Computer printing and filing of microbiology reports. 2. Evaluation and comparison with a manual system, and comparison of two manual systems.

A manual system of microbiology reporting with a National Cash Register (NCR) form with printed names of bacteria and antiboitics required less time to compose reports than a previous manual system that involved rubber stamps and handwriting on plain report sheets. The NCR report cost 10-28 pence and, compared with a computer system, it had the advantages of simplicity and familarity, and reports were not delayed by machine breakdown, operator error, or data being incorrectly submitted. A computer reporting system for microbiology resulted in more accurate reports costing 17-97 pence each, faster and more accurate filing and recall of reports, and a greater range of analyses of reports that was valued particularly by the control-of-infection staff. Composition of computer-readable reports by technicians on Port-a-punch cards took longer than composing NCR reports. Enquiries for past results were more quickly answered from computer printouts of reports and a day book in alphabetical order.

Computer printing and filing of microbiology reports. 1. Description of the system.

From March 1974 all reports from this microbiology department have been computer printed and filed. The system was designed to include every medically important microorganism and test. Technicians at the laboratory bench made their results computer-readable using Port-a-punch cards, and specimen details were recorded on paper-tape, allowing the full description of each specimen to appear on the report. A summary form of each microbiology phrase enabled copies of reports to be printed on wide paper with 12 to 18 reports per sheet; such copies, in alphabetical order for one day, and cumulatively for one week were used by staff answering enquiries to the office. This format could also be used for printing allthe reports for one patient. Retrieval of results from the files was easily performed and was useful to medical and laboratory staff and for control-of-infection purposes. The system was written in COBOL and was designed to be as cost-effective as possible without sacrificing accuracy; the cost of a report and its filing was 17-97 pence.

Detection of bacteriuria in women attending local authority antenatal clinics using the dip-inoculum transport medium spoon method.

Four hundred and seventy-eight pregnant women attending local authority clinics in Portsmouth were screened for bacteriuria using the dip-inoculum transport medium (DITM) spoon method. The detection of asymptomatic bacteriuria in 5% of the patients with a very low proportion of equivocal results (0.83%) suggests that this is an efficient method; and large numbers of urine specimens could be sampled with relatively little work for the laboratory. A cystine-MacConkey medium was devised for incorporation in the spoons. General practitioners treated the women with bacteriuria, and remained responsible for home delivery and postpartum examinations. The possibility of successful cooperation between non-hospital clinics, a bacteriological laboratory, and general practitioners is demonstrated.

Campylobacter pyloridis, gastritis, and peptic ulceration.

Campylobacter pyloridis is a spiral bacterium which was seen by histopathologists several years before it was cultured in 1982 in Perth, Western Australia. It has unique cellular fatty acids, predominantly tetradecanoic acid and cis-11, 12 methylene octadecanoic acid. It also has a unique ultrastructure which is different from that of other campylobacters. C pyloridis possesses a powerful urease enzyme and produces large amounts of extracellular catalase. Both these features may be important virulence factors, allowing it to occupy a protected niche in the stomach below the mucus layer but above the gastric mucosa. Specific lesions are found in the gastric mucosa, and ultrastructural studies show the presence of adherence pedestals identical with those found with enteropathogenic Escherichia coli of the intestine. Histological examination of gastric biopsy tissue has shown that C pyloridis is strongly associated with active chronic gastritis, when polymorphonuclear leucocytes are present, and is not found on normal mucosa except when a biopsy specimen from elsewhere in the stomach shows active chronic gastritis. When patients with symptoms caused by gastritis are identified dual antibacterial treatment, combining the action of bismuth in the stomach with a systemic antibiotic, can eradicate C pyloridis, with remission of symptoms and restoration of normal epithelial morphology. Most peptic ulcers relapse after modern acid reducing treatment, and antibacterial treatment may be beneficial in preventing relapse.

Prevention of nitroimidazole resistance in Campylobacter pylori by coadministration of colloidal bismuth subcitrate: clinical and in vitro studies.

