Serum cholesterol in rabbits was elevated, by intravenous inoculation of 20 % Tween 80, to amounts thought to have been sufficient to support growth of Mycoplasma gallisepticum when 20 % of such serum was added to rabbit infusion broth.

However, better growth of the organism was obtained with a supplement of 5 % rabbit serum and commercial cholesterol. Investigation showed that normal rabbit serum may be inhibitory, which would explain these findings. The commercial cholesterol was not antigenic.

1. A bacteriological laboratory was provided in the medical departments of two passenger ships—a modern luxury liner cruising in the Mediterranean for 1 month and an older vessel, now out of commission, on a 3 months round voyage through the tropics. Galley hygiene in relation to gastro-enteritis was investigated on both ships.

2. 125 samples of water and iced water were examined. Samples of water chlorinated on the ships were usually satisfactory. Many port waters sampled from the barge or hosepipe were contaminated—some mildly, some profusely. A fault in an ice-making machine led to pollution of ice used for various purposes. Swimming-bath water was usually mildly polluted only; occasionally in the tropics when the baths were very popular the count rose to 1600 Esch. coli per 100 ml.

3. Thirty-five samples of milk, ice-cream and churn washings were examined. English liquid pasteurized milk stored in the cold gave satisfactory results, but the rehydrated dried milk used exclusively on the round voyage through the tropics and swabs from the apparatus used in its preparation were contaminated with Esch. coli. Ice-cream samples from ship I gave satisfactory results, and of two samples of ice-cream powder examined on ship II one was satisfactory and the other gave a poor result. Occasional churns which had been superficially cleaned but not sterilized had a high general and Esch. coli count.

4. 189 samples of food were examined, twenty-two for general and coliform counts only. Results were variable according to foodstuff and atmospheric temperature. Some cold cooked meatstuffs gave low counts and absence of coliform bacilli in 1/10 g.; others had plate counts of 300,000 to 25 million per gram with Esch. coli in 1/1000 dilution, e.g. crayfish ready for the table. Salmonellae were not found in any samples but occasionally small numbers of coagulase-positive staphylococci and non-haemolytic Cl. welchii were isolated.

5. Sixteen samples of imitation cream and washings from savoy bags were examined. Samples from freshly opened cans of cream gave satisfactory results. In whipped cream and in cream from cakes and sweets, Esch. coli was found in 1/1000 dilutions, and rinsings from savoy bags in use gave probable numbers of Esch. coli of 18,000 + / 100 ml. Counts were still high after the bags had been washed and dried and they were far from sterile even after ‘boiling’ and drying.

6. Twenty-three samples of wash water from salad vegetables and fruit had high counts of Esch. coli. After these articles had been washed in water containing 80 p.p.m. sodium hypochiorite, coliform organisms were not found in 100 ml. of water. Potassium permanganate was considered to be of doubtful value. The results of laboratory experiments to confirm the concentration of hypochiorite and time necessary to destroy Esch. coli on lettuce and watercress are shown in Tables 3 and 4.

7. Results from forty-four samples of wash and rinse waters from dish-washing machines and one bowl showed that the temperatures were often too low; with temperatures above 50° C. coliform bacilli were absent in 1 ml. quantities, but waters at temperatures below 42° C. gave probable Esch. coli counts of 1800 + / 100 ml. The bacteriological condition of the crockery and cutlery varied according to the wash and rinse waters. Rinses from metal dish covers gave poor results, with 1800+ Esch. coli per 100 ml. of rinse and occasionally Cl. welchii and coagulase-positive staphylococci. Wash and rinse waters, with temperatures of 35°ndash;42° C. used for pots and pans gave probable Esch. coli counts of 1800 + /100 ml.

8. Rinse waters from twenty cloths used in the galleys, pantries and dining rooms were nearly all heavily contaminated with Esch. coli, with probable numbers of 18,000 + /100 ml.; these counts were reduced to negligible figures by soaking the cloths in chloride of lime.

