Prevalence and Genetic Analysis of mcr-3-Positive Aeromonas Species from Humans, Retail Meat, and Environmental Water Samples.

The mobile colistin resistance gene mcr-3 is globally disseminated in both Enterobacteriaceae and Aeromonas species, with the latter potentially serving as a reservoir for this gene. Here, we investigated the prevalence of mcr-3 in rectal swabs from humans, in food-producing animals and their products, and in the aquatic environment, and we investigated the genetic relationships between the mcr-3-positive isolates. An enriched broth screening method was used to detect mcr-3 in samples, and species identification of isolates from positive samples was carried out by matrix-assisted laser desorption ionization-time of flight mass spectrometry and shotgun sequencing. All mcr-3-positive isolates were subjected to antimicrobial susceptibility testing, conjugation, and whole-genome sequencing. Ten Aeromonas isolates, including 2 from human rectal swabs, 1 from pork, 3 from chicken meat, and 4 from the aquatic environment, were positive for mcr-3, but only 2 showed resistance to colistin. In addition to the mcr-3 variants identified previously (the novel variants were termed mcr-3.13 to mcr-3.18), all isolates harbored mcr-3-like genes downstream of the mcr-3 variants. The MCR-3.13 to MCR-3.18 proteins exhibited only 89.2% to 96.1% amino acid identity to the original MCR-3 protein. Whole-genome sequence analysis indicated diversity within the genetic environments of mcr-3-positive Aeromonas isolates and possible transmission between different sources in China and even worldwide. Close relationships between mcr-3-positive and mcr-3-negative Aeromonas isolates suggested that mcr-3 might be common in Aeromonas species, which are not inherent hosts of mcr-3 but may act as an important reservoir of this mobile colistin resistance gene.

mcr-1 in Enterobacteriaceae from Companion Animals, Beijing, China, 2012-2016.

To investigate the prevalence of the recently emerging colistin resistance gene mcr-1 in Enterobacteriaceae among companion animals, we examined 566 isolates collected from cats and dogs in Beijing, China, during 2012-2016. Of these isolates, 49 (8.7%) were mcr-1-positive.

Research on Influencing Factors and Dimensions of Health Literacy in Different Age Groups: Before and After the COVID-19 Era in Chongqing, China.

Background: Understanding the levels of health literacy among different groups is essential for better public health interventions targeting specific subgroups of the population. Additionally, this article explores the prevalence and influencing factors of the health literacy levels of different age groups during the COVID-19 epidemic. Methods: Multistage stratified cluster random sampling and the Probability Proportion to Size (PPS) method were used to select permanent residents aged 15-69 in Chongqing (54,706) for the questionnaire survey. The survey period is from July 2019 and July 2020. Single-factor analysis and logistic regression models were used to study the relationship between demographics, socioeconomic factors, other independent covariates, and health literacy. Results: The health literacy levels of residents declined with age, and there were significant differences in health literacy levels between age groups (χ2 = 3332.884, P < 0.05). As far as the factors affecting health literacy level are concerned, high education and high income are the protective factors for health literacy level for residents of all ages. For adolescents (OR = 1.383, 95% CI: 1.217-1.571), young adults (OR = 1.232, 95% CI = 1.117-1.358), and middle-aged people (OR = 1.096, 95% CI = 1.017-1.182), residence in rural areas was a protective factor. In terms of the dimensions of health literacy, in particular, elderly health literacy in 2020 in Scientific Health Concepts, Safety and First Aid, Basic Medical Care decreased significantly compared with 2019. Conclusions: For adolescents, young adults, middle-aged people, to solve the problem of urban and rural health quality gap, we should not only use the geographical division, but also consider the social population and socio-economic differences. For the elderly, the following four dimensions of health literacy need to be paid more attention than those of other age: Basic Knowledge and Concepts, Scientific Health Concepts, Safety and First Aid, and Basic Medical Care. A lack of knowledge on the prevention and treatment of chronic diseases is the main reason for the recent decline in health literacy. And the health literacy among residents in major public health emergencies is needed.

Co-existence of two novel phosphoethanolamine transferase gene variants in Aeromonas jandaei from retail fish.

