bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrophoretic characterisation of the outer membrane proteins ofYersinia pestisisolated in north-east Brazil
Authors: Abath F. G. C. , Almeida A. M. P. , Ferreira L. C. S.
Published: May 2009

The outer membrane proteins of 38Yersinia pestisisolates from all known plague foci of north-east Brazil were analysed by SDS-PAGE. Approximately 20 bands were consistently found in all strains analysed and 11 were selected for comparative studies. Although qualitative differences among the electrophoretic profiles of outer membrane proteins of wildY. pestisisolates were not observed, quantitative alterations were clearly noted for most of these proteins. No particular quantitative alteration of the electrophoretic profile of outer membrane proteins could be associated with the period of isolation and geographic origin of the isolates. The 64 kDa outer membrane protein was significantly expressed in higher amounts amongY. pestisstrains isolated from a recent plague outbreak. The possible use of electrophoretic profiles of outer membrane proteins of wildY. pestisisolates as a tool for epidemiological studies and for the analysis of virulence determinants is discussed.
The source ofYersiniaspp. in pasteurized milk: an investigation at a dairy
Authors: Greenwood M. H. , Hooper W. L. , Rodhouse J. C.
Published: May 2009

Pasteurized bottled milk supplied by a single dairy was frequently found to be contaminated withYersiniaspp. Investigations were carried out at the dairy in an effort to pinpoint the source of these organisms. Viable counts obtained from milk bottle rinses indicated that bottle washing was often unsatisfactory, and on one occasionY. frederikseniiwas isolated from the pooled rinse water of six bottles. Samples of milk were taken on arrival at the dairy and at various stages following pasteurization. Heat resistance tests carried out on strains of yersinia isolated from pasteurized milk indicated that they would not survive the pasteurization process. However two strains of yersinia were isolated from a sample of milk taken immediately after pasteurization but before bottling. The thermograph indicated that the time/temperature conditions applied during pasteurization were adequate. The presence of yersinia strains in the milk at this stage therefore suggests that undetectable levels of raw milk were being allowed to contaminate the pasteurized milk. The absence of yersinia in cartoned samples produced on the same day as contaminated bottled samples indicated that environmental contamination of the bottle filler valve also may have occurred at times. Results of this investigation indicate that increased vigilance is required to ensure proper operation of pasteurizers and bottle washers.
Application of a new phagetyping scheme to campylobacters isolated during outbreaks
Authors: Salama S. M. , Bolton F. J. , Hutchinson D. N.
Published: May 2009

A new scheme for phagetyping campylobacters has been evaluated using strains isolated from five outbreaks. The phagetyping results have been compared with the results of Penner serotyping, Lior serotyping and Preston biotyping. Phagetyping recognized the causative strains in all of the incidents and also differentiated these strains from animal and environmental strains isolated during these investigations. In some outbreaks phagetyping proved to be more discriminatory than serotyping or biotyping, e.g. strains of Penner serotype 2, and serogroup 4, 13, 16, 50 were subdivided by this method. Phagetyping is to be recommended for typing strains from outbreaks and although the results indicate that it may be used alone we advocate that it should be used in conjunction with one of the established typing methods.
A study of human respiratory tract chlamydial infections in Cambridgeshire 1986–88
Authors: Wreghitt T. G , Barker C. E , Treharne J. D , Phipps J. M , Robinson V , Buttery R. B
Published: May 2009

Human respiratory tract chlamydial infections have been studied in Cambridge-shire for many years, but until recently we have been unable to distinguish between infection withChlamydia psittaciOrChlamydia pneumoniae(TWAR). In this study, we have employed the micro-immunofluorescence (micro-IF) test for this purpose and to look for the relative incidence ofC. psittaciandC. pneumoniaeinfections in Cambridgeshire. Among 50 patients with community-acquired respiratory tract symptoms whose serum samples had Chlamydia complement fixation test titres ≥ 64, 25 had evidence of recentC. psittaciorC. pneumoniaeinfection. Nineteen (76%) of the 25 patients had evidence of recentC. psittaciinfection and of these 16 (84%) had recently had contact with birds. Six patients (24%) had evidence of recentC. pneumoniaeinfection, and of these, only two (33% had recently had contact with birds). WhileC. psittaciwas grown from several of the birds associated with humanC. psittaciinfection, it was not cultured from any of the birds in contact with the two humanC. pnemoniaecases.
The avidity of specific IgM detected in primary rubella and reinfection
Authors: Thomas H. I. J. , Morgan-Capner P.
Published: May 2009

An IgM capture enzyme-linked immunosorbent assay for rubella-specific IgM was used to assess the avidity of specific IgM by comparing the results obtained with and without a mild protein denaturant in the washing fluid used after incubation of IgM with rubella haemagglutinating antigen. An avidity index (AI) was calculated with AIs < 50% considered to indicate low avidity. Sera from recent primary rubella, rubella reinfection and from patients persistently reactive for specific IgM were tested. Urea and diethylamine (DEA) were compared as the protein denaturants. Twenty-six of 28 sera from cases of primary rubella gave an AI < 50% with DEA, compared with 25 of 28 with urea. Seventeen of 20 sera from cases of reinfection gave an AI > 50% with DEA whereas only 14 of 20 had a similarly high avidity with urea. Eight of 10 sera from 4 cases of persistent specific IgM reactivity gave AIs > 50% with DEA, although this was reduced to 5 when urea was used. Thus a difference has been demonstrated between the avidity of specific IgM in primary infection from that demonstrated after a secondary antigenic challenge (reinfection). This may help in serologically distinguishing primary infection from reinfection.
Plasmid profile analysis and antimicrobial susceptibility patterns of shigella isolates from Nigeria
Authors: Olukoya D. K. , Oni O.
Published: May 2009