9. Swabs were taken from thirty-eight cutting-boards and twenty-six surfaces of sinks, shelves and miscellaneous articles. Many boards were heavily contaminated, the probable number of Esch. coli being 18,000 + /100 ml. of diluent; lecithinase-positive clostridia were found also. The boards could be sterilized by brushing with a stout wire brush followed by chlorination.

Other surfaces, and swabs from various knives in the kitchen, including the blade of the slicing machine, frequently gave high counts of Esch. coli.

10. 329 swabs from nostrils and fingers of saloon and galley staffs yielded one cutlure of coagulase-positive staphylococci from 111 nasal swabs and three cultures of coagulase-positive staphylococci and seven of Esch. coli from 218 finger swabs from twenty-seven men.

11. Twenty-eight faecal specimens were examined from fifty-four cases of gastro-enteritis reported on the Mediterranean cruises; salmonellae were not found, but heat-resistant Cl. welchii was isolated from six samples (21%), and the clinical picture was that of Cl. welchii food poisoning.

12. 121 faeces samples from 137 patients with gastro-enteritis were examined chiefly for salmonellae and coagulase-positive staphylococci on the outward leg of the round voyage through the tropics. Salm. typhimurium was isolated from a clinical case and Cl. welchii from one typical case of food poisoning. On the return journey all samples were examined also for Cl. welchii; of thirty-five stool samples from thirty-five patients, six (17%) yielded lecithinase-positive clostridia; salmonellae were not found.

13. Heat-resistant strains of Cl. welchii were also isolated from two chopping-boards, a knife, cold beef, brawn, two wiping cloths, a dish cover, two samples of pie and corned beef.

The prevalence of antibodies against Entamoeba histolytica was studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture of Entamoeba histolytica HM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60538 samples supplied by the National Seroepidemiology Survey, antibodies were found in 4·49 % (4·32–;4·65% at 95 % confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1·25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country.

Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.

This study attempted to examine the relatedness between RAPD–PCR, PFGE and VcA VNTR results with those of conventional phage typing of V. cholerae strains and to evaluate VcA VNTR as an indispensable molecular-typing tool that accomplishes the urgent need for effective epidemiological surveillance. All the O1 El Tor strains were predominantly clustered into phage type T27 with the new phage-typing scheme. Using RAPD–PCR, a total of 69 O1 El Tor strains were grouped under 16 different electrophoretic patterns. A total of 33 pulsotypes were identified in these strains by PFGE. VcA VNTR revealed high VcA polymorphism in all V. cholerae strains incorporated in this study. Our results underline the considerable potential of VcA VNTR analysis as a tool for molecular typing of V. cholerae.

The characteristics of Gram-negative organisms and some of the underlying reasons for their adjuvant action with diphtheria toxoid are described.

The adjuvant effect was shown by an earlier production of antitoxin, with a maintained differential advantage over controls, but with the usual decline in titre with passage of time. The adjuvant effect only occurred with a primary stimulus. There was no adsorption between toxoid and vaccine and mixture of the two was not necessary, but the vaccine had to be given simultaneously with or within 24 hr. following injection of the toxoid. There was evidence for believing that these adjuvants decreased the minimal stimulating dose of antigen and caused hyperplasia of antibody-producing cells. No direct link could be found between the characteristic stress symptoms caused by lipopolysaccharides and their ability to enhance antibody formation.

Polyacrylamide gel electrophoresis of cell proteins was investigated as a possible typing method for Corynebacterium diphtheriae. A method was developed using stock strains which were representatives of the five gravis serotypes described by Robinson & Peeney (1936). This technique was then applied to recent isolates sent to our laboratory for identification.

(1) At present no public authority possesses legal power to deal with the question of the contamination of shellfish.

(2) It is not sufficient to test shellfish exposed for sale in a market or shop. These may have been contaminated subsequent to removal from the fishery; and multiplication of the contained bacteria may have taken place. The results of such analyses may lead to unjustifiable condemnation of a laying. It is essential that a topographical examination should be made and that samples for analysis should be taken from the laying itself.

