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Weekly Digest: Combination therapies may speed the development of drug resistance; Antibiotics commonly prescribed to patients without lab evidence in Sierra Leone; Rare resistance gene isolated from E. coli in US pets.

Weekly Digest: Combination therapies may speed the development of drug resistance; Antibiotics commonly prescribed to patients without lab evidence in Sierra Leone; Rare resistance gene isolated from E. coli in US pets.

Combination therapies may speed the development of drug resistance. Israeli researchers analyzed the evolution of Staphylococcus aureus strains in patients undergoing drug combination therapies and found that tolerance to a single antibiotic in the therapy may speed up the development of resistance to the second drug. Tolerance to an antibiotic, which causes it to kill bacteria slower than usual, is not of concern to many clinicians since most patients with tolerance will still be cured of their infections. In a Scientific American article that highlights this research, CDDEP director Ramanan Laxminarayan, who was not involved in the work, notes that the findings reveal a major threat to the way doctors currently think about combination antibiotics. [Science, Scientific American]

Antibiotics commonly prescribed to patients without lab evidence in Sierra Leone. A cross-sectional study co-authored by Eili Klein, a CDDEP Senior Fellow, identified high rates of antibiotic use without laboratory evidence among hospitalized adults in Sierra Leone. Of the 920 patients included in the study between 2017 and 2018, 81.8 percent had taken one or more antibiotics, although none of the patients received a bacterial culture. Surgical prophylaxis and pneumonia were common indicators for antibiotic prescribing, and cephalosporins, penicillins, and imidazoles were the most common classes of drugs prescribed. Findings suggest that investments are needed to improve antimicrobial stewardship within hospitals in low-income countries. [International Journal of Infectious Diseases]

Rare antibiotic resistance gene isolated from E. coli in US pets. A research letter published in Emerging Infectious Diseases reported the isolation of a rare antibiotic resistance gene, New Delhi metallo-β-lactamase-5 (NDM-5), from Escherichia coli in pets at a Philadelphia veterinary hospital. NDM-5 confers resistance to carbapenems, and the gene had previously never been detected among pets in the United States. It remains unknown how the bacteria isolated from the animals acquired this resistance gene. [Emerging Infectious Diseases]

Pan-resistant C. auris identified in three chronically ill New Yorkers. Researchers analyzed isolates from New York patients with Candida auris, a multidrug-resistant fungal infection, and identified three chronically ill individuals with pan-resistant isolates. The isolates were each resistant to the triazole, polyene, and echinocandins classes of antifungal medications. There is no evidence that transmission of the highly resistant C. auris occurred between patients and contacts, or to healthcare environments. [CDC MMWR]

Novel coronavirus reported in Thailand, Japan, and South Korea. Three new cases of the novel coronavirus (2019-nCoV) that originally infected a cluster of individuals in Wuhan, China have been reported in Thailand, Japan, and South Korea. All patients had recently traveled to Wuhan. The number of cases of the unexplained pneumonia-like illness has more than tripled in the past couple of days from 41 to 218 across China. There is not yet enough evidence to draw conclusions about the origin or transmissibility of the virus, but the World Health Organization urges countries to prepare for the spread of 2019-nCoV. [Wall Street JournalWHOThe Guardian]

Deadly strain of carbapenem-resistant Klebsiella emerges in China. Researchers identified a new dominant strain of carbapenem-resistant Klebsiella pneumoniae (CRKP)-causing bloodstream infections in China, which is deadlier and more virulent than other clones. The retrospective study analyzed 203 CRKP-causing bloodstream infections from 2013 to 2017, and identified a shift in the dominant strain from ST11-KL47 to ST11-KL64 in 2016. The emerging ST11-KL64 strain was associated with significantly higher 30-day mortality rates compared to ST11-KL47 (62.2 vs. 52.8 percent), and has shown enhanced environmental survival. [Emerging Infectious Diseases]

Experimental MERS drug shows success in mice. A team of researchers tested remdesivir, an experimental treatment for Middle East respiratory syndrome coronavirus (MERS-CoV), in mice and found promising results. Compared to a combination treatment for MERS that is currently being studied among humans in Saudi Arabia, remdesivir significantly improved lung function and reduced MERS-CoV viral load in the lungs. The study suggests that remdesivir may have the potential to treat MERS in humans. [Nature Communications]

Spike in dengue cases across Latin America linked to climate change. In 2019, close to 3 million cases of dengue fever were reported in Latin America, which is more than a 20 percent increase from the previous record-breaking year in 2015. Mosquito experts attribute this spike in dengue to abnormal rains, rising temperatures, and increasing humidity, which together create the optimal environment for mosquitoes to breed. [NPR Goats and Soda]

Pediatric ASPs linked to reduction in inappropriate prescriptionsIn a systematic review of 113 studies across the world, researchers in Italy found that a majority of pediatric antimicrobial stewardship programs (ASPs) significantly reduced inappropriate prescriptions in outpatient and in-hospital settings (79.6 percent). The study also linked pediatric ASPs to increased susceptibility of bacteria, lower rates of antimicrobial resistance, and increased healthcare cost savings, which were largely attributable to lower drug administration rates. [Antimicrobial Resistance and Infection Control]

Flu activity increases in the Northern Hemisphere. The World Health Organization’s global flu update has reported increasing rates of influenza across the temperate zone of the Northern Hemisphere. A majority of flu specimens worldwide (68.7 percent) were identified as influenza A, which is currently dominating in most of Europe and Asia. Influenza B, which accounts for one-third of global flu specimens this season, is currently the dominant strain in the United States and Canada. [WHO, CIDRAP]

Antibiotic use trends across the US, UK, and India. [CDDEP]