Multidrug resistance in Salmonella isolates of swine origin: mobile genetic elements and plasmids associated with cephalosporin resistance with potential transmission to humans.

The emergence of foodborne Salmonella strains carrying antimicrobial resistance (AMR) in mobile genetic elements (MGE) is a significant public health threat in a One Health context requiring continuous surveillance. Resistance to ciprofloxacin and cephalosporins is of particular concern. Since pigs are a relevant source of foodborne Salmonella for human beings, we studied transmissible AMR genes and MGE in a collection of 83 strains showing 9 different serovars and 15 patterns of multidrug resistant (MDR) previously isolated from pigs raised in the conventional breeding system of Northern Spain. All isolates were susceptible to ciprofloxacin and three isolates carried blaCMY-2 or blaCTX-M-9 genes responsible for cefotaxime resistance. Filter mating experiments showed that the two plasmids carrying blaCTX-M-9 were conjugative while that carrying blaCMY-2 was self-transmissible by transformation. Whole-genome sequencing and comparative analyses were performed on the isolates and plasmids. The IncC plasmid pSB109, carrying blaCMY-2, was similar to one found in S. Reading from cattle, indicating potential horizontal transfer between serovars and animal sources. The IncHI2 plasmids pSH102 in S. Heidelberg and pSTM45 in S. Typhimurium ST34, carrying blaCTX-M-9, shared similar backbones and two novel "complex class 1 integrons" containing different AMR and heavy metal genes. Our findings emphasize the importance of sequencing techniques to identify emerging AMR regions in conjugative and stable plasmids from livestock production. The presence of MGE carrying clinically relevant AMR genes raises public health concerns, requiring monitoring to mitigate the emergence of bacteria carrying AMR genes and subsequent spread through animals and food.IMPORTANCEThe emergence of foodborne Salmonella strains carrying antimicrobial resistance (AMR) in mobile genetic elements (MGE) is a significant public health threat in a One Health context. Since pigs are a relevant source of foodborne Salmonella for humans, in this study, we investigate different aspects of AMR in a collection of 83 Salmonella showing nine different serovars and 15 patterns of multidrug resistant (MDR) isolated from pigs raised in the conventional breeding system. Our findings emphasize the importance of sequencing techniques to identify emerging AMR regions in conjugative and stable plasmids from livestock production. The presence of MGE carrying clinically relevant AMR genes raises public health concerns, requiring monitoring to mitigate the emergence of bacteria carrying AMR genes and subsequent spread through animals and food.

Reduction of subclinical Salmonella infection in fattening pigs after dietary supplementation with a ß-galactomannan oligosaccharide.

AIMS: To assess the efficacy of a ß-galactomannan oligosaccharide (ß-GMOS) for the control of Salmonella infection in fattening pigs. METHODS AND RESULTS: Three different doses (0.5, 3 and 2 kg ß-GMOS per ton of feed) were used during the entire period of growing in three similar and independent field trials carried out in a small fattening unit (≈ 100 pigs). Treatment was randomly assigned to half of the pens. Individual serum samples (20-25 per group) were collected at different times during the fattening period and a similar number of faecal samples during the fattening period and at slaughter. In addition, mesenteric lymph nodes were collected at slaughter. Herdcheck(®) Swine Salmonella ELISA was used for serological analyses, the ISO 6579:2002/Amd 1 : 2007 for bacteriology and the PFGE for molecular characterization of Salmonella strains. The addition of ≥ 2 kg t(-1) of ß-GMOS to the pig diet during the entire fattening period was associated with a reduction in Salmonella prevalence, shedding and seroconversion. CONCLUSIONS: Feed supplementation with ß-GMOS may be a useful complementary tool for the control of salmonellosis in fattening pigs. SIGNIFICANCE AND IMPACT OF THE STUDY: ß-GMOS may be a complementary way of reducing Salmonella shedding and infection in fattening pigs.

Rev1Δwzm vaccine candidate is safe in young and adult sheep and protects against Brucella ovis infection in rams.

