Activity of the antiseptic polyhexanide against meticillin-susceptible and meticillin-resistant Staphylococcus aureus.

Staphylococcus aureus is one of the most important pathogens, with increasing emergence of meticillin-resistant S. aureus (MRSA) strains. This is associated not only with multiresistance to antibiotics but also with increasing resistance to topical antibiotics and antiseptics. As the antiseptic polyhexanide has only a low risk of emergence of resistant strains, the aim of the study was to obtain data on the sensitivity of S. aureus towards polyhexanide. The effect of polyhexanide was tested against 80 meticillin-susceptible S. aureus (MSSA) and 80 MRSA strains from sporadic cases as well as against 6 MRSA outbreak strains. The clonal diversity of the 166 strains was proven by pulsed-field gel electrophoresis (PFGE). Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined by the serial broth microdilution technique according to DIN 58940. Time-kill studies were performed for reference strains MSSA ATCC 29213 and MRSA ATCC 33591. MICs and MBCs in the range of 0.5-2mg/L were found. According to a created epidemiological cut-off (ECOFF) value of 4mg/L, all strains were regarded as susceptible to polyhexanide, including MRSA epidemic strains and MSSA and MRSA sporadic strains with various antibiotic susceptibility patterns. Addition of up to 4% albumin to the test medium did not change the MICs and MBCs. Time-kill studies showed reduction rates of 4log10CFU/mL for 200mg/L and 5log10CFU/mL for 400mg/L polyhexanide within 5-30min. It is concluded that polyhexanide is suitable for topical eradication of S. aureus.

Invasive zygomycosis in patients with graft-versus-host disease after allogeneic stem cell transplantation.

Invasive mold infections are a threat to immunosuppressed patients such as patients with graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). Up to 10% of SCT recipients develop invasive aspergillosis (IA). Invasive zygomycosis (IZ) may occur during treatment against IA. Here we report 4 SCT patients with GVHD diagnosed with IZ. All patients had received myeloablative hematopoietic SCT and developed chronic GVHD requiring systemic immunosuppression. Underlying diseases were acute lymphocytic leukemia (2), osteomyelofibrosis, and multiple myeloma. All patients had developed pulmonary infiltration that led to initiation of antifungal therapy. Treatment for IA was voriconazole, caspofungin, or itraconazole. Organs involved with zygomycosis were lung, nasal sinus, skin, and kidney. Treatment with liposomal amphotericin and posaconazole was initiated in all patients, and 2 patients also had surgical debridement as well. Despite intensive treatment, no patient survived. IZ is becoming more common in patients with GVHD on successful treatment for IA. Even non-specific symptoms are suspicious in this group of patients and need to be evaluated by vigorous diagnostics. Despite effective antifungals and surgical intervention, the prognosis is grim in patients with active GVHD, as immunoreconstitution is mandatory for successful management.

Subcutaneous fistulae in a patient with femoral hypoplasia due to Actinomyces europaeus and Actinomyces turicensis.

Infections due to Actinomyces europaeus or Actinomyces turicensis have only rarely been reported. We describe a case of chronic fistulae caused by a coinfection with A. europaeus and A. turicensis in an immunocompetent male patient with a severe congenital femur hypoplasia. Actinomycosis is most probably the consequence of a postoperative wound infection after a prior surgical intervention. Both Actinomyces species were identified by 16S rRNA gene sequencing. The Actinomyces-caused fistulae were treated by excision and a 1-week course of i.v. vancomycin followed by a 1-week course of p.o. cefuroxime.

PCR based identification and discrimination of agents of mucormycosis and aspergillosis in paraffin wax embedded tissue.

BACKGROUND: Invasive fungal infections are often diagnosed by histopathology without identification of the causative fungi, which show significantly different antifungal susceptibilities. AIMS: To establish and evaluate a system of two seminested polymerase chain reaction (PCR) assays to identify and discriminate between agents of aspergillosis and mucormycosis in paraffin wax embedded tissue samples. METHODS: DNA of 52 blinded samples from five different centres was extracted and used as a template in two PCR assays targeting the mitochondrial aspergillosis DNA and the 18S ribosomal DNA of zygomycetes. RESULTS: Specific fungal DNA was identified in 27 of 44 samples in accordance with a histopathological diagnosis of zygomycosis or aspergillosis, respectively. Aspergillus fumigatus DNA was amplified from one specimen of zygomycosis (diagnosed by histopathology). In four of 16 PCR negative samples no human DNA was amplified, possibly as a result of the destruction of DNA before paraffin wax embedding. In addition, eight samples from clinically suspected fungal infections (without histopathological proof) were examined. The two PCR assays detected a concomitant infection with Absidia corymbifera and A fumigatus in one, and infections with Rhizopus arrhizus and A fumigatus in another two cases. CONCLUSIONS: The two seminested PCR assays described here can support a histopathological diagnosis of mucormycosis or aspergillosis, and can identify the infective agent, thereby optimising antifungal treatment.

