bluuebunny/crossref_metadata_2025_split huggingface dataset:
Papillary Variation in Coliform Bacteria
Authors: Stewart F. H. 
Published: May 2009

Papillaryvariation includes all heritable changes of character which take place in the papillae of bacterial colonies and the corresponding variations in liquid media.The following is a short summary of what is known about these variations. Papillary variation was first observed inB. coli-mutabile, and other coliform bacteria show the same variations. This race forms white colonies on lactose neutral-red plates. After 1–5 days’ incubation minute papillae, which become red and increase in size, appear on their surfaces. Subcultures from thesepapillae give colonies of two kinds, white and red. The white colonies continue to throw red, the reds breed true (Neisser, 1906; Massim, 1907). Similar variation to different sugars occurs in other related bacteria:B. dysentenaeSonne varies to lactose,B. dysentenaeMexner to maltose,B. paracolonto saccharose,B. coh-mutabile, B. acidi-lacticiandB. typhosusto dulcite (Twort, 1907; Reiner Miiller, 1909; Burn, 1910; Stewart, 1926, 1927). Vacation takes place only on the sugar concerned, but, once it has taken place, the character remains fixed, even after long growth on other media. Variation is not determined by length of exposure to the sugar. It occurs at (or after) the end of the logarithmic phase. If this phase is kept going by daily subculture (in the appropriate sugar) the bacteria of the chain carried on from culture to culture do not vary, however long they are exposed (Stewart, 1927; Deere, Dulaney & Michelson, 1939). On the other hand, if the logarithmic phase is curtailed by heavy inoculation of a culture, variation occurs early (Stewart, 1927). If the bacterium is grown on a plate without sugar until the colonies are well formed and the sugar is then added, with care not to disturb the colonies, variants appear after very short exposure (Stewart, 1927, 1928). A variation 33–2 may be completed in, two distinct steps; thus a race ofB. typhosusformed white colonies on dulcite with pink papillae, subcultures from which gave white and pink colonies; the pink colonies formed dark red papillae from which on subculture came pink and dark red colonies, the latter bred true.
Optimal plane beams modelling elastic linear objects
Authors: Koh Sung K. , Liu Guangjun 
Published: May 2009

SUMMARYThis paper discusses analytical and deterministic models for a plane curve with minimum deformation that may be utilized in planning the motion of elastic linear objects and investigating the inverse kinematics of a hyper-redundant robot. It usually requires intensive computation to determine the configuration of elastic linear objects. In addition, conventional optimization-based numerical techniques that identify the shape of elastic linear objects in equilibrium involve non-deterministic aspects. Several analytical models that produce the configuration of elastic linear objects in an efficient and deterministic manner are presented in this paper. To develop the analytical expressions for elastic linear objects, we consider a cantilever beam where the deflections are determined according to the Euler–Bernoulli beam theory. The deflections of the cantilever beam are determined for prescribed constraints imposed on the deflections at the free end to replicate various elastic linear objects. Deflections of a cantilever beam with roller supports are explored to replicate elastic linear objects in contact with rigid objects. We verify the analytical models by comparing them with exact beam deflections. The analytical model is precisely accurate for beams with small deflections as it is developed on the basis of the Euler–Bernoulli beam theory. Although it is applied to beams undergoing large deflections, it is still reasonably accurate and at least as precise as the conventional pseudo-rigid-body model. The computational demand involved in using the analytical models is negligible. Therefore, efficient motion planning for elastic linear objects can be realized when the proposed analytical models are combined with conventional motion planning algorithms. We also demonstrate that the analytical model solves the inverse kinematics problem in an efficient and robust manner through numerical simulations.
Comparison of pulsed-field gel electrophoresis and ribotyping for subtyping ofVibrio choleraeO139 isolated in Thailand
Authors: Dalsgaard A. , Skov M. N. , Serichantalergs O. , Echeverria P. 
Published: May 2009

