Sequence Analyses and Phenotypic Characterization Revealed Multidrug Resistant Gene Insertions in the Genomic Region Encompassing Phase 2 Flagellin Encoding fljAB Genes in Monophasic Variant Salmonella enterica Serovar 4,5,12:i:- Isolates From Various Sources in Thailand
serovar 4,5,12:i:- ( . 4,5,12:i:-), a monophasic variant of Typhimurium (STm) lacking the phase 2 flagellin encoding genes , has become increasingly prevalent worldwide. The increasing trends in multidrug resistant (MDR) . 4,5,12:i:- prevalence also pose an important global health threat. Though man...
Saved in:
Published in | Frontiers in microbiology Vol. 12; p. 720604 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
Frontiers Media S.A
04.10.2021
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | serovar 4,5,12:i:- (
. 4,5,12:i:-), a monophasic variant of
Typhimurium (STm) lacking the phase 2 flagellin encoding genes
, has become increasingly prevalent worldwide. The increasing trends in multidrug resistant (MDR)
. 4,5,12:i:- prevalence also pose an important global health threat. Though many reports have characterized phenotypic and genotypic drug resistance of this serovar, few studies have characterized antimicrobial resistance of this serovar in Thailand. In this study, 108
. 4,5,12:i:- isolates from various sources in Thailand and four international
. 4,5,12:i:- isolates were screened using polymerase chain reaction (PCR) to detect the presence of five target regions which are associated with antimicrobial resistant (AMR) genes, in the genomic region that contained
genes in STm. We determined AMR phenotypes of all isolates by Kirby-Bauer disk diffusion method. Whole genome sequencing (WGS) was performed on 53 representative isolates (based on differences in the pulsed filed gel electrophoresis profiles, the sources of isolate, and the PCR and AMR patterns) to characterize the genetic basis of AMR phenotype and to identify the location of AMR determinants. Based on PCR screening, nine PCR profiles showing distinct deletion patterns of the five target regions have been observed. Approximately 76% of isolates (or 85 of 112 isolates), all of which were Thai isolates, contained five target regions inserted between STM2759 and
gene. A total of 21 phenotypic AMR patterns were identified with the predominant AmpST resistant phenotype [i.e., 84% (or 94 of 112) tested positive for resistance to ampicillin, streptomycin, and tetracycline], and 89% (or 100 of 112) were found to be MDR (defined here as resistant to at least three classes of tested antimicrobials). Using WGS data, a total of 24 genotypic AMR determinants belonging to seven different antimicrobial groups were found. AMR determinants (i.e.,
,
,
, and
, conferring resistance to ampicillin, streptomycin, sulfonamides, and tetracycline, respectively) were found to be inserted in a region typically occupied by the phase 2 flagellin encoding genes in STm. These resistant genes were flanked by a number of insertion sequences (IS), and co-localized with mercury tolerance genes. Our findings identify AMR genes, possibly associated with multiple IS
copies, in the genetic region between STM2759 and
genes replacing phase 2 flagellin encoding
genes in Thai
. 4,5,12:i:- isolates. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 This article was submitted to Food Microbiology, a section of the journal Frontiers in Microbiology Edited by: Arun K. Bhunia, Purdue University, United States Reviewed by: Graciela Volz Lopes, Federal University of Pelotas, Brazil; Min Yue, Zhejiang University, China Present address: Aye Thida Win, Department of Microbiology, University of Medicine, Magway, Myanmar |
ISSN: | 1664-302X 1664-302X |
DOI: | 10.3389/fmicb.2021.720604 |