Extranodal marginal zone B cell lymphoma of MALT type involving the mucosa of both the urinary bladder and stomach.

Primary lymphoma of the urinary bladder is a very rare tumour. A bladder tumour was found in a 57 year old man with obstructive dysuria. It was found by histological and immunohistohistochemical investigation to be an extranodal marginal zone B cell lymphoma. Lymphoepithelial lesions were absent, but were found in a clinically silent gastric lymphoma discovered four weeks later during staging investigations; this gastric lymphoma was negative for Helicobacter pylori by breath test and molecular biological analysis. Sequencing of the clonal immunoglobulin heavy chain gene in both tumours indicated the same precursor cell, of follicular or post follicular origin. In synopsis, the data suggested that this was a case of primary lymphoma of the bladder with involvement of the stomach. The application of a chromosome 3 specific alpha satellite probe revealed trisomy 3. A tumour with these characteristics arising as a lymphoma of the bladder with a metachronous involvement of the gastric mucosa has not been described previously.

Molecular pathogenesis of Epstein-Barr virus associated posttransplant lymphomas: new insights through latent membrane protein 1 fingerprinting.

BACKGROUND: Fingerprint amino acid patterns within the carboxy terminus of the latent membrane protein (LMP1) oncoprotein of Epstein-Barr virus (EBV) allow individual strain identification at the molecular level. LMP1 is expressed in the tumor cells of EBV-associated posttransplant lymphomas (PTLs) and the LMP1 genome is also identified in lymphocytes of most donors of allogeneic bone marrow. Therefore, LMP1 genotyping in donor lymphocytes and PTL tumor cells, together with sex chromatin determination of tumor cells, allows to determine the origin of PTL tumor cells and the origin of individual EBV strains harboured by them. METHODS: We traced the origin of aggressive PTLs occurring in six patients after allogeneic T cell-depleted stem cell transplantation (allo-SCT). DNA was extracted from donor lymphocytes and PTLs of recipients and amplified with LMP1-specific primers in each case. A comparative sequence analysis of the fingerprint LMP1 region identified in donor lymphocytes and lymphoma was performed. RESULTS: One lymphoma of donor origin occurred after highly selected CD34+ PBSCT and contained the same LMP1 genotype as the donor lymphocytes. Three lymphomas of recipient origin had deletions within the carboxy terminus of LMP1, not identified in the donor strains. All lymphomas occurred in the setting of allo-SCT and had a rapid clinical course. CONCLUSIONS: These results show that highly selected CD34+ PBSCT does not protect against transfer of EBV positive founder cells of donor type PTL and that, after allo-SCT, recipient type PTLs are not uncommon. Outgrowth of recipient type lymphoma may be favoured by LMP1 deletion variant strains present in recipient lymphocytes.

Human papillomavirus type 16-associated primary squamous cell carcinoma of the rectum.

Primary squamous cell carcinoma (SCC) of the colorectum is an extremely rare malignancy of unknown etiology and pathogenesis. We describe an 87-year-old man with primary SCC of the rectum. Routine histology demonstrated a squamous metaplasia-dysplasia sequence of the rectal mucosa with subsequent malignant transformation. Molecular biologic analysis using polymerase chain reaction (PCR) and in situ hybridization revealed the presence of human papillomavirus type 16 (HPV-16) DNA within metaplastic, dysplastic, and SCC lesions and in tumor-free rectal mucosa. Moreover, nested reverse-transcription PCR showed transcriptional activity of the viral E6/E7 oncogenes in tumor tissue and tumor-free rectal mucosa. By contrast, 4 typical adenocarcinomas of the rectum and their adjacent normal mucosa were found to be negative for HPV by nested PCR. In line with the well-established concept of HPV-associated anogenital carcinogenesis, our results strongly suggest an etiologic role of HPV-16 in the pathogenesis of the metaplasia-dysplasia-SCC sequence in the case described.

Detection of c-kit mutation Asp 816 to Val in microdissected bone marrow infiltrates in a case of systemic mastocytosis associated with chronic myelomonocytic leukaemia.

