610. Inhibitory Activity of Fermented Milk with Lactobacillus casei Shirota (FMLC) against Common Mutidrug-Resistant (MDR) Bacteria Causing Hospital-Acquired Infections (HAI)
Session: Poster Abstract Session: Novel Antimicrobial Agents
Friday, October 21, 2011
Room: Poster Hall B1
Background:

Colonization and Infection with MDR bacteria, Acinetobacter baumannii (AB), Pseudomonas aeruginosa (PA), ESBL-producing Escherichia coli (EC) & Klebsiella pneumoniae (KP) and methicillin-resistant Staphylococcus aureus (MRSA), are common in hospitalized patients. Some probiotic products are found to be effective in treatment and prevention of several bacterial infections. The objectives of the study were to determine inhibitory activity of FMLC against common MDR bacteria causing HAI.                                                                            

Methods: 

Time-kill methods of FMLC and cell-free filtered fluid of FMLC (CF-FMLC) against AB, PA, EC, KP and MRSA were conducted. The control solutions were Mueller Hinton broth (MHB) and distilled water (DW). The mixtures of FMLC, CF-FMLC, MHB and DW with 106 CFU/ml of each bacterium were made and incubated at 35ºC. Each mixture was subcultured at 0, 1, 3, 6 and 24 h after incubation onto brain heart infusion agar plates. The inoculated agar plates were incubated at 35ºC for 24 h. Bacterial colonies on agar plates were counted and compared among the mixtures.  

Results: 

Log CFUs of each organism in MHB and DW after incubation were increased from 5.1- 6.3 at 0 h to 6.4 - >11 at 24 h. Log CFUs of each organism in FMLC and CF-FMLC after incubation for 0, 1, 3, 6 and 24 h are:

 

 

Colony count (Log CFU)

 

FMLC

CF-FMLC

 

0 h

1 h

3 h

6 h

24 h

0 h

1 h

3 h

6 h

24 h

AB

5.1

4.3

4.1

2

0

5.2

4.4

4.1

2.7

0

PA

5.3

4.7

3.3

 1

0

5.1

4.4

3.2

1

0

EC

5.1

4.6

3.9

3.1

0

5.1

4.5

3.7

2.8

0

KP

5.1

4.5

3.2

 1

0

5.1

4.8

3.1

1

0

MRSA

5.5

5.3

5.1

4.2

0

6.1

5.5

5.2

4.8

0

Conclusion: 

FMLC and CF-FMLC exerted slow inhibitory activity against MDR bacteria resulting in eradication of all tested organisms at 24 h. Such inhibitory effects were probably due to the product of the milk fermented by Lactobacillus casei Shirota. Clinical study is needed to determine if consumption of FMLC can prevent and treat colonization and infection with MDR bacteria in hospitalized patients.


Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Visanu Thamlikitkul, MD, Siriraj Hospital, Mahidol University, Bangkok, Thailand and Surapee Surapee Tiengrim, Siriraj Hospital, Bangkok, Thailand

Disclosures:

V. Thamlikitkul, None

S. Surapee Tiengrim, None

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