Prevalence and Characteristics of Ceftriaxone-Resistant Salmonella in Children’s Hospital in Hangzhou, China

Abstract

The non-Typhi Salmonella (NTS) infection is critical to children’s health, and the ceftriaxone is the important empirical treatment choice. With the increase resistance rate of ceftriaxone in Salmonella, the molecular epidemiology and resistance mechanism of ceftriaxone-resistant Salmonella needs to be studied. From July 2019 to July 2020, a total of 205 NTS isolates were collected, 195 of which (95.1%) were cultured from stool, but 10 isolates were isolated from an extraintestinal site. Serogroup B accounted for the vast majority (137/205) among the isolates. Fifty-three isolates were resistant to ceftriaxone, and 50 were isolated from children younger than 4years of age. The resistance rates for ceftriaxone, ciprofloxacin, and levofloxacin were significantly higher in younger children than the older children. The resistance genes in the ceftriaxone-susceptible isolates were detected by PCR, and ceftriaxone-resistant Salmonella were selected for further whole-genome sequencing. Whole-genome analysis showed that serotype Typhimurium and its monophasic variant was the most prevalent in ceftriaxone-resistant isolates (37/53), which comprised ST34 (33/53), ST19 (2/53), and ST99 (2/53), and they were close related in the phylogenetic tree. However, the other isolates were diverse, which included one Enteritidis (ST11), one Indiana (ST17), one Derby (ST40), four Kentucky (ST198), two Goldcoast (ST2529, ST358), one Muenster (ST321), one Virchow (ST359), one Rissen (ST469), one Kedougou (ST1543), two Uganda (ST684), and one Kottbus (ST8839). Moreover, CTX-M-55 ESBLs production (33/53) was found to be mainly responsible for ceftriaxone resistance, followed by blaCTX-M-65 (12/53), blaCTX-M-14 (4/53), blaCTX-M-9 (2/53), blaCTX-M-64 (1/53), blaCTX-M-130 (1/53), and blaCMY-2 (1/53). ISEcp1, IS903B, IS Kpn26, IS1F, and IS26 were connected to antimicrobial resistance genes transfer. In conclusion, the dissemination of ESBL-producing Salmonella isolates resulted in an increased prevalence of ceftriaxone resistance in young children. The high rate of multidrug resistance should be given additional attention.

Characterization of Salmonella spp. in a tertiary hospital during 2019-2021 in Nanjing, China: Focusing on the clonal dissemination of Salmonella Enteritidis ST11

“…Fortunately, the observed frequencies of resistance to monocyclic β-lactam antibiotics (aztreonam) and third and fourth generation cephalosporins were lower when compared to data from other studies [27,29,31]. Luckily, the distribution of MDR strains in our study was lower than reports in Argentina [30], Iran [37], Philippine [38], USA [33,39], and parts of China [31,35], indicating that the third-and fourth-carbapenems could be still effective for the clinical therapy of Salmonella infections.…”

“…The reason may lie on the regional or strain difference. Meanwhile, our study showed that the resistance rates to cipro oxacin and levo oxacin were relatively lower than those in China [27,35], but it was higher when compared to data from Korea [34], USA [33], and Australia [36], suggesting the potential for treatment failure in patients treated with uoroquinolones in our country. Fortunately, the observed frequencies of resistance to monocyclic β-lactam antibiotics (aztreonam) and third and fourth generation cephalosporins were lower when compared to data from other studies [27,29,31].…”

Plasmid Composition, Antimicrobial Resistance and Virulence Genes Profiles of Ciprofloxacin- and Third-Generation Cephalosporin-Resistant Foodborne Salmonella enterica Isolates from Russia

“…Resistance to ceftriaxone is most commonly mediated by a cephalomycinase (CMY) encoded by the bla CMY gene family [ 52 ]. The susceptibility test in the current report confirmed the resistance of all the isolates studied to CRO.…”

The Genetic Characteristics and Carbapenem Resistance Mechanism of ST307 Klebsiella pneumoniae Coharbouring blaCMY-6, blaOXA-48, and a Truncated blaNDM-1

“…The genomic DNA of all the isolates was extracted by a QIAamp DNA Mini Kit (QIAGEN, Hilden, Germany) and subjected to whole-genome sequencing on the Illumina HiSeq xTen platform (Illumina, San Diego, CA, USA) with a 150 bp paired-end strategy, as previously described [ 25 ]. Isolates CHN24001 and CHN24025 were further subjected to long-read sequencing by a MinION sequencer device (Nanopore Technologies, Oxford, UK) with a 1D flow cell.…”

“…cgMLST was performed by Ridom seqsphere (version 6.0.0, Ridom GmbH, Münster, Germany), as previously described [ 31 ]. The randomly selected 92 isolates from different continents along with the 5 isolates in this study were imported for phylogenetic relationship analysis based on their single-nucleotide polymorphisms (SNPs) using Snippy [ 25 ]. The genome of C234 was used as a reference (accession number: SAMN15868954) [ 9 ], and the tree was illustrated by iTol ( (accessed on 22 August 2022)).…”