Background Image
Table of Contents Table of Contents
Previous Page  6 / 32 Next Page
Information
Show Menu
Previous Page 6 / 32 Next Page
Page Background

International Journal of Human Nutrition and Functional Medicine

www.IntJHumNutrFunctMed.Org

2014 Final PDF

Table 1. Results of Stool analysis Conducted by Subject Laboratory—

continued

Sample

ID

Organism

Added to

Normal Stool

Specimen

Quantity

Normal Stool

Flora

Opportunistic

Bacteria

Pathogenic

Bacteria

Yeast/ Fungi Parasites

29

E. coli 0157:H7

5.6x106 CFU/g

+

-

-

-

No Ova or

Parasites

30

Vibrio

parahemolyticus

9.2x102 CFU/g

+

-

-

-

Parasite

Present;

taxonomy

unavailable

31

Vibrio

parahemolyticus

9.2x105 CFU/g

+

6.1 X 107

Klebsiella

pneumoniae

-

-

Parasite

Present;

taxonomy

unavailable

32

Clostridium

difficile

5.4x102 CFU/g

+

-

-

-

No Ova or

Parasites

33

Clostridium

difficile

5.4x105 CFU/g

+

-

-

-

No Ova or

Parasites

34

Normal Stool

Flora

N/A

+

-

-

-

No Ova or

Parasites

35

E. coli 0157:H7

5.6x103 CFU/g

+

-

-

-

Parasite

Present;

taxonomy

unavailable

36

E. coli 0157:H7

5.6x106 CFU/g

+

-

-

-

No Ova or

Parasites

37

Vibrio

parahemolyticus

9.2x102 CFU/g

+

-

-

-

Parasite

Present;

taxonomy

unavailable

38

Vibrio

parahemolyticus

9.2x105 CFU/g

+

6.1 X 107

Klebsiella

pneumoniae

-

-

Parasite

Present;

taxonomy

unavailable

39

Clostridium

difficile

5.4x102 CFU/g

+

-

-

-

No Ova or

Parasites

Discussion

There is a growing demand for faster results for

microbiology testing and a growing demand for

molecular based analyses that promise results on

demand. However, molecular based testing for stool

pathogens is still under development and there are

currently no FDA cleared

in vitro

assay commercially

available. In this study we challenged the claims of a

CLIA licensed laboratory that offers a novel DNA

method for identifying microorganisms in human stool

samples. Our survey showed that the subject laboratory

was unable to identify any of the ten enteric pathogens

added to a normal stool specimen even though the

quantities of microorganisms added were at levels above

the stated threshold of detection for the novel assay.

Furthermore, the subject laboratory reported “parasites

present” in 50% of the samples tested even though no

parasites were added to the survey samples and an equal

number of the same stool sample were reported negative

for parasites.

Other investigators have reported the successful

application of molecular methods for detection of

microorganisms from human gastrointestinal samples.

Real-time PCR has been successfully applied for

quantification of bacterial DNA in feces (2,9,15,19),

colonic tissue (4), rumen (18), gastric tissue (5) and

periodontal samples (1). Rinttilä and colleagues

designed an extensive set of real-time PCR assays

targeting a large group of predominant and pathogenic

human gut microbial species. They demonstrated that

real-time PCR using SYBR Green I chemistry has an

advantage of being a very sensitive and precise

technique for an extensive quantitative evaluation of the

gut microbiota and is also feasible for detection of

human pathogens from fecal samples. Using fecal

samples spiked with various amounts of target bacteria

they demonstrated detection limits could be obtained

that were between 6 × 10

3

(

H. pylori

) and 6 × 10

4

(

Clostridium difficile

and

Campylobacter jejuni

) cells

per gram of feces (16). In a subsequent publication,

Rinttilä et al. used quantitative real-time PCR (qPCR)

panel to detect 12 pathogenic microorganisms from

fecal samples of irritable bowel syndrome subjects (17).

Some laboratories have developed in-house