In an epidemiological survey, plasmid profiles and antimicrobial susceptibility testing of 100 shigella isolates in Lagos, Nigeria was done. All the isolates were sensitive to nalidixic acid, nitrofurantoin and ciprofloxacin. The commonest antimicrobial susceptibility pattern was resistance to ampicillin, colistin sulphate, co-trimoxazole, streptomycin and tetracycline. All but 4 of 100 isolates screened contained one or more plasmids. Plasmid profile analysis distinguished more strains than did antimicrobial susceptibility patterns. A total of 36 isolates was able to transfer resistance plasmids toEscherichia coliK-12 by conjugation. Usingin vitrotransformation, seven isolates transferred resistance. These plasmids specified resistance to tetracycline, streptomycin, sulphonamide, trimethoprim and ampicillin.
Numerical analysis of SDS–PAGE protein patterns ofSerratia marcescens: a comparison with other typing methods
Authors: Holmes B. , Costas M. , Sloss L. L.
Published: May 2009

Twenty-five cultures comprising 18 clinical isolates ofSerratia marcescensfrom two hospitals, the type strain ofS. marcescens, two reference strains ofS. marinorubra, the type or a reference strain of three other Serratia species and a reference strain of undetermined species, 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 of a numerical analysis which divided the clinical isolates into eight protein types. Comparison with O-serotyping indicated that the level of discrimination by SDS–PAGE was similar. As with O-serotyping, a secondary scheme, such as phage typing, is necessary to differentiate strains of the same protein type. We conclude that high-resolution SDS–PAGE of proteins provides an effective adjunct to other methods for typing isolates ofS. marcescens.
Health effects of beach water pollution in Hong Kong
Authors: Cheung W. H. S. , Chang K. C. K. , Hung R. P. S. , Kleevens J. W. L.
Published: May 2009

Prospective epidemiological studies of beach water pollution were conducted in Hong Kong in the summers of 1986 and 1987. For the main study in 1987, a total of 18741 usable responses were obtained from beachgoers on nine beaches at weekends. The study indicated the overall perceived symptom rates for gastrointestinal, ear, eye, skin, respiratory, fever and total illness were significantly higher for swimmers than non-swimmers; and the swimming-associated symptom rates for gastrointestinal, skin, respiratory and total illness were higher at ‘barely acceptable’ beaches than at ‘relatively unpolluted’ ones.Escherichia coliwas found to be the best indicator of the health effects associated with swimming in the beaches of Hong Kong. It showed the highest correlation with combined swimming-associated gastroenteritis and skin symptom rates when compared with other microbial indicators. A linear relationship betweenE. coliand the combined symptom rates was established. Staphylococci were correlated with ear, respiratory and total illness, but could not be used for predicting swimming-associated health risks. They should be used to complementE. coli. The setting of health-related bathing-water quality standards based on such a study is discussed.
Serological study of the epidemiology of mumps virus infection in north-west England
Authors: Nokes D. J. , Wright J. , Morgan-Capner P. , Anderson R. M.
Published: May 2009

Serum samples from individuals of a wide age range, collected in northwest England in 1984 and 1986, provide the basis for an analysis of the epidemiology of mumps virus infection. A radial haemolysis test yielding quantitative antibody measurements was used to screen samples for mumps-specific IgG. Analyses of resultant age-seroprevalence profiles, using statistical models, revealed an age-related pattern in the rate of infection per susceptible similar to that observed for other childhood infections. This rate, or force of infection, was low in young children, high in older children, and low in adults. In addition, the serological surveys provide evidence for time-dependent changes (both epidemic and longer-term) in the rate of mumps virus transmission. The longer-term changes, reflected in the pattern of the age-acquisition of specific antibodies, are supported by evidence from case notification data. The implications of temporal changes in incidence to the interpretation and design of serological surveys are considered.
Similarities in nucleotide sequence between serum and faecal human parvovirus DNA
Authors: Turton J. , Appleton H. , Clewley J. P.
Published: May 2009

Two DNA clones were obtained from faecal specimens containing a parvovirus-like small round virus from a 1977 outbreak of gastroenteritis, and their nucleotide sequences were determined and found to be essentially identical with parts of the published sequence of serum parvovirus B19 and with a B19 isolate (JB) partially sequenced in this study. The clones corresponded mainly to genome regions coding for non-structural proteins, but also include a sequence of some 160 bp coding for structural proteins. Southern blotting experiments with a full-length B19 probe revealed a virion-sized 5·5 kbp DNA band in specimens from gastroenteritis cases in both 1977 and 1986. Thus the nucleotide sequence and hybridization results suggest that the virus seen in these studies is very similar to B19. Further work is necessary to clarify the antigenic relationship of these viruses.
Characterization of the antibody response inCorynebacterium jeikeiumsepticaemias
Authors: Clark I. , Burnie J. P. , Coke A. P. , Matthews R. C. , Oppenheim B. A.
Published: May 2009

