bluuebunny/crossref_metadata_2025 huggingface dataset:
Poultry-borne salmonellosis in Scotland
Authors: Reilly W. J. , Forbes G. I. , Sharp J. C. M. , Oboegbulem S. I. , Collier P. W. , Paterson G. M.
Published: May 2009

Between 1980–5, 224 outbreaks of salmonellosis associated with poultry-meat were reported in Scotland. In total 2245 persons were affected, 12 of whom died. Twenty-one salmonella serotypes were identified from those affected, while 33 serotypes were isolated from poultry during routine monitoring and disease investigation. Existing measures to prevent the spread of salmonellae within poultry flocks and processing plants are failing. It is suggested that irradiation of poultry-meat may be the only effective method of reducing the public health problem of poultry-borne salmonellosis.
Isolation of African swine fever virus from ticks of the Ornithodoros moubata complex (Ixodoidea: Argasidae) collected within the African swine fever enzootic area of Malawi
Authors: Haresnape J. M. , Wilkinson P. J. , Mellor P. S.
Published: May 2009

Ticks of the Ornithodoros moubata complex were collectedfrom domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of African swine fever (ASF) virus. Collections were made in 9 of the 24 districts of Malawi, these being primarily the districts in which O. moubata is most numerous. ASF virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in Mchinji district where ASF outbreaks had recently occurred. Mchinji district is in the centre of a large ASF enzootic area which stretches into other districts of Malawi and also into Zambia and Mozambique. The high titre of virus in some of the ticks demonstrates that O. moubata can act as a virus reservoir and potential vector of disease in the field situation in Malawi.
Detection of specific IgM in varicella and herpes zoster by antibody-capture redioimmunoassay
Authors: Kangro H. O. , Ward A. , Argent S. , Heath R. B. , Cradock-Watson J. E. , Ridehalgh Margaret K. S.
Published: May 2009

A simple and sensitive M antibody-capture radioimmunoassay (MACRIA) is described which utilizes crude commercial VZV antigen and a single monoclonal anti-VZV antibody. This was compared to the immunofluorescence (IF) test for IgM antibody and was used to study IgM responses in sera from 261 patients with varicella and 220 patients with herpes zoster.

With MACRIA, IgM antibodies were detected in all patients with varicella. The IgM antibodies appeared shortly after onset of rash, reached peak levels between 1 and 4 weeks after onset and then declined to low or undetectable levels in most, though not all, patients after 3 months. IgM antibodies were also detected in 98·2% of patients with herpes zoster, but the levels of IgM were significantly lower than after varicella and there was wider individual variation both in magnitude and duration of the IgM responses, in some cases only lasting 2–3 weeks.

Comparison between MACRIA and IF showed good agreement in the detection of IgM antibodies following varicella. Discordant results were obtained with 13% of sera. of which 81% were taken either early or late after onset of rash and contained very low IgM levels. In contrast, 62 (28%) of the 220 sera from patients with zoster gave discordant results in the two tests, all except five being MACRIA positive but IF-negative. The largest proportion of discordant results were obtained with sera taken more than 3 months after onset of rash, but 18 (29%) contained high IgM levels and were taken during the period of peak IgM responses. The diagnostic applications of the VZV MACRIA are discussed.
Persistent enteral infections with adenovirus types 1 and 2 in infants: no evidence of reinfection
Authors: Adrian T. , Schäfer G. , Cooney M. K. , Fox J. P. , Wigand R.
Published: May 2009

Isolates of adenovirus types 1 and 2, obtained from 11 infants with prolonged faecal excretion (up to 515 days), were compared by DNA restriction analysis with seven standard endonucleases which recognize hexanucleotides and two additional endonucleases which recognize tetranucleotides. In all instances identical genome types were identified in isolates obtained early and late after infection. Our interpretation of these data is that a chronic persistent infection occurred in these children. and not a reinfection with the same serotype.
The distribution of African swine fever virus isolated fromOrnithodoros moubatain Zambia
Authors: Wilkinson P. J. , Pegram R. G. , Perry B. D. , Lemche J. , Schels H. F.
Published: May 2009

African swine fever (ASF) has been reported in the Eastern Province of Zambia since 1912 and is now considered to be enzootic there. A survey of the distribution of ASF virus in Zambia was carried out by virus isolation fromOrnithodoros moubataticks collected from animal burrows in National Parks and Game Management Areas in northern, eastern, central and southern Zambia. ASF virus was isolated from ticks in all areas examined. The prevalence of infection inO. moubatawas between 0·4% in South Luangwa National Park and 5·1% in Livingstone Game Park and mean infectious virus titres ranged from 103–4HAD50/tick in Kakumbe Game Management Area to 105·9HAD50/tick in Chunga and Nalusanga Game Management Areas. The prevalence of infection in adult ticks was between 4·7% and 5·3% in all areas examined except Sumbu National Park and Livingstone Game Park, where the prevalence was 15·1% and 13·2% respectively in adult ticks. The ratio of infected females to males for all the infected adult ticks in all areas of Zambia was 3·2:1.
Hospital-acquired infection with methicillin-resistant and methicillin-sensitive staphylococci
Authors: Law M. R. , Gill O. N.
Published: May 2009