Small ruminants affected by brucellosis, caused mainly by Brucella melitensis and B. ovis, suffer reproductive disorders, leading to significant economic losses worldwide. Vaccination is an essential tool to prevent the disease in ovine and caprine livestock, but the only vaccine recommended to date is B. melitensis Rev1, which in sheep is only safe for use in lambs aged 3-4 months. This restriction poses considerable practical challenges for the implementation of Rev1 in countries with endemic brucellosis and/or limited resources, where there is a need for mass vaccination with a safe vaccine to control the disease in both animals and humans. We recently developed a B. melitensis strain Rev1Δwzm showing superior vaccine properties in mice and safety in pregnant ewes. Here, we report that Rev1Δwzm (i) is safe in young and adult sheep, both male and female; (ii) induces a transient serological response in the Rose Bengal test in ≤50 % of sheep, confirmed to some extent by the complement fixation test, and a stronger, more persistent anti- rough-LPS response; and (iii) protects rams against a B. ovis challenge 25 weeks after vaccination. To resolve the problem of serological interference, the use of green fluorescent protein tagging strategy allowed us to identify vaccinated sheep with only a single inoculation. These results, together with the previously reported safety in pregnant ewes, position Rev1Δwzm as a firm vaccine candidate and a promising alternative to Rev1. Further experiments are warranted to assess its efficacy against B. melitensis in pregnant ewes.

Pan-Genome-Wide Association Study reveals a key role of the salmochelin receptor IroN in the biofilm formation of Salmonella Typhimurium and its monophasic variant 4,[5],12:i:.

Salmonella enterica subsp. enterica serovar Typhimurium variant 4,[5],12:i:- (so called S. 4,[5],12:i:-) has rapidly become one of the most prevalent serovars in humans in Europe, with clinical cases associated with foodborne from pork products. The mechanisms, genetic basis and biofilms relevance by which S. 4,[5],12:i:- maintains and spreads its presence in pigs remain unclear. In this study, we examined the genetic basis of biofilm production in 78 strains of S. 4,[5],12:i:- (n = 57) and S. Typhimurium (n = 21), from human gastroenteritis, food products and asymptomatic pigs. The former showed a lower Specific Biofilm Formation index (SBF) and distant phylogenetic clades, suggesting that the ability to form biofilms is not a crucial adaptation for the S. 4,[5],12:i:- emerging success in pigs. However, using a pan-Genome-Wide Association Study (pan-GWAS) we identified genetic determinants of biofilm formation, revealing 167 common orthologous groups and genes associated with the SBF. The analysis of annotated sequences highlighted specific genetic deletions in three chromosomal regions of S. 4,[5],12:i:- correlating with SBF values: i) the complete fimbrial operon stbABCDE widely recognized as the most critical factor involved in Salmonella adherence; ii) the hxlA, hlxB, and pgiA genes, which expression in S. Typhimurium is induced in the tonsils during swine infection, and iii) the entire iroA locus related to the characteristic deletion of the second-phase flagellar genomic region in S. 4,[5],12:i:-. Consequently, we further investigated the role of the iro-genes on biofilm by constructing S. Typhimurium deletion mutants in iroBCDE and iroN. While iroBCDE showed no significant impact, iroN clearly contributed to S. Typhimurium biofilm formation. In conclusion, the pan-GWAS approach allowed us to uncover complex interactions between genetic and phenotypic factors influencing biofilm formation in S. 4,[5],12:i:- and S. Typhimurium.

Sensitivity of the ISO 6579:2002/Amd 1:2007 standard method for detection of Salmonella spp. on mesenteric lymph nodes from slaughter pigs.

The ISO 6579:2002/Amd 1:2007 (ISO) standard has been the bacteriological standard method used in the European Union for the detection of Salmonella spp. in pig mesenteric lymph nodes (MLN), but there are no published estimates of the diagnostic sensitivity (Se) of the method in this matrix. Here, the Se of the ISO (Se(ISO)) was estimated on 675 samples selected from two populations with different Salmonella prevalences (14 farms with a ≥ 20% prevalence and 13 farms with a <20% prevalence) and through the use of latent-class models in concert with Bayesian inference, assuming 100% ISO specificity, and an invA-based PCR as the second diagnostic method. The Se(ISO) was estimated to be close to 87%, while the sensitivity of the PCR reached up to 83.6% and its specificity was 97.4%. Interestingly, the bacteriological reanalysis of 33 potential false-negative (PCR-positive) samples allowed isolation of 19 (57.5%) new Salmonella strains, improving the overall diagnostic accuracy of the bacteriology. Considering the usual limitations of bacteriology regarding Se, these results support the adequacy of the ISO for the detection of Salmonella spp. from MLN and also that of the PCR-based method as an alternative or complementary (screening) test for the diagnosis of pig salmonellosis, particularly considering the cost and time benefits of the molecular procedure.

