Diversity and persistence of MRSA and VRE in skilled nursing facilities: environmental screening, whole-genome sequencing and development of a dispersion index.

BACKGROUND: Environmental contamination with meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in skilled nursing facilities (SNFs) may contribute to patient acquisition. This study assessed diversity and association of MRSA and VRE isolates in an SNF wing, and developed a mathematical index to define the tendency of each strain to persist in rooms and spread horizontally. METHODS: This was a longitudinal study of MRSA and VRE colonization and contamination among successive patient occupancies in a cluster of nine SNF private rooms over 8 months, characterized by microbiological testing and whole-genome isolate typing. The 'dispersion index' of a strain was defined as the number of rooms in which it was found (including if it was found in the patient), divided by the average number of times it was found consecutively in the same room. FINDINGS: MRSA (10 strain types) and VRE (seven types) were recovered from the room or patient in 16.4% and 35.6% of the occupancies, respectively. MRSA showed moderate horizontal spread and several episodes of same-room persistence (three distinct strain types) (overall dispersion index 1.08). VRE showed a high tendency towards horizontal spread/new introductions (overall dispersion index 3.25) and only one confirmed episode of persistence. INTERPRETATION: The emerging picture of high diversity among contaminating strains and high likelihood of room persistence despite terminal cleaning (MRSA) and horizontal spread between rooms (VRE) in this setting calls for improved cleaning practices, heightened contact precautions and, most of all, establishment of individually tailored facility screening programmes to enable informed choices based on local, measurable and actionable epidemiologic parameters.

Leptin-based glycopeptide induces weight loss and simultaneously restores fertility in animal models.

AIM: To design, manufacture and test a second generation leptin receptor (ObR) agonist glycopeptide derivative. The major drawback to current experimental therapies involving leptin protein is the appearance of treatment resistance. Our novel peptidomimetic was tested for efficacy and lack of resistance induction in rodent models of obesity and appetite reduction. METHODS: The glycopeptide containing two additional non-proteinogenic amino acids was synthesized by standard solid-phase methods. Normal mice were fed with peanuts until their blood laboratory data and liver histology showed typical signs of obesity but not diabetes. The mice were treated with the peptidomimetic at 0.02, 0.1 or 0.5 mg/kg/day intraperitoneally side-by-side with 0.1 mg/kg/day leptin for 11 days. After termination of the assay, the blood cholesterol and glucose amounts were measured, the liver fat content was visualized and quantified and the remaining mice returned to normal diet and were allowed to mate. In parallel experiments normal rats were treated intranasally with the glycopeptide at 0.1 mg/kg/day for 10 days. RESULTS: The 12-residue glycosylated leptin-based peptidomimetic E1/6-amino-hexanoic acid (Aca) was designed to target a principal leptin/ObR-binding interface. E1/Aca induced leptin effects in ObR-positive cell lines at picomolar concentrations and readily crossed the blood-brain barrier (BBB) following intraperitoneal administration. The peptide initiated typical leptin-dependent signal transduction pathways both in the presence and absence of leptin protein. The peptide also reduced weight gain in mice fed with high-fat peanut diet in a dose-dependent manner. Obese mice receiving peptide E1/Aca at a 0.5 mg/kg/day dose lost weight, corresponding to a net 6.5% total body weight loss, while similar mice treated with leptin protein did not. Upon cessation of the weight loss treatment, several obesity-related pathologies (i.e. abnormal metabolic profile and liver histology as well as infertility) normalized in peptide-, but not leptin-treated, mice. Peptide E1/Aca added intranasally to growing normal rats decelerated normal weight gain corresponding to a net 6.8% net total body weight loss with statistical significance. CONCLUSIONS: No resistance induction to peptide E1/Aca or toxicity in either obese or healthy rodents was observed, indicating the potential for widespread utility of the peptidomimetic in the treatment of leptin-deficiency disorders. We provide additional proof for the hypothesis that difficulties in current leptin therapies reside at the BBB penetration stage, and we document that by either glycosylation or intranasal peptide administration we can overcome this limitation.

The antibacterial effect of a proline-rich antibacterial peptide A3-APO.