In-patients at a London hospital over one year from whom the south-east England strain of ‘epidemic’ methicillin-resistant Staphylococcus aureus (MRSA) was isolated were compared with in-patients with strains of methicillin-sensitive Staphylococcus aureus (MSSA). MRSA were virtually entirely hospital-acquired; isolates before 10'days were uncommon and related to recent previous admission. Thereafter first isolates occurred at a fairly constant daily rate of about 1·9 per 1000 in-patients. Acquisition of MSSA after more than 4 days in hospital occurred at a similar constant rate. Such strains were less likely to be penicillin-sensitive than strains isolated in the first 4 days after admission (11 vs. 22%) and were considered to be hospital-acquired. The single MRSA strain caused 40 infections in a year, about half of all hospital-acquired staphylococcal infections. Patients prescribed anti-staphylococcal antibiotics and patients with indwelling cannulae both had about a ninefold increased risk of acquiring MRSA. There was no reciprocal increase in MSSA infections after control measures had substantially reduced the number of MRSA infections.
Exposure to Legionellaceae at a hot spring spa: a prospective clinical and serological study
Authors: Bornstein N. , Marmet D. , Surgot M. , Nowicki M. , Arslan A. , Esteve J. , Fleurette J.
Published: May 2009

Following the occurrence of five cases of Legionnaires' disease among patients and therapists at a French hot spring spa, a series of cleansing procedures and an epidemiological study were undertaken. During a 3-month period, the spring water was repeatedly sampled. Serum samples were taken from 689 randomly selected patients, 230 therapists, 134 administrative staff and a control group of 904 blood donors.

Legionellaceae were present in the spring water at concentrations of 103–1055colony forming units/1. Fifteen different species or serogroups were isolated withLegionella pneumophilaserogroups 3 and 1 predominating. No clinical cases of Legionnaires disease were observed during the study. However, 11% of the therapists and 5% of the patients either had a high titre of antibody (≥256) to at least one species or serogroup or seroconverted during the study. Mean antibody titres in the three study groups were significantly higher than those in the blood donors against 11 of the 32 legionella antigens tested. Nine of these 11 antigens corresponded to species or serogroups isolated from the spring water. The highest mean antibody titres in all three study groups were againstL. pneumophilaserogroup 3, the most common legionella in the spring water.

These findings have important implications for the maintenance of adequate standards of hygiene, bacteriological sampling and clinical surveillance in this and similar establishments.
Campylobacter jejuniisolations from Mexican and Swedish patients, with repeated symptomatic and/or asymptomatic diarrhoea episodes
Authors: Sjögren E. , Ruiz-Palacios G. , Kaijser B.
Published: May 2009

The presence of differentCampylobacter jejuniserotypes in Swedish patients with diarrhoea and in Mexican patients with or without diarrhoea was investigated with special reference to repeated isolations during the course of infection and to symptomatic and asymptomatic episodes. The study included 136C. jejuniisolates from 62 Mexican children and 173 isolates from 68 Swedish patients. The bacteria were serotyped for heat-stable (HS) and heat-labile (HL) antigen.
Campylobacter jejuniandCampylobacter colidiarrhoea in rural and urban populations in Yugoslavia
Authors: Popović-Uroić T.
Published: May 2009

During a 4-month period during the summer of 1985, campylobacters were isolated from 338 (16·3%) of 2080 patients with acute diarrhoea attending the University Hospital of Infectious Diseases in Zagreb. Of these isolates 220 (64·1%) were Campylobacter jejuni and 118 (34·9%) wereC. coli. The patients were drawn from three residential zones in and around Zagreb: inner city, peripheral city and rural. Incidences of campylobacter diarrhoea ranged from 71 per 100 000 per year in inner city residents to 99 per 100 000 per year in the rural residents. Most infections were in young children; the incidence in infants ranged from 800 to 2500 per 100 000 per year in the inner city and rural zones respectively. The isolation rate from faecal specimens of infants from the rural zone was 61%. The ratio of isolation rates in males and females (all ages) was 1·1:1, but in infants it was 0·7:1 and in patients over the age of 65 years it was 0·4:1. The incidence ofC. coliin the rural zone was four times that in the inner city and twice that in the peripheral zone.

This survey shows that campylobacter infection in Zagreb has distinctive epidemiological features. The transmission of infection appears to be midway between that found in industrialized and developing countries, and there is an unexplained excess ofC. coliinfection.
Longitudinal study of rotavirus infections among children from Belém, Brazil
Authors: Linhares A. C. , Gabbay Y. B. , Freitas R. B. , Travassos da Rosa E. S. , Mascarenhas J. D. P. , Loureiro E. C. B.
Published: May 2009

