Identification of bacterial DNA in neutrocytic and non-neutrocytic cirrhotic ascites by means of a multiplex polymerase chain reaction.

BACKGROUND: Even though bacterial cultures of ascitic fluid are negative in up to 65% of the cases of spontaneous bacterial peritonitis (SBP); bacterial DNA (bactDNA) has been frequently detected in episodes of SBP as well as in culture-negative non-neutrocytic ascites. AIMS: To evaluate multiplex polymerase chain reaction (PCR) for pathogen identification in SBP and to determine the prevalence of ascitic bactDNA and its prognostic relevance in hospitalized patients with liver cirrhosis. METHODS: Ascitic fluid from 68 consecutive patients who underwent diagnostic paracentesis was analysed for polymorphonuclear leucocyte (PMN) count, bacterial culture and bactDNA. BactDNA was identified by gel analysis after multiplex PCR of selectively enriched prokaryotic nucleic acids. Correlations of bactDNA status with PMN count, bacterial culture result and 3-month mortality were determined for neutrocytic and for non-neutrocytic ascites. RESULTS: 11/68 patients presented with an elevated ascitic PMN count. BactDNA was detected in 5/5 culture-positive neutrocytic samples, in 1/6 culture-negative neutrocytic samples and in 8/56 culture-negative non-neutrocytic samples. Three-month mortality did not differ with respect to ascitic bactDNA status (7/14 vs. 14/47, P=0.162). 3-month mortality was increased in the presence of ascitic bactDNA for patients older than 65 years (4/5 vs. 4/14, P=0.046) and for patients with a model for end-stage liver disease score >15 (7/10 vs. 9/30, P=0.025). CONCLUSIONS: Identification of ascitic bactDNA is an appropriate alternative to bacterial ascite culture for pathogen identification in patients at risk for SBP. Its prognostic relevance as a proposed marker of bacterial translocation for certain risk groups has to be further evaluated.

Diagnostic odyssey of a cutaneous mycobacteriosis rare in central Europe.

Cutaneous infection with Mycobacterium chelonae is an uncommon disease, although this atypical mycobacterium is an acid-fast bacillus ubiquitous in the environment. It is often misdiagnosed and treated as a fungal or common bacterial infection. We report a case of disseminated atypical mycobacterial skin infection of a 72-year-old woman who was treated with different topical and systemic antimycotic and antibiotic drugs over a period of 5 months without remarkable improvement. Eventually, repeated tissue cultures on special medium and performance of PCR led to the diagnosis of M. chelonae infection. The patient was treated successfully with oral clarithromycin within 8 weeks. In case of abscessing cutaneous infection, M. chelonae should be considered in the differential diagnosis of prolonged disease when common antibiotics are not effective after 2-4 weeks of treatment.