The colonization of patients by Klebsiella and several other gram-negative bacteria was studied in a hospital urological ward over a period of six months. Before and during the survey there was no evidence of an outbreak of nosocomial infection and multi-drug resistant strains of Klebsiella were not isolated.

Klebsiella were biotyped by nine biochemical tests, which led to the detection of 66 biotypes spread uniformly throughout the survey period. This method of biotyping proved a useful epidemiological tool. The colonization rate of throats, hands, and faeces of patients increased after admission to the ward, especially when antibiotics were used. The effect of systemic antibiotics was greater than that of urinary antibiotics especially on throat and faeces carrier rates. Carrier rates for Klebsiella increased also after catheterization and operation – relationships which could well be multifactorial.

During the first two weeks after admission the proportion of antibiotic resistant strains of Klebsiella in carriers increased. The proportion of resistant strains amongst isolations from clinical infections was always greater than among strains isolated routinely from sites of carriage.

During a 6-month period an epidemiological survey of the carriage of Klebsiella was conducted in a hospital ward where no outbreak of nosocomial infection occurred. In this endemic situation the regular sampling of several sites on patients, members of the nursing staff, and the environment, and the biotyping of Klebsiella made it possible to analyse the patterns of transmission between sites. There was abundant evidence for striking transmission of Klebsiella between the throat, hands, and faeces of patients. Transmission between patients seemed to be mainly through hands. The role of nurses' hands in transmission was not evident from this survey, probably due to the relatively long interval (a week) between samplings. Through the hands of patients, wash stands and the surrounding floor were contaminated with Klebsiella. The biotyping of Klebsiella facilitated the epidemiological analysis of the results.

Klebsiellas are generally typed by the method of capsular serotyping but, although this is a reliable method, it is time consuming, requires the production of a large number of antisera and is not generally available. For this reason another method for typing klebsiellas was sought.

A bacteriocin typing method involving mitomycin C induction was developed and the cultural conditions giving optimum klebecin production and the best methods of testing the sensitivity of the organisms to klebecins were determined.

Of 190 klebsiella strains screened for bacteriocinogeny, only 68 (35·8%) produced klebecin and after calculation of similarity values by computer analysis, a typing set of 15 producers was selected. This typing set allowed over 96% of klebsiella strains to be typed and tests of the reproducibility of the method and the variability of typing patterns in natural populations of klebsiella indicated that results of acceptable accuracy could be obtained, while retaining good discrimination if two or more differences were required between patterns before they were regarded as distinct.

A complete set of capsular antisera were prepared, enabling the results obtained from klebecin typing to be compared with those from serotyping. There was generally close agreement between the results from the two typing methods and greater discrimination was obtained between similar strains when the two methods were combined. Klebecin typing and serotyping revealed relationships between strains from five outbreaks of infection, and strains of the same serotype from different hospitals could frequently be distinguished by their klebecin typing patterns.

Sera of 197 apparently well persons were tested for residual haemagglutination-inhibiting antibodies against live Hong Kong/68, A/FM/47 and A/PR/34 strains. Sera of 62 well persons, regularly exposed to contacts with swine, were tested against an inactivated A/New Jersey/76 antigen.

Those born some time before and during a certain influenza era showed a significantly greater proportion of homologous residual titres against the subtype prevailing in that influenza era, than those born after the termination of the same era.

In each of the seven age groups tested both the percentage of positives and the geometric mean titres were usually highest against the Hong Kong strain (representing the most recent era); the next highest were those against the FM1 strain and the lowest were those against the PR8 strain (representing the most distant of these three influenza eras).

The serological involvement of donors exposed to regular contacts with swine was relatively stronger against the New Jersey antigen than the response of other serum donors shown against the other three, more recent, prototypes of influenza virus A. The oldest age groups showed significantly lower antibody response against the PR8, FM1 and Hong Kong strains (but not against the New Jersey antigen) than the next one or two of the younger age groups.

