Battling Antibiotic Resistance: A Lab Scientist’s Guide

Introduction

Antibiotic resistance happens when bacteria evolve to withstand drugs that once effectively eliminated or inhibited them. During infection testing—specifically cultures—when microbial growth is detected, the next step is identifying and classifying the organism.

Techniques like Gram staining, biochemical tests, and colony morphology, are employed in this identification process.

But why is this step so important? It guides laboratory scientists toward the final and most vital stage: the sensitivity test.

This test determines the most effective antibiotics to target a specific infection. However, when a microorganism develops resistance to these antibiotics, it becomes a significant challenge, threatening both treatment and recovery.

This article explores strategies for identifying and managing antibiotic resistance, which is key to preserving antibiotic effectiveness and ensuring positive patient outcomes.

Let’s look at the first one.

 

Factors Influencing Antibiotic Resistance in Laboratories

Several factors contribute to the development of antibiotic resistance in laboratory settings:

Antibiotic Use and Misuse

Inappropriate Antibiotic Use: Overuse or misuse of antibiotics, such as incomplete treatment courses or incorrect prescriptions, encourages the development of resistance. In many healthcare settings, patients are often given antibiotics based on assumptions rather than accurate testing. This practice contributes to the rise of resistant strains in the population.

Self-medication: where patients act as their own doctors, is another key factor contributing to antibiotic resistance. When individuals self-prescribe antibiotics because they ‘worked before’ or because their symptoms seem to match something they found in a Google search, they unknowingly fuel resistance. This misuse of antibiotics can have serious consequences, not only for their own health but for public health as well.

 

Bacterial Factors

Genetic Mutations: Bacteria have this remarkable ability to develop resistance through genetic mutations. These mutations can happen spontaneously or be acquired through horizontal gene transfer from other bacteria. As a result, bacteria may produce enzymes that degrade antibiotics, alter target sites, utilize efflux pumps to expel the drugs, or reduce their permeability to antibiotics. These genetic adaptations make it increasingly difficult to treat bacterial infections effectively.

Biofilm Formation: Bacteria that form biofilms become “superbugs”, and with more resistivity to antibiotics. Biofilms create a protective barrier that shields bacteria from the effects of antibiotics, allowing them to thrive in otherwise hostile environments. Organisms like Pseudomonas aeruginosa and Staphylococcus aureus are notorious for forming biofilms, especially on medical devices, and are leading causes of hospital-acquired infections.

 

Laboratory or Environmental Factors

Media Composition: The composition of culture media plays an indispensable role in antibiotic resistance testing. If the media is not prepared according to the manufacturer’s instructions, it can lead to inconsistent results. Overly nutrient-rich media can give bacteria an advantage, promoting their growth and potentially contributing to antibiotic resistance by enabling them to thrive in conditions that mimic ideal survival environments.

Contamination: Contamination of the culture media can severely affect the accuracy of results. The presence of unintended microorganisms can alter the growth dynamics of the test sample, allowing resistant strains to flourish. This selective environment can favor bacteria with enhanced survival mechanisms, including antibiotic resistance, leading to skewed or misleading test outcomes

 

Steps for Laboratory Scientists to Identify and Address Antibiotic Resistance

Detection of Resistance:

• Antibiotic Sensitivity Testing: The cornerstone of identifying antibiotic resistance lies in performing standardized sensitivity tests, such as the disc diffusion test, broth microdilution, or using automated systems. These methods help determine the bacteria’s susceptibility to various antibiotics. Additionally, measuring the Minimum Inhibitory Concentration (MIC) provides precise quantification of the antibiotic’s effectiveness, allowing for better-informed treatment decisions.

when a sensitivity test shows resistance, then follow the next step.

 

Troubleshooting Culture Test Resistivity Issues

When faced with antibiotic resistance, follow these essential troubleshooting steps to ensure accurate results:

1. Evaluate Media Preparation: Carefully review the media preparation process to confirm that all components were correctly mixed and sterilized.
2. Assess Culturing Environments: Ensure optimal conditions by checking the pH, temperature, and humidity levels in the incubator.
3. Inspect for Contamination: Conduct a thorough examination of the media for any signs of contamination that could interfere with test results.
4. Identify Other Microorganisms: Check for the presence of non-bacterial organisms, such as Candida, that may complicate the interpretation of results.
5. Reassess Colony Typing: Re-evaluate the colony typing to confirm that the appropriate antibiotic disk selections were used.

