BACTERIA, VIRUSES & OTHER PATHOGENS
Although polio is thought to be eradicated from large parts of the globe, it is now being found in wastewater in cities in Europe and the U.S. wastewater surveillance is an ongoing part of the polio eradica- tion efforts. Occasional low levels of VDP are not unusual. However, in 2022, London wastewater monitoring detected several strains of VDP, indicating the virus was spreading from person to person. Similar de- tections occurred in other major cities, including Jerusalem and New York. After a case of paralytic polio was reported in an unvaccinated man in Rockland County, New York, the polio virus was detected in two neighboring counties and New York City. This is alarming to public health officials, as even a single case of polio likely represents hundreds of asymptomatic infections and community transmission. In the U.S., polio vaccination rates for children approach 93%, but there are communities where vaccination rates may be as low as 60%. The New York case occurs in such a community, leading to ongoing concerns about community spread. Eradication efforts face global challenges of lack of access to healthcare, political unrest, and vaccine hesitancy. n For more on wastewater surveillance, read more on the previous page and go to hudsonalpha.org/wastewater to see how viruses are detected REFERENCES: Guglielmi, G., What polio’s UK presence means for global health. Nature (2022) 607, 225. DOI: 10.1038/d41586-022-01802-z “Wastewater Surveillance.” New York State Department of Health, April 2022, https://www.health.ny.gov/diseases/communicable/polio/wastewater.htm “Evidence of poliovirus (poliomyelitis) found in two more stool samples from Jerusalem and environs.” Israel Ministry of Health, 01 March 2022. https://www.gov.il/en/departments/news/10032022-01 https://polioeradication.org Gut microbes and brain injury Typical human gestation is 40 weeks, and any delivery before 37 weeks is considered premature. Extremely premature babies born before 28 weeks of gestation are at an increased risk for brain dam- age from complications like inflammation, sepsis, insufficient oxygen, and bleeding in the brain or heart. A study showed a link between the microorganisms that live in the human gut and the intensification of brain injury. The gastrointestinal tract is home to an assortment of bacteria, fungi, and microorganisms collectively called the microbi- ome. Because premature babies' microbiome and immune systems are not thoroughly developed, modifications in the microbial popula- tion may negatively impact brain development. Scientists studied the microbiome, The results indicated that four to six weeks after birth, the microbiome of these babies consisted primarily of Klebsiella bacteria, which is not typical in healthy infants. The dominance of Klebsiella was linked to atyp- ical immune development. In addition, a large Klebsiella population was closely tied to neurological damage. Microbial population shifts occur before changes in the brain, suggesting the possibility of therapeutic mediation that may nor- malize the Klebsiella population and lead to better outcomes for the babies. This was a small study, so further research should include greater numbers of participants across many neonatal units within diverse hospital settings. n immunological composition, and brain development in 60 premature infants. REFERENCE: Seki, D., et al. Aberrant gut-microbiota-immune-brain axis devel- opment in premature neonates with brain damage. Cell Host & Microbe (2021) 29:10, 1558-1572.e6. DOI: 10.1016/j.chom.2021.08.004 Gut bacteria interacting with intestinal villi
Amping up T cells to attack tumors In 2016, researchers discovered that the amino acid arginine makes T cells more resilient and more potent against tumors. They hypothesized that
Why is Polio reemerging? Polio is a highly contagious virus transmitted from person-to-person via droplets from the throat or fecal contamination. Most infected people show no symp- toms. Still, in a small proportion of people, poliovirus invades the spinal cord resulting in paralysis, permanent disability, and even death. The global incidence of polio has decreased by almost 99% since the invention of the polio vaccine in the 1950s. Since the initiation of the Global Polio Eradication Initiative in 1988, the CDC estimates that 18 million polio cases were prevented, and 1.5 million lives were saved by polio vaccination. There are two types of polio vaccines. The introducing more arginine into tumors could activate T cells and enhance immunotherapy. But getting the appropriate amount of arginine through diet alone is not feasible. A 165-pound person would need to consume 150 grams of arginine in their diet every day. The average dietary intake of arginine is only four to six grams per day, meaning people would need to consume 30 times more per day. It turns out that bacteria can be genetically engineered to produce many molecules, including amino acids. Bacteria can also be modified to colonize tumors preferentially. In a recent study, scientists engineered bacteria to produce the amino acid L-arginine inside tumors. A mutated version of a gene that con- verts ammonia into arginine was placed inside a strain of E. coli that doesn’t make people sick. When scientists injected the bacteria into colon tumors in mice, the bacteria produced arginine and attracted T cells to the tumor. However, additional immunotherapy was necessary to block the tumor’s T cell-inactivating defenses and allow the T cells to attack the tumor. Further studies are required to deter- mine if the bacteria could also prime tumors for immunotherapy in humans, but this is a promising study. n REFERENCE: F.P. Canale et al., “Metabolic modulation of tumours with engineered bacteria for immunotherapy,” Nature (2021) 598(7882):662–66. DOI: 10.1038/s41586-021-04003-2
Oral Polio Vaccine (OPV) contains a live, weakened virus administered orally. The Inactivated Polio Vaccine (IPV) is an intramuscular injection of noninfectious virus particles. The inactivated vaccine pre- vents the spread of the virus to the nervous system. However, it does not prevent the polio virus from
Oral Polio Vaccine
reproducing in the intestines meaning an infected person could shed and spread the virus. In areas of low vaccination, the oral vaccine is known to cause vaccine-derived polio (VDP), which occurs when the weakened virus in the oral vaccine begins circulating in a community. The virus mutates from host to host and regains the ability to cause disease and paralysis over time. For this reason, the inactivated vac- cine is used exclusively in most European countries and the U.S.
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