Identification of early induced genes upon water deficit in potato cell cultures by cDNA-AFLP.

For plant cells in the early phases of water stress exposure, the genes induced under such conditions play a key role in detecting and responding to water deficit. In this study, potato cell suspensions were used as a simplified model system to dissect early molecular changes upon low water potential. In particular, the cDNA-amplified fragment length polymorphism approach was used to capture genes rapidly activated in potato cell cultures in response to water deficit induced by short-term exposure (up to 1 h) to polyethylene glycol. Selective amplifications with 38 primer combinations allowed the visualization of about 167 transcript-derived fragments (TDFs) differentially expressed upon exposure to low water potential. The gene expression pattern of 18 up-regulated genes was further investigated by semi-quantitative reverse transcriptase polymerase chain reaction analysis. Sequencing and similarity analysis revealed that TDFs present homologies chiefly with proteins involved in chaperone activity and protein degradation (hsps, proteinase precursor), in protein synthesis (elongation factor, ribosomal proteins) and in the ROS scavenging pathway (phenylalanine ammonia-lyase, peroxidase). Our findings might contribute to describe the potential role of genes activated in the early phases of plant response to drought.

Vaccine properties of Brucella melitensis 16MΔwzm and reactivation of placental infection in pregnant sheep.

Brucellosis, a worldwide zoonotic disease, is endemic in many developing countries. Besides causing significant economic losses for the livestock industry, it has severe consequences for human health. In endemic regions, small ruminants infected by Brucella melitensis are the main source of human brucellosis. Rev1, the only vaccine currently recommended to control the disease in sheep and goats, has several drawbacks. Rough lipopolysaccharide (R-LPS) mutants have been tested as alternatives, but most lack efficacy. Those in the Wzm/Wzt system responsible for O-polysaccharide export to the periplasm have been proposed as promising vaccine candidates, although to date they have been scarcely investigated in the natural host. In the present work, we studied the biological properties of a 16MΔwzm in-frame deletion mutant, including its safety in pregnant mice and sheep. In mice, 16MΔwzm prevented placental and fetal infections before parturition and protected against B. melitensis and Brucella ovis infections. In sheep, 16MΔwzm was equally safe in lambs, rams, and non-pregnant ewes, inducing some transient Rose Bengal reactions (<7 weeks). The serological reactions occurred earlier and more strongly in pregnant than in non-pregnant ewes and were significantly reduced when conjunctival rather than subcutaneous vaccination was used. In ewes vaccinated at mid-pregnancy, 16MΔwzm was not shed in vaginal discharges during the pregnancy and did not induce abortions/stillbirths. However, some ewes showed a transitory reactivation of infection in placentas and/or milk at parturition, accompanied by a seroconversion in smooth LPS (S-LPS) and/or R-LPS tests. Overall, 16MΔwzm can be considered as a safe vaccine for lambs, rams, and non-pregnant ewes, but its use at mid-pregnancy should be avoided to prevent vaccine dissemination at parturition. If the efficacy results against B. melitensis and B. ovis observed in mice are confirmed by further studies in the natural host, 16MΔwzm could constitute a useful vaccine.

Surgical strategy for the treatment of sporadic medullary thyroid carcinoma: our experience.