Corynebacterium jeikeiumcauses septicaemia in neutropenic patients usually after colonizing intravenous lines. This paper reports the results of immunoblotting sera from 14 patients with aC. jeikeiumsepticaemia. Recovery from the septicaemia was associated with production of both IgM and IgG against antigenic bands of 50, 52 and 110 kDa. Antibody against the 110 kDa band was present in controls but the antibody against the 50 and 52 kDa was specific to those patients who had on-going or previousC. jeikeiuminfection. A case ofC. jeikeiumendocarditis is also presented and here recovery was associated with seroconversion to the 50 and 52 kDa bands.
Q fever in Plymouth, 1972–88: A review with particular reference to neurological manifestations
Authors: Reilly S. , Northwood J. L. , Caul E. O.
Published: May 2009

Between 1972 and 1988 we have serologically confirmed 103Coxiella burnetiiinfections: 46 were acute, 5 were chronic, 52 represented past infections. Details of 61 cases are presented.

Of acute cases 80 % had respiratory involvement; at least 63 % had pneumonias. The incidence (22%) of neurological complications was of particular interest; 40% of these patients had prolonged sequelae. One acutely ill patient died of fulminating hepatitis. Patients with pre-existing pathology or immunosuppression were especially susceptible toC. burnetii.

In the absence of acute sera, the complement fixation test alone provided inadequate differentiation between recent and past Q fever: phase II titres persisted at ⋝ 80 for more than 1 year after the acute infection in 15 cases; maximum duration of persistence was 14 years. Three patients acquired high phase I titres.

Only 5% of cases had chronic Q fever, but in view of the diverse sequelae observed in this series, we suggest that long-term serological and clinical follow-up of all cases of Q fever is fully justified.
Further studies on bluetongue and bluetongue-related Orbiviruses in the Sudan
Authors: Mohammed M. E. H. , Mellor P. S.
Published: May 2009

The seasonal incidence of bluetongue virus (BTV) in Central Sudan is related primarily to fluctuations in the prevalence of the vector, Culicoides imicola. Population densities of this midge begin to rise with the onset of precipitation and peak during October, before falling sharply at the end of the rainy season in November. These are also the months of BTV transmission. Populations of C. schultzei, the commonest midge in Central Sudan, are also related to the rainy season but this species does not seem to be involved with BTV transmission.

BTV serotype 2 was isolated from C. imicola confirming the status of this midge as a known vector but a second isolate of the same serotype was made from a mixed pool of Culicoides not including C. imicola. This suggests that BTV transmission in the Sudan may involve more than one species of Culicoides. Epizootic haemorrhagic disease virus (EHDV) serotype 4 and a palyam virus were isolated from C. schultzei which indicates that this species may be involved in the transmission of BT-related viruses. Seven further virus isolates from sentinel calves at Shambat (Khartoum) confirmed the presence of BTV serotypes 1, 4 and 16, and an untyped EHDV (designated 318) in the Sudan. All of the viruses isolated and identified during the course of this work are recorded from the Sudan for the first time.
Insights into neutralization of animal viruses gained from study of influenza virus
Authors: Outlaw M. C. , Dimmock N. J.
Published: May 2009

It has long been known that the binding of antibodies to viruses can result in a loss of infectivity, or neutralization, but little is understood of the mechanism or mechanisms of this process. This is probably because neutralization is a multifactorial phenomenon depending upon the nature of the virus itself, the particular antigenic site involved, the isotype of immunoglobulin and the ratio of virus to immunoglobulin (see below). Thus not only is it likely that neutralization of one virus will differ from another but that changing the circumstances of neutralization can change the mechanism itself. To give coherence to the topic we are concentrating this review on one virus, influenza type A which is itself well studied and reasonably well understood [1–3]. Reviews of the older literature can be found in references 4 to 7.
A sentinel network of microbiological laboratories as a tool for surveillance of infectious diseases in Belgium
Authors: Walckiers D. , Stroobant A. , Yourassowsky E. , Lion J. , Cornelis R.
Published: May 2009

In the development of a surveillance programme for infectious diseases in Belgium, a national network of microbiological laboratories has been responsible, since February 1983, for the weekly registration of certain pathogenic agents. Thus, the main epidemiological features of a selected number of infections in Belgium can be characterized.
A sensitive method for isolating Fusobacterium necrophorum from faeces
Authors: Smith G. R. , Barton S. A. , Wallace L. M.
Published: May 2009

The isolation of Fusobacterium necrophorum present in small numbers in heavily contaminated material such as faeces or soil is hampered by the lack of an efficient selective medium and by the high minimum infective dose of the organism. A sensitive method for the detection and isolation of faecal strains of F. necrophorum type A was based on the subcutaneous injection of faeces, suspended (5% w/v) in broth culture of Actinomyces (Corynebacterium) pyogenes or Staphylococcus aureus to increase fusobacterial infectivity, into mice pretreated with clostridial antitoxins. When necrobacillosis developed F. necrophorum was identified microscopically in tissue from the advancing edge of the lesion and isolated on a partly selective medium.

The enhancement of fusobacterial infectivity produced by A. pyogenes and by S. aureus was high, but the latter was slightly the more efficient, enabling as few as 80 F. necrophorum organisms/g of faeces to be detected.

