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AIMS: To determine the accuracy of a novel endoluminal brush method for the diagnosis of catheter related sepsis (CRS), which is performed in situ and hence does not require line sacrifice. METHODS: 230 central venous catheters in 216 patients were examined prospectively for evidence of CRS or colonisation using an endoluminal brush method in conjunction with peripheral blood cultures. The results were compared with those obtained using methods that require line sacrifice: extraluminal sampling (Maki roll) or endoluminal sampling (modified Cleri flush) of microorganisms. RESULTS: Only 16% of 128 patients suspected clinically of having line associated infection were confirmed as having CRS. In addition, 2 of 102 patients not suspected of having line associated infection had CRS. Line colonisation was apparent in approximately twice as many catheters using the Maki roll criteria (92%) compared with either the endoluminal brush (43%) or Cleri flush (43%). Furthermore, colonised catheters sampled using the Maki roll technique yielded mixed growth twice as often as when examined by endoluminal methods (17 and 8 cases, respectively). It was rare to detect either only endoluminal (4 of 22 episodes) or extraluminal (1 of 22 episodes) microorganisms in cases of CRS. In contrast, catheters defined as being colonised most frequently (59% of episodes) yielded only significant extraluminal growth. Only one case of CRS (5%) would have been "missed" if lines yielding a negative result from endoluminal brush sampling had been left in situ. Conversely, four episodes of CRS (18%) would not have been diagnosed by relying on extraluminal sampling alone. CONCLUSIONS: Diagnosis of CRS by the endoluminal brush method can be achieved without line sacrifice and is more sensitive (95%) and specific (84%) than extraluminal sampling of the catheter tip by the Maki roll technique (82% and 66%, respectively). [ABSTRACT FROM PUBLISHER]

AIMS: To determine the accuracy of eight commercially available kits for the serological diagnosis of Helicobacter pylori infection, and hence whether a serology service could be introduced to reduce endoscopy workload. METHODS: Eighty four patients newly presenting to their general practitioners with dyspepsia were recruited. Gold standard diagnosis of H pylori infection was obtained both by a histological examination of gastroduodenal biopsy specimens and by the 14C-urea breath test (UBT). The performance of six quantitative and two qualitative enzyme linked immunosorbent assays for H pylori IgG, used according to the manufacturers' instructions, with serum samples obtained during the endoscopy visit, were compared. RESULTS: The study population had a median age of 45 years, and the prevalence of H pylori infection was 35%. With one exception, where the patient had received a course of anti-H pylori treatment between endoscopy and UBT, there was 100% concordance in the results of the two gold standard techniques. Discordant serology results were more common in patients aged > 50 years (42% of the total) than in younger patients (21%), and this was most noticeable in uninfected patients. The sensitivity of the kits was good (90-100%), but specificity was more variable (76-96%), and the rate of equivocal results was unacceptably high in some cases (0-12%). The overall accuracy of the kits ranged from 83 to 98%. Two kits in particular performed well (Pylori-Elisa II, Bio-Whitaker and Premier, Launch; qualitative) with 98% and 100% accuracy, respectively. CONCLUSIONS: In a symptomatic population with a prevalence of H pylori infection of 35%, particularly in patients aged < 50 years, some but not all serology kits may be used as a highly accurate and inexpensive alternative to the gold standard techniques. [ABSTRACT FROM PUBLISHER]

AIMS: To determine the effect of pH changes occurring in cerebrospinal fluid (CSF) after sampling on the viability of meningitis causing bacteria, and on the performance of agglutination assays used for the rapid detection of bacterial antigens. METHODS: The pH of CSF collected via lumbar puncture was measured by various methods, and the effects of the following different incubation conditions on subsequent changes were determined: air at 4 degrees C; air at room temperature (22 degrees C); air at 37 degrees C; and air with 5% CO2 at 37 degrees C. The growth/survival in pooled CSF of 15 bacterial isolates collected from 74 patients with meningitis was assessed in these incubation conditions over 24 hours. The effects of pH changes in the CSF on the sensitivity of two latex agglutination and one co-agglutination kits for detecting Haemophilus influenzae, Neisseria meningitidis groups B and C, and Streptococcus pneumoniae were determined. RESULTS: The measured pH of CSF was highly affected by the method used and particularly the time delay between patient sampling and assay. Measured pH values at the time of sampling (mean 7.5) increased rapidly within 60 seconds by about one unit. CSF pH continued to increase during incubation in all tested conditions (up to approximately pH 10), with the exception of in air with 5% CO2 at 37 degrees C where pH changes were reversible and near physiological values were attained. Bacterial survival for all species tested was poorest in CSF incubated in air at 37 degrees C and best following exposure to air with 5% CO2 at 37 degrees C. Agglutination in rapid antigen detection kits with CSF incubated in air as opposed to air with 5% CO2 generally took longer to occur and in some instances was less prominent. In one case a false negative result was obtained with CSF seeded with N meningitidis group B incubated in the former but not the latter conditions. CONCLUSIONS: CSF pH increases after patient sampling are minimised and/or mostly reversed by incubation in an atmosphere containing 5% CO2. CSF samples should ideally be placed in such an atmosphere as soon as possible after collection, and left there until laboratory processing occurs, to reduce the detrimental effects of pH stress on bacterial survival. pH increases may also reduce the likelihood of obtaining a positive result in rapid antigen detection assays. [ABSTRACT FROM PUBLISHER]