SummaryPulsed-field gel electrophoresis (PFGE) ofCpoI-digested genomic DNA and ribotyping (BglI) were applied to 60Vibrio choleraestrains including 48V. choleraeO139 from Thailand to compare their value in differentiating strains of the presentV. choleraeO139 epidemic. PFGE patters were divided into groups A and B representing five and four subtypes, respectively, while ribotyping showed four different patterns. PFGE group B subtypes were only presented among O139 isolates from Thailand, whereas four O139 strains from Bangladesh and India showed identical PFGE group A subtypes observed in O139 isolates from Thailand. Two nontoxigenic O139 isolates from Thailand showed different and unique PFGE types as did fiveV. choleraenon-Ol non-O139 isolates containing a gene virulence complex found inV. choleraeO139. These results indicate that PFGE (CpoI) can resolve recent evolutionary divergence withinV. choleraeO139 and offers a useful supplementary tool for following the progressingV. choleraeO139 epidemic.
World Health Organisation – supervised interlaboratory comparison of ELISAs for the serological detection ofSalmonella entericaserotype Enteritidis in chickens
Authors: Barrow P. A. , Desmidt M. , Ducatelle R. , Guittet M. , van der Heijden H. M. J. F. , Holt P. S. , Huis in't Velt J. H. J. , McDonough P. , Nagaraja K. V. , Porter R. E. , Proux K. , Sisak F. , Staak C. , Steinbach G. , Thorns C. J. , Wray C. , van Zijderveld F. 
Published: May 2009

SummaryA collaborative exercise, supervised by the World Health Organisation, was set up to compare ELISAs used for the serological detection ofSalmonella enteriticaserotype Enteritidis in chickens. The aim was to ascertain how far agreement could be reached on the interpretation of optical density readings for high titre, intermediate titre and low titre sera. Two sets of sera were sent to 14 participants. The first set compared high, medium and low titre sera raised in specified-pathogen-free and commercial broiler breeder chickens. The second set comprised 20 sera of different antibody titres raised in commercial birds reared under laboratory conditions and sent blind. Both indirect and double-antibody sandwich blocking ELISAs were used with a number of different detecting antigens. With a few exceptions good agreement was reached on the interpretation of results obtained from high and low titre sera from the optical density obtained with a single serum dilution. Differences were observed in the interpretation of medium titre sera. The results suggested that most ELISAs produce reasonably comparable results and that practical problems may arise from interpretation of the results mainly as a result of the choice of the criteria used for differentiating sera obtained from infected and uninfected chickens. These problems are discussed.
Antibiotic prescribing during an outbreak of meningococcal disease
Authors: Stuart J. M. , Robinson P. M. , Cartwright K. , Noah N. D. 
Published: May 2009

SummaryDuring a prolonged outbreak of meningococcal disease caused by serogroup B serotype 15 sulphonamide-resistant strains in one British health district, there was considerable variation in attack rates by town. General practitioner (GP) antibiotic prescribing rates were compared in high and low incidence towns. The only significant difference found was that erythromycin prescribing was more frequent in the high incidence towns (rate ratio 4·0, 95% CI 3·2–4·8, in March 1987 and 3·0, 95% CI 2·4–3·7, in November 1987). This was probably due to increased GP consultation rates for upper respiratory tract infection (URTI), but higher erythromycin usage may have increased meningococcal acquisition rates or susceptibility to meningococcal disease. Antibiotic prescribing rate should be further investigated in defined areas of high and low incidence of meningococcal disease.
Respiratory syncytial virus infection and meningococcal disease
Authors: Stuart J. M. , Cartwright K. , Andrews N. J. 
Published: May 2009

SummaryAlthough viral respiratory tract infections may predispose to meningococcal disease, strong evidence that they do so exists only for influenza. Data on laboratory reported cases of respiratory syncytial virus (RSV) infections and meningococcal disease in England and Wales from mid-1989 to mid-1994 were analysed. Although the rise in RSV cases preceded the rise in meningococcal disease cases each winter, the interval between the rise and fall of the two diseases was inconsistent, no association was found between time series after removal of the seasonal component, and there was no evidence that more cases of meningococcal disease occurred in winters with more RSV disease. RSV may have less effect on the two most likely mechanisms whereby influenza predisposes to meningococcal disease, namely lowered immunity and impaired pharyngeal defences.
Microbiology of HIV associated bacteraemia and diarrhoea in adults from Nairobi, Kenya
Authors: Batchelor B. I. F. , Kimari J. N. , Brindle R. J. 
Published: May 2009