From December 1982 to March 1986 a group of 80 children between 0 and 3 years old who lived in the peripheral area of Belém, Brazil, were followed up for episodes of diarrhoea. A total of 441 diarrhoeal episodes were recorded and 36 (8·2%) were associated with rotavirus. This agent was the only pathogen in 50% of rotavirus-related episodes of acute diarrhoea, and strains were characterized by analysis of RNA in polyacrylamide gels. Forty-one belonged to subgroup II (long pattern) and five to subgroup I. Reinfections by rotavirus were noted in 12 children involving either the same or different subgroups. Ten distinct electrophoretypes were detected in the study period and the predominant one had the ‘1N2L’ profile. The cumulative age-specific attack rate for diarrhoea reached 2–8 by the end of the first year of life; a frequency of 2–3 episodes of diarrhoea per child per year was observed throughout the complete investigation. In comparing the age-specific attack rates for diarrhoea between breast-fed and bottle-fed children, a peak at 6 months of age was noted in the former, and at 1 month in the latter. A comparison by Fischer's exact test (P = 0·21) provided no evidence for protection against clinical rotavirus disease by maternal milk. By the same test, however (P = 0·021), we found significant evidence that early rotavirus infections were more likely to be asymptomatic and that infections after 4 months were more likely to be symptomatic. The clinical picture in children with rotavirus-related diarrhoea was more severe than in those suffering from acute diarrhoea due to another agent.
Seroepidemiological study of the transmission of the mumps virus in St Lucia, West Indies
Authors: Cox M. J. , Anderson R. M. , Bundy D. A. P. , Nokes D. J. , Didier J. M. , Simmons I. , Catherine J.
Published: May 2009

A seroepidemiological study of the prevalence of mumps virus specific antibodies reveals a pattern of endemic peristence on the island of St Lucia in the West Indies. In the unvaccinated population the proportion seropositive rose rapidly in the child age classes to attain a stable plateau close to unity in value in the teenage and adult age groups. The average age at infection was estimated to be between 3 and 4 years of age and the average duration of detectable levels of maternally derived antibodies was approximately 3 months. Analyses based on mathematical models of the transmission dynamics of the virus suggest that in excess of 75% of each cohort of 1-to 2-year-old children must be effectively immunized to eliminate mumps virus transmission. A mumps radial haemolysis test, developed for quantitative measurements of antibody, is discussed.
Epidemiology
Authors: Noble W. C.
Published: May 2009

William Norman Pickles (1885–1969) was, for most of his life, a general practitioner in the village of Aysgarth, Wensleydale in the North of England, a relatively remote area in the early part of this century with many of the doctors' visits made on horseback or on an ancient motorcycle. The story of Pickles' life, how he became, among other honours, the first President of the Royal College of General Practitioners, is told in Pemberton's book Will Pickles of Wensleydale. It may seem curious that Pickles, a country GP, should rank with other great men in epidemiology: Jenner who worked on smallpox, Budd on typhoid fever, Snow on cholera, yet it was the remoteness of his practice combined with his own acute observation and accurate recording that enabled him to contribute so significantly to epidemiology.
Cyclical patterns and predictability in infection
Authors: Noah N. D.
Published: May 2009

Many infections, especially viral infections, show a certain periodicity which can be wholly or partly predictable. It is important to be able to recognize these patterns because anticipating changes in incidence should lead to better diagnosis, treatment and control of infection. In this review patterns of some viral and other infections in England and Wales which have been observed from laboratory reports over a period of 21 years, from 1967 to 1987, are described.
Transmissible mupirocin resistance inStaphylococcus aureus
Authors: Rahman Mary , Noble W. C. , Cookson B.
Published: May 2009

The spread of two strains ofStaphylococcus aureuswith high level resistance to mupirocin is described. The resistance proved to be easily transferred to otherS. aureusstrains by filter mating experiments and on the skin of mice. No plasmid band corresponding to the resistance could be demonstrated by agarose gel electrophoresis or by caesium chloride gradient centrifugation but cleavage of ‘chromosomal’ DNA from resistant recipients showed bright bands of DNA absent from sensitive controls.
Natural or vaccine-induced antibody as a predictor of immunity in the face of natural challenge with influenza viruses
Authors: Davies J. R. , Grilli E. A.
Published: May 2009

A study of influenza in residential schools provided the opportunity to assess the significance of antibody as a predictor of immunity. Five hundred and fifty-six pupils from 8 schools were included in the investigations, and the outcome for these children in 27 naturally occurring outbreaks of influenza was analysed. The outbreaks comprised 5 caused by strains of influenza A H3N2, 10 caused by strains of influenza A H1N1, and 12 caused by strains of influenza B. On 8 occasions a second outbreak of the same serotype occurred in a school.

There was a general correlation between the presence of antibody to the outbreak strain and protection from infection. For each of the three influenza virus serotypes the infection rate in those with no detectable antibody was approximately 80%. Those with past experience of the virus but no antibody to the outbreak strain experienced lower infection rates (62% overall) but the infection rates were lowest in those with intermediate and high level antibody to the challenge strain (18% overall).

Vaccine was used by three of the schools. The effect of antibody derived from recent experience, either natural or vaccine-induced, on subsequent challenge with a drifted strain i.e. one showing antigenic drift away from the previous strain, was compared. Intermediate or high level antibody to the challenge strain in those who had experienced a recent natural infection was associated with a low infection rate (9%). A similar level of antibody produced in response to vaccination was associated with a significantly higher infection rate (23%:P 0-025). Among the vaccinees who had produced such antibody the infection rate was highest (32%) in those who had responded to vaccine in the presence of antibody to the vaccine strain.

