Genomic-wide analysis approach revealed genomic similarity for environmental Mexican S. Oranienburg genomes.

As the human population grows, an increase in food trade is needed. This elevates the risk of epidemiological outbreaks. One of the prevalent pathogens associated with food production in Mexico has been Salmonella Oranienburg. Effective surveillance systems require microbial genetic knowledge. The objective of this work is to describe the genetic composition of Mexican S. Oranienburg genomes. For that, 53 strains from different environmental sources were isolated and sequenced. Additionally, 109 S. Oranienburg genomes were downloaded. Bioinformatic analyses were used to explore the clonal complex and genomic relatedness. A major clonal group formed by ST23 was identified comprising four STs. 202 SNPs were found the maximum difference among isolates. Virulence genes for host invasion and colonization as rpoS, fimbria type 1, and, T3SS were found common for all isolates. This study suggests that Mexican S. Oranienburg strains are potential pathogens circulating continuously in the region between host and non-host environments.

Bacteriophage applications for fresh produce food safety.

Foodborne illnesses, mainly bacteria, are a major cause of morbidity and mortality worldwide. Pathogenic bacteria are involved in almost every step within the fresh produce chain compromising the companies' food safety programs and generating an ascending number of foodborne outbreaks in various regions of the world. Recently, bacteriophages return to the status of biocontrol agents. These bacteria-killing viruses are able to reduce or eliminate pathogenic bacterial load from raw and ready to eat foods. Phages are efficient, strain specific, easy to isolate and manipulate, and for that reasons, they have been used in pre and post harvest processes alone or mixed with antimicrobial agents for biocontrolling pathogenic bacteria. In this review, we focused on the feasibility of using lytic bacteriophage on fresh fruits and vegetables industry, considering challenges and perspectives mainly at industrial production level (packinghouses, supermarkets), where high volume of phage preparations and consequently high costs may be required.

Detection of pathogenic micro-organisms on children's hands and toys during play.

AIMS: This study aimed to determine if the children's leisure activities impact the presence of pathogens on their hands and toys. METHODS & RESULTS: To assess the microbiological hazard in playground areas, a pilot study that included 12 children was conducted. We then conducted an intervention study; children's hands and toys were washed before playing. Faecal coliforms, pathogenic bacteria and Giardia lamblia were quantified by membrane filtration, selective media and flotation techniques, respectively; rotavirus, hepatitis A and rhinovirus by RT-PCR. Pilot study results revealed faecal contamination on children's hands and toys after playing on sidewalks and in public parks. Pathogenic bacteria, hepatitis A and G. lamblia on children's hands were also found. In the intervention study, Staphylococcus aureus and Klebsiella pneumoniae were found on children's hands at concentrations up to 2·5 × 10(4) and 1 × 10(4) CFU hands(-1), respectively. E. coli and Kl. pneumoniae were detected on toys (2·4 × 10(3) and 2·7 × 10(4) CFU toy(-1), respectively). Salmonella spp, Serratia spp and G. lamblia cysts were also present on toys. CONCLUSION: Children's play activities influence microbial presence on hands and toys; the transfer seems to occur in both ways. SIGNIFICANCE AND IMPACT OF THE STUDY: Control strategy needs to be implemented to protect children from infectious diseases.

Irrigation water quality and the benefits of implementing good agricultural practices during tomato (Lycopersicum esculentum) production.

