KLEBSIELLA

General characteristics of Klebsiella?

Gram-negative rod, 4 species, opportunistic pathogen, minor commensal in intestine

Primary animal pathogen of Klebsiella?

Klebsiella pneumoniae

Common sites of opportunistic infection in animals?

Reproductive tract (mares), mammary glands (bovine), urinary tract (bitches)

What are nosocomial infections caused by Klebsiella?

Hospital-acquired infections in humans and animals, easily spread, multiple antibiotic resistance

Other name of Klebsiella pneumoniae?

Friedlander’s Bacillus

Spore formation in Klebsiella?

No

Capsule formation in Klebsiella?

Yes, heavily capsulated

Flagella in Klebsiella?

No

Size of Klebsiella?

0.3–1.0 µm × 0.6–6.0 µm

Colony characteristics of Klebsiella?

Moist, spreading, glistening, highly viscid (mucoid)

Effect of carbohydrate-rich media on capsule?

Enhances capsule production

Is Klebsiella a facultative anaerobe?

Yes

Oxidase reaction of Klebsiella?

Negative

Tartrate utilization?

Positive

Malonate utilization?

Positive

H₂S production?

Negative

Urease production?

Positive

Methyl Red test?

Negative

Voges–Proskauer test?

Positive

Lactose fermentation?

Positive (partly plasmid encoded)

What are klebicins?

Bacteriocins produced by Klebsiella, used for typing strains

K antigen function?

Capsular antigen used for serologic typing

O antigen function?

Somatic antigen

Number of K antigen types?

At least 82

Number of O antigens?

11

Structure of K antigen?

Heat-stable polysaccharide composed of glucuronic acid and sugars like galactose, fucose, mannose, D-glucose, L-rhamnose

Reservoirs of Klebsiella?

Intestinal commensal and environment

Environmental sources of infection?

Wood shavings, timber products, source of mastitis in cattle

Common nosocomial infection sites?

Surgical wounds, urinary tract, bloodstream

Predisposing factor for nosocomial infections?

Use of antibiotics

Virulence feature of invasive Klebsiella strains?

Resist serum bactericidal factors, serum resistance associated with somatic antigens

Normal flora sites in mares?

Vestibule, urethra, clitoris

Opportunistic infections in mares?

Vaginal discharge, metritis, infertility, abortion

Transmission of Klebsiella in horses?

Stallion transmission, contaminated instruments, hands of handlers

Clinical signs of mastitis in cattle?

Hyperemia, edema, swelling of udder, reduced milk production, milk becomes serous fluid

Systemic signs of mastitis?

High fever initially, may subside, severe cases can develop fatal endotoxic shock

Other animal diseases caused by Klebsiella?

Sows: mastitis

Is protective immunity against Klebsiella well understood?

No, only serum-resistant strains are invasive

Antibody detection method?

Capsular swelling technique

Diagnosis of Klebsiella?

Microscopic examination (heavily encapsulated organisms), culture (mucoid colonies), uterine infection detection in mares (tampon method)

Antimicrobial resistance of Klebsiella?

Usually resistant to ampicillin and carbenicillin

Possible effective drugs?

Drugs effective against E. coli, e.g., cephalexin for canine urinary tract infections

Important note for treatment?

Sensitivity testing must always be performed