BACKGROUND/AIMS: The occurrence of myeloid leukaemia in patients with systemic mastocytosis is a well recognised phenomenon. However, the pathophysiological basis of such a coevolution has not been clarified. Recent data have shown that the c-kit mutation Asp 816 to Val is detectable in neoplastic mast cells in most patients with systemic mastocytosis, including those who have associated haematological disorders. The aim of this study was to study clonal disease evolution by analysing bone marrow cells from a patient with systemic mastocytosis and associated chronic myelomonocytic leukaemia (CMML) for the presence of this mutation. METHODS: The DNA of microdissected bone marrow cells from a patient with systemic mastocytosis and associated CMML was analysed for the presence of the c-kit mutation Asp 816 to Val by means of HinfI digestion and direct sequencing of semi-nested polymerase chain reaction (PCR) products. RESULTS: The two neoplasms could easily be identified and discriminated in paraffin wax embedded bone marrow sections by tryptase and chloroacetate esterase staining. A total number of 10 tryptase positive systemic mastocytosis infiltrates and 10 tryptase negative CMML infiltrates were removed by microdissection. As assessed by HinfI digestion and direct sequencing of semi-nested PCR products, the c-kit mutation Asp 816 to Val was detected in five of seven systemic mastocytosis infiltrates and four of six CMML infiltrates. By contrast, no c-kit mutation Asp 816 to Val was found in bone marrow infiltrates in patients with CMML without associated systemic mastocytosis (n = 20). CONCLUSION: These data support a monoclonal evolution of systemic mastocytosis and concurrent CMML in the patient studied.

Detection of Paracoccidioides brasiliensis in tissue samples by a nested PCR assay.

A nested PCR assay for the detection of Paracoccidioides brasiliensis DNA was evaluated, using a sequence of the immunogenic gp43 gene as a target. This gene encodes an outer membrane protein unique to this dimorphic fungus. DNA from six clinical isolates and the ATCC strain 60885 of P. brasiliensis, as well as DNA from closely related fungi, was examined to determine detection limits and cross-reactions. PCR was done on DNA extracts of lung homogenates from 23 experimentally P. brasiliensis-infected and two uninfected BALB/c mice and from 20 Histoplasma capsulatum-infected ICR mice. The results were compared to quantitative cultures. A detection limit of 0.5 fg of specific DNA was determined using cloned plasmid DNA. In all seven P. brasiliensis isolates, the expected 196-bp nested PCR product was found. Their sequences were 100% identical to the gp43 gene sequence in GenBank. DNA extracts of all other, related fungi were negative. The PCR assay was positive in 21 out of 23 culture-positive lung homogenates with concentrations of 1 x 10(3) to 1.3 x 10(7) CFU of P. brasiliensis per g of lung. Uninfected BALB/c mice and H. capsulatum-infected mice samples gave negative results. The high sensitivity and specificity of this new nested PCR assay for the detection of P. brasiliensis in tissue samples were demonstrated. The assay may be useful for diagnosis in human tissue samples.

Disseminated fatal human cytomegalovirus disease after severe trauma.

OBJECTIVE: Disseminated human cytomegalovirus (HCMV) disease is considered to be uncommon in critically ill but otherwise not immunosuppressed patients. We describe the case of a trauma victim who developed fatal HCMV disease that initially presented as pseudomembranous colitis and resulted in sudden cardiac death. DESIGN: Case report of fatal HCMV disease in a previously healthy patient after multiple trauma. SETTING: Surgical intensive care unit (ICU). PATIENT: A 63-yr-old male patient with multiple injuries. INTERVENTIONS AND MEASUREMENTS: Under ICU treatment, symptoms of HCMV reactivation presenting as pseudomembranous colitis appeared 32 days after trauma. Detailed laboratory examinations for HCMV infection were performed, including complement fixation titer, immunoglobulin G and M, polymerase chain reaction, and virus isolation. RESULTS: The intravital detection of HCMV DNA in serum, leukocytes, and a colonic biopsy specimen indicated HCMV reactivation. Postmortem examination findings, including positive viral cultures, showed severe disseminated HCMV disease with involvement of the colon and myocardium. CONCLUSIONS: The lack of specific clinical symptoms of HCMV disease and the delay until viral culture results are available make an exact and timely diagnosis of HCMV disease difficult. Its prevalence in critically ill but otherwise not immunosuppressed patients is currently unknown and possibly underestimated. Because severe illness or trauma can cause immunodysfunction and, thus, may contribute to an increased rate of HCMV disease, detailed studies are warranted to evaluate the real risk in the ICU setting.

Mechanisms and consequences of enterovirus persistence in cardiac myocytes and cells of the immune system.

In humans and experimental murine models enteroviruses, and in particular coxsackieviruses of group B (CVB), may induce chronic myocarditis associated with a persistent type of heart muscle infection. Persistent myocardial infection has been characterized by restricted viral replication and gene expression, which is capable of sustaining chronic inflammation. Altered replication and transcription of the virus, in addition to an immune response insufficient to recognize and clear infected cells entirely, are essential mechanisms for initiation and maintenance of persistent heart muscle infection. Viral cytotoxicity was found to be crucial for organ pathology both during acute and persistent infection, indicating that enterovirus myocarditis is a virus-induced rather than an immune-mediated disease. Notably, resistance to the development of persistent heart muscle infection is not linked to the H-2 haplotype of the host. In addition to persistently infected myocytes, detection of the replicative minus-strand RNA intermediate provided evidence for virus replication in lymphoid cells of the spleen, predominantly in splenic B lymphocytes, during the course of the disease. Whereas viral RNA was also detected in certain CD4+ helper T cells and Mac1+ macrophages, no enteroviral genomes were identified in CD8+ T cells. Detection of infected activated B lymphocytes both in heart tissue of CVB3-infected immunocompetent mice and syngenic SCID mice receiving splenocytes from CVB3-infected donors support the concept that B cell traffic may contribute to maintenance of chronic disease. Dissection of the diversity of viral and host-specific determinants in susceptible and resistant hosts will allow us to define the protective mechanisms that mediate resistance to the development of life-threatening acute and chronic enterovirus myocarditis.

