Salmonella strain in US pigs linked to resistant group from Europe
A new study published in Clinical infectious Diseases suggests that a Salmonella strain circulating in pigs in the US Midwest is part of an emerging clade from Europe that is resistant to multiple antibiotics and may pose a public health risk.
The strain, Salmonella 4,,12:i:-, causes many foodborne disease outbreaks mostly tied to pigs and pork products and is expanding in the United States, according to the report by researchers from Minnesota and the United Kingdom.
The team used whole-genome sequencing to assess the relatedness of 659 S 4,,12:i:- isolates and 325 S Typhimurium isolates from various sources and locations in the United States and Europe. They also searched for resistance genes and other virulence factors and, for 50 livestock isolates and 22 human isolates, determined the antimicrobial resistance phenotypes.
The researchers found that the S 4,,12:i:- isolates fell into two main clades, regardless of their host or place of origin. Eighty-four percent of the US isolates recovered from 2014 through 2016, including nearly all those from pigs in the Midwest, were part of an emerging clade. This clade carried multiple genetic markers for antimicrobial resistance, including resistance to ampicillin, streptomycin, sulphonamides, and tetracyclines.
In addition, phenotypic (actual) resistance to enrofloxacin and ceftiofur was found in 11 of the 50 tested livestock isolates and 9 of the 22 human isolates. This was accompanied by plasmid-mediated resistance genes.
The authors conclude that S 4,,12:i:- strains circulating in Midwestern swine herds "are likely part of an emerging multidrug resistant clade first reported in Europe, and can carry plasmid-mediated resistance genes that may be transmitted horizontally to other bacteria and thus could represent a public-health concern."
Oct 23 Clin Infect Dis abstract
CDC awards $9 million more for research to slow antibiotic resistance
The US Centers for Disease Control and Prevention (CDC) today announced $9 million in awards to support research into new ways to combat antibiotic resistance and to identify knowledge gaps related to the problem. The support will go to 25 centers, including several major universities and other institutions, such as the Children's Hospital of Philadelphia and the J. Craig Venter Institute.
In its announcement, the CDC said the awards are part of its Antibiotic Resistance Solutions Initiative, intended to grow innovative approaches to fighting antibiotic resistance. In fiscal years 2016 and 2017 the initiative awarded more than $24 million.
The CDC said in a press release e-mailed to journalists that the latest round of awards is targeted to discovering and testing new strategies to protect patients from resistance threats in healthcare settings, investigate the threat from the human microbiome, and probe the impact of antibiotic resistance elements—genetic material that can move between and combine with bacteria—from environmental sources such as surface water and soil.
Newly funded projects are detailed in a list on the CDC's website.
Oct 23 CDC announcement