Several studies on our meats like chicken (both imported and local), beef, mutton and frozen burgers have found an alarmingly high incidence of antibiotic-resistant bacteria in them. Eating foods contaminated with such bacteria can cause life-threatening complications as the treatment of such cases may be difficult.
The indiscriminate use of antibiotics in animal feeds has caused the spread of antibiotic-resistant bacteria in farm animals. The spread of such bacteria in our meats is alarming and poses a serious health threat to consumers.
In a study carried out by the Department of Veterinary Services (DVS) in 2012, half of the domestic chickens were resistant to ampicillin, sulphonamide and tetracycline. The situation was worse with imported chicken: 87% ampicillin-resistant, 75% nalidixis acid-resistant, and 50% streptomycin- and sulphonamide-resistant.
The study also found 13.5% Tetracycline-resistant Salmonella; 5.4% Polymixin B and Erythromycin-resistant Salmonella and 2.7% Chloramphenicol, Penicillin G and Trimethoprim-resistant Salmonella in local chicken.
Food samples such as beef, mutton and chicken had antibiotic-resistant Salmonella. About 6.28% of the resistant Salmonella was isolated from imported products (44.2% beef and 18.6% chicken).
Salmonella causes diarrhoea (sometimes bloody), fever, and abdominal cramps. Resistant infections are more severe and have higher hospitalisation rates. Salmonella is showing resistance to more classes of antibiotics and is a serious public health threat.
In another study of live chickens sold at wet markets in Selangor, of the 90 chickens examined 68 (75.6%) were positive for Campylobacter. The most frequently observed resistance was to cephalothin (95.5%) followed by tetracycline (80.8%), erythromycin (51.4%), enrofloxacon (42.4%) and gentamicin (24.4%). Multidrug resistance (resistant to three or more antibiotics) was detected in 35.3% isolates (bacteria samples).
Like Salmonella, Campylobacter spreads from animals to people through contaminated food, especially raw or undercooked chicken. It causes diarrhoea (often bloody), fever and abdominal cramps, and sometimes causes serious complications such as temporary paralysis, and even death. Resistant Salmonella, Campylobacter and E.Coli infections have spread worldwide through travel and food trade.
In 2005, the USFDA withdrew approval of fluoroquinolones used in poultry (currently used in Malaysia) as this class of antibiotics causes resistant Campylobacter in poultry which are transferred to humans and may cause fluoraquinolone resistant Campylobacter infections to develop in humans.
In addition, local researchers also found the presence of multidrug-resistant strains of Listeria monocytogenes bacteria in frozen burger patties taken from supermarkets and other retail shops in the country.
Commonly found in raw foods, L. Monocytogenes can cause listeriosis. Common symptoms include gastrointestinal upset, headaches, fever and in severe cases, brain infection and or blood poisoning.
This study examined the susceptibility of L. Monocytogenes isolated from raw beef, chicken and vegetarian patties to 11 different antibiotics. 28 out of 41 bacteria samples were resistant to at least one and 19 were resistant to at least two antibiotics. Tetracycline, followed by erythromycin resistance, were the most common forms of resistance.
Antibiotics widely used in animal feeds
In livestock production, antibiotics are given to animals for a number of different reasons: treatment, prevention of disease and primarily growth promotion. Antibiotics are routinely added to animal feed or their drinking water. Antibiotics that are used as growth promoters are generally not even considered as drugs and are either not licensed or licensed solely as feed additives.
Most, if not all, of the antibiotics given to animals are medically used for humans. According to the World Health Organization (WHO), use of antibiotics in animal husbandry is generally not based on sound scientific principles.
In Malaysia, there are currently 97 antibiotic drugs registered for use. Most of these registered drugs are used in poultry and pig farms, less in cattle and goat farms. More than half of the antibiotics (active ingredient) registered with the Ministry of Health for food animals are not recommended for veterinary use by the WHO.
It can be seen that antibiotics are widely used in food-producing animals and this contributes to the emergence of antibiotic-resistant bacteria in these animals, which are of particular concern because these animals serve as carriers.
Marketing and promotional practices of antibiotics for therapeutic, proplylactic or growth promoter uses in animals by industry influence the prescribing patterns and behaviour of veterinarians, feed producers and farmers.
