Publications (15)52.79 Total impact
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Article: A simple evaluation of the AnaeroGenTM system for the growth of clinically significant anaerobic bacteria
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ABSTRACT: A novel method for the provision of an anaerobic atmosphere suitable for the growth of clinically significant anaerobic bacteria was evaluated. The AnaeroGenTM (Oxoid) was compared to an existing commercially available system based on the catalysis of internally generated hydrogen. The new system successfully facilitated the growth of a range of 50 strains of anaerobes and its overall performance compared very favourably with the established method.Letters in Applied Microbiology 06/2008; 18(1):56 - 58. · 1.62 Impact Factor -
Article: Outbreak of Clostridium histolyticum infections in injecting drug users in England and Scotland.
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ABSTRACT: Clostridial infections in injecting drug users in the United Kingdom are a relatively new phenomenon that came to light in 2000 when cases of serious illness and deaths due to Clostridium novyi were recorded. In the period December 2003 to April 2004, the Anaerobe Reference Laboratory received twelve referrals of an extremely rare isolate, Clostridium histolyticum, from cases of infection in injecting drug users submitted from nine different hospitals in England and Scotland. Molecular typing of these isolates by two different methods of pulsed-field gel electrophoresis and PCR ribotyping revealed they are all indistinguishable, indicating a common source of the infections, most probably a batch of heroin that was recently distributed across the UK.Euro surveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 10/2004; 9(9):15-6. · 6.15 Impact Factor -
Article: Antibiotic susceptibilities of Gram-positive anaerobic cocci: results of a sentinel study in England and Wales.
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ABSTRACT: A sentinel study was carried out to determine the antimicrobial susceptibilities of Gram-positive anaerobic cocci (GPAC) freshly isolated from clinical material in diagnostic laboratories in England and Wales. A total of 113 GPAC isolates consisting predominantly of current or former members of the genus Peptostreptococcus was obtained from 17 sentinel laboratories in England and one in Wales. Minimum inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by the Etest method. The agents tested were: penicillin, tetracycline, erythromycin, cefoxitin, clindamycin, chloramphenicol, imipenem, co-amoxiclav, piperacillin/tazobactam and metronidazole. MIC50 and MIC90 values for each drug-species combination were calculated whenever suitable numbers of each species were obtained. Excellent spectra of activity (0% resistance) against GPAC were seen for metronidazole, piperacillin/tazobactam, cefoxitin, imipenem and chloramphenicol. Low degrees of resistance to co-amoxiclav (3.5%), clindamycin (7.1%), penicillin (7.1%) and significant degrees of resistance to tetracycline (41.6%) and erythromycin (27.4%) were detected. Some examples of putative macrolide-lincosamide linked resistance were noted in seven (6.2%) isolates of GPAC. This study is one of the largest susceptibility studies specifically on GPAC carried out to date and the resulting data may be of value to those involved in the empirical treatment of infections involving Gram-positive anaerobic cocci.Journal of Antimicrobial Chemotherapy 09/2003; 52(2):224-8. · 5.07 Impact Factor -
Article: Heterogeneity within the gram-positive anaerobic cocci demonstrated by analysis of 16S-23S intergenic ribosomal RNA polymorphisms.
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ABSTRACT: Peptostreptococci are gram-positive, strictly anaerobic bacteria which, although regarded as members of the commensal human microflora, are also frequently isolated from sites of clinical infection. The study of this diverse group of opportunist pathogens has been hindered by an inadequate taxonomy and the lack of a valid identification scheme. Recent re-classification of the Peptostreptococcus family into five distinct genus groups has helped to clarify the situation. However, this has been on the basis of 16S rRNA sequence determinations, which are both time-consuming and expensive. The aim of the present study was to evaluate the use of PCR-amplified ribosomal DNA spacer polymorphisms for the rapid differentiation of the currently recognised taxa within the group of anaerobic gram-positive cocci. A collection comprising 19 reference strains with representatives of each of the 15 species, two close relatives and two of the well-characterised groups, together with 38 test strains was studied. All strains were identified to species group level by phenotypic means. Amplification of the 16S-23S intergenic spacer region (ISR) with universal primers produced distinct banding patterns for all the 19 reference strains and the patterns could be differentiated easily visually. However, of the 38 test strains, less than half could be speciated from ISR analysis alone. Only five groups produced correlating banding patterns for all members tested (Peptoniphilus lacrimalis, P. ivorii, Anaerococcus octavius, Peptostreptococcus anaerobius and Micromonas micros). For other species, either the type strain differed significantly from other species members (e.g., A. hydrogenalis) or there appeared to be considerable intra-species variation (e.g., A. vaginalis). Partial 16S rRNA gene sequences for the 'trisimilis' and 'betaGAL' groups showed that both are most closely related to the Anaerococcus group. This work highlights the heterogeneous nature of a number of Peptostreptococcus species and hence the need for still further revision of the taxonomy of this important group of pathogens.Journal of Medical Microbiology 12/2002; 51(11):949-57. · 2.50 Impact Factor -
Article: An outbreak of serious illness and death among injecting drug users in England during 2000.