The evidence from this study indicates that whilst antibody surveys of populations may provide some information about susceptibility to challenge with new strains of influenza viruses, the cirucumstances of the induction of the antibody affect its value as a predictor of immunity.
Viruses in acute gastroenteritis in children in Pune, India
Authors: Bright Singh P. , Sreenivasan M. A. , Pavri Khorshed M.
Published: May 2009

A 2-year study from January 1981 to December 1982 was undertaken to determine the role of viruses in the causation of diarrhoea in hospitalized children in Pune, Maharashtra State, India. The stool samples of 426 children (213 diarrhoeal and 213 non-diarrhoeal controls) were investigated by electron microscopy and ELISA for the presence of viruses. Six morphologically distinct viruses were visualized: rotavirus, coronavirus-like particles (CVLP), adenovirus, astrovirus, calicivirus and small round virus-like particles (SRV). Rotavirus was detected in 28·6% of the diarrhoea! patients and in 1·4 % of the controls. The frequency of infection with rotavirus was highest in the children aged less than 5 years. The mean age of rotavirus-positive patients was 11 months. Although rotavirus was detected in almost every month, there has a seasonal trend for colder months when CVLP cases were fewest. However, the prevalence of CVLP was greater in the control group (23–0%) rather than in those with diarrhoea (8–9%). In the control group, CVLP were detected more frequently during the summer months. An inverse relationship between CVLP and rotavirus was observed in children. Adenovirus, astrovirus, calicivirus and SRV were detected in a small proportion of children with and without clinical symptoms of gastroenteritis.
Enhancement of the infectivity ofFusobacterium necrophorumby other bacteria
Authors: Smith G. R. , Till D. , Wallace L. M. , Noakes D. E.
Published: May 2009

Necrobacillosis is caused byFusobacterium necrophorum(FN), but other organisms are often present in the lesions. Their possible role was studied in experiments made with a virulent FN strain which, by itself, produced fatal necrobacillosis in mice provided that large doses ( > 106organisms, subcutaneously) were given. Mice were inoculated subcutaneously with FN suspended in sub-lethal doses (0·1 ml) of undiluted or diluted broth cultures of other bacteria. Undiluted culture of a strain ofEscherichia colireduced the infective dose of FX to < 10 organisms: in the necrobacillosis lesions that developed, fusobacteria greatly outnumberedE. coli. A heat-killed preparation or sterile filtrate ofE. coliculture had little if any effect on FN.Citrobacter freundiiand comparativelv small numbers ofCorynebacterium (Actinomyces) pyogenesproduced effects similar to that ofE. coli. An α-haemolvtic streptococcus.Pseudomonas aeruginosa.Bacteroides fragilisandFusobacterium nudeatumalso enhanced the infectivity of FN. though less strikingly thanE. coli. FN increased the persistence invivoof the α-haemolytic streptococcus andB. fragilis, and enabled the latter to multiply profusely.
Methicillin-resistant Staphylococcus aureus from China characterized by digestion of total DNA with restriction enzymes
Authors: Hall L. M. C. , Jordens J. Z. , Wang F.
Published: May 2009

A series of clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) from two hospitals in China was examined. Fragment patterns obtained by digestion of total cellular DNA with restriction enzymes were used to characterize the isolates, in combination with phage-typing, antibiotic resistance profile, and plasmid profile. Digestion of total cellular DNA with restriction enzymes was most useful in discriminating between isolates and yielded additional information on the relatedness of non-identical isolates. In one hospital a single strain, resistant to a large number of antibiotics, had apparently become endemic. In the second hospital a number of distinct but related strains were present. The isolates were also related but not identical to the strain of MRSA endemic at the London Hospital.
Legionnaires' disease and the sick-building syndrome
Authors: O'Mahony M. , Lakhani A. , Stephens A. , Wallace J. G. , Youngs E. R. , Harper D.
Published: May 2009

In October 1985, six cases of legionnaires' disease were associated with a police headquarters building. Four were amongst staff who worked in or visited the communications wing of the headquarters and two cases occurred in the local community. A case-control study implicated the operations room of the communications wing as the main area associated with infection. This wing was air-conditioned and smoke tracer studies showed that drift from the exhaust as well as from the base of the cooling tower entered the main air-intake which serviced the air-conditioning system.Legionella pneumophilaserogroup 1 subgroup pontiac was isolated from water and sludge in the cooling tower pond. Contaminated drift from the top of the cooling tower was probably responsible for the two community cases. An additional discovery was that symptoms suggestive of the sick-building syndrome were associated with working in this wing.
Myxomatosis in farmland rabbit populations in England and Wales
Authors: Ross J. , Tittensor A. M. , Fox A. P. , Sanders M. F.
Published: May 2009

The overall pattern and consequences of myxomatosis in wild rabbit populations were studied at three farmland sites in lowland southern England and upland central Wales between 1971 and 1978. When results from all years were combined, the disease showed a clear two-peaked annual cycle, with a main autumn peak between August and January, and a subsidiary spring peak during February to April.

Rabbit fleas, the main vectors of myxomatosis in Britain, were present on full-grown rabbits in sufficient numbers for transmission to occur throughout the year, but the observed seasonal pattern of the disease appeared to be influenced by seasonal mass movements of these fleas. However other factors were also important including the timing and success of the main rabbit breeding season, the proportion of rabbits which had recovered from the disease and the timing and extent of autumn rabbit mortality from other causes.

Significantly more males than females, and more adults and immatures than juveniles, were observed to be infected by myxomatosis. Only 25–27% of the total populations were seen to be infected during outbreaks. Using two independent methods of calculation, it was estimated that between 47 and 69% of infected rabbits died from the disease (much lower than the expected 90–95% for fully susceptible rabbits with the partly attenuated virus strains that predominated). Thus it was estimated that 12–19% of the total rabbit populations were known to have died directly or indirectly from myxomatosis.