One hundred patients with duodenal ulceration and Campylobacter pylori in their stomach were entered into a double blind placebo controlled prospective study. Treatment schedules were cimetidine and placebo, or cimetidine and tinidazole, or colloidal bismuth subcitrate (CBS) and placebo, or CBS and tinidazole. Seventeen per cent of isolates of C pylori obtained at the first endoscopy were resistant to tinidazole and 70% of the second isolates from patients given cimetidine and tinidazole became tinidazole resistant. Suspensions of nitroimidazole sensitive cultures of C pylori showed that three of 22 isolates had a nitroimidazole resistant subpopulation. In patients who healed and remained free of C pylori after treatment ulcers recurred less often than in patients who healed but retained C pylori (23% v 73% over 12 months, p less than 0.001).

Evaluation of cultural techniques for isolating Campylobacter pyloridis from endoscopic biopsies of gastric mucosa.

One hundred and three gastroscopic biopsies from 80 patients were cultured for Campylobacter pyloridis and studied histologically. Active chronic gastritis, as shown by the presence of polymorphonuclear leucocytes, was diagnosed in 51 biopsies and C pyloridis was found in 47. Sixteen gastric biopsies showed normal histology (no inflammation); C pyloridis was detected in only one of these, and a second biopsy taken from this patient at the same time showed active gastritis. Biopsies could be kept at 4 degrees C for five hours without loss of viability of C pyloridis. An inoculum made by grinding the biopsy in a ground glass grinder consistently gave a much heavier growth of C pyloridis than one made by mincing the specimen. The campylobacter supplement ferrous sulphate, sodium metabisulphite, sodium pyruvate (FBP) (Oxoid) was inhibitory for some isolates; the inhibitory component was found to be sodium metabisulphite. Contaminants, but not C pyloridis, were inhibited by the incorporation of vancomycin 6 mg/l, nalidixic acid 20 mg/l, and amphotericin 2 mg/l, but higher concentrations inhibited C pyloridis. Undried plates kept in a plastic container at room temperature for up to two weeks were as satisfactory as freshly poured plates for the isolation of C pyloridis.

Interaction of Campylobacter pyloridis with human immune defence mechanisms.

The in-vitro susceptibility to host immune defence mechanisms of Campylobacter pyloridis was investigated. C. pyloridis was sensitive to antibody-dependent complement-mediated bactericidal activity of serum. The bacteria were phagocytosed and efficiently killed by polymorphonuclear neutrophils in the presence of serum opsonins. Serum opsonin depletion studies indicated that an intact classical complement pathway was required for optimal phagocytic killing.

Hydrophobic characterisation of Helicobacter (Campylobacter) pylori.

Cell-surface hydrophobicity of Helicobacter (formerly Campylobacter) pylori was tested by aqueous two-phase partitioning and hydrophobic interaction chromatography. The hydrophobicity of H. pylori greatly exceeded that of Campylobacter fetus subsp. fetus, C. jejuni and Bacillus subtilis. A partition coefficient (PC) of hydrophobicity in the two-phase system was determined for H. pylori. PC was dependent on pH and the PC value was increased by greater than 20-fold at pH 2.5. Lithium cations increased PC, indicating a net negative surface charge. The presence of urea prevented the relative loss of hydrophobicity at raised pH. Exposure of H. pylori to proteolytic enzymes reduced the ability of the bacteria to adhere to human polymorphonuclear neutrophils (PMN). These findings suggest that H. pylori possesses protein-associated hydrophobic factors that are responsible for the non-opsonic adherence to PMN cell membranes.

Response of Campylobacter pyloridis to antibiotics, bismuth and an acid-reducing agent in vitro--an ultrastructural study.

Campylobacter pyloridis was cultured for maximal growth in liquid medium, and effects of exposure to various beta-lactam and macrolide antibiotics, metronidazole, tripotassium dicitrato bismuthane (TDB) and cimetidine were monitored by transmission electronmicroscopy after periods of exposure up to 24 h. With amoxycillin and benzylpenicillin (0.12-1 mg/L) and cephalexin (2 mg/L) the normal bacilliform morphology was replaced by bulging and dumb-bell-like profiles showing cell-wall blebbing and vesiculation, and eventually by swollen forms with incomplete cell walls undergoing lysis. These changes developed progressively between 2 h and 24 h and were accelerated at the higher antibiotic concentrations. Erythromycin and clindamycin caused central clearing, ribosomal coagulation and impaired cross-wall formation. There were no gross structural changes in the presence of metronidazole (4 mg/L), TDB (1000 and 2400 mg/L) or cimetidine (1000 and 2000 mg/L); but with TDB focal accumulation of particulate bismuth complex was detected under the cell wall, affecting nearly all organisms by 24 h. In parallel viability tests, metronidazole and TDB both showed bactericidal activity, but cimetidine did not. These findings support the clinical experience that favours combination therapy with bismuth plus an appropriate systemic antibiotic as the regimen of choice for effective clearance of the organisms in C. pyloridis-associated gastritis.