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ABSTRACT: An outbreak of serious illness and death occurred in injecting drug users during 2000 in Scotland, Ireland and England. National and international collaboration was necessary for the investigation and management of this outbreak. In England and Wales active case-finding was initiated, coupled with standardised data collection and microbiological investigation of cases. Twenty-six definite or probable cases were identified in England between 1 April and 31 Aug. 2000; 17 of these occurred in the North. The overall case fatality was 50% (13/26). The principal apparent risk factor was a history of intramuscular or subcutaneous injection of heroin and the limited duration of the outbreak suggested that the problem might have been related to a particular supply of heroin. Clostridium novyi was isolated from two English cases. Taken in conjunction with contemporaneous microbiological and epidemiological results from Scottish and Irish cases, the probable aetiology for this outbreak was infection with C. novyi associated with both a particular supply of heroin and the method of preparation and injection used. A 'toolkit' was distributed in Sept. 2000 to all Consultants for Communicable Disease Control in England and Wales to assist them with the ongoing surveillance, investigation and management of this condition. Lessons learned have been used to produce guidance for the investigation and management of outbreaks of unexplained serious illness of possible infective aetiology.Journal of Medical Microbiology 12/2002; 51(11):978-84. · 2.50 Impact Factor -
Article: Isolation and identification of Clostridium spp. from infections associated with the injection of drugs: experiences of a microbiological investigation team.
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ABSTRACT: Pathogenic species of the genus Clostridium may contaminate the materials used in the injection of drugs and under the right conditions may cause serious or life-threatening disease. C. novyi type A was implicated in an outbreak of severe infection with high mortality in injecting drug users who injected heroin extravascularly. The isolation of such highly oxygen-sensitive clostridia from clinical material may require adherence to enhanced methods and, once isolated, commercially available anaerobe identification kits alone may not give an accurate identification. Additional phenotypic tests that are useful in recognising the main pathogenic species are described. Differentiation of C. novyi type A from C. botulinum type C in reference laboratories was based on 16S rDNA sequence data and specific neutralisation of cytopathic effects in tissue culture.Journal of Medical Microbiology 12/2002; 51(11):985-9. · 2.50 Impact Factor -
Article: Fusobacterium necrophorum infections in England and Wales 1990-2000.
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ABSTRACT: In response to a marked increase in both the number of Fusobacterium necrophorum bacteraemia reports to the PHLS Communicable Disease Surveillance Centre and the number of F. necrophorum isolates referred to the PHLS Anaerobe Reference Unit in 1999, the data from both sources on F. necrophorum infections were reviewed for the decade 1990-2000. There were 208 reports of F. necrophorum bacteraemia (average 19/year; range 14-34/year) with a peak in incidence in the late winter months; 68% were from male patients and the peak age range was 16-23 years. Of 205 referred isolates of F. necrophorum, 122 (59%) were from blood cultures and these represented 58% of the bacteraemia reports; the others were from brain and soft tissue abscesses, pleural and joint fluids, eyes, ears and lymphatic tissue. The average number of referrals was 19/year (range 9-37/year). The peak year for bacteraemia reports (34) and isolate referrals (37) was 1999; this increase was not sustained in 2000. All isolates were susceptible to metronidazole, but 2% were resistant to penicillin and 15% to erythromycin. F. necrophorum continues to be a regular but uncommon cause of bacteraemia and metastatic abscesses following an acute sore throat, especially in young, otherwise healthy adults.Journal of Medical Microbiology 04/2002; 51(3):269-72. · 2.50 Impact Factor -
Article: Identification of clinical isolates of actinomyces species by amplified 16S ribosomal DNA restriction analysis.
