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Biomedical subjects

C S Goodwin

Publications and source records attributed to C S Goodwin.

At least 37 records · Page 2Linked to original sources

Cellular fatty acid composition of Campylobacter pylori from primates and ferrets compared with those of other campylobacters.

The cellular fatty acid profiles of newly described campylobacters were determined on a polar, capillary column. Six isolates of the gastric spiral organism, Campylobacter pylori subsp. mustelae, from ferrets from Australia, England, and the United States were all found to have a similar fatty acid profile which was different from that of C. pylori from humans; C. pylori subsp. mustelae did not have 3-hydroxyoctadecanoic acid (3-OH C18:0) and had much less tetradecanoic acid (C14:0) and much more hexadecanoic acid (C16:0). Inasmuch as Lambert et al. (M.A. Lambert, C.M. Patton, T.J. Barrett, and C.W. Moss, J. Clin. Microbiol. 25:706-713, 1987) have proposed that campylobacters can be grouped by cellular fatty acid composition, we propose this organism should be in a new gas-liquid chromatography (GLC) group, group J. Seven isolates of gastric spiral organisms from macaque monkeys and baboons, including three from Macaca nemestrina, and one isolate from a pig were found to have fatty acid profiles very similar to that of C. pylori; but a second type of organism (type B) from M. nemestrina had a unique profile without 19-carbon cyclopropane fatty acid (C19:0 cyc) but with 3-hydroxy tetradecanoic acid (OH C14:0), which is not present in other gastric spiral bacteria. We propose that this organism (nemestrina type B) should be in a new GLC group, group K. The cellular fatty acid profile of seven isolates of C. jejuni subsp. doylei was found to be similar to that for C. jejuni, but with possibly significant differences in that the former did not have 3-OH C14:0 but did have 3-hydroxyhexadecanoic acid (3-OH C16:0) and had more C14:0 than did C. jejuni. Two strains of urease-positive thermophilic campylobacters were found to have a profile similar to that of "C. cinaedi" and thus should be included with them in GLC group D. We confirm that C. sputorum has a unique cellular fatty acid composition and suggest that it should be in a new group, group H.

Animals↗

Restriction endonuclease analysis of the genome of Campylobacter pylori with a rapid extraction method: evidence for considerable genomic variation.

We developed a rapid extraction method to analyze the chromosomal DNA of 84 isolates of Campylobacter pylori (formerly Campylobacter pyloridis) from 70 individuals. Only three of the nine endonucleases tested gave satisfactory digestions: HindIII, EcoRI, and SacI. The latter two produced mostly larger bands, whereas HindIII produced smaller bands, which allowed clearer comparisons between isolates. The isolates from 69 Australian subjects and one from England each had a unique profile. Isolates from a husband and wife were different, as were those from a brother and sister. In pairs of isolates from 11 individuals, the second isolate was markedly different in six subjects. The profile changes were not associated with changes in antibiotic susceptibility or with loss of catalase or urease activity, which can occur during storage of C. pylori. These restriction endonuclease profiles suggest considerable subspecies variation in C. pylori. Plasmid bands were found in undigested DNA from 40 of the 84 C. pylori isolates.

Campylobacter↗

The use of in-vitro sensitivity testing to predict clinical response of recurrent herpes simplex to suppressive oral acyclovir.

Twenty-six pre-treatment isolates of herpes simplex virus from 20 immunocompetent patients with frequently recurring mucocutaneous herpes were tested for in-vitro sensitivity by a plaque reduction assay. When correlated with the occurrence of breakthrough attacks during subsequent courses of suppressive treatment with oral acyclovir the mean ID50, ID90 and ID99 were all found to be significantly higher for isolates associated with breakthroughs. However, cut-off values could only be set for the ID90 and ID99 values. An ID99 less than 0.75 mg/l was found in 17/21 (81%) of isolates not associated with breakthrough attacks, but none of five isolates associated with breakthroughs. The corresponding findings for an ID90 less than 0.5 mg/l were 17/21 (81%) without breakthroughs and 1/5 with breakthroughs. It is suggested that the ID90 and ID99 are better predictors of the clinical response to suppressive oral acyclovir than is the ID50. Possibly this is because they better reflect the presence of viral strains with reduced sensitivity which may be responsible for breakthrough attacks.

Acyclovir↗

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).

