bluuebunny/crossref_metadata_2025 huggingface dataset:
The intracerebral infection of mice with Bordetella pertussis
Authors: Dolby Jean M. , Standfast A. F. B.
Published: May 2009

The growth of virulent strains of Bordetella pertussis in the brains of mice was studied by carrying out viable counts on mice killed at various times during the infection. The results suggested that this system conformed to the general model which postulates that the organisms causing death multiply in vivo at a rate which is constant for all doses and that death is certain to occur when the number of organisms reaches a certain constant figure.

Perhaps the most important factor in this route of infection is the lodgement of the parasite in the host, for if this is accomplished a single organism grows until the lethal level is reached. There is no sublethal infection.

In actively and passively protected mice, the growth of the organism is approximately the same as in unprotected controls for the first 4–5 days. At this time there is a striking change in protected animals and the viable count falls rapidly and progressively and the animals survive. At the same time the blood-brain barrier becomes permeable and circulating antibodies diffuse into the brain. In vitro, specific antisera plus complement are highly bactericidal.
Infestations of the brown rat (Rattus norvegicus) in drift mines of the British Isles
Authors: Twigg G. I.
Published: May 2009

Questionnaire survey of the drift mines of the British Isles revealed that the presence or absence of rat infestations could be related to the size of the mine in terms of manpower, large mines being more commonly infested than small ones. In addition, various features of drift mines and their surroundings, i.e. the presence of urban areas, nearby rat concentration points, canteen and surface stables, horses, the absence of buildings and the type of surface sanitation are all related to infestation. Field survey has shown that the extent of dilapidation and piling of waste material assists infestation. It has also indicated that the greater infestation of pits with large numbers of workmen is due to some extent to the extra cover provided by the greater number of surface buildings, these being few or lacking altogether in small pits.

At a mine at which changes in the rat population were studied it was seen that unsuccessful poisoning could leave a breeding nucleus of rats, but that there could also be a speedy re-invasion even after successful poison treatments. Whilst the surface rat population in the buildings of this mine was controlled there were no underground infestations. It appears, therefore, that regular inspection and control of surface infestations should in most cases prevent underground infestation.

This work was carried out under a research grant from Safety in Mines Research Establishment, Ministry of Power, and I am indebted to the Ministry for permission to publish the results. I should like to express my gratitude to the several members of the staff of the Safety in Mines Research Establishment, Sheffield, for the help they gave, in particular Mr C. S. W. Grice. I should like also to thank Prof. L. E. S. Eastham in whose department the work was carried out, Dr E. T. B. Francis who supervised it, Miss B. B. Jones of the Ministry of Agriculture, Fisheries and Food, and the many employees of the National Coal Board who assisted at various times.
The effect of chlorination on chicken carcasses infected with Salmonellae
Authors: Dixon J. M. S. , Pooley F. E.
Published: May 2009

A study was made of the effect of chlorine solutions on broiler chicken carcasses that had been artificially infected with salmonellae. One hundred and sixteen carcasses were infected with widely varying numbers of seven different salmonella serotypes.

Treatment of carcasses with 200 p.p.m. of chlorine for 10 min. usually prevented the subsequent recovery of salmonellae when fewer than 1000 organisms had been inoculated. When larger numbers of organisms were inoculated or when lower concentrations of chlorine were used, salmonellae were usually recovered from the treated carcasses.

It is suggested that the incorporation of chlorination with 200 p.p.m. for 10 min. into the routine processing of poultry carcasses would greatly reduce the number of contaminated birds leaving processing factories.

We wish to thank the management of a local poultry-packing factory for their co-operation, without which this investigation would not have been possible. We are also grateful to Miss P. E. Ellis for technical assistance.
The influence of technique on the sensitivity of monkeys to intraspinally inoculated poliovirus
Authors: Beswick T. S. L. , Coid C. R.
Published: May 2009

1. Two methods of injecting monkeys intraspinally are compared.

2. It has been shown that the technique of inserting the needle through the cord and withdrawing it 1–2 mm. before injection (Sabin's technique) gives a less widespread distribution of inoculum than the alternative method of making the injection as soon as the tip of the needle is within the substance of the spinal cord (‘standard technique’).

3. When attenuated Type 3 poliovirus is injected into cynomolgus monkeys by Sabin's technique, the incidence of paralysis and poliomyelitis lesions observed is less than when it is injected by the ‘standard technique’.

4. The relative merits of the two techniques are discussed.
Association of PPLO infection and antibody response in rats and mice
Authors: Lemcke Ruth M.
Published: May 2009

By means of a complement-fixation test of the sera of laboratory rats and mice, the immunological response of these animals to both naturally occurring and induced PPLO infections was determined, and the presence and extent of infection in the animals determined by culture.

PPLO antibodies specific for the infecting strain were demonstrable in rats and mice from which PPLO were isolated.

The amount of serum antibody rises with the extent and severity of the infection. Thus, young rats with PPLO infections confined to the nasopharynx had little or no antibody whereas the oldest rats with consolidated lungs had the highest titres. In mice too, the sera of those with pneumonia had the highest titres.

The comparatively low titres found in rat bronchiectasis together with the failure to isolate PPLO from the spleen and other organs, suggest that the chronic form of the disease remains localized. This is in contrast to infections with rat polyarthritis and related PPLO in which the organisms can be isolated from the lymph nodes and other organs and in which antibody is present in high titre.

