bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diversity and molecular variation among plasmids inSalmonella entericaserotype Dublin based on restriction enzyme fragmentation pattern analysis
Authors: Browning L. M. , Wray C. , Platt D. J. 
Published: May 2009

SummaryMolecular variation within and between plasmids ofSalmonella entericaserotype Dublin was analysed. Such variation has been demonstrated in the serotype-specific plasmids (SSP's) of Typhimurium and Enteritidis. The two aims of this study were to determine the plasmid diversity in a host-adapted serotype and also the incidence of molecular variation in the SSP among strains of Dublin using restriction endonuclease fragmentation pattern (REFP) analysis withPst1,Sma1 andEcoRV. Sixty-five strains were examined from seven countries. Plasmid profile and REFP analysis showed that none of the strains was plasmid-free. Seventy-seveń percent of the strains possessed the 72 kb SSP either alone or in combination with another plasmid; 23 % harboured plasmids which were molecular variants of the SSP. Four of the variants were more closely related to each other than to the reference SSP and were harboured by Dublin isolated from both the USA and Europe. A further three were shown to be cointegrate plasmids and were similarly distributed. Thirty-two percent of strains possessed the SSP alone. None of the UK strains was resistant to any of the antimicrobial agents tested whereas 74 % of the remaining strains were resistant to between one and five antimicrobial agents. This study corroborates previous findings concerning the high degree of stability of the SSP and confirmed the clonal nature of Dublin. Co-resident plasmids provided evidence of sub-clones within localized geographical areas.
Control of infection with multiple antibiotic resistant bacteria in a hospital renal unit: the value of plasmid characterization
Authors: Reed C. S. , Barrett S. P. , Threlfall E. J. , Cheasty T. 
Published: May 2009

SummaryAn outbreak of infections due to multiple antibiotic-resistant bacteria took place over a period of approximately 18 months in a renal unit. Strains ofEscherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Citrobacterspp. andPseudomonasspp. were involved, and a variety of antibiotic resistances was encountered. Closely related plasmids encoding resistance to aztreonam, ceftazidime and piperacillin, possibly derived from an archetypal plasmid of 105 kb were found in the majority of isolates examined. After limiting the use of aztreonam the incidence of new patient isolates of multiple-resistant organisms was greatly reduced. This study demonstrated how molecular studies can contribute to the control of an outbreak situation in a hospital unit by providing an impetus to reduce the use of specific antibiotics.
RAPD analysis of isolates ofBurkholderia pseudomalleifrom patients with recurrent melioidosis
Authors: Haase A. , Melder A. , Smith-Vaughan H. , Kemp D. , Currie B. 
Published: May 2009

SummaryTwenty-seven isolates ofBurholderia pseudomallei(formerlyPseudomonas pseudomallei) from ten patients with recurrent melioidosis were analysed by RAPD. In two cases RAPD patterns in recurrent isolates differed from the original isolates; one was considered a likely reinfection while the other may represent relapse from one of two strains initially infecting the patient. In two cases where a change in antibiotic resistance had occurred between original and relapse isolates, slight changes in RAPD patterns were found with one of the four primers used. In the other six cases the relapse was clearly due to the original strain re-emerging unchanged, with identical RAPD patterns with all four primers.
Prevalence of hepatitis A antibody among disadvantaged gypsy children in northern Spain
Authors: Cilla G. , Perez-Trallero E. , Marimon J. M. , Erdozain S. , Gutierrez C. 
Published: May 2009

SummaryThe prevalence of antibody to hepatitis A virus (HAV) in a group of socially and economically disadvantaged Spanish gypsy children was compared to that of a group of non-gypsy middle-class children. The study included 438 children, 73 gypsies (38 girls and 35 boys, mean age 8·5 years, age range 2–16 years) and 365 non-gypsy controls, randomly selected by age. The presence of anti-HAV was investigated using ELISA.Among the gypsy children, 82% had antibodies to HAV compared with 9·3% of the children in the control group. The unfavourable living conditions of the gypsy population (e.g. homes with poor sanitary conditions, overcrowding) may explain the high prevalence of HAV infection. These findings underline the need for specific action which targets disadvantaged populations.
Antigenic analysis of SAT 2 serotype foot-and-mouth disease virus isolates from Zimbabwe using monoclonal antibodies
Authors: Davidson F. L. , Crowther J. R. , Nqindi J. , Knowles N. J. , Thevasagayam S. J. , Van Vuuren C. J. 
Published: May 2009

