Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans
Korean researchers report MCR-1, MCR-3 in E coli from food animals
South Korean researchers have confirmed the colistin-resistance genes MCR-1 and MCR-3 in Escherichia coli isolates from food animals, according to a study yesterday in the International Journal of Infectious Diseases.
The scientists analyzed 636 E coli isolates collected from 2014 through 2017, 9 of which proved to be resistant to colistin, an antibiotic of last resort used to treat drug-resistant infections, as well as resistant to other antimicrobials. Of the 9 isolates, 3 harbored MCR-1 genes and 2 harbored MCR-3. All of the MCR-1 and MCR-3 genes proved to be transferable to another E coli strain, the authors said.
This is the first known report of MCR-3 in healthy animals in South Korea, the authors say.
Since MCR-1 was first discovered in E coli isolates in China in 2015, the gene has been detected in animals, humans, and the environment in more than 30 countries. Scientists have identified MCR-1 through MCR-7 in E coli and other bacterial species, including Klebsiella and Enterobacter.
May 24 Int J Infect Dis abstract
Scottish stewardship program helps reduce use of powerful antibiotics
Originally published by CIDRAP News May 24
A paper today in the Journal of Antimicrobial Chemotherapy reports that a Scottish stewardship program resulted in decreasing use of carbapenems and piperacillin/tazobactam and could be generalized to other antibiotics.
In response to rising use of the antibiotics in Scottish hospitals, the Scottish Antimicrobial Prescribing Group (SAPG) introduced guidance in 2013 that emphasized optimizing the use of carbapenems and piperacillin/tazobactam in patients with multidrug-resistant gram-negative bacteria infections and considering the use of carbapenem-sparing antibiotics. Using an online survey, researchers with SAPG aimed to evaluate how the guidance had been implemented by local health boards and translated into clinical practice. They also conducted a point prevalence survey (PPS) to evaluate prescribing and analyzed national prescribing data to assess the impact of the guidance.
The results of the survey showed that meropenem was subject to restrictions in 13 boards (87%), while piperacillin/tazobactam was restricted in 7 boards (47%), with an infection specialist authorizing use. In addition, compliance with local guidelines was good for meropenem but lower for piperacillin/tazobactam. The PPS data showed that carbapenem use was less than 2% of all antibiotics in all boards, while piperacillin/tazobactam use varied from 1% to more than 6%. Over the course of a 2-year improvement program that involved two interventions (introduction of the guidance and a subsequent quality improvement program), use of carbapenems and piperacillin/tazobactam decreased.
"Comparison with other countries suggests that Scotland is 'bucking the trend' of stable or increasing rates of carbapenem and piperacillin/tazobactam use," the authors write. "We consider this three-part improvement project will be of interest to stewardship colleagues as it can be applied to other antimicrobials to investigate and inform safe and effective clinical practice."
May 26 J Antimicrob Chemother abstract
Hypervirulent XDR Klebsiella pneumoniae strain identified in Taiwan
Originally published by CIDRAP News May 24
In another study today in the Journal of Antimicrobial Chemotherapy, scientists in Taiwan report the identification of a strain of extensively drug-resistant (XDR), carbapenemase-producing, and hypervirulent Klebsiella pneumoniae.
For the study, researchers analyzed K pneumoniae carbapenemase (KPC)-producing K pneumoniaeisolates from clinical specimens collected at Taipei Veterans General Hospital from January 2012 through December 2014. They investigated the isolates for capsular types and the presence of the virulence genes rmpA and rmpA2, and conducted molecular and genomic testing to identify sequence types and resistance elements.
A total of 62 KPC-2-producing K pneumoniae strains were identified, all of which belonged to sequence type ST11 and capsular genotype K47. But an additional strain, isolated from a fatal case with intra-abdominal abscess, was found to harbor rmpA and rmpA2 and did not belong to the major cluster associated with the other KPC-2-producing strains. In addition to carbapenems, the strain was also resistant to tigecycline and colistin, which has not been previously reported in carbapenem-resistant hypervirulent K pneumoniae strains. The strain exhibited high in vivo virulence in a mouse infection model.
Whole-genome sequencing identified two plasmids containing KPC-2 and several other antibiotic resistance genes, along with a novel hybrid plasmid harboring rmpA/rmpA2 and additional virulence genes not found in the classic ST11 KPC-2-producing strains.