The implementation of good agricultural practices (GAP) from irrigation water to the tomato packaging process enhances the safety of fresh produce and its value throughout the food chain. The aim of the present study was to show that fresh produce farms that apply and enforce GAP could reduce the presence of Salmonella in finished produce. Samples were collected biweekly from six packing houses from the central region of Sinaloa, México, for the isolation of Salmonella spp by the ISO 6579:2002 method, and the isolated strains were serotyped and genotyped by the Kauffmman-White scheme and pulsed field gel electrophoresis (PFGE), respectively. Salmonella strains were detected in 13 (36.1 %) irrigation water samples, while only two tomato samples were positive (5.5 %). Eight different serotypes were identified in irrigation water, and Salmonella Oranienburg (34 %) was the most prevalent; however, only Salmonella Agona and Salmonella Weltevreden were present on tomatoes. Salmonella Oranienburg was the most widely dispersed and variable serotype, with 10 different PFGE profiles. Salmonella Weltevreden was isolated from both types of samples, albeit with distinct genetic profiles, implying that the sources of contamination differ. These results confirm the utility of implementing good agricultural practices to reduce Salmonella contamination in irrigation water and the packaging process.

Impact of prescribed cleaning and disinfectant use on microbial contamination in the home.

AIMS: To identify and quantify the presence of Escherichia coli, Staphylococcus aureus, Salmonella, hepatitis A and norovirus in households and to assess the effect of chlorine and quaternary ammonium-based disinfectants following a prescribed use. METHODS AND RESULTS: Eleven sites distributed in kitchen, bathroom, pet and children's areas of two groups of 30 homes each: (i) a nonprescribed disinfectant user group and (ii) a disinfectant protocol user group. During the 6-week study, samples were collected once a week except for week one when sample collection occurred immediately before and after disinfectant application to evaluate the disinfectant protocol. The concentration and occurrence of bacteria were less in the households with prescribed use of disinfectants. The greatest reductions were for E. coli (99%) and Staph. aureus (99·9999%), respectively. Only two samples were positive for HAV, while norovirus was absent. Disinfection protocols resulted in a significant (P < 0·05) microbial reduction in all areas of the homes tested compared to homes not using a prescribed protocol. CONCLUSIONS: The study suggests that disinfectant product application under specific protocol is necessary to achieve greater microbial reductions. SIGNIFICANCE AND IMPACT OF THE STUDY: Prescribed protocols constitute an important tool to reduce the occurrence of potential disease-causing micro-organisms in households.

Biomechanical response of the CNS is associated with frailty in NPH-suspected patients.

Frailty is known to predict dementia. However, its link with neurodegenerative alterations of the central nervous system (CNS) is not well understood at present. We investigated the association between the biomechanical response of the CNS and frailty in older adults suspected of normal pressure hydrocephalus (NPH) presenting with markers of multiple co-existing pathologies. The biomechanical response of the CNS was characterized by the CNS elastance coefficient inferred from phase contrast magnetic resonance imaging and intracranial pressure monitoring during a lumbar infusion test. Frailty was assessed with an index of health deficit accumulation. We found a significant association between the CNS elastance coefficient and frailty, with an effect size comparable to that between frailty and age, the latter being the strongest known risk factor for frailty. Results were independent of CSF dynamics, showing that they are not specific to the NPH neuropathological condition. The CNS biomechanical characterization may help to understand how frailty is related to neurodegeneration and detect the shift from normal to pathological brain ageing.

Electron beam irradiated UHMWPE: degrading action of air and hyaluronic acid.

Ultra high molecular weight polyethylene, both pure and electron beam irradiated, was exposed to air and hyaluronic acid. Physical and mechanical analyses were performed in order to check the polymeric change due to the treatment. Pure UHMWPE, in fact, was modified by the hyaluronic acid that plasticizes the polymer. The electron irradiation cross links the chains and prevents their sliding in acid presence. A low irradiation dose is preferable rather than an high one. Low doses induce low amount of free radicals, witch react with oxygen and hyaluronic acid inducing low polymer degrade maintaining the initial mechanical performance. High doses degrade significantly the polymer properties.100 kGy irradiation in air can be applicable on the polyethylene as well as a compromise between the low mechanical performance improving and the material degradation.

Nascent teichoic acids insertion into the cell wall directs the localization and activity of the major pneumococcal autolysin LytA.

