Cytosolic and Calcium-Independent Phospholipases A2 Activation and Prostaglandins E2 Are Associated with Escherichia coli-Induced Reduction of Insulin Secretion in INS-1E Cells.

It is suspected that microbial infections take part in the pathogenesis of diabetes mellitus type 1 (T1DM). Glucose-induced insulin secretion is accompanied by the release of free arachidonic acid (AA) mainly by cytosolic- and calcium independent phospholipases A2 (cPLA2 and iPLA2). Insulinoma cell line (INS-1E) was infected with E. coli isolated from the blood culture of a patient with sepsis. Invasion assay, Scanning Electron Microscopy and Transmission Electron Microscopy demonstrated the capacity of E. coli to enter cells, which was reduced by PLA2 inhibitors. Glucose-induced insulin secretion was significantly increased after acute infection (8h) but significantly decreased after chronic infection (72h). PLA2 activities, cPLA2, iPLA2, phospho-cPLA2, and COX-2 expressions were increased after acute and, even more, after chronic E. coli infection. The silencing of the two isoforms of PLA2s, with specific cPLA2- or iPLA2-siRNAs, reduced insulin secretion after acute infection and determined a rise in insulin release after chronic infection. Prostaglandins E2 (PGE2) production was significantly elevated in INS-1E after long-term E. coli infection and the restored insulin secretion in presence of L798106, a specific EP3 antagonist, and NS-398, a COX-2 inhibitor, and the reduction of insulin secretion in presence of sulprostone, a specific EP3 agonist, revealed their involvement in the effects triggered by bacterial infection. The results obtained demonstrated that cPLA2 and iPLA2 play a key role in insulin secretion process after E. coli infection. The high concentration of AA released is transformed into PGE2, which could be responsible for the reduced insulin secretion.

Infections of cardiovascular implantable electronic devices: 14 years of experience in an Italian hospital.

The aim of the study was to describe the microbial aetiology of infections from cardiovascular implantable electronic devices (CIEDs) between 2001 and 2014 at The Centro Cuore Morgagni Hospital (Catania, Italy). In this 14-year retrospective study on pacemaker isolates 1,366 patients were evaluated and clinical data were collected. CIEDs were analyzed and isolates tested by routine microbiological techniques. The presence of bacterial biofilm was assessed by means of scanning electron microscopy. Of the patients, fifty-three had catheter-related infections (3.9%), mainly resulting from Staphylococci (4 S. aureus, 32 S. epidermidis, 15 S. hominis, 3 S. haemolyticus, 1 S. warnerii, 1 S. schleiferi, 1 S. lentus and 1 S. capitis) that covered the cardiac catheter with biofilm. Overall, oxacillin-resistance was 55.1%, especially among S. epidermidis, while all isolates were susceptible to vancomycin, teicoplanin, tigecyclin, rifampin, trimethoprim/sulfamethoxazole, linezolid, moxifloxacin, tobramycin and gentamicin. Coagulase-negative staphylococci were the most frequently isolated and S. epidermidis was largely the main single agent. Only four Gram negatives caused polymicrobial infections with Staphylococci. Despite improvements in CIED design and implantation techniques, infection of cardiac devices remains a serious problem.

Involvement of PKCα-MAPK/ERK-phospholipase A(2) pathway in the Escherichia coli invasion of brain microvascular endothelial cells.

Escherichia coli K1 is the most common Gram-negative organism that causes neonatal meningitis following penetration of the blood-brain barrier. In the present study we demonstrated the involvement of cytosolic (cPLA(2)) and calcium-independent phospholipase A(2) (iPLA(2)) and the contribution of cyclooxygenase-2 products in E. coli invasion of microvascular endothelial cells. The traversal of bacteria did not determine trans-endothelial electrical resistance (TEER) and ZO-1 expression changes and was reduced by PLA(2)s siRNA. cPLA(2) and iPLA(2) enzyme activities and cPLA(2) phosphorylation were stimulated after E. coli incubation and were attenuated by PLA(2), PI3-K, ERK 1/2 inhibitors. Our results demonstrate the role of PKCα/ERK/MAPK signaling pathways in governing the E. coli penetration into the brain.

Chlamydia trachomatis prevalence in unselected infertile couples.

Chlamydia (C.) trachomatis, an obligate intracellular bacterium, is responsible for the most common sexual transmitted disease and infertility. The purpose of this study was to evaluate: a) the frequency of chlamydial infection in unselected infertile couples and b) whether chlamydial infection could be identified in the semen sample as effectively as in the urethral swab of infertile patients. To accomplish this, 73 unselected, consecutive infertile couples were enrolled. Both male and female partners underwent a complete work-up to identify the cause of their infertility. A PCR method was used to detect C. trachomatis in urethral swabs and the semen samples of the male partners and in the cervical swabs of the female partners. C. trachomatis infection was found in 6 couples (8.2%). Three couples had both partners infected, 2 couples had only the male partner infected, and 1 only the female partner. C. trachomatis infection was found in the urethral swab of all 5 men infected, whereas the bacterial DNA was found in the semen sample of 2 of them. These findings suggest that C. trachomatis infection is present in about 8% of unselected infertile couples and that the bacterium should be searched in the male partner urethral swab which has a higher sensitivity.

Bifidobacterium longum with fructo-oligosaccharide (FOS) treatment in minimal hepatic encephalopathy: a randomized, double-blind, placebo-controlled study.

Minimal hepatic encephalopathy (MHE) describes patients with chronic liver disease or cirrhosis who have no clinical symptoms of brain dysfunction but perform worse on psychometric tests compared with healthy subjects. The pathogenesis of hepatic encephalopathy is controversial although ammonia has been found to induce cerebral dysfunction. Increased intestinal ammonia production is due to bacterial urease activity and the production of other toxin methabolities, such as mercaptans, thioles. This study assesses the clinical efficacy of Bifidobacterium longum plus fructo-oligosaccharides (FOS) in the treatment of MHE. A total of 60 cirrhotic patients were randomly and equally divided into two groups receiving Bifidobacterium+FOS (17 males, 13 females; mean age, 46+/-11 years) or placebo (16 males, 14 females; mean age, 45+/-12 years), respectively. All patients underwent clinical and laboratory assessment psychometric tests and automated EEG analysis: neurophysiological assessment, liver function assessment, amd neuropsychological assessment. After 90 days of treatment, fasting NH(4) serum levels were significantly decreased (P=0.003), performance on Trail Making Test-A was significantly decreased (P=0.000), performance on Trail Making Test-B was significantly decreased (P=0.000), performance on the symbol digit modalities test was significantly improved (P<0.05), performance on block design was significantly improved (P=0.000), and performance on the MMSE test was significantly improved (P=0.000). We conclude that the improvement in biochemical and neuropsychological tests of the group treated with Bifidobacterium longum+FOS are interesting and merit further, close examination.