An indoor system designed for the study of survival of airborne micro-organisms in closed conditions has been successfully modified to allow the effect of open air to be measured. It was found that the unidentified open-air factors which are toxic for many species of microbes and rapidly lost when enclosed in conventional laboratory apparatus could be retained in the system by continuous ventilation at an adequate rate. The rate required allowed examination of Escherichia coli in aerosols generated from small amounts of material because of the short periods of ventilation required for appreciable viable decay to occur.

The validity of the system was tested by comparing the survival of E. coli in true aerosols with its survival when the droplets were held on microthread. An investigation of the role of relative humidity in open-air toxicity was included.

After instituting laboratory screening for Escherichia coli O157. H7, a Connecticut hospital isolated the organism from four persons in September 1993. As a result, an outbreak of E. coli O157.H7 associated with a country club was detected. The club had served hamburger from the same shipment at two picnics. Attendees of two picnics were interviewed, stool cultures were obtained from symptomatic persons, and the remaining hamburger was cultured. Twenty (22%) of 89 persons who ate hamburger became ill, compared with 1 of 60 who did not eat hamburger (relative risk = 13·5, 95% confidence interval 3·2–56·3). Among persons who ate hamburgers, illness was strongly associated with eating hamburger that was not thoroughly cooked (P < 0·001). All 20 samples from 5 remaining boxes of patties yielded E. coli O157.H7. Isolates from hamburger and case-patients were indistinguishable by pulsed-field gel electrophoresis. Heightened surveillance can rapidly identify outbreaks and may mitigate their impact. However, continued review of food safety issues is necessary if E. coli O157.H7 outbreaks are to be prevented.

To evaluate measles incidence and its relevant changes over a 14-year period (2000–2014), we analysed data from the regional hospital discharge database on children and adults hospitalized in Tuscany, Italy. A total of 181 paediatric and 413 adult cases were identified. Despite all the efforts towards regional measles elimination, we observed that the overall measles hospitalization rates for children and adults living in Tuscany globally increased from 0·45 to 0·85/100 000 during the study period (P = 0·001) showing fluctuations due to periodic measles outbreaks. Data stratified by age group showed that the hospitalization rate significantly increased in young adults over the study period, confirming an increase in susceptibility to measles in this subpopulation. Conversely, no statistically significant difference was observed in the hospitalization rate in the other age groups. However, children aged <1 year still exhibit the highest hospitalization rate. Pneumonia represented the most common complication in both the adult and children subsets. No death was reported. Measles still represents a public health problem, and national strategies should be implemented, focusing on emergent susceptible subsets, such as infants and young adults.

The macrophage infectivity potentiator gene (mip) from Legionella pneumophila is a major virulence factor of the species. Thus, mip-detection by amplification has been proposed to assess the presence of L. pneumophila in clinical and environmental samples. The distribution of mip-related sequences within the Legionellaceae was studied by DNA amplification using mip-specific primers followed by Southern blot hybridization with an internal probe. Thirty nine species (48 serogroups) of Legionellaceae were screened in this attempt. Using this approach, sequences related to mip were observed in 89% of the tested species including the most recently described L. fairfieldensis, L. lansingensis and L. shakespearei. In several cases, cloning and sequencing of the amplified products confirmed the high levels of similarity between the sequence found in non-pneumophila species with that of the L. pneumophila mip gene. This confirms previous reports that mip related genes are widespread among Legionellaceae and therefore specific detection of the species L. pneumophila cannot be based on mip-targeted amplification.

In May 1991 an immunization programme against Haemophilus influenzae type b (Hib) infection began within the Oxford region. We validate a deterministic mathematical model of Hib by comparison with the incidence of disease in the Oxford region, 1985–97. The comparison of model results with observed outcome allows an exploration of some of the poorly understood properties of the immunization programme. Model results and observed incidence are consistent with a vaccine that blocks the acquisition of carriage. Similarly, the data suggest that factors other than experience of Hib carriage are likely to have generated acquired immunity to Hib disease prior to the introduction of vaccination. Hence it is unlikely that waning of vaccine-derived protection will result in a resurgence of disease. The inclusion in the immunization schedule of a booster dose, as used in other countries, would have provided very little extra benefit.

