Scientist says poor quality antibiotics, source of antimicrobial resistance in Ghana
Professor Christian Agyare, a pharmaceutical microbiologist, says poor quality antibiotics on the market is suspected as one of the major causes of antimicrobial resistance in Ghana.
Quoting from various studies and research undertaken by the Kwame Nkrumah University of Science and Technology (KNUST) College of Health Sciences and other scientists over the last decade, he said a biological assay on penicillins on some selected Ghanaian markets revealed a higher minimum inhibitory concentration (MIC) values.
This covered all evaluated penicillin samples compared to the reference samples, the pharmaceutical microbiologist disclosed.
Studies identified that out of the 54 samples evaluated, 61.1 per cent were within the British Pharmacopoiea (BP) and United States Pharmacopoeia (USP) monograph specifications.
Among the samples evaluated, amoxicillin showed a better quality of 82.8 per cent as compared to flucloxacillin (31.3 per cent) and cloxacillin (44.4 per cent).
Prof. Agyare, Provost of the College of Health Sciences, was delivering a paper on the topic: “Treating Non-Curable Infectious Diseases and Wounds with Natural Knowledge and Products”, at a Professorial Inaugural Lecture, organised by the KNUST, in Kumasi.
Antimicrobial resistance is the ability of microorganisms to persist or grow in the presence of drugs designed to inhibit or kill them.
This occurs when the bacteria and other microbes adapt and become less susceptible to the pharmacological treatment or intervention being offered.
The lecture looked at the various sources that could contribute to the development of antimicrobial resistance locally, and how natural products could be utilised to modulate antimicrobial resistance for improved therapeutic outcomes.
It dealt with antimicrobial use in aquaculture, animal husbandry and poultry, as well as the quality of selected antibiotics on the Ghanaian market.
On the antimicrobial use in animal husbandry and its implications, Prof. Agyare said many of the antibiotics used in animal husbandry were also essential medicines for use in humans.
“Residual levels of these antibiotics in animal, poultry and fish products, water bodies and the environment are potential sources for the development of microbial resistance,” he disclosed.
According to the Provost, a cross-sectional survey using questionnaires and semi-structured interviews was conducted among 400 poultry farms in the Ashanti, Brong-Ahafo and Greater Accra Regions.
Farmers, he said, reported the use of 35 different antimicrobial agents for management of various conditions such as Newcastle, fowl pox, coccidiosis and coryza infections in their farms.
“From these agents, 20 essential antibiotics belonging to 10 antibiotic classes were identified. The most frequently used antibiotics were tetracyclines (24.17 per cent), aminoglycosides (17.87 per cent), penicillin (16.51 per cent) and fluoroquinolones (10.55 per cent).
“Only 63 per cent of the farms completed the recommended duration of antibiotic course, 58 per cent of them indicated that they do follow the recommended withdrawal periods and 88 per cent of the farmers sought veterinary advice prior to antibiotic administration.” Prof. Agyare noted.
He said it was observed from the study that farmers had easy access to antibiotics and antibiotic-related information from veterinary offices, vet-chemical stores and mobile salesmen.
Touching on the resistance pattern of bacterial isolates of drinking water used in poultry production in the Ashanti Region, he said the study revealed that water used in poultry farms were sources of multi-drug resistant strains.
These include Escherichia coli, Salmonella typhi, Staphylococcus aureus and coagulase-negative staphylococci, which are responsible for various bacterial infections in humans and animals.
“Most of these isolates were resistant to cephalosporins and penicillin.” Prof. Agyare disclosed, stressing that almost 95 per cent of the bacterial isolates were multi-drug resistant.
It came to light that total coliforms and faecal Enterococci were present in 97 per cent and 56 per cent of the samples, respectively.
“From these findings, measures should be taken to make these various sources of water safe for use in animal husbandry as these waters are a potential source of pathogenic and resistant bacterial strains which can cause infections in the animals and farm workers,” the pharmaceutical biologist cautioned.
He said, prior to the identification of poor-quality antibiotics in the drug supply chain in the country, a study was conducted in three hospitals in Kumasi in the Ashanti Region.
The study identified antimicrobial resistance patterns in strains of Staphylococcus aureus, a resistance-challenging organism.
“A total of 109 Staphylococcus aureus isolates were obtained from wound and nose swabs of 300 patients.
“Vancomycin recorded the highest susceptibility of 74.1 per cent, followed by ceftriaxone with 67.6 per cent, erythromycin with 49.0 per cent, ampicillin with 47.0 per cent, and gentamicin with 44.4 per cent.
“Of the 109 Staphylococcus aureus isolated from the three hospitals, 32.1 per cent exhibited multiple drug resistance.” Prof. Agyare disclosed.
In a similar study carried out in some fish farms in the Ashanti Region, he said, there was varying resistance to more than 60 per cent of the antibiotics studied, including penicillins, tetracyclines, sulfonamides, macrolides, cephalosporins, quinolones and chloramphenicol.
“The bacteria isolated from fish samples exhibited multi-drug resistance although farmers reported no recent use of antibiotics on their farms, which was very worrying,” he said.
It is estimated that antimicrobial resistance causes around 700,000 deaths annually around the world, and all countries in the world are potentially affected.
The death toll could hit 10 million per annum by 2050, if the problem is not properly and adequately addressed, says the World Health Organisation (WHO).
Prof. Agyare described antimicrobial resistance as a global threat to humanity that must be addressed head-on.
“Efforts must be made to stringently control access to antimicrobial agents that could be a saviour of mankind from the microbial apocalypse through the combined effort of regulators, prescribers, pharmacies and dispensary outlets,” he advised.
“Regulatory bodies must intensify surveillance to ensure that antimicrobial products on the market are of the required standard,” he advised, saying there was the need for a well-defined policy direction to improve antimicrobial stewardship.