SummaryThis paper compares strains of foot-and-mouth disease (FMD) serotype SAT (South African Territories) 2 viruses isolated from Zimbabwe and other African countries using monoclonal antibodies (MAb). A sandwich-ELISA was used to examine the relative binding of anti-SAT 2 MAb to the various viruses. The MAb-binding profiles of viruses isolated from field samples were compared using hierarchical cluster analysis. Viruses were obtained from game animals, mainly African buffalo (Syncerus caffer) which is the natural host and reservoir for SAT serotypes in Africa, and from cattle showing clinical signs of FMD, as well as from animals suspected of carrying the virus subclinically. Some isolates have been adapted for use as vaccine strains. The results showed that most of the Zimbabwe isolates collected between 1989 and 1992 were an antigenically closely-related group. Although differences were observed between Zimbabwe isolates collected between 1989 and 1992 and those collected in 1987, there was no correlation with the different MAb binding patterns within the 1987 group and the epidemiological information received from the field. Similar profiles were observed for many SAT 2 viruses, including viruses isolated over a 50-year period and from geographically distant areas. This indicates an inherent stability in antigenic profiles of SAT 2 viruses. The MAb panel was capable of assessing antigenic variation, since very different profiles were obtained for some isolates. The work also allowed comparison and characterization of anti-type SAT 2 MAb from different laboratories. The findings are discussed with reference to selection of vaccine strains.
Epidemiological investigation of an outbreak of meningococcal meningitis in Makkah (Mecca), Saudi Arabia, 1992
Authors: Al-Gahtani Y. M. , El Bushra H. E. , Al-Qarawi S. M. , Al-Zubaidi A. A. , Fontaine R. E. 
Published: May 2009

SummaryDuring March and April of 1992, the health surveillance system began detecting increasing numbers of cases of meningococcal disease (MCD) in the Islamic holy city of Makkah (Mecca). We identified 102 bacteriologically confirmed cases (CC) and 80 suspected cases (SC) of MCD. Neisseria meningitidis was identified as Group A. III-1 clone. The ratio of male:female cases was 2·9:1. All age groups of males were affected. There was only one case among women aged 10–30; 50% of the adult female cases were 55 or older. The case-fatality ratio (CFR) was 14·7% among CC. Pakistanis, who comprised about one-third of the CC. had a CFR of 26·7%. Fifty-nine percent of CC were religious visitors. CC in residents were most common in persons living near the Holy Mosque (Haram), where the carriage rate reached 86%. A mass vaccination program against MCD was instituted, using AC bivalent meningococcal vaccine (MCV). An abrupt drop, from a mean of 15 CC per week to 2 CC per week (only in visitors), coincided with vaccinating 600000 persons over 2 weeks. Makkah residents who had been vaccinated against MCD were less likely to have contracted MCD (OR = 0·17, 95% CI: 0·06–0·50). MCV was of no significant protective value if it had been administered 5 years before the outbreak. The main reason for not being vaccinated as stated by both cases (71%) and controls (45%) was not knowing about the disease. The age and sex differences probably relate to differences in exposures to crowded conditions. Health education should illuminate the seriousness of the disease and the importance of vaccination.
Targeted vaccination with meningococcal polysaccharide vaccine in one district of the Czech Republic
Authors: Kriz P. , Vlckova J. , Bobak M. 
Published: May 2009

SummaryVaccination againstNeisseria meningitidisis not part of routine immunization schemes in any country; instead, targeted vaccination of groups at the highest risk is recommended during outbreaks and epidemics. After a long period of sporadic occurrence of meningococcal invasive disease, a new clone ofNeisseria meningitidisC: 2a: P1.2, ET-15/37, occurred in the Czech Republic, and caused local outbreaks in two neighbouring districts, Olomouc and Bruntal, in spring 1993. In Olomouc, a mass campaign was conducted during which 6191 students were vaccinated (5·6 % of the total population of this locality and 96% of all students in the age group 15–19) within 2 weeks in June 1993. In Bruntal district, no such campaign was organized. In Olomouc, the incidence of invasive disease caused byNeisseria meningitidisC in the age group 10–24 decreased from 57 to 0 per 100000 (P < 0·001) during the post-vaccination period (July 1993–August 1994), but no such decrease was observed in Bruntal. Although other factors can affect the frequency of disease, these results support the current recommendations of targeted vaccination in outbreaks of meningococcal disease.
The role of heightened surveillance in an outbreak ofEscherichia coliO157. H7
Authors: Roberts C. L. , Mshar P. A. , Cartter M. L. , Hadler J. L. , Sosin D. M. , Hayes P. S. , Barrett T. J. 
Published: May 2009