BACKGROUND: Medullary thyroid carcinoma (MTC) is a rare disease which accounts for approximately 5-9% of all thyroid cancers and originates from the calcitonin-screening parafollicular C cells. MTC can be divided into two subgroups: sporadic (75%) or inherited (25%). The majority of patients with invasive MTC have metastasis to regional lymph nodes at the time of diagnosis, as evidenced by the frequent finding of persistently elevated calcitonin levels after thyroidectomy and the high rates of recurrence in the cervical lymph nodes reported in retrospective studies. OBJECTIVES: The purpose of the study is to review our single institution's experience with MTC since 1998 and to evaluate surgical strategy, patterns of lymph node metastases and calcitonin response to compartment-oriented lymphadenectomy in patients with primary or recurrent sporadic medullary thyroid carcinoma. METHODS: A retrospective review of 26 patients treated for MTC at the "Antonio Cardarelli" Hospital referral center, in Naples, between 1998 and 2012. There were 18 female and 8 male patients, median age at presentation was 55 years, and median follow-up for survivors was 5 years. Total thyroidectomy was performed in all 26 patients; central compartment (CC) node dissection (level VI) in 12 (46%) patients; central plus lateral compartment (LC) node dissection (levels II, III, and IV) in 7 (27%) patients. 4 patients (15%) underwent reoperation for loco-regional recurrent/persistent MTC. Results. After a median post-surgical follow-up of 5 years (range 1-10 years), 63 % of patients were living disease-free, 15% were living with disease and/or persistently elevated calcitonin levels after surgery, 11% were deceased due to MTC and 11 % were lost to follow-up. CONCLUSIONS: We agree with most authors advocating for a total thyroidectomy and prophylactic central neck dissection in the setting of clinically detected MTC. Lateral neck dissection may be best reserved for patients with positive preoperative imaging. Nevertheless MTC has a high rate of lymph node metastases that are sub optimally detected preoperatively in the central compartment by neck ultrasound or intra-operatively by the surgeon, and reoperation is associated with a higher rate of surgical complications. In our limited experience, patients with thyroid confined nodular pathology, without nodal disease and unknown preoperative diagnosis of MTC, underwent only total thyroidectomy with a good prognosis.

Development of a selective culture medium for primary isolation of the main Brucella species.

Bacteriological diagnosis of brucellosis is performed by culturing animal samples directly on both Farrell medium (FM) and modified Thayer-Martin medium (mTM). However, despite inhibiting most contaminating microorganisms, FM also inhibits the growth of Brucella ovis and some B. melitensis and B. abortus strains. In contrast, mTM is adequate for growth of all Brucella species but only partially inhibitory for contaminants. Moreover, the performance of both culture media for isolating B. suis has never been established properly. We first determined the performance of both media for B. suis isolation, proving that FM significantly inhibits B. suis growth. We also determined the susceptibility of B. suis to the antibiotics contained in both selective media, proving that nalidixic acid and bacitracin are highly inhibitory, thus explaining the reduced performance of FM for B. suis isolation. Based on these results, a new selective medium (CITA) containing vancomycin, colistin, nystatin, nitrofurantoin, and amphotericin B was tested for isolation of the main Brucella species, including B. suis. CITA's performance was evaluated using reference contaminant strains but also field samples taken from brucella-infected animals or animals suspected of infection. CITA inhibited most contaminant microorganisms but allowed the growth of all Brucella species, to levels similar to those for both the control medium without antibiotics and mTM. Moreover, CITA medium was more sensitive than both mTM and FM for isolating all Brucella species from field samples. Altogether, these results demonstrate the adequate performance of CITA medium for the primary isolation of the main Brucella species, including B. suis.

Agmatine transport in brain mitochondria: a different mechanism from that in liver mitochondria.

The diamine agmatine (AGM), exhibiting two positive charges at physiological pH, is transported into rat brain mitochondria (RBM) by an electrophoretic mechanism, requiring high membrane potential values and exhibiting a marked non-ohmic force-flux relationship. The mechanism of this transport apparently resembles that observed in rat liver mitochondria (RLM), but there are several characteristics that strongly suggest the presence of a different transporter of agmatine in RBM. In this type of mitochondria, the extent of initial binding and total accumulation is higher and lower, respectively, than that in liver; saturation kinetics and the flux-voltage relationship also exhibit different trends, whereas idazoxan and putrescine, ineffective in RLM, act as inhibitors. The characteristics of agmatine uptake in RBM lead to the conclusion that its transporter is a channel with two asymmetric energy barriers, showing some characteristics similar to those of the imidazoline receptor I(2) and the sharing with the polyamine transporter.