SummaryWe undertook a retrospective descriptive comparison of the spectrum of pathogens responsible for bacteraemia and diarrhoea in HIV antibody positive and negative patients over 4 years (1988–92), in Nairobi, Kenya. The study population was recruited from primary to tertiary centers of clinical care and consisted of 2858 adults (15 years or older). There were 415 significant blood culture isolates, 192 from 1785 HIV negative patients and 223 from 953 HIV positive patients. There were 233 significant faecal isolates, 22 from 115 HIV negative patients and 211 from 531 HIV positive patients. The most common pathogens detected in blood were Streptococcus pneumoniae and Salmonella typhimurium and in faeces Shigella flexneri, S. typhimurium and Cryptosporidium parvum. The agents causing illness in HIV positive patients in Nairobi are similar to those prevalent in the HIV negative community and the investigation of a febrile illness with or wothout diarrhoea in an HIV positive patient should reflect this.
Impact of incomplete coverage of neonatal dried blood spot screening on estimating HIV-1 seroprevalence
Authors: Hutchinson E. J. , Streetly A. , Grant C. , Pollitt R. , Eldridge P. , Nicoll A. 
Published: May 2009

SummaryThe aim of this study was to determine the extent to which selective under-coverage of births to mothers more likely to be at risk of HIV-1 infection will result in a significant underestimation of the true neonatal seroprevalence. Census data, local birth statisties, maternity data and data from the prevalence monitoring programme were used to produce a model to predict the effects of under-coverage in the uptake of neonatal metabolic screening which has been observed in babies with a mother of ethnic group black African. The adjustment factor which allows for under-coverage is the relative inclusion ratio (RIR); the probability that samples from a group at different risk of HIV infection were included in the survey divided by the probability of inclusion for samples from all other babies. The RIR was found to be close to unity (0·97), indicating a minimal bias. Under usual conditions only if the relative inclusion ratio (RIR) declined to values of 0·87 or below would there be a substantial bias. Despite some selective under representation, the results obtained from the Unlinked Anonymous HIV Monitoring Programme Dried Blood Spot Survey would seem to identity levels of prevalence in the population of child-bearing women with a good degree of accuracy and remains a useful tool for resource allocation, planning of services, provision of care and counselling.
The incidence ofCyclospora cayetanensisin stool samples submitted to a district general hospital
Authors: Clarke S. C. , McIntyre M. 
Published: May 2009

SummaryCyclospora cayetanensisis the cause of a prolonged diarrhoeal syndrome. In the UK most cases are seen in travellers who have returned from countries in which the organism is endemic. The purpose of this investigation was to determine the incidence ofC. cayetanensisin stool samples submitted to a district general hospital. A total of 6151 stools from 5374 different patients were screened for the presence ofC. cayetanensisover a 1-year period using the modified Ziehl-Neelsen technique. Oocysts ofC. cayetanensiswere found in 7 stools (0·1%) from 4 patients (0·07%). All four patients were adult travellers who had visited countries in whichC. cayetanensisis known to be endemic. In the population of this study,C. cayetanensiswas found to be a rare cause of diarrhoea. AlthoughC. cayetanensisinfection should be considered in individuals of all ages who have lived in, or have travelled to endemic areas, there is no need to screen stool samples for the organism in those without such a travel history.
Increased colonization potential of Campylobacter jejuni strain 81116 after passage through chickens and its implication on the rate of transmission within flocks
Authors: Cawthraw S. A. , Wassenaar T. M. , Ayling R. , Newell D. G. 
Published: May 2009

SummaryThe mechanisms by which Campylobacter jejuni rapidly spreads through large broiler flocks are unknown. Recent evidence suggests that the minimum infective oral dose for 100% caecal colonization is about 104 cfu, which, with such a ‘fragile’ organism, may limit transmissibility. However, the colonization potential of laboratory-adapted strains may be anomalous compared with fresh isolates or those passaged in vivo. The colonization potential of two chicken and one human C. jejuni isolates, which were minimally passaged, have been investigated using a quantitative model of chicken colonization. There was no detectable difference between these strains but all were more efficient colonizers than a laboratory-adapted strain 81116. In addition, the colonization potential of C. jejuni strain 81116 following a passage in vivo was also determined. The results indicated this increased C. 10000 fold following a single passage in vivo, such that a dose of only 40 cfu caused maximal colonization. Enhanced colonization potential may, therefore, account for the rapid rate of transmission within large flocks.
Foal diarrhoea between 1991 and 1994 in the United Kingdom associated withClostridium perfringens, rotavirus,Strongyloides westeriandCryptosporidiumspp.
Authors: Netherwood T. , Wood J. L. N. , Townsend H. G. G. , Mumford J. A. , Chanter N. 
Published: May 2009

