Antibiotic-resistant bacterial infections have been known from the time of genesis of antibiotics, and are a growing menace worldwide. This is posing a threat to the lives of thousands of patients. New antimicrobial agents are needed to combat this threat. Combination broad spectrum antibiotics are showing promising results in this scenario.
Antibiotics are natural substances derived from bacteria or fungi, which are critical in preventing the proliferation of other bacteria or pathogens. Chemotherapy using these antibiotics has been a main cause of increase in average life expectancy. However, disease-causing microbes that have become resistant to antibiotic therapy are an increasing health concern. Bacterial resistance is a consequence of the use, particularly the misuse, of antimicrobial medicines and develops when a micro-organism mutates or acquires a resistance gene.
The capability of certain bacteria to develop resistance to antibiotics, which are otherwise useful in speeding recovery from some illnesses, has been an important topic of discussion among the doctors, healthcare professionals and the general public for many years. Research is being conducted worldwide to find out the causes and solutions for this problem.
History of antibiotics devpt and emergence of antibiotic resistance
Sir Alexander Fleming in 1929 developed the first antibiotic, penicillin. Ernst Chain and Howard Florey in 1939 developed a method to isolate penicillin and used it to treat infections during Second World War. This discovery led to discovery of many other natural antibiotics. Penicillin became available in 1946, for treatment of bacterial infections, especially those caused by staphylococci and streptococci. New antibiotics were introduced in the late 1940s and early 1950s and the age of antibiotic came to full action.
The first signs of antibiotic resistance
Resistance to penicillin in some staphylococci strains was found almost immediately after its introduction in 1946. Similarly same was noted for streptomycin, chloramphenicol and tetracycline soon after their introduction in the late 1940s.
Consequences of antimicrobial resistance
As a result of bacterial resistance, treatment of human infections are compromised, elders and children are exposed to serious complications, the length of treatment and the recovery period is extended with more visits to doctors, and as a result of all these there is a chance of prolonged hospital admission and also increased treatment cost.
Current scenario
In spite of the advancements in medical field with emerging of various diagnostic and treatment modalities, a patient can still lose his life from a life threatening infection due to multi-drug resistant bacteria. This rapidly emerging resistance to antibiotics among the pathogens is threatening the present and future medical advances. The extensive use of antibiotics in medicine and agriculture has increased the reservoir of resistance genes.
Currently, it is estimated that more than 70 per cent of the bacteria that cause hospital-acquired infections are resistant to at least one of the antibiotics used to treat them.
According to the Centers for Disease Control and Prevention (CDC), all significant bacterial infections are globally becoming resistant to the most preferred antibiotic. The CDC estimates that, every year, nearly two million people in the United States acquire hospital-borne-infection, resulting in 90,000 deaths.
Although bacterial resistance is been known for a long time, today’s scenario differs from that of 10 years ago as the number of bacteria resistant to many different antibiotics has increased, 10-fold or more. Even the approved new drugs are facing resistance.
Rising resistance to existing antibiotics and a dearth of new antibiotics under development is threatening public health, according to the Infectious Diseases Society of America, FDA.
Research
Around 352 clinical trials on bacterial resistant antibiotics have been conducted worldwide among which 103 studies are ongoing currently using various groups of antimicrobials. In India two studies are being conducted involving various broad spectrum antibiotic combinations of penicillin, cephalosporin and nitroimidazole groups.
Fight against resistance
A task force Co-chaired by the CDC, the FDA, and the National Institutes of Health, to tackle the problem of antimicrobial resistance was formed in 1999 by 10 federal agencies and departments. The success of the Public Health Action Plan to Combat Antimicrobial Resistance depends on the co-operation of many entities, such as state and local health agencies, universities, professional societies, pharmaceutical companies, health care professionals, agricultural producers and the public.
The two most important things to be done to combat this problem are: facilitate the development of new antimicrobial therapy while at the same time preserve the usefulness of current and new drugs.
FDA is also encouraging the development of new antibiotics, new classes of antibiotics and other antimicrobials.
Bacterial resistance is the ability of bacteria, fungi, parasites, and viruses to grow, even in the presence of a drug that would normally kill it or limit it's growth. Drug resistance is a, particularly seen in infections such as MRSA (Methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant enterococci), tuberculosis, HIV, STDs, gonorrhea, flu, pneumonia, malaria, E. coli, salmonella, Campylobacter
Upcoming product
Sulbactomax a novel antibiotic, is a combination of beta-lactam cephalosporin (ceftriaxone sodium), Beta-lactamase inhibitor penicillin (sulbactamesodium )in 2:1 ratio.
Pre-clinical studies including acute toxicity, sub acute toxicity, intravenous, para venous toxicities as per OECD guidelines, pharmacokinetic studies, efficacy and safety studies established through a series of microbiological studies carried out as per NCCLS guidelines, along with comparative, randomized phase-III multi-centric clinical studies on 290 patients as per GCP guidelines have been conducted.
A multi-centric, Phase III, clinical trial on Sulbactomax was conducted on 594 patients and completed on additional indications like Skin and skin structure infections, Otitis media, Surgical infections, Bone and Joint infections and Septicemia. Sulbactomax is indicated for the treatment of infections of respiratory tract complicated and uncomplicated urinary tract infections and other serious infections caused by beta-lactamse producing ceftriaxone resistant bacterial strains.
Conclusion
The emergence of drug-resistant pathogens is not new or unexpected issue. This antimicrobial resistance can be decreased by using appropriate medication and by avoiding their overuse or misuse. This problem can be combated by encouraging the development of new antimicrobial drugs along with preserving the usefulness of current and new drugs. Combination antibiotics such as Sulbactomox is a boon in saving many lives from antibiotic resistance bacterial infections.
Authors are working with G7 Synergon Pvt Ltd,
Life Science Consulting Group, Bangalore.