(3) In the case of natural shellfish beds there is so much variability in the conditions with regard to the susceptiblity to pollution that a fairly large number of the animals must be examined. The labour of the analyses is therefore so great that the development of some simple routine test for faecal contamination is most desirable. Since most desirable. Since most natural shellfish layings are situated within the “sewage zone”, and therefore contain B. coli, quantitative results are essential.

(4) There are considerable differences in practial routine work in regard to the methods of isolation of intestinal organisms from shellfish; and aslo with respect to the number and nature of the reactions necessary for the identification of B. coli. It is desirable that some generally recognised series of tests should be uniformly adopted by bacteriologists engaged in such work. Further, different micro-organisms, possibly of varying degrees of significance as indicators of faecal contamination, may have been confused. There is possibly some variation in cultural characters in B. coli, and investigation of this variability is desirable. Investigation of the changes in cultural reactions undergone by intestinal organisms when entering the sea, or the tissues of marine shellfish, is also very desirable.

(5) Remedial measures other than the simple closure of a contaminated laying might be suggested. It is possible to subject the shellfish to treatment which will cause them to clean themselves of contained sewage bacteria. The source of the pollution may be removed; and sterilisation of the shellfish may be practised.

1. This paper reports the results obtained by the cultivation of the bacteria of ten batches each of ten mussels, 100 mussels in all, in lactose bile broth.

2. From these mussels 371 cultures of bacteria were obtained. 30·7 per cent, of these were not Gram-negative bacilli, 10·0 per cent. were Gram-negative bacilli which did not ferment lactose and glucose, 59·3 per cent. were coliform bacilli.

3. By reading the results in lactose bile broth after 24 hours' incubation, and by regarding as positive those tubes which show strong acid and good gas production the most reliable results were obtained. 93·0 per cent. of all typical, and 83·8 per cent. of all typical and atypical B. coli found gave this reaction. 37·6 per cent. of the organisms giving this reaction were typical B. coli, 61·1 per cent. of them were typical or atypical B. coli, and 97·2 per cent. of them were coliform bacilli.

4. The writer's method is described in detail. Its essentials are the rejection of shell fluid, the standardisation of the volume of each mussel at 25 c.c. by the addition of saline, the inoculation of three volumes of mussel mince into lactose bile broth—0·5, 0·1 and 0·02 cc., each in duplicate, and the regarding as positive each of these amounts only when acid and gas are produced in 24 hours in both tubes.

5. It is suggested that a batch of mussels showing more than seven positives in the tubes inoculated with 0·5 cc.. of mince, or more than three in the tubes inoculated with 0·1 c.c. or more than one in the tubes inoculated with 0·02 c.c. should be considered as contaminated to an undesirable extent.

6. Three types of solid media—Salle's, MacConkey's and Burke-Gaffney's— were tested. None were considered suitable for the bacteriological examination of mussels.

7. Reasons are given for considering any solid medium inferior to fluid medium for the bacteriological examination of mussels.

In the present study rubella HI antibodies were determined in cases of congenital malformation and bad obstetric history to determine the role of rubella in such cases in India, as it has been reported to be rare in Japan in contrast to Western countries. The incidence of antibodies was statistically significant in cases of congenital eye, c.n.s., visceral and miscellaneous malformations and cases of spontaneous abortion and still-birth compared with controls of matching age groups. This is further supported by the demonstration of IgM antibodies in seven cases of congenital malformations and ten cases of spontaneous abortion. Our findings show that congenital rubella is not rare in India.