SummaryA case control study of foal diarrhoea in the United Kingdom was carried out over a 3-year period.Clostridium perfringenswas significantly associated with foal diarrhoea (Odds Ratio (OR) = 3·0), being isolated from 57% of 421 animals with diarrhoea but from only 27% of 223 healthy foals. Also,C. perfringenswas significantly associated with fatal diarrhoea (OR = 4·5). About half of diarrhoea with a fatal outcome was attributable to this organism.The other pathogens significantly associated with diarrhoea were rotavirus (OR = 5·6), Cryptosporidium spp. (OR = 3·2) and the nematodeStrongyloides westeri, which was significant only when present in large numbers (> 2000 eggs/g of faeces: OR = 6·1).Salmonellaspp. (OR = 14·2) andCryptosporidiumspp. (OR = 3·0) were the only other pathogens associated with fatal illness.Overall,C. perfringens, rotavirus, and large numbers ofCryptosporidiumspp. orS. westeriwere isolated from 80% of foals with diarrhoea. ThermophilicCampylobacterspp.,Yersinia enterocolitica,Escherichia coliand other parasites were not associated with diarrhoea. Carriage ofC. perfringens, rotavirus andCryptosporidiumspp. was significantly greater in healthy foals in contact with cases of diarrhoea than in foals that were not in contact with diarrhoea (P < 0·05). There were no statistical interactions between any of the pathogens associated with diarrhoea although separate cases from one location often involved more than one pathogen.
The use of alkalinity and incubation at 9 °C for improved recovery ofYersiniaspp. from faeces
Authors: Greenwood Melody H. , Hooper W. L. 
Published: May 2009

SUMMARYRecovery ofYersinia enterocoliticaand related strains from faecal samples enriched in 1% buffered peptone water (pH 7·2) and incubated at 4 °C for 17–21 days was compared with recovery from 1% peptone water buffered to pH 8·0 and incubation over the temperature range 4–26°C. Best recovery was obtained by use of the alkaline medium incubated at 9°C. Greatest recovery was obtained after incubation for 10–14 days, but most strains (> 75%) were recovered after 1 week.
Species identification, antibiotic sensitivity and slime production of coagulase-negative staphylococci isolated from clinical specimens
Authors: Deighton M. A. , Franklin J. C. , Spicer W. J. , Balkau B. 
Published: May 2009

SUMMARYTwo hundred and seventy-five consecutive clinical isolates of coagulase-negative staphylococci, including strains associated with disease, contaminants and skin colonizers, were speciated, tested for slime production and for their sensitivity to a range of antibiotics.Staphylococcus epidermidiswas the most commonly identified species, comprising 63% of all isolates. Slime production was detected in half the strains ofStaph. epidermidis, Staph. haemolyticusandStaph. Saprophyticusbut was rare in other species. MostStaph. haemolyticusstrains and approximately half of theStaph. epidermidisstrains were resistant to five or more antibiotics. A significant association was found between slime production and multiple antibiotic resistance. For catheter-associated strains, clinical relevance was predictable by species i.e.Staph. epidermidis. Multi-resistant slime-positiveStaph. haemolyticusstrains, although infrequently associated with disease, were common skin colonizers, presumably acquired from the hospital environment. We describe a practical and inexpensive scheme for thespeciation of human coagulase-negative staphylococcal isolates.
Prospective study of diarrhoeal disease in a cohort of rural Mexican children: incidence and isolated pathogens during the first two years of life
Authors: Cravioto Alejandro , Reyes Rosa E. , Ortega Roberto , Fernández Guadalupe , Hernández Raymundo , López Dolores 
Published: May 2009

