Additional glycosylation at the receptor binding site of the hemagglutinin (HA) for H5 and H7 viruses may be an adaptation to poultry hosts, but does it influence pathogenicity?

Sequence analysis of the hemagglutinin (HA) gene of H5 and H7 viruses was used to determine phylogenetic relationships between high-pathogenicity avian influenza (HPAI) and low-pathogenicity avian influenza (LPAI) viruses from avian influenza (AI) outbreaks in Norfolk in 1979 and 1991 and Italy in 1999-2000. A common feature within these groups of viruses was the acquisition of additional glycosylation sites near the receptor binding site of the HA. Passage of H5 viruses through 14-day-old embryonated fowls' eggs readily selected viruses with additional glycosylation of HA1. Although additional glycosylation may not correlate with increased pathogenicity for fowl, it may predispose viruses to become highly pathogenic.

Genotypic and phenotypic characterization of the dynamics of the lactic acid bacterial population of adjunct-containing Cheddar cheese manufactured from raw and microfiltered pasteurised milk

AIMS

This study investigates the dynamics of the microflora, particularly the lactobacilli, in Cheddar cheese manufactured from raw and microfiltered milk containing different adjunct cultures.

METHODS AND RESULTS

Sixteen cheeses - raw milk, adjunct and control cheeses - were manufactured in four trials. Lactobacilli were identified by PCR methods in one trial, and by phenotypic typing for all trials. Numbers of lactobacilli were significantly different at day 1 and 3 months in the control and adjunct-containing cheeses. In the raw milk cheeses, Lactobacillus paracasei was detected throughout ripening, Lact. curvatus at the end, and Lact. plantarum at day 1 only. Lactobacillus strain diversity decreased from raw, control to adjunct cheeses. Enteroccoci and coliform numbers further differentiated raw cheeses from the others. Lactococcal starter numbers also differed in the three cheese types and differences were observed within adjunct cheeses. Although adjunct lactobacilli dominated in the cheese to which they were added, strains with similar phenotypic profiles were also detected on occasions in some of the control cheeses.

CONCLUSIONS

The addition of adjunct lactobacilli modified the growth kinetics of both adventitious lactobacilli and starter lactococci during ripening. Appropriate strain tracking is necessary to monitor changes in the population profiles of control and experimental cheeses in trials utilizing adjunct cultures.

SIGNIFICANCE AND IMPACT OF THE STUDY

Investigations of the role of adjunct strain(s) in cheeses may be complicated by the interactions between the adjunct and the other cheese strains, and effective strain monitoring by genotypic or phenotypic methods is essential if valid comparisons are to be made.

A molecular epidemiological study of avian paramyxovirus type 1 (Newcastle disease virus) isolates by phylogenetic analysis of a partial nucleotide sequence of the fusion protein gene

A sequence 375 nucleotides in length, which included the region encoding the cleavage activation site and signal peptide of the fusion protein gene, was determined for 174 isolates of Newcastle disease virus (avian paramyxovirus type 1). These were compared with the sequences of 164 isolates published on GenBank, and the resulting alignment was analysed phylogenetically using maximum likelihood. The results are presented as unrooted phylogenetic trees. Briefly, the isolates divided into six broadly distinct groups (lineages 1 to 6). Lineages 3 and 4 were further subdivided into four sublineages (a to d) and lineage 5 into five lineages (a to e). Considerable genetic heterogeneity was detected within avian paramyxoviruses type 1, which appears to be influenced by host, time and geographical origin. It is concluded that by using this dataset it will be possible to type future virus isolates rapidly on the basis of their nucleotide sequence and make inferences about their origins.

