Outbreak of Corynebacterium striatum infection in an Italian general intensive care unit

Abstract number: 1734_162

Iaria C., Stassi G., Spinella S.G., Costa G.B., Biondo C., Gerace E., Ricciardi F., David A., Cascio A.

Background: Intensive care units (ICUs) are known to be a focus for the emergence and dissemination of multiresistant bacteria mainly because the most severely-ill patients can be found in the ICU, and almost all of these patients will have been exposed to intense antibiotic pressure and exogenous bacterial colonisation. Corynebacterium spp. are widely disseminated in the environment and constitute part of the normal skin and mucous membrane flora. Although both C. amycolatum and C. jeikeium are currently recognized as important pathogens, the significance and prevalence of C. striatum as a causative agent of disease are not well understood. We describe an outbreak occurred in the ICU of our University hospital and try to evaluate the clinical significance of C. striatum infection and risk factors associated with it.

Case report: In first months of 2006 13 strains of Kocuria kristinae were isolated from 8 patients admitted in ICU. Routine diagnostic cultures of the clinical specimen had been used and identification performed using Biomeieux VITEK 2 system GP card. Antibiotic sensitivity test was performed using the disc diffusion method according to Clinical and Laboratory Standards Institute guidelines for Staphylococcus. All the isolates exhibited the same pattern of antibiotic resistance being sensitive only to vancomycin, teicoplanin and linezolid. Considering that in our lab K. kristinae had never been isolated before and that using standard biochemical analysis misidentification of coagulase negative Staphylococcus as Kocuria had been reported, a genotypic assay (16s rRNA) was performed. Surprisingly, all the strain tested were identified as C. striatum.

Overall C. striatum was isolated from 7 bronchial aspirates relative to 5 patients, one from a central venous catheter tip and from 5 blood cultures relative to 5 patients. The demographic and clinical data of the patients are reported in table 1. In no one of the patients in which C. striatum was isolated from bronchial aspirate a diagnosis of ventilatory associate pneumonia was made. Patients n.4 had the parameters of sepsis and died notwithstanding he was treated with appropriate antibiotic therapy.

PatientaUnderlying illnessClinical specimensDays in ICUT (°C)PulseWBC ×103TherapyOutcome
1, M/73Cranial traumaN.3 bronchial aspirates7379012.5TeicoplaninDied
2, M/16Multiple traumaCVC tip93711727.2CeftazidimeRecovered
3, M/59Strokebronchial aspirates19379010.0TeicoplaninRecovered
4, F/16Multiple traumaN.3 blood cultures538.210010.3Teicoplanin MeropenemDied
5, M/33Multiple traumabronchial aspirate9387816.6TeicoplaninRecovered
6, F/80StrokeN.2 blood cultures60379014.4Piperacillin TeicoplaninRecovered
7, M/69Strokebronchial aspirate54010319.6Linezolid LevofloxacinRecovered
8, F/55Cerebral metastasisbronchial aspirate2438.59017TeicoplaninDied
aID, Gender/Age.

Conclusions: Our report highlights the importance of C. striatum as a potential human pathogen in ICU patients even if its pathogen role remains to be clarified. Furthermore, we signal the possible misidentification of C. striatum as K. kristinae using the bioMérieux VITEK 2 GP card.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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