The bacterial cell wall is in part composed of the peptidoglycan (PG) layer that maintains the cell shape and sustains the basic cellular processes of growth and division. The cell wall of Gram-positive bacteria also carries teichoic acids (TAs). In this work, we investigated how TAs contribute to the structuration of the PG network through the modulation of PG hydrolytic enzymes in the context of the Gram-positive Streptococcus pneumoniae bacterium. Pneumococcal TAs are decorated by phosphorylcholine residues which serve as anchors for the Choline-Binding Proteins, some of them acting as PG hydrolases, like the major autolysin LytA. Their binding is non covalent and reversible, a property that allows easy manipulation of the system. In this work, we show that the release of LytA occurs independently from its amidase activity. Furthermore, LytA fused to GFP was expressed in pneumococcal cells and showed different localization patterns according to the growth phase. Importantly, we demonstrate that TAs modulate the enzymatic activity of LytA since a low level of TAs present at the cell surface triggers LytA sensitivity in growing pneumococcal cells. We previously developed a method to label nascent TAs in live cells revealing that the insertion of TAs into the cell wall occurs at the mid-cell. In conclusion, we demonstrate that nascent TAs inserted in the cell wall at the division site are the specific receptors of LytA, tuning in this way the positioning of LytA at the appropriate place at the cell surface.

Mechanical behavior of quartz fiber reinforced epoxy resins for teeth restoration.

In this work composite materials, based on quartz fibers and epoxy resins, were employed with the aim to restore damaged teeth. The composite materials were chosen because they show biomechanical features very similar to that of the dentine, the main constituent of the tooth. Extracted teeth were rebuilt with two different restorative procedures: in the first, the composite material was pre-formed in a conical trunk shape abutment (PA) and then bonded to a fiber quartz post with a dental bonder. In the second rebuilt system the abutment was prepared by cross linking the resin on the fiber quartz post with a halogen lamp (CRA). The restored teeth were then mechanically tested and observed with a Scanning Electron Microscope (SEM) with the aim to study the interaction between the reconstructive materials. Wetting and roughness measurements were also carried out in order to study the interface adhesion between the post and the abutments. Characterization analysis evidenced that the CRA restorative procedure improves the adhesion between the substitutive materials and shows higher fracture strength than the PA ones. Anyway both the rebuilt systems are able to support the masticator load. An explanation of the interfacial post-abutment interaction phenomenon is discussed.

Serum intercellular adhesion molecule-1 and long-term response to IFN-alpha2b therapy in chronic hepatitis C.

We have attempted to correlate the outcome of interferon (IFN) therapy with circulating soluble intercellular adhesion molecule-1 (sICAM-1) and the level of viremia in a sample of patients with chronic hepatitis C virus (HCV) infection. Forty-two patients were studied. Eighteen patients were maintained in long-term remission following IFN therapy, whereas 24 did not respond or relapsed. Serum concentrations of sICAM-1 were measured by enzyme-linked immunoassay. Viremia was measured by branched DNA signal amplification assay. Basal sICAM-1 was significantly higher in long-term responders than in nonresponder/relapsing patients. It was found that very high levels (>1000 ng/ml) were closely associated with long-term clinical response. A quantitative evaluation of viremia in basal conditions, which was significantly lower in long-term responders, gave completely opposite results. During treatment, sICAM-1 concentrations significantly decreased in the group of long-term responders but not in the nonresponders. sICAM-1 reduction was apparent as early as 1 month after treatment started. Serum sICAM-1 may be a useful parameter in evaluating the outcome of patients with chronic hepatitis C infection treated with IFN.

HCV-RNA levels play an important role independently of genotype in predicting response to interferon therapy.