In view of the high degree of correlation between the presence of antibodies to PPLO in the blood and the presence of PPLO in the tissue of rats and mice, it is suggested that specific antibody found in man is a significant indicator of PPLO infection.
Staphylococcal infections following childbirth
Authors: Hughes M. H.
Published: May 2009

An investigation is reported into sepsis due toStaphylococcus aureusin the maternity unit of a provincial hospital and in domiciliary midwifery in the same town.

In the hospitalStaph. aureusinfections of mother or infant occurred 123 times per 1000 live births in one ward and 116 per 1000 in another, but the use of hexachlorophane powder on the infants in one ward reduced the sepsis rate in that ward to 34 cases per 1000 live births, thus confirming the reports by two teams in Bristol hospitals. Sepsis was more frequent in both mothers and infants after Caesarean delivery than after normal labour. Reasons are given for thinking that ‘sticky eyes’ are usually not caused by the bacteria isolated when the eyes are swabbed.

The rate of infection in domiciliary cases was 39 per 1000 live births. As all these were normal deliveries the sepsis rate cannot be directly compared with that occurring among complicated cases in hospital.

No evidence was found that hospitalStaph. aureusstrains carried home by newly born infants were causing a significant amount of sepsis among their home contacts within 28 days of delivery.

The importance of nurses as sources of infecting strains ofStaph. aureusin maternity work is discussed. The infant-to-infant route of transmission has been stressed in the literature but reasons are given for believing that nurse-to-infant infection in the labour room may also be important under certain circumstances.

I am greatly indebted to Dr V. P. Randall Martin, formerly Senior Medical Officer in the Hampshire County Health Department, who organized the follow-up of patients after leaving hospital and after home delivery, and also to the County Medical Officer Dr I. A. MacDougall for his help.

I am also grateful to Messrs P. R. Mitchell and G. T. Hammond for permission to investigate their wards and to Sister D. M. Carter and her staff, and to the County midwives and Health Visitors, for their co-operation.

Dr G. J. G. King kindly undertook the phage-typing of a large number of strains ofStaph. aureusat the Bournemouth Public Health Laboratory, for which I am most grateful.

I am also grateful to Dr W. A. Gillespie for information in advance of publication, and for advice, about the hexachlorophane regimen of which he and his Bristol colleagues were the pioneers.
Allergy in experimental rat tuberculosis
Authors: Gray David F. , Noble John L. , O'Hara Mary
Published: May 2009

1. This paper confirms and extends several observations during the past 20 years that, despite many reports to the contrary, the rat is not unduly resistant to initial infection with tubercle bacilli provided they lodge in the lungs.

2. The pattern of pathogenesis in the rat is probably closest to the now classical picture in the mouse, i.e. the response of a species with a low hypersensitivity potential. The pathology of the lesions agreed closely with the descriptions of Wessels (1941) and Kumashiro (1958b) resembling the mouse in most respects but, unlike the mouse, including the production of giant cells.

3. When tested by footpad inoculation with 1/3·5 Old Tuberculin a positive reaction was demonstrated, commencing between 2 and 5 weeks after infection and persisting for several weeks. A fatal systemic reaction could often be induced with large doses of tuberculin given intraperitoneally.

4. In a few cases loss of allergy was shown to be associated with a terminal anergic flare of the type observed previously in mice and guinea-pigs.
The relative natural resistance of rats and mice to experimental pulmonary tuberculosis
Authors: Gray David F.
Published: May 2009

1. Wistar-albino rats showed no significant difference from albino mice in their response to pulmonary tuberculosis. This conclusion was reached after a detailed comparison of bacillary multiplication, lung involvement, death rates and the rate of conversion to the immune state as determined by footpad reaction to tuberculin in the two species.

2. These findings support the theory that the key to species differences in resistance to tuberculosis is the rate of onset of acquired immunity and it is therefore unrelated to natural resistance.
Complement-fixation and complement-fixation-inhibition titres against the Bedsonia antigen in sera of trachoma patients
Authors: Terzin A. L. , Birtašević B. V.
Published: May 2009

Sera of 132 selected patients belonging to stages II, III or IV of clinical trachoma have been tested by CF-test against the ether-soluble, group-specific Bedsonia antigen, as well as by CF-inhibition test against an indicator system of the same group-reactive specificity.

On the basis of the serological results obtained, the following conclusions have been advanced:

Trachoma patients do not develop group-specific CF-inhibiting antibodies in their sera.

The group-reactive (anti-Bedsonia) CF-titres found in sera of trachoma patients represent residual titres developed in response to past infections with agents other than trachoma. There is no satisfactory explanation for the fact that in trachoma patients neither CF, nor CF-inhibiting antibodies develop against the group-reactive Bedsonia antigen, which is known to be produced also by the virus of trachoma.

Statistical analyses revealed that, in the group of stage IV trachomas, the mean values of the anti-Bedsonia CF-titres were significantly higher than those found in the groups of stage II or III, as well as that the factors responsible for that difference must be other than the duration of the trachoma.

