Jockey Club School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Konggrid.10784.3a, Hong Kong Special Administrative Region.
Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Konggrid.10784.3a, Prince of Wales Hospital, Hong Kong Special Administrative Region.
Microbiol Spectr. 2021 Sep 3;9(1):e0024821. doi: 10.1128/Spectrum.00248-21. Epub 2021 Aug 4.
Nontyphoidal Salmonella (NTS) gastroenteritis in children remains a significant burden on health care and constitutes a majority of all admissions for Salmonella infections in public hospitals in Hong Kong. In this prospective study, 41% of 241 children hospitalized with gastroenteritis from three public hospitals during 2019 were culture confirmed to have NTS infection. These Salmonella isolates were whole-genome sequenced and predicted for their serovars/serotypes using the Salmonella Typing Resource (SISTR) and SeqSero1, and the antimicrobial resistance (AMR) genes were determined. Phylogenetic analysis revealed three major clades belonging to Salmonella enterica serovar Enteritidis sequence type 11 (ST11) (43%), multidrug-resistant (MDR) Typhimurium ST19 (12%) and its monophasic variant ST34 (25%), and mostly singletons of 15 other serovars. MDR Typhimurium and its variant were more common in infants <24 months of age and possessed genotypic resistance to five antimicrobial agents, including ampicillin (A), chloramphenicol (C), aminoglycosides (Am), sulfonamides (Su), and tetracyclines (T). Older children were more often infected with Enteritidis, which possessed distinct genotypic resistance to AAmSu and fluoroquinolones. In addition, 3% of the isolates possessed extended-spectrum beta-lactamase (ESBL) CTX-M genes, while one isolate (1%) harboring the carbapenemase gene was identified. Our findings provide a more complete genomic epidemiological insight into NTS causing gastroenteritis and identify a wider spectrum of determinants of resistance to third-generation beta-lactams and carbapenems, which are often not readily recognized. With high rates of multidrug-resistant NTS from studies in the Asia-Pacific region, the rapid and reliable determination of serovars and resistance determinants using whole-genome sequencing (WGS) is invaluable for enhancing public health interventions for infection prevention and control. Nontyphoidal Salmonella (NTS) gastroenteritis is a foodborne disease with a large global burden. Antimicrobial resistance (AMR) among foodborne pathogens is an important public health concern, and multidrug-resistant (MDR) Salmonella is prevalent in Southeast Asia and China. Using whole-genome sequencing, this study highlights the relationship of the MDR Salmonella serotypes and the diverse range of Salmonella genotypes that contaminate our food sources and contribute to disease in this locality. The findings update our understanding of Salmonella epidemiology and associated MDR determinants to enhance the tracking of foodborne pathogens for public health and food safety.
非伤寒沙门氏菌（NTS）肠炎仍然是儿童健康的重大负担，也是香港公立医院沙门氏菌感染住院治疗的主要原因。在这项前瞻性研究中，2019 年三家公立医院因肠炎住院的 241 名儿童中，有 41%经培养证实感染了 NTS。对这些沙门氏菌分离株进行全基因组测序，并使用沙门氏菌分型资源（SISTR）和 SeqSero1 预测其血清型/血清型，同时确定抗生素耐药性（AMR）基因。系统发育分析显示，属于肠炎沙门氏菌血清型 11（ST11）的三个主要分支（43%）、多药耐药（MDR）鼠伤寒沙门氏菌 ST19（12%）及其单相变体 ST34（25%），以及其他 15 个血清型的大多数单克隆。MDR 鼠伤寒沙门氏菌及其变体在<24 个月龄的婴儿中更为常见，对包括氨苄西林（A）、氯霉素（C）、氨基糖苷类（Am）、磺胺类（Su）和四环素（T）在内的五种抗菌药物具有基因型耐药性。年龄较大的儿童更常感染肠炎沙门氏菌，该菌对 AAmSu 和氟喹诺酮类药物具有独特的基因型耐药性。此外，3%的分离株携带扩展谱β-内酰胺酶（ESBL）CTX-M 基因，而鉴定出 1%的分离株携带碳青霉烯酶基因。我们的研究结果提供了对引起肠炎的 NTS 的更完整的基因组流行病学见解，并确定了对第三代β-内酰胺类药物和碳青霉烯类药物耐药性的更广泛决定因素，这些决定因素通常不易识别。鉴于亚太地区研究中存在高比例的多重耐药 NTS，使用全基因组测序（WGS）快速可靠地确定血清型和耐药决定因素对于加强感染预防和控制的公共卫生干预措施至关重要。非伤寒沙门氏菌（NTS）肠炎是一种食源性疾病，在全球范围内造成了巨大的负担。食源性病原体的抗生素耐药性（AMR）是一个重要的公共卫生问题，多药耐药（MDR）沙门氏菌在东南亚和中国很普遍。本研究使用全基因组测序，强调了 MDR 沙门氏菌血清型与污染我们食物来源并导致当地疾病的各种沙门氏菌基因型之间的关系。研究结果更新了我们对沙门氏菌流行病学和相关 MDR 决定因素的认识，以加强对食源性病原体的跟踪，从而促进公共卫生和食品安全。