OBJECTIVE: To evaluate the relationship between hepatitis C virus (HCV)-RNA levels and genotypes in order to establish their potentially predictive role in interferon (IFN) response. DESIGN: To detect HCV genotype at baseline and HCV viraemia levels before and during IFN treatment in three groups of patients with different IFN response. METHODS: Our study included 85 patients with biopsy-proven chronic hepatitis C who underwent IFN therapy at standard schedule (3 MU thrice weekly for 6 months). On the basis of IFN response they were subdivided into three groups as follows: non responders (NR: 27 cases) when alanine aminotransferase (ALT) values (normal value: 0-40 IU) at the end of treatment were abnormal (101.7 +/- 10.4); responders relapsing (RR: 29 cases) when normal ALT values at the end of therapy (28.14 +/- 1.7) increased during follow-up; sustained (long-term) responders (LTR: 29 cases) when ALT values remained normal for at least 12 months of follow-up (ALT values at the end of therapy: 21.8 +/- 1.4). ALT activity was monitored monthly during therapy and each month during 12 months of follow-up. HCV genotype was evaluated before starting treatment whereas HCV-RNA viraemia was checked at baseline and at the 1st and 6th months of therapy. RESULTS: The baseline viral load was higher in the NR group than in the RR and LTR groups independently of genotype; HCV-RNA levels progressively decreased during therapy independently of response but the levels remained significantly higher in the NR group. Genotype 1b was prevalent in the NR group. However, levels of viraemia in genotype 1b LTR patients are significantly lower than in genotype 1b NR patients. CONCLUSION: These results suggest that among viral-related parameters viraemia alone seems to play an important role in predicting response to IFN independently of genotype.

Interferon retreatment in chronic hepatitis C: which patients to choose, and what schedule to use.

UNLABELLED: OBJECTIVE; To evaluate the results of a large cohort of non-responder or relapsing responder patients with chronic hepatitis C retreated with various schedules of interferon (IFN). METHODS: Our study included 276 patients (158 non-responders and 118 relapsing responders) who underwent IFN retreatments. Among the non-responder group, 158 patients underwent further courses of IFN. In particular, 108 patients underwent one course of IFN retreatment, 40 patients underwent two courses, eight patients underwent three courses, and two patients underwent four courses. Regarding the relapsing responder group, the 118 patients were retreated with the same dosage for varying periods. In particular, 50 patients were treated for 6 months, 43 patients for 12 months, and 25 for 24 months. Patients in the subgroups of IFN retreatment were homogeneous as far as age and gender distribution, as well as virological and histological characteristics, are concerned. Qualitative and quantitative HCV-RNA was evaluated at baseline, at the end of treatment and at the last check-up of follow-up. HCV genotype was determined on baseline serum samples. Alanine transaminase (ALT) levels were tested monthly. RESULTS: Long-term biochemical (normal ALT levels) and virological (HCV-RNA negative) response was obtained in 2.6% of non-responder retreated patients, and in 33.9% of relapsing responder retreated patients. Evaluation of response on the basis of the duration of treatment showed that 48%, 19% and 16% of relapsing responder patients retreated for 24, 12 and 6 months, respectively, obtained long-term biochemical and virological response. CONCLUSION: Non-responder patient retreatment is inefficient especially in cirrhotic and/or genotype 1 b patients. IFN retreatment is warranted in relapsing responder patients. In particular, 24-month therapy induces significant long-term biochemical and virological response.

Serum lamivudine levels in the presence of a lamivudine-resistant HBV mutant.

BACKGROUND/AIMS: Lamivudine efficiently inhibits hepatitis B virus replication and has been used to treat hepatitis B virus recurrence after orthotopic liver transplantation. Although effective, its use is hampered by viral breakthrough due to the appearance of hepatitis B virus drug-resistant strains. Aims of this work were to evaluate the inter- and intra-individual variations of lamivudine serum levels and the effects on the drug levels of the lamivudine-resistant hepatitis B virus mutant infection. METHODS: Serum lamivudine concentration was measured by high-performance liquid chromatography. Polymerase chain reaction analysis and sequencing analysis of the reverse transcriptase area of the polymerase was performed on each sample using specific primers. A polymerase chain reaction-enzyme-linked immunosorbent assay was used to differentiate between wild-type hepatitis B virus and lamivudine-resistant hepatitis B virus strain. RESULTS: Lamivudine serum levels presented minor inter- and intra-individual fluctuations along time, with an important increase at the time of the hepatitis flare-up due to the hepatitis B virus mutant presence. When the wild-type hepatitis B virus briefly reappeared as a mixed population, the titre of lamivudine dropped to below the detection level. CONCLUSIONS: While lamivudine serum levels appears stable when the anti-viral efficacy is fully achieved, important fluctuations are present according to the type of viral population, with a considerable decrease possibly due to the presence of the wild-type virus.