SummaryAfter instituting laboratory screening forEscherichia coliO157. H7, a Connecticut hospital isolated the organism from four persons in September 1993. As a result, an outbreak ofE. coliO157.H7 associated with a country club was detected. The club had served hamburger from the same shipment at two picnics. Attendees of two picnics were interviewed, stool cultures were obtained from symptomatic persons, and the remaining hamburger was cultured. Twenty (22%) of 89 persons who ate hamburger became ill, compared with 1 of 60 who did not eat hamburger (relative risk = 13·5, 95% confidence interval 3·2–56·3). Among persons who ate hamburgers, illness was strongly associated with eating hamburger that was not thoroughly cooked (P< 0·001). All 20 samples from 5 remaining boxes of patties yieldedE. coliO157.H7. Isolates from hamburger and case-patients were indistinguishable by pulsed-field gel electrophoresis. Heightened surveillance can rapidly identify outbreaks and may mitigate their impact. However, continued review of food safety issues is necessary ifE. coliO157.H7 outbreaks are to be prevented.
Effect of changes in processing to improve hygiene control on contamination of poultry carcasses with campylobacter
Authors: Mead G. C. , Hudson W. R. , Hinton M. H. 
Published: May 2009

SummaryExamination of neck skin and caecal samples taken at a commercial processing plant from 15 randomly chosen poultry flocks showed that all flocks were contaminated initially with thermophilicCampylobacterspp., even in the apparent absence of caecal carriage. During processing, numbers of campylobacter on skin samples were reduced by between 10 and 1000-fold.To improve hygiene control generally, chlorinated-water sprays were used to limit microbial contamination on equipment and working surfaces. In addition, chlorine concentrations in process water were increased and any unnecessary carcass contact surfaces in the processing plant were removed. When comparing flocks before and after the changes, it was found that numbers of campylobacter on packaged carcasses were significantly lower after the changes had been made (P0·001). In practice, however, the reduction would be likely to have little impact on consumer exposure to campylobacter infection.
Measles vaccination policy
Authors: Williams B. G. , Cutts F. T. , Dye C. 
Published: May 2009

SummaryWhere immunization campaigns locally eliminate measles, it will be important to identify the vaccination policy most likely to prevent future epidemics. The optimum age for vaccination depends on the rate of decline of maternal antibody, because the presence of antibody reduces vaccine efficacy. The first part of this paper contains a quantitative reappraisal of the data on antibody decline and seroconversion rates by age. The decline in maternal antibody protection follows delayed exponentials, with delays of 2–4 months, and subsequent half-lives of 1–2 months. Using this result in an analytical mathematical model we find that the optimal age to administer a single dose of vaccine to children, which is independent of vaccine coverage, lies within the range 11–19 months. We also show that, where the optimal age cannot be met, it is better to err towards late rather than early vaccination. There are therefore two reasons why developing countries, which presently vaccinate during infancy because measles transmission rates are high should eventually switch to the second year of life. The possible gains from two-dose vaccination schedules are explored with respect to both coverage and efficacy. A two-dose schedule will be beneficial, in principle, only when there is a need to increase net vaccine efficacy, after coverage has been maximized with a one-dose schedule.
Epidemiological aspects of group B streptococci of bovine and human origin
Authors: Jensen N. E. , Aarestrup F. M. 
Published: May 2009