A hypothesis was advanced to explain the appearance of the highest group specific mean-titre revealed by the group of stage IV cases.
Atmospheric ions and comfort
Authors: Koch Walter
Published: May 2009

1. Fifteen apparently healthy persons were exposed to air enriched with positive or negative ions at 78° F. and 87° F. Average ion counts at 78° F. were 12,324 positive ions per ml. and 5,451 negative ions per ml. The averages at 87° F. were 14,865 positive ions per ml. and 5,442 negative ions per ml. Relative humidity was kept at 50% and air motion was 28 ft./min.

2. Seven sensations related to comfort (thermal sensation, humidity sensation, sensible perspiration, air motion, pleasantness, mood and fatigue) were recorded, pulse rate and oral temperature were measured.

3. In the experiments at 78° F. mood was improved (P < 0·001) by positive ionization. All other qualities remained unaffected by positive ionization. No effect was found under negative ionization at the ion concentration applied.

4. In the experiments at 87° F. five sensations (thermal sensation, sensible perspiration, pleasantness, mood and fatigue) were significantly (P < 0·001) improved by ionized air. In general, as can be seen from the significantly differences between grand means, the subjects felt cooler, perspired less, felt more pleasant, were in a better mood, and felt less fatigued under the influence of air enriched with ions.

Air motion sensation, humidity sensation, pulse rate and oral temperature were not affected by ionization.

5. As different individuals may vary in their response to ionization, individual preferences were tested. These tests indicated that at 87° F. six out of the fifteen persons tested preferred ionized air (P < 0·001). One person preferred air not enriched with ions (P = 0·0091).
A method for measuring the retained dose in experiments on airborne infection
Authors: Harper G. J. , Morton J. D.
Published: May 2009

When killed radioactive bacterial spores are inhaled by guinea-pigs and retained in the lung, it is found that the rate of loss up to 5 weeks later is sufficiently constant for the initial retention of a group of animals to be calculated from the measured retention at a later time (say 3 weeks after exposure). If, therefore, the inhaled cloud contained also a pathogen, in known proportion to the spores, the initial retention of the pathogen could be calculated. The experiments apply to groups of animals, but it is believed that the conclusions are valid also for single animals. In experiments withBr. suisit was found that the fate, as regards infection, of individual animals within a group exposed to a common dosage was not significantly related to the estimated retained dose, despite the wide variation of individual doses about the group mean.
The effect of desiccation on the viability of Staphylococcus aureus
Authors: Rountree Phyllis M.
Published: May 2009

The death-rates have been determined of strains of Staphylococcus arueus dried on lint and other textiles and stored at room temperature in the dark.

Two categories of strains were distinguished, those that showed no significant loss of viability after 15 days storage and those whose death commenced from the beginning of the drying period.

There was some degree of correlation between survival for 15 days and implication in epidemics of hospital infection.
A seventeen-year survey of the ringworm flora of Birmingham
Authors: Carlier Gwendoline I. M.
Published: May 2009

The nature of the ringworm flora of Birmingham over 17 years was investigated and tabulated by species, geographical distribution and concentration.

The rise and fall of such outbreaks as occurred has been charted.

The persistent preponderance of zoophilic species, in spite of the recent decline in over-all incidence, has been demonstrated.
Autoradiographic detection of radioactive bacteria introduced into sea water and sewage
Authors: Berlin Maths , Rylander Ragnar
Published: May 2009

An autoradiographic method to trace the dissemination in water of radioactive bacteria is reported. It has been tested for accuracy and sensitivity and a field trial has been performed. The method appears suitable for practical use and permits the study of environmental effects on the spreading bacteria.
Infectivity of influenza virus aerosols
Authors: Hood A. M.
Published: May 2009

The PR8 strain of influenza virus can remain viable in ageing aerosols for considerable periods (Harper, 1961). However, viability of micro-organisms determined by their growthin vitromay not indicate their ability to infect animals via the respiratory route (Schlamm, 1960; Hood, 1961). If influenza is normally transmitted via this route it is epidemiologically important to establish whether any correlation exists between viability as measured byin vitroorin ovomethods and respiratory infectivity for a susceptible animal host. Previous reports on respiratory infectivity of aged influenza virus aerosols by Edward, Elford & Laidlaw (1943), Loosli, Lemon, Robertson & Appel (1943a) and Loosli, Robertson & Puck (1943b) lack such a comparison.
In vitromeasurement of the potency of inactivated foot-and-mouth disease virus vaccines
Authors: Brown F. , Newman J. F. E.
Published: May 2009

Inactivated vaccines have been prepared from one strain of FMD virus grown in guinea-pig pad epithelium, unweaned mice and cultured pig kidney and baby hamster kidney cells. The potencies of these vaccines in protecting guinea-pigs against challenge with inoculated infective virus of the same strain have been compared and related to the amounts of 25 mμ component present in the different virus suspensions. Although it was possible to obtain a relationship between the content of 25 mμ component and potency for an individual source of virus, this relationship does not hold for all the different sources of virus used. It is suggested that the reason for this failure is the partial masking of the 25 mμ component by a cell constituent present in some of the virus suspensions so that the component is incompletely estimated by the complement-fixation test.
The epidemiology of louping ill in Ayrshire: the first year of studies in sheep
Authors: Smith C. E. Gordon , McMahon Dolores A , O'Reilly K. J , Wilson A. L , Robertson J. M
Published: May 2009

1. Following an epizootic of louping ill on certain farms in south-west Ayrshire in 1960, a long-term study of several farms was initiated.

