Healthy Farm Research Articles

Molecular characterization of cytolethal distending toxin gene-positive Escherichia coli from healthy cattle and swine in Nara, Japan.

BackgroundCytolethal distending toxin (CDT)-producing Escherichia coli (CTEC) has been isolated from patients with gastrointestinal or urinary tract infection, and sepsis. However, the source of human infection remains unknown. In this study, we attempted to detect and isolate CTEC strains from fecal specimens of healthy farm animals and characterized them phenotypically and genotypically.ResultsBy PCR analysis, the cdtB gene was detected in 90 and 14 out of 102 and 45 stool specimens of healthy cattle and swine, respectively, and none from 45 chicken samples. Subtypes of the cdtB genes (I to V) were further examined by restriction fragment length polymorphism analysis of the amplicons and by type-specific PCRs for the cdt-III and cdt-V genes. Of the 90 cdtB gene-positive cattle samples, 2 cdt-I, 25 cdt-III, 1 cdt-IV, 52 cdt-V and 1 both cdt-III and cdt-V gene-positive strains were isolated while 1 cdt-II and 6 cdt-V gene-positive were isolated from 14 cdtB positive swine samples. Serotypes of some isolates were identical to those of human isolates. Interestingly, a cdt-II gene-positive strain isolated from swine was for the first time identified as Escherichia albertii. Phylogenetic analysis grouped 87 E. coli strains into 77 phylogroup B1, 6 B2, and 4 D, respectively. Most of the B1 strains harbored both lpfA O113 and ehaA. Three and twenty-two cdt-V gene-positive strains harbored eaeA and stx genes, respectively, and seven possessed cdt-V, stx and subAB genes. The cnf2 gene, normally present in cdt-III gene-positive strains, was also detected in cdt-V gene-positive strains.ConclusionsOur results suggest that healthy cattle and swine could be the reservoir of CTEC, and they could be a potential source of human infections.

Subtype analysis of Salmonella isolated from subclinically infected dairy cattle and dairy farm environments reveals the presence of both human- and bovine-associated subtypes

While it is well established that clinically ill livestock represent a reservoir of Salmonella, the importance of subclinical shedders as sources of human salmonellosis is less well defined. The aims of this study were to assess the subtype diversity of Salmonella in healthy dairy cattle and farm environments and to compare the subtypes isolated from these sources with the Salmonella subtypes associated with clinical human cases in the same geographic area. A total of 1349 Salmonella isolates from subclinical dairy cattle and farm environments (46 farms) were initially characterized by traditional or molecular serotyping and tested for antimicrobial susceptibility. A set of 381 representative isolates was selected for further characterization by pulsed-field gel electrophoresis (PFGE); these isolates represented unique combinations of sampling date, serovar, antimicrobial resistance pattern, farm of origin, and source, to avoid overrepresentation of subtypes that were re-isolated from a given source. These 381 isolates represented 26 Salmonella serovars; the most common serovars were Cerro [(38.8%, 148/381) isolated from 21 farms], Kentucky [16.3%; 10 farms], Typhimurium [9.4%; 7 farms], Newport [7.6%; 8 farms], and Anatum [6.3%; 6 farms]. Among the 381 isolates, 90 (23.6%) were resistant to between 1 and 11 antimicrobial agents, representing 50 different antimicrobial resistance patterns. Overall, 61 XbaI-PFGE types were detected among these 381 isolates, indicating considerable Salmonella diversity on dairy farms. Fourteen PFGE types, representing 12 serovars, exactly matched PFGE types from human isolates, suggesting that subclinically infected dairy cattle could be sources of human disease-associated Salmonella.

A 31 Year-Old Brazilian Man with Exanthematous Lesions

A 31 year-old man, previously healthy Brazilian farm worker presented to the local public health clinic with a five day history