Potent Antibiotic Identified in Kenyan Ant to Counter Antibiotic-Resistance Microbes

Antibiotic-resistant bacteria, termed superbugs, methicillin resistant Staphylococcus aureus (MRSA)now can be treated with a potent antibiotic which was discovered from an unlikely source- bacteria that are found on ants! The study titled 'Formicamycins, antibacterial polyketides produced by Streptomyces formicae isolated from African Tetreponera plant-ants' was published in the journal Chemical Science. A research team from the University of East Anglia (UEA) has identified a species of the Streptomyces bacteria family, which was isolated from, Tetraponera penzigi, the African fungus-growing plant-ant. The new species has been named Streptomyces formica, while the antibiotic obtained from it is called formicamycins, which is latin for ant.

Potent against Antibiotic Resistant Bacteria

The latest laboratory tests which were conducted on the newly identified antibiotics have shown that they are effective even against

• Vancomycin-Resistant Enterococci (VRE)
• Methicillin resistant Staphylococcus aureus (MRSA)

These bacteria are known to cause severe life-threatening conditions as they cannot be controlled by the use of antibiotics.

Antibiotics

The currently used antibiotics are derived from the group of bacteria called actinomycetes which were identified in the soil nearly half a century ago. That period is known as the Golden age of antibiotics.

The indiscriminate use of antibiotics has resulted in antimicrobial resistance (AMR), a condition in which the infective bacteria fails to respond to antibiotic therapy due to evolved mechanisms of resistance.

According to Dr. Matt Hutchings from University of East Anglia, the chemical ecology formed between bacteria that produce antibiotics and insects that grow fungus, a protective symbiosis, is a key area of study that will aid in identifying a new source of anti-infective drugs. An example of this relationship is the Kenyan plant-ants which exist in symbiosis with acacia trees. These ants are found to live in the hollowed structures of the thorny tree while growing fungus in the trees feed the ants. This relationship is equally beneficial to the tree as animals, including elephants, will not eat plants when they are covered with ants.

Antibiotic Resistance

The growing resistance to antibiotic therapy threatens treatment and prevention of infections that were caused by viruses, bacteria, parasites as well as fungi. This is a serious global threat which has called for action of leading government and non-government organizations across the world.

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In the absence of an effective antibiotic therapy, surgeries and chemotherapy for cancer are compromised. There are additional medical costs incurred due to the added hospitalization costs and treatment.

Antibiotic resistance leads to 480,000 people developing tuberculosis which is multi drug resistant. Apart from TB, antibiotic-resistant strains of bacteria threaten to affect therapy for AIDS as well as malaria.

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The resistance to antibiotics is developed when the microbes are exposed excessively to these antimicrobial agents. These strains are sometimes termed superbugs. Due to the development of resistance,

• the drugs that are used for therapy become ineffective
• the strains of microbes spread rapidly
• inability to treat even common infections
• prolonged illness, disability or death of the patients
• organ transplant, caesarean sections, hip replacements, management of diabetes or even cancer chemotherapy are high-risk procedures due to the risk of infection of these microbes

Actinomycete Bacterial Strains

Many strains of actinomycetes were isolated form the acacia plant in which the ants lived. A few among these were selected for gene sequencing. Out of all the strains that were sequenced, the research team found that there was

• A specific strain of actinomycetes that produced antibiotic compounds with the ability to fight other diseases in the initial tests that were conducted.

Dr. Hutchings further stated that the formicamycins that were tested against the isolates of vancomycin-resistant Enteroccocus faecium and methicillin resistant Staphylococcus aureus were found to be very potent against these organisms.

Validation of the Result

The tests were repeated by growing the strains in very low and sub-inhibitory concentrations of formicamycins for 20 generations. The research team found no signs of higher level of resistance to the newly identified antibiotics.

Dr.Wilkinson from John Innes Centre said that the findings of the study signify the importance of identifying newer territories for effective antibiotics. The latest advancements in sequencing and genomic editing tools could be used to identify the unidentified species of bacteria that produce natural antibiotics. This, according to the professor, will be precious in the fight against antibiotic resistant bacteria.

There is an urgent need to identify solutions for antibiotic resistant bacterial strains as they can lead to serious health complications due to uncontrolled spread. The newly discovered antibiotic promises to control the spread of these microbes, offering hope to many people at high risk.

References:

1. Zhiwei Qin, John T Munnoch, Rebecca Devine, Neil A Holmes, Ryan Seipke, Karl A Wilkinson, Barrie Wilkinson, Matthew Hutchings. Formicamycins, antibacterial polyketides produced by Streptomyces formicae isolated from African Tetraponera plant-ants. Chem. Sci., 2017; DOI: 10.1039/C6SC04265A
2. Antimicrobial resistance - (http://www.who.int/mediacentre/factsheets/fs194/en/)

Source-Medindia