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ABSTRACT: Amplified 16S ribosomal DNA (rDNA) restriction analysis (ARDRA), using enzymes HaeIII and HpaII, was applied to 176 fresh and 299 stored clinical isolates of putative Actinomyces spp. referred to the Anaerobe Reference Unit of the Public Health Laboratory Service for confirmation of identity. Results were compared with ARDRA results obtained previously for reference strains and with conventional phenotypic reactions. Identities of some strains were confirmed by analysis of partial 16S rDNA sequences. Of the 475 isolates, 331 (70%) were clearly assigned to recognized Actinomyces species, including 94 isolates assigned to six recently described species. A further 52 isolates in 12 ARDRA profiles were designated as apparently resembling recognized species, and 44 isolates, in 18 novel profiles, were confirmed as members of genera other than Actinomyces. The identities of 48 isolates in nine profiles remain uncertain, and they may represent novel species of Actinomyces. For the majority of species, phenotypic results, published reactions for the species, and ARDRA profiles concurred. However, of 113 stored isolates originally identified as A. meyeri or resembling A. meyeri by phenotypic tests, only 21 were confirmed as A. meyeri by ARDRA; 63 were reassigned as A. turicensis, 7 as other recognized species, and 22 as unidentified actinomycetes. Analyses of incidence and clinical associations of Actinomyces spp. add to the currently sparse knowledge of some recently described species.Journal of Clinical Microbiology 11/2001; 39(10):3555-62. · 4.15 Impact Factor -
Article: Evaluation of a phenotypic scheme for identification of the 'butyrate-producing' Peptostreptococcus species.
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ABSTRACT: Gram-positive anaerobic cocci (GPAC) are isolated from approximately one quarter of all infections involving anaerobic bacteria. However, studies of the significance of this group of pathogens have been hindered by an inadequate taxonomy and the lack of a valid identification scheme. In the present study, a phenotypic scheme for the identification of 'butyrate-producing' GPAC based on the analysis of volatile fatty acid profiles by gas-liquid chromatography, biochemical profiles (including the use of the rapid ID 32 A commercial kit) and carbohydrate fermentation reactions, was evaluated. The identity of 68 clinical isolates of GPAC was determined by application of the scheme published by Murdoch. The scheme was found to be easy to apply and only four of the test isolates could not be readily assigned to a species or well-defined group. The species most frequently identified in the test collection were Peptostreptoccoccus vaginalis, P. tetradius and the betaGAL group. A large number of strains was assigned to the heterogeneous 'prevotii/tetradius' group. Some species regarded as being restricted to particular clinical sites were shown to be more widespread than previously thought. The clinical source of the isolates did not show any consistent correlation with species identity.Journal of Medical Microbiology 09/2000; 49(8):747-51. · 2.50 Impact Factor -
Article: Development of amplified 16S ribosomal DNA restriction analysis for identification of Actinomyces species and comparison with pyrolysis-mass spectrometry and conventional biochemical tests.
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ABSTRACT: Identification of Actinomyces spp. by conventional phenotypic methods is notoriously difficult and unreliable. Recently, the application of chemotaxonomic and molecular methods has clarified the taxonomy of the group and has led to the recognition of several new species. A practical and discriminatory identification method is now needed for routine identification of clinical isolates. Amplified 16S ribosomal DNA restriction analysis (ARDRA) was applied to reference strains (n = 27) and clinical isolates (n = 36) of Actinomyces spp. and other gram-positive rods. Clinical strains were identified initially to the species level by conventional biochemical tests. However, given the low degree of confidence in conventional methods, the findings obtained by ARDRA were also compared with those obtained by pyrolysis-mass spectrometry. The ARDRA profiles generated by the combination of HaeIII and HpaII endonuclease digestion differentiated all reference strains to the species or subspecies level. The profiles correlated well with the findings obtained by pyrolysis-mass spectrometry and by conventional tests and enabled the identification of 31 of 36 clinical isolates to the species level. ARDRA was shown to be a simple, rapid, cost-effective, and highly discriminatory method for routine identification of Actinomyces spp. of clinical origin.Journal of Clinical Microbiology 08/1999; 37(7):2255-61. · 4.15 Impact Factor -
Article: A comparative study of Fusobacterium necrophorum strains from human and animal sources by phenotypic reactions, pyrolysis mass spectrometry and SDS-PAGE.
