Typing of Ochrobactrum anthropi clinical isolates using automated repetitive extragenic palindromic-polymerase chain reaction DNA fingerprinting and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.

BACKGROUND: Ochrobactrum anthropi (O. anthropi), is a non-fermenting gram-negative bacillus usually found in the environment. Nevertheless, during the past decade it has been identified as pathogenic to immunocompromised patients. In this study, we assessed the usefulness of the automated repetitive extragenic palindromic-polymerase chain reaction (rep-PCR-based DiversiLab™ system, bioMèrieux, France) and of matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF MS) for typing of twentythree O. anthropi clinical isolates that we found over a four-months period (from April 2011 to August 2011) in bacteriemic patients admitted in the same operative unit of our hospital. Pulsed-field gel electrophoresis (PFGE), commonly accepted as the gold standard technique for typing, was also used. Analysis was carried out using the Pearson correlation coefficient to determine the distance matrice and the unweighted pair group method with arithmetic mean (UPGMA) to generate dendogram. RESULTS: Rep-PCR analysis identified four different patterns: three that clustered together with 97% or more pattern similarity, and one whose members showed < 95% pattern similarity. Interestingly, strains isolated later (from 11/06/2011 to 24/08/2011) displayed a pattern with 99% similarity. MALDI-TOF MS evaluation clustered the twentythree strains of O. anthropi into a single group containing four distinct subgroups, each comprising the majority of strains clustering below 5 distance levels, indicating a high similarity between the isolates. CONCLUSIONS: Our results indicate that these isolates are clonally-related and the methods used afforded a valuable contribution to the epidemiology, prevention and control of the infections caused by this pathogen.

Impact of interleukin-10, soluble CD25 and interferon-γ on the prognosis and early diagnosis of bacteremic systemic inflammatory response syndrome: a prospective observational study.

INTRODUCTION: The pathophysiology of sepsis consists of two phases. A first phase characterized by a substantial increase of pro-inflammatory mediators including cytokines and systemic inflammatory markers, and a second phase (immunoparalysis, immunodysregulation) associated with the rise of anti-inflammatory mediators. In this study we prospectively analyzed 52 consecutive patients with diagnosis of systemic inflammatory response syndrome (SIRS) at hospital admission to evaluate prognostic and early diagnostic performance of interleukin-10 (IL-10), soluble CD25 (sCD25) and interferon-γ (IFN-γ) and to confirm the prognostic accuracy of the sequential organ failure assessment (SOFA) score. METHODS: Patients were divided in two groups (group 1, n=28 patients with bacteremic SIRS and group 2, n=24 patients with non-bacteremic SIRS) and then stratified into survivors (n=39) and nonsurvivors (n=13). Serum markers were evaluated on the day of hospital admission (D-1) and on the 7th day of hospital stay (D-7). Concentration of sCD25 was evaluated by a sandwich ELISA kit. Levels of IL-10 and IFN-γ were quantified by a cytokine biochip array by the evidence investigator analyzer. Differences between groups were established by the Mann-Whitney test. Accuracy, sensitivity and specificity of diagnostic markers were evaluated by the receiver-operating characteristic curve analysis. Multivariate analysis was carried out to evaluate whether studied biomarkers are independent predictors of poor outcome in prognosis, and of bacteremic SIRS in diagnosis. RESULTS: IL-10, sCD25 and SOFA scores of survivors and nonsurvivors were significantly different both at D-1 (P=0.0014; P=0.014 and P=0.0311 respectively) and at D-7 (P=0.0002, P=0.014 and P=0.0012 respectively). Between the above groups IFN-γ level was significantly different only at D-7 (P=0.0013). Moreover IL-10 and sCD25 were significantly higher in bacteremic versus non-bacteremic SIRS patients at D-1 and at D-7 (P<0.05). IFN-γ values showed a significant decrease (P<0.05) in patients of group 1 only at D-7. The diagnostic accuracy of IL-10 and sCD25 was confirmed by the analysis of the AUROCC at D-1 and D-7 respectively. Multivariate analysis revealed that sCD25 and IL-10 are independent predictors of a poor outcome for our patients during the first day of hospital admission. CONCLUSIONS: IL-10 and sCD25 gave a significant contribution to prognostic evaluation and early diagnosis of bacteremic SIRS. SOFA score appeared to be a reliable prognostic tool in this subset of patients.