The convergence of hypervirulence and carbapenem resistance in K pneumoniae is considered a significant health threat. In August 2017, Chinese researchers reported an outbreak of ST11 hypervirulent carbapenem-resistant K pneumoniae at a Chinese hospital where all five patients died.
"Active surveillance focusing on both the antimicrobial resistance and virulence characteristics of K pneumoniae strains is necessary, as the threat to human health is imminent," the authors write. "Further studies regarding carbapenem-resistant hypervirulent K pneumoniae worldwide to explore the evolutionary relationship between virulence and resistance in K pneumoniae are encouraged."
May 24 J Antimicrob Chemother abstract
Groups urge McDonald's to cut antibiotics from beef supply
Originally published by CIDRAP News May 24
A coalition of advocacy groups today called on McDonald's to do more to address antibiotic resistance.
In an event held outside McDonald's headquarters in Chicago during the company's annual shareholder meeting, representatives from U.S. PIRG Education Fund, Consumer's Union, Food Animal Concerns Trust, and CREDO Action delivered 160,000 petition signatures from consumers urging the company to eliminate beef raised with antibiotics from its supply chain. The fast-food giant stopped selling chicken raised with medically important antibiotics in 2016 and has laid out a vision for phasing out antibiotics in beef and pork, but has not made any specific commitments.
According to estimates, approximately 70% of all medically important antibiotics sold in the United States are used in poultry and livestock production. Although medically important antibiotics can no longer be used for growth promotion, they are still routinely used for disease prevention. Infectious disease and public health experts are concerned that this practice contributes to antibiotic resistance.
"We must end the routine use of antibiotics in animals in order to preserve these drugs for curing human disease," Jean Halloran of Consumer's Union said in a press release from U.S. PIRG. "McDonald's is in a unique position to lead the industry by prohibiting antibiotic use in the production of its burgers."
McDonald's is the largest beef purchaser in the United States.
May 24 U.S. PIRG press release
NDM, MCR-1 resistance genes found in same E coli isolates in China
Originally published in CIDRAP News May 23
Chinese scientists yesterday reported on the emergence of extensively drug-resistant (XDR) E coli carrying both New Delhi metallo-beta-lactamase (NDM) and MCR-1 genes in chickens at slaughter in China and detailed the features of two novel NDM-carrying plasmids.
In a letter in the Journal of Antimicrobial Chemotherapy, the investigators said they collected 50 fecal samples from chickens at a slaughterhouse in Qingdao, which sits on the Yellow Sea in eastern China. They recovered 33 E coli isolates from the samples.
Two of the strains showed resistance to imipenem and had an XDR pattern. Polymerase chain reaction and Sanger sequencing confirmed that the strains harbored both NDM and MCR-1. In one isolate the resistance genes were located on separate plasmids, while on the other the NDM gene was on a plasmid and the MRC-1 gene was on a chromosome. Plasmids are mobile pieces of DNA that can transfer to other bacteria of either the same or different species.
NDM-1 was first detected in 2008 and confers resistance to a broad range of beta-lactam antibiotics, including carbapenems. MCR-1 was first identified in China in 2015 and confers resistance to colistin, an antibiotic of last resort. So the detection of both of them in the same bacterium warrants increased concern over XDR pathogens that may be untreatable.
In addition, the scientists write, "To the best of our knowledge, this study identified for the first time the presence of blaNDM-1 gene in phage-like IncY plasmid, which has been associated with mcr-1 and blaVIM-1. Although phage-like plasmid is non-conjugative, it can be integrated into conjugative plasmids via recombination." They also note that one MCR-1 was found on an IncI2 plasmid that was almost 99% identical to a plasmid belonging to IncK2, which has been tied to the spread of MCR-1 in E coli in Europe.
May 22 J Antimicrob Chemother letter
Study find sharps containers pose no risk of C difficile infection
Originally published in CIDRAP News May 23
A microbiological investigation published yesterday in the American Journal of Infection Control has found the containers used to safely dispose of needles and other sharp medical instruments pose no risk of Clostridium difficile infection (CDI).
The investigation was following up on a 2015 study that found that a significantly lower rate of CDI in hospitals that used disposable sharps containers (DSCs) over those using reusable sharps containers (RSCs), but did not propose a scientific explanation for how the containers might spread CDI to patients. The hypothesis was that the statistical association found in the previous study was an artifact and that DSCs and RSCs may have a low spore burden but no fomite potential.