Live attenuated influenza vaccine containing the recombinant of A/Victoria/3/75 with A/PR/8/34 virus was administered to healthy adults in a field trial aimed at evaluating protection provided by immunization. The study was designed to measure the effect of vaccination on absenteeism from respiratory disease during a natural influenza epidemic. A total of 2115 male employees of the public transport service of Rome volunteered to participate in the trial, 1050 and 1065 receiving vaccine and placebo respectively, in a randomized blind fashion. Vaccination procedure was completed by the end of December 1976. A small-sized outbreak of influenza, due to a viral strain antigenically homologous to the vaccine, occurred during the month of February 1977. Analysis of absenteeism data, classified according to medical certificate, indicated that morbidity from respiratory disease was reduced in vaccinees compared with controls during the epidemic month; the rate of increase of morbidity compared with that of the preceding month was then three times lower in vaccinees than in controls and the difference in absenteeism between the two groups greatly exceeded the ordinary fluctuation that was observed during non-epidemic periods.

The model was based on grasping a fabric-covered bottle contaminated with a strain of Staphylococcus saprophyticus, then grasping a sterile fabric-covered bottle and counting the organisms transferred. When the donor fabric was moist 10% of the available cells passed onto the hands, but this fell to 0·05% when the inoculum dried. Transfer from wet hands to the fabric amounted to 85%, but in the complete model only 0·06% of the available cells were transferred. The model was used to assess simple methods of degerming the hands. Washing the hands reduced transfer by 95%, while washing in 70% alcohol reduced transfer by 99·99%. Lesser procedures investigated included applying 0·2 ml of 80% ethanol to the hands, which reduced transfer by 93%.

Brucella abortus infection in the bitch, associated with an aborted bovine fetus, is described. Clinical signs were absent, but the organism was isolated from many sites in the body, including the urine, after death. The response of the dog to B. abortus infection and its possible role as a vector of the disease is discussed.

Swine Vesicular Disease virus (SVDV) did not survive drying at high relative humidities (r.h.) but there was little virus loss at low r.h.

Purified virus dried in films was inactivated by formaldehyde fumigation only at high r.h. Inactivation was also influenced by the suspending medium from which the virus was dried. Purified virus resuspended in distilled water and then dried, was rapidly killed, but that in tissue culture fluid survived.

Thirty-two different types of anaerobic bacteria isolated from chickens have been tested for anti-salmonella activity in vitro. Under the conditions of the test only Bacteroides hypermegas and a Bifidobacterium sp. were shown to inhibit the salmonellas and this was attributed to the production of volatile fatty acids (VFA's) coupled with a low pH. When these organisms were tested in newly hatched chicks no inhibition of s. typhimurium occurred. Possible explanations for this observation are considered.

The pH value and concentration of VFA's in the caecal material were determined in chicks from 0–84 days. In vitro tests with s. typhimurium indicated that, whilst the organism would be able to multiply at the pH and concentration of VFA's found during the first few days after hatching, the rapid increase inVFA concentration during the first 21 days would make this increasingly difficult. The significance of the developing caecal flora in relation to VFA production and pH is discussed.

Because certain feed additives are known to influence the carriage of salmonellas, the sensitivity of various caecal anaerobes to these compounds was determined in vitro, generally at 1, 10 and 100 μg/ml. The additives tested included flavomycin, furazolidone, nitrovin, tetracycline, tylosin, sulphaquinoxaline, virginiamycin and zinc bacitracin. All the organisms tested were inhibited by 100 μg/ml furazolidone; none were inhibited by 500 μg/ml sulphaquinoxaline.

Changes occurring in the VFA concentration, pH value and microflora of the caeca of chicks fed for 49 days or longer on a normal starter diet or the same diet containing 10 or 100 mg/kg nitrovin have been compared. When the chicks were fed on the diet containing 100 mg/kg nitrovin, the Gram-negative non-sporing anaerobes were eliminated as a significant part of the caecal flora. However, the VFA concentration combined with a low pH in chicks from 2 weeks onwards was still sufficient to inhibit salmonella multiplication. Other possibly interrelated factors which might lead to an increased salmonella carrier rate in the nitrovintreated chickens are discussed.

The behaviour of f2 coliphage during activated-sludge treatment was influenced by the temperature, flow-through-time, concentration of mixed liquor suspended solids and the virus load.

The most sensitive way to detect behavioural changes was to examine the regression coefficients for the rate of uptake or loss of virus by the mixed liquor solids. This type of analysis revealed, for instance, high values when the solids concentration was high and even greater values occured when high inocula were used. At high temperature the rate of loss of virus titre after inoculation had stopped was greater than the rate of uptake of virus during inoculation although in all other conditions uptake occurred at a greater rate than the loss of virus. The coefficients were relatively low when the flow rate was increased, when the temperature was low or when the inoculum was small.

