AUTHOR=Kang Ying , Yu Keyi , Huang Zhenzhou , Pang Bo , Liu Shengtian , Peng Tao , Li Ying , Wang Duochun 

TITLE=Prevalence and molecular characteristics of Shewanella infection in diarrhea patients in Beijing, China 2017–2019

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1293577

DOI=10.3389/fmicb.2024.1293577

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p><italic>Shewanella</italic> is an important opportunistic pathogen distributed in marine environments that has caused an increasing number of clinical infections. However, there are few reports on the distribution and characteristics of <italic>Shewanella</italic> in the diarrheal pathogen spectrum. In this study, we have systematically described the prevalence of <italic>Shewanella</italic> infections in diarrhea patients in Beijing, China 2017–2019, and genome characteristics and antimicrobial susceptibility of <italic>Shewanella</italic> isolates.</p></sec><sec><title>Methods</title><p>Stool samples were collected from diarrhea patients in a surveillance project from 2017 to 2019. <italic>Shewanella</italic> strains were isolated, and identified using VITEKR 2 COMPACT and MALDI-TOF MS. Average nucleotide identity (ANI) analysis, multi-locus sequence typing (MLST), phylogenetic analysis, virulence-associated genes and antimicrobial resistance genes analysis were used for genome characteristics description. The antibiotic susceptibility test was performed with microbroth dilution method.</p></sec><sec><title>Results</title><p>1104 fecal samples were collected, and the <italic>Shewanella</italic> detection rate was 2.36% (26/1104). The main manifestations of infection caused by <italic>Shewanella</italic> spp. were diarrhea (100%, 26/26), abdominal pain (65.38%, 17/26), and vomiting (38.46%, 10/26). The 26 isolates were classified into 3 species (<italic>S. algae</italic> (<italic>n</italic> = 18), <italic>S. indica</italic> (<italic>n</italic> = 5), and <italic>S. chilikensis</italic> (<italic>n</italic> = 3)) and 22 sequence types. Core genome single nucleotide polymorphism-based evolutionary tree identified three clone groups corresponding to three infection events in the same months in 2017 and 2019. The putative virulence-associated gene pool consisted of 56 potential virulence genes, including 19 virulence gene factors. The resistance rates of the 26 isolates to 17 antibiotics from high to low were as follows: polymyxin E (76.92%), cefotaxime (57.69%), ampicillin (50%), ampicillin-sulbactam (34.62%), nalidixic acid (15.38%), ciprofloxacin (11.54%), selectrin (3.846%,1/26), and tetracycline (3.846%, 1/26). The rate of multidrug resistance was 38.46% (10/26).</p></sec><sec><title>Discussion</title><p>Monitoring for <italic>Shewanella</italic> spp. should be added to the routine surveillance of infectious diarrhea during the epidemic season.</p></sec>