Author Archives: yicheng zhu

The Next Step in Antibiotics

Did you know that not all types of bacteria in this world are harmful to humans? Some bacteria can be beneficial such as those used for the production of cheese and yogurt. Furthermore, these tiny creatures could even potentially be used to manufacture antibiotics for human use.

Antibiotics are used to cure bacterial infections by killing bacteria. For example, penicillin saved thousands of people in the 19th century.

Bacteria

As Amazing as they Sound, Antibiotics are not a Permanent Solution

The over-usage of antibiotics results in bacteria that can build resistance and cause the medication to be ineffective. The World Health Organization announced: “A serious threat is no longer a prediction for the future, it is happening right now in every region of the world and has the potential to affect anyone” on the development of drug-resistant bacteria.

Once a type of bacteria develops a resistance to a specific antibiotic, other antibiotics must be used to treat the infection. For example, nitroimidazole is a drug found in antibiotics such as azomycin. Due to its low resistance by bacteria, it has been used extensively to treat bacteria that have developed resistance to certain antibiotics.

Nitroimidazole

Research Looking into Nitroimidazole

Dr. Jason Hedges and Dr. Katherine Ryan of the University of British Columbia took a look into finding new ways to synthesize nitroimidazole. Their recent publication in 2019 showed how they were able to convert an amino acid (a building block of proteins) into azomycin. 

The researchers used bioinformatics, a data analysis tool, to find all previous work that has been done on this topic. Bioinformatic searches are performed on databases such as NCBI.

They found that back in 1953, azomycin was extracted from a strain of bacteria called Streptomyces eurocidicus. Furthermore, they found a specific gene in a separate strain of yeast called Streptomyces cattleya, which had similarities to S. eurocidicus

The two researchers aimed to find new ways to synthesize nitroimidazole, and proposed to synthesize nitroimidazole from L-arginine. Once a pathway had been developed, their end goal was to synthesize and extract azomycin in S. cattleya.

Hedges and Ryan were able to develop a multi-step pathway for the conversion of L-arginine to nitroimidazole through experimentation. However, they were unable to detect azomycin in S. cattleya. They noted that the gene of interest was unable to synthesize azomycin, and a separate drug may have synthesized in its place.

Synthesize of nitroimidazole from L-Arginine

A Bright Future

The significance of this research transcends the synthesis of azomycin. Although they failed to detect azomycin in S. cattleya, their work provides a stepping stone for further research to be conducted. This study provides insight on new biosynthetic pathways which is important to those currently in the field of life sciences and pharmacology. Furthermore, this study expands people’s knowledge of bacteria engineering and the biosynthetic pathway of other antibiotics. It also provides information about future antibiotic observations.

Future researchers could test their synthetic pathway on other bacteria such as E. coli to determine if azomycin could be synthesized.

Reference:

Hedges, J. B.; Ryan, K. S. In Vitro Reconstitution of the Biosynthetic Pathway to the Nitroimidazole Antibiotic Azomycin. Angewandte Chemie International Edition 2019, 58 (34), 11647–11651.

-Adrian Emata/Jackson Kuan/Xinyu Gu/Yicheng Zhu

 

 

 

Origin of the Coronavirus

Recently, the outbreak of new coronavirus has seriously affected people’s lives in countries and even around the world. New coronaviruses can be transmitted through air and contact. Symptoms include fever, cough, and difficulty breathing. In order to completely solve this infectious disease, it is very important to find the primary case.

Source:https://www.heywood.org/education/covid19-coronavirus-updates

Initially, Chinese scientists believed that the source of the virus was the South China Seafood Market in Wuhan, China. When people eat wild animals that contain the virus, the non-pathogenic version of the virus jumps from animal hosts to humans and then evolves into the current pathogenic state in the population. For example, the RBD structure of some coronaviruses from pangolins, armadillo mammals found in Asia and Africa, is very similar to SARS-CoV-2. Coronavirus from pangolin may have been transmitted to humans either directly or through an intermediary host such as a civet or ferret.