Although the effects of myxomatosis were much less than during the 1950s and 1960s, it continued to be an important mortality factor. It may still have a regulatory effect on rabbit numbers, with autumn/winter peaks of disease reducing the numbers of rabbits present at the start of the breeding season.
A time series analysis of the rabies control programme in Chile
Authors: Ernst S. N. , Fabrega F.
Published: May 2009

The classical time series decomposition method was used to compare the temporal pattern of rabies in Chile before and after the implementation of the control programme. In the years 1950–60, a period without control measures, rabies showed an increasing trend, a seasonal excess of cases in November and December and a cyclic behaviour with outbreaks occurring every 5 years. During 1961–1970 and 1971–86, a 26-year period that includes two different phases of the rabies programme which started in 1961, there was a general decline in the incidence of rabies. The seasonality disappeared when the disease reached a low frequency level and the cyclical component was not evident.
Excretion ofYersiniaspp. associated with consumption of pasteurized milk
Authors: Greenwood M. H. , Hooper W. L.
Published: May 2009

Yersinia enterocoliticabiotype 1, serotype O.10K was isolated from 19 patients in the paediatric wards of a district general hospital over a period of 3 months. Fifteen cases were patients on the medical ward. Shortly afterwards.Y. enterocoliticabiotype 1, serotype 0.6,30 was isolated from a further 17 patients on this ward in 1 month. The same serotypes ofY. enterocoliticawere isolated from the pasteurized milk supplied to the ward. Epidemiological evidence indicated that contaminated pasteurized milk was the source of the yersinia organisms exereted by the patients.
Reduction in faecal excretion ofSalmonella typhimuriumstrain F98 in chickens vaccinated with live and killedS. typhimuriumorganisms
Authors: Barrow P. A. , Hassan J. O. , Berchieri A.
Published: May 2009

Chickens given orally at 4 days of age a smooth spectinomycin resistant mutant (Spcr) ofSalmonella typhimuriumstrain F98 excreted the organism in their faeces for approximately 4 weeks. Following oral administration of a nalidixic acid resistant (Nalr) mutant of the same strain 4 weeks later when later when the chickens had virtually cleared themselves of the first infection, these chickens excreted far fewer salmonella organisms and for a shorter time than did a previously uninfected control group of chickens which were infected at the same time with the Nalrmutant. Chickens inoculated intramuscularly at 4 days developed a similar immunity to challenge and also excreted the immunizing strain in their faeces. In contrast intramuscular inoculation or incorporation into the food of formalin-killedS. typhimuriumorganisms had little lasting effect on the faecal excretion of the challenge strain. Two attenuated mutants of strain F98 Nalrwere produced: one was a rough strain produced by lytic bacteriophage and the other was anaro Aauxotrophic mutant which had been cured of the 85 kilobase–pair virulence–associated plasmid. These mutants were avirulent for chickens, mice, calves and man and when ingested by human volunteers did not persist in the faeces. When inoculated intramuscularly into chickens they produced an early reduction in faecal excretion of the challenge strain (Spcr) which was not maintained. Oral administration of both strains produced reductions in faecal excretion of the challenge strain. This was much more noticeable with the rough strain which was itself excreted for a much longer period than the parent strain.
Prevalence of verocytotoxigenicEscherichia coliin ground beef, pork, and chicken in southwestern Ontario
Authors: Read S. C. , Gyles C. L. , Clarke R. C. , Lior H. , McEwen S.
Published: May 2009

Samples of ground beef (225), pork (235) and chicken (200) were randomly selected from meat processing plants in the southwestern Ontario area. Supernatants of broth cultures of the samples were tested for verocytotoxins using a Vero cell assay. Neutralization of cytotoxic activity using antisera specific for three types of verocytotoxin (Verotoxin 1, Verotoxin 2 and Shiga-like toxin II) was performed on positive samples. Isolation of verocytotoxigenicEscherichia coli(VTEC) was attempted from positive samples. VTEC were confirmed asE. colibiochemically, tested for drug resistance, and serotyped. Based on neutralization studies, the prevalance of VTEC in beef and pork was at least 36·4% and 10·6%. respectively. This is much higher than has been reported from a survey of retail meats in which a method designed to detect onlyE. coliO 157.H7 was used. Isolations of VTEC were made from 10·4 % of the beef samples and 3·8 % of the pork samples. No VTEC were recovered from the chicken samples. The majority of VTEC isolates were susceptible to commonly used antimicrobial agents. A number of the serotypes of the VTEC isolates recovered have been associated with human disease; however, no VTEC of serotype O 157.H7 were isolated.
International increase in Salmonella enteritidis: A new pandemic?
Authors: Rodrigue D. C. , Tauxe R. V. , Rowe B.
Published: May 2009

Over the past 5 years Salmonella enteritidis infections in humans have increased on both sides of the Atlantic ocean. The WHO salmonella surveillance data for 1979–87 were reviewed and show that S. enteritidis appears to be increasing on at least the continents of North America, South America, and Europe, and may include Africa. S. enteritidis isolates increased in 24 (69%) of 35 countries between 1979 and 1987. In 1979, only 2 (10%) of 21 countries with reported data reported S. enteritidis as their most common salmonella serotype; in 1987, 9 (43%) of 21 countries reported S. enteritidis as their most common serotype; 8 (89 %) of 9 were European countries. Although the reason for the global increase is not yet clear, investigations in individual countries suggest it is related to consumption of eggs and poultry which harbour the organism.
Binding of IgA and/or IgG is a common property among clinical isolates of group A streptococci
Authors: Lindahl G. , Stenberg L.
Published: May 2009