Unusual cellular fatty acids and distinctive ultrastructure in a new spiral bacterium (Campylobacter pyloridis) from the human gastric mucosa.

Spiral bacteria, named Campylobacter pyloridis, were obtained from endoscopic biopsies of the gastric antrum of 14 patients with active chronic gastritis. Methyl esters of their cellular fatty acids were prepared by acid-catalysed transmethylation of whole cells. Their major fatty acids were tetradecanoic acid (14:0) and cis-9,10-methyleneoctadecanoic acid (19:0 delta), with a very small amount of hexadecanoic acid (16:0). This is markedly different from the fatty acids of other Campylobacter sp. whose major fatty acids are hexadecanoic, octadecenoic (18:1) and hexadecenoic acids (16:1). This is also different from other enterobacteria. Thin-section electronmicroscopy of gastric mucosal biopsies, and negative staining of cultured C. pyloridis, revealed features that differ from those of other campylobacters so far studied. C. pyloridis has a smooth not a rugose surface and multiple unipolar flagella of the sheathed type, each with a terminal bulb. Flagellar sheaths were in continuity with the unit membrane of the outer cell wall. The proposed species C. pyloridis does not belong among the spirochaetes and its DNA composition is incompatible with membership of the genera Spirillum or Vibrio but is compatible with Campylobacter. Thus C. pyloridis is either an atypical member of the genus Campylobacter, the limits of which may have to be redefined to accommodate the new species, or a representative of a new genus.

Soluble and cell-associated haemagglutinins of Helicobacter (Campylobacter) pylori.

Some plate-grown strains of Helicobacter (Campylobacter) pylori that were harvested into phosphate-buffered saline and left for 1 h released soluble haemagglutinins. These caused high-titre agglutination of human and guinea-pig erythrocytes, whereas chicken, sheep and bovine erythrocytes were agglutinated at various titres. Six of 10 strains which had been subcultured repeatedly did not possess soluble haemagglutinins. Slide agglutination of bacterial suspensions demarcated the strains into two groups; Group 1 gave strong agglutination with most types of erythrocyte, Group 2 did not. By microtitration assay, all Group-1 strains but only two Group-2 strains produced a soluble haemagglutinin. Cell-associated haemagglutinins were found by microtitration assay in all strains of H. pylori, but higher titres were found within Group-1 strains. The supernates of broth-grown, shaken cultures also showed the presence of soluble haemagglutinins, with higher titres for recently isolated strains. Pre-treatment of human erythrocytes with neuraminidase from Arthrobacter ureafaciens and Clostridium perfringens abolished haemagglutination by the soluble, but not by the cell-associated haemagglutinin. The soluble haemagglutinin was inhibited by sialoproteins containing predominantly the N-acetylneuraminyl (2-3) galactopyranosyl [NeuAc(2-3)Gal] structure, fetuin, glycophorin and bovine N-acetylneuraminyl-lactose (NeuAc-Lac). Transferrin and human NeuAc-Lac, which contain predominantly the N-acetylneuraminyl (2-6) galactopyranosyl [NeuAc(2-6)Gal] structure were not inhibitory. However, bovine submaxillary mucin (BSM) was strongly inhibitory; it contains several structures with sialic acid linked 2-6 to oligosaccharides. These results suggest that the soluble haemagglutinin recognises a NeuAc(2-3)Gal structure, but has high affinity for another, as yet undetermined, sialic acid-containing structure.

Influence of soluble haemagglutinins on adherence of Helicobacter pylori to HEp-2 cells.

