FIS 98 Abstracts Al7

THREE CASES OF PYOMYOSITIS IN PREVIOUSLY HEALTHY ADULTS. J Sandoe’ T Collyns’, G A> Radcliffe*, J Lawton*, K Kerr’ and M Denton’. Depts of Microbiology’ & Orthopaedics2, The General Infirmary, Leeds, UK.

We describe three cases of pyomyositis that occurred in previously fit and healthy adults. Case one was a 76 year old man who presented with difficulty walking, a painful, swollen right thigh, pyrexia, raised white cell count (WCC) and C-reactive protein (CW). Streptococcus pyogenes was isolated from pus drained at surgery. Case two was a 79 year old woman who presented a painful swollen left calf, leg weakness raised WCC and CRP but no fevers. Salmonella enteritidis was isolated from pus drained at surgery. She subsequently gave a history of a self-limiting diarrhoeal illness two months earlier when on holiday in Ibiza. Case three involved a 37 year old woman who presented with a painful, swollen right thigh and shoulder, pyrexia, raised WCC and CRP. S. pyog&es was isolated from pus drained from both sites. Magnetic resonance imaging was an invaluable tool in making the diagnosis in all three cases. Each patient made a full recovery following surgical drainage and appropriate antibiotic therapy.

DISTRIBUTION OF TEICOPLANIN- AND VANCOMYCIN-RESISTANT STRAINS AMONGST COAGULASE-NEGATIVE STAPHYLOCOCCI IN A TEACHING HOSPITAL. M Khan and R Holliman, Department of Medical Microbiology, St. George’s Hospital, London, SW17 OQT, UK.

182 coagulase-negative staphylococci (CONS) from blood cultures were identified by ID 32 Staph and investigated for minimum inhibitory concentration (MIC) for vancomycin and teicoplanin by Etest. The major species identified were Staphylococcus epidertnidis (S. epidermidis) 96 (52.7%), S. capiris 23 (12.60/o), S. honzinis I9 (10.4%), S. haemo!vticus 12 (6.5%), S. warneri 9 (4.9%) and Micrococcus roseus 8 (4.3%). Ten other species were <2%, each. The MICs varied between 0.06-32pgAnl for teicoplanin and 0.38-i pg/ml for vancomycin. Among 18 teicoplanin-resistant strains, 16 strains were intermediate-resistant (MIC 6-16ugAnl) while one S. capifis and S. haemolyficus were high-resistant (21& 32@ml, respectively). Teicoplanin-resistant strains belonged lo S. epidernridis (12). S. haemolyticus (3), Micro.roseus (2) and S. capifis (1) species. Poor correlation was observed between Etest and disc diffusion. Six of the 10 5’. epidermidis and one of the two Micro. roseus. spp with MICs between 6-12pg/ml appeared susceptible to teicoplanin by disc diffusion. FiReen (100%) strains from surgical units were metliicillin-resistant by disc diffusion as compared to I5 (75%) strains (P < 0.005) from NNU and other units. All the isolates were susceptible to vancomycin by Etest and disc diffusion. We conclude that vancomycin remains the empirical treatment of choice for serious infections which may be associated with CONS.

ORIGINS OF GRAM-POSITIVE BACTERIA CAUSING BACTERAEMIA IN A BONE MARROW TRANSPLANT PATIENT. H.F. KennedyI, D. Morrison3, M.E. Kaufmann4, MS. Jacksor?, J. Bagg5, B.E.S. Gibson*, C.G. Gemmells, J.R. Michiel. Departments of ‘Microbiology and *Haematology, Yorkhill NHS Trust, 3Scottish MRSA Reference Laboratory, and 5Department of Oral Microbiology, Glasgow Dental School, North Glasgow University/NHS Trust, Glasgow UK. *Central Public Health Laboratory, London, UK.

While the oral cavity may be the portal of entry for viridans streptococci causing bacteraemia in immunocompromised patients, central venous catheters are commonly considered the major source of coagulase- negative staphylococci. This report describes an episode of polymicrobial bacteraemia caused by Streptococcus oralis and Staphylococcus epidermidis followed by several episodes of S. epidermidis bacteraemia in a 15 year-old boy post bone marrow transplantation. Pulsed- field gel electrophoresis of SmaI chromosomal DNA digests, used to compare isolates from blood culture with colonizing viridans streptococci and coagulase- negative staphylococci, revealed that during a period of severe oral mucositis, the mouth was the source of both bacterial species causing the first episode of bacteraemia, while the central venous catheter was the origin of S. epidermidis causing subsequent episodes. Both the oral mucosa and central venous lines should be considered as potential sources of organisms associated with bacteraemia in immunocompromised patients.

THE CHANGING PATTERN OF BACTERAEMIA AT A CHILDREN’S HOSPITAL, 1977, 1987 & 1997. m and R.H. George, Department of Microbiology, Children’s Hospital, Birmingham, B4 6NH, UK

We reviewed experience of bacteraemia at ten yearly intervals in order to determine the extent of changes in the incidence and microbial causes. The number of episodes of bacteraemia increased from 28 in 1977, through 118 in 1987, to 388 in 1997, equating to incidences of 4.3, 12.0 and 19.0 episodes per 1000 admissions 28.9% of episodes in 1977 were hospital- acquired, compared with 61.0% and 42.9% in succeeding decades. 11.9% of episodes in 1997 were polymicrobial, compared with 7.9% and 5.9% previously. In 1977, Staph. aureus, .!5 cali and Strep. pnenmoniae were the most common species, accounting for 58.5% of isolates. By 1987 coagulase-negative staphylococci (CNS) were the most common species (28.6% of isolates). In 1997 CNS were again the most common species (35 6% of isolates), whilst enterococci (7 7%) and Klehsiella spp. (7.1%) now outnumbered k;. co/i (6.8%) and pneumococci (3.6%). The proportion of fungaemias remained remarkably constant (2.4%, 2.4% and 2.3%). The incidence of bacteraemia continues to increase, and the spectrum of causative microorganisms is constantly changing, reflecting the increasing numbers of compromised patients