The difficulties encountered in distinguishing pneumococci from streptococci, particularly S. salivarius, have been enumerated and the morphological and cultural similarities between the two groups of organisms have been pointed out. If bile-solubility is taken as the distinguishing mark of a pneumo-coccus it will be found that there are a large number of bile-insoluble streptococci commonly met with in the respiratory tract and sometimes playing an important part in disease, which bear very strong resemblances to pneumococci both in shape, colony, and broth culture. The similarities are specially confusing in mixed cultures on agar plates and a number of the routine tests applied quite failed to distinguish them. There naturally follows the corollary that some of these tests fall wide of the mark, and they should therefore be left out of the bacteriologist's armamentarium when the identification of pneumococci is under consideration. Morphological and cultural properties are insufficient guides to species, while the same is true of the widely recommended tests of inulin fermentation and capsule formation. Not only do some pneumococci fail to ferment inulin, but so many strains of S. salivarius show active inulin fermentation that, in the present series of organisms taken at random, the incidence of inulin fermenters amongst S. salivarius is actually higher than amongst pneumococci. Capsules were found in all the strains of streptococci in which they were sought and in all the pneumococci investigated, so that encapsulation may be regarded as a property common to members of both species.

The aim of this study was to explore the frequency and distribution of gene mutations that are related to isoniazid (INH) and rifampin (RIF)-resistance in the strains of the multidrug-resistant tuberculosis (MDR-TB) Mycobacterium tuberculosis (M.tb) in Beijing, China. In this retrospective study, the genotypes of 173 MDR-TB strains were analysed by spoligotyping. The katG, inhA genes and the promoter region of inhA, in which genetic mutations confer INH resistance; and the rpoB gene, in which genetic mutations confer RIF resistance, were sequenced. The percentage of resistance-associated nucleotide alterations among the strains of different genotypes was also analysed. In total, 90.8% (157/173) of the MDR strains belonged to the Beijing genotype. Population characteristics were not significantly different among the strains of different genotypes. In total, 50.3% (87/173) strains had mutations at codon S315T of katG; 16.8% (29/173) of strains had mutations in the inhA promoter region; of them, 5.5% (15/173) had point mutations at −15 base (C→T) of the inhA promoter region. In total, 86.7% (150/173) strains had mutations at rpoB gene; of them, 40% (69/173) strains had mutations at codon S531L of rpoB. The frequency of mutations was not significantly higher in Beijing genotypic MDR strains than in non-Beijing genotypes. Beijing genotypic MDR-TB strains were spreading in Beijing and present a major challenge to TB control in this region. A high prevalence of katG Ser315Thr, inhA promoter region (−15C→T) and rpoB (S531L) mutations was observed. Molecular diagnostics based on gene mutations was a useful method for rapid detection of MDR-TB in Beijing, China.

Forty-one strains of adenovirus type 19/37 (Ad19/37) mainly isolatedI from patients with keratoconjunetivitis or conjunctive between 1974 and 1984 were re-evaluated by serum neutralization (SN), haemagglutination inhibition (HI) and DNA restriction analysis. Of 19 isolates which were neutralized to high titre by antiserum prepared against prototype Ad19, 5 showed cross-reactivity with 32–64 units of Ad37 antiserum, while of 22 strains neutralizedto high titre by Ad37 antiserum, 3 showed eross-reaetivity with 32 units of Ad19 antiserum By DNA restriction analysis, all Ad19 isolates were identieal to each other and to Ad19A virus. Using endonuclease Bgl 1, three variants were observed among the Ad37 isolates.

