Nguyen Do Phuc Institute of Public Health in Ho Chi Minh (IPH)

25 August, 2016

The Project for Determining the Outbreak Mechanisms and Development of a Surveillance Model for Multi-Drug Resistance Bacteria

Prevalence of extended-spectrum-β-lactamase-producing Escherichia coli in foods in Vietnam

- Extended-spectrum β-lactamase (ESBL) -producing E. coli poses a threat to public health care because of its ability to hydrolyze 3rd-generation cephalosporins.

- ESBL-producing E. coli have been rapidly expanding worldwide to date.

- Recently, several studies showed the significantly high prevalence of ESBL-producing E. coli in healthy individuales in Southeast Asia: China (65.0%), Thailand (58.2-69.3%) and Vietnam (51.0%), and that in healthy travelers from Netherlands to East and South Asia (67%, 72%, respectively). possibility of the potential transmission of ESBL producing E. coli from food-producing animal to human via Food chain (FC).

- However, the extent to which animal-based food contribute to a dissemination route for these bacteria to human in the FC has not yet been investgated in Southeast Asia.

Introduction

- Determine the prevalence of ESBL-producing E. coli in chicken meat, pork, and fish/shrimp samples obtained in the food distribution system in Vietnam.

Research purposes

Specific Goals

1. Prevalence of ESBL-producing E. coli 2. Genetic characterization of ESBL-producing E. coli 3. ESBL phenotyping and Antibiotic resistance of ESBL-producing E. coli isolates

Method for Isolation of ESBL-E.coli in food

BPW

(225 g)

CHROMagar ECC

with 1 µg/ml CTX

TSI, LIM, CLIG,

TSA, Stock (-30oC)

Day 1 Day 2 Day 3 Day 4

Sample 25 g +

TSI:Triple Sugar Iron agar slants LIM: Lysine Indole Motility medium CLIG: Cellobiose Lactose Indole 𝛽-Glucuronidase agar slnts

Bacteria incubated at

35oC/20h on TSA Treak bacteria suspension on surface of MH

Let the dried surface 15’

Read results

Place the antibiotic disks

Dilution bacteria the same 0,5Mc Farland

incubation

Disk diffusion method (CLSI method)

CTX CAZ

CAZ CLA

CTX CLA

ESBL (+): differnce of zone diameter ≥ 5 mm between CTX/CLA and CTX or CAZ/CLA and CAZ AmpC (+): R (Cefocitine)

ESBL genes:

TEM (372bp), SHV (231bp), CTX-M-1 (588bp), CTX-M-2

(107bp), CTX-M-8 (186bp), CTX-M-9 (475bp).

Multiplex-PCR for detection ESBL genes

Results

42.0%

76.1%

40.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Pork Chicken Fish/Shrimp

Prevalence of ESBL-E. coli in Foods in Vietnam

1. Prevalence of ESBL-producing E. coli

Fig 1a: The prevalence of ESBL-E.coli between food matrixs

Prevalence of ESBL-producing E. coli in food in some countries

Fig 1b: The prevalence of ESBL-E.coli in some countries

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Chicken Pork Fish Shrimp

70.4%

83.3%

27.8%

50.7%

88.3%

68.5%

32.0%

58.7%

18.3%

34.8%

92.7%

29.3%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Pork Chicken Fish/Shrimp

Hanoi Thai Binh

Nha Trang Ho Chi Minh

Fig 1b: The prevalence of ESBL-E.coli between sites in Viet Nam

62

50

47

44

70

30

3 6 1

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

HCM ThaiBinh

NhaTrang

Chicken

CTX-M-1 CTX-M-9

CTX-M-1/CTX-M-9 TEM

SHV TEM/SHV

15

35 18

41

42 25

1 2

3

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

HCM ThaiBinh

NhaTrang

Pork

CTX-M-1 CTX-M-9

CTX-M-1/CTX-M-9 TEM

SHV TEM/SHV

15

48

7

13

106

4

2 7

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

HCM ThaiBinh

NhaTrang

Fish/Shrimp

CTX-M-1 CTX-M-9

CTX-M-1/CTX-M-9 TEM

SHV TEM/SHV

Fig. 2 Distribution of ß-lactamase genes in ESBL-producing E. coli isolates in food in Vietnam

2. Genetic Characterization of ESBL-producing E. coli

Results of ESBL/pAmpC-producing E. coli

isolated from 150 of 330 food samples

corrected from HCM

Nguyen Do Phuc et al., 2016.

Dissemination of extended-spectrum ß-lactamase- and AmpC ß-lactamase-

producing Escherichia coli within the food distribution system of Ho Chi Minh

City, Vietnam.

Phylogenetic analysis showed that : - Group B1 (42.1–45.3%) was the most prevalent among isolates from chicken, pork, and beef, - whereas group A (52.3%) was predominant among isolates from fish/shrimp. - Phylogenetic group B1 was most frequently detected among all isolates ( 42.4%), followed by

groups A ( 36.0%) and D (19.9%). As expected, phylogenetic group B2 (1.8%) was detected at low frequency among isolates from all food types. Although the phylogenetic groups were not linked to definite CTX-M group or resistance patterns, 5 of the 6 isolates that belonged to clinically relevant B2 group were found to contain pAmpC genes

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Chicken Pork Beef Fish

D

B2

B1

A

Perc

enta

ge o

f E.

co

li is

ola

tes

29.2%

44.3%

24.3%

41.3%

45.3%

12.0%

39.5%

42.1%

18.4%

52.3%

29.5%

15.9%

n=185 n=75 n=38 n=44

Fig. 3 Phylogenetic group distribution of ESBL-producing E. coli isolates

from food (n=342) in HCM

Fig 4. Multidrug-resistance distribution among food isolates of ESBL- producing E. coli (n=342) in HCM

This study showed: 1. A high prevalence of ESBL-producing E. coli isolates among chicken, pork, and fish/shrimp samples collected within the food distribution system in VN. 2. These findings demonstrate that animal based food products in VN represent a major reservoir of ESBL-producing E. coli. 3. Multidrug-resistant E. coli isolates: resistant to at least 6 to 10 antibiotic agents

Conclusion

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