K. pneumoniae, K. ozaenae and K.rhinoscleromatis

Predisposing  factors  for  Klebsiella …………..

Klebsiella and the related Serratia and Enterobacter are the most important enteric organisms other than E. coli to infect humans. Although respiratory disease is important (Klebsiella accounts for 1 % or less of community-acquired pneumonia), most clinical isolates now come from the urinary tract. All    three    genera    are    important    pulmonary nosocomial  pathogens.  However,  merely  finding these organisms growing in the sputum of a very ill hospitalized patient does not necessarily implicate the bacteria as pathogenic in that particular circumstance and may indicate colonization rather than infection. Clinical context and procurement of the sample in a sterile fashion (transtracheal aspiration, bronchoscopy) will aid in the diagnosis Chronic alcoholics, diabetics, and those with chronic lung disease are at increased risk for Klebsiella pneumonia, a difficult disease to treat because of the frequency of suppurative complications (empyema and abscess) with the associated requirement for prolonged (>2 weeks) therapy.

Change cerftriaxone to Imipenem [Ref: Harrison 18/e (new edition) p. 1247-1248]

• Penicillins were the earliest antibiotics to be developed.
• Penicillins and their related group of antibiotics were called fl lactam antibiotics because they contained a four carbon ring called fi lactam ring.
• Within a _.few years of introduction of penicillin, bacterias started acquiring resistance against penicillins by producing penicillinase
• To overcome this problem penicillinase resistant penicillins came into picture.
• Shortly afterwards, the broad spectrum penicillin and first gene- ration cephalosporins were introduced.
• They remained_, first line antibiotics_. for several years.
• Over a period of tune bacterias developed resistance even against these organisms by producing filactamase.
• fi lactamase are enzymes that break open the fi lactam ring and deactivate the antibiotic.
• The _,B lactamases hydrolyze penicillins and narrow spectrum cephalo- sporin, such as cephalothin or cefazolin, and are resistant to them.
• To counteract the problems against fl lactamases new classes of /I lactams were developed. These are cephalosporins containing oxy- minio side chain e.g. ceftizoxime, cefotaxine, ceftazidime, ceftriaxone (broad spectrums cephalosporins).

– Consequently, when these oxymino side chain containing com- pounds were introduced they were effective against a broad group of otherwise resistant bacterias.

– f3luctamases cannot hydrolyze higher generation cephalosporins with an oxymino side chain (cefotaxime, ceftizoxime, ceftazidime).

• But not long ago after these cephalosporins came into use strains of klebsiella pneumonia were discovered which were resistant even to oxyimino containing cephalosporins e.g. (cefotaxime, cefazidime, ceftriaxone)
• The mechanism of this resistance was production of extended spectrum /3 lactanzase enzyme (ESBL).

These bacterias are called ESBL bacterias

-Bacterias are classified as extended spectrum fl lactamase (ESBL) producing bacteria, when a simple point mutation occurs in genes normally responsible _.for beta lactamase mediated resistance. The mutation usually responsible is (TEM).

–  As a result of the mutation, organisms, are able to produce novel beta lactamases that can hydrolyze all the fi lactam containing antibiotics which includes even the ox-pninio group containing cephalosporins (ceftizoxime, cefotaxime, ceftazidime, ceftriaxone), Aztreonam and all the older fi lactam drugs.

• Because of their greatly extended substrate range these enzymes were called extended spectrum 13 lactamase

ESBLS are capable of efficiently hydrolyzing :-

-Folic illins

– Narrow spectrum cephalosporins

– Many extended spectrum cephalosporins

– Oxyimino group containing cephalosporins (cefotaxime, ceftazidime) – Monobactams (aztreonams)

– Beta lactatnase inhibitors (clavulinic acid sulbactam)

An important point

• None of the ESBLS described till to date are able to hydrolyze cephamycin or carbepenems (imipenenz, meropenems)
• ESBL producing organisms are associated with gram negative bacterias and most of these organisms are in the  family. Enterobacteriaeae and has been discovered in almost all members of the enterobacteriaceae family.
• The enterobacteriacea species most commonly associated with ESBL are klebsiella (Klebsiella pneumonia  predominantly) and E. coli.

Treatment of ESBL’S

• Of all the available fllactams “carbepenenzs” are the most effective and reliable as they are highly resistant to the hydrolytic activity of the fl lactamase.

– None of the ESBLS described till todate are able to hydrolyze cephamycin or Carbepenem (imipenem,  meropenem) Meropenem is the most active with MIC generally lower than those of imipenem.

• Beta lactamase inhibitors (Clavulanic acid, sulbactam, Tazobactam)
• Although ESBL activity is inhibited by clavulinic acid the only infections that may be treated safely with b lactam / f3lactamase inhibitor combinations are those involving the urinary tract.

–  In this instance _i3lactamase inhibitor concentration is high et^,ough to counteract the hydrolytic activity of ESBI:.s clavulinic acid appears more efficient than sulbactam (It takes about eight times more sulbactam to obtain a protection similar to that given by clavulinic acid).

Non 13 lactam antibiotics

• Non fi lactam antimicrobial agents (amino glycosides, fluoro- quinolones) may be beneficial however, coresistance rates against these agents are frequent.