Long term variation in water colour from Yorkshire catchments

Water colour is a problem in the upland water-gathering grounds of the UK. It has shown considerable variation over recent years and this needs to be put into the longer-term context. In order to do this, factors to convert water colour measured in absorbance units per metre (Au/m) to Hazen units are presented for ten sites in the Yorkshire region using data from August 1997 to June 1998. The conversion factors are site-specific and there is some evidence that they may show seasonal variation. There is also a short-term upward trend in the conversion factor for a number of catchments, which may be related to their recovery following the 1995 drought. Time series of water colour in Hazen from 1980 to 1998 are shown for selected sites. The seasonal variation in colour levels is disrupted at all sites during and following drought periods, notably 1990-1992 and 1995-1998 and, in the case of two sites with long-term colour measurements, the 1975-1976 drought. These periods are followed by enhanced levels of colour and, since the end of the 1995 drought, unprecedented high values have been recorded at some catchments.

Changes in the haemagglutinin and the neuraminidase genes prior to the emergence of highly pathogenic H7N1 avian influenza viruses in Italy

Outbreaks of avian influenza due to an H7N1 virus of low pathogenicity occurred in domestic poultry in northern Italy from March 1999 until December 1999 when a highly pathogenic avian influenza (HPAI) virus emerged. Nucleotide sequences were determined for the HA1 and the stalk region of the neuraminidase (NA) for viruses from the outbreaks. The HPAI viruses have an unusual multibasic haemagglutinin (HA) cleavage site motif, PEIPKGSRVRRGLF. Phylogenetic analysis showed that the HPAI viruses arose from low pathogenicity viruses and that they are most closely related to a wild bird isolate, A/teal/Taiwan/98. Additional glycosylation sites were present at amino acid position 149 of the HA for two separate lineages, and at position 123 for all HPAI and some low pathogenicity viruses. Other viruses had no additional glycosylation sites. All viruses examined from the Italian outbreaks had a 22 amino acid deletion in the NA stalk that is not present in the N1 genes of the wild bird viruses examined. We conclude that the Italian HPAI viruses arose from low pathogenicity strains, and that a deletion in the NA stalk followed by the acquisition of additional glycosylation near the receptor binding site of HA1 may be an adaptation of H7 viruses to a new host species i.e. domestic poultry.

Analytical approaches to measuring cospeciation of host and parasites: through a glass, darkly

Studies of cophylogenetic associations between hosts and parasites have become increasingly common. Historically, congruence between host and parasite phylogenies has been seen as evidence for cospeciation. Analyses of such coevolutionary relationships, however, are made extremely difficult by the complex interplay of cospeciation, host switching, sorting (extinction), duplication (intrahost speciation) and inertia (lack of parasite speciation) events, all of which may produce incongruence between host and parasite phylogenies. Here we review several methods of analysing cospeciation. We illustrate these methods with an example from a Procellariiformes (seabird) and chewing louse (Halipeurus) association.

Membrane inlet mass spectrometric measurement of O2 and CO2 gradients in cultures of Lactobacillus paracasei and a developing Cheddar cheese ecosystem

Membrane inlet mass spectrometry was used to measure O2 and CO2 as depth profiles in stab cultures of 0.1% agar Man Rogosa Sharpe medium inoculated with Lactobacillus paracasei CI3. Diffusion of CO2 from the central column of growth into the medium was observed to show lower concentrations where bacteria were absent. CO2 profiles developed in a manner similar to those in Cheddar cheese and O2 was undetectable at similar depths. Gases were analysed in Cheddar cheese over a maturation period of 200 d. O2 was detectable to depths of 13, 6 and 2.5 mm on days 2, 9 and 15, respectively, but then became undetectable at depths of 2.5-3 mm. CO2 concentrations measured within the cheese increased 10-fold from day 2 to day 200 to reach a value of around 15 mM. The progress of measured CO2 concentration over time at a given depth in cheese shows a hyperbolic type increase. Coefficient of regression values increase with depth to a maximum value of R2 = 0.93. In both systems, reductions and increases in CO2 were due to the absence or presence of bacterial growth, respectively. Confocal scanning laser and scanning electron microscopy was used to show spatial heterogeneity of microcolonies within the cheese ecosystem. This information can potentially be used as a non-sensory evaluation of cheese maturity status. Measurement of gases in a cheese ecosystem provides the first description of mass spectrometry being used to monitor the processes of microbial gaseous exchange with respect to O2 and CO2 in a cheese ecosystem.

