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Biomedical subjects

I Phillips

Publications and source records attributed to I Phillips.

At least 145 records · Page 8Linked to original sources
PubMed1989

The prevention of infection with Staphylococcus aureus in continuous ambulatory peritoneal dialysis.

We describe the control of wound infection with Staphylococcus aureus in patients undergoing continuous ambulatory peritoneal dialysis at St. Thomas' Hospital. Forty-nine percent of 61 catheters inserted in 1985 and 1986 became infected, and the majority of these infections were acquired in hospital. Infection was impossible to eradicate and was frequently associated with the subsequent development of S. aureus peritonitis, which was the most important cause of catheter loss. Strict adherence to aseptic techniques for catheter insertion and care, combined with eradication of S. aureus carriage, reduced the infection rate to 12% for the 50 catheters inserted in 1987, abolished hospital-acquired infection and reduced the S. aureus peritonitis rate tenfold, without the use of prophylactic antibiotics. S. aureus infection is a serious but avoidable complication of continuous ambulatory peritoneal dialysis.

Anti-Infective Agents, Local↗
PubMed1989

Mechanisms of gentamicin resistance in gram-negative bacilli in Riyadh, Kingdom of Saudi Arabia.

A survey was undertaken of the prevalence and mechanisms of gentamicin resistance in Gram-negative bacilli in Riyadh. Gentamicin resistance, as assessed by the Stokes method, occurred in less than 2% of isolates of Escherichia coli, about 10-25% of most other enterobacteria, about 40% of Acinetobacter spp. and about 25% of Pseudomonas aeruginosa. This finding of relatively low rates of gentamicin in Enterobacteriaceae was surprising in view of the unregulated use of antibiotics until recent years. AAD(2'') was by far the most commonly detected aminoglycoside-modifying enzyme in the enterobacteria. However Providencia spp. always produced AAC(2') and there was an association between Serratia spp and AAC(6'). Enzymes were less frequently detected in Acinetobacter spp. and Pseudomonas spp. AAD(2'') was also the most common enzyme in Pseudomonas spp. but was never found in Acinetobacter spp. Non-enzymatic resistance played an insignificant role in the resistance of Enterobacteriaceae in Riyadh, but may be more important in Pseudomonas spp.

Bacterial Infections↗
PubMed1989

Comparative in-vitro activity of meropenem on clinical isolates from the United Kingdom.

MICs of meropenem were determined for a wide range of common bacteria of clinical importance. For Enterobacteriaceae, Aeromonas spp., Haemophilus influenzae, Branhamella catarrhalis, Neisseria gonorrhoeae, Gardnerella vaginalis, Campylobacter coli/jejuni, beta-haemolytic streptococci and anaerobes other than Clostridium difficile, MICs were almost always within the range 0.002-0.5 mg/l. The activity of meropenem for these organisms was always greater than that of imipenem and piperacillin, and was similar to that of ceftazidime and cefotaxime except that strains resistant to these latter, and to piperacillin, were usually sensitive to imipenem and meropenem. Meropenem was also active against most non-fermentative Gram-negative bacilli, with MICs in the range 0.12-4 mg/l but Pseudomonas (Xanthomonas) maltophilia was often resistant, as it was to all the other drugs tested. Staphylococci, Strreptococcus pneumoniae and other alpha-haemolytic streptococci were usually more sensitive to imipenem than to meropenem, but even methicillin-resistant staphylococci were sensitive to both drugs (MICs less than 4 mg/l). Enterococci were also less sensitive to meropenem than to imipenem, and Enterococcus faecium was invariably highly resistant to all the drugs tested except ciprofloxacin, which had marginal activity. Results for Ps. maltophilia and Haem. influenzae were affected by media used for sensitivity testing.

Bacteria↗
PubMed1989

A qualitative and quantitative study of the cellular fatty acids of 'Streptococcus milleri' with capillary gas chromatography.

