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Disorders of local immunity associated with diabetes, neuropathy, vascular disease and pressure lesions all contribute to the pathogenesis of diabetic foot lesions. Diabetic foot infections are frequently encountered, comprising multifactorial pathology and high morbidity and mortality rates. Microbiological sampling is indicated only when infection is suspected clinically, that is, when a lesion presents a minimum of two of the following six signs: erythema, heat, pain, tumefaction, induration or purulent discharge.

We report on a leukemic patient who suffered from a persistent, generalized, and eventually fatal Staphylococcus epidermidis infection during prolonged aplasia. Over a 6-week period, we isolated a genetically and phenotypically unstable S. epidermidis strain related to an epidemic clone associated with hospital infections worldwide. Strikingly, the strain showed a remarkable degree of variability, with evidence of selection and increasing predominance of biofilm-producing and oxacillin-resistant variants over time. Thus, in the early stages of the infection, the strain was found to generate subpopulations which had spontaneously lost the biofilm-mediating ica locus along with the oxacillin resistance-conferring mecA gene. These deletion mutants were obviously outcompeted by the ica- and mecA-positive wild-type genotype, with the selection and predominance of strongly biofilm-forming and oxacillin-resistant variants in the later stages of the infection. Also, a switch from protein- to polysaccharide intercellular adhesin/poly-N-acetylglucosamine (PIA/PNAG)-mediated-biofilm production was detected among ica-positive variants in the course of the infection. The data highlight the impact of distinct S. epidermidis clonal lineages as serious nosocomial pathogens that, through the generation and selection of highly pathogenic variants, may critically determine disease progression and outcome.

We report the case of a 81-year-old, immunocompromised Patient, admitted to our hospital with new-onset headaches and word-finding difficulties. The MRI of the brain revealed a temporal mass on the left with marginal contrast-enhancement. During the next days Listeria monocytogenes grew in the bloodcultures so that the diagnosis of a brain-abscess caused by Listeria was established. Due to the localisation, surgical drainage of the abscess was not possible, so that a prolonged antibiotic therapy lasting over 4.5 months was initiated. The MRI after therapy demonstrated no abscess persistence. Listeria mostly cause infections in the immunocompromised, elderly, newborn or pregnant host. Next to bacteraemia without a focus, CNS-invasion with meningitis, meningoencephalitis or less frequent abcess-formation (5-10%) is the most important manifestation.

We report the difficulties encountered in diagnosing leptospirosis in an 85-year-old man who presented with non-specific signs and symptoms. Initially, a wide haematologic and oncologic work-up without significant results was performed, as symptoms of several organ dysfunctions emerged and the clinical course showed a rapid deterioration. After several days without a definite diagnosis, the infection was finally detected after reviewing all results and considering the patient's profession as a farmer. After receiving appropriate antibiotic treatment the patient recovered fully.