Multicenter quality assessment of PCR methods for detection of enteroviruses.

We conducted a multicenter evaluation of commercial and in-house PCR methods for the detection of enteroviruses. Three coded panels of test and control RNA samples, artificial clinical specimens, and representative enterovirus serotypes were used to assess amplification methods, RNA extraction methods, and reactivities with different enterovirus serotypes. Despite several differences between PCR methods, there was good agreement, although some variation in sensitivity was observed. Most PCR methods were able to detect enterovirus RNA derived from 0.01 50% tissue culture infective dose (TCID50) and were able to detect at least 1 TCID50 of enterovirus in cerebrospinal fluid, stool, or throat swab specimens. Most were also able to detect a wide range of enterovirus serotypes, although serotypic identification was not possible. Some laboratories experienced false-positive results due to PCR contamination, which appeared to result mainly from cross-contamination of specimens during RNA extraction. Provided that this problem is overcome, these PCR methods will prove to be a sensitive and rapid alternative to cell culture for the diagnosis of enterovirus infection.

Nebennierentuberkulose als seltene Ursache einer adrenocorticalen Insuffizienz (Morbus Addison).

Adrenocortical insufficiency (Addison's disease) is a functional diagnosis. At the beginning of this century, tuberculosis was recognized as the main etiological cause (50-70%). Today, however, tuberculosis represents only 10% of the cases. Adrenocortical insufficiency is mainly caused by autoimmune adrenalitis (more than 50%). Unilateral adrenocortical disease is usually asymptomatic or presents, as in the case described, with minor symptoms. This case report of adrenal tuberculosis illustrates the current challenges of diagnosis and therapy.

Coxsackie B virus and its interaction with permissive host cells.

BACKGROUND: Observations in humans and the results of experiments on laboratory animals have provided evidence that coxsackieviruses of group B (CVB) are major etiologic agents of acute and chronic enterovirus myocarditis and various other virus-induced diseases. OBJECTIVE: This minireview briefly summarizes the investigations to elucidate various molecular mechanisms for the induction and maintenance of persistent CVB infections. With regard to the recent findings that CVB may use several different receptor proteins, this article focuses on virus-host cell interactions and the potential impact of these interactions for enteroviral replication. STUDY DESIGN: The interaction of CVB with specific cell surface proteins was analyzed in cultured cell lines and murine tissues at the level of virus attachment and virus internalization. As example for the interaction of CVB with intracellular proteins, the state of p21rasGTPase-activating protein (RasGAP) was investigated in mock-infected and CVB3-infected HeLa cells. RESULTS AND CONCLUSIONS: The experiments to elucidate the virus receptor interactions revealed the necessity to differentiate between CVB attachment proteins and proteins involved in virus internalization. Since more than one protein may be required to initiate the uptake of CVB into permissive host cells, a model of the putative interaction of these proteins within a multimeric receptor complex is proposed. It is further tempting to speculate that the presence of multiple attachment proteins may influence the tissue tropism of CVB as well as pathogenicity.

The activation domain of simian immunodeficiency virus SIVmac239 Rev protein is structurally and functionally analogous to the HIV-1 Rev activation domain.

The Rev proteins of primate immunodeficiency viruses are essential transactivators for the switch from early to late phase in the viral replication cycle. By mutational analysis, a putative activation domain (AD) has been assigned to the carboxy-terminus. This leucine-rich stretch of amino acids proved to be essential for the transactivating properties of HIV-1 Rev. Some mutants in the AD transdominantly inhibit the function of wild-type Rev protein very efficiently. We identified a similar domain structure for SIVmac239 Rev by sequence comparison and in vitro mutagenesis. The leucine/isoleucine residues of the SIVmac239 Rev activation domain appeared to be of similar importance for function. The mutants of these residues in the SIV AD displayed a dominant negative phenotype on both HIV-1 and SIVmac 239 rev-responsive elements (RRE). The prokaryotically expressed wild-type and mutant proteins were analyzed for RNA-binding properties in a gel-shift assay in vitro. This assay revealed a similar binding pattern of wild-type and transdominant proteins on either RRE.