Source:http://m.cyol.com/content/2020-03/05/content_18413469.htm

Most people in this epidemic believed that this new coronavirus should be derived from flying mammals such as bats. Many people also criticized them, and even many people targeted the bats directly, thinking that those who eat bats Caused the disease. However, this is actually questionable. Although it is possible that bats can directly infect humans, so far, most of the time, bats are not the direct source of infection but are adapted to spread to humans through the intermediate source of infection. This can be seen from the case report published in the top medical journal “The Lancet”.

Source:https://news.sky.com/story/how-did-coronavirus-start-scientists-tackle-the-conspiracy-theories-11959500

Researchers from institutions such as the Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences recently published a paper in the form of a preprint, saying that they analyzed the genomic data of 93 new coronavirus samples in 12 countries on four continents and found that they contained 58 haplotypes, which are related to the South China Seafood Market The associated patient sample haplotypes were H1 or its derivative types, while the more “older” haplotypes such as H3, H13, and H38 came from outside the South China seafood market, confirming that the new crown virus of the South China seafood market was transmitted from elsewhere In perspective.

Source:https://meaww.com/coronavirus-did-chinese-officials-downplay-extent-of-deadly-wuhan-outbreak-in-early-stages

Finding an “index case” is equivalent to finding a weapon that can cut the epidemic from the source. But in the long history of humans fighting the epidemic, few “index cases” have been found. On the one hand, the timeline of the index case and first case are not necessarily the same, which makes the process of tracing like a needle in a haystack. In addition, the chain of evidence tracking “index case” is difficult to finalize and will always be repeatedly overturned and readjusted.

To this day, the epidemic of AIDS, Ebola, SARS and so on has never clearly identified the “index case” in the strict sense. From the perspective of the development of the global epidemic, it is still of great significance to curb the development of the epidemic while researching and developing effective drugs and vaccines and controlling the development of the epidemic in a timely manner. However, the new Coronavirus may be the same as AIDS and SARS. There is no way to accurately find the first human it infected.     

Yicheng Zhu

No Medicine to Cure

Can you imagine the world without medicine?

Nowadays, more and more bacteria begin to show resistance against antibiotics. Azomycin, a type of antibiotics used to treat multi-drug resistance is found to be used more and more frequently. What if bacteria start to grow resistance against Azomycin? However, it is actually nailed fact, the only question is when. In order to solve this problem, in 2019, Dr. Jason Hedges and Dr. Katherine Ryan of the University of British Columbia engaged in finding a new way to synthesize the nitroimidazole, the main component of azomycin.

source:https://www.reactgroup.org/toolbox/understand/how-did-we-end-up-here/few-antibiotics-under-development/

The study of antibiotics can be traced back to the 19th century. For these two centuries, antibiotics saved countless lives from all kinds of diseases. However, antibiotics can not kill all the bacteria. Every time when one bacteria survived from the massacre of the antibiotic, they grow the resistance against the antibiotic. Then it split, split and split. Finally, the survived bacteria become countless bacteria that can not be defeated by the antibiotic again. Thus, more and more bacteria begin to survive from the war with antibiotics, and more and more antibiotics become useless. Herein, the race between the evolving of antibiotics and evolving of bacteria begins. 

So, let’s take a look at what did Dr. Jason Hedges and Dr. Katherine Ryan do and what did they find.

By doing a lot of research, Dr. Jason Hedges and Dr. Katherine Ryan found that the development of nitroimidazole can be dated back to 1953 when azomycin was first found. And they noticed that when strain Streptomyces eurocidicus was produced, L-arginine is converted to azomycin. Therefore, they came up with a plan to synthesis nitroimidazoles by linking L-arginine to azomycin via in vitro reconstitution. 

In vitro reconstitution process of nitroimidazole. Source: Hedges and Ryan, 2019

Through the experiment, Dr. Jason Hedges and Dr. Katherine Ryan successfully synthesized nitroimidazole via in vitro reconstitution. But unfortunately, no azomycin was produced via Streptomyces cattleya. 

Although the experiment is failed to synthesis azomycin through Streptomyces cattleya, it still provides a lot of valuable information for further researchers. It points a direction on the biocatalytic pathway of azomycin synthesis and set the stage for the discovery of new antibiotics.

Reference:

Hedges, J. B.; Ryan, K. S. In Vitro Reconstitution of the Biosynthetic Pathway to the Nitroimidazole Antibiotic Azomycin. Angewandte Chemie International Edition 201958 (34), 11647–11651.