Assessment of pharmacogenomic SLCO1B1 assay for prediction of neuromuscular pain in type 2 diabetes mellitus and cardiovascular patients: preliminary results.

OBJECTIVE: At present, several strategies for preventing neuromuscular pain in Type 2 Diabetes Mellitus (T2DM) have been investigated. Recently, findings on genetic variants associated with adverse events to statin-based therapy have been reported. The study aimed at measuring whether Pharmacogenomics (PGx) profile can affect neuromuscular pain in patients carrying T2DM and cardiovascular diseases. An extensive panel of 5 polymorphisms on 4 candidate genes, previously validated as significant markers related to Sulphonylureas and Glitinides (SU-G) plus Simvastatin neuromuscular toxicity, is herein analyzed and discussed. PATIENTS AND METHODS: We genotyped 76 T2DM patients carrying cardiovascular dyscrasia undergone anti-diabetic and anti-cholesterolemic polypharmacy. 35 subjects out of the total received concurrent SU-G and Statin-based therapy. Candidate variants consisted of drug transporters, such as Solute Carrier Organic 1B1 (SLCO1B1) Val174Ala ATP-binding cassette subfamily B member (ABCB1), subfamily C member 8 (ABCC8), and drug biotransformers of Cytochrome P450 Family (CYP) including CYP2C9*2 CYP2C9*3 CYP2C8*3, and CYP3A4*22. Moreover, we also focused on an early outline evaluation of the genotyping costs and benefits. RESULTS: 6 out of 35 patients treated with SU-G plus statins (17.1% experienced adverse neuropathy events). Pharmacogenomics analysis showed a lack of any correlation between candidate gene polymorphisms and toxicity, except for the SLCO1B1 T521C allele; 14.3% of patients had a high risk for grade >2 neuromuscular pain (Odds Ratio [OR] 2.61.95% CI 0.90-7.61, p=0.03). CONCLUSIONS: The clinical polymorphism effectiveness outlined therein will be assured by diagnostic improvements suitable for driving treatment decisions. In light of our experimental results and literature data, the analysis of the SLCO1B1 T521C variant will allow clinicians to take advantage from a better treatment planned for their patients in order to minimize neuromuscular pain and maximize benefits.

Cytoplasmic inclusions resembling nucleoli in sympathetic neurons of adult rats.

A distinctive cytoplasmic inclusion consisting of a convoluted network of electron-opaque strands embedded in a less dense matrix was identified in the neurons, but not in the supporting cells, of rat sympathetic ganglia. This ball-like structure, designated "nematosome," measures approximately 0.9 micro and lacks a limiting membrane. Its strands (diameter = 400-600 A) appear to be made of an entanglement of tightly packed filaments and particles approximately 25-50 A thick. Cytochemical studies carried out with the light microscope suggest the presence of nonhistone proteins and some RNA. Usually only one such structure is present in a cell, and it appears to occur in most ganglion cells. Although they can be seen anywhere in the cell body, nematosomes are typically located in the perinuclear cytoplasm, where they are often associated with smooth-surfaced and coated vesicles. In fine structure and stainability, they bear a resemblance to the fibrous component of the nucleolus. Subsynaptic formations, which are a special feature of some of the synapses in sympathetic ganglia, appear similar to the threadlike elements in the nematosomes. The possibility that these three structures-nucleolus, nematosome, and subsynaptic formation-may be interrelated in origin and function is discussed.

Different behavior of agmatine in liver mitochondria: inducer of oxidative stress or scavenger of reactive oxygen species?

Agmatine, at concentrations of 10 microM or 100 microM, is able to induce oxidative stress in rat liver mitochondria (RLM), as evidenced by increased oxygen uptake, H(2)O(2) generation, and oxidation of sulfhydryl groups and glutathione. One proposal for the production of H(2)O(2) and, most probably, other reactive oxygen species (ROS), is that they are the reaction products of agmatine oxidation by an unknown mitochondrial amine oxidase. Alternatively, by interacting with an iron-sulfur center of the respiratory chain, agmatine can produce an imino radical and subsequently the superoxide anion and other ROS. The observed oxidative stress causes a drop in ATP synthesis and amplification of the mitochondrial permeability transition (MPT) induced by Ca(2+). Instead, 1 mM agmatine generates larger amounts of H(2)O(2) than the lower concentrations, but does not affect RLM respiration or redox levels of thiols and glutathione. Indeed, it maintains the normal level of ATP synthesis and prevents Ca(2+)-induced MPT in the presence of phosphate. The self-scavenging effect against ROS production by agmatine at higher concentrations is also proposed.