The distribution of virus between the solids and liquid fractions of the mixed liquor varied somewhat for all conditions but was notably different when (a) the plant was incubated at 5 °C when there was much less virus in the solids fraction than usual, and (b) when the inoculum was low and a much higher proportion of virus was found in the solids.

The efficiency with which virus was removed across the plant was the least-sensitive determinant of viral behaviour and the value was about the same for most treatment conditions. However, low or high inocula did result in some increased or decreased removal of virus, respectively.

Porcine enterovirus type 2 or porcine adenovirus type 3 were seeded into samples of pig slurry, and a bovine enterovirus was seeded into cattle slurry, and samples of the slurry were aerated in the laboratory for 21 days. The viruses were inactivated more rapidly in the aerated slurry than in control slurry which was not aerated. The difference in inactivation rate was greatest for the porcine adenovirus and least for the bovine enterovirus. Inactivation of the porcine enterovirus in aerated distilled water and in aerated, autoclaved pig slurry proceeded at a similar rate as in the same materials which were not aerated. Ten samples of aerated slurry were collected from an aeration tank which received weekly additions of raw pig slurry which was sampled at the same times. Each sample yielded a porcine enterovirus after concentration with the polyelectrolyte PE-60, but in three comparative titrations the viral infectivity titre in concentrates of the raw slurry was at least 1000 times greater than in the aerated slurry. Porcine enterovirus type 2 and porcine adenovirus type 3, which were seeded into pig slurry, and a bovine enterovirus seeded into cattle slurry, were inactivated by treatment of the slurry with calcium hydroxide at pH 11·5. The inactivation rate was highest for the bovine enterovirus and lowest for the porcine adenovirus.

Antibiotic production by dermatophyte fungi has been demonstrated in vivo in the lesions of patients with dermatomycoses. Patients infected with antibiotic-producing strains more frequently carried cocci resistant to penicillin and other antibiotics than did patients infected with non-producer strains. The total bacterial load was less in lesions caused by producer fungi. In vitro studies demonstrated the selection of penicillin-resistant S. aureus from mixed populations of resistant and sensitive cells.

In a warfarin-resistant population of wild mice reared in the laboratory, a dominant gene for adiposity, Ad, was found to segregate. The onset of obesity is at 4–6 months, and adipose mice suffer from hyperinsulinaemia; the sexes differ in penetrance, males having greater penetrance then females. Linkage backcrosses show the gene to be situated on chromosome 7 with about 25% recombination with the closely linked warfarin-resistance genes War, and frizzy, fr. The finding of adipose in two other wild populations also carrying War is discussed as an ecological and physiological problem.

The indirect immunofluorescence technique has been used to titrate the specific immunoglobulins in 200 sera from 64 patients with varicella, and 195 sera from 67 patients with herpes zoster. IgG and IgM antibodies were detected in all patients with varicella, and IgA in 59 (92%). All three classes of antibody appeared 2–5 days after the onset of the rash, increased virtually simultaneously and reached maximum titres during the second and third weeks. IgG then declined slowly, but never became undetectable and was still present in five subjects who were retested after 2–4 years; it was present in 88 out of 100 healthy young adults and probably persists indefinitely after varicella. IgA and 1gM antibodies declined more rapidly and were not detected in specimens taken more than a year after the illness. IgA, however, may possibly persist in some cases since low titres were found in 8 out of 88 young adults who possessed IgG antibody and had presumably had varicella in the past. IgA responses were significantly weaker in children under the age of 6 years than in older children and adults.

Six out of 67 patients with zoster were tested at various times before the onset of the rash: IgG antibody was detected in all. IgG was present in all sera taken after the onset of the rash, increased rapidly after 2–5 days, reached maximum titres during the second and third weeks and then declined slowly. IgA antibody was detected in 66 patients (99%) and IgM in 52 (78%); both types of antibody followed transient courses, as in varicella.

Maximum titres of IgG and complement-fixing antibodies were greater after zoster than after varicella, but the differences were not significant. IgA and IgM titres in young adults with zoster were significantly lower than in older patients, and also lower than in young adults with varicella.

Increases in varicella-zoster antibody in patients with herpes simplex virus infections consisted mainly of IgG, sometimes IgA, but never IgM.

In a factual report of this kind something must be said about the financial resources of the Institution, if only to show how handicapped a research laboratory is whose income is below that required for its proper functioning; and at the same time how much can be done by men of vision and determination in the most difficult and disheartening circumstances.