1

อุ�บั�ติ�การณ์�ขอุงเชื้��อุ Streptococcus suis

ในเลื�อุดสุ�กรด�บัที่��วางจำ�าหน�ายในติลืาดเขติกร�งเที่พมหานคร

นายที่รงกร�ชื้ หน$นารถ4612110047

น.สุ.ม�ที่น� เอุกพณ์�ชื้ก�จำ4612110048

นายวสุ�นติ� กฤติกรธนา4712110084

2

Contamination of Streptococcus suis

in food for human consumptions

3

Significance

• Bacterial contamination in food is one of major Thai public health problems.

• Concerns of WHO

• Increase in incidence of S. suis infection among human consumers.

• Health personnels are paying much more attention and awaring for the correct diagnosis.

4

Streptococcus suis Infection

• People closely contact with live pigs or raw pork products, slaughterer, butcher (Rusmeechan, 2008)

• Improperly cooked pork or products from pigs (Tramontana, 2008; Lee, 2008)

• Other routes (Rusmeechan, 2008)

• Household rearing and slaughtering (Yu, 2006)

5

Thailand Vietnam

ChinaJapan

Australia

USA

6

Streptococcus suis

• Gram’s positive cocci or coccobacilli

• Paired or filamentous

• Facultative anaerobe

• Produces capsules

• Able to hemolyze red blood cells

• Lancefield group R (Facklam, 2002)

7

Clinical signs

• Sepsis

• Purulent meningitis

• Arthritis

• Deafness from meningogenic labyrinthitis (Madsen, 2001)

• Death

8

Objectives

• A survey of the contamination of S. suis in raw pig blood selling in Bangkok metropolitan’s fresh market

• A collection of information to raise a concern to protect consumers in Bangkok and vincinity areas

9

Procedures

• Randomly selected samples of raw pig blood in fresh market by using two-stage random sampling technique

• Randomly chosen 3 Bangkok’s districts for this study namely Huai-Kwang, Bangkapi, and Ladkrabang

• Collected 12 samples from each district without bias of hygiene and cleanliness

10

Culture and Purification

• Luria-Bertani broth at 37°C for 18-24 hrs.

• Sheep blood agar at 37°C for 18-24 hrs (Hardie, 1986)

11

Identification

• Colony characteristics

• α-Hemolysis

• Gram-positive cocci or coccobacilli

• Biochemical tests

• S. suis type II CCUG 7984 DMST 18783 as positive control (DMSC)

12

S. suis type II

13

DMSC recommended biochemical tests

• pin-point to small size

• cocci and coccobacilli

• sheep blood agar

• catalase –ve

• oxidase -ve

14

Carbohydrate Fermentation Tests

• glucose +ve• sorbitol –ve• mannitol –ve• lactose +ve• innulin +ve• raffinose +ve

• sucrose +ve• amygdalin -ve • melibiose -ve • trehalose +ve • esculin +ve

15

16

Results

Criteria Number of Sample

Colony Characteristics 34

Morphology 27

Gram’s stain 16

α-Hemolysis 3

Biochemical tests 0

17

Discussion

• Methods using for this study were modified from Bergey’s Manual of Determinative Bacteriology (Holt, 1994) and from DMSC protocol for S. suis Identification.

• Markets randomly selected from 3 districts of Bangkok were the representatives of sources where consumers could easily access and be effected from bacterial contamination in food materials.

18

Discussion

• S. suis could live in the environment for several hours, therefore, if bacteria are truly persisted in pig products, the tests could have proven (Higgins, 2006).

• The study could not find the bacteria from raw pig blood but did not prove that there were absolutely no bacterial contamination.

19

Discussion

• The biochemical tests could not certainly identified S. suis from other Streptococci.

• There are 35 serotypes of S. suis to be identified but by using molecular techniques.

20

Discussion

• No trace of S. suis to be found in pig blood could be the consequence of good food hygiene policy and regulations.

• Otherwise, the number of samples taken may be too small to include the incidence of contamination.

21

Discussion

• Major factors associated with the infections from other areas of Thailand are close contact with pigs and home rearing and slaughtering of pigs unlawfully, for instance.

• API Strep system test could not clearly identified S. suis from other Streptococci because of variation of biochemical tests.

22

Discussion

• Avoiding consumption of improperly cooked food with ingredients from pigs.

• Practicing good hygiene if experiencing contact with live pigs or raw pork products.

• Further studies are needed to identify other factors involved in bacterial growth and survival such as the preservatives usage or other sampling collected from abattoir.

23

Acknowledgement

• รศ.ดร.นวลฉว� เวชประสิ�ทธิ์�� ภาคว�ชาเทคโนโลยี�ช�วภาพ คณะว�ทยีาศาสิตร� มหาว�ทยีาล�ยีรามค�าแหง

• นางสิ"รางค� เดชศ�ร�เล�ศห�วหน#าฝ่%ายีแบคท�เร�ยีท�'วไป และ น.สิ.ป)ต�มน พลว�ช�ยี ฝ่%ายีแบคท�เร�ยีท�'วไป สิถาบ�นว�จั�ยีว�ทยีาศาสิตร�สิาธิ์ารณสิ"ข กรมว�ทยีาศาสิตร�การแพทยี� กระทรวงสิาธิ์ารณสิ"ข

• นพ.กฤษดา ศ�รามพ"ช ผู้1#อำ�านวยีการสิถาบ�นเวชศาสิตร�อำายี"รว�ฒน�นานาชาต�

24

Thank you very much!