The Micro-wars

A four-year-old child should live with the simplicities of life in their parents’ home without cares or fears. However, that is not a reality for some children. War does not favour anyone involved either willing or forced. War creates long and stressful days and nights that are reflected in nightmares.

I remember when I was four years old I was woken up, by the city security sirens because of an unexpected missile attack to my home city. Screams from my sister echoed throughout my house as fear overtook her. Multiple cracks appeared on the walls and jumped in length as the new unwanted vibrations shook us. We had to evacuate instantly and go the safe shelter. My parents were filled with anxiety, uncertainty and fear. My mom held my younger sister, my dad led my mother and I, hand in hand to through the streets to the safe shelter.

My family survived that war and enjoyed a peaceful life after. However, peaceful is just a perspective although missiles no longer fly through the air, the nightmares still remain. War brings destruction and pain, caused by the ill will of humans. Although I may not be able to change the past or control others, anyone can change the future. I decided to work hard through my academic career to have a positive impact on the quality of human’s life and bury those dark memories. However, my research project has increased my concern about the unforeseen war against humanity by microorganisms in the world.

After I started my PhD research my perspective to the life has changed greatly. I developed a deep comprehension of the microscopic wars that we face. These micro-wars have ever lasting battles against humanity, with the tides of battle changing constantly.

Since early 1880s infections caused by “Staphylococcus aureus” were documented and appeared to be common in hospitals. In the 1940s, penicillin was introduced and became the first antibiotic against Staphylococcus aureus infections. Unfortunately, this new antibiotic created another issue from the overuse, or possible misuse. This issue created was an evolutionary strand of Staphylococcus aureus. As a result, penicillin began struggling against the growth of Staphylococcus aureus in human’s body after only two years.

In 1959, a stronger antibiotic (methicillin) was introduced to assist in stopping the growth of resistant Staphylococcus aureus to penicillin. After a while, even methicillin started to struggle as new resistance was observed. The first case of methicillin-resistant Staphylococcus aureus infection(MRSA) was reported in England in 1961. Since then multiple new antibiotics have been introduced all from the penicillin family. These antibiotics have continuously fought against MRSA infections in hospitals. However, even now it is still evolving and developing different resistant mechanisms to survive against the strongest current antibiotics.

After three decades, this microscopic war between humanity and Staphylococcus aureus infections continue to emerge. Healthy individuals have been getting infected at schools, dorms, gyms, and day care facilities with a new community strain. These individuals have not been hospitalized around the time of infection. They were infected by MRSA through touching an unknowingly contaminated surface. This displays that Staphylococcus aureus has found a pathway into the environment.

Methicillin-susceptible Staphylococcus aureus (MSSA) is another type of Staphylococcus aureus infection that is being observed in multiple environments. MSSA is currently weak to antibiotics, but it can easily obtain the antibiotic resistant gene from the environment and can easily evolve into MRSA. Unfortunately, all Staphylococcus aureus infections can cause death to humans. In just the United States, about 120,000 cases of bloodstream Staphylococcus aureus infections were reported in 2017. Among these infected individuals, 20,000 cases were resulted in death.

Identification of the potential sources of MRSA in the environment is a critical step to contain the spread of MRSA. There are debates that engineered systems such as wastewater treatment plants are assisting the spread of MRSA into the environment. All wastewater is full of different bacteria and viruses. The normal bacteria and viruses found in wastewater can easily come in contact with MRSA in the wastewater. Once contact is made, MRSA can continuously exchange genetic information throughout the treatment processes. This continuous exchange is a survival mechanism for MRSA. Whenever viruses come into contact with MRSA, they can take or share genetic information. Viruses can circulate much faster in wastewater and easily multiply the presence of resistant genetic information.

I started my research project by examining the possible sources of MRSA. Wastewater treatment plants were targeted because of the connection to the community and hospitals. I selected two primary wastewater treatment plants in Lexington, Kentucky, Town Branch and West Hickman. The Town Branch wastewater treatment plant collected urban sewage from the University of Kentucky, seven hospitals, two prisons, the Bluegrass airport, and industrial units in the north part of the city. West Hickman wastewater treatment plant collected suburban sewage from the developing sprawl in south part of the city. These two wastewater treatment plants have very similar processes with flow, and design. However, discharge points of the treated effluent are isolated from each other.

Sewage samples were collected from untreated wastewater, final sedimentation tank, and fully treated wastewater at the end of the wastewater treatment plants before the discharge point. Samples were processed in microbial lab at the University of Kentucky. Unexpected results displayed a higher presence of MRSA and MSSA in the sewage samples from West Hickman over Town Branch. Meaning that the suburban area has a higher presence of MRSA and MSSA, than the hospital dominated area. The research also displayed Staphylococcus aureus strains related to hospitals and communities were found together in both areas. This is a good indicator that Staphylococcus aureus is actively spreading throughout the city.

Fully treated wastewater from the West Hickman treatment plant contained MSSA. Considering the volume of water sampled versus the volume that flows through, it is highly possible that large amounts of MSSA are being discharged into a natural creek that leads to the Kentucky River.

These results display that the chlorination process in wastewater treatment plants needs to be redesign, to protect public health. Currently, E. coli is used as a design standard. However, E. coli is not resistant to chlorination process, Staphylococcus aureus is. Discharge of resistant bacteria into natural creeks affects the balance of natural microorganisms in the environment. More research needs to be funded and completed to accurately address this problem. The public health faces a current and future dangers since the surface water is used for recreational purposes, if left unaddressed. Issues arise as well from downstream areas where the water is collected for water treatment plants. Water treatment plants distribute the water to the public, which could be potentially spreading the issue further. The time to act is now! We need to improve the environmental quality, prevent needless disease, human suffering, and control the micro war against humanity. Engineers and researchers need to work together to improve the engineered systems to prevent the bacteria from entering into the environment and protect the public health. We need to win this microscopic war!

This article is based on the following research paper:

Prevalence and characterization of Staphylococcus aureus in wastewater treatment plants by whole genomic sequencing