2. The flocks on two hirsels of one farm were studied during spring and early summer of 1961. Although only one lamb death was confirmed as due to louping ill, the infection rates in sentinel hoggs on the two hirsels were 50–60. and 11% respectively. The difference between the hirsels is probably attributable to the difference in the amount of tick habitat on them.

3. The ewes were bled in March and June and their lambs in June. Haemagglutinin inhibition (HI) and neutralization tests revealed that the HI antibody is much shorter lasting than neutralizing antibody. Many ewes, therefore, had neutralizing but not HI antibody. Otherwise agreement between the tests was good. In March almost all the ewes aged 3 years or more had antibody. Of the gimmers (2-year-olds) about two-thirds on one hirsel and one-third on the other had antibody in March: by June almost all the former and about half of the latter had antibody.

4. About two-thirds of the lambs had the same antibody status as their mothers in June and almost all the rest had less antibody than their mothers. Serological evidence suggestive of louping ill without recognizable clinical disease was found in six lambs and a further lamb recovered from clinical disease.

5. Revaccination of two-thirds of the flock failed to cause any detectable change in antibody status.

6. The epidemiology and pathogenesis are discussed in relation to immunity and infection rates, and to the design of control measures.

We are greatly indebted to the late Mr James Murdoch at Dalmellington, Mr John Murdoch at Dalcairnie Farm, and Mr David Murdoch at Knockgray Farm for permission to work on their farms and for all the help they gave us during the study.
Serological studies on group- and species-specific antigens of trachoma and inclusion conjunctivitis (TRIC) agents
Authors: Terzin A. L. , Vedros N. A. , Johnston J. B.
Published: May 2009

Group-reactive ether soluble psittacosis and boiled mouse pneumonitis antigens were tested in parallel, with 85 serum specimens. The results indicate that the group-specific C.F. antigens of these organisms are indistinguishable when tested against sera of trachoma patients, monkeys infected with trachoma or against sera of other individuals.

Sera of rabbits immunized with viable trachoma-inclusion conjunctivitis (TRIC) organisms, grown in tissue culture, were absorbed with boiled elementary body suspension of mouse pneumonitis agent, which removed the group reactive antibodies, and resulted in a species-specific anti-TRIC serum.

The absorbed and unabsorbed TRIC sera were titrated against purified E.B. suspensions, which were prepared both from yolk and from tissue culture grown organisms, of homologous TRIC strains and from other heterologous Bedsonia organisms.

Results of absorption experiments indicate that group reactive antigens prepared from mouse pneumonitis and psittacosis are indistinguishable by C.F. test from the group-specific component of the TRIC antigens. The species-specific antigen of the TRIC agents was well distinguished from the species-specific antigen of the psittacosis agent. However, the C.F. test did not distinguish the strains isolated from trachoma from those isolated from cases of inclusion conjunctivitis.

The stabilizing effect of sucrose and albumin upon the species-specific C.F. antigen of purified elementary bodies of TRIC organisms was found to be pronounced.

Our attempts to produce a species-specific antigen preparation, free from group component, failed.

We have pleasure in thanking Dr F. B. Gordon for suggestions; Dr B. V. Birtašević, Mr H. R. Dressler, Dr E. S. Murray and Dr A. J. Vargosko for procuring sera of patients or organisms grown in tissue culture; Dr T. A. Strike for the help with statistical computations; HMC P. R. Hill, HM3 C.O. Wiese and Mr B. L. Ward for invaluable technical assistance.
Cell-free varicella-zoster virus in tissue culture
Authors: Caunt Anne E. , Taylor-Robinson D.
Published: May 2009

Infected human thyroid tissue cultures have been found to yield free V-Z virus on ultrasonic disintegration and some virus is also present in the fluid phase of intact tissue cultures, while the yield of virus from infected human amnion cells is very low and no free virus is found in the fluid phase. Thyroid cultures are more susceptible to infection with V-Z virus, and the infected cultures are a better source of complement-fixing antigen, than are amnion cultures.

The lack of free virus in infected amnion tissue cultures cannot be attributed to protection by interferon. It also seems likely that if any infectious virus were released it would be more likely to be adsorbed to normal cells than to be inactivated, but as no secondary foci appear in amnion monolayers we conclude that infective virus is not released into the medium.

It is suggested that the virus in thyroid cells is present in a more complete form than that in amnion cells.

We are grateful to Dr R. M. Rawcliffe of Birkenhead General Hospital and Dr F. Whitwell of Broadgreen Hospital, Liverpool, for arranging the supply of thyroid tissue.
The epidemiology of leptospirosis in North Queensland: I. General survey of animal hosts
Authors: Emanuel Marie L. , Mackerras I. M. , Smith D. J. W.
Published: May 2009

Leptospirosis is a zoonosis that causes appreciable ill health and economic loss in North Queensland. Fourteen serotypes ofLeptospirawere known to infect man in the area, and information on their local distribution and seasonal and occupational incidence had been obtained. The next step in the investigation was to determine the reservoir hosts and estimate their significance.