AIMS--To assess a chemiluminescent universal probe for taxonomical and epidemiological investigations of Aeromonas sp isolates. METHODS--Total DNA was extracted from 69 well characterised Aeromonas sp strains and digested with the restriction endonucleases Sma I or Pst I. Following electrophoresis, the resulting fragments were transferred to a nylon membrane where they were hybridised to a commercially available universal probe of 16S + 23S rRNA. The banding patterns (ribotypes) were made visible by enhanced chemiluminescence. RESULTS--Both restriction endonucleases produced heterogeneous ribotypes so that no allocation could be made to any of the control genospecies tested. For A hydrophila and A caviae, however, groups of strains (mostly from the same patient) could be identified by indistinguishable banding patterns. A relatively high proportion (36%) of A sobria strains were non-typable. CONCLUSIONS--Although this universal chemiluminescent probe is user friendly, it is unsuitable for taxonomical investigations of Aeromonas sp. It is useful in epidemiological studies of A hydrophila and A caviae, but is of less value for A sobria. [ABSTRACT FROM PUBLISHER]

AIMS--To examine the serological response of patients with systemic lupus erythematosus (SLE) and toxoplasma infection and to compare the blot profiles with those from immunocompetent subjects of similar immune response. METHODS--Forty serum samples from patients with SLE were tested for toxoplasma antibodies using the dye and indirect haemagglutination tests. Specific IgM was measured by mu-capture enzyme linked immunosorbent assay (ELISA). The sera were immunoblotted using antigen strips prepared from the RH strain of Toxoplasma gondii. For comparison, control blots were prepared from pooled sera from immunocompetent subjects with serological evidence of acute (pool 1), or chronic (pool 2) toxoplasma infection, or with no evidence of infection (pool 3). RESULTS--Some of the blot profiles from the patients with SLE were compatible with the corresponding serology but others showed considerable variation, particularly among the IgM blots. The blots from sera with low dye test titres suggested that the latter could be false positive results. CONCLUSIONS--Toxoplasma infection may enhance the production of autoantibodies which, when combined with the high titres characteristic of SLE, might interfere in the dye test and other serological tests. Immunoblotting could prove useful in the immunocompromised for confirming the presence of specific toxoplasma antibodies and for the staging of infection in those with positive serology. [ABSTRACT FROM PUBLISHER]

AIMS: To establish the suitability of currently available phenotypic methods for speciation of clinical Aeromonas isolates in diagnostic microbiology laboratories. METHODS: Using 62 Aeromonas spp, three schemes based on biochemical reactions were compared: a series of conventional tests; a system based on the suicide phenomenon, comprising two tubes in total; and a commercially available test, API 20 NE, augmented with a plate assay for beta haemolysin production. The whole cell and outer membrane protein (OMP) profiles of strains were examined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE), according to the results of the above schemes, to determine the intra-species homogeneity. RESULTS: Ninety per cent of strains were identified satisfactorily according to conventional criteria. For these strains, agreement was obtained using the suicide phenomenon and API schemes in 93% and 88% of cases, respectively. The three schemes concurred for 82% of strains. Whole cell protein profiles were unsuitable for comparing strains within a species. However, OMP patterns were similar for 89% of A caviae and 63% of A hydrophila. CONCLUSION: Phenospeciation of clinical Aeromonas isolates by the scheme based on the suicide phenomenon is simple to perform and accurate, and suitable for use in the diagnostic laboratory. OMP profiles are potentially useful for confirming the identity of A caviae and most A hydrophila, but not A sobria. [ABSTRACT FROM PUBLISHER]

AIMS: To determine the prevalence of Aeromonas spp in the faeces of children and the association with symptoms of gastroenteritis. METHODS: Faecal specimens (n = 1026) were cultured for Aeromonas spp using three selective media and an enrichment broth at both 30 degrees C and 37 degrees C. The isolation of Aeromonas spp was correlated with symptoms of gastroenteritis, previous antibiotic use, and environmental temperature. RESULTS: Aeromonas spp (n = 28) from 26 (2.5%) patients were recovered. Bile salt, Irgasan, and brilliant green agar was the most efficient selective culture medium. Eleven of the patients had symptoms of gastroenteritis, usually mild diarrhoea of two to three days' duration, in the absence of other recognised enteropathogens. A caviae was a particularly frequent isolate (nine out of 11 cases) in symptomatic individuals. Only one out of seven Aeromonas spp recovered by enrichment culture alone was possibly associated with symptoms of gastroenteritis. There was a close correlation between the environmental temperature and isolation of Aeromonas spp. CONCLUSIONS: Aeromonas spp and particularly A caviae may cause gastroenteritis in children, most often during warmer months of the year. Culture for these potential enteropathogens could be confined to summer and autumn months. Bile salt, Irgasan, and brilliant green selective agar, but not alkaline peptone water enrichment, is an efficient culture medium for recovering possibly clinically important isolates. [ABSTRACT FROM PUBLISHER]

The toxoplasma serological status of 50 patients with systemic lupus erythematosus (SLE) was compared with that of 50 healthy controls; high titres of toxoplasma antibody were significantly more common in the patients with SLE. These titres did not correlate with any of the routinely measured indices in SLE nor with the patients' prior treatment. A case history is used to illustrate the difficulty in diagnosing toxoplasmosis in the presence of SLE. [ABSTRACT FROM PUBLISHER]

Methodological modifications, particularly the use of different fixatives, may account for discrepancies between studies of the relation between virulence and biofilm production in vitro by isolates of coagulase negative staphylococci. The efficacy of formalin and Bouin's reagent for fixing coagulase negative staphylococcal biofilms in a microtitre tray assay was compared. The optical density of stained adherent growth by three strains was reduced by an average of 20% following fixation with 10% formaldehyde compared with Bouin's reagent. This difference seemed to be mainly because of increased background staining and blackening of the biofilm when Bouin's reagent was used. Formalin fixation was also effective at identifying early and late biofilm production in adherence growth kinetic experiments with 10 coagulase negative staphylococcal clinical isolates. [ABSTRACT FROM PUBLISHER]