Use of the method showed that 3 of 16 wallabies had F. necrophorum in their faeces at the time of examination. Numerous epidemiological applications are suggested.
An assessment of cleaning and sampling methods for food-contact surfaces in premises preparing and selling high-risk foods
Authors: Tebbutt G. M.
Published: May 2009

The performance of agar-contact plates and an alginate-swab method for sampling food surfaces before and after cleaning was compared. Contact plates were more convenient, and were at least as sensitive as the swabbing method. To assess cleaning efficiency repeated sampling was carried out in selected premises, and several cleaning methods were introduced for trial periods. Some surfaces, notably wood and polypropylene, were particularly difficult to clean. For these scrubbing with a nylon brush was the best method. Other surfaces were more easily cleaned, and generally the methods introduced as part of this study were better than the original method used in the premises. Paper proved to be unpopular, and cleaning solutions applied with it did no better than those cleaned with a multiuse cloth kept soaking in a detergent and hypochlorite solution.
Rubella in Europe
Authors: Galazka A.
Published: May 2009

Postnatal rubella is a mild illness, a disease which was considered to be of only minor importance for many years. The first authors to write about the disease as distinct from other exanthemata were German physicians; they differentiated rubella from measles and scarlet fever in the latter part of the eighteenth century and called the disease Rotheln. Hence the common English language eponym is ‘German measles’. Some consider that the term ‘German’ in German measles is probably of literary rather than of geographical significance and that it came from the old French ‘germain’ (derived from the Latin ‘germanus‘), meaning ‘closely akin to’ measles [1]. That it is not generally called by its German name, Rotheln, is due to Veale, a Scottish physician who in 1866 described 30 cases of rubella in the Edinburgh Medical Journal, and proposed ‘rubella’ as a short and euphonius name that could be easily pronounced [2].
Phage typing of Staphylococcus saprophyticus
Authors: Pereira A. Torres , Cristino J. A. G. Melo
Published: May 2009

This study included 502 staphylococcus strains;Staphylococcus saprophyticus(297 strains)S. cohnii(47),S. xylosus(10),S. epidermidis(67) andS. aureus(81). Mitomycin C induction was performed on 100 isolates ofS. saprophyticusand all induced strains were reacted with each other. Twenty-six strains proved to be lysogenic. Phages were propagated and titrated. With 12 of the phages there were three frequent associations, named lytic groups A, B and C, which included 75% of all typable strains. Typability of the system was 45% and reproducibility was between 94.2% and 100%. Phages did not lyseS. aureusandS. epidermidisstrains, but they lysedS. saprophyticusand only rare strains of other novobiocin resistant species. EffectiveS. saprophyticustyping serves ecological purposes and tracing the origin of urinary strains from the skin or mucous membranes. Phage typing in association with plasmid profiling previously described, are anticipated as complementary methods with strong discriminatory power for differentiating amongS. saprophyticusstrains.
Characterization of a protective protein antigen ofErysipelothrix rhusiopathiae
Authors: Groschup M. H. , Cussler K. , Weiss R. , Timoney J. F.
Published: May 2009

Although vaccination is widely practiced against infection byErysipelothrix rhusiopathiaein pigs and turkeys, the protective antigen(s) involved have not been fully characterized or purified to homogeneity. Antigens of E.rhusiopathiaestrain T28, serotype 2b, and of FRANKFURT XI, serotype N, in culture supernatant and in extracts made with hot acid, 10 mM NaOH, ultrasound or EDTA were compared by SDS-PAGE and immunoblotting and in a mouse protection test. EDTA and 10 mM NaOH yielded highly protective extracts; culture supernatant was less protective and ultrasonic or hot acid extracts stimulated little or no protection in mice. Protective antisera from swine, horses and mice recognized prominent bands of molecular mass (m.m.) of 66–64 and 40–39 kDa in EDTA and 10 mM NaOH extracts. Mice immunized with preparations of the 66–64 kDa band purified by preparative electrophoresis were protected. Both antigens were trypsin sensitive, contained no detectable polysaccharide, and showed a marked tendency to aggregate in the absence of SDS.
A serologically confirmed, case-control study, of a large outbreak of hepatitis a in China, associated with consumption of clams
Authors: Tang Y. W. , Wang J. X. , Xu Z. Y. , Guo Y. F. , Qian W. H. , Xu J. X.
Published: May 2009

A matched and serologically confirmed case-control study was carried out to investigate the source of an outbreak of acute hepatitis involving 290000 cases in the suburbs of Shanghai, in January 1988. A total of 132 patients with acute hepatitis from six different hospitals were chosen as cases and the same number of control patients without hepatitis were matched for gender, age, admission date and area of residence. Serum specimens from both case and control patients were detected for specific anti-hepatitis A (HA) IgM antibody and a questionnaire was used to investigate probable risk factors related to the outbreak. The positive rate of anti-HA IgM was 98·48% in the case group and only 0·76% in the control, indicating that the infection was caused by HA virus. The results revealed that the source and mode of transmission were due to the consumption of contaminated and inadequately cooked clams (Anadara subcrenata lischke). There was a highly positive dose-response relationship between the odds ratio of contracting HA and the quantity or frequency of clam consumption. The odds ratios of acquiring HA from clams were up to 62·4–63·4 by both group stratification and multiple unconditional logistic regression analyses.
Gastrointestinal carriage ofClostridium difficilein cats and dogs attending veterinary clinics
Authors: Riley T. V. , Adams J. E. , O'Neill G. L. , Bowman R. A.
Published: May 2009