Klebsiella pneumoniae is a well-recognized cause of community-acquired lobar pneumonia associated with cavitation.

It is found typically in alcoholic males over 40 years of age with underlying diabetes or obstructive lung disease.

Klebsiella pneumoniae mimics Streptococcus pneumoniae as a pulmonary pathogen except that Klebsiella has a greater tendency to progress to lung abscess and empyema.

Pseudomonas aeruginosa is usually associated with patients on ventilators, particularly in intensive care units.

Immunocompetent patients usually have bilateral bronchopneumonia without cavitary lesions.

ESBL +ve Klebsiella pneumoniae is resistant to cephalosporins, aminoglycosides, tetracyclines, and TMP-SMX. It is sensitive to amikacin or carbapenems.  

Ref: Russo T.A., Johnson J.R. (2012). Chapter 149. Diseases Caused by Gram-Negative Enteric Bacilli. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison’s Principles of Internal Medicine, 18e. 

A i.e. Klebsiella pneumonia

Ans.A. (Lower Lobe Involvement):

Pneumococcal pneumonia has a predilection to involve the right lower lobe, whereas Klebsiella usually affects one of the upper lobes.

Ans. is ‘a’ i.e., Klebsiella ozaena

Atrophic rhinitis (Ozaena)

Atrophic rhinitis is a chronic inflammation of nose characterized by atrophy of nasal mucosa, including the glands, turbinate bones and the nerve elements. Atrophic rhinitis may be primary or secondary : ‑

1) Primary atrophic Rhinitis:

The primary pathology is inflammation and atrophy of the nose.

Generally, atrophic rhinitis refers to primary atrophic rhinitis. Causes are : –

i) Hereditary

ii) Endocrinal pathology – Starts at puberty. Stops after menopause

iii) Racial factors – Seen more in Whites and Yellow races

iv) Nutritional deficiency – Deficiency of vitamin A, D, E and iron may be responsible for it.

v) Infective – Klebsiella ozanae, Diphtheriods, P. Vulgaris, E.coli, Staphylococci, Streptococci.

vi)  Autoimmune process – Causing destruction of nasal, neurovascular and glandular elements may be the cause.

2) Secondary atrophic Rhinitis

Specific infections, such as syphilis, lupus, leprosy, and rhinoscleroma, may destroy the nasal structures leading to atrophic changes. Can also result from long-standing purulent sinusitis, radiotherapy of the nose, excessive surgical removal of the turbinate and as a complication of DNS on the root side of the nose.

Ans. is ‘c’ i.e., Klebsiellarhinoscleromatis infection

Rhinoscleroma

• The causative organism is Klebsiellarhinosclerontatisor Frisch bacillus, which can be cultured from the biopsy material.
• The disease is endemic in several parts of world.
• In India, it is seen more often in northern than in the southern parts.
• Biopsy shows infiltration of submucosa with plasma cells, lymphocytes, eosinophils, Mikulicz cells & Russell bodies.
• The latter two are diagnostic features of the disease.
• The disease starts in the nose & extends to nasopharynx, oropharynx, larynx, trachea & bronchi.
• Mode of infection is unknown.
• Both sexes of any age may be affected.

The micro-organism shown in the photomicrograph above is Klebsiella pneumoniae.

Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium.

The test shown in the picture above represents Voges-Proskauer test.

Voges–Proskauer or VP is a test used to detect acetoin in a bacterial broth culture. The test is performed by adding alpha-naphthol and potassium hydroxide to the Voges-Proskauer broth which has been inoculated with bacteria.It is most commonly seen in cases of Klebsiella Pneumoniae.

Ans. is ‘a’ i.e., Lobar Pneumonia

Ans. is ‘a’ i.e., Lower lobe involvement

Pneumococcal pneumonias have predilection to involve the right lower lobe, whereas Klebsiella usually affects one of the upper lobes.

Ans. is ‘a’ i.e., Klebsiella pneumonia 

Pneumatoceles

• These are multiple thin walled air containing cysts.
• Staphylococcus aureus is the most common organism causing pneumatoceles and pneumatoceles are considered pathognomonic of staphylococcal pneumonia.
• E.coli and klebsiella pneumonia may have pneumatoceles

Ans. is ‘c’ i.e., Klebsiella pneumoniae

Organism’s Other Names 

Ans. is ‘c’ i.e., Klebsiella azaenae 

Laryngitis sicca (Atrophic laryngitis or laryngitis atrophica)

• It is a rare entity characterized by atrophic changes in the respiratory mucosa with loss of the mucus – producing glands.
• It is usually associated with atrophic rhinitis and pharyngitis caused by klebsiella ozaenae.
• The most common sites involved in larynx are the false cords (vestibular folds), the posterior region and the subglottic region.
• More common in women.

Clinical features

• Irritable cough and hoarseness
• Excessive crusts formation which are sometimes bloodstained (hemorrhagic) with foul odour. Crusts are the most important diagnostic feature.

Treatment

• Elimination of causative factors and humidification.
• Laryngeal sprays with glucose in glycerine or oil of pine helps in crust removal. Expectorants containing ammonium chloride or iodides also help to loosen the crust.
• Microlaryngoscopic removal of crust in laryngitis sicca is the new modality of treatment.