Certain strains of group A streptococci are known to bind IgA and/or IgG via a cell surface receptor, which may act as a virulence factor. The distribution of such receptors among routine clinical isolates was studied, using a total of 225 strains and an assay based on the binding of radiolabelled immunoglobulins. Among 194 throat strains isolated during three different time periods in two different geographical areas of Sweden, 82% showed significant binding of IgA and/or IgG. Studies on 31 septicaemia strains, isolated over a period of more than 8 years, showed binding for 84% of the isolates. The binding strains were of several different T-types and could be subdivided into two groups, those binding both IgA and IgG and those binding IgG only. These data show that binding of IgA and/or IgG is a very common property among clinical isolates of group A streptococci.
Investigation of a pseudo-outbreak of ‘Pseudomonas thomasii’ in a special-care baby unit by numerical analysis of SDS–PAGE protein patterns
Authors: Costas M. , Holmes B. , Sloss L. L. , Heard S.
Published: May 2009

Forty-two cultures of pseudomonas comprising 28 clinical isolates from a pseudo-outbreak on a Special-Care Baby Unit and 14 reference strains, including 9 type strains, of variousPseudomonasspecies, were characterized by one-dimensional sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) of whole-cell proteins. The protein patterns were highly reproducible and were used as the basis for a numerical analysis which divided the strains into 9 phenons. Two of the 28 clinical isolates were identified by biochemical tests asP. pickettiiand their identification was confirmed by SDS–PAGE as they fell in the same phenon as the type strain of the species. The remaining 26 isolates, which could not be identified on phenotypic tests, fell in the same phenon as three reference strains of ‘P. thomasii’. The protein patterns provided the first clear evidence thatP. pickettiiand ‘P. thomasii’ were separate taxa and that the ‘outbreak’ was polymicrobial in origin, in line with the probable aqueous source of contamination. We conclude that high-resolution SDS–PAGE of proteins provides an effective method of identifying and differentiating pseudomonads, especially where this cannot be done adequately using conventional biochemical tests.
Determination of colonization resistance of the digestive tract by biotyping of Enterobacteriaceae
Authors: Apperloo-Renkema H. Z. , Van der Waaij B. D. , Van der Waaij D.
Published: May 2009

In studies concerning the effect of antibiotics on faecal microflora, Colonization Resistance is an important parameter. Colonization Resistance correlates inversely with the number of different biotypes of Enterobacteriaceae isolated from faecal samples. Nine healthy volunteers were studied during 6 weeks, in order to determine the natural variation in the number of different biotypes of Enterobacteriaceae per faecal sample. The numbers of biotypes ranged from 1–15 per faecal sample, the mean number of biotypes varied between 2·6 and 7·3 different biotypes per faecal sample per healthy volunteer. Inter-individual variations of five biotypes in the mean number of biotypes per faecal sample are normal. We assessed the minimal number of faecal samples that should be taken for comprehensive biotyping so as to determine reliably the mean number of different biotypes representative for the Colonization Resistance of an individual. It was found that a minimum of four faecal samples was required.
Faecal contamination of water and fingertip-rinses as a method for evaluating the effect of low-cost water supply and sanitation activities on faeco-oral disease transmission. II. A hygiene intervention study in rural north-east Thailand
Authors: Pinfold J. V.
Published: May 2009

An intervention study was developed from risk-factors associated with faecooral transmission, based on the levels of contamination in stored water and fingertip-rinses from households in rural north-east Thailand. This was designed to improve: (a) handwashing, particularly before cooking/eating and after defecation; (b) washing dishes immediately after use. Verbal messages were administered to two intervention groups, one also received a plastic container with a tap to assist these activities. Indicators of compliance were the direct observation of soaking dishes and the presence of faecal streptococci from fingertip-rinses; the main outcome indicator was Escherichia coli contamination of stored water. The intervention group receiving the container was significantly better than the control for indicators of compliance (P < 0·001 and P < 0·01) and its stored water was significantly less contaminated (P < 0·001). There was no significant improvement to the other intervention group, although some features of the intervention had clearly been made available to the control group. Humidity was significantly correlated with fingertip contamination (r = 0·2; P < 0·001) and with the peak of reported diarrhoea around the beginning of the rainy season.
Crystal violet reactions of fresh clinical isolates ofStaphylococcus aureusfrom two British hospitals
Authors: Freeman R. , Hudson S. J. , Burdess D.
Published: May 2009