SummaryRestriction fragment length polymorphism of the gene encoding rRNA (ribotyping) was used in combination with conventional epidemiological markers to study phenotypic variations amongStreptococcus agalactiaeof bovine origin and the possible epidemiological interrelationship between the bovine and human reservoirs ofStreptococcus agalactiae.The bovine material constituted 53 strains (9 antigen combinations) isolated from 11 herds. Herds with a uniform as well as heterogenic antigenic pattern were included. Furthermore, strains isolated in the course of time from the same persistently infected quarters were examined. The human material constituted 16 strains, 4 each of 4 serotypes, isolated from healthy carriers. Finally, nine serotype- and the group reference strains were examined. All strains were serotyped by double diffusion in agarose gel, biotyped (lactose ±), and ribotyped using two restriction enzymes,HindIII andHhaI.All isolates could be typed by ribotyping and seven ribotypes were identified among the reference strains. The restriction enzymes used alone or in combination gave typing results that allowed discrimination between and within serotype. Combined use of serotype,HindIII andHhaI ribotypes produced 11 types among the 16 human strains. Ribotype analysis discriminated between herds infected with the same serotype. Strains of varying antigenic patterns from the same herd had the same ribotype. Phenotypic variations in serotype observed in persistent intramammary infection were not related to genetic changes as monitored by ribotype. Two ribotypes were represented among both bovine and human strains. The discriminating capability of lactose fermentation was of limited value.
A milk-borne campylobacter outbreak following an educational farm visit
Authors: Evans M. R. , Roberts R. J. , Ribeiro C. D. , Gardner D. , Kembrey D. 
Published: May 2009

SummaryAfter a nursery school trip to a dairy farm, 20 (53%) of 38 children and 3 (23%) of 13 adult helpers developed gastrointestinal infection. Campylobacter jejuni was isolated from 15 primary cases and from 3 of 9 secondary household cases. A cohort study of the school party found illness to be associated with drinking raw milk (relative risk 5·4, 95 % confidence interval 1·4–20·4, P = 0·001). There was a significant dose response relationship between amount of raw milk consumed and risk of illness (X2-test for linear trend 12·1, P = 0·0005) but not with incubation period, severity of symptoms or duration of illness. All 18 human campylobacter isolates were C. jejuni resistotype 02 and either biotype I (number 16) or biotype II (number 2). Campylobacter was also isolated from samples of dairy cattle and bird faeces obtained at the farm but these were of different resisto/biotypes. Educational farm visits have become increasingly popular in recent years and this outbreak illustrates the hazard of exposure to raw milk in this setting.
Plasmid profiles, restriction fragment length polymorphisms and O-serotypes amongVibrio anguillarumisolates
Authors: Pedersen K. , Tiainen T. , Larsen J. L. 
Published: May 2009

SummaryA total of 279Vibrio anguillarumstrains were serotyped and examined for plasmid content. Plasmids were subjected to digestion with restriction enzymes. Most strains belonged to serogroup O1 (39%) and O2 (16%). In total 164 strains (53%) carried plasmids. Of the O1 and O2 isolates, 92% and 30%, respectively, carried one or more plasmids. Restriction fragment length polymorphism (RFLP) analysis of plasmid DNA indicated that plasmids belonged to several groups. Each group seemed to be restricted to a single O-serovar. The largest group was the pJM1-like plasmids among most serovar O1 strains. Most of these plasmids were about 67 kb like the pJM1 plasmid, but various derivatives ranged from 26–77 kb. RFLP studies of the 67 kb plasmids revealed 17 different restriction patterns. Some patterns were dominant among European strains whereas others were dominant among North American strains. The results confirmed the applicability of O-serotyping together with plasmid profile and restriction analysis of plasmids for typing ofV. anguillarum. They also indicated that plasmids among strains which belonged to the traditional fish pathogenic serogroups, O1 and O2, showed more homology than did strains from most other serogroups, that were usually non-pathogenic, environmental bacteria.
Tuberculosis outbreak in a Texas prison, 1994
Authors: Bergmire-Sweat D. , Barnett B. J. , Harris S. L. , Taylor J. P. , Mazurek G. H. , Reddy V. 
Published: May 2009

SummaryIn 1994 a Texas prison containing a population of mentally retarded inmates experienced a large tuberculosis outbreak. Fifteen cases of tuberculosis were identified (8 confirmed by positive cultures forMycobacterium tuberculosis) and more than 100 inmates became infected. The culture-confirmed patients were infected with an identical strain of tuberculosis as demonstrated by polymerase chain reaction (PCR) based DNA fingerprinting technique. The prison followed standard tuberculosis infection control policies, but these controls were inadequate to prevent tuberculosis transmission in this special population. Two hundred and thirty inmates (119 inmates showing evidence of new tuberculosis infection or active disease and 111 healthy controls) were enrolled in the investigation. Inmate cell assignments, job duties, and educational classes were identified and medical chart reviews were conducted on all inmates. Tuberculosis transmission was associated with residing on the D Wing of the prison (OR = 25·84,P< 0·01), attending school in Classroom A (OR = 8·34,P= 0·01) and working on the prison utility work crew (OR = 2·52,P< 0·01). The index case in the outbreak had been prescribed 6 months of isoniazid (INH) chemoprophylaxis in 1988.
Severe giardiasis and cryptosporidiosis in Scotland, UK
Authors: Robertson L. J. 
Published: May 2009

