Stewardship / Resistance Scan for Nov 27, 2019

News brief

Scientists develop genotype-phenotype rapid susceptibility test

Scientists from Harvard University and the Massachusetts Institute of Technology report that a diagnostic test they developed allows simultaneous detection of genotype and phenotype, enabling rapid and accurate antibiotic susceptibility determination in under 4 hours, according to their findings detailed in a letter in Nature Medicine.

The authors note that growth-based tests are constrained by the speed at which bacteria reproduce, and genotypic assays are limited by the ever-growing diversity and complexity of antibiotic resistance mechanisms in bacteria. So they developed an antibiotic susceptibility test (AST) that detects both genotype and phenotype of microbes to enhance speed and accuracy.

Their test, GoPhAST-R (combined genotypic and phenotypic AST through RNA detection—pronounced "go faster") can detect a pathogen's genotype and phenotype in a single rapid assay that simultaneously generates data on resistance prediction and molecular epidemiology. The test detects specific messenger RNA expression signatures in bacteria after they are briefly exposed to antibiotics. The scientists validated the test using three common antibiotic classes— luoroquinolones, aminoglycosides and carbapenems—in five pathogens that have a propensity for multidrug resistance.

They determined an accuracy of 94% to 99% within 4 hours using blood samples and note that their approach yields phenotype information 24 to 36 hours faster than other tests.

The authors conclude, "GoPhAST-R has the potential for even faster phenotypic AST on timescales that can inform early antibiotic decisions and thus transform infectious disease practice."
Nov 25 Nat Med letter

 

Study finds lower rates of drug-resistant bacteria in omnivores

Just in time for the US Thanksgiving tradition of carnivorous feasting, Dutch researchers report that vegetarians and pescatarians (vegetarians who eat fish) have higher rates of carriage of antibiotic-resistant Enterobacteriaceae than non-vegetarians do, indicating that eating meat is not an important risk factor in harboring certain types of superbugs.

The findings appeared this week in the Journal of Antimicrobial Chemotherapy.

Given that extended-spectrum beta-lactamase (ESBL)– and plasmid-mediated AmpC (pAmpC)–producing Enterobacteriaceae are common on Dutch meat products, the investigators sought to determine whether vegetarians are at a lower risk of carrying ESBL/pAmpC-producing Escherichia coli or Klebsiella pneumoniae (ESBL-E/K) compared with people who eat meat. Their analysis included 785 vegetarians, 392 pescatarians, and 365 non-vegetarians.

Fecal sampling determined that 8.0% of vegetarians (95% confidence interval [CI] and 6.3%-10.1%), 6.9% of pescatarians (95% CI, 4.8%-9.8%) carried ESBL-E/K microbes—compared with only 3.8% of non-vegetarians (95% CI, 2.3%-6.3%).
Nov 25 J Antimicrob Chemother abstract

 

Phase 3 trial shows good results for fidaxomicin against C difficile in kids

The narrow-spectrum antibiotic fidaxomicin has shown good efficacy against Clostridioides difficile infection (CDI) in adults. Now, in a phase 3 trial published today in Clinical Infectious Diseases, the drug outperformed vancomycin against CDI in children and adolescents.

The trial, dubbed the SUNSHINE study, enrolled 142 children ages 0 to 17 years who had CDI diagnosed according to clinical criteria and diagnostic testing in one of 39 sites in the United States, Canada, or Europe. Thirty of the patients were younger than 2 years old. Patients were randomized 2:1 to 10 days of treatment with either twice-daily oral fidaxomicin or four-times-daily oral vancomycin.

The researchers reported a clinical response rate (no evidence of CDI) of 77.6% (76/98) in the fidaxomicin group and 70.5% (31/44) in the vancomycin group. Global cure (clinical response plus no CDI recurrence) was noted in 68.4% of fidaxomicin patients and 50.0% of vancomycin patients. Adverse events were noted in 73.5% of fidaxomicin patients, compared with 75.0% in the other group.