When 168 fresh clinical isolates ofStaphylococcus aureuswere examined for their reactions on a medium containing 1 part in 100 000 crystal violet 50·6% of strains produced a purple appearance, 39·3% produced a white appearance and 10·1% produced a yellow appearance. Purple-reacting isolates were significantly associated with both invasive infections (P < 0·01) and hospital origin (P < 0·001). There were no significant associations between the crystal violet reactions and either animal contact or other properties previously reported to be characteristic of white and yellow-reacting strains (beta haemolysin and bovine coagulase production). The results of phage typing showed associations between susceptibility to group III phages and purple-reacting strains and between phage group II susceptibility and white and yellow-reacting strains. There was also a highly significant association between white reactions on crystal violet agar and susceptibility to lysis by a combination of all three groups (that is, I + II + III) and white-reacting strains were significantly more susceptible to lysis by phages 94 and/or 96, whether as a restricted pattern or as part of a broader pattern. The purple reaction on crystal violet medium may be a reliable marker of the ‘ hospital Staphylococcus’.
Further observations on enhancement of the infectivity of Fusobacterium necrophorum by other bacteria
Authors: Smith G. R. , Barton S. A. , Wallace L. M.
Published: May 2009

It had already been shown with a single virulent strain (A42) of Fusobacterium necrophorum that suspension of the fusobacteria in sub-lethal doses of broth cultures of other bacteria reduced the minimum infective dose (> 106 organisms) for mice by subcutaneous inoculation, sometimes to < 10 organisms. The present study extended the known range of bacteria with strong infectivity-enhancing properties to include Bacillus cereus, Klebsiella oxytoca and Staphylococcus aureus; and of those with weaker effect to include Bacillus subtilis, ‘Bacteroides melaninogenicus’, Clostridium sporogenes, Pasteurella haemolytica, and Proteus mirabilis.

The study also showed that five further virulent strains of F. necrophorum closely resembled A42 in respect of striking susceptibility to infectivity enhancement by Escherichia coli, Actinomyces (Corynebacterium) pyogenes and S. aureus. One further strain (A6) of F. necrophorum resembled A42 in respect of strong infectivity enhancement by A. pyogenes, S. aureus, B. cereus and K. oxytoca but differed from it and the other five strains in being only slightly affected by E. coli.

This work was a necessary prelude to the development of a method, based on infectivity enhancement, for the detection and isolation of F. necrophorum present in small numbers in heavily contaminated material such as faeces.
Viraemic transmission of Crimean-Congo haemorrhagic fever virus to ticks
Authors: Shepherd A. J. , Swanepoel R. , Shepherd S. P. , Leman P. A. , Mathee O.
Published: May 2009

In order to determine the way in which vertebrates infected with Crimean-Congo haemorrhagic fever (CCHF) virus and potential ixodid tick vectors interact in nature, immature and adult ticks of several species were fed on viraemic mammals and then assayed for virus content at varying times after feeding. CCHF virus was not isolated from ticks of six species tested after feeding as adults and immature forms on sheep with viraemia of 102·5−3·2LD 50/ml, nor from larval ticks fed on guinea-pigs and white-tailed rats with viraemia of 101·9−2·7LD 50/ml. In contrast, virus was isolated from 10 of 152 pools of engorged adult ticks of 5 species that fed on cattle with viraemia of 101·5−2·7LD 50/ml and from 3 of 137 female ticks after oviposition. Infection was transmitted to larval and nymphalHyalomma truncatumandH. marginatum rufipes, but not toRhipicephalus evertsi evertsi, from a scrub hare with viraemia of 104·250/ml but only nymphalH. truncatumandH. m. rufipesbecame infected from scrub hares with viraemia of 102·6−2·7LD 50/ml. Infection was transmitted trans-stadially inH. m. rufipesandH. truncatuminfected as nymphae, and adultH. m. rufipestransmitted infection to a sheep. No evidence of transovarial transmission was found in larval progeny of ticks exposed to CCHF virus as adults on sheep and cattle or as immatures on scrub hares.
Rubella in the developing world
Authors: Miller C. L.
Published: May 2009

Before Gregg's historic observation [1] rubella was not considered to have clinical or epidemiological importance in any country. In the western world epidemics occurred at varying intervals but with little morbidity and apparently only minor complications. Despite confirmation of Gregg's findings from many quarters, it was not until the worldwide outbreaks in the 1960s that the aftermath of rubella infection in pregnancy was fully realized. As a result of the 1964 outbreak in New York City, more than 1000 children were born with congenital rubella syndrome (CRS) and over 300 pregnancies either aborted spontaneously or were terminated for rubella infection [2]. The number of children affected represented 1% of births in the city; if extrapolated to the whole country this gave an estimated total of 30000 cases of CRS. No such disasters have so far been reported from the developing world.
Mannose-resistant adhesion of motileAeromonasto INT407 cells and the differences among isolates from humans, food and water
Authors: Nishikawa Y. , Kimura T. , Kishi T.
Published: May 2009

Aeromonashas been recognized as an important enteropathogen, but factors related to its virulence have not been clarified. For most enteric pathogens, attachment is a prerequisite for infection and for the effective delivery of toxins to the intestinal epithelial cells. We examined a total of 273 strains isolated from stool, food and environmental specimens by an assay for mannose-resistant adhesion to INT407 cellsin vitro. Seventeen of the 102 faecal isolates were adhesive strains with more than 10 bacteria adhering per cell, while only 2 of the 118 isolates from foods and river water adhered to the cells (P < 0·001). It is possible that the adhesion might serve as a marker for discrimination between the pathogenic and nonpathogenic isolates. The 8 highly adhesive strains with more than 20 adhering organisms per cell were scrutinized for the mechanism of adhesion. No correlation was apparent between the adhesion to INT407 cells and hydrophobicity. It was noted that fucose inhibited the adhesion of four strains as well as haemagglutination by them. Electronmicroscopic studies showed the presence of flexible and curvilinear fimbriae in only 2 of the 8 highly adhesive strains.
Ten and a half years seroepidemiology ofMycoplasma pneumoniaeinfection in Denmark
Authors: Lind K. , Bentzon M. W.
Published: May 2009