S-adenosylmethionine and its products.

S-adenosylmethionine is involved in many processes, mainly methylation, polyamine synthesis and radical-based catalysis. It is synthesised through the catalysis of differently regulated enzyme forms. When it is used, the compounds formed are reutilized in different ways: in case of methylation, its end product is homocysteine, which can be remethylated to methionine, give rise to cysteine in the so-called transsulphuration pathway, or be released; in the case of polyamine synthesis, the methylthioadenosine formed is cleaved and gives rise to compounds which can be reutilized; during radical-based catalysis, 5-deoxyadenosine is formed and this, too, is cleaved and reutilized.

Transport of amino acids through the placenta and their role.

Amino acids are transported across the human placenta mediated by transporter proteins that differ in structure, mechanism and substrate specificity. Some of them are Na+-dependent systems, whereas others are Na+-independent. Among these there are transporters composed of a heavy chain, a glycoprotein, and a light chain. Moreover, they can be differently distributed in the two membranes forming the syncytiotrophoblast. The transport mechanisms involved and their regulation are only partially known. In the placenta itself, part of the amino acids is metabolized to form other compounds important for the fetus. This occurs for instance for arginine, which gives rise to polyamines and to NO. Interconversion occurs among few other amino acids Transport is altered in pregnancy complications, such as restricted fetal growth.

Advanced glycation end-products (AGEs): involvement in aging and in neurodegenerative diseases.

Advanced glycation end-products (AGEs) are formed from the so-called Amadori products by rearrangement followed by other reactions giving rise to compounds bound irreversibly. The structure of some of them is shown and the mechanism of formation is described. Several AGE binding molecules (Receptors for AGE, RAGE) are known and it is thought that many of the effects caused by AGEs are mediated by RAGE. Some of these were shown to be toxic, and called TAGE. The mechanism of detoxification of glyoxal and methylglyoxal by the glyoxalase system is described and also the possibility to eliminate glycated proteins by deglycation enzymes. Compounds able to inhibit AGEs formation are also taken into consideration.

Serum prolactin levels in HLA-B27-associated uveitis.

PURPOSE: To evaluate basal serum prolactin levels in patients with HLA-B27-associated uveitis. METHODS: Prospective, nonrandomized comparative trial. Thirty-three patients with HLAB27- associated uveitis and 30 age- and sex-matched healthy control subjects were included. Age, systemic disease, treatment, and uveitis activity were recorded for comparative analysis between groups. Fourteen out of 23 patients with arthritic disease had ankylosing spondylitis. Basal serum prolactin levels were determined by electrochemiluminescence immunoassay on a Modular Analytics E170 analyzer. RESULTS: Prolactinemia was significantly higher (mean=15.84 ng/mL) in patients vs controls (mean=11.50 ng/mL) (p=0.026). Subgroup analysis revealed prolactinemia in arthritic disease patients (mean=17.21 ng/mL) significantly higher than controls (mean=11.50 ng/mL) (p=0.009) and in ankylosing spondylitis (mean=17.65 ng/mL) vs controls (mean=11.50 ng/mL) (p=0.006). No correlation was found between prolactinemia and systemic treatment. Prolactinemia did not correlate with disease activity. Autoimmunity features also correlated with higher prolactinemia (mean=17.26 ng/mL) vs controls (mean=11.50 ng/mL) (p=0.015). CONCLUSIONS: These results suggest the role of serum prolactin levels in HLA-B27-associated uveitis pathogenesis and its subgroups. There was no correlation with disease activity.

Relationship between Salmonella infection, shedding and serology in fattening pigs in low-moderate prevalence areas.