Wild animals examined comprised 5 monotremes, 643 marsupials, 2355 rodents, 67 bats, 30 birds, 28 reptiles, and 21 toads. Evidence of leptospiral infection was obtained from 223 marsupials, 309 rodents, and 6 fruit-bats. Analysis indicated that the principal maintaining hosts were:Peremeles nasuta—ofL. kremastos(and possiblyL. mini) in canefields and rain forest.

Isoodon macrourus—ofL. broomi, L. mini, andL. kremastosin canefields.

Rattus rattus, R. norvegicus(focal), andMus musculus(focal)—ofL. zanoniin town and canefields.

Rattus sordidus conatus—ofL. australisin canefields.

Rattus assimilis—of foci ofL. australis, a variant ofL. pomona, and probably ofL. hyosin rain forests.

Random infections were also encountered, but the maintaining hosts of the other serotypes known to infect man in the area (icterohaemorrhagiae, canicola, bindjei, robinsoni, bratislava, grippotyphosa, medanensis, celledoni) were not determined.

Domestic animals examined included 137 cattle, 54 pigs, 7 sheep, 34 dogs, 31 cats, and a dairy herd in which there was an epizootic ofpomonaleptospirosis. Again, there was a wide scatter of infection, but, apart from the long-known association ofL. pomonaandL. hyoswith cattle and pigs, there was no evidence of maintaining hosts in this series.

As indicated in the Introduction, the work reported here was part of a planned investigation into the epidemiology of leptospirosis. Some of the early material was collected by Dr M. J. Mackerras, Dr R. L. Doherty, Mrs D. G. Delamoir, and Miss C. J. Ross, who had previously been stationed at the Institute's Field Station, and we are indebted to Mr D. W. Lavers, Mr S. G. Knott, and Mr R. E. Dunham, of the Queensland Department of Agriculture and Stock, for a number of sera from domestic animals. Many of the mammals were identified by Dr W. A. McDougall, of the Queensland Department of Agriculture and Stock, Mr E. le G. Troughton, then of the Australian Museum, Sydney, Mr B. J. Marlow, then of the C.S.I.R.O. Wildlife Section, Canberra, and by Dr J. L. Harrison, Dr M. J. Mackerras, and Mr R. Domrow of the Institute. We are indebted also to Mrs M. Macgregor, Librarian of the Institute, for considerable help with the literature.
Source ofPseudomonas aeruginosainfection in premature infants
Authors: Rubbo Sydney D. , Gardner Joan F. , Franklin J. Clare
Published: May 2009

1. A small but serious outbreak ofPs. aeruginosainfection in a premature baby ward has been described.

2. Heavy contamination of the suction apparatus and tubing was demonstrated to be the main reservoir of infection.

3. It was also shown that this apparatus could disseminate the organism as an aerosol.

4. The measures adopted to eliminate the source and prevent dissemination of the infectious agent have been described.
Salmonellae and shigellae in a group of urban South African Bantu school children
Authors: Richardson N. J. , Koornhof H. J. , Hayden-Smith S.
Published: May 2009

1. Faeces from apparently healthy Bantu children from schools in Soweto township near Johannesburg were examined eight times at fairly regular intervals over a period of 1 year.

2. Only fifty-five children were present for all eight investigations and, of these, 36·4% yielded salmonellae and 9·1% shigellae. Taking the group as a whole, 26·2% of the children had salmonella infections and 6·2% shigella infections.

3. Parasites were shown to be present in sixty-four of the 130 children during the period of the investigation.

4. As in other surveys, there were more isolations in summer than in winter.

5.S. labadiandS. typhimuriumwere most frequently isolated, with the group B–E constituting 75% of the total isolations.S. typhi, S. paratyphi A, BandCwere not found.

6. Water supplied to each house by the Johannesburg municipality was of good quality, yet it did not affect the incidence of salmonellosis and shigellosis.

7. In spite of better socio-economic conditions the incidence of salmonellosis is comparable to the two previously mentioned surveys. These findings indicate a lack of instruction on personal hygiene and the importance of public health measures.
The nucleic acid of African horse sickness virus
Authors: Mirchamsy H. , Taslimi H.
Published: May 2009

The effect of actinomycin D on the growth of African horse sickness virus in monkey kidney cells was studied. It was found that actinomycin D inhibited the yield of virus. It is suggested that African horse sickness virus is either a DNA containing virus or an RNA virus whose replication is DNA-dependent.
Salmonellas of subgenus III (Arizona) isolated from abattoirs in England and Wales
Authors: Harvey R. W. S. , Price T. H. , Dixon J. M. S.
Published: May 2009

Using Moore's swabs in four abattoirs, six strains of subgenus III salmonellas were isolated—four diphasic strains belonging to one serotype and two monophasic strains belonging to another. The serotypes differed in the length of time needed to ferment lactose. There was some evidence that the diphasic serotype could have had an ovine origin.
Some laboratory observations on the toxicity and acceptability of norbormide to wildRattus norvegicusand on feeding behaviour associated with sublethal dosing
Authors: Greaves J. H.
Published: May 2009

The median lethal dose of orally administered norbormide for wildRattus norvegicusfound to be 9·0 mg./kg. of body weight and the LD 95 about 17·0 mg./kg.