Six cases of sepsis caused by Pantoea agglomerans in a teaching hospital.

Pantoea agglomerans is an environmental organism which may seldom cause opportunistic infections. Here we report on a 6 case outbreak in a teaching hospital. Within three months . agglomerans was isolated from blood cultures of 5 patients from oncology and 1 patient from ICU departments. P. agglomerans was in pure culture in 5 cases, while in the last one Rahnella aquatilis and Candida famata were also isolated. Therefore, P. agglomerans is able to produce nosocomial infections in patients with primary pathology often associated with immune suppression.

An unusual case of brain abscess by Gemella morbillorum.

A case of deep brain abscess by Gemella morbillorum is described. Due to high fever, lethargy, severe headache, and the risk of intraventricular rupture of the suppurative lesion, a CT-guided stereotactic aspiration of the abscess was successfully performed. The patient responded well to a 6-week course of meropenem, metronidazole, and fluconazole. Gemella spp. should not be considered as trivial commensals of the mucous membranes, but appear as emerging pathogens involved in endocarditis, septic shock, and necrotizing pneumonia, as well as in serious intracranial infections.

Stenotrophomonas maltophilia lipopolysaccharide (LPS) and antibiotics: "in vitro" effects on inflammatory mediators.

Stenotrophomonas maltophilia is an emerging pathogen implicated in an increasing number of severe pulmonary infections and nosocomial sepsis. We evaluated the influence of four different antibiotics on the bacterial count and LPS activity found in broth cultures of S. maltophilia. After 4 h ceftazidime (CTZ) decreased live bacteria but increased endotoxin activity, whilst isepamicin (ISE), tobramycin (TB), and polymyxin B (PB) reduced both of them. We also investigated the influence of the above mentioned antibiotics on the ability of S. maltophilia culture filtrates and S. maltophilia LPS, extracted in our laboratory, to stimulate sepsis mediators such as tumor necrosis factor a (TNF-a), interleukin 8 (IL-8), interleukin 10 (IL-10), Nitric Oxide (NO) and as bactericidal/permeability-increasing protein (BPI) in human whole blood. Our results demonstrated that both single polycationic antibiotics and the combination of two molecules are able to kill bacteria and neutralize released S. maltophilia LPS. Combination between beta-lactams and aminoglycosides is often able to reduce the pro-inflammatory effects of S. maltophilia culture filtrates.

Multiple abscesses of the left brain hemisphere due to Listeria monocytogenes in an immunocompromised patient: a case report.

We describe a case of brain abscesses in a cirrhotic and diabetic 57-year-old woman showing fever, aphasia, right hemiparesis and seizures. Neuroradiological investigation revealed unilateral cerebritis evolving in multiple abscesses. From blood and surgical drainage samples Listeria monocytogenes grew in pure culture. Despite decompressive craniotomy, the patient died two months after hospital admission.

Phenotypic and genotypic evaluation of slime production by conventional and molecular microbiological techniques.

Twenty-nine staphylococcal isolates from different clinical samples were tested for slime production: phenotypic characterization was carried out using Christensen test (tube test) and Congo red agar plate test (CRA plate test), while the presence and expression of icaA and icaD genes were evaluated by real-time PCR. In 79.3% of studied strains there was a concordance between slime production and presence of icaA and icaD genes, and between lack of slime production and absence of both or only one of the tested genes. In four of five strains where positive phenotype was not associated with the presence of ica genes, gene co-expression (evaluated by mRNA determination) was lacking, while in only a case out of five, there was the presence of transcripts without phenotype. Our study, for the first time, introduces real-time PCR for the detection of both icaA and icaD genes and their mRNA and, furthermore, addresses the relationship between slime phenotype absence and mRNA expression, in clinical isolates of coagulase-negative staphylococci.