Antimicrobial resistance is an emerging worldwide concern in light of the widespread antimicrobial drug use in humans, livestock and companion animals. The treatment of life-threatening infections is especially problematic because clinical strains rapidly acquire multiple-drug resistance. Antimicrobial peptides have long been considered to be viable alternatives to small molecule antibiotics. However, the peptides' parenteral use is frequently hampered by inadequate safety margins and rapid renal clearance leaving them suitable only for topical applications. The proline-rich peptide A3-APO represents a family of a new class of synthetic dimers that kill bacteria by a dual mode of action and carry domains for interaction with both the bacterial membrane and an intracellular target. From a series of designer antibacterial peptides, A3-APO emerged as a viable preclinical candidate by virtue of its superior ability to disintegrate the bacterial membrane, inhibit the 70-kDa heat shock protein DnaK alone or in synergy with small molecule antibiotics, lack of eukaryotic toxicity and withstand proteolytic degradation in body fluids. As many other proline-rich peptides, A3-APO binds to the C-terminal helical lid of bacterial DnaK and inhibits chaperone-assisted protein folding in bacteria but not in mammalian Hsp70. In this review, the structure, pharmacokinetic properties, antimicrobial spectrum of peptide A3-APO and its in vivo metabolite are summarized and the in vitro and in vivo antimicrobial effects (antimicrobial susceptibilities, postantibiotic effects, resistance induction) are discussed in detail.

Targeted therapy for advanced prostate cancer: Looking through new lenses.

Prostate cancer is the most common noncutaneous malignancy in men and also the third leading cause of death due to cancer in males. The conventional initial therapy for localized advanced or metastatic disease is hormone or androgen deprivation therapy. Although hormone-based therapies generally result in rapid responses, the disease then progresses to a phase when they fail to control the malignancy despite castrate testosterone levels. Some patients with castration-resistant prostate cancer continue to respond to secondary hormonal manipulations, and docetaxel-based chemotherapy improves median survival to about 18 months. Prostate cancer is termed hormone-refractory when it no longer responds to hormonal therapy. Currently, other therapeutic options, such as radical prostatectomy, radiation therapy or cryotherapy offer improvement in survival mostly in early stages. New therapy approaches based on a deeper understanding of especially metastatic prostate cancer are of vital importance. Here we discuss up-to-date clinical trials of agents with novel targets and present paradigms in prostate cancer vaccine therapy, metastasis suppressor genes, and some provocative findings on combination therapies of cytotoxic agents, which might provide a platform for developing effective treatment for advanced prostate cancer.

Personalizing gene therapy in gastric cancer.

Gene therapy was proposed many decades ago as a more straightforward and definitive way of curing human diseases, but only recently technical advancements and improved knowledge have allowed its active development as a broad and promising research field. After the first successes in the cure of genetic and infectious diseases, it has been actively investigated as a means to decrease the burden and suffering generated by cancer. The field of gastric cancer is witnessing an impressive flourishing of studies testing the possibilities and actual efficacy of the many different strategies employed in gene therapy, and overall results seem to be two-sided: while original ideas and innovative protocols are providing extremely interesting contributions with great potential, more advanced-phase studies concluded so far have fallen short of expectations regarding efficacy, although invariably demonstrating little or no toxicity. An overview of the major efforts in this field is provided here, and a critical discussion is presented on the single strategies undertaken and on the overall balance between potentiality and pitfalls.

Activity of moxifloxacin in combination with vancomycin or teicoplanin against Staphylococcus aureus isolated from device-associated infections unresponsive to glycopeptide therapy.

We tested the in vitro bactericidal activity of moxifloxacin, a new 8-methoxyquinolone, alone and in combination with vancomycin or teicoplanin at different multiples of minimum inhibitory concentration (MIC) against 8 methicillin-ciprofloxacin-resistant Staphylococcus aureus (M-C-RSA) and 1 methicillin-ciprofloxacin susceptible S. aureus (M-C-SSA) recently isolated from device-associated infections unresponsive to or relapsing after glycopeptide therapy, despite device removal. MICs of vancomycin ranged from 1 to 4 microg/ml, MICs of teicoplanin ranged from 2 to 8 microg/ml; MICs of moxifloxacin were always 2 microg/ml against M-C-RSA isolates and 0.125 microg/ml against the M-C-SSA isolate. The 9 strains resulted tolerant when tested for vancomycin, teicoplanin, and moxifloxacin used alone at 2 x MIC. In all cases the combination of moxifloxacin and teicoplanin or vancomycin appeared to be bactericidal already at MIC concentration for glycopeptides plus 0.5 x MIC concentration for moxifloxacin. If these results are confirmed in vivo in animal experiments, the combination of moxifloxacin with glycopeptides might be useful for treating device-associated infections, and in preventing the frightening phenomenon of increasing MICs for glycopeptides.

Conservative medical therapy of infections following osteosynthesis: a retrospective analysis of a six-year experience.