Cats and dogs being treated at two veterinary clinics were investigated for gastrointestinal carriage ofClostridium difficileusing selective solid and en-richment media. Thirty-two (39.5%) of 81 stool samples yieldedC. difficile. There were significant differences in isolation rates between clinics, 61.0% of animals being positive at one clinic compared to 17.5% at the other (Chi-square, P < 0.005). Of 29 animals receiving antibiotics, 15 (52.0%) harbouredC. difficilewhile 11 (23.9%) of 46 animals not receiving antibiotics were positive (Chi-square, P < 0.01). There was no difference in carriage rate between cats (38.1%) and dogs (40.0%). The environment at both veterinary clinics was surveyed for the presence ofC. difficile. Fifteen of 20 sites at one clinic were positive compared to 6 of 14 sites at the other clinic. Both cytotoxigenic and noncytotoxigenic isolates ofC. difficilewere recovered from animals and environmental sites. These findings suggest that household pets may be a potentially significant reservoir of infection withC. difficile.
Heterosexual and homosexual transmission of hepatitis C virus: relation with hepatitis B virus and human immunodeficiency virus type 1
Authors: Corona R. , Prignano G. , Mele A. , Gentili G. , Caprilli F. , Franco E. , Ferrigno L. , Giglio A. , Titti F. , Bruno C. , Verani P. , Pasquini P.
Published: May 2009

A seroprevalence study was carried out on 1757 outpatients consecutively seen in a sexually transmitted disease (STD) clinic in order to evaluate the sexual transmission of hepatitis C virus (HCV). A total of 1442 consenting patients were tested for hepatitis C, hepatitis B and human immunodeficiency virus type 1 (HCV. HBV, HIV - 1) antibodies. The relations between anti-HCV, anti-HBc and anti-HIV - 1 were studied. Of 73 anti-HCV positive reactions, 45 (61.6%) were confirmed by the recombinant immunoblot assay (RIBA). The proportion of individuals with anti-HCV was higher in outpatients with a history of sexually transmitted disease than without. It was 2.8% in non drug user heterosexuals and 2.9% in non drug user homosexuals. Intravenous drug users (IDU) had higher anti-HCV prevalence when a history of STD was taken into account (42.3% in subjects with STD versus 36.7% in subjects without STD). Among non drug user heterosexuals an association was found between anti-HCV and anti-HBc. These data suggest that sexual transmission of HCV occurs, although it seems to be less efficient than other parenteral modes of transmission. When a more sensitive and specific marker of HCV infection become available, a more accurate estimate of the frequency and efficiency of the sexual transmission will be possible.
Class-specific antibodies to bovine respiratory syncytial virus in experimentally infected lambs
Authors: Sharma R. , Woldehiwet Z.
Published: May 2009

Enzyme-linked immunoabsorbent assay (ELISA) was used to titrate virus-specific IgG, IgM and IgA levels in nasal secretions, lung lavage fluids and serum samples sequentially obtained from lambs experimentally infected with bovine respiratory syncytial virus (RSV). Virus-specific IgG and IgM responses were measured by the indirect double antibody sandwich ELISA using anti-bovine RSV monoclonal antibody, as capture antibody, and peroxidase-conjugated anti-sheep IgG and anti-sheep IgM. Virus-specific IgA antibodies were measured by antibody capture assay using anti-sheep IgA (α–chain specific) and anti-bovine RSV monoclonal antibodies.

Bovine RSV-specific IgM and IgA antibodies were detected in the serum samples within 6 days post-inoculation (p.i.). Virus-specific IgC antibodies appeared in serum samples 4 days later. In nasal secretions, IgA antibodies appeared 7 days p.i. but IgM antibodies were not detected until 12–16 days p.i. In serum samples, IgM titres were predominant for the first 2 weeks p.i. IgC titres becoming predominant thereafter. In nasal secretions and lung lavage fluids, IgA titres were significantly higher than IgM or IgG titres up to 21 days p.i. (0·01).
Methods for estimating the incidence of primary infection in pregnancy: a reappraisal of toxoplasmosis and cytomegalovirus data
Authors: Ades A. E.
Published: May 2009

Accurate incidence information is required to plan and evaluate screening programmes which have been proposed for the detection of primary toxoplasmosis and cytomegalovirus infection in pregnancy. Appropriate statistical methods are described for deriving incidence rates and their confidence intervals from three types of data: change in age-specific seroprevalence, seroconversion, and IgM studies. These methods are applied to seven published studies on toxoplasmosis and cytomegalovirus carried out in the UK. In these publications only one estimate of the infection rate per pregnancy was correctly derived, and none were accompanied by confidence intervals. Using the proposed methods, most estimates of the primary toxoplasmosis rate in these studies were between 2·5 and 5·5 per 1000 pregnancies, compared to the 2 per 1000 usually cited. Most cytomegalovirus incidence estimates were between 4 and 10 per 1000 pregnancies.
Estimation of the dynamics and rate of transmission of classical swine fever (hog cholera) in wild pigs
Authors: Hone J. , Pech R. , Yip P.
Published: May 2009