The data reflect similar findings of a previous phase 3 trial in adults.

An accompanying commentary by Larry Kociolek, MD, of Northwestern University, noted, "The SUNSHINE trial is a major step forward in addressing the need for evidence-based CDI treatment options in children. However, to continue to move the needle for C. difficile research in children, a deeper understanding of the pathogenesis, clinical microbiology, and immunology of CDI in children is needed."
Nov 27 Clin Infect Dis study
Nov 27 Clin Infect Dis commentary

News Scan for Nov 27, 2019

News brief

CDC: 27 more people sickened with E coli in romaine outbreak 

The Centers for Disease Control and Prevention (CDC) said yesterday that 27 more people have been sickened in an Escherichia coli outbreak tied to romaine lettuce grown near Salinas, California. The outbreak total now stands at 67 people in 19 states, with 3 states reporting their first cases. 

"CDC advises that consumers not eat and retailers not sell any romaine lettuce grown in the Salinas, California, growing region. This includes all use-by dates and brands of romaine lettuce from this region," the agency said. Most romaine lettuce is labeled with a growing region, but if a growing region is not provided, the CDC recommends not eating the lettuce.

Thirty-nine people have been hospitalized because of their illnesses, including six case-patients who have developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.

Wisconsin has reported the most cases, with 21, followed by Ohio (12). Maryland and California each have reported four cases.
Nov 26 CDC update

 

Blackberries from Fresh Thyme markets implicated in hepatitis A outbreak 

The Food and Drug Administration (FDA) announced yesterday that a multistate outbreak of hepatitis A is potentially linked to conventional (non-organic) blackberries from Fresh Thyme Farmers Market grocery stores.

"Based on the epidemiological information collected in the investigation thus far, ill patients reported consuming fresh conventional blackberries from Fresh Thyme Farmers Market stores in five states: Indiana, Michigan, Minnesota, Nebraska, and Wisconsin," the FDA said in a statement.

Fourteen people have fallen ill in those five states, according to a CDC update last week, with the most recent illness onset reported as Nov 15. Eight people have been hospitalized, and there have been no deaths. The FDA warned that Fresh Thyme stores in 11 states—Iowa, Illinois, Indiana, Kentucky, Michigan, Missouri, Minnesota, Nebraska, Ohio, Pennsylvania, and Wisconsin—sold possibly contaminated berries.

The FDA is urging consumers in those states to toss any Fresh Thyme blackberries bought between Sep 9 and Sep 30. If consumers in those 11 states have eaten the conventional blackberries in the past 2 weeks, the FDA suggests they talk to a healthcare provider about obtaining post-exposure prophylaxis for hepatitis A.
Nov 26 FDA
statement
Nov 20 CDC update

 

Global measles count tops 440,000 cases 

The World Health Organization (WHO) today released new information about the global reach of measles in 2019, and said so far this year member nations have reported 440,263 measles cases.

The Democratic Republic of the Congo has been hit especially hard, with an 250,270 suspected cases and 5,110 associated deaths. Guinea, Chad, Madagascar, and Nigeria are also experiencing large outbreaks. 

In the WHO's European region, which includes parts of Asia, Ukraine has reported the most cases, with 56,802 cases, followed by Kazakhstan with 10,126 cases and Georgia with 3,904 cases. The Ukrainian outbreak has been tied to cases in the United States this year.

Elsewhere, outbreaks in Brazil, Bangladesh, and the Philippines also drove up global case counts. 

"Even with implementation of routine immunization, measles continues to circulate globally due to suboptimal vaccination coverage and population immunity gaps. Any community with less than 95% population immunity is at risk for an outbreak," the WHO said. Many of the nations facing outbreaks have conducted ongoing vaccination campaigns with the measles, mumps, and rubella vaccine.

According to WHO data, there were 408,225 confirmed measles cases worldwide at the same time in 2018.
Nov 27 WHO measles
update
WHO measles and rubella
surveillance data 

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