Doing things with illness. The micro politics of the CFS clinic

This paper focuses on lay and professional ideas about the nature of chronic fatigue syndrome (CFS), and in particular, the ways in which understandings of the disorder are developed in a clinical setting. Our data are drawn from observations of consultations between sufferers and physicians in a UK medical out-patients clinic. We treat the clinic as a political field. That is to say, as an arena in which 'problems' (about the management of illness) are constituted, and alternative approaches and solutions to such problems are pressed. We note that in the realms of symptoms, aetiology and treatment evaluation, lay people in the CFS clinic have quite distinct ideas about what their problems are and how they might be analysed and managed--ideas that are often in conflict with those of medical professionals. Thus, lay sufferers, for example, operate within a different conceptual terrain from that of many professional experts. They are more likely to refer to a disease (myalgic encephalomyelitis or ME), rather than a syndrome. They call upon different kinds of hypotheses to explain their symptoms. They hold to conflicting ideas about the order of causal sequences, and they give emphasis to different kinds of phenomena in their accounts of illness. As a consequence, clinical consultations can often take on the form of a political contest between physician and patient to define the true and real nature of the patient's disorder--a micro political struggle in which neurological symptoms can be re-framed as psychiatric symptoms, and psychiatric symptoms as neurological. In short, a contest in which the demarcation lines between mind and body are continually assessed and re-defined, and the tenets of 'biomedicine' are constantly challenged.

H9N2 subtype influenza A viruses in poultry in pakistan are closely related to the H9N2 viruses responsible for human infection in Hong Kong

Following the outbreak of H5N1 "bird flu" in Hong Kong in 1997, the isolation of H9N2 subtype viruses from patients in southern China and Hong Kong SAR once again raised the spectre of a possible influenza pandemic. H9N2 viruses have recently been responsible for disease in poultry in various parts of the world and preliminary studies of the H9 haemagglutinin (HA) genes of viruses isolated during 1998 and 1999 in Germany, Iran, Pakistan, and Saudi Arabia showed a close relationship to the HA genes of the viruses that infected two children in Hong Kong SAR. Analysis of the complete genome of a Pakistan isolate, A/chicken/Pakistan/2/99, showed that it is closely related in all eight genes (97-99% homology) to the human H9N2 isolates and furthermore that the six genes encoding internal components of the virus are similar to the corresponding genes of the H5N1 viruses that caused 6 (out of 18) fatal cases of human infection. Thus H9N2 viruses similar to those that caused human infections in Hong Kong are circulating more widely in other parts of the world. Whether or not these H9N2 viruses also have features that facilitate avian-to-human transmission is not known. Since avian H9N2 viruses are currently perceived to represent a significant threat to human health it is important to determine whether or not viruses of this subtype circulating in poultry in various parts of the world have the potential to infect people.

Endoscopic ultrasound guided biopsy of sub-carinal lymph nodes

AIM/METHODS

Endoscopic ultrasound (EUS) guided biopsy is not widely available in the U.K., and sub-carinal nodes can be difficult to biopsy percutaneously. Tissue obtained from these nodes can influence patient management. We describe our initial experience with EUS guided transoesophageal biopsy of sub-carinal nodes using a Pentax FG-34 EUS probe and a 22 G Hancke-Villman or Echotip needle in 20 patients.

RESULTS

Malignant cells were obtained from the nodes in 13 patients, and in another patient in whom the node biopsy was negative, small cell carcinoma cells were obtained from a lesion in the liver. There were no complications.

CONCLUSIONS

Mediastinoscopy to obtain tissue, or the blind treatment of presumed malignancy was avoided in all the patients in whom a positive biopsy was obtained. In many of these patients, more conventional methods to obtain a tissue diagnosis had already failed. The problem solving capability of this safe, well-tolerated technique is discussed.Roberts, S. A. Clinical Radiology55, 832-836.

