A food-poisoning outbreak caused by Bacillus cereus occurred in a Finnish industrial plant in January 1975. Eighteen of the 36 persons who ate a lunch including boiled rice, meat and vegetables became ill. The disease pattern was similar to previously reported short incubation time B. cereus food-poisonings associated with cooked rice. The median incubation time was two hours, the main symptoms being nausea, abdominal pain and vomiting. Rice and certain seasonings were the contaminated raw materials. Gas chromatographic fatty acid analysis of a bacterial cell was used as a diagnostic method as well as to identify a certain strain of B. cereus.

Extracts of 3 soya bean preparations, used commercially in certain countries to replace part of the meat in popular meat products, were made by treatment with (i) sodium dodecyl sulphate, (ii) Triton-X100 or (iii) n–Butanol. Similar extracts were made from beef and pork.

All extracts were examined by electrophoretic and immunological techniques. Stained polyacrylamide gels revealed distinctive protein bands after electrophoresis. The migration rates of corresponding bands differed between beef and pork extracts. However, the migration rates of vegetable bands revealed certain similarities, but differed very greatly from those of animal origin. Characteristic fast-migrating S-bands were distinguishable only in extracts of vegetable protein. Immunodiffusion tests, using antisera produced in rabbits against each extract, revealed varying degrees of similarity between extracts of vegetable origin, but the antisera were specific for either vegetable or animal protein.

An area of the laboratory bench on which slide agglutinations were performed in the diagnosis of salmonella and shigella infection was examined for these organisms. Impression plates and broth-moistened swabs were used for sampling. Both techniques gave satisfactory results, but the contact plates provided positive results a day earlier than the swabs. Suitable precautions to minimize contamination of the bench surface are discussed.

This work is concerned with the cleaning and disinfection by heat of stainless-steel and polypropylene bedpans, which had been soiled with either a biological contaminant, human serum albumin (HSA) labelled with technetium-99m 99m(Tc), or a bacteriological contaminant, streptococcus faecalis mixed with Tc-labelled HSA. Results of cleaning and disinfection achieved with a Test Machine and those achieved by procedures adopted in eight different wards of a general hospital are reported. Bedpan washers installed in wards were found to be less efficient than the Test Machine, at least partly because of inadequate maintenance. Stainless-steel and polypropylene bedpans gave essentially the same results.

The report investigates the variation in results noticed when testing iodophor disinfectants in the presence of a 5% (w/v) yeast suspension.

It was found that these variations were not related to individual iodophor formulations but bore a direct relationship with the storage time of the prepared yeast suspension.

A plastic, mechanically ventilated source isolator with filters in the air effluent was designed to enable infected patients to be nursed and treated in a general ward or to be transported without risk to staff or other contacts.

Two models of isolator were developed. Their potential value was tested by the challenge of heavy dispersal, inside the isolator, of bacteria (a) from patients with burns, during the change of dressings, (b) from contaminated bedding during simulated bed-making, and (c) from the dispersal of a suspension of Bacillus subtilis var. globigii.

Sampling of air by slit samplers outside the isolator and, in comparable control patients, from the air of the room in which dressings were changed, showed consistently lower counts of bacteria and of Staph. aureus during dressings when the isolator was used; on removal of the isolator canopy there was, in some experiments, a considerable increase in airborne bacteria, due to residual bacteria in the isolator or to the re-dispersal of bacteria which settled on the patient and his bedding during the dressing.

Simultaneous sampling with slit samplers inside and outside the isolator during and after bed-making or dispersal of B. subtilis var. globigii showed an almost complete protection of the air outside the isolator against contamination by bacteria released inside the isolator.

The effect of operating clothing on the dispersal of bacterial particles from the wearers was studied in a dispersal chamber. A comparison was made of six gowns as well as four types of trousers. The gowns were of three basic types, namely a conventional cotton type, disposable types made of non-woven fabric and those of the total-body exhaust system (Charnley type). The dispersal chamber could simulate conditions as expected both in down-flow unidirectional ultra-clean systems and in a conventional turbulent plenum-ventilated system. It was found that the disposable gowns would reduce the dispersal rate by about 30% in the simulated conventionally ventilated system and about 65% in the laminar flow system. The total-body exhaust system (Charnley) would reduce the count by 10-fold in the conventional ventilated system and by 66-fold in the laminar-flow system.