The study was conducted in three stages. In the first, 197 RSCs were swabbed for the presence of C difficile before processing. In the second stage, RSCs were challenged with high C difficile densities to evaluate the decontamination process. In the third stage, the investigators sampled 50 DSCs and 50 RSCs in CDI patients' rooms in seven hospitals to determine whether they differed in their carriage rate of C difficile spores. The investigators combined this evidence with epidemiologic studies, clinical requirements, and chain-of-infection principles.
The results showed that C difficile spores were found on 9 of 197 (4.6%) RSCs prior to processing, but that processing completely removed all spores. In CDI patient rooms, the C difficile carriage rate was 8% with RSCs and 16% with DSCs, but the investigators found an insufficient number of spores on either type of container to constitute an infective dose. In addition, because sharps containers are no-touch and healthcare workers must remove gloves after sharps disposal, a mode of transmission to the patient is impossible.
"In examining epidemiologic, microbiologic, chain-of-infection and test-of-evidence criteria, we could find no scientific evidence or mechanism whereby sharps containers could be implicated in CDI transmission," the authors write.
May 22 Am J Infect Control study
UK government, Gates Foundation join CARB-X's drug resistance efforts
Originally published by CIDRAP News May 22
The UK government and the Bill & Melinda Gates Foundation have joined the CARB-X partnership to support scientific research to develop new antibiotics, vaccines, diagnostics, and other measures against drug-resistant bacterial infections, CARB-X said in a news release today.
The UK's Global Antimicrobial Resistance Innovation Fund is committing up to £20 million ($26.9 million), and the Bill & Melinda Gates Foundation up to $25 million to CARB-X over the next 3 years. CARB-X (Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator) is the world's largest public-private partnership promoting research and development to combat the antimicrobial resistance crisis.
Combined with existing funding commitments from Wellcome Trust and the US government, CARB-X now has more than $500 million to invest in antibacterial development. CARB-X has so far invested in 33 projects from seven countries.
Dame Sally Davies, England's chief medical officer said, "We must work together to tackle this problem, and that is why I’m delighted the UK Government and the Bill and Melinda Gates foundation are joining the CARB-X partnership. Through CARB-X, the UK Government’s Global AMR Innovation Fund will be supporting research into the development of new vaccines and other life-saving products to tackle drug-resistant infections in developing countries where the burden is greatest."
The expanded CARB-X partnership was announced at the launch of the Global Antimicrobial Resistance R&D Hub during the 71st World Health Assembly meeting this week in Geneva.
May 22 CARB-X news release
Study finds links between kids antibiotic use and acute gastroenteritis
Originally published by CIDRAP News May 21
A new study in the Journal of the Pediatric Infectious Diseases Society has found an association between previous antibiotic use in children and increased odds of acute gastroenteritis.
The study analyzed 1,142 inpatient and outpatient children with acute gastroenteritis (AGE) treated at Vanderbilt University Medical Center from December 2014 through November 2015 and compared them to a control group of 394 healthy children. Multiple logistic regression was performed to evaluate the association between previous antibiotic use and four outcomes: overall AGE, norovirus-associated AGE, rotavirus-associated AGE, and nonnorovirus/nonrotavirus AGE.
The reported antibiotic use rates in the 3 months before illness onset were similar across all four outcome groups (overall AGE, 21%; norovirus-associated AGE, 23%; rotavirus-associated AGE, 28%, and nonnorovirus/nonrotavirus AGE, 22%) and higher than among the healthy controls (9%). After controlling for age, sex, and household income, the researchers found that the odds of antibiotic use in the 3 months before illness onset were 2.6 times higher for children with AGE overall than for healthy controls. In addition, children with AGE were 4.6 times more likely to have reported antibiotic use in the 3 weeks before illness onset. Similar results were found for the other specific AGE outcomes.
The authors of the study say the findings suggest a link between AGE, antibiotic use, and disruption of the intestinal microbiota, and provide further justification for judicious use of antibiotics in children.
"These data suggest that the intestinal microbiota might play a role in overall protection against AGE among children, even AGE caused by a virus, because disruption of this microbiota through antibiotic use increases the odds of AGE," they write.
May 19 J Pediatric Infect Dis study