In a study of six laboratory strains of Helicobacter pylori, two different modes of bacterial adherence to HEp-2 cells were found. Electronmicroscopy revealed that strains known to possess soluble haemagglutinin adhered intimately to the cell surfaces, with cupping of the plasma membrane and coalescence of glycocalyces at sites of attachment. Strains of H. pylori without soluble haemagglutinin also attached, but did not induce membrane cupping or show glycocalyx fusion. Light microscopy did not distinguish between these patterns of adherence. Bacterial attachment was unaffected by pre-treatment of HEp-2 cells with neuraminidase. Exposure of the bacteria to trypsin or to colloidal bismuth subcitrate (CBS) before being added to HEp-2 cells markedly impaired bacterial adherence. This effect of CBS may contribute to the known efficacy of bismuth therapy in patients with H. pylori-related gastritis.

O antigen loss by semi-rough E. coli causing recurrent urinary infections, analysed by gel column filtration and gas-liquid chromatography.

The surface polysaccharides of Escherichia coli isolated from 6 patients with recurrent urinary infection were studied serologically and chemically. In 4 patients multiple isolates were obtained. The first isolate from each of these patients was a smooth strain which could be serotyped with O antisera. The second isolates from 3 of these patients, obtained at intervals of 1-6 wk, were semi-rough strains. They could not be serotyped after culture on nutrient agar but could be serotyped after subculture on blood agar. In each patient the serotype remained the same. Gel column filtration of the polysaccharides, and gas-liquid chromatography (GLC) of the trimethyl-silylated sugars showed that smooth strains carried a preponderance of O-specific carbohydrate with little core carbohydrate. The semi-rough strains had lost nearly all their O-specific carbohydrate. The change from smooth to semi-rough involved the progressive loss of full length O-specific side-chains rather than a widespread 'shortening' of these side-chains. In patients chronically infected with the same strain of E. coli it has been shown that GLC analysis of the carbohydrates of different isolates of the same strain in one patient will vary because often the strain will undergo a smooth to semi-rough or rough variation. This variation indicates that GLC analysis of extracted carbohydrates would often not be able to determine whether multiple isolates of E. coli from one patient were the same or different strains.

The association of bacteriuria and reduced serum pyridoxal concentrations in patients with diabetes mellitus.

Of 1017 patients admitted to the Royal Perth Hospital Diabetic Survey 142 were found to have significant bacteriuria. In these bacteriuric patients serum pyridoxal concentrations were significantly reduced (P = less than 0.001) when compared with 142 diabetic patients matched for age (+/- 5 years) and sex but without infection of the urinary tract. Measurements were repeated up to 6 mth after antibacterial treatment and serum pyridoxal concentrations were still low. Pyridoxal has a role in immunological competence, and it is possible that the increased incidence of urinary tract infection in patients with diabetes reflects impaired immunological competence due to pyridoxal deficiency.

From authorship to contributorship. Promoting integrity in research publication.

Shared authorship in nursing research presents practical and ethical dilemmas and does not effectively capture individual research participation and accountability. This study, which defined author contributions and practices in multiauthored nursing research, contributed to a better understanding of contemporary author participation and the inherent challenges faced by nurse scholars in determining authorship credit. A method of "contributorship" is proposed which would delineate individual contributions to the research project while maintaining professional integrity, scientific accountability, and scholarly recognition.

Beta-lactamase resistance of cephazolin and other cephalosporins.

The turbidities of cultures of bacterial were monitored continuously at 37 degrees C. in a biophotometer. In the early phase of logarithmic growth, at approximately 2 X 10(7) organisms per ml., antibiotic was added. A strain of Escherichia coli (E. coli) that was ampicillim-resistant, but cephaloridine-sensitive, produced beta-lactamase rapidly as shown by the breakdown of a chromogenic cephalosporin. The E. coli was lysed by cephaloridine 15 minutes after the addition of the antibiotic, but, even with a concentration 8-fold greater than the MIC, after 3.5 hours the antibiotic was not detectable in the culture medium and the strain had recommenced logarithmic growth. In the presence of a concentration of cephazolin 4-fold greater than the MIC the E. coli lysed after 30 minutes and did not recommence growth 6 hours, indicating much slower destruction of the antibiotic, presumably due to the greater beta-lactamase resistance of cephazolin. Similar results were obtained with other E. coli and a strain of Klebsiella pneumoniae.