Phylogenetic analysis of H7 haemagglutinin subtype influenza A viruses

A 945 nucleotide region (bases 76-1020) of the HA1 part of the HA gene was obtained for 31 influenza viruses of H7 subtype isolated primarily from Europe, Asia and Australia over the last 20 years. These were analysed phylogenetically and compared with sequences of the same region from 23 H7 subtype viruses available in Genbank. The overall results showed two geographically distinct lineages of North American and Eurasian viruses with major sublineages of Australian, historical European and equine viruses. Genetically related sublineages and clades within these major groups appeared to reflect geographical and temporal parameters rather than being defined by host avian species. Viruses of high and low virulence shared the same phylogenetic branches, supporting the theory that virulent viruses are not maintained as a separate entity in waterfowl.

A tale of two kidneys--how long can a kidney transplant wait?

This paper compares early graft function (EGF) of the first transplanted kidney (group 1) with the kidney transplanted second (group 2) in kidney pairs from the same cadaver donor. Thirty-one pairs of kidneys were harvested from cadaver donors between January 1997 and October 1998. Each pair was transplanted using a standard technique by the same team of surgeons, one after the other, as a result of limitations in theatre time and staff availability. Incidence of acute rejection (AR), acute tubular necrosis (ATN) and need for post-transplant dialysis was recorded for both groups, and was compared using the relevant statistical methods. Patients in both groups were well matched for age, gender and mode of dialysis pre-transplant. Human leucocyte antigen (HLA) matching and panel reactive antibody (PRA) status were similar in the two groups (p > 0.05). Cold ischaemia time (CIT) in the two groups was 14.1 +/- 5.7 and 19.2 +/- 6.9 h, respectively, the difference being statistically significant (p < 0.05). The incidence of AR was similar in the two groups. However, ATN (on renogram) was significantly more common in group 2 (p < 0.05; 12 patients versus 5 patients in group 1). All patients with ATN required post-transplant dialysis. Hospital stay was significantly prolonged in group 2 patients (p < 05; 20 +/- 10.6 versus 16.3 + 6.2 d for group 1). Even a relatively short increase in CIT can cause the second transplanted kidney of a pair to have a significantly higher incidence of ATN, resulting in need for dialysis and prolongation of hospital stay. Simultaneous transplantation, in areas lacking organ sharing networks, would not only improve EGF, but also improve long term graft survival. In addition, the reduced requirement for post-transplant dialysis and a shorter hospital stay would balance any increased demand on resources.

Flexible monitoring in the management of patient care processes: a pilot study

This article describes a study conducted on the internal medicine, general surgical, and vascular wards of a large metropolitan hospital to assess the impact of a networked monitoring system and portable patient monitors. This pilot study was developed to address the need of hospital patients who require continuous noninvasive vital signs monitoring (including heart rate, noninvasive blood pressure, pulse oximetry, cardiac waveform monitoring) with the addition of surveillance from a cardiac intensive care area. Data were collected from 114 patients over a 3-month period to identify a patient group that could be managed appropriately under the new system and to determine the effect that flexible monitoring had on patient care management. Findings include identification of a specific patient group that can be managed successfully outside the cardiac intensive care area using this system. Other findings suggest a way to improve the management of patient monitoring in the general ward areas.

Complement-resistant Moraxella catarrhalis forms a genetically distinct lineage within the species

Moraxella catarrhalis is a bacterial species that has been implicated in 15-20% of all cases of otitis media in the USA and the complement-resistant variant of M. catarrhalis has been considered particularly pathogenic. A collection of geographically diverse, complement-sensitive (n=28) and -resistant strains (n=47) of M. catarrhalis was assembled in order to analyse the bacterial population structure. All strains were identified as M. catarrhalis by conventional microbiological and biochemical methods. Amplification of the small subunit (ssu) ribosomal RNA gene followed by restriction fragment length polymorphism (RFLP) analysis did not reveal consistent differences between serum-susceptible and -resistant M. catarrhalis isolates. Interestingly, upon automated ribotyping using the Qualicon RiboPrinter(R) microbial characterisation system, the complement-sensitive and -resistant strains segregated into two groups. This suggested the existence of two clearly distinguishable lineages within the species M. catarrhalis. This observation was corroborated by pulsed field gel electrophoresis (PFGE) of DNA macro-restriction fragments, a non-ribosomal PCR RFLP procedure and random amplification of polymorphic DNA (RAPD) analysis. All procedures grouped the two variants similarly. Redefinition of the taxonomic status of complement-resistant M. catarrhalis or even the definition of a new species may be opportune.

