Ogston's coccus.

One hundred and thirty years ago, Alexander Ogston, a surgeon in Aberdeen, first saw micro-organisms in pus from an abscess, which he later called 'staphylococci'. He had already introduced 'Listerism' to Aberdeen, but wished to know more about the cause of infections. He extended Koch's work on 'traumatic wound infection in animals' to humans by a series of ingenious experiments. He used the most modern German microscopes and Koch's stains to study pus from abscesses, and was first to grow staphylococci in artificial cultures (hens' eggs). From 1878 to 1883 the laboratory in his garden was a major UK bacteriology research laboratory. Eventually he became Regius Professor of Surgery and had to 'leave research to others'.

Pioneers in infection control: John Snow, Henry Whitehead, the Broad Street pump, and the beginnings of geographical epidemiology.

John Snow was one of the founders of epidemiology. Already convinced of the value of pure water, he analysed the distribution of cholera cases in the 1848 epidemic in relation to the purity of the water supply in London. His hypothesis that cholera was spread by contaminated water was tested by the 'Broad Street' epidemic of 1854. Snow quickly traced the water used in the houses affected by cholera to the pump in Broad Street, and persuaded the parish council to remove the handle. The epidemic subsided. The council did not really believe Snow, so the curate, Henry Whitehead, set out to repeat Snow's work, albeit at a more leisurely pace as the epidemic had subsided. He located 700 deaths within a 250-yard radius and showed that use of water from the Broad Street pump was strongly correlated with death from cholera. This surprised him as he had drunk water from the pump himself during the outbreak. Thus 'geographical epidemiology' began, although it was some years before Snow's observations were generally accepted.

Pioneers in infection control-Joseph Lister.

Joseph Lister is one of the pioneers of Infection Control. Not only did he reduce the incidence of wound infection (usually fatal pre-Lister) by the introduction of antiseptic surgery using carbolic acid, but also he was the first to apply Pasteur's principles to humans. He showed that urine could be kept sterile after boiling in swan-necked flasks. He was the first person to isolate bacteria in pure culture (Bacillus lactis) using liquid cultures containing either Pasteur's solution of turnip infusion and a special syringe to dilute the inoculum and so can be considered a co-founder of medical microbiology with Koch, who later isolated bacteria on solid media. Lister also pioneered the use of catgut and rubber tubing for wound drainage. His life can be split into five periods: 1844-1853, London: first period; 1853-1860, Edinburgh: first period; 1860-1869, Glasgow (where he developed his 'antiseptic system'); 1869-1877, Edinburgh: second period; 1877-1900, London: second period.

A randomised trial of the durability of non-allergenic latex-free surgical gloves versus latex gloves.

A prospective randomised trial was performed to compare the robustness of a new non-latex surgical glove with a standard latex glove when worn by four general surgeons in a district general hospital. Gloves were retrieved after surgery and examined using the European Standard Test for punctures. The overall puncture rate was 10.1%, and there was no significant difference in the rates between the two types of glove, although punctures in the non-latex glove tended to be larger and more readily noted by the wearer. The increase in latex allergy among health care staff dictates the need for gloves made from other materials, which may also be useful for operations on latex-allergic patients.

A survey of starch particle counts in the hospital environment in relation to the use of powdered latex gloves.

As latex proteins, which cause latex hypersensitivity, can be found on starch particles and inhalation may be a route for sensitization, the presence of starch particles in hospital air was examined. The starch particles were demonstrated by immobilization onto cellulose acetate filters and staining with iodine. Rooms in which powdered latex gloves were used gave counts of up to > 3,667 particles per cubic meter of air. Starch particles were not found in the air in rooms where latex gloves were not used, and were highest in rooms with a high glove usage but no ventilation. A change to powder-free gloves significantly reduced the count of starch particles in the unventilated Accident/Emergency Department air. Use of powder-free gloves should be considered especially in unventilated areas in healthcare premises.

Airborne particles from latex gloves in the hospital environment.

Air sampling studies are described which show high levels of airborne starch powder contamination in areas where powdered latex gloves are used. Furthermore, culture of collected samples show a clear association between starch particles and bacterial colonies in an experimental system suggesting that airborne particles could act as a vector for pathogens in the hospital environment.

Penetration of meropenem into heart valve tissue.

Thirty-three patients requiring cardiac valve surgery were administered meropenem 1000 mg by a 5 to 10 min iv injection. Samples of blood, cardiac valve and atrial muscle tissue were removed at valvectomy and analysed for meropenem by high performance liquid chromatography (HPLC) with UV detection. The plasma concentrations observed in the samples from these patients were higher than those reported when meropenem 1000 mg was administered to healthy volunteers by 5 min iv injection. No clinical adverse events attributable to meropenem were reported and the single 1000 mg dose was well tolerated. The penetration of meropenem into cardiac muscle and valve tissue was rapid and in excess of that expected solely on the basis of distribution into extracellular fluid. The concentrations achieved in the tissues were in excess of the MICs of the pathogens commonly causing endocarditis.

Tests for the antibacterial activity of surgical glove material.

In-vitro and in-vivo models for testing the antibacterial activity of glove materials are described. The models were tested using four types of material: latex containing residual accelerator, latex treated by solvent-extraction to remove accelerator, material from hypo-allergenic accelerator-free gloves, and latex coated with quaternary ammonium compounds. In-vitro tests revealed two distinct types of antibacterial activity, one related to the accelerator which was slow-acting, and not neutralizable, and a second faster-acting neutralizable activity due to the quaternary ammonium compounds. The antiseptic coated material also showed antibacterial activity on human skin.

The clinical use of an antibiotic-bonded graft.

Attempts to produce an antibiotic-bonded prosthesis have failed owing to poor binding, drug toxicity or inadequate antimicrobial activity of the antibiotic particularly against Staphylococcus epidermidis. Rifampicin, with an ideal spectrum, but untested against slime-forming S. epidermidis has recently been shown to bind with carboxyl groups on gelatin-sealed Dacron. We therefore investigated rifampicin activity against 30 slime-forming adherent S. epidermidis colonies, isolated from 40 consecutive aortic graft recipients, and compared it with their methicillin, gentamicin, cefuroxime, tetracycline and vancomycin resistance patterns. The S. epidermidis colonies were highly sensitive to very low levels of rifampicin. Rifampicin was then bonded to gelatin-sealed Dacron aortic prostheses which were inserted in four patients at high risk of developing subsequent infection.

Hygienic hand disinfection tests in three laboratories.

A comparative study was made in three laboratories of a test for hygienic hand disinfection. Staphylococcus aureus was applied to the fingertips of a total of 74 volunteers (49 female and 25 male) and the effect of washing with three chlorhexidine preparations and one non-medicated soap was assessed after one and five applications. Fingertip inoculation is convenient and is a realistic representation of the in-use situation. Although significant differences were obtained between log10 reductions in test organisms using the same formulation in different centres, and different periods in the same centre, the maximum differences after a single application of a preparation were small, e.g. between centres 0.39 and between periods in the same centre 0.55, and after multiple applications the maximum difference between centres was 0.42 and between periods in the same centre it was 0.51. The differences between preparations were similar in all centres. This test compares well with other similar tests and products can be placed in rank order of effectiveness. It is concluded that this test, if carried out under the controlled conditions described, is sufficiently reproducible between laboratories and repeatable within laboratories to be used as a standard test.