The poor performance of the gowns in conventionally ventilated systems was caused by the dispersal of bacterial particles from underneath the gown (about 80%). This was not reduced by the disposable gown and only partially by the Charnley type. This small drop would be further decreased in a conventionally ventilated operating-room as only scrubbed staff would wear the gown. In order to overcome this poor performance in conventionally ventilated operating-rooms impervious trousers would be required. Four types were studied and it was demonstrated that those made either from Ventile or non-woven fabric would reduce the bacterial dispersion fourfold.

As these tests had been carried out in an artificial environment checks were carried out in the unidirectional-flow operating-room during total-hip arthroplasty. This was done by comparing conventional cotton gowns with non-woven gowns and total-body exhaust gowns. The results showed good correlation between the operating room and the chamber with the non-woven fabric gown but the total-body exhaust system did not perform as well in the operating room (12-fold compared to 66-fold) the difference being possibly due to the contribution from the patient. However, as this comparison was that which would be most open to influence from other variables confidence could be placed on the chamber test results.

Values were also obtained for the total number of bacterial particles dispersed by persons during a standard exercise wearing different clothing. This count was dependent on the clothing worn but a median count of between 1000 and 1500 peatorial particlos/min. would be expected when conventional clothing was worn, with a range of between 300 and 19,000. This count could be reduced to about 100/min. if a total-body exhaust suit was worn (range 30–400).

After five months of total isolation a wintering party of seventeen British Antarctic Survey (BAS) personnel was inoculated under double blind conditions with placebo, or rhinovirus type 2 which had been propagated in tissue culture. The clinical and virological responses of these subjects were compared with those of volunteers in England who received a similar dose of the same strain. The virus used was apparently partly attenuated for man; at the dosage used its effects in England were similar to a smaller dose of an unattenuated strain, but in the Antarctic it caused relatively severe infections. Both the symptoms and the laboratory evidence of virus infection appeared to be more pronounced in the BAS subjects than in the volunteers in England who received the same challenge. In the former group the infection readily spread to those who were originally given placebo. In the BAS subjects serum antibody titres were well maintained during the isolation period but a significant fall in nasal immunoglobulin concentration was recorded during the 5 months of isolation after the virus challenge. Possible mechanisms for the increased sensitivity to rhinovirus of subjects who have been totally isolated in a small closed community are discussed.

The pathogenicity of two bovine field strains of virus for indigenous goats was examined in the laboratory. The goats failed to develop clinical disease or become virus carriers although the majority showed a definite immune response. A field survey in a foot-and-mouth disease enzootic area showed that the indigenous sheep and goat populations were frequently exposed to infection as evidenced by a high proportion of sero-positive animals but the incidence of virus carriers was very low in goats and no carriers were detected in sheep.

The serotypes of 13,139 strains of Escherichia coli isolated from humans were compared with the serotypes of 1076 strains isolated from animals. 689 of these strains were isolated from fresh cow-pats on 22 sites in England and Wales. 708 different O/H combinations were found. Of these, 520 were found in human strains only, 130 from animal strains only and 58 O/H serotypes from humans and animals. Approximately half of the animal strains could not be typed with the full set of sera used.

Sixty three samples of dairy creamery effluent were examined for the presence of mycobacteria. Thirty two strains were isolated from 27 samples. These were classified as follows: M. fortuitum (13), M. peregrinum (6), M. gordonae (5), M. marianum (scrofulaceum) (4), unidentified (4).

Ten strains, representative of the groups isolated, were tested for their effect on experimental animals. None were pathogenic for guinea pigs or mice but a number produced a minimal amount of skin sensitization in guinea pigs to avian and mammalian tuberculin.

An outbreak of shigellosis due to Shigella sonnei, is reported in laboratory maintained marmosets (Callithrix jacchus) and tamarins (Saguinus nigricollis). The clinical signs and pathological lesions are described and the microbiological findings discussed. Control of the disease was based upon hygiene and antibiotic therapy and the consequences of this approach are described in detail.

Defatting milk for the Brucella abortus whey agglutination test with chloroform caused some reduction in the titre in i.u./ml. in 42 of 57 samples and this reduction exceeded 50% in seven. Though this procedure will probably rarely affect the final interpretation of the test defatting the milk by centrifugation is preferred.