The conventional therapeutic approach to bone infection associated with osteosynthesis is based on the idea that microbial eradication is most readily achieved by removal of the foreign material together with adequate antimicrobial therapy. This strategy usually requires implantation of external fixation devices with additional discomfort to the patient. We report our experience with conservative medical and antimicrobial therapy without removal of the osteosynthesis until adequate bone callus deposition is documented by bone radiography scan. Twenty patients with infections associated with intramedullary nailing (9 patients), screws and plate (9 patients) or screws (2 patients) were treated between 1995 to 2000. Osteosynthesis implantation sites were tibia (7 patients), femur (6 patients), femur and tibia (1 patient), humerus (1 patient), others (5 patients). Diagnosis of infection was based on clinical-microbiological evidence and confirmed by 99Tc-labeled leukocyte scan studies. Offending pathogens were Staphylococcus aureus 17 cases, Staphylococcus aureus + Escherichia coli, Staphylococcus epidermidis, unknown, 1 case each. Most infections were initially treated with intravenous or intramuscular teicoplanin +/- ciprofloxacin or rifampin followed by oral antimicrobial therapy usually with ciprofloxacin or minocycline plus rifampin. Mean duration of antimicrobial therapy was 27.7 weeks (range 12-64 weeks). All patients (100%) were cured, and none complained of side-effects requiring antibiotic therapy discontinuation. We conclude that conservative medical therapy is feasible for osteosynthesis-associated bone infection.

Priming effects of substance P on calcium changes evoked by interleukin-8 in human neutrophils.

The neurokinin (NK) substance P (SP), which is a mediator of neurogenic inflammation, has been reported to prime human polymorphonuclear neutrophils (PMNs). The priming effects of SP on PMNs activated by recombinant interleukin-8 (rIL-8) were investigated. SP enhanced, in a dose- and time-dependent way, the rise in cytosolic free-calcium concentration, [Ca(2+)]i, evoked by the chemokine. The priming effects of SP were abolished by exposing PMNs to a calcium-free medium supplemented with EGTA. The C-terminal peptides SP(4-11) and SP(6-11) but not the N-terminal peptide SP(1-7) shared the priming effects of SP. The selective NK-1 receptor agonist [Sar-9, MetO2-11]SP mimicked the effects of SP, which were not reproduced by the selective NK-2 receptor agonist [betaAla-8]-NKA(4-10) or the selective NK-3 agonist senktide. Two selective NK-1 antagonists, CP96,345 and L703,606, dose dependently inhibited SP priming effects. These results demonstrated that SP primes PMNs exposed to rIL-8 and suggested that SP priming effects are receptor mediated.

Prosthetic biologic valve endocarditis caused by a vancomycin-resistant (vanA) Enterococcus faecalis: case report.

We recently observed (February 1999) a 68-year old patient with endocarditis on a prosthetic biologic valve caused by a vancomycin-resistant Enterococcus faecalis. Broth dilution tests showed susceptibility to ampicillin (MIC=0.5 microg/ml), no high resistance to aminoglycosides (MIC for gentamicin <500 microg/ml) and resistance to vancomycin (MIC >256 microg/ml) and teicoplanin (MIC >16 microg/ml). A PCR assay detected vanA gene in this strain. A transthoracic echocardiogram did not show valvular vegetations. A possible endocarditis was diagnosed and the patient received ampicillin for 8 weeks and gentamicin for 6 weeks. The patient remained afebrile after a 4-month follow-up when he underwent surgical replacement of the dysfunctional bioprosthetic valve. Mitral valve was sterile on culture, but histology confirmed the diagnosis of previous endocarditis. This is the third case of endocarditis caused by vancomycin-resistant E. faecalis reported to date.

Comparative in-vitro activity of moxifloxacin, penicillin, ceftriaxone and ciprofloxacin against pneumococci isolated from meningitis.

Minimum inhibitory concentrations of penicillin, ceftriaxone, ciprofloxacin, and moxifloxacin (BAY 12-8039), a new 8-methoxyquinolone, were determined for 60 cerebrospinal fluid isolates of Streptococcus pneumoniae collected during January 1997-April 1998 at Italian medical centres. Three reference isolates with predetermined MIC values (two penicillin- and multidrug-resistant isolates, one uniformly susceptible to all antibiotics) were also tested with the same antibiotics. The MIC90 of penicillin was < or = 0.03 mg/L (range < or = 0.03-2 mg/L), of ceftriaxone 0.06 mg/L (range < or = 0.03-0.5 mg/L), of ciprofloxacin 2 mg/L (range 0.5-8 mg/L) and of moxifloxacin 0.06 mg/L (range 0.03-0.12 mg/L). Moxifloxacin was effective against all the penicillin-resistant isolates tested, with an MIC of 0.06 mg/L. Moxifloxacin was 32-fold more active than ciprofloxacin and was not affected by penicillin and cephalosporin resistance. These results indicate that moxifloxacin could be useful for the treatment of both penicillin-sensitive and -resistant S. pneumoniae meningitis.

