Trends in Isolation and Antimicrobial Susceptibility of Enteropathogenic Bacteria in 2011-2019 at a Korean Tertiary Care Hospital Compared with Data in the Preceding Reports

Vandarith Nov1 , Le Phuong Nguyen2,3 , Kennedy Mensah Osei1 , Hyukmin Lee3 , Dongeun Yong3 , Kyungwon Lee3

1Department of Global Health Security, Yonsei University Graduate school of Public Health, Seoul
2Brain Korea 21€plus Program€for Medical Science, Yonsei University College of Medicine, Seoul
3Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea

Corresponding author : deyong@yuhs.ac

ABSTRACT

Background: Environmental sanitation plays a significant role on the prevalence of enteropathogenic bacteria. This study aimed to determine the trends in the prevalence and antimicrobial resistance profiles of enteropathogenic bacteria from 2011 to 2019.
Methods: A retrospective analysis was performed using data from stool cultures of Salmonella spp., Shigella spp., Plesiomonas shigelloides, Yersinia spp., Vibrio spp., and Campylobacter spp. Samples were obtained between 2011 and 2019 from Severance Hospital. Antimicrobial susceptibility profile was determined using the disk diffusion method for nontyphoidal Salmonella (NTS) and Campylobacter spp., following the Clinical and Laboratory Standards Institute (CLSI) guidelines.
Results: The number of specimens obtained for stool culture increased significantly from 13,412 during the period of 1969­1978, to 48,476 over the past nine years (2011­2019), whereas the ratio of positive specimens decreased significantly from 1,732 (12.9%) to 449 (0.9%). The proportion of samples positive for Salmonella Typhi decreased from 472 (93.6%, 1969­1978) to 4 (1.5%, 2011­2019), whereas the proportion of NTS increased from 14 (2.8%, 1969­1978) to 261 (96.7%, 2011­2019). Among all the enteropathogenic bacteria isolated, Shigella spp. accounted for 60.0% (1,039) isolates from 1969 to 1978, but only 1.6% (7) from 2011 to 2019. Campylobacter was the second most prevalent enteropathogenic bacteria, accounting for 29.4% isolates (132). Among the NTS strains isolated from 2016 to 2019, their susceptibility rates to ampicillin and sulfamethoxazole-trimethoprim were 51.1% and 85.2%, respectively. Additionally, the susceptibility rate of Campylobacter to ciprofloxacin was 15.8%.
Conclusion: The prevalence of Salmonella Typhi and Shigella spp. significantly decreased, whereas those of NTS and Campylobacter spp. increased. Therefore, continuous monitoring of ciprofloxacin-resistant Campylobacter spp. is of vital importance.

Keywords

Campylobacter species, Enteropathogenic bacteria, Salmonella species

Figures & Tables

 

Table 1. Comparison of trends in isolation of enteropathogenic bacteriaa t a tertiary-care hospital

Characteristic

Period of data acquisition*

1969-1978

1979-1988

1989-1998

2001-2010

2011-2019

No. of specimen cultured

13,412

37,846

51,441

60,714

48,476

No. of positive specimen

1,732

3,503

2,140

648

449

% of positive specimen

12.9

9.2

4.2

1.1

0.9

No. of positive patient

1,677

3,182

1,531

565

449

Salmonella Typhi

472

469

58

1

4

Salmonella Paratyphi A

18

101

3

2

0

Salmonella serogroup B

3

245

564

86

111

Salmonella serogroup C

4

108

126

89

82

Salmonella serogroup D

5

107

341

157

63

Salmonella serogroup E

2

32

55

22

5

Salmonella other serogroup

0

40

39

2

5

All Salmonella isolates

504

1,102

1,186

359

270

Shigella subgroup A

16

5

2

0

0

Shigella subgroup B

781

1,246

30

3

1

Shigella subgroup C

8

43

0

0

6

Shigella subgroup D

234

214

19

95

0

All Shigella isolates

1,039

1,508

51

98

7

Campylobacter spp.

NT

185

239

85

132

Yersinia enterocolitica

NT

29

18

1

1

Vibrio parahaemolyticus

45

96

42

27

7

Plesiomonas shigelloides

NT

4

11

0

0

*The data from 1969-2010 were adapted from reference [7].
Abbreviation: NT, not tested.