In tests in which various concentrations of norbormide or zine phosphide were added to the food of individually caged wild rats, mortality increased with concentration of poison, though more slowly with norbormide than with zine phosphide. The mortality that occurred among rats offered a choice between unpoisoned food and the same food with added norbormide or zinc phosphide indicates that in control treatments in the field the optimum concentration of norbormide in bait would be about 0·;5% and that this might be expected to give results comparable with those obtainable with 2·;5% or 5·0% zine phosphide. Other methods of estimating suitable field strengths indicate that concentrations of norbormide higher than 0·;5% may be preferable.

Some animals that survived exposure to a choice of plain food and the same Food poisoned with norbormide or zine phosphide at field concentrations avoided mating lethal amounts by reacting to the taste of the poison. Others learned to use the taste of the food, not that of the poison as a cue and later avoided eating the food when it contained no poison.

When either poison was presented to rats in the more palatable of two foods in the choice situation mortality was relatively high. Some of the surviving animals subsequently rejected the more palatable food in preference to the normally less palatable alternative.
Some studies on the epidemiology of sonne dysentery. Changes in colicine type and antibiotic resistance between 1956 and 1965
Authors: Farrant W. N. , Tomlinson A. J. H.
Published: May 2009

The colicine type and antibiotic resistance have been determined on strains ofSh. sonneiderived from 9419 incidents of Sonne dysentery in London between October 1956 and March 1965.

The most striking observation has been the appearance of strains with patterns of colicine production and antibiotic resistance new to the area. These changes are best regarded as a result of the interaction and transfer of characters betweenSh. sonneiand other intestinal organisms.

The general tendency has been for strains ofSh. sonneito become increasingly resistant to antibiotics but this has not been an uninterrupted process. The proportion of drug-resistant strains at any one time depended on the properties of the current epidemic strain.

Spread of Sonne dysentery was essentially local, but some strains ofSh. sonneiwere found to spread much more widely than others. Most, but not all, of the strains resistant to streptomycin and tetracycline possessed only limited powers of spreading.
The isolation and classification of Tern virus: Influenza Virus A/Tern/South Africa/1961
Authors: Becker W. B.
Published: May 2009

The aetiological agent of an epizootic among Common Terns (Sterna hirundo) in South Africa in 1961 was isolated from several sick birds and named Tern virus. It was classified on the basis of antigenic and morphological properties as a strain of avian influenza virus, Myxovirus influenzae A/Tern/South Africa/1961. The strain-specific antigen of Tern virus was unrelated to all known influenza strains with the single exception of Chicken/Scotland/1959 virus and the two viruses may be regarded as variants of the same strain. This relationship raised the interesting epidemiological possibility of the spread of infection between sea-birds and domestic poultry because the Common Tern migrates between Europe and South Africa.
The mathematical analysis of concurrent epidemics of yaws and chickenpox
Authors: Gart John J. , De Vries J. L.
Published: May 2009

The relationship between chickenpox and yaws epidemics occurring among children in a village in Netherlands New Guinea is analysed using the mathematical model for a simple deterministic epidemic. It is shown that the yaws epidemic accelerated significantly in the month following the chickenpox epidemic, but that it reverted to its previous rate in the succeeding months. The number of yaws cases attributable to the influence of the chickenpox is estimated from the projected course of the yaws epidemic. It is statistically verified that those children contracting chickenpox were more likely to become yaws cases in the subsequent month.

These results point to the danger of yaws's spread being much more rapid among a population which has recently been subject to an epidemic of chickenpox.
The distribution of complement-fixing antibody and growth-inhibiting antibody to Mycoplasma hominis
Authors: Jones D. M. , Sequeira P. J. L.
Published: May 2009

Sera from 3163 patients were examined for growth-inhibiting and complement-fixing antibody to Mycoplasma hominis. The results were analysed in respect of the age and sex of the patients. Antibodies were found to be uncommon in young people but increased in frequency with age; they were present in old men but were less common in women over sixty-five. Patients attending V.D. clinics and prison inmates had a much higher incidence of antibody than hospital and ante-natal patients. Complement-fixing antibody was approximately three times as common as growth-inhibiting antibody in the sample examined; it was also more common in women than men but the overall incidence of growth-inhibiting antibody was the same in each sex. It was concluded that possibly growth-inhibiting antibody is produced in more severe infections and that it disappears from the serum more quickly than complement-fixing antibody.
The incidence of infective drug resistance in strains ofEscherichia coliisolated from diseased human beings and domestic animals
Authors: Smith H. Williams
Published: May 2009

A high incidence of drug resistance, mostly of the infective type, was found amongst strains ofEscherichia coliisolated from human beings suffering from neonatal diarrhoea, calves and lambs suffering from neonatal diarrhoea or bacteraemia, pigs suffering from neonatal or post-weaning diarrhoea or bowel oedema and from fowls suffering from ‘coli-septicaemia’. The strains from the human beings, pigs and fowls, and those from calves and lambs suffering from bacteraemia, belonged to serotypes generally accepted as being pathogenic for these species.

Complex drug-resistance patterns were a common feature, particularly amongst the human and calf strains, some being resistant to six drugs. Only two drugs, polymyixin and nalidixic acid, were active on all the strains.

The incidence of drug resistance amongst pig strains was twice as great in those isolated in 1965 as in those isolated in 1960–62; neomycin and furazolidone resistance was found amongst the 1965 strains but not amongst the 1960–62 strains.

