| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Case Report |
1 Department of Microbiology and Infectious Diseases, PathWest Laboratory Services, Royal Perth Hospital, Wellington St, Perth, WA 6000, Australia
2 Division of Microbiology and Infectious Diseases, PathWest Laboratory Services, Queen Elizabeth II Medical Centre, Hospital Avenue, Nedlands, WA 6009, Australia
3 Institut für Angewandte Mikrobiologie, Justus-Liebig Universität Giessen, D-35392 Giessen, Germany
Correspondence
Peter Kämpfer
peter.kaempfer{at}agrar.uni-giessen.de
Received 6 March 2007
Accepted 27 June 2007
Abbreviations: IVTA, intravitreal triamcinolone acetonide.
The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of isolate 9571414 J is AM409316.
 |
Case report |
|---|
 TOP Case report REFERENCES |
|---|
Vitreous fluid (0.1 ml) was aspirated and sent for analysis. The Gram stain was negative for white cells and bacteria. The remainder of the specimen was inoculated onto GC agar [Oxoid GC agar base+5 % chocolate horse blood+essential growth factor supplement 1 % (IsoVitalex)] and into serum broth. After 6 days of incubation at 35 °C in 5 % CO2, numerous small pink-pigmented colonies were observed on GC agar. No growth was observed in serum broth. No other micro-organism was cultured from the specimen. Gram staining of the colonies showed short Gram-positive bacilli that tested positive for catalase. The organism was not acid-fast on Kinyoun's staining. Biochemical characterization using the API Coryne Identification System (bioMérieux) showed positive reactions for alkaline phosphatase, 
-glucosidase and catalase (biocode 0110004) after 24 h incubation. A detailed electron microscopic investigation showed that the cells were coccoid to irregular, with a dense ‘fuzzy coat’ surrounding the capsule (Fig. 1
).
|
0.1 between first and third choice). Results of the physiological characterization (biochemical tests based on carbon substrate utilization and hydrolyses of various chromogenic substrates according to Kämpfer et al., 1991) for strain 9571414 J were in accordance with those reported for W. muralis DSM 44343T (Kämpfer et al., 1999). DNA–DNA hybridization experiments were performed with 9571414 J and W. muralis DSM 44343T using the method described by Ziemke et al. (1998) modified as described by Kämpfer et al. (1991). Strain 9571414 J showed 100 % DNA–DNA similarity (mean value of two hybridizations) to W. muralis DSM 44343T, indicating clearly that the strain is a member of this species. MIC estimation was performed on the isolate using the Etest method (AB Biodisk). A 0.5 McFarland suspension of the isolate was lawn-inoculated onto GC agar plates, and Etest strips containing benzylpenicillin, ciprofloxacin, ceftazidime and vancomycin were placed onto the plates. The plates were then incubated at both 30 °C and 35 °C in 5 % CO2, and read at 24 h intervals together with control plates. Confluent growth was observed on the control plate incubated at 30 °C for 48 h; there was minimal growth on the control plate incubated at 35 °C for 72 h. MICs were therefore estimated following growth at 30 °C for 48 h, with the following results: benzylpenicillin, 1 mg l–1; vancomycin, 1 mg l–1; ciprofloxacin, 0.125 mg l–1; and ceftazidime, >32 mg l–1.
The patient received intravitreal vancomycin (10 mg) and ceftazidime (20 mg) immediately following the collection of the vitreous fluid specimen as per institutional protocol. On review the following day, improvement in visual acuity in the left eye to ‘count fingers’ was noted, but a small hypopyon (pus in the anterior chamber) was present, and moderate numbers of cells were seen in both the aqueous chamber and vitreous on slit-lamp examination. By the time that the organism had been isolated, the patient had been discharged for follow-up; visual acuity improved, but remained reduced at 6/36. Given the temporal relationship between the injection and the development of endophthalmitis (24 h), the fact that there was no clinical suspicion of endogenous endophthalmitis, and the fact that no other organism was identified on culture, it was considered likely that W. muralis was the cause of this infection and was inoculated into the eye at the time of IVTA injection. However, as the equipment used to administer the injection and the medication vial containing triamcinolone had been disposed of by the time that the organism was isolated, the source of the infection could not be proven. No further cases of W. muralis endophthalmitis have been identified at our institution either prior to, or subsequent to, this case.
The genus Williamsia was described by Kämpfer et al. (1999) to accommodate an unusual mycolic-acid-containing actinomycete. Williamsia takes an intermediate position between Rhodococcus (mycolic acid carbon chain length of 34–45) and Gordonia (mycolic acid carbon chain length of 54–66) (Kämpfer et al., 1999). At the time of writing, the taxon contains four recognized species: Williamsia deligens (Yassin & Hupfer, 2006), Williamsia maris (Stach et al., 2004), W. muralis (Kämpfer et al., 1999) and Williamsia marianensis (Pathom-aree et al., 2006). These species encompass strains isolated from human blood, deep-sea sediment and indoor building materials.
W. muralis has been isolated from indoor building materials (Kämpfer et al., 1999). Only one clinical case of respiratory tract infection by W. muralis has been described so far (del Mar Tomas et al., 2005).
A second Williamsia species, W. deligens, has been isolated from clinical specimens, but no infection has been reported along with the description of this species (Yassin & Hupfer, 2006). To our knowledge, this is the first report of a ‘sterile-site’ infection caused by W. muralis.
|
ACKNOWLEDGEMENTS |
|---|
|
REFERENCES |
|---|
|
TOPCase reportREFERENCES |
|---|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | J MED MICROBIOL | MICROBIOLOGY | J GEN VIROL | ALL SGM JOURNALS |