Salmonella is a major foodborne pathogen causing important zoonosis worldwide. Pigs asymptomatically infected in mesenteric lymph nodes (MLN) can be intermittent shedders of the pathogen through faeces, being considered a major source of human infections. European baseline studies of fattening pig salmonellosis are based on Salmonella detection in MLN. This work studies the relationship between Salmonella infection in MLN and intestinal content (IC) shedding at slaughter and the relationship between the presence of the pathogen and the serologic status at farm level. Mean Salmonella prevalence in the selected pigs (vertically integrated production system of Navarra, Spain) was 7.2% in MLN, 8.4% in IC and 9.6% in serum samples. In this low-moderate prevalence context, poor concordance was found between MLN infection and shedding at slaughter and between bacteriology and serology. In fact, most of shedders were found uninfected in MLN (83%) or carrying different Salmonella strains in MLN and in IC (90%). The most prevalent Salmonellae were Typhimurium resistant to ACSSuT ± Nx or ASSuT antibiotic families, more frequently found invading the MLN (70%) than in IC (33.9%). Multivariable analysis revealed that risk factors associated with the presence of Salmonella in MLN or in IC were different, mainly related either to good hygiene practices or to water and feed control, respectively. Overall, in this prevalence context, detection of Salmonella in MLN is an unreliable predictor of faecal shedding at abattoir, indicating that subclinical infections in fattening pigs MLN could have limited relevance in the IC shedding.

Diagnostic value of arterial blood gas lactate concentration in the different forms of mesenteric ischemia.

PURPOSE: The role of serum lactate measurement in patients with intestinal ischemia still remains unclear. The aim of this study was to prospectively evaluate the diagnostic performance of arterial blood gas lactate concentrations in the patients with acute mesenteric ischemia and its different forms. METHODS: All the patients reporting abdominal pain associated with risk factors for mesenteric ischemia underwent arterial blood gas and contrast enhanced abdominal computer tomography (CT). RESULTS: At CT, 201 patients (70.7%) showed a nonischemic disease (group 1) and 83 patients (29.2%) showed findings of mesenteric ischemia. Out of these, 35 patients (42.1%) showed bowel ischemia secondary to non vascular causes (group 2) and 48 (57.8%) had a vascular intestinal ischemia (group 3). Out of these, 20 showed small bowel arterial occlusion (group 3a), 13 a small bowel nonocclusive ischemia (group 3b), 7 a venous small bowel occlusion (group 3c) and 8 showed isolated colonic ischemia (group 3d). The median lactate serum level was significantly higher in patients with vascular ischemia if compared with patients with nonischemic disease and secondary mesenteric ischemia (p < 0.0001; Kruskal-Wallis test). The areas under ROC curves for the lactate serum levels in the groups 2, 3, 3a, 3b, 3c and 3d were, respectively, 0.61, 0.85, 0.93, 0.93, 0.68 and 0.67. CONCLUSIONS: Arterial blood gas lactate levels seem to show good diagnostic accuracy in diagnosing small bowel arterial and nonocclusive ischemia and poor accuracy in diagnosing secondary mesenteric ischemia, small bowel venous ischemia and ischemic colitis.

Olf-1-binding site: characterization of an olfactory neuron-specific promoter motif.

We report characterization of several domains within the 5' flanking region of the olfactory marker protein (OMP) gene that may participate in regulating transcription of this and other olfactory neuron-specific genes. Analysis by electrophoretic mobility shift assay and DNase I footprinting identifies two regions that contain a novel sequence motif. Interactions between this motif and nuclear proteins were detected only with nuclear protein extracts derived from olfactory neuroepithelium, and this activity is more abundant in olfactory epithelium enriched in immature neurons. We have designated a factor(s) involved in this binding as Olf-1. The Olf-1-binding motif consensus sequence was defined as TCCCC(A/T)NGGAG. Studies with transgenic mice indicate that a 0.3-kb fragment of the OMP gene containing one Olf-1 motif is sufficient for olfactory tissue-specific expression of the reporter gene. Some of the other identified sequence motifs also interact specifically with olfactory nuclear protein extracts. We propose that Olf-1 is a novel, olfactory neuron-specific trans-acting factor involved in the cell-specific expression of OMP.