Infective resistance was easily demonstrated; tetracycline resistance was transferred from one tetracycline-resistant strain ofE. colito 37 of 38 tetracycline-sensitive strains at the first attempt.

Most ampicillin, streptomycin, tetracycline, chloramphenicol, neomycin and sulphonamide resistance was of the infective type; the furazolidone resistance in all of eight strains studied was not shown to be infective.

In the experiments to demonstrate the presence of infective resistance the level of drug resistance was usually found to be the same in donor and recipient strains.
Further studies with a diphtheria–tetanus–poliomyelitis vaccine
Authors: Haire Margaret , Dane David S. , Dick George , Briggs E. Moya , Connor T. J.
Published: May 2009

The efficiency of a diphtheria, tetanus, poliomyelitis vaccine in inducing a serological response after a three-dose primary course of immunization was tested in thirty-nine children aged 5 and 6 years and found to be satisfactory. This vaccine had previously been shown to be suitable for use as a single dose reinforcing vaccine for children of this age who had been immunized in infancy. It is suggested that all children might receive one dose of the vaccine at the time they enter school, and then those who have not been immunized before should receive a further two suitably spaced doses to complete their course of primary immunization.
Acquisition ofStaphylococcus aureusby patients undergoing cytotoxic therapy in an ultra-clean isolation unit
Authors: Andrews H. J. , Bagshawe K. D.
Published: May 2009

The twenty-four young women and one man treated in an ultra-clean isolation ward should have had a low incidence of staphylococcal infection on grounds of age, sex and clean environment alone. However, they apparently acquired new strains ofStaph. aureusat the rate of 4·7/100 patient weeks (3·9 multiple resistant strains/100 patient weeks) from the sixth week after admission onwards.

Environmental factors contributing to infection included introduction of resistant strains by the patients on admission, contact between patients in the unit, and failure to eliminate nasal carriage in staff and patients.

Host susceptibility was increased by malignancy, and by antibiotic and cytotoxic therapy. The nasal carriage rate ofStaph. aureuswas significantly greater for patients with repeated episodes of leucopenia induced by cytotoxic drugs.
The isolation and characterization of foot-and-mouth disease virus from clinically normal herds of cattle in Botswana
Authors: Hedger R. S.
Published: May 2009

The results of a survey of the foot-and-mouth disease carrier state in three localities of an FMD enzootic area of Botswana are presented. The collection, storage and handling of the samples is mentioned and the isolation of virus on calf thyroid monolayer tissue cultures is described. Type SAT 3 virus was isolated from up to 20% of the animals sampled at periods between 7 and 12 months after natural infection. Sera were tested for all the animals from which virus was recovered and compared with similar numbers of sera from virus-negative animals. No correlation was found between the carrier state and serum antibody titres.

Antigenic studies are described which indicated not only an antigenic variation of some carrier viruses isolated from the outbreak strain but also antigenic differences between strains of carrier virus from different animals in the same herd. There was no evidence at the time of sampling of the persistence as carrier virus of the attenuated vaccine strains of FMDV used previously in the cattle sampled.

The results suggest that transference of carrier virus from animal to animal may occur in the absence of clinical infection.
The serum opacity reaction ofStreptococcus pyogenes: frequency of production of streptococcal lipoproteinase by strains of different serological types and the relationship to M protein production
Authors: Top Franklin H. , Wannamaker Lewis W.
Published: May 2009

The serum opacity reaction (SOR) is produced by some streptococci of group A, but not by streptococci of groups B, C, D, F and G. The production of this reaction was found to be closely related to serotype as determined by M and T antigens. The SOR of an individual strain was found to be consistently stable over a period of time both in strains maintained in the laboratory and in strains isolated sequentially from individual patients following streptococcal infections. Strains for which the demonstration of an M-antigen by the precipitin method was difficult or impossible in general produced a SOR, while strains more easily typable generally failed to produce this reaction. Laboratory selected variants of type 12 strains showed an inverse relationship between M protein and lipoproteinase production, whereas M positive and M negative variants of other serotypes showed no variability with respect to lipoproteinase production.
Comparison of MacConkey broth, Teepol broth and glutamic acid media for the enumeration of coliform organisms in water
Authors:   By the Public Health Laboratory Service Standing Committee on the Bacteriological Examination of Water Supplies
Published: May 2009

Oxoid dehydrated MacConkey broth was compared with laboratory prepared MacConkey broth, Teepol broth and three modifications of glutamic acid media, by participants in eleven laboratories. A variety of chlorinated and unchlorinated water samples were used. The Oxoid MacConkey broth was shown to be a satisfactory standard for comparison. Teepol broth was found to be a satisfactory alternative to MacConkey broth. Gray's improved glutamate medium was shown to be the best of the glutamate media and it gave results superior in most respects to MacConkey broth. In particular more Escherichia coli were obtained as well as more coliform organisms. Organisms surviving marginal chlorination were recovered more readily. Growth was sometimes slower than in MacConkey broth but this could possibly be improved by closer attention to pH adjustment and mineral composition.
A bacteriological assessment of meat, offal and other possible sources of human enteric infections in a Bantu township
Authors: Richardson N. J. , Burnett Gillian M. , Koornhof H. J.
Published: May 2009

1. From the Municipal abattoir, specimens of liver, spleen, lymph node, surface meat, bile and faeces from a sheep and a bovine, were examined fortnightly for 14 months for the presence of possible pathogenic bacteria. The results suggest that slaughtering procedures are satisfactory.