Fatal suppurative mesenteric thrombophlebitis caused by an Enterococcus faecalis highly resistant to aminoglycosides: case report.

A 56-year old man with non-Hodgkin's lymphoma and biliary tract endoprosthesis, developed chronic bacteremia caused by Enterococcus faecalis with high-level resistance to gentamicin and streptomycin. The sources of bacteremia were a device-associated biliary tract infection, a suppurative thrombophlebitis of the confluence of the superior mesenteric vein with the splenic vein as well as multiple liver and pancreatic abscesses. Despite antibiotic therapy and multiple drainages of abscesses, the patient died due to overwhelming infection.

In vitro susceptibility of Staphylococcus aureus isolated from blood to currently used antistaphylococcal drugs.

Changes in antibiotic susceptibility was evaluated in 77 consecutive nosocomial clinical isolates of Staphylococcus aureus collected from 1986 to 1994 at the Umberto I Polyclinic of the University of Rome (63 isolates) and from 7 other Roman hospitals (14 isolates). Oxacillin resistance in these isolates increased from 39% during the 1980s to 69% during the 1990s. Significant increases in resistance to ciprofloxacin, clindamycin and rifampicin were observed among oxacillin-resistant strains. No resistance to glycopeptides was observed although both teicoplanin and vancomycin had slightly reduced antistaphylococcal activity.

Studies on the in vitro inversion of flurbiprofen.

This paper reports in vitro studies on the metabolic inversion of flurbiprofen (FL), an arylpropionic acid antiinflammatory agent (2-APA). The inversion was studied with both rac-FL and R-FL, by incubation with rat hepatic microsomes, in the presence of either CoASH and ATP or NADPH. The two isomers of the drug were separated as their (+)-(R)-1-phenylethylamides by direct phase high-performance liquid chromatography on a silica gel column with an achiral mobile phase. The inversion was more pronounced in the presence of CoASH and ATP for both the racemate and the R-isomer, which supports the key role of CoA thioesters in the metabolic inversion of profens. The inversion observed in the presence of NADPH suggests that, when the incubation is run with hepatic microsomes, a CYP450-mediated pathway is also active. In order to get more insight into the CYP450-mediated inversion pathway, we studied the effect of irradiating microsomes with a low dose of He-Ne laser radiation (0.2 J). Such irradiation caused a significant increase in inversion at all times studied and normalized the anomalous value of inversion observed at 15 min in this pathway.

[Idiopathic CD4+ T-lymphocyte deficiency: the clinical evolution of a case]. / Deficit idiopatico di linfociti T CD4+: evoluzione clinica di un caso.

The case of a patient with Salmonella arizonae sepsis, esophageal candidiasis, and a low CD4+ T lymphocyte count is presented. Follow-up continued for over 2 years after the patient was discharged from the hospital, and his clinical course and clinical-immunological examinations are described. After a period of several years during which the patient had recurrent acute infectious episodes, he improved markedly after cholecystectomy and toilette of the gingival inlets for severe parodontopathy. His CD4+ T cell count increased although it remained below normal values. This case points to possible hypothesis that chronic infective foci may further compromise the immune system when a congenital functional or numerical CD4+ T cell deficit is present.

Insulin stimulates endothelin-1 secretion from human endothelial cells and modulates its circulating levels in vivo.