After you have done this due diligence, and you are in the right track, go on and confirm what kind of resistance you are dealing with.

 

Conduct Confirmatory Tests:

To further investigate specific resistance mechanisms (e.g., beta-lactamase production), implement confirmatory tests like the Modified Hodge Test or the MRSA diagnosis in the cases of Methycillin Resistant Stap. Aureus.  There are selective media for isolating these organisms like MRSA.These tests provide vital insights into the nature of the resistance.

You can take it a step further.

Employ Molecular Methods:

Utilize advanced molecular techniques such as PCR and sequencing to identify resistance genes and mutations that contribute to antibiotic resistance. These methods offer precise information to guide treatment decisions.

Once these confirmations are completed, and the resistance profile is established (determining whether it is a multidrug-resistant [MDR] or extensively drug-resistant [XDR] strain), explore alternative treatment options to ensure effective patient care.

After these confirmations, Then, you will need to answer the question- What do you do now?

 

Treatment plan for antibiotic Resistance

Perform Further Sensitivity Testing

• Extended Antibiotic Susceptibility Testing: After detecting resistance, you may run additional tests to check if the bacteria will be susceptible to second-line or alternative antibiotics for example, they may test for susceptibility to carbapenems or colistin in cases of multidrug-resistant infections. (see https://medlabhq.com/mrsa-diagnosis-5-easy-tests-to-remember/).
• Combination Therapy Testing: In some cases, you may just need to use combinations of antibiotics to see if a combination therapy (using more than one antibiotic) will be effective against the resistant strain.

Reporting and Recommendations

• Provide Targeted Treatment Recommendations: Once you are dealing with antibiotic resistance, you need to  give detailed reports of the resistance patterns and suggest antibiotics that could still be effective based on your sensitivity testing results. These reports are then shared with the healthcare team to guide treatment.
• Suggest Alternative Therapeutic Options: For infections caused by highly resistant bacteria, as a laboratory scientist, you may suggest the use of alternative treatment methods, such as bacteriophage therapy (use of viruses to kill bacteria) or new antibiotics.

 

Preventive Measures to Combat Antibiotic Resistance

• Antibiotic Stewardship:
  Actively engage in antibiotic stewardship, advocating for the responsible use of antibiotics. Discourage your patients, or the public at large from overuse and misuse of antibiotics. The more they are aware, the more we can reduce the crisis.
• Adhere to strict infection control practices: Because the hospital and health facilities have become incubators of Antibiotic Resistant Bacteria, high standard of hygiene, isolation protocols, and  disinfection procedures must be followed at all times. These measures will prevent the spread of nosocomial infections and protect both patients and healthcare staff.

 

Recommendations for Combating Antibiotic Resistance

Every laboratory personnel should be involved in Research and Development:

• New Antibiotics:
  Stay up-to-date on the development of new antibiotic agents and alternative therapies to enhance treatment options.
• Understanding Resistance Mechanisms:
  Engage in research efforts aimed at understanding the mechanisms of resistance, which is important in finding new ways to fight Drug Resistance.
• Education and Training:
  Ensure that both laboratory and clinical staff receive comprehensive training on resistance mechanisms, testing methodologies, and how to respond appropriately to resistance findings.
• Public Awareness:
  Foster awareness among patients and the general public regarding the importance of correct antibiotic use and adherence to prescribed treatments to prevent the spread of resistance.

 

CONCLUSION

Antibiotic resistance is not just a medical dilemma—it’s a race against time, where every misstep in detection or prevention can cost lives. As gatekeepers in the fight against resistant infections, laboratory scientists hold the power to influence the future of healthcare. Through diligent sensitivity testing, uncovering the roots of resistance, and championing preventive strategies, they are at the forefront of safeguarding the efficacy of antibiotics for generations to come.

 

REFERENCE

• Laboratory systems as an antibacterial resistance containment tool in Africa https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5433813/
• Antimicrobial Activity and Resistance: Influencing Factors – PMC – NCBI https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5468421/