Scottish stewardship program helps reduce use of powerful antibiotics

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

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 pneumoniae isolates 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

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 US 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