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ABSTRACT: Fusobacterium necrophorum strains from human infection (21) were compared with strains from animals (17 biotype A, 2 biotype AB, 4 biotype B, 1 biotype unknown), and the type strain NCTC 10575 in conventional tests reaction patterns (CTRPs), SDS-PAGE and pyrolysis mass spectrometry (PMS). Classifications from the three approaches showed one major consensus group comprising all human strains, and another comprising animal biotype A strains. Animal biotype B strains and one animal strain, designated with some doubt to biotype A, were outliers of the consensus 'human strain' group. Again, animal biotype AB strains were outliers of the consensus 'animal biotype A group', as was the type strain, which was clearly atypical in conventional tests and PMS. Colonial and microscopic characters showed good discrimination between the major consensus groups. However, only haemagglutination and the API-ZYM leucine arylamidase of the biochemical tests discriminated well between these groups. The 'animal biotype A group' clearly corresponds to F. necrophorum subsp. necrophorum, but synonymy of F. necrophorum subsp. funduliforme with the group of human strains was less certain. The latter subspecies was described solely on the basis of animal strains, all of biotype B, but each of four animal biotype B strains in this study was an outlier of the 'human strain group' in one or more of the characterisation approaches. Strains of F. necrophorum causing human infection were clearly distinct from the biotype A strains commonly found in animal infection. This has implications for the validity of animal models of human necrobacillosis. In view of these differences, it would be useful to have a validated designation for strains causing human infection. However, it would be premature to assume that the definition of F. necrophorum subsp. funduliforme encompasses the human strains in the absence of confirmatory DNA-homology and 16S rRNA-sequencing studies.Journal of Medical Microbiology 11/1997; 46(10):865-71. · 2.50 Impact Factor -
Article: A rapid test for the presumptive identification of Clostridium perfringens.
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ABSTRACT: A novel rapid method for the identification of colonies of Clostridium perfringens (key iD Lab M Ltd. Bury, UK) was evaluated. The method consists of a test strip containing substrates for pre-formed enzymes selected for optimum differentiation of C. perfringens from other clostridia. One hundred and forty-six strains of clostridia were tested using the key iD strip. The strip successfully confirmed the identity of all 73 strains of C. perfringens tested, and differentiated these from 73 strains of 20 other clostridial species. C. absonum and C. baratii, spedes which are very similar to C. perfringens, could also be differentiated by this method. The key iD strip is recommended for laboratories as a rapid alternative to more conventional tests for presumptive identification of C. perfringens.Anaerobe 07/1995; 1(3):157-9. · 2.41 Impact Factor -
Article: Propionibacterium propionicum and infections of the lacrimal apparatus.
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ABSTRACT: Analysis of the clinical details associated with 26 referred isolates of Propionibacterium propionicum revealed the marked propensity of this anaerobe to be involved with infections of the lacrimal apparatus; 18 (69%) of the 26 referred isolates were from cases of canaliculitis in which this organism was regarded as the significant pathogen. Further analysis of data showed a significant correlation with the sex of the patient. Of the 18 cases of canaliculitis, the sex of the patient was reported in 16; 14 (88%) of these 16 patients were females (P < .005). The age of 13 of the 18 patients with canaliculitis was known (mean, 61.6 years; range, < 1-80 years); it appears from these cases that P. propionicum lacrimal infections are more common in later life. None of the referred isolates were identified as Actinomyces species. Despite the fact that infection of the lacrimal apparatus is known as ocular actinomycosis, it appears that P. propionicum is more frequently associated with the condition than are true Actinomyces species.Clinical Infectious Diseases 12/1993; 17(5):892-3. · 9.15 Impact Factor -
Article: Artefactual resistance to metronidazole in anaerobes of the Bacteroides fragilis group.
Journal of Antimicrobial Chemotherapy 11/1992; 30(4):553-4. · 5.07 Impact Factor -
Article: Antibiotic susceptibilities of Gram-positive anaerobic cocci: results of a sentinel study in England and Wales
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1993–2008
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University of Wales
Cardiff, WLS, United Kingdom
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