Continence in patients who undergo posterior rectal flap anorectoplasty.

PURPOSE: The authors report the postoperative follow-up results of patients who underwent posterior rectal flap anorectoplasty (PRFA), with emphasis in fecal continence. Variables considered on each patient were sex, presence of fistula, location of the fistula, severity of the defect during the correction, sacral condition, dysraphism, and age at surgery. METHODS: Continence was rated using the Peña method and defecogram. The authors studied 20 patients (17 boys and three girls). RESULTS: Postoperatively, normal continence was found in 18 patients. Of the two remaining (boys), one had grade II spotting (sacrum agenesia and uretrobulbar fistula) and the other had grade II staining; this patient had the most severe malformation requiring an abdominoperineal approach. All of the defecograms showed complete emptying of the rectum. No recurrent fistulas occurred. CONCLUSIONS: The posterior rectal flap anorectoplasty is a new technique that takes into consideration all known factors that contribute to continence. This initial report confirms that this technique results in excellent continence for patients with imperforate anus.

Hepatitis G virus infection in intravenous drug users with or without human immunodeficiency virus infection.

BACKGROUND/AIMS: To evaluate the HGV infection prevalence in a group of intravenous drug users with or without human immunodeficiency virus coinfection. METHODOLOGY: We studied 57 patients (48 males and 9 females) who were either previous or still ongoing intravenous drug users. Thirty-seven patients were HIV+ve, 55 patients were anti-HCV+ve and 3 patients were HBsAg chronic carriers. Patient sera were tested for HGV-RNA, anti-E2, qualitative and quantitative HCV-RNA as well as for HCV genotypes. Moreover, the ALT level was checked in the serum sample of each patient. RESULTS: We found a high prevalence (35/57; 61.4%) of HGV infection in our patients. HGV-RNA was detected in 16 out of the 57 intravenous drug users (28%). In particular HGV-RNA was positive in 12 out of the 37 HIV+ve patients (32.4%) and in 4 out of the 20 HIV-ve patients (20%). Anti-E2 were detected in 19 out of the 57 patients (33.3%) with greater prevalence among HIV-ve subjects (12/20; 60%) compared to HIV+ve group (7/37; 18.9%). This resulting difference was statistically significant (P < 0.05). All HGV-RNA+ve/anti-E2+ve patients were anti-HCV/HCV-RNA+ve and none of our patients were anti-E2+ve/HGV-RNA+ve at the same time. Significant differences were not found between HGV-RNA+ve and HGV-RNA-ve patients as far as clinical and virological data are concerned. CONCLUSIONS: The prevalence of HGV infection in intravenous drug users proved to be high especially in the HIV+ve group. Moreover HGV was associated with HCV in all our cases. The actual clinical impact of HGV infection remains unclear since HGV does not seems to influence the biochemical, virological or histological alterations caused by HCV infection.

Lidocaine elimination and monoethylglycinexylidide formation in patients with chronic hepatitis or cirrhosis.