Antigenic and genetic characterisation of Newcastle disease viruses isolated from outbreaks in domestic fowl and turkeys in Great Britain during 1997

Antigenic and genetic analyses of viruses from the 11 outbreaks of Newcastle disease in Great Britain, 12 of the outbreaks in Northern Ireland and the single outbreak in the Republic of Ireland which occurred in 1997, indicated that they were all essentially similar. In addition, the viruses from the British Isles were very similar to viruses isolated from three outbreaks in pheasants in Denmark between August and November 1996, from a goosander in Finland in September 1996, from an outbreak in chickens in Norway in February 1997, and from an outbreak in chickens in Sweden in November 1997. Viruses from outbreaks in other countries during 1995 to 1997 could be distinguished antigenically and/or genetically from the 1996 to 1997 Scandinavian/British Isles isolates, as could viruses responsible for two separate outbreaks in caged birds in quarantine premises in Great Britain in March 1997. Minor nucleotide differences in the 413-base region of the fusion gene and the 187-base region of the haemagglutinin-neuraminidase gene sequenced in this study allowed the 1996 to 1997 Scandinavian/British Isles isolates to be divided into groups. These groups broadly corresponded to the clusters of disease outbreaks, but suggested that the discrete outbreak in Scotland was probably the result of virus spread from Northern Ireland. Overall, the antigenic and genetic analyses of these viruses were consistent with the theory that the virus was introduced into the British Isles by migratory birds moving from north-east Europe. However, it was not possible to rule out other sources, such as the movement of pheasants from Denmark.

Glycophorin A mutation Ala65 --> Pro gives rise to a novel pair of MNS alleles ENEP (MNS39) and HAG (MNS41) and altered Wrb expression: direct evidence for GPA/band 3 interaction necessary for normal Wrb expression

We report here a novel Glycophorin A (GPA) mutation Ala65 --> Pro which gives rise to a low-incidence antigen HAG, lack of a high-incidence antigen ENEP and aberrant expression of the high-incidence Wrb antigen. Anti-ENEP was identified in the serum of a transfused male patient (E.H.) who was homozygous for a GPA Ala65 --> Pro mutation and possessed a novel low-incidence antigen which we have called HAG. An unrelated HAG-positive individual, heterozygous for the Ala65 --> Pro mutation, has also been identified. Anti-HAG was present in several multispecific antisera to low-incidence antigens and in one monospecific serum. Normal expression of the Wrb antigen depends on the presence of amino acid Glu658 of band 3 and on the presence of GPA. However, a specific epitope on GPA has not previously been implicated. DNA sequence analysis of band 3 from patient E.H. was normal in the region of Wra/Wrb polymorphism with homozygous presence of Glu658 and therefore the abnormal Wrb expression results from the Ala65 --> Pro mutation in GPA. The ENEP and HAG antigens have been assigned the MNS blood group system numbers 002.039 and 002.041, respectively, by the ISBT Working Party on Terminology for Red Cell Surface Antigens.

Characterisation of an avian influenza A virus isolated from a human--is an intermediate host necessary for the emergence of pandemic influenza viruses?

The partial sequencing of the internal and the neuraminidase genes of isolate 268/96 obtained from a woman with conjunctivitis showed all seven to have closest homology with avian influenza viruses. The entire nucleotide sequence of the haemagglutinin gene of 268/96 had close, 98.2%, homology with an H7N7 virus isolated from turkeys in Ireland in 1995. This appears to be the first reported case of isolation of an influenza A virus from a human being infected as a result of direct natural transmission of an avian influenza virus from birds.

Kaposi sarcoma presenting as severe haemoptysis

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