The study was based on a computerized card index of 9161 patients who had at least one positive blood specimen in theMycoplasma pneumoniaecomplement fixation test. A total of 12562 specimens from these patients had been sent to Statens Seruminstitut from hospitals and general practitioners during a 10·5-year period. The period encompassed a previously described endemic period in a 30-year study of the epidemiological pattern ofM. pneumoniaeinfection in Denmark [1], The serological data presented support the hypothesis advanced here that a more than sixfold increase of children in day care might have contributed to a change in the epidemiological pattern. The correlation between age and level of specific antibodies, as well as persistence of seropositivity, were also investigated.
Genetic diversity among toxigenic and nontoxigenicVibrio choleraeO1 isolated from the Western Hemisphere
Authors: Chen F. , Evins G. M. , Cook W. L. , Almeida R. , Hargrett-Bean N. , Wachsmuth K.
Published: May 2009

Multilocus enzyme electrophoresis was used to examine genetic relationships among and between toxigenic and non-toxigenic isolates ofVibrio choleraeO1 obtained from patients and the environment in the US Gulf Coast and surrounding areas. A total of 23 toxigenic and 23 non-toxigenic strains were examined. All the toxigenic and 7 of the non-toxigenic strains had the same alleles at 16 enzyme loci, whereas the balance of the nontoxigenic strains had 9 distinct combinations of alleles. This study suggests that all of the toxigenic strains belong to a single clone, and that while some of the non-toxigenic isolates were related, most were of diverse origin.
Relationship between cytomegalovirus and colonization of the oropharynx by Gram-negative bacilli following renal transplantation
Authors: Mackowiak P. A. , Goggans M. , Torres W. , Dal Nogare A. , Luby J. P. , Helderman H.
Published: May 2009

Numerous investigators have reported an increased incidence of pneumonia caused by Gram-negative bacilli and other secondary pathogens in transplant recipients infected by cytomegalovirus (CMV). To determine if CMV infections are related to colonization of the upper respiratory tract by Gram-negative bacilli, we examined prospectively 22 renal transplant recipients with sequential bacteriological, virological and biochemical examinations performed just prior to and at various times after transplantation. Only 11% of subjects had Gram-negative bacilli isolated from gargle specimens prior to transplantation, as compared to 54% after transplantation. More importantly, after transplantation, subjects with active CMV infections were more likely to have prolonged oropharyngeal carriage of Gram-negative bacilli than subjects without CMV infections (36%v.. 25%). During active CMV infections, the rate at which Gram-negative bacilli were isolated from gargle specimens rose from 28 to 47%. During culture-positive CMV infections, the isolation rate reached 57% and was significantly different from that of CMV-negative samples (P< 0·01). The increased rate of Gram-negative bacillary isolation from gargle specimens during CMV infections was not a function of type of immunosuppresive agents used, rejection episodes, antibiotic administration, concomitant hepatitis B, Epstein–Barr (EBV) virus, or herpes simplex virus infections, or alterations in salivary fibronectin concentrations.
The epidemiology of salmonella in calves: the role of markets and vehicles
Authors: Wray C. , Todd N. , McLaren I. M. , Beedell Y. E.
Published: May 2009

Environmental contamination has been shown to be an important aspect of the epidemiology of salmonellosis in calves. Markets and transport vehicles are important links in the calf marketing chain and these were investigated to determine the level of salmonella contamination.

Salmonellas were isolated from 7 of the 14 markets surveyed, with 31 of 838 samples (3.7%) being positive. Nine different salmonella serotypes, of which the commonest wasSalmonella typhimurium, were isolated. Four different phage types ofS. typhimuriumwere detected, the commonest being DT204C.

Salmonellas were isolated from 22 of the 107 vehicles (20.6%) examined before washing and from 4 of the 62 vehicles (6.5%) examined after cleaning. Twelve different salmonella serotypes were isolated, of which the most frequent wasS. typhimurium. The commonest of the six differentS. typhimuriumphage types was DT204C.

These results indicate that improved cleaning and disinfection routines both for vehicles and markets are necessary to control salmonellosis in calves.
The serological relationship betweenEscherichia coliO157 andYersinia enterocoliticaO9 using sera from patients with brucellosis
Authors: Chart H , Okubadejo O. A , Rowe B
Published: May 2009

Sera from ten patients with positive brucella serology were used to investigate antibody cross-reactions between the O-antigens ofEscherichia coli0157 andYersinia enterocolitica09. SDS-PAGE profiles of lipopolysaccharide (LPS), purified from strains ofE. coli0157 andY. enterocolitica09, were reacted with sera by immunoblotting. All ten sera contained antibodies which bound to the LPS ofE. coli0157, and five of these sera also contained antibodies which bound to the LPS ofY. enterocolitica09. Absorption studies using these five cross–reacting sera indicated the existence of at least three epitopes exposed on the O–antigens ofE. coli0157 andY. enterocolitica09. One antigen binding site appeared to be exposed on the LPS of both organisms, while one epitope was exposed on the LPS of E. coli 0157 only, and another on the LPS ofY. enterocolitica09 only.