Fatty acid analysis was done with GC and GC-MS on 21 strains of 'Streptococcus milleri', representative of the various proposed species. Although no qualitative differences were found in the fatty acid profiles, discriminant analysis of the quantitative data revealed three groups. Streptococcus anginosus and Streptococcus constellatus were indistinguishable but separated from the other two groups which comprised Streptococcus intermedius, with a wide fermentation pattern and Streptococcus intermedius with a narrow fermentation pattern. Three of the strains could be distinguished from the others by a 'fingerprint' of a particularly prominent fatty acid peak. The results support the suggestion that there is more than one species in this group of organisms and that the technique might be of value in epidemiological investigations of 'S. milleri'.

Fatty Acids↗
PubMed1989

A physiological classification of viridans streptococci by use of the API-20STREP system.

Physiological reactions of viridans streptococci were examined by the API-20STREP system and a selection of conventional tests. Cluster analysis of these results produced a classification similar to a taxonomic scheme based on that of Colman and Williams. The organisms could be divided into the six recognised species--Streptococcus mutans, S. bovis, S. mitior, S. sanguis, S. salivarius and S. milleri. Analysis confirmed that S. mitior and S. sanguis can be distinguished in the API-20STREP test by hydrolysis of arginine but not by dextran production. Although S. mutans, S. mitior and S. sanguis can be divided into two further subgroups, the taxonomic significance of this is unclear. With this means of classification, most organisms could be identified easily by a small number of tests. API-20STREP is convenient for performing physiological tests on viridans streptococci, but the information provided by the manufacturers in regard to identification and nomenclature is in need of revision.

Bacteriological Techniques↗
PubMed1989

Identification of viridans streptococci by pyrolysis-gas chromatography.

An isothermal method of pyrolysis-gas chromatography (Py-GC) was used for the identification of viridans streptococci. Pyrograms from 104 reference strains were subjected to a discriminant analysis to produce classification coefficients for the identification of 74 test organisms. Five groups representing recognised species were discriminated but Streptococcus milleri strains could not be distinguished from S. sanguis. If S. milleri and S. sanguis are regarded as a single pyrogroup, only three strains out of 74 were incorrectly identified by Py-GC. A multidimensional scaling analysis of the Py-GC data produced a similar species grouping, but this statistical method was less satisfactory for pyrogram data than discriminant analysis. While Py-GC was moderately successful for the identification of viridans streptococci, this study indicated that the technique has limited use in diagnostic medical microbiology because it is time-consuming and lacks flexibility.

Chromatography, Gas↗
PubMed1989

The evaluation of a typing scheme for coagulase-negative staphylococci suitable for epidemiological studies.

A typing scheme was devised for an epidemiological study of infection with coagulase-negative staphylococci in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). The scheme was constructed in four stages suitable for the screening of large numbers of isolates: antibiogram, biotype, phage type, and plasmid profile. The discrimination and reproducibility of the scheme was established by the examination of 50 isolates from 33 consecutive episodes of peritonitis affecting 18 patients. The discrimination of the scheme was 76%, with a reproducibility of 86%. Indistinguishable strains occurred in individual patients only, demonstrating that no cross-infection between patients occurred during the 10-month period of collection of strains, and suggesting that the discriminating power of the scheme was, in fact, much higher. The antibiogram, selected as the first stage of the scheme because it was the simplest and cheapest test, proved to be the most discriminatory stage, providing 60% of the final discriminatory power.

Anti-Bacterial Agents↗
PubMed1989

The epidemiology of peritonitis caused by coagulase-negative staphylococci in continuous ambulatory peritoneal dialysis.

The epidemiology of 10 episodes of CAPD peritonitis caused by coagulase-negative staphylococci was studied. The infecting micro-organism was found in prospective skin swabs in six episodes, widely distributed and as the predominant, or equally predominant, organism at each site but was not detected in swabs taken more than 12 weeks before the episode of peritonitis; this suggests recent acquisition. Infecting strains were no more likely to be adherent or to produce slime than non-infecting strains, nor had they any other characteristic detected in our typing scheme that might lead to their detection before peritonitis developed.