SUMMARYColonization of the intestine by putative pathogens was followed longitudinally in a cohort of 56 infants born during one calendar year in a rural Mexican village with faecal cultures taken every fortnight and every time a child had diarrhoea. The frequency of isolation of pathogens during episodes of diarrhoea was compared with that of matched controls from the same cohort. Incidence of diarrhoea during the first year of life was 98%, diminishing to 93% during the second year. The incidence curves for each year were not significantly different (P> 0·1). Isolation of enteropathogenicEscherichia coli, enterotoxigenicEscherichia coliproducing heat-stable (ST) and/or heat-labile (LT) enterotoxins and rotaviruses was significantly higher in infants with diarrhoea during the first 2 years of life. In the case of shigella, although no significant differences were found by semester of life, 13 of 16 children in which these strains were found had diarrhoea. Isolation ofSalmonellaspp.,Campylobacterspp. and protozoa were not significantly different in the two groups during the period studied. Strains showing localized adherence to HEp-2 cells or the presence of colonization factor antigens I or E8775 were found with significantly higher frequency in children with diarrhoea. Eighty-two percent of ST+or LT+ETEC strains isolated produced one of the three known colonization factors.
Washing with contaminated bar soap is unlikely to transfer bacteria
Authors: Heinze John E. , Yackovich Frank 
Published: May 2009

SUMMARYRecent reports of the isolation of microorganisms from used soap bars have raised the concern that bacteria may be transferred from contaminated soap bars during handwashing. Since only one study addressing this question has been published, we developed an additional procedure to test this concern. In our new method prewashed and softened commercial deodorant soap bars (0·8% triclocarban) not active against Gram-negative bacteria were inoculated withEscherichia coliandPseudomonas aeruginosato give mean total survival levels of 4·4 × 105c.f.u. per bar which was 70-fold higher than those reported on used soap bars. Sixteen panelists were instructed to wash with the inoculated bars using their normal handwashing procedure. After washing, none of the 16 panelists had detectable levels of either test bacterium on their hands. Thus, the results obtained using our new method were in complete agreement with those obtained with the previously published method even though the two methods differ in a number of procedural aspects. These findings, along with other published reports, show that little hazard exists in routine handwashing with previously used soap bars and support the frequent use of soap and water for handwashing to prevent the spread of disease.
Ontogenesis of the formation of secretory antibodies to respiratory syncytial (RS) virus
Authors: Leschinskaya N. P , Pokrovskaya E. E , Kantorovitch E. A , Grigorjeva S.K , Shvartsman YA. S 
Published: May 2009

SUMMARYExamination of sera from 184 children aged between 0 and 12 years and 161 adults revealed a close correlation between age and the level of humoral anti-RS virus immunity. Secretory IgG antibodies were found in children in their first months of life. Evidence for their release into secretions from the serum was obtained. This might explain the positive correlation between serum antibody levels in women recently confined with the morbidity due to RS virus in children during their first months of life. Secretory IgA antibodies were found from 4 months untill old age. The secretions of children and adults contained virus-neutralizing activity which was non-immunoglobulin in nature, as well as antibodies. However, in contrast to secretory antibody this material did not prevent development of severe RS virus infections.
Nosocomial legionella pneumonia: demonstration of potable water as the source of infection
Authors: Ruf B. , Schürmann D. , Horbrach I. , Seodel K. , Pohle H. D. 
Published: May 2009

SUMMARYFrom January 1983 until December 1985, 35 cases of sporadic nosocomial legionella pneumonia, all caused byLegionella pneumophila, were diagnosed in a university hospital.L. pneumophilaserogroup (SG) 1 was cultured from 12 of the 35 cases and compared to correspondingL. pneumophilaSG 1 isolates from water outlets in the patients' immediate environment by subtyping with monoclonal antibodies. The corresponding environmental isolates were identical to 9 out of 12 (75%) of those from the cases. However, even in the remaining three cases identical subtypes were found distributed throughout the hospital water supply. From the hospital water supply four different subtypes ofL. pneumophilaSG 1 were isolated, three of which were implicated in legionella pneumonia. Of 453 water samples taken during the study 298 (65.8%) were positive for legionellae. Species ofLegionellaother thanL. pneumophilahave not been isolated. This may explain the exclusiveness ofL.pneumophilaas the legionella pneumonia-causing agent. Our results suggest that the water supply system was the source of infection.