iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
In a 2020 laboratory study, Escherichia coli grew during ampicillin exposure when cultured with Bacillus subtilis, even though the pattern was reversed when the species were grown separately. The shift was a change in the community’s growth response—not evidence that either bacterium acquired genetic resistance. The researchers linked it to differences in how the two species inactivate ampicillin, which changed the drug available to each population.
What happened when the bacteria were grown together?
Leticia Galera-Laporta and Jordi Garcia-Ojalvo compared non-resistant B. subtilis and E. coli grown alone and in coculture under moderate ampicillin exposure. In monoculture, B. subtilis was comparatively tolerant while E. coli was sensitive. In coculture, the population-level pattern flipped: E. coli could proliferate in the presence of ampicillin, while B. subtilis could not.
The authors called this an “antithetic” population response: the two species’ relative growth responses in the mixed community contrasted with their responses when isolated. Their mathematical model, constrained by the species’ separate responses, predicted the reversal. The experiment concerned a particular pairing, antibiotic, and set of controlled laboratory conditions; it does not establish that this pattern is universal.
Recommended Free Tools
Why did the response change in coculture?
The researchers attributed the reversal to differences between the species in how effectively they inactivate ampicillin. When both species are present, their interactions alter the amount of active drug available in the community. That change in drug availability can affect each population differently, making the mixed-community outcome unlike either species’ response on its own.
#1 Best Overall
- BIOTECH QUALITY, FRESH AND READY-TO-USE: Factory-direct fresh 10 100-mm Pre-poured sterile LB-agar plates and 10 sterile 6-inch long swabs (in 5 pouches). Our plates are manufactured in USA using the biotech GMP standards. Each plate has a fresh and thick layer of agar. Fresh plates promote faster and more bacterial growth as compared to aged stored plates. Re-sealable packaging is convenient for re-use.
- The Safest Agar Plates On Amazon: Luria Broth(LB) agar plates are used to detect environmental microorganisms all over the world. They are the safest agar plates to be used by students in the classroom or at home.
- Free Science Fair Project E-Book: Packed with easy-to-do science fair experiments with clear step-by-step instructions to help you win a science fair competition. These experiments are scientifically designed and tested to ensure your success. Tips and advice are provided to avoid common mistakes.
- PEACE OF MIND: Any questions? No worry. Inside the kit you will find a toll-free number that you can call in case you have a question about the product. You will receive immediate live support from PhD scientists with extensive hands-on experience. Before you buy or try, check out the vendor to see whether it has a telephone number or a physical address.
This is a community-context effect, not a claim that E. coli gained a new resistance mutation during the experiment. The authors emphasized that the bacteria’s molecular sensitivity did not change; instead, the collective response changed because the other bacterial type altered drug availability.
Does this mean the bacteria evolved antibiotic resistance?
No. The study does not report genetic evolution of resistance. It describes a shift in population growth under antibiotic exposure when the species were together, associated with their different effects on ampicillin. “Tolerance” in this result refers to the observed ability of a population to grow in the tested conditions; it should not be read as proof that the bacteria acquired heritable resistance or that their intrinsic sensitivity changed.
Rank #2
- BIOTECH QUALITY, FRESH AND READY-TO-USE: Factory-direct fresh 10 100-mm Pre-poured sterile LB-agar plates and 10 sterile 6-inch long swabs (in 5 pouches). Our plates are manufactured in USA using the biotech GMP standards. Each plate has a fresh and thick layer of agar. Fresh plates promote faster and more bacterial growth as compared to aged stored plates. Re-sealable packaging is convenient for re-use.
- The Safest Agar Plates On Amazon: Luria Broth(LB) agar plates are used to detect environmental microorganisms all over the world. They are the safest agar plates to be used by students in the classroom or at home.
- Free Science Fair Project E-Book: Packed with easy-to-do science fair experiments with clear step-by-step instructions to help you win a science fair competition. These experiments are scientifically designed and tested to ensure your success. Tips and advice are provided to avoid common mistakes.
- PEACE OF MIND: Any questions? No worry. Inside the kit you will find a toll-free number that you can call in case you have a question about the product. You will receive immediate live support from PhD scientists with extensive hands-on experience. Before you buy or try, check out the vendor to see whether it has a telephone number or a physical address.
