Antimicrobial Strategies for Respiratory Infections

Introduction

Respiratory infections are troublesome and significantly burden people of all ages. They encompass multiple diseases which affect the upper and lower respiratory tract. An array of microbes like bacteria, fungi, and viruses causes them. Therefore, a multidirectional approach, mainly with antimicrobial agents, is advised for effective management. These strategies are used in a personalized manner with the intent to combat the infectious agent and help overcome it.

What Are Respiratory Infections?

They can be divided into:

• Upper Respiratory Tract Infection: This is commonly known as a common cold. The cause is viral. Patients suffering from this show symptoms like sneezing and runny nose.

• Lower Respiratory Tract Infection: Bronchitis and pneumonia are more commonly seen. Viruses, bacteria, fungi, or a combination often cause it.

Knowing the source and cause of the disease is very helpful in effective management.

What Are Antimicrobial Strategies?

Various strategies have been devised against the growth and spread of infection-causing microorganisms.

They are:

• Antibiotics: These are very crucial for respiratory infections. Care should be taken to refrain from using or, if not, use as per the doctor's instructions. These can lead to resistance. Combination antibiotics are also employed. This gives a synergistic effect. Antibiotics mainly include

• Penicillins.

• Cephalosporins.

• Macrolides.

• Tetracyclines.

Mechanism of actions:

• Targeting Bacteria Directly: Either by inhibiting their growth (bacteriostatic) or killing them (bactericidal).

• Cell Wall Breakage: Penicillins like Amoxicillin and Augmentin work this way by disrupting the bacterial cell wall. This makes the structure weak, making the defense weak.

• Inhibiting Protein Synthesis: Macrolides and tetracyclines work this way by binding to ribosome units. This hinders bacterial replication and multiplication, promoting infection control.

• Interfering DNA Replication: Mainly by inhibiting the gyrase enzyme, they prevent the replication of bacteria.

They mainly target bacterial cell structures, making them porous and disrupting their ability to cause infections.

• Antiviral Medicines: Antiviral drugs like Oseltamivir and Ramdesvir have challenged multiple viral infections. The mechanism of action is to inhibit the neuraminidase, thereby helping to reduce influenza symptoms. Remdesvir is a broad-spectrum antiviral that became popular during the 2020 COVID-19 pandemic. Its mechanism of action interferes with the replication of the virus, significantly reducing the viral potential.

• Immunomodulators: They are targeting the body's defense. They perform targeted therapy. Their intention is to modulate the immune responses, potentially leading to tissue damage. They include:

  1. Interferon Therapy: Interferons are a group of proteins that signal in the body's defense. They can be administered against certain viral respiratory infections. They mainly work by activating antiviral mechanisms and inhibiting virus replication.

  2. Biologics: Numerous medications have been developed that target important infections affecting the lungs and respiratory system. They work by modulating the hyperinflammation seen, especially in cases of COVID-19, thereby considerably reducing the disease's complications.

• Personalized Treatment: Palivizumab is a monoclonal antibody used in high-risk patients to prevent respiratory infections.

• Phage Therapy: Bacterial predators are a treatment modality that can be used as an alternative to antibiotics. These viruses infect and replicate with bacteria. This treatment utilizes the specific property to target and destroy specific bacterial cells. With growing concern about antibiotic resistance, this treatment has become popular again.

• Nanotechnology: Offers advanced modes of drug delivery, thereby reducing the unwanted effects of drugs. This improves the bioavailability of drugs, giving sustained release. Nanotechnologies work at molecular and atomic levels. This enables precise control, showing immense help in infection control. Silver, zinc oxide, and titanium dioxide nanoparticles are utilized for their antimicrobial effects. Such minute sizes contribute to a higher surface area-to-volume ratio, showing greater efficacy against microorganisms. Nanoparticles can interact with an envelope of the viruses, thereby disrupting their cell structure and making them inactive.

• Vaccinations: Primary prevention occurs before the disease starts. Vaccines work by stimulating the immune system to recognize the microorganism. Once identified, they make the immune system remember it too. So, another exposure to the same microorganism increases the defense without causing disease. For example, the Influenza vaccine against seasonal flu and the COVID vaccine promote herd immunity, which means a significant portion is immune to disease.

What Are Empirical Therapy and Targeted Therapy?

Empirical therapy is based on clinical symptoms, without precise knowledge of which organism is cousin to the disease. It is a general approach where the clinician starts the patient on broad-spectrum antibiotics. Generally, Amoxicillin or Augmentin is prescribed. This helps in rapid initiation, especially in severe cases or life-threatening events. Targeted therapy involves targeting specific microorganisms after identifying the causative agent. This approach is guided by various tests like culture and sensitivity tests and molecular assays, which help determine the organism involved. A specific antibiotic is then prescribed targeting the microorganism.

What Are the Challenges of Antimicrobials?

• Antimicrobial Resistance: The overuse and misuse of antibiotics contribute to growing strains of resistant microorganisms, which seriously threaten public health and undermine the existing antibiotic treatments.

• Inadequate Diagnosis: In many cases, a prescription needs to be based on a sound diagnosis. This leads to unnecessary use and, therefore, overprescription, which can lead to antimicrobial resistance.

• Access Disparities: Rural areas globally cannot afford and access these medications. This leads to inadequate treatment and a higher death rate.

• Less Research as Less Investment: Economic challenges are posed to research this area and explore novel approaches.

• Over-the-Counter Availability: This leads to self-medication, contributing to overuse, inadequate dosages, and resistance.

• Complex Microorganisms: The organisms involved in disease are multiple, interacting with each other, and can also have synergistic effects.

Indiscriminate use disrupts the natural balance of good and bad bacteria in the body. To overcome this, careful and thoughtful research on antibiotic prescriptions should be done. Patients should also follow the doctor's advice. The use of probiotics alone also helps overcome the imbalance. This is intended to optimize patient outcomes without compromising their health. Implementing standard guidelines and protocols is crucial to promoting this.

Conclusion

The world of microorganisms and antimicrobials reflects a dynamic and ever-evolving medical field. From traditional antibiotics to advanced technologies like bacteriophages, nanotechnology particles have expanded the potential to protect against microorganisms. Currently, personalized interventions and targeted therapy are encouraged to reduce resistance. Vaccines also protect individuals and also provide community-wide immunity. Integrating diverse antimicrobial strategies becomes crucial as the challenges of microorganisms and drug resistance increase. A blend of research, education, and careful prescription is necessary to help this issue globally.