Studies from developing countries suggest that persons with household-acquired (HA) measles are at greater risk of severe illness than persons with community acquired (CA) infection. Reported measles cases occurring among Milwaukee residents from May 1989 to June 1990 were used to assess whether household acquisition was a risk factor for severe measles in the United States. A case was classified as HA if onset of rash occurred 7–18 days after onset of rash in another case in the same household. Hospitalization rates were similar for 128 patients with HA measles (27%) and for 1004 patients with CA measles (26%). Multiple logistic regression was used to evaluate the association between hospitalization and household-acquisition after controlling for socioeconomic status, measles vaccination history, age, race, and date of onset of rash. Patients with HA measles were no more likely to be hospitalized than patients with CA measles (odds ratio 0·9, 95% confidence interval 0·6, 1·5). HA measles cases were not more severe than CA measles cases during this urban outbreak in the United States.

The carriage of Trichophyton mentagrophytes (Robin) Blanchard by symptomfree laboratory mice has been described by La Touche (1957), Dolan, Kligman, Kobylinski & Motsavage (1958) and Mackenzie (1961). It may often be only the development of infections in the animal handlers which draws attention to the carriage of the fungus by the mice. These ringworm infections in man may take the form of a rapidly developing eczematous and vesicular lesion and the mouse carrier constitutes a significant hazard to the laboratory animal worker.

Nasal swabs were taken from 492 babies born consecutively to residents of two South Wales towns soon after their discharge from maternity hospitals. Staphylococcus aureus was isolated from 352 babies (72%) and in 79 (22%) of these it was resistant to at least one antibiotic. By the time these babies were a year old the prevalence of both sensitive and resistant strains had fallen, so that only 12% still carried nasal staphylococci, but 64% of these organisms were then resistant to penicillin. Administration of penicillin to the baby seemed to be a more important factor in selecting resistant organisms than other antibiotics given to the baby, any antibiotic treatment to other members of the household, or discharge from hospital.

An examination was made of the relations between antigen, antibody and fixation of complement with foot-and-mouth disease virus (FMDV). It was found that complement fixation in this system follows the same principles as models developed in other antigen/antibody systems. The assumption that there is a relation of direct proportionality between the amount of complement fixed and the amount of antiserum reacting with constant antigen was found to be incorrect. An alternative method was proposed for the quantitative differentiation of FMDV strains by comparing the titres of an antiserum when reacting with optimum amounts of homologous or heterologous antigens.

Captive, healthy, adult badgers have blood containing haemoglobin at 13·3 g/dl, and 8·4×1012/l red cells with an MCV of 46·2 f1 and an MCH of 15·6 pg. They have 5·1×109 white cells/1 of which 3·29×109 are polymorphs, 1·49×109 are lymphocytes, 0·26×109 are monocytes, 0·07×109 are eosinophils and 0·01×109 are basophils. These values are somewhat less in adult animals just trapped from the wild, and are lower still in wild cubs.

Changes associated with tuberculosis are a rise, and then a fall in red blood count and white blood count, an increase in the proportion of polymorphs and momocytes and a fall in lymphocytes late in the disease. This picture is similar to that seen in widespread, disseminated, tuberculin negative, tuberculosis in humans, a type of disease similar to that occurring in many badgers.

BCG vaccination of badgers did not produce any measurable change in the blood picture.

The aim of this study is to assess the effects of immigration from countries with a high prevalence of tuberculosis (HPCs), of HIV/AIDS prevalence, and the ageing of the indigenous population, on tuberculosis distribution in a low-prevalence area (LPCs), the Piedmont Region of Italy. Tuberculosis incidence and HIV cases were identified by linking records from the surveillance systems. Overall, 640 tuberculosis cases were identified and crude annual incidence was found to be 17·3/100000. The incidence rate ratio for HIV infection as a risk factor for tuberculosis (11·4 and 51·9 among individuals from HPCs and LPCs respectively) was greater than that for immigration from HPCs (6·7 and 30·9 among HIV+ and HIV− individuals). Immigration accounted for a larger number of incident cases [population attributable risk % (PAR %): 31·8 and 52·8% among HIV+ and HIV− individuals] than did HIV infection (PAR %: 5·4 and 11·1% among individuals from HPCs and LPCs). Efforts should be made to identify and treat young immigrants from HPCs.

