Introduction

What are streptococcal infections?

Streptococcus is a gram-positive bacterium consisting of 100 species that can cause infections ranging from mild sore throats to pneumonia. Unlike humans, these bacteria survive without oxygen and can easily thrive inside the human body. 

Streptococcus is mostly found in the upper respiratory tract and genital tract in humans. Generally, these bacteria are harmless but sometimes they can cause trouble.

Some pathogenic strains of streptococcus are Streptococcus pyogenes, S. pneumoniae, and S. agalactiae causing infections like sore throat, pneumonia, sepsis, and more that will be discussed further in the article.^1,2

Antibiotics

Antibiotics are the first line of treatment used to treat bacterial infections, these are pharmaceutical agents targeting specific sites of bacteria, relieving symptoms. 

Antibiotics have been used as a treatment for a long time but in the past few years, there has been an increase in antibiotic resistance also known as AMR.

The reason for AMR is with the necessary use of antibiotics bacteria evolve quickly. Just like humans, bacteria also evolve into their best versions which results in reduced antibiotic effectiveness³

To find the correct medicine we need to understand the different types of diseases, their symptoms, and proper medication.

Classification of infection

The genus Streptococcus is divided into different groups based on their cell wall antigens, but in this article, we will discuss Group A and Group B

• Group A streptococcus (GAS)

This group of bacteria are common pathogens

Example: Streptococcus pyogenes

Infections caused are scarlet fever, impetigo, cellulitis, acute rheumatic fever, sore throat (pharyngitis)²

• Group B streptococcus (GBS)

This species infects infants, children, pregnant women, and adults with health conditions

Example: Streptococcus agalactiae

Infections caused are bacteremia, sepsis, meningitis, pneumonia⁴

• Pneumococcal streptococcus 

This bacteria commonly causes pneumonia, neonatal sepsis, meningitis, and sinusitis.²  

Example: Streptococcus pneumoniae

According to the WHO 2017 list pneumoniae is listed among the top 20 pathogens.³

Antibiotic choices for infection

GAS infection

• Penicillin is the first antibiotic used in treatment.  They act by inhibiting bacterial cell wall synthesis. Generally, a 10-day course of penicillin can treat pyogenic infection
• Advantage – they are target-specific, low cost, and have less side effects
• Limitation – there is a rise in penicillin-resistant genes found in pyogenes and some people are allergic to the penicillin drug

Alternative treatment to solve the above limitations include using other types of antibiotics are used

1. Amoxicillin

They have similar mechanisms as penicillin but they are more effective. Similar to Penicillin 7-10 day course of amoxicillin can kill the bacteria and relieve  the symptoms ⁶

2. Cephalosporin is favoured over penicillin because of its broad spectrum. These are used in case of Penicillin-resistant strains of bacteria⁵
3. Macrolides ( azithromycin)- they are widely used in penicillin-resistant genes, but a concerning rise in macrolide-resistant genes is observed²

 GBS infection

• Penicillin is always the first line of medication used, and is a core medication to treat early-diagnosed GBS They can be taken orally, generally for 14 days or more.
• GBS is sensitive to Penicillin and amoxicillin
• Clindamycin– is given when a person has a penicillin allergy, but clindamycin-resistant genes are developed
• Cephalosporin ( cefazolin)- a broad-spectrum antibiotic, is effective against large groups of microbes. They are used to treat skin infections^2,4

Pneumococcal infection

Broad-spectrum antibiotics are more effective in treating pneumoniae infection

• Penicillin– is used to treat pneumonia affecting individuals, but the use of penicillin is decreased due to a rise in resistant strains of pneumoniae³
• Fluoroquinolones ( levofloxacin)- act by inhibiting the DNA enzymes of bacteria. They are only used when primary treatment doesn’t work or the strain is resistant to multiple drugs. There are very few cases of levofloxacin resistance
• Macrolides are used in case of penicillin- resistance, they are primary treatment drugs and can also be given in combination with cephalosporin. But there are macrolides-resistant strains in many regions, while some region has low resistance some have high⁷
• Other antibiotics used include carbapenems, vancomycin, and rifampicin³

Considerations in antibiotic selections

According to WHO, AMR is one of the greatest threats to mankind that needs immediate attention.

The development of antibiotic-resistant genes in microbes is a major cause of treatment failure. Many of the antibiotics used have seen a rise in resistant strains.

