Staphylococcal infection resistant to chloramphenicol, erythromycin, and novobiocin; effect of antibiotic combinations on the emergence of resistant strains

The emergence of antibiotic resistance: myths and facts in clinical practice

Selection pressure, caused by the use of antibiotics--especially in hospitals--is the main factor responsible for the emergence of antibiotic-resistant bacteria. Resistance can arise endogenously by mutation (one-step, as found for Mycobacterium tuberculosis to rifampicin, or multi-step, as in gonococci to benzylpenicillin), or exogenously by transfer of R-factors. Mechanisms of resistance may involve a decrease in permeability, chemical modification of the antibiotic, or a change in the affinity of the target site. There are many misconceptions concerning the incidence, nature and spread of antibiotic resistance, and some of the most important of these are discussed. The emergence and spread of resistance can be controlled by adhering to antibiotic policies and by preventing or controlling outbreaks of infection. The importance of resistant organisms can be diminished by the development of new antibiotic agents, preferably containing new chemical entities.

Yearly incidence of penicillin-resistant staphylococci in man since 1942

For this study of the year-by-year change in the incidence of carriage of or infection by penicillin-resistant, coagulase-positive or haemolytic staphylococci in man, 248 contributions to the medical literature have been analysed and grouped under three main headings: people in hospitals, people with clinical signs attending out-patients' wards or doctors' surgeries, and people not currently receiving medical care.This analysis shows that there has been a steady increase in resistant strains among persons of the first group from 1942 to 1955, followed by a slight decrease to 1959, possibly owing to more discriminating use of penicillin. A steady increase was found in the other two groups from 1942 to 1959, the rate of increase being more pronounced among the group with clinical signs.The authors draw attention to the possible influence of the ingestion of penicillin with food on the incidence of resistant strains; the occurrence of such strains in certain foods; and the need for standardized techniques for sampling, for testing for staphylococci and for determining resistance.

A CASE of rheumatoid arthritis demonstrated at the Postgraduate Medical School of London

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Staphylococcal Infections of the Heart

The basic problems of staphylococcal infections do not seem near to solution. Possibly an effective and safe antibiotic will be found to which resistant, pathogenic staphylococcal mutants will not appeal. This may, not be an overly sanguine hope. Had it not been for the ability of the staphylococcus to synthesize penicillinase, this goal would have been achieved already, for staphylococcal mutants pathogenic to man and intrinsically resistant to penicillin (i.e., without the production of penicillinase) have not been reported. Even with better antibiotics grave problems would remain, however, for the staphylococcus often inflicts severe or even irremediable damage, especially in the heart, before the disease can be diagnosed.

Prevention is the crucial problem. Refinements in isolation technics and hospital sanitation may improve the protection of the patient in the operating room and the newborn infant in the nursery. Nevertheless, the hard core of infections in debilitated or otherwise susceptible medical patients will probably remain. To help them it will be necessary to learn to restore the mechanisms of normal host resistance that have been depleted by disease.