Infectious diseases establish in a population of wildlife hosts when the number of secondary infections is greater than or equal to one. To estimate whether establishment will occur requires extensive experience or a mathematical model of disease dynamics and estimates of the parameters of the disease model. The latter approach is explored here. Methods for estimating key model parameters, the transmission coefficient (β) and the basic reproductive rate (RDRS), are described using classical swine fever (hog cholera) in wild pigs as an example. The tentative results indicate that an acute infection of classical swine fever will establish in a small population of wild pigs. Data required for estimation of disease transmission rates are reviewed and sources of bias and alternative methods discussed. A comprehensive evaluation of the biases and efficiencies of the methods is needed.
The importance of P and type 1 fimbriae for the persistence ofEscherichia coliin the human gut
Authors: Tullus K. , Kühn I. , Ørskov I. , Ørskov F. , Möllby R.
Published: May 2009

The faecalEscherichia coliflora was studied in 89 infants. Each infant was followed with a mean of 12 faecal samples (range 5–21) between 0 and 18 months of age. All isolates were assayed for P fimbriae and biochemically phenotyped and the persistence of each strain (phenotype) in the infant's gut was determined. In a subset of strains the occurrence of type 1 fimbriae and adherence to HeLa cells was studied. Thirty-one per cent of isolates belonging to strains colonizing for longer than 6 months expressed P fimbriae compared to 19% of the isolates from strains colonizing 1–6 months or transient strains colonizing less than 1 month. Type 1 fimbriae and adherence to HeLa cells occurred similarly often in all groups of strains. We conclude that P fimbriae, but not type 1 fimbriae or HeLa cell adherence seemed to contribute to the ability of theE. colistrain to colonize the human intestine.
Seroepidemiology ofHelicobacter pyloriinfection in vegans and meat-eaters
Authors: Webberley M. J. , Webberley J. M. , Newell D. G. , Lowe P. , Melikian V.
Published: May 2009

An enzyme-linked immunosorbent assay has been used to diagnose serologically the prevalence ofHelicobacter pyloriinfection in Asian life-long vegans. There was no difference in the seropositivity between these individuals and a group of age-and sex-matched Asian meat-eaters, indicating the meat consumption is not a risk factor forH. pyloriinfection. However, both Asian groups had a higher prevalence of infection than age- and sex-matched Caucasian meat-eaters. Additionally, the Asian individuals had a wider range of specific IgG antibody concentrations than the Caucasians. This did not appear to be due to antigenic cross-reactivity betweenH. pyloriandCampylobacter jejuni. The significance of these observations to the establishment of cut-off levels for the serodiagnosis of certain ethnic groups is discussed.
Bancroftian filariasis in Pondicherry, South India – epidemiological impact of recovery of the vector population
Authors: Das P. K. , Manoharan A. , Subramanian S. , Ramaiah K. D. , Pani S. P. , Rajavel A. R. , Rajagopalan P. K.
Published: May 2009

An Integrated Vector Management (IVM) strategy was implemented from 1981 to 1985 in one part of Pondicherry, South India, for the control of the bancroftian filariasis vector Culex quinquefasciatus (the IVM area). The rest of the town (the comparison area) received the conventional larvicidal input. After 1985 both the areas were managed conventionally. The switch to conventional strategy resulted in an increase of vector density in both areas. The microfilaraemia prevalence in humans showed a general decline (P < 0·05) from 1986 to 1989 only in the IVM area whereas its intensity did not change significantly in either area. While the age-specific rate of gain of infection was generally unchanged in the IVM area, an increase in all age classes was observed after 1985 in the comparison area, where the Annual Transmission Index was high during the previous years. In both areas the rate of loss of infection increased during 1986–9 compared to 1981–6. The results suggest that 3 years is too short a period to relate the changes in entomological parameters to those in the microfilaraemia status of the population.
Streptococcal infection in general practice
Authors: Barnham M.
Published: May 2009

The last 30 years have been changes in emphasis in the study of streptococci and streptococcal diseases. Earlier work concentrated mainly on the sources and methods of cross-infection and descriptive epidemiology ofStreptococcus pyogenesin its major manifestations of respiratory, cutaneous and invasive infection and in the complications of rheumatic fever (RF), scarlet fever (SF) and post-streptococcal glomerulonephritis (PSGN).
Serological responses of chickens experimentally infected with Salmonella enteritidis PT4 by different routes
Authors: Chart H. , Baskerville A. , Humphrey T. J. , Rowe B.
Published: May 2009

Commercially reared chickens were challenged with Salmonella enteritidis phage-type (PT) 4 by aerosol, or via the conjunctiva. Inhalation of 2·9 × 102 or 4·2 × 103 S. enteritidis resulted in the production of IgG antibodies to the lipopolysaccharide (LPS) of S. enteritidis PT4. When the aerosol inoculum was increased to 2·4 × 105 bacteria per bird the antibody produced were predominantly of the IgM-class. Chickens challenged with 103S. enteritidis PT4 via the conjunctiva mounted only a poor immune response. Increasing the challenge dose to 108 S. enteritidis resulted in the production of high-titre serum antibodies of both the IgG and IgM classes. Results from this study suggest that aerosols containing small numbers of S. enteritidis PT4 might be responsible for intraflock infection of poultry.
Destruction of bacteria on fresh meat by hot water
Authors: Smith M. G.
Published: May 2009

Strains of different bacterial genera: Escherichia coli (7), Salmonella serotypes (7), Enteropathogenic E. coli O 157 (2), Aeromonas hydrophila (4), Yersinia enterocolytica (1), Pseudomonas fragi (5), and Listeria monocytogenes (5), inoculated onto the surface tissues of pieces of fresh beef were found to be susceptible to the lethal action of hot water. On average, more than 3 log10 (99·9%) of these organisms were destroyed when water at 80 °C was applied for 10 or 20 s. Therefore, a hot water decontamination cabinet would be effective for destroying in situ any viable cells of these bacteria which might be present on the surface tissues of fresh beef carcasses.
Laboratory diagnosis ofMycoplasma pneumoniaeinfection. 4. Antigen capture and PCR-gene amplification for detection of the mycoplasma: problems of clinical correlation
Authors: Williamson J. , Marmion B. P. , Worswick D. A. , Kok T. -W. , Tannock G. , Herd R. , Harris R. J.
Published: May 2009

Direct detection assays forMycoplasma pneumoniaewere established by PCR amplification of short sequences within the foot protein/adhesin (P1) gene and the 16S ribosomal RNA gene.