Endothelin-1 (ET-1) is a potent vasoactive and mitogenic peptide produced by the vascular endothelium. In this study, we evaluated whether insulin stimulates ET-1 secretion by human endothelial cells derived from umbilical cord veins and by human permanent endothelial hybrid cells Ea.hy 926. Moreover, to provide evidence that insulin may stimulate ET-1 secretion in vivo, plasma ET-1 levels were evaluated in 7 type II diabetic normotensive males (mean age, 54.3 +/- 4.0 yr) during 2-h hyperinsulinemic euglycemic clamps (287 pmol insulin/m2.min-1) as well as in 12 obese hypertensive males (mean age, 44.2 +/- 4.6 yr) before and after a 12-week period of caloric restriction. Our results showed that insulin stimulated ET-1 release from cultured endothelial cells in a dose-dependent fashion. ET-1 release persisted for 24 h and was also observed at physiological insulin concentrations (10(-9) mol/L). The insulin-induced ET-1 secretion was inhibited by genistein, a tyrosine kinase inhibitor, and by cycloheximide, a protein synthesis inhibitor, suggesting that it requires de novo protein synthesis rather than ET-1 release from intracellular stores. In the in vivo experiments, plasma ET-1 levels rapidly increased during euglycemic hyperinsulinemic clamps (from 0.76 +/- 0.18 pg/mL at time zero to 1.65 +/- 0.21 pg/mL at 60 min; P < 0.05) and persisted elevated until the end of insulin infusion (1.37 +/- 0.37 pg/mL at 120 min; P < 0.05 vs. time zero). In obese hypertensives, plasma ET-1 levels significantly decreased after 12 weeks of caloric restriction (from 0.85 +/- 0.51 to 0.48 +/- 0.28 pg/mL; P < 0.04). The decrease in body weight induced by caloric restriction was accompanied by a significant reduction in fasting insulin levels (from 167.2 +/- 94.0 to 98.9 +/- 44.9 pmol/L; P < 0.05) which correlated with the reduction in plasma ET-1 levels (r = 0.78; P < 0.003). In conclusion, our data show that insulin stimulates both in vitro and in vivo ET-1 secretion. Such interaction could play a significant role in the development of atherosclerotic lesions in hyperinsulinemic conditions.

Effect of in vivo He-Ne laser irradiation on biogenic amine levels in rat brain.

In order to elucidate the metabolic modifications induced in rat brain by low power He-Ne laser irradiation in vivo, the variations in the biogenic amine levels in cortex, striatum and hippocampus were studied. Noradrenaline (NA), dopamine (DA) and serotonin (5-HT) were evaluated by HPLC-EC on irradiated rats, untreated rats (controls) and rats which had undergone restraint stress (stressed). The results obtained on groups of four to eight rats assayed individually showed that irradiation caused a strong increase in 5-HT in striatum and hippocampus, a small but significant decrease in NA in cortex, and DA levels were not significantly affected. Restraint stress per se led to a considerable decrease in 5-HT and DA in striatum and hippocampus, but did not significantly alter the NA levels.

Rat brain metabolism enzyme activity variations following He-Ne laser irradiation.

In order to gain insight into the metabolic modifications induced in rat brain tissues by helium-neon (He-Ne) laser irradiation, in the research described here, we investigated the variations in the activity of the enzymes aspartate transferase (AST, EC 2.6.1.4), both cytosolic and mitochondrial, glutamate dehydrogenase (GIDH, EC 1.4.1.3), and total superoxide dismutase (SOD, EC 1.15.1.1), in the brain of rats treated with a very small dose (1.08 J) of He-Ne laser radiation. The rats were sacrificed 4 h after the treatment. The enzymes were evaluated spectrophotometrically in brain extracts of irradiated animals and also in untreated rats (controls) and rats that underwent simulated treatment (stressed). The data obtained from 5-10 animals assayed individually showed that, in the in toto brain tissues of the irradiated rats compared to the stressed rats, there was a marked increase of total SOD, together with an appreciable decrease of cytosolic AST, and insignificant variations in mitochondrial AST and GIDH. Stress alone caused a considerable decrease of total SOD and small but statistically significant increases of s-AST, m-AST, and GIDH.

Effects of combinations of arecoline and atropine on mouse motor activity.

1. Effects on motor activity were studied after acute administration of arecoline, atropine alone and in combination in the mouse. 2. Atropine from 15 to 45 mg/kg increased motor activity. 3. A reduction in activity was observed at doses of arecoline above 0.2 mg/kg. 4. An antagonism between arecoline and atropine was observed only at low doses of arecoline, while higher doses of arecoline in association with atropine increased activity.

Action of a chronic arecoline administration on mouse motility and on acetylcholine concentrations in the CNS.

The modifications of mouse motility and of the levels of acetylcholine (ACh) in two sections of the CNS caused by a chronic administration of 4.5; 9.5; 28.5 and 60 mg kg-1 day-1 of arecoline for 20 days have been studied. At low doses (4.5 and 9.5 mg kg-1 day-1), arecoline caused no modification of the ACh levels and of the motility. The higher doses (28.5 and 60 mg kg-1 day-1) caused a reduction of the mouse motility and an increase of the ACh levels in the subcortical structures of the CNS of the mouse.