Resistant bacteria can contaminate the foods that come from those animals and people who consume these foods can develop antibiotic-resistant infections. There is now increasing evidence linking newly emerging resistant bacteria in animals being transmitted to humans mainly through meat and other food of animal origin or through direct contact with farm animals.
Food borne disease causing bacteria like Salmonella and Campylobacter have become resistant to classic treatment in humans as a result of the use of certain antibiotics in agriculture.
In the most recent tragedy in the first week of October, four people died and 60 others were hospitalised after eating contaminated food during a wedding feast in Kedah. The Health Department has singled out the chicken dish as the possible cause of food poisoning from Salmonella contamination (New Straits Times, 2 October 2013).
Antibiotics in food animals also leads to transfer of resistance genes which could be passed from animals to humans via harmless bacteria in food products and the resistant genes could then be transferred to disease causing bacteria in the human gut. The presence of similar vancomycin and cephalosporin resistant genes in both human and animal bacteria supports this view.
Because of the link between antibiotic use in food-producing animals and the occurrence of antibiotic-resistant infections in humans, antibiotics should be used in food producing animals only under veterinary supervision. According to the US Centers for Disease Control and Prevention antibiotics should only be used to manage and treat infections for animals.
It is clear the high incidence of antibiotic resistant bacteria in our meats that there are problems with the Livestock Farm Practices Scheme (SALT) which is to ensure that farms practising Good Animal Husbandry Practices (GAHP) produce safe and wholesome food of good quality, in sustainable and environmentally friendly conditions.
SALT certification is awarded to farms that meet criteria of GAHP, Animal Health Management, Bio-security, good infrastructure and prudent use of drugs. The certification scheme covers all types of livestock i.e. beef cattle, dairy cattle, broiler chicken, layer chicken, breeder chicken, deer, goat, sheep and pig.
Yet more than half of the domestic chicken harvested from the SALT certified farm in the DVS study were resistant to three classes of antibiotics i.e. ampicillin, sulphonamide and tetracycline. The situation was worse with imported chicken, as noted above.
Urgent and strong measures needed
There are clear indications that some SALT certified farms are unable to meet Good Animal Husbandry Practices. It is unclear if the causes are lapses in hygiene standards, imprudent use of drugs or lack of the required infrastructure. The fact that imported meat products have shown higher percentages of resistant strains of Salmonella points to lapses in monitoring and enforcement.
In view of the above, CAP urges the Ministries of Health and Agriculture to:
• Ban antibiotic use in animal feeds in light of the EU ban on antibiotics in animal feed.
• Create a national system to monitor antibiotic use in food animals. This includes actions to improve and refine the collection of data on antibiotic use in the country. Quantities and classes of antibiotics used in food animals according to animal species need to be documented. This is necessary for risk analysis, interpreting resistance surveillance data and to assess the impact of interventions to promote prudent use;
• Monitor resistance and track changes in antibiotic resistance through on going surveillance at local, state and national levels. This will identify emerging health problems so that timely corrective action to protect human health is taken;
• The containment of antibiotic resistance must be made a national priority. There is a need to create a national intersectoral body or task force comprising healthcare professionals, veterinarians, academics, agricultural scientists, consumers, the media, to raise awareness about antimicrobial resistance (AMR), prioritise research, collect data, recommend policy measures to contain AMR eg formulating principles for a new Animal Health Law;
• Develop guidelines for veterinarians to reduce the overuse and misuse of antibiotics in food animals;
• Provide education and training for livestock farmers on responsible use of antibiotics;
• Encourage good farming practices and best practices in disease control eg appropriate housing design for animals, good disinfection procedures, isolation of sick animals, use of vaccines and disease eradication programmes;
• Monitor imported meat products for antibiotic resistant contamination and the stringent enforcement of rules;
• Identify foods local and imported responsible for outbreaks of Salmonella infections and other food borne contamination;
• Monitor the spread of Salmonella among animals on farms to prevent their spread.
• Educate consumers and food workers about safe food handling practices and how to avoid Salmonella infections.
Press Statement - 10 January 2014
bull; Educate consumers and food workers about safe food handling practices and how to avoid Salmonella infections.