Bacterial Adhesion↗
PubMed1989

The preservation of micro-organisms in biological specimens stored at-70 degrees C.

The preservation of micro-organisms that may be found on the skin was studied by storage in liquid media at--70 degrees C. In the first part of the study the performance of 12 varieties of suspending media was evaluated with pure cultures of 17 species of micro-organisms maintained in the laboratory. After storage for 1 year the best medium (Oxoid Nutrient Broth with 15% glycerol) showed a mean survival for all organisms studied of 83.8%, with no significant differences between organisms. Even the worst medium (distilled water) permitted greater than 40% survival at 1 year. No changes in the characteristics of these micro-organisms were detected after 6 months storage in glycerol broth. In the second part of the study nose swabs were suspended in one representative medium (Bacto Nutrient Broth containing 7% glycerol). The mean percentage survival of staphylococci in these suspensions after 1 year's storage at - 70 degrees C was 75.4%. These results indicate that coagulase-negative coagulase-negative staphylococci in samples of skin flora may be stored under these conditions for long periods, greatly reducing the work-load in epidemiological studies of infection.

Cryopreservation↗
PubMed1989

Staff carriage of epidemic methicillin-resistant Staphylococcus aureus.

Twenty-six nurses were repeatedly screened for carriage of epidemic methicillin-resistant Staphylococcus aureus (EMRSA) immediately before and after duty periods in which they solely attended six patients widely colonized with two EMRSA strains distinguishable by plasmid analysis. EMRSA carriage was detected in 13 nurses. Three EMRSA carriage patterns emerged: transient carriage in 12 nurses, when the EMRSA was isolated from noses or fingers of nurses after duty but was gone before their next day's duty; short-term nasal carriage, seen on occasion in 4 of these 12 nurses, when EMRSA carriage was detected on two consecutive screens; and persistent nasal carriage, seen in 1 nurse only, when the EMRSA was seen on more than two consecutive occasions. All but one of these incidents of carriage could be explained by close patient, rather than environmental, exposure and occurred despite an intensive control programme. Transient or short-term carriage in nurses probably resulted in transfer of the EMRSA between patients. Staff decontamination should be considered following a period of cohort nursing of EMRSA patients, especially if staff members are shortly to nurse unaffected patients. Our findings may explain some of the difficulties in controlling EMRSA.

Air Microbiology↗
PubMed1989

[Serologic markers of viral hepatitis B in drug addicted++ patients at the Hermilio Valdizán Hospital].

A study was done in 36 drug addict patients at the H. Valdizan Hospital We studied serological markers for Hepatitis B: HBsAg Anti-HBc, and anti-HIV was also made. They were not IV abusers. Five patients (13.8%) were positive for HBsAg and 6 (16.6%) for anti-HBc. Anti-HIV was negative in all the cases, that obtained from our results compared with the general adult population from peruvian coast are high. In relation to the information obtained, the transmission route would be diverse, considering an important one the sexual route. 44 drug addicts were seen in 1988 at this Hospital, 36 cases could be a representative number, although we think we need to extend this study to a bigger population to establish the actual prevalence of this infection among these particular patients. This information could help to advice preventive and control health measures.

Adolescent↗
PubMed1988

Epidemic multiresistant Escherichia coli infection in West Lambeth Health District.

A year-long outbreak of multiresistant Escherichia coli K52 H1, predominantly serogroup O15, is reported from south east London. Most patients had urinary tract infections, some with septicaemia; but some cases of septicaemia were associated with pneumonia, meningitis, and endocarditis--unusual infections for E coli. 3 of these patients died. The organism was acquired in the community, and its source is still being investigated.

Adolescent↗