Two novel phosphoethanolamine transferase genes, eptAv7 and eptAv3, were identified in the chromosome of an Aeromonas jandaei isolate from retail fish. The variants showed 79.9% and 80.0% amino acid identity to MCR-7.1 and MCR-3.1, respectively, and increased colistin resistance 128- to 256-fold in Aeromonas salmonicida. The two variants with no mobile genetic element in the flanking regions were also observed in other Aeromonas species. This finding supports the view that Aeromonas is a reservoir for MCR-3 and MCR-7 mobile colistin resistance.

Integrated aquaculture contributes to the transfer of mcr-1 between animals and humans via the aquaculture supply chain.

BACKGROUND: Since its discovery in 2015, the mobile colistin resistance gene mcr-1 has been reported in bacteria from >50 countries. Although aquaculture-associated bacteria may act as a significant reservoir for colistin resistance, systematic investigations of mcr-1 in the aquaculture supply chain are scarce. OBJECTIVES: We investigated the presence of colistin resistance determinants in the aquaculture supply chain in south China and determined their characteristics and relationships. METHODS: A total of 250 samples were collected from a duck-fish integrated fishery, slaughter house, and market in Guangdong Province, China, in July 2017. Colistin-resistant bacteria were isolated on colistin-supplemented CHROMagar Orientation plates, and the species were identified by matrix-assisted laser desorption/ionization time-of-flight assay. The presence of mcr genes was confirmed by polymerase chain reaction analysis. We examined the minimum inhibitory concentrations (MICs) of 16 antimicrobial agents against the isolates using agar diffusion and broth microdilution methods. Whole-genome sequencing (WGS) was used to explore the molecular characteristics and relationships of mcr-1-positive Escherichia coli (MCRPEC). RESULTS: Overall, 143 (57.2%) colistin-resistant bacteria were isolated, of which, 56 (22.4%, including 54 Escherichia coli and two Klebsiella pneumoniae) and four Aeromonas species were positive for mcr-1 and mcr-3, respectively. The animal-derived MCRPEC were significantly more prevalent in integrated fishery samples (40.0%) than those in market (4.8%, P<0.01) samples but not in slaughter house (28.0%, P=0.164). All MCRPEC were highly resistant to ampicillin, tetracycline, and compound sulfamethoxazole (>90%) but were susceptible to carbapenems and tigecycline. WGS analysis suggested that mcr-1 was mainly contained on plasmids, including IncHI2 (29.6%), IncI2 (27.8%), IncX4 (14.8%), and IncP (11.1%). Genomic analysis suggested mcr-1 transmission via the aquatic food chain. CONCLUSIONS: MCRPEC were highly prevalent in the aquaculture supply chain, with the isolates showing resistance to most antibiotics. The data suggested mcr-1 could be transferred to humans via the aquatic food chain. Taking the "One Health" perspective, aquaculture should be incorporated into systematic surveillance programs with animal, human, and environmental monitoring.

Anthropogenic and environmental factors associated with high incidence of mcr-1 carriage in humans across China.

MCR-1-positve Escherichia coli (MCRPEC) have been reported in humans worldwide; however, thus far, their prevalence is low and potential sources for human mcr-1 carriage have not yet been identified. Here, we analyse a nationwide epidemiological dataset on MCRPEC in humans throughout China and assess the factors associated with MCRPEC carriage using natural and national anthropogenic data. We identified 774 non-duplicate MCRPEC isolates from 774 stool samples collected from 5,159 healthy individuals in 30 provinces and municipalities in 2016, with a prevalence of MCRPEC ranging from 3.7 to 32.7% (average: 15.0%)-substantially higher than previously reported. MCRPEC carriage was associated with provincial regions, the production of sheep and freshwater aquaculture, annual consumption of total meat, pork and mutton, and daily intake of aquaculture products. MCRPEC was significantly more prevalent in provinces with higher aquaculture industries. Whole-genome sequencing analysis revealed that the MCRPEC isolates were clustered into four distinct lineages, two of which were dominant and harboured most of the MCRPEC isolates. The high prevalence of MCRPEC in the community poses a substantial risk for colistin usage in clinical practice and suggests the need for intestinal screening of mcr-1 carriers in intensive care units in Chinese hospitals. Furthermore, our data suggest that aquaculture is a significant reservoir of mcr-1.