Stewardship / Resistance Scan for Aug 19, 2019

News brief

Carbapenem susceptibility test results widely variable, study finds

A study by Italian investigators in Clinical Microbiology and Infection has found that commercial methods for testing carbapenem susceptibility produced widely variable results in a sample of carbapenemase-producing Escherichia coli, with none satisfying the criteria for acceptable antimicrobial susceptibility testing (AST) performance.

In the study, the researchers tested a total of 54 non-replicate Klebsiella pneumoniae carbapenemase (KPC)-producing E coli isolates from two Italian hospitals for susceptibility to imipenem, meropenem, and ertapenem. They used the broth microdilution method (BMD) as a reference and several commercial testing systems (Vitek2, MicroScan, Etest, MIC Test Strip). Susceptibility to imipenem and meropenem was also tested by Sensititre and disk diffusion (Bio-Rad).

Results were interpreted according to EUCAST (European Committee on Antimicrobial Susceptibility Testing) clinical breakpoints. Essential agreement (EA), category agreement (CA), and error rates were calculated as described by the International Organization for Standardization (ISO) guidelines and also considering the new EUCAST definitions.

Reference BMD results showed that, of the 54 KPC-positive E. coli isolates, 5.6%, 7.4%, and 0% were susceptible to the standard dosing regimen, 55.6%, 72.2%, and 0% were susceptible to increased exposure, and 38.9%, 20.4%, and 100.0% were resistant to imipenem, meropenem and ertapenem, respectively. CA lower than 90% was observed with all systems for imipenem and meropenem, using both the ISO and the modified EUCAST criteria. With ertapenem, CA greater than 90% was observed with all methods except Vitek2. Overall, for commercial methods returning minimum inhibitory concentration (MIC) values and for all molecules, the EA with the reference method was relatively low, with no method being acceptable according to the ISO criteria.

"This study suggests that, whatever semiautomated AST systems are used for testing KPC-producing E. coli, laboratories should always confirm carbapenems MICs with reference BMD in order to carry out an appropriate antimicrobial therapy," the authors of the study conclude.
Aug 16 Clin Microbiol Infect study

New Australian AMR hub launched

The Australian Research Council (ARC) yesterday announced nearly $3.4 million in funding for a new antimicrobial resistance research center.

The ARC Research Hub to Combat Antimicrobial Resistance, which will focus on sexually transmitted microorganisms, aims to develop new technology to fight drug-resistant pathogens and guide investments in new antibiotics and diagnostics. The hub will bring together Australian universities, pharmaceutical and diagnostics companies, and healthcare partners and be led by Rebecca Guy, PhD, a professor of epidemiology the University of New South Wales.

"We plan to develop new molecular diagnostic technology and improve the processes for identifying potential new antibiotics," Guy said in a university press release. "The hub aims to connect the many complex facets of antimicrobial resistance, to provide a highly integrated diagnostic and pharmaceutical solution to the problem of antimicrobial resistance."

The ARC is contributing almost $5 million Australian ($3.4 million US) to the project. An additional $3.8 million Australian ($2.6 million US) is being provided by Australian-based biotech company SpeeDx and other industry partners.
Aug 18 ARC press release
Aug 19 University of New South Wales press release

News Scan for Aug 19, 2019

News brief

Multistate Cyclospora outbreak linked to imported basil sickens 73 more

A multistate Cyclospora outbreak linked to fresh basil imported from Mexico has sickened 73 more people, increasing the total to 205 infections, the Centers for Disease Control and Prevention (CDC) said in an Aug 15 update.

Though 11 states have reported related cases, all of the exposures occurred at restaurants in five states: Florida, Minnesota, New York, Ohio, and Wisconsin. Five people have been hospitalized, but no deaths have been reported. The latest illness onset was Jul 18.

Last month the CDC reported a steep rise in the number of domestic illnesses involving Cyclospora cayetanensis, a parasite that is spread by eating food and drinking water contaminated with feces. Infection can cause profuse diarrhea that can last weeks to months. The CDC said additional clusters are under investigation to determine if they are linked to the basil-related outbreak.

So far, product distribution records suggest Siga Logistics de LL de CV of Morelos, Mexico, exported the basil that sick people ate, and a trace-back investigation is ongoing to find the contamination source.

The Mexican importer recalled the potentially affected basil on Jul 24, according to the US Food and Drug Administration (FDA). The CDC has urged consumers who have fresh basil from the company in their homes not to eat it and to throw it away. It also advises importers, restaurants, and others to not sell, serve, or distribute the company's fresh basil.

Domestic and travel-associated Cyclospora cases typically arise in the summer. Outbreaks in the past have been linked to imported fresh produce such as raspberries, basil, cilantro, and snow peas.
Aug 15 CDC outbreak update
Aug 16 FDA update
Jul 26 CIDRAP News story "Multistate outbreak tied to basil part of Cyclospora surge"

China reports H5N6 avian flu infection in Beijing woman

China has reported a new H5N6 avian flu case, involving a 59-year-old woman from Beijing who is hospitalized in critical condition, according to a statement today from the Hong Kong Centre for Health Protection (CHP).

The woman was hospitalized on Aug 11, and the report did not say how she was exposed to the virus.

H5N6 has been identified in poultry outbreaks in China and a handful of other Asian nations, but China is the only country that has reported human cases, which are often severe or fatal.

With the new illness, China has now reported 24 cases. The country reported its last H5N6 infection in November, which involved a 10-year-old girl from the city of Suzhou in Jiangsu province.
Aug 19 CHP statement