Specificity and sensitivity was excellent, no hybridization was observed withM. genitaliumand other humanMycoplasmaspecies. In nose and throat washings from subjects with respiratory infection a pattern of high counts (c.f.u./ml) ofM. pneumoniae(deduced from the amount of amplified PCR product), and a positive antigen capture assay, was found in 83% of subjects with serological evidence of current infection withM. pneumoniae.

A small proportion of subjects with serological patterns suggesting infection in the more distant past had positive PCR assays. This was considered to represent either persistence of the organism from a previous infection or perhaps transient carriage during a reinfection, without substantial change in antibody response.

PCR-based assay ofM. pneumoniaeoffers a powerful, rapid, and sensitive substitute for culture of the mycoplasma. Antigen capture, while less sensitive than PCR, offers the advantage that it is more often positive with samples from current infection and requires less stringent laboratory organization to contain false positive results. We conclude however that the laboratory diagnosis of a chosen clinical episode should not rest on the PCR or Ag-EIA assays alone, but must also include antibody assays to confirm whether infection is current or represents persistence from past exposure.
rRNA gene restriction patterns and biotypes ofShigella sonnei
Authors: Nastasi A. , Pignato S. , Mammina C. , Giammanco G.
Published: May 2009

Shigella sonneiis a major agent of diarrhoeal disease in developed as well as in developing countries. Several phenotypic methods to define strain differences have been applied to this species ofShigellaincluding, more recently, analysis of extrachromosomal and chromosomal DNA.

In this study, 432 endemic and epidemic strains isolated between 1975 and 1991 in Italy, France and Switzerland were submitted to rRNA gene restriction pattern analysis, after digestion of whole-cell DNA byHincII, and to concomitant biotyping.

Thirteen ribotypes, HI to H13, and five biotypes, a, d, e, f, g, were detected. Xinety-five percent of the sporadic strains were assigned to ribotypes HI to H4, which could be subtvped, except for H4, in different biotypes. Strains from each of seven different outbreaks had indistinguishable ribotype-biotype patterns. In contrast, 65 strains, isolated in Sicily in 1980 over an extended period of apparently epidemic increase of isolations and which had previously been considered to be a single bacterial clone on the basis of resistance pattern and phage type, were found to belong to two different and scarcely related ribotypes.

Ribotyping and biochemical subtyping appear to be a useful epidemiological tool in studies on the circulation and distribution of strains ofS. sonnei.
The carriage ofStreptococcus suistype 2 by pigs in Papua New Guinea
Authors: Paterson R. A. , Robertson I. D. , Sanders R. C. , Siba P. M. , Clegg A. , Hampson D. J.
Published: May 2009

An indirect fluorescent antibody test was used to detect the presence ofStreptococcus suistype 2 in nasal and pharyngeal swabs taken from pigs in Papua New Guinea. The rate of carriage for the two sites in domesticated indigenous village pigs was 0·5 and 2·5% respectively, compared to 39 and 43% for intensively reared pigs. These findings were supported by the results of a serological survey, using an enzyme linked immunosorbent assay, in which 87% of intensively reared pigs but only 8% of village pigs were seropositive toS. suistype 2.

It is proposed that in intensive piggeriesS. suistype 2 is continually cycled between pigs. In village pigs, the low population density and harsh environmental conditions prevents this cycle of infection.
The prevalence and genetics of resistance to commonly used antimicrobial agents in faecal Enterobacteriaceae from children in Bangladesh
Authors: Mamun K. Z. , Shears P. , Hart C. A.
Published: May 2009

The present study was undertaken to investigate the occurrence of antibiotic resistance in enteric flora in 64 children in rural Bangladesh over a 12-month period. The antibiotic resistance pattern of the isolates varied throughout the year and multiple resistance was highest during the post monsoon period. Seventythree percent of children had isolates resistant to more than three antibiotics throughout the year. Resistance to streptomycin was highest (78%), followed closely by ampicillin (72%). Of 82 multiply resistant isolates, plasmid DNA was demonstrated in 75%. Plasmid sizes ranged between 3·7 and 110 MDa, the commonest plasmids were of 70, 98 and 110 MDa. Complete or partial resistance was transferred by conjugation from 52% of the isolates, most frequently by single plasmids. The commonest plasmid incompatibility group was F11-A (46%) followed by incompatibility group P (22%). Plasmids of molecular weight 98 MDa most often hybridized with F11-A probes and those of 110 MDa with H11 probes. Plasmids from 10 transconjugants were digested with restriction enzymes and digest patterns demonstrated the presence of common plasmids. The findings show that there is a diverse, and mobile, genetic pool of resistance genes in this rural community. This genetic reservoir is potentially transferable to enteric pathogens, with major implications for public health and diarrhoeal disease control.
Factors enhancing adherence of toxigenicStaphylococcus aureusto epithelial cells and their possible role in sudden infant death syndrome
Authors: Saadi A. T. , Blackwell C. C. , Raza M. W. , James V. S. , Stewart J. , Elton R. A. , Weir D. M.
Published: May 2009