Fifteen healthy volunteers were given three weekly subcutaneous injections of a new polyvalent Pseudomonas aeruginosa vaccine (PEV-01). Four doses – 1·0 RHD (manufacturer's recommended human dose), 0·75 RHD, 0·5 RHD and 0·1 RHD – were used in separate groups of volunteers. Blood samples taken before each of the injections and one taken 7 days after the last injection were examined for immune response to the vaccine and for possible adverse clinical, biochemical and haematological effects.

Raised titres of antibody in serum of volunteers given 0·5–1·0 RHD vaccine were shown, often by the seventh day, in passive haemagglutination tests against all of the 16 serotypes of Ps. aeruginosa represented in the vaccine; serum from volunteers who received 0·1 RHD usually showed a reduced antibody titre. Tests of mouse protection by serum against intraperitoneal challenge with Ps. aeruginosa P14 showed increased titres of mouse protective antibody in the blood of volunteers given 1·0, 0·75 or 0·5 RHD of vaccine but a reduced mouse-protective titre in two out of three sera from volunteers given 0·1 RHD vaccine. There was a suggestion of enhanced phagocytic ingestion and intracellular killing of two strains of Ps. aeruginosa by the blood of vaccinated volunteers, and more definite enhancement of ingestion of inert latex particles, which were less well ingested than were the bacterial cells by phagocytes from unvaccinated volunteers.

Apart from slight or moderate local reactions and a transient rise of temperature in some volunteers, there were no clinical, biochemical or haematological abnormalities in the vaccinated volunteers.

Normal non-irradiated McCoy cell cultures provide a sensitive and reproducible method for the isolation of oculo-genital strains of chlamydia A directly from human secretions and for laboratory studies with these agents. Since September 1973, chlamydia have been isolated from 175 of 562 women (32·1%) attending venereal disease clinics. Freshly isolated and low passage strains have been used to determine the importance of centrifugation, constitution and pH of the tissue culture medium, and the temperature of incubation in controlling the efficiency of plating in the method.

The well known cryoprotective additives glucose, sucrose, glycerol, dimethyl sulphoxide, polyvinylpyrrolidone, dextran and ammonium acetate have been found to prevent inactivation of T4Bo phage frozen in sodium bromide solutions. Their protective effects in this experimental system could not be accounted for by a colligative mechanism. It is proposed that they may act by modifying the structure of the unfrozen aqueous phase rather than by direct interaction with the phage.

A single intranasal dose of 107.0 EID50 recombinant WRL 105 strain live attenuated influenza vaccine was administered intranasally to 193 volunteers either as nose drops or by one of three spray devices which produced sprays of differing physical characteristics. In volunteers with homologous haemagglutinating inhibiting antibody titres of ⋜ 20 before vaccination, seroconversion rates varied widely from 80% following the administration of drops to 71%, 57% and 28% with the three spray devices.

In the week following vaccination 16 (22%) of 74 volunteers who were found to show a fourfold or greater antibody response took analgesics to control symptoms in comparison with 4 (7%) of 58 volunteers who exhibited no sero-logical response to vaccination (P < 0.05). However, neither the occurrence of upper respiratory nor systemic symptoms were significantly different in these two groups and the degree of attenuation of the recombinant WRL 105 strain appears to be acceptable for future use.

‘Mention of a trademark or a proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture, and does not imply its approval to the exclusion of other products that may also be suitable.’

Non-immunized, vaccinated, and recovered cattle were inoculated intranasally with various doses of foot-and-mouth disease virus. Samples of oesophageal-pharyngeal (OP) fluid were taken periodically for up to 7 days after inoculation and virus titres of these samples were plotted as pharyngeal virus growth curves.

In non-immunized cattle, the length of the lag period and of the growth period were inversely proportional to the dose of virus given. Maximum titres were observed when clinical signs were first detected. Three of the 10 cattle studied had virus growth rates that were lower than rates of others given the same dose of virus, and clinical signs appeared later than expected in these three cattle.

Cattle vaccinated with an inactivated virus oil-adjuvant vaccine had pharyngeal virus growth curves that were similar to those obtained from non-immunized cattle for 30 h. after inoculation. Titres of virus in OP fluid samples taken 2–7 days after inoculation were substantially lower in cattle with a high pre-exposure serum mouse protection index than titres from partly-immunized or non-immunized cattle.

Nine of 14 recovered cattle had detectable but reduced virus growth after intranasal inoculation with homologous virus. Five recovered cattle inoculated with heterologous virus reacted similarly to non-immunized animals.