What does the result mean—and not mean—for infections?
The finding shows why a response measured for one species in isolation may not predict the behavior of a mixed bacterial community under the same experimental conditions. It raises a relevant scientific question for infections containing multiple species, but the study did not test a human infection, establish a clinical intervention, or show that this exact pairing or effect occurs in conditions such as cystic fibrosis, wound infections, or gum inflammation.
Free tools Windows power users keep installed
One-click scans. No signup required.
It also does not demonstrate that a probiotic or other commercial product can safely manipulate a pathogen’s response to antibiotics. The result is evidence about ecological interactions in a controlled in vitro experiment, not treatment advice. The paper was published in Science Advances on 6 March 2020: Galera-Laporta and Garcia-Ojalvo, “Antithetic population response to antibiotics in a polybacterial community”.
Quick Recap
Best Value
- Biotech Quality, Fresh and Ready-to-Use: Factory-direct fresh 10 100-mm Pre-poured sterile LB-agar plates and 10 sterile 6-inch long swabs (in 5 pouches), 2 sterile dilution tubes and 2 transfer pipets. Each plate has a fresh and thick layer of agar. Re-sealable packaging is convenient for re-use
- Student & Teacher Friendly Design: Formulated specifically for educational environments, science fairs, and home experiments, ensuring safe and effective learning experiences
- Free Science Fair Project E-Book: Packed with easy-to-do science fair experiments with clear step-by-step instructions to help you succeed in science fair competitions. These experiments are scientifically designed and tested to ensure your success. Tips and advice are provided to avoid common mistakes
- Live Technical Support: Receive immediate live support from PhD scientists with extensive hands-on experience to answer any questions you may have during your experiments
- Complete Educational Kit: Includes all necessary components for conducting bacteria experiments including pre-poured agar plates, sterile swabs, dilution tubes, transfer pipets, and detailed instructions for successful science projects
Rank #4
- THE COMPLETE SCIENCE KIT: Start your science experiment journey with our kit, complete with 10 pre-poured agar plates, 10 cotton tipped sticks, 1 pipette, 1 plastic vial to be used in experiments, simple-to-follow instructions, and an informative science experiment ebook project guide. This product is intended for ages 15 years and older.
- RELIABLE & SECURE: Experience the height of science education with our kit, created for educational purposes. These agar plates include a thick agar layer, that are ready to use for your experiment. The customized packaging are more durable than conventional solutions.
- CONVENIENTLY PRE-POURED FOR EASY USE: Our pre-poured, ready-to-use nutrient agar petri dishes eliminates the need for technical agar melting and pouring. Our skillfully concocted plates facilitates proper agar consistency and thickness.
- THE EXPERIMENT EBOOK: Get creative and think of thrilling ideas to experiment in the classroom with our science kit that includes an exciting experiment ebook. The eBook is filled with simple experiments that come with clear step-by-step instructions to help you succeed!
- WE VALUE CUSTOMER SATISFACTION: We believe that you will enjoy your science fair project kit and would even suggest it to your acquaintances. However, if you are not entirely satisfied with it, please let us know and we will make things right.
Rank #3
- SAFE IS OUR PRIORITY - Our plates are sterilized using biotech industry standards. They are proved to be safe for kids.
- BIOTECH QUALITY, FRESH AND READY-TO-USE: Factory-direct fresh 10 100-mm Pre-poured sterile LB-agar plates and 10 sterile 6-inch long swabs (in 5 pouches). Our plates are manufactured using the biotech GMP standards. Each plate has a fresh and thick layer of agar. Fresh plates promote faster and more bacterial growth as compared to aged stored plates. Re-sealable packaging convenient for re-use.
- COMPLETE SCIENCE KIT - The AGAR PLATES kit contains everything you need to carry out the science experience. Each kit includes 10 pre-poured agar plates, 10 sterile cotton swabs, 2 plastic droppers, and a easy to follow science experiment project guide.
- CONVENIENT, PRE-POURED PLATES. Our plates are ready-to-use. No need to prepare the plates yourself.
- WE VALUE CUSTOMER SATISFACTION: We believe that you will enjoy your science fair project kit and would even suggest it to your acquaintances. However, if you are not entirely satisfied with it, please let us know and we will make things right.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