Cervids represent a mammal group which plays an important role in the maintenance of ecological balance. Recent studies have highlighted the role of these species as reservoirs for several arthropods-borne pathogens. Globally, hemotropic mycoplasmas (haemoplasmas) are emerging or remerging bacteria that attach to red blood cells of several mammals species causing hemolytic anaemia. Therefore, the aim of this study was to investigate the occurrence and assess the phylogenetic positioning of Mycoplasma ovis in free-ranging deer from Brazil. Using a polymerase chain reaction targeting the 16S rRNA region, 18 (40%) out of 45 sampled deer were positive to M. ovis. Among the nine sequences analysed, four distinct genotypes were identified. The sequences detected in the present study were closely related to sequences previously identified in deer from Brazil and the USA. On the other hand, the Neighbour-Net network analysis showed that the human-associated M. ovis genotypes were related to genotypes detected in sheep and goats. The present study shows, for the first time, the occurrence of M. ovis in Mazama gouazoubira and Mazama bororo deer species, expanding the knowledge on the hosts harbouring this haemoplasma species. Once several deer species have your population in decline, additional studies are needed to evaluate the pathogenicity of M. ovis among deer populations around the world and assess its potential as reservoir hosts to human infections.

A total of 292 children's sera and 706 antenatal sera from different parts of England were tested for the presence of poliovirus neutralizing antibodies. Little variation was found between different areas and types of community, but a lower proportion of the 5–14 year old children had antibody than younger children and young adult women. The proportion of the young population with antibody, and the current acceptance rates for oral poliovirus vaccine are barely satisfactory.

Coumatetralyl was evaluated in the laboratory against Bandicota bengalensis and Rattus rattus. Feeding tests with 0·0375 % coumatetralyl baits produced 100 % mortality after a single day feeding period in B. bengalensis and after a 10–day period in R. rattus. The anticoagulant bait is less palatable in comparison to plain bait. In the case of R. rattus, LFP50 and LFP98 and their 95 % confidence limits were 3·89 (2·62–5·77) days and 11·22 (6·1–20·65) days respectively. Median period of survival and its 95% confidence limits of B. bengalensis and R. rattus were 4·7 (3·85–5·7) days and 11·2 (9·33–13·44) days respectively.

In January, 1923, a small outbreak of dysentery occurred amongst the nursing staff of a certain institution. In all there were six cases. Only one case, the first which occurred, showed symptoms of any great severity. In the remaining five cases the symptoms were slight, and the patients were able to return to duty m seven or eight days from the commencement of the illness.

In recent years, mycoplasma taxonomists have found that numerous mycoplasma strains from goats are serologically indistinguishable from Mycoplasma mycoides subsp. mycoides, the causative agent of contagious bovine pleuropneumonia (CBPP), by routinely used tests, e.g. the metabolism-and growth-inhibition tests. As a result, such organisms are now openly referred to as M. mycoides subsp. mycoides.

Seven of these so-called M. mycoides subsp. mycoides strains from goats were compared with two strains of M. mycoides subsp. mycoides from CBPP, and with one strain of M. mycoides subsp. capri, by means of two in-vivo tests, namely, (1) a test of the ability of each strain, injected intraperitoneally into mice, to produce mycoplasmaemia, and (2) a cross-protection test in mice. Of the seven strains, only one (‘O goat’) was indistinguishable from genuine M. mycoides subsp. mycoides; it also had small colonies resembling those of genuine M. mycoides subsp. mycoides. The other six were easily distinguished from genuine M. mycoides subsp. mycoides, and they produced large colonies. These six strains and others like them should no longer be given a name that fails to distinguish them from the causative agent of CBPP.

Cross-protection tests showed that the seven goat strains referred to above differed from M. mycoides subsp. capri.

This matched case-control study investigated the risk factors for sporadic Salmonella Infantis infection in 263 affected children and 263 age-, gender- and neighbourhood-matched controls. Information about exposure to potential risk factors was obtained via telephone interview and evaluated by conditional logistic regression analysis. Age groups ⩽1 year (n = 77) and >1 year (n = 186) were analysed separately. Of those aged ⩽1 year, breastfeeding was a significant protective factor against infection [matched odds ratio (mOR) 0·24, 95% confidence interval (CI) 0·10–0·59, P < 0·01]. In the older group, consumption of eggs (mOR 1·87, 95% CI 1·00–3·49, P = 0·05) was a significant risk factor and thawing chicken in water (mOR 2·55, 95% CI 0·94–6·91, P = 0·07) was borderline risk factor, while consumption of carrots (mOR 0·46, 95% CI 0·26–0·83, P < 0·01), drinking tap water (mOR 0·44, 95% CI 0·22–0·85, P = 0·02), religious lifestyle (mOR 0·40, 95% CI 0·21–0·74, P < 0·01) and having a high number of children in the household (mOR 0·72, 95% CI 0·58–0·88, P < 0·01) were significant protective factors. Consumers should avoid eating undercooked eggs and food handlers should be educated regarding proper handling and cooking of eggs. Breastfeeding should be strongly encouraged by public health authorities. The public must be educated on stringent hygiene practices, especially proper cooking of eggs to reduce infection rates.