SummaryHospital discharge data from 1990–4 for 26 hospitals were used to estimate and compare the cost and describe the epidemiology of severe giardiasis and cryptosporidiosis in Scotland, UK. The incidence of severe cryptosporidiosis was almost double that of severe giardiasis and the median duration of hospitalization was longer for cryptosporidiosis than giardiasis. Impaired immunity was frequently listed as co-diagnosis with cryptosporidiosis and associated with extended hospitalization. Although both infections were associated with infants, the median age was lower for cryptosporidiosis (5 years compared with 30 years). Whereas hospitalization was not significantly longer for infants with cryptosporidiosis, hospitalization for this age group with giardiasis was longer (4 days compared with 3 days). Comparison with similar data for giardiasis from USA revealed various differences and similarities. These points are discussed in relation to the epidemiology of these infections and published data were used to estimate costs of hospitalization.
Trimethoprim resistance gene inShigella dysenteriae1 isolates obtained from widely scattered locations of Asia
Authors: Haider K. , Chatkaeomorakot A. , Kay B. A. , Talukder K. A. , Taylor D. N. , Echeverria P. , Sack D. A. 
Published: May 2009

SUMMARYTrimethoprim-resistance genes ofShigella dysenteriae1 strains, isolated from a different location of six different countries of Asia over a 5-year period were characterized by using three different dihydrofolate reductase (DHFR) gene probes. The trimethoprim-resistant (TMPR) strains hybridized only with the type I DHFR gene probe by colony hybridization. None of the strains hybridized with types II and III DHFR gene probes. Southern blot experiments using plasmid DNA extracted from these resistant strains indicated that the type I DHFR genes were either on a 20 MDa plasmid or might be located on the chromosome. None of the other plasmids present inS. dyysenteriae1 strains hybridized with the probe. This indicates that the TMP resistance in theseS. dysenteriae1 strains are mediated by type I DHFR enzyme, and there may be transposition of this type I DHFR gene occurs between the 20 MDa plasmid and the chromosome in this serotype of shigella.
Vaccine prophylaxis of abattoir-associated Q fever: eight years' experience in Australian abattoirs
Authors: Marmion B. P. , Ormsbee R. A. , Kyrkou M. , Wright J. , Worswick D. A. , Izzo A. A. , Esterman A. , Feery B. , Shapiro R. A. 
Published: May 2009

SUMMARYDuring the period 1981–8 a clinical trial of a Q fever vaccine (Q-vax; Commonwealth Serum Laboratories, Melbourne) has been conducted in abattoir workers and other at-risk groups in South Australia. Volunteers in four abattoirs and visitors to the abattoirs were given one subcutaneous dose of 30 μg of a formalin-inactivated, highly-purifiedCoxiella burnetiicells, Henzerling strain, Phase 1 antigenic state, in a volume of 0·5 ml.During the period, over 4000 subjects have been vaccinated and the programme continues in the abattoirs and related groups. ‘Common’ reactions to the vaccine comprised tenderness and erythema, rarely oedema at the inoculation site and sometimes transient headache. Two more serious ‘uncommon’ reactions, immune abscess at the inoculation site, were observed in two subjects, and two others developed small subcutaneous lumps which gradually dispersed without intervention.Protective efficacy of the vaccine appeared to be absolute and to last for 5 years at least. Eight Q fever cases were observed in vaccinees, but all were in persons vaccinated during the incubation period of a natural attack of Q fever before vaccine-induced immunity had had time (≥ 13 days after vaccination) to develop. On the other hand, 97 Q fever cases were detected in persons working in, or visiting the same abattoir environments.Assays for antibody and cellular immunity showed an 80–82% seroconversion after vaccination, mostly IgM antibody to Phase 2 antigen, in the 3 months after vaccination. This fell to about 60%, mostly IgG antibody to Phase 1 antigen, after 20 months. On the other hand, 85–95% of vaccinees developed markers of cell mediated immunity as judged by lymphoproliferative responses withC. burnetiiantigens; these rates remained elevated for at least 5 years.The Q fever vaccine, unlike other killed rickettsial vaccines, has the property of stimulating long-lasting T lymphocyte memory and this may account for its unusual protective efficacy as a killed vaccine.