines → a phase II form→ not infectious

Clinical symtoms• Acute Q fever• Flu like syndrome • Pneumonia & granulomatous hepatitis• Diagnosis: serologic: ↑ titer 4x of antibody to phase 2

(Ig M & Ig G)

• Chronic Q fever (> 6 bulan)• Endocarditis & meningoencephalitis• Diagnosis: ↑ titer 4x antibody to phase 1&2 (IgG &

IgM)

Borellia vincentii• Spirochetes,anaerobic,Gram (-)• Cause: Vincent’s disease/Vincent’s

angina• Risk factors such as stress, poor

diet and nutrition, tobacco usage, and already having a systematic disease

• Symptoms include foul breath, ulcers in the inter-dental papillae, ulcers on the gums that easily bleed,pharyngitis

Referensi

• DIAGNOSTIC MICROBIOLGY : BAILEY & SCOTT”S

• MIKROBIOLOGY KEDOKTERAN:JAWETZS,MELNIC,ADELBERG