US scientists report that they have produced a gene-edited calf with reduced susceptibility to bovine viral diarrhea virus (BVDV), an innovation they say could potentially reduce antimicrobial use in cattle.

In a proof-of-concept paper published yesterday in PNAS Nexus, a team led by scientists with the US Department of Agriculture (USDA) Agricultural Research Service describe how they used CRISPR gene-editing technology to produce a live calf with a six amino acid substitution in the BVDV binding domain of CD46, the main cellular receptor for BVDV. The scientists edited cattle skin cells to develop embryos carrying the altered gene, then transplanted the embryos into surrogate cows.

The calf, named Ginger, was born in July 2021, and after observation for several months was housed for a week with a BVDV-infected dairy calf to determine if she could become infected. Follow-up testing showed Ginger's cells displayed significantly reduced susceptibility to BVDV. The scientists say they will continue to monitor her health.

The most successful version of the future that I can see is one where we don't have to deal with antimicrobial resistance because we just don't use that many antimicrobials.

Although a BVDV vaccine has been available for more than 50 years, the disease remains common in cattle and can cause severe respiratory and intestinal harm to beef and dairy cattle. In addition, when pregnant cows are infected, BVDV can cross the placenta and infect developing calves, resulting in abortion, congenital malformation, or persistently infected cattle who constantly shed the virus and are at risk for secondary bacterial infections.

The authors of paper say that if the approach proves to be viable, it could improve animal welfare and reduce the cattle industry's reliance on antimicrobials.

"The most successful version of the future that I can see is one where we don't have to deal with antimicrobial resistance because we just don't use that many antimicrobials," paper co-author Brian Vander Ley, DVM, PhD, of the University of Nebraska-Lincoln, said in a university press release. "That's better for everyone. That means that we have eliminated the cause of a lot of the antimicrobial use and we've eliminated that expense for livestock producers."

A small randomized trial in patients with post-COVID syndrome has found that hyperbaric oxygen therapy (HBOT) promotes restoration of the heart's ability to contract properly, according to data presented today at EACVI 2023, a scientific congress of the European Society of Cardiology.

The study enrolled 60 patients in a randomized controlled double-blind trial that measured how and if HBOT helped patients who have mild to moderate long COVID. The therapy involves inhalation of 100% pure oxygen at high pressure, and has been shown to help non-healing wounds, radiation injury, and other types of infection by increasing oxygen delivery to damaged tissues.

All patients had five sessions per week over 8 weeks, for a total of 40 sessions. The HBOT group received 100% oxygen through a mask at a pressure of 2 atmospheres for 90 minutes, with 5-minute air breaks every 20 minutes. The control group breathed 21% oxygen by mask at 1 atmosphere for 90 minutes. Echocardiograms were done before the first session (baseline) and 1 to 3 weeks after the last session.

More research is needed to collect long-term results and determine the optimal number of sessions.

Echocardiography measured the heart's ability to contract and relax based on left ventricular global longitudinal strain (GLS). At baseline, nearly half of study participants (29 of 60; 48%) had reduced GLS. In healthy adults, GLS should be approximately -20%.

In the HBOT group, GLS significantly increased from -17.8% at baseline to -20.2% after the intervention. In the control group the GLS had no significant differences.

"The findings suggest that HBOT promotes recovery of cardiac function in patients with post-COVID syndrome," said Marina Leitman, MD, of the Sackler School of Medicine, Tel Aviv University and Shamir Medical Centre, Be'er Ya'akov, Israel. "More research is needed to collect long-term results and determine the optimal number of sessions for maximum therapeutic effect."

The Kentucky Department of Fish and Wildlife Resources (KDFW) this week said the state is seeking civil damages for the first time against a hunter for importing a diseased deer carcass.

The hunter from Louisville legally harvested the eight-point buck in Wisconsin, then brought the intact head into Kentucky for taxidermy, which violates Kentucky law in importing deer carcasses or other high-risk parts. The head contains lymph nodes, spinal column, and brain tissue, all of which are high-risk tissues.

So far, no deer or elk in Kentucky have tested positive for CWD, and KDFW said the head remained frozen during transport and storage.

Conservation officers followed up on information it received about the man's deer head, which had been frozen when it was inspected. Because it came from Wisconsin, which first documented CWD about two decades ago, officials ordered testing of tissues from the deer head, and two types of tests were positive for the disease.

We want to keep it from spreading to Kentucky's deer and elk herds.

The man cooperated with KDFW when it questioned him about the deer in November. He paid a $50 fine and court costs in January. The lawsuit filed in Franklin County on Apr 26 seeks nearly $1,900 in damages, which cover the cost of the investigation, prosecution, and disposal of the infected carcass.

Ben Robinson, who directs the KDFW's wildlife division, said in a statement, "The disease has been documented in every surrounding state except Indiana, so we want to keep it from spreading to Kentucky's deer and elk herds."

The World Health Organization's (WHO's) mpox emergency committee is meeting today for the fifth time to assess if the outbreak still warrants a public health emergency of international concern (PHEIC).

The WHO declared the emergency in July 2022 following the international spread of the virus. The emergency committee last met in February and typically meets every 3 months, or more often as needed.

In an address to the committee today, Tedros Adhanom Ghebreyesus, PhD, the WHO's director-general, said countries have made steady progress against the disease, which has come with a steep decline in cases. But he added that transmission continues in some communities, such as in the Western Pacific region, and travel-related cases continue to be reported.

Regarding Africa, where the virus is endemic, Tedros said there is no clear trend, and cases continue to be reported in several countries.

The WHO will host a telebriefing tomorrow on global health issues and will likely announce the emergency committee's latest recommendation.