MONTREAL-The rising worldwide incidence of microbial resistance
stems from a wide variety of causes and does not reflect a single
global trend or etiology, Prof. Dr. Bernd Wiedemann, University
of Bonn, Germany, said at a plenary session of the 19th International
Congress of Chemotherapy.
Although it may be tempting to oversimplify the situation and
pin the blame on an overall cause, such as the misuse, overuse,
or inappropriate use of antibiotics, Dr. Wiedemann claims that
local patterns of resistance arise from specific etiologies and
must therefore be attacked singly.
One possible cause of increased resistance, for example, may be
traced to medical advances, such as organ transplantation and
cancer chemotherapy, that have paradoxically resulted in patients
who are sicker and more vulnerable to infection with resistant
Although resistance to antibiotics has been reported in many areas
of the world, Dr. Wiedemann said that these reports are based
on highly variable standards. Comparisons are virtually meaningless
in the face of different testing methods, breakpoints, surveillance
techniques, and government regulations.
Establishing microbiologic standards is important, Dr. Wiedemann
said, since "good epidemiology" is necessary to really
understand global patterns and begin to devise preventive strategies.
He noted that specific migrations of resistant bacterial clones
around the world have been documented. A resistant Streptococcus
pneumoniae was traced, for instance, from South Africa to
Europe and the United States, while a gentamicin-resistant Pseudomonas
aeruginosa traversed the globe eastward, also arising in South
Africa, but spreading to Israel, Thailand, and Singapore.
Dr. Wiedemann said that some trends bear watching because of their
potential impact on worldwide public health. The rising incidence
of resistant tuberculosis in drug addicts, he said, may eventually
represent a serious problem in many countries, as might methicillin-resistant
staphylococci, vancomycin-resistant enterococci, penicillin- and
tetracycline-resistant gonococci, and multiresistant Enterobacteriaceae