BACKGROUND/AIMS: The aim of this study was to evaluate the relationship between plasma elimination of lidocaine and monoethylglycinexylidide (MEGX) formation, which is considered to be a quantitative liver function test. METHODOLOGY: The study included ten healthy subjects and 54 patients: 27 with chronic hepatitis and 27 with cirrhosis. Lidocaine and MEGX were measured at 0, 2, 5, 10, 15, 30 min and then every 30 min for 180 min using the TDX system. RESULTS: In cirrhotic patients, the lidocaine half-life of the slow decline phase of the plasma disappearance curve (beta-HL) and the lidocaine half-life of hepatic elimination from the second compartment (K20-HL) proved to be significantly abnormal, as did all parameters of MEGX formation. In chronic hepatitis, both the lidocaine kinetics and the MEGX formation parameters were within the normal range. In chronic hepatitis patients, MEGX formation (AUC 0-180) was significantly correlated to K20-HL (rs = -0.633, p < 0.001) and to the rapid decline phase of the plasma disappearance curve (alpha-HL, rs = -0.483, p < 0.05). In cirrhotic patients, MEGX was significantly correlated to K20-HL (rs = -0.423, p < 0.05) and to beta-HL (rs = -0.500, p < 0.01). CONCLUSIONS: These results show that in chronic active hepatitis, MEGX formation from lidocaine is maintained as a metabolic process, whereas it is altered in cirrhotic patients. The interrelationship between lidocaine elimination and MEGX formation were somewhat different in the two liver diseases.

Chronic hepatitis C. New therapeutic strategies.

BACKGROUND: Aim of this work was to evaluate the early viral decay induced by a daily therapy with alfa-interferon (IFN) and the presence of any synergistic effects of amantadine and ribavirin. METHODS: Twenty patients with a diagnosis of chronic hepatitis C were randomly assigned to receive a course of treatment with: IFN 3MU daily (6 pts); or IFN 3MU daily plus amantadine 200 mg (7 pts): or IFN 3MU daily plus ribavirin 1-1.2 g (7 pts) for 6 months. Blood samples were drown at baseline, at 6, 12, 24, 30 and 48 hrs after the first dose of IFN; at 3, 7, 15 days and at every month. Serum was separated within two hours from the collection and stored at -80 degrees C until use. Viraemia was evaluated qualitatively by the Cobas Amplicor (cut-off 1.00E+02 copies/ml) (Roche Diagnostics, Monza, Milan, Italy) and quantitatively by the Cobas Amplicor Monitor (cut-off 1.00E+03 copies/ml). The HCV genotype was determined for each patient by Inno-LiPA HCV II (Innogenetics, Ghent, Belgium). Liver function tests were evaluated at baseline, at 7 and 15 days and at every month. RESULTS: The analysis of the decay curves showed the presence of a three phase decline in the viraemia. At the end of therapy 7 out of the 20 patients (35%) had normal ALT and undetectable HCV-RNA (2 out of 6 in the IFN group: 33.3%, 3 out of 7: 42.8%; 2 out of 7: 28.6%, in the IFN plus amantadine and IFN plus ribavirin groups respectively). CONCLUSIONS: IFN is the major antiviral effector in the early stage of therapy. The observation of the kinetic curves shows a tendency for the ribavirin to induce a slightly steeper slope of decay in the first 48 hrs, while amantadine seems to induce a slightly deeper abatement of circulating viraemia after 48 hrs.

Study of hardness and roughness modification in explanted joint components.

The significant wear of the UHMWPE bearings of explanted knee prostheses is produced mainly by micrometric debris ("third-body" wear) that diffuse toward the mobile metal-polymer interface. Here debris is crushed during the movement producing scratches in the metal and in the polymeric surfaces. Mechanical stress and the biological effects change the physical polymeric properties. In order to evaluate the area of UHMWE bearings submitted to high load stresses, in this work physical investigations are performed on the explanted knee prosthesis. Particularly, the roughness profile analysis (RPA) and the micro-hardness measurements (MHM) resulted suitable for the localisation of the mechanical and biological wear area. In the stressed zone, surface treatments could be applied in order to improve the mechanical resistance of the polymeric material. Particularly, the ion implantation with heavy ions is proposed to enhance the polymeric wear resistance. The Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectrometry (EDX) and Infrared absorption spectroscopy (FTIR) techniques were also applied and results discussed.