2. Offal, consisting mainly of tripe and intestine, is eaten in large quantities by the Bantu population and is both nutritious and economical. The high incidence of salmonella isolations in the tripe (48%) and intestines (29%), and faecalE. coliandCl. welchii, show that this commodity is distributed in an inadequately cleansed condition.

3. FaecalE. coliwas isolated from 86% of samples of sour milk collected from street pedlars.

4. Dog faeces collected from the township pavements yielded 21% salmonellas, and faeces from fowls sold live by shopkeepers 14%.

5. From the offal specimens,S. typhimurium(23%) andS. london(18%) were the salmonella types most frequently isolated.S. dublinwas isolated on only one occasion.

6. Throughout the survey no shigellas were isolated.

7. The significance of theCl. welchii, coagulase positiveStaphylococcus aureusandB. cereusisolations from the various specimens tested is not known.

8. It is emphasized that although there is a definite need for improved treatment of the offal before distribution to the consumer, the resulting increase in cost must not be such as to deprive the population of this important source of protein.

We wish to thank the Director of this Institute, Professor J. H. S. Gear, for permission to publish this paper, Dr P. J. Meara, Director of the City of Johannesburg Abattoir and Livestock Market Department for facilities granted, and Mr C. J. Franklin for collecting all the abattoir specimens. Our thanks are also due to Dr A. Smith, Medical Officer of Health, and Dr I. H. F. Spencer of the Johannesburg City Health Department for help and advice; to Mr A. J. MacG. Bryce for collecting all the specimens from the Soweto township; to Mrs Leonie Jonk for typing the salmonella organisms and Mr R. G. Robinson for investigating the micro-organisms' sensitivity to antibiotics.
Further studies on the antibiotic resistance ofShigella sonnei: I. Transferable antibiotic resistance
Authors: Davies Joan R. , Farrant W. N. , Tomlinson A. J. H.
Published: May 2009

The incidence of antibiotic resistant strains ofSh. sonneiisolated in the London area is described. Strains were tested for their ability to transfer resistance to Most strains were resistant to sulphonamide and this resistance was transferable.

An increasing proportion of strains was resistant to 800 µg./ml. of streptomycin, but transferable streptomycin resistance was less common and often associated with tetracycline resistance.

The proportion of strains resistant to tetracycline fluctuated but this resistance was always transferred.

Ampicillin resistance was common; only those strains resistant to 500µg./ml. transferred this resistance.

Resistance to other antibiotics was very rare.
Chick embryo lethal orphan (CELO) virus as a possible contaminant of egg-grown virus vaccines
Authors: Oxford J. S. , Potter C. W.
Published: May 2009

The inactivation kinetics of CELO virus were studied in the presence of 1/4000 formaldehyde. Inactivation of the virus by formaldehyde at 4° C. was not complete after 14 days incubation. Formaldehyde inactivation at 36° C., however, was rapid and no virus was detected after 24 hr. incubation.

Neutralizing antibody to CELO virus was detected in 20–88% of sera tested from five flocks of hens. This suggested dissemination of the virus in England and Scotland. However, no CELO virus neutralizing antibody at a serum dilution of 1/8 was detected in 142 normal human sera or in 229 sera from persons who had been immunized with egg grown, inactivated influenza virus vaccine.

We would like to thank Professor C. H. Stuart-Harris and Drs J. E. Wilson, D. A. Martin and D. Breeze for their help and their criticisms of the manuscript.

Dr G. C. Schild kindly supplied a number of the human sera used in the study. The study was financed in part by the National Fund for Research in Poliomyelitis and other Crippling Diseases and by the British Empire Cancer Campaign.
Importance of the carrier state as a source of Staphylococcus aureus in wound sepsis
Authors: Calia Frank M. , Wolinsky Emanuel , Mortimer Edward A. , Abrams Jerome S. , Rammelkamp Charles H.
Published: May 2009

The relationship of pre-operative nasal and skin carriage of Staphylococcus aureus to wound colonization and sepsis was studied in 269 patients. Thirty-seven per cent of 96 carriers developed wound colonization as compared to 16 % among non-carriers (a statistically significant difference). The wound sepsis rates were 17 % and 9 % respectively. The combination of nasal and skin carriage was an important factor, since the sepsis rate among skin carriers (most of whom were nasal carriers as well) was 22%. Among carriers, the homologous strain was recovered from the majority of wound colonizations and from all instances of wound sepsis. A carrier strain also was recovered from 52% of the wounds colonized and from 50% of septic wounds in the entire study group. Profuse nasal carriage resulted in a significantly greater number of septic wounds (31%) than sparse carriage (9%). Wound cultures before closure, and skin from the initial incision site only once yielded a patient's carrier strain or a strain of Staph. aureus that was later recovered from the wound. The results indicate that measures designed to control the carrier state or to isolate the wound from the external environment should reduce wound sepsis by approximately one half.

Excellent technical aid was furnished by Eleanor Ford, R. N., Edith E. Silverman, Adrienne Marus, M. S., and Patricia Welch.