In the case of pneumonia, the core antibiotics like penicillin, amoxicillin, and macrolide-resistant are concerning.

There is a need for the detection and development of new treatment strategies because the effectiveness of current antibiotics is decreasing due to AMR.

Scientists are working to create effective drugs, some of which are successful in clinical trials. Understanding the resistant mechanism of microbes can help researchers in drug development.^2,3

Apart from new drugs, limited use of antibiotics should be advised. You should take antibiotics after proper diagnosis because sometimes viral and bacterial infection symptoms are similar, but antimicrobial agents don’t work for viral infections. Proper medical prescription also plays an important part in reducing the misuse of antibiotics

Apart from medicines, we should follow healthy and clean food hygiene and proper hand hygiene.

AI in AMR

Just like in every field, AI is also used in healthcare,

• They can improve prescription
• Investigate the trends and level of AMR
• Drug Development and Innovations in Present Antibiotics³

Guidelines and recommendations 

CDC rules for anti-microbial drug utilization

ICMR rules for the correct utilization of antimicrobial drugs

WHO guidelines on antibiotic drugs, bacterial contamination

The above-mentioned links are CDC, ICMR, and WHO guidelines that describe the correct use of antibiotics, dosage, route of administration, and different types of microbial infections.

Future aspects

Currently, antibiotics are widely used solutions in treating microbial disease. They are available in the form of drugs, ointments to treat skin infections or intravenous fluids. Urgent modification in existing medicine and the development of new antibiotics is required.⁸

The research and development focusing on the creation of new antibiotics has increased, and many countries have realised the problem of AMR.herefore implementing innovative research strategies in developing antimicrobial agents. Many of the recently created antibiotics are already in the clinical phase, but out of these antibiotics, few are effective top pathogens in the WHO list.

One of the possible strategies to tackle multidrug resistance is to damage the biofilm of bacteria. Biofilm is the external structure that protects microbes from the external environment and antibiotics. 60% of microbial contamination is due to biofilms.  By destroying the biofilm, the bacteria will become sensitive because the antibiotic can easily penetrate inside the bacteria. 

To treat bacterial strains with multidrug resistance combination drugs are preferred.⁹

Technological advances are also helping researchers understand the resistance mechanism of bacteria to multiple antibiotics. The following years are crucial in the development of antibiotics.

Summary

Streptococcus is a bacterial genus consisting of different species that are pathogenic causing infections in different age groups. Some of the infections are mild and can be easily treated within days like sore throat. However, some are more severe and require proper medical attention like pneumonia.

Our immunity plays an important part in fighting against these pathogens but they are not enough. Therefore to completely eradicate the bacteria inside the body, we use antibiotics. Antibiotics to date are the only proper medication given in treating bacterial infections, they are target specific to bacteria, and they kill bacteria through damaging cell walls, protein synthesis, or disrupting DNA synthesis. 

However, the excessive use of antibiotics and bacterial evolution have made the bacteria resistant to currently used antibiotics called AMR which is now a global threat. Therefore, to prevent AMR people need to know about the importance of the correct use of antibiotics, there are various guidelines and educational materials on websites to guide people about anti-microbial drug use. In addition with guidance, there is a need for new developments of antibiotics that can withstand the changing bacteria.

FAQs

Diagnostic tests to find if you have resistant genes?

  There are different methods of AMR diagnosis: 

• Conventional method- this includes manual, automated diagnosis and molecular-based PCR tests and microarrays
• Non-conventional method- they are based on whole genome sequencing, MALDI-TOF MS

 Some of the tests are currently used while some are underdeveloped. The limitations of these tests are cost and time-consuming.

Who is more at risk of streptococcal infection?

 These microbes generally infect infants, children, pregnant women, and adults with critical health conditions. Recently, there has been a rise in infections in older people. 

Which of the diseases is life-threatening?

Streptococcus rarely causes lethal infections, but if the disease is left untreated, it can be severe. It causes infections in the respiratory tract, genital tract, and skin, which, if diagnosed early, can be treated with the correct antibiotic course. Although treatments are available, one must be careful and maintain proper health and food hygiene. 

How does one get streptococcal infection?

Streptococcus is a contagious infection, that is spread through droplets, sharing foods, or even a handshake with the infected person. A sneeze or cough from an infected individual can infect more than one person. So, if someone is infected make sure to use a mask.