IMPENDING CATASTROPHE
Pan European Networks: Science & Technology
06
169
Professor Bjorn Olsen, of the Department of Medical Sciences, Clinical
Microbiology and Infection Medicine at Uppsala University in Sweden, on
why antibiotic resistance in developing countries is of global concern
PROFILE
Bjorn Olsen
Professor
Department of Medical Sciences, Clinical
Microbiology & Infection Medicine
Uppsala University
tel: +46 18611 5661
G
lobally 300,000-500,000 tonnes of antibiotics are used
per year. Approximately one-third in human medicine and
two-thirds used as feed additive for domestic animals
and for plant protection. More than 50% of the consumed
antibiotics are released into the environment (water and soil) via
human and animal urine. Different types of antibiotic resistance
mechanisms, with abbreviations such as MRSA, VRE, ESBL, CTX-
M, NDM-1, TEM, SHV, qnr, are reported in human, domestic
animals, natural water reservoirs and wildlife.
This indicates that there may be a wide dissemination of resistant
bacteria and/or their genes coding for drug resistance in the
environment. The sources of antibiotic resistant bacteria in the
environment are likely to be places where antibiotics have been
extensively used or in the recipient of effluent water or manure.
From there bacteria/genes can spread through the environment
via carriers such as humans and animals and may cause clinical
infections in susceptible individuals.
ESBL (Extended Spectrum beta-lactamases) is a bacterial
resistance mechanism and has become a public health concern.
ESBL production confers resistance to cephalosporins, a very
important group of antibiotics used as the last line of treatment in
bacterial infections in humans. The ESBL mechanism CTX-M, for
instance, was reported for the first time in a patient in Germany
and has since then spread pandemically, including densely
populated developing countries like India, China, Nepal, Pakistan,
Kenya, Egypt, Vietnam and Bangladesh.
The new emerging NDM-1gene in
E. coli
and
Kl. pneumonia
named as a ‘superbug’ is resistant against virtually all classes of
antibiotics NDM-1 frequently reported from hospitals in India,
Bangladesh and Pakistan. After the emergence, the superbug
spread globally in humans as well as in the environment. More
dangerously, NDM-1 producing bacteria have been reported in
food-animals in China and in lakes in Vietnam. China, India and
Vietnam are exporters of sea food and fish to the European
Union. It can be concluded that, at any time, new and pan-
resistance genes could evolve in humans and/or the environment
from any region of the world and spread globally, including in the
developing countries where antibiotic usage is not restricted.
Many human-associated bacteria harbour antibiotic resistance
genes that have been inserted into genetic mobile elements that
are able to spread among water and soil bacteria. In such
systems, even non-pathogenic bacteria serve as reservoirs of
antibiotic resistance genes. In many developing countries, poor
management of hospital and agricultural waste remains one of
the leading causes of environmental dissemination of many
disease agents and multi-resistant bacteria.
In developing countries, recurrent epidemics of infectious
diseases, including antibiotic resistant bacteria, results in many
deaths especially among children. Health disparities between rich
and poor countries are very striking. High income countries are
victimised by this problem even though they have regulations of
antibiotic use and sufficient capabilities in their healthcare
systems. Therefore, no one is safe from this problem. Human
migration, trade, tourism, medical tourism and food import are
ways to transfer antibiotic resistance bacteria. Due to the global
economic policy and open access market, it is impossible to stop
the movement of humans and food.
Available scientific information does not allow proper assessment
of the human health risks associated with the occurrence of these
bacteria in different ecological niches from developing countries.
Thus, the roles of hospital and agriculture activities in the rapid
dissemination of antibiotic resistant bacteria are an important
area to be explored in developing countries.
So what can we do to avoid the medical catastrophe we have
ahead of us? New antibiotics and combinations of antibiotics are
probably not a sustainable or long-term solution. Since we are not
learning anything from history, we will probably overuse and
misuse any new antibiotic on the market.We need to decrease
the ‘resistome’, the body of resistance in Nature and society by
banning growth promoters in animal feed, reduce doses and
treatment times and implement efficient technology (e.g. ozone
treatment of water) at sewage plants that destroy antibiotics.
ANTIMICROBIAL RESISTANCE
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