Anti-Ulcer Agents↗

Enzyme-linked immunosorbent assay for Campylobacter pyloridis: correlation with presence of C. pyloridis in the gastric mucosa.

Antibody to Campylobacter pyloridis was measured by ELISA in the sera of 160 patients from whom gastric biopsy specimens were also obtained. The antigen was an acid-glycine extract of C. pyloridis, and titers ranged from 80 to 22,000 ELISA units (EU). Of 117 patients in whom C. pyloridis was detected microbiologically or histologically, 87 (74%) had a titer greater than or equal to 300 EU, and only one had a titer less than 150 EU. Of 43 patients in whom C. pyloridis was not detected, only two (5%) had a titer greater than 300 EU. Thus, for a titer of 300 EU the ELISA test had a specificity of 97% and a sensitivity of 81%. At 150 EU the specificity was 78%, and the sensitivity was 99%. Histological diagnosis of active chronic gastritis was associated with a high median ELISA titer (485 E), chronic gastritis with a much lower titer (150 EU), and normal histology with a titer of 110 EU. Discriminating use of this serological test could be of assistance to detect C. pyloridis in the gastric mucosa.

Adult↗

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.

Blood Bactericidal Activity↗

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.

Amoxicillin↗

Rapid urease test in the management of Campylobacter pyloridis-associated gastritis.

Campylobacter pyloridis colonization of the stomach may be an etiological factor in gastritis and peptic ulceration. Campylobacter pyloridis produces large amounts of urease, and the presence of this enzyme in gastric mucosa usually indicates infection with the organism. In this paper we describe the use of a rapid urease test (CLOtest) to detect C. pyloridis infection in gastric mucosal biopsies. In 141 consecutive endoscopy cases, antral biopsies were taken for culture and histology, and an extra biopsy was inserted into the CLOtest gel. There were 79 patients infected with C. pyloridis, 78 of whom were detected by CLOtest: 75% were positive at 20 min, 92% at 3 h, and 98% at 24 h. There were no false positive results. Eighteen infected patients were rebiopsied after a course of amoxycillin and bismuth subcitrate. Active chronic gastritis resolved in eight of nine who were cleared of the organism, but histological gastritis was unchanged in nine patients who were still infected. CLOtest is a simple, sensitive, and highly specific test that enables the endoscopist to diagnose C. pyloridis infection in the endoscopy room. A negative test after antibiotic therapy correlates with clearance of the bacteria and healing of active gastritis.

Amoxicillin↗

The minimum inhibitory and bactericidal concentrations of antibiotics and anti-ulcer agents against Campylobacter pyloridis.

The minimum inhibitory and bactericidal concentrations of twenty-two antibiotics, in liquid and solid media, and three anti-peptic ulcer drugs in liquid media were determined against twenty isolates of Campylobacter pyloridis. Camp. pyloridis was very susceptible to most antibiotics, more so than Camp. jejuni and Camp. fetus, but was resistant to nalidixic acid. The MIC90 of cimetidine against Camp. pyloridis was 512 mg/l, and of ranitidine was 6400 mg/l. The difference in susceptibility patterns between Camp. pyloridis and other campylobacters may indicate that Camp. pyloridis is not a member of the Campylobacter genus.

Anti-Bacterial Agents↗

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.

Amoxicillin↗

Control of methicillin-resistant Staphylococcus aureus (MRSA) in an Australian metropolitan teaching hospital complex.

In April 1982, a patient infected with methicillin-resistant Staphylococcus aureus (MRSA) was transferred to the Royal Perth Hospital from the Royal Darwin Hospital. Within three months, 19 patients and four staff members had become infected or colonized with MRSA. The outbreak was terminated only after all colonized inpatients were transferred to a separate isolation unit. After the outbreak, all new patients and new employees who had been in hospitals outside Western Australia in the previous 12 months were screened. From June 1, 1982, to June 30, 1984, 28 of the 649 patients (4.3%) screened on admission to the Royal Perth Hospital were found to be harbouring MRSA. During the same period only one of the 468 persons (0.2%) screened on application for employment at the Hospital was found to be colonized with MRSA. Since the policy of screening new patients and staff from hospitals outside Western Australia was introduced, no serious outbreak of MRSA has occurred.

Adolescent↗

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.

Base Composition↗

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.

Adult↗