Toxigenic strains ofStaphylococcus aureushave been suggested to play a role in sudden infant death syndrome (SIDS). In this study we examined two factors that might enhance binding of toxigenic staphylococci to epithelial cells of infants in the age range in which cot deaths are prevalent: expression of the Lewisaantigen and infection with respiratory syncytial virus (RSV). By flow cytometry we demonstrated that binding of three toxigenic strains ofS. aureusto cells from non-secretors was significantly greater than to cells of secretors. Pre-treatment of epithelial cells with monoclonal anti-Lewisaor anti-type-1 precursor significantly reduced bacterial binding (P< 0·01); however, attachment of the bacteria correlated only with the amount of Lewisaantigen detected on the cells (P< 0·01). HEp-2 cells infected with RSV bound significantly more bacteria than uninfected cells. These findings are discussed in context of factors previously associated with SIDS (mother's smoking, bottle feeding and the prone sleeping position) and a hypothesis proposed to explain some cases of SIDS.
An epidemic of cholera due toVibrio choleraeO139 in Dhaka, Bangladesh: clinical and epidemiological features
Authors: Mahalanabis D. , Faruque A. S. G. , Albert M. J. , Salam M. A. , Hoque S. S.
Published: May 2009

We describe the disease spectrum and socio-demographic and epidemiological features of an epidemic of cholera due to a new pathogen.Vibrio choleraeO139, in patients attending a very large hospital in the metropolitan city of Dhaka, Bangladesh.

This hospital treats 70000–90000 patients a year with diarrhoeal diseases. A 4% systematic sample of 1854 patients attending from January to April 1993 were studied.

Five hundred and two (27%) of the 1854 patients were culture positive forV. choleraeO139 and 63 (3%) were culture positive forV. choleraeO1 biotype El Tor. Patients withV. choleraeO139 were mainly adults with a short history of watery diarrhoea. Eight-three percent of patients had moderate to severe dehydration. All recovered except one 80-year-old man with compromised renal function who died. Seventy-eight percent of patients required initial intravenous rehydration followed by oral rehydration therapy with rice ORS; they also received tetracycline to reduce diarrhoea severity. Most patients were from urban slums with inadequate sanitation facilities and hygiene practices.

The newly recognizedV. choleraeO139 infection produced an epidemic of severe dehydrating diarrhoea indistinguishable from clinical cholera in a population which experiences two epidemic peaks of cholera in a year due toV. choleraeO1. Infection with the latter does not appear to confer any cross-protection fromV. choleraeO139. The new pathogen suppressed, albeit temporarily,V. choleraeO1. Unlike other non-O1 serogroups ofV. choleraethis new serogroup appears to have epidemic potential.
Apramycin-resistantEscherichia coliisolated from pigs and a stockman
Authors: Hunter J. E. B. , Bennett M. , Hart C. A. , Shelley J. C. , Walton J. R.
Published: May 2009

Escherichia coliserotype O147:K89:K88a,c was found to be associated with outbreaks of diarrhoea in preweaner pigs of up to 4 weeks of age on a pig unit. Resistance to apramycin, gentamicin, netilmicin, tobramycin and other antibiotics was associated with conjugative plasmids of approximately 62 kb. The presence of a gene which encoded for the aminoglycoside acetyltransferase enzyme AAC(3)IV was confirmed by DNA hybridization.

Samples collected during the following 12 months revealed widespread dissemination of these resistance plasmids in non-serotypable, non-haemolyticE. colithroughout the farm. Apramycin-resistantE. coliwere also isolated from a stockman and it appeared from plasmid profile analysis and antibiotic sensitivity testing that the human isolates carried the same plasmid as that carried by the porcineE. coli.Klebsiella pneumoniae, with a slightly smaller conjugative plasmid and similar resistance pattern, was isolated from the stockman's wife.
Fatal nosocomial Legionnaires' disease: relevance of contamination of hospital water supply by temperature-dependent buoyancy-driven flow from spur pipes
Authors: Patterson W. J. , Seal D. V. , Curran E. , Sinclair T. M. , McLuckie J. C.
Published: May 2009

The investigation, epidemiology, and effectiveness of control procedures during an outbreak of Legionnaires' disease involving three immunosuppressed patients are described. The source of infection appeared to be a network of fire hydrant spurs connected directly to the incoming hospital mains water supply. Removal of these hydrants considerably reduced, but failed to eliminate, contamination of water storage facilities. As an emergency control procedure the incoming mains water was chlorinated continuously. Additional modifications to improve temperature regulation and reduce stagnation also failed to eliminate the legionellae.

A perspex test-rig was constructed to model the pre-existing hospital water supply and storage system. This showed that through the hydraulic mechanism known as ‘temperature buoyancy’, contaminated water could be efficiently and quickly exchanged between a stagnant spur pipe and its mains supply. Contamination of hospital storage tanks from such sources has not previously been considered a risk factor for Legionnaires' disease. We recommend that hospital water storage tanks are supplied by a dedicated mains pipe without spurs.