The minimum inhibitory concentration (MIC) of five antibiotics and the presence of resistance genes was determined in 163 Haemophilus influenzae isolates collected over 13 years (1987–2000) in four two-yearly sampling periods from patients with respiratory tract infections. The prevalence of β-lactamase-negative ampicillin-susceptible strains was approximately 80% over the sampling period although fewer strains (65·9%) were recovered in the period 1995–1997. TEM-1 type β-lactamase-producing strains were less frequent starting at 15·6% and declining to 2·2% in the final sampling period. Low-β-lactamase-negative ampicillin-resistant (BLNAR) strains were uncommon in 1987–1989 (2·2%), peaked to 19·5% in 1995–1997, but fell back to 11·1% by 2000. Fully BLNAR strains were not detected until the last sampling period (6·7%). The MICs of ampicillin, levofloxacin, cefditoren and ceftriaxone remained stable but there was an eight-fold increase in the MIC of cefdinir over the sampling period. Pulsed-field gel electrophoresis of DNA digests showed that three representative BLNAR strains were genetically distinct and 11 DNA profiles were identified among 17 low-BLNAR strains. These data suggest that the number of genetically altered BLNAR and low-BLNAR strains are increasing in Japan.

Woodhouse's experiments on the carcinogenicity of ten different fractions for the skin of mice have been analysed statistically. Two experiments separated by a considerable period of time were performed on each fraction.

A number of different measures of carcinogenicity were used. All agree in showing that

(1) The apparent carcinogenicity was greater in the 2nd series of experiments.

(2) There were significant differences in carcinogenicity. The fractions can be divided into three groups within which the carcinogenicities were about the same, viz. F H I K, B D G L E, M.

Multilocus enzyme electrophoresis was used to examine the relatedness of 52 isolates of Clavibacter toxicus, the agent of annual ryegrass toxicity. These included 37 Western Australian (WA) field isolates sampled in 3 distinct locations over a 2-year period, and 15 isolates sampled from 6 different host plant species in 3 states in Australia over approximately 8 years. Seventeen reference strains for the related genera Curtobacterium, Rhodococcus and Arthrobacter were examined for comparison. The 69 isolates were divided into 29 electrophoretic types (ETs), separated by genetic distances of 0·06 to 0·81. The C. toxicus isolates fell into 12 ETs, 11 of which formed a tightly clustered group separated by a genetic distance of 0·23 or less. Thirty-one of the WA field isolates of C. toxicus fell into a single ET, and four into another ET. Clavibacter toxicus therefore formed a closely related group which was genetically distinct from the other plant pathogenic species, and a dominant widely disseminated strain of the species was identified in WA.

A μ-capture enzyme-linked immunosorbent assay (ELISA) for detecting chlamydia-specific IgM was developed by use of the heat stable, lipopolysaccharide group-specific antigen and an alkaline phosphatase-labelled anti-chlamydia group-specific monoclonal antibody conjugate. The test was used to study the serological response in chlamydial respiratory tract infection among patients with acute respiratory tract symptoms in Cambridgeshire during the past 7 years. Results were compared with those of the complement fixation test (CFT) in routine use as well as those of a whole inclusion indirect immunofluorescence (WIF) test for IgM. Correlation between results of the μ-capture ELISA and those of the WIF test was 87·5%.

Six hundred and fifty-seven children aged between 0 and 12 months were randomly chosen and studied for measles antibody titres by the haemagglutination inhibition (HAI) test. The results showed significant variations in HAI antibody titres. Children between 0–3 months showed high measles HAI antibody titres which declined to a trough between 4 and 0 months. A rise in HAI antibody titre was observed from 10 to 12 months age. Multiparity and higher age in the mothers were noted as probable factors influencing the titres of measles HAI antibody in children. The results indicated that with increased maternal parity, measles HAI antibody titres in the children declined.