primate assay data sheet
(including virulence factors magA and rmpA)
B0060 - Qualitative ultrasensitive detection of
pneumoniae bacteria by real time polymerase chain reaction.
This assay detects and
differentiates a genomic target and two
virulence factors, magA
Klebsiella pneumoniae bacteria belong to the family
Enterobacteriaceae. These organisms are nonmotile, rod-shaped,
gram-negative bacteria with a prominent polysaccharide capsule.
This capsule encases the entire cell surface and gives the
bacterium a large appearance on gram stain; it also
imparts resistance against many host
Members of the
Klebsiella genus typically express 2 types of antigens on their cell
surface. One is a lipopolysaccharide
(O antigen); the other is a capsular polysaccharide (K antigen).
Both of these antigens contribute to pathogenicity of the
bacteria in this genus. Approximately
9 O antigens
and 77 K antigens exist. The structural
variability of these antigens forms the basis for classification
of the bacteria into various serotypes. Nevertheless, there are
no specific correlations of the various serotypes with
Klebsiella pneumoniae, the
Klebsiella genus also contains
Klebsiella oxytoca, Klebsiella planticola,
Klebsiella terrigena, and
All these bacteria have very similar
homology. K pneumoniae
is the most medically important species of the group, but
K. oxytoca and K.
rhinoscleromatis have also been found in human clinical
can be found in the environment and have widespread occurrence.
In humans, they may colonize the skin, pharynx or
gastrointestinal tract. They may also colonize sterile wounds
and urine. Many animals and humans are asymptomatic carriers.
Klebsiellae may even
be regarded as normal flora in parts of
the colon, intestinal tract and
biliary tract. Oropharyngeal carriage has been associated with
endotracheal intubation, impaired host defenses, and
K. pneumoniae produces large, sticky colonies on an agar plate. Some
strains of K. pneumoniae
possess a “hypermucoviscosity” phenotype; this phenotype is
related to higher pathogenicity. The expression of this
hypermucoviscosity phenotype is determined by the presence of
several genes, including magA (mucoviscosity-associated gene A)
and rmpA (regulator of the mucoid phenotype A). The
hypermucoviscosity phenotype of K. pneumoniae
can be classified as
capsular serotypes K1 or K2.
K1 serotypes of K. pneumoniae have rmpA and
magA. K2 serotypes of K. pneumoniae have
rmpA but not magA. Studies have shown that while magA presents
exclusively in the K1 capsular serotype, rmpA can be detected in
either K1 or K2 capsular serotypes and also in approximately
two-thirds of non-K1/K2 capsular serotypes. Capsular
serotypes K1 and K2
are reported to play an important role in the
invasive ability of K. pneumoniae
(Yeh et al., 2007). In some studies, the presence of magA
is linked to liver abscess formation (Fang et al., 2004).
detection of K. pneumoniae is of limited value because the
method cannot reliably differentiate pathogenic strains from
bacteria present as normal flora in the body. Although
hypermucoviscosity can be assessed by a “string test,” the test
is highly subjective and can lead to false results. Furthermore,
culture identification cannot definitively identify the presence of magA and
rmpA which are important in determining pathogenic potential of
the bacteria. Molecular detection not only provides rapid,
sensitive and specific identification of the bacteria, but can
also accurately determine the presence of these virulence
Help confirm the disease causing agent
Shorten the time required to confirm a clinical
diagnosis of Klebsiella
Help ensure colonies are free of
Differentiate virulent from non-virulent
Identify magA and rmpA virulence factors in
Early prevention of spread of these bacteria among a
Minimize human exposure to these bacteria
Safety monitoring of biological products and vaccines
that derive from primates
Fang, C.T., Chuang, Y.P., Shun, C.T., Chang, S.C. and Wang, J.T.
(2004) A novel virulence gene in
strains causing primary liver abscess and septic metastatic
complications. J. Exp. Med. 199:697–705.
Yeh, K.M., Kurup, A., Siu, L.K., Koh, Y.L., Fung, C.P., Lin, J.C., Chen,
T.L., Chang, F.Y. and Koh, T.H.(2007) Capsular serotype K1 or
K2, rather than magA and rmpA, is a major virulence determinant
for Klebsiella pneumoniae liver abscess in Singapore and Taiwan. J Clin
- Rectal swab, or oral swab, or 0.2 ml feces, or 0.2 ml bacterial culture.
- 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
types other than those listed here, please call to confirm
specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
3 business days
real time PCR