This study investigated whether exposure to inactivated rabbit haemorrhagic disease virus (RHDV) can produce an antigenic response in rabbits and protect them from a subsequent challenge with virulent virus. The aim was to determine if the spreading of baits containing RHDV, which is a common management practice in New Zealand to reduce rabbit numbers, could result in protective immunity in wild rabbits. RHDV was inactivated by ultraviolet (UV) light using an electronic UV crosslinker with a UV dose of 168·48 W-s/cm2 and a UV intensity of 0·0078 W/cm2. Two groups of four rabbits were then inoculated with inactivated virus via oral and intramuscular routes. Rabbits were monitored for 30 days post-inoculation and then challenged orally with virulent virus. No rabbit exposed to inactivated RHDV developed clinical signs of RHD or had antibodies at day 30 post-infection and all animals died within 82 h after challenge with virulent virus. No antibodies were detected at the time of death. These findings suggest that exposure to virus completely inactivated by UV light in the field or on baits will not protect rabbits against challenge with virulent virus.

In most European countries the geographical distribution of simple goiter is known from the number of men who are rejected on this account for military service(1,2). There are no similar figures for Britain but what is known about its probable incidence has been discussed by Hirsch(2) and by Berry(3) and in a more recent paper, where it was also shown that there was a geographical distribution of the deaths from “exophthalmic goiter” as recorded in the Registrar General's reports(5). There were still many gaps in our knowledge, especially as regards simple goiter, but there appeared to be some tendency for deaths from “exophthalmic goiter” to be more frequent in areas where goiter was endemic, thought this was contrary to the evidence of most parts of the world where goiter was seriously endemic.

Small colony (SC) strains of Mycoplasma mycoides subsp. mycoides from contagious bovine pleuropneumonia (CBPP) and from goats were compared with large colony (LC) strains of so-called M. mycoides subsp. mycoides from goats and sheep by means of a cross-protection test in which mice were challenged with M. mycoides subsp. capri.

Of 13 LC strains, all gave partial cross-protection, and 11 were shown to be more closely related than four SC strains to subspecies capri. In a further experiment, six SC strains – three from CBPP and three from goats – all gave weak partial cross-protection against subspecies capri.

Staphylococcus aureus is a leading cause of infections in deployed service members. Based on a molecular epidemiological study of 182 MRSA isolates from patients in three U.S. Army combat support hospitals in separate regions in Iraq, USA300 clone was the most predominant (80%) pulsotype. This finding suggested that strain carriage from the home country by military personnel is epidemiologically more important than local acquisition.

1. An epidemic of typhoid fever involving 135 persons in a semi-closed community of. 742 persons is described.

2. There were nineteen symptomless excreters (14·1%).

3. Among the 116 clinical cases there were seven deaths, giving a case fatality of 6.03%. If the case fatality were calculated on the total persons involved (including symptomless excreters), the figure would be 5·2%.

4. The origin of the outbreak was not discovered, but there was strong cricumstantial evidence in favour of a milk-borne infection.

1. Of 585 strains of lactose-fermenting aerobes each isolated from faeces of a different person, 501 did not utilise citrate or ferment cellobiose; 20 were citrate negative and cellobiose positive; 27 were cellobiose negative and citrate positive; and 37 were positive to both tests.

2. Almost 10 per cent, of the strains isolated were indol negative.

3. One culture was methyl-red negative and Voges-Proskauer positive. Two were positive to both tests. The rest were methyl-red positive and Voges-Proskauer negative.

4. It is concluded that the results are not favourable to the use of the citrate or the cellobiose test in routine water analysis.

5. A discussion of the taxonomy of the lactose-fermenting aerobes is given. Only two species, Bacterium coli (Escherich) L. and N., and Bacterium aerogenes (Escherich) Chester, are recognised.