 

Yicheng Zhu

 

 

 

 

 

What is N95? ——The knowledge about face masks

Facing the outbreak of the new coronavirus, all kinds of face masks were sold out in the blink of an eye. More and more people seem to start to realize the importance of face masks.  But, do face masks really work? and how they work?

The answer largely depends on what type of face mask you are wearing.

Classification of Face Masks

According to the design of the face masks, the general ranking of the protective ability is (high to low): N95 masks> surgical masks> ordinary medical masks> ordinary cotton masks. But in the case of the new coronavirus, the most effective type of face masks are medical-surgical masks and masks filtering 95% or more of non-oily particles, such as N95, KN95, DS2, FFP2, etc. At present, China’s medical face masks are mainly divided into three types: medical protective masks with the highest protection level, medical-surgical masks commonly used in invasive operating environments such as operating rooms, and ordinary disposable medical masks.

 

How Face Masks Work?

Usually, medical face masks are made of non-woven fabrics, and its raw materials are mainly Polypropylene. And polypropylene layers are arranged to form an SMS structure.

SMS structure makes face masks capable to block floating particles while allowing airflow in and out the face masks. In this structure, the key material that brings the virus filtering effect is a high density, electrostatic layer lies in the middle: melt-blown non-woven fabric. When small particles like viruses get close to the melt-blown nonwoven fabric, it will be immediately captured by the electrostatic field and adsorbed on the surface of the non-woven fabric, and therefore prevent the virus gets into the body.
Yicheng Zhu

Toxic Receipt – Another BPA Problem After Baby Bottles

Remember BPA was banned for making baby bottles by the Canadian government in 2010 due to its hormone-disrupting? You may think the problem is solved but BPA is still sneaking into people’s bodies and harm people’s health through a thing we are using daily—receipt.

Source: http://k.sina.com.cn/

After almost every payment is made, whether needed or not, the receipt will be printed out. These receipts are usually made of Bisphenol A (BPA)-containing thermal paper, which is an ink-free choice for most of the banks, supermarket, pos machine, etc.  You may think that is not a problem since you will only touch it for a few seconds rather than use it for daily drinking.

However, researchers at the University of Missouri have shown that BPA found on the heat-sensitive paper used in shopping receipts can be absorbed through the skin, significantly raising BPA levels in the body.

What is BPA Exactly?

BPA is the initial of Bisphenol A, it is a chemical raw material that can be added to plastics to make them colorless, transparent, durable, lightweight and impact resistant. BPA was widely used in the manufacture of baby bottles, water bottles, sealants for dental fillings, eye lenses and hundreds of other commodities until banned in 2010.

BPA is an endocrine disruptor that can interfere with the body’s endocrine system by mimicking the effects of estrogen. When BPA shows hormone-like effects, the real hormones in the body may not work properly.

And what’s worse is….

BPA Absorption Increased Significantly After Using Hand Sanitizer 

One study showed that using hand sanitizer or other skincare products before handling receipts increases the absorption of BPA by up to 185 times, reaching levels that can lead to obesity, diabetes, coronary heart disease, infertility, and cancer.

The study mimics a common behavior seen in fast-food restaurants: wash your hands with hand sanitizer, hold the receipt for a while, and then eat with that hand.

By testing BPA on hands, they found that after using hand sanitizer, large amounts of BPA were transferred from heat-sensitive paper to hands in just a few seconds. BPA transfers hundreds of times faster than in dry hands.

Source: https://doi.org/10.1371/journal.pone.0110509.g002

This is because hand sanitizers and skincare products (such as soaps, sunscreens, lotions) contain “dermal osmotic enhancers” used to enhance the delivery of the active ingredients in the products. This enhanced effect leads to a rapid transfer of BPA through the skin.

BPA passed on to the hands is absorbed through the skin and under the tongue when eating, leading to higher levels of the chemical in the blood and urine.

Source: https://doi.org/10.1371/journal.pone.0110509.g002

So, next time, remember to dry your hands before touching the receipt and wash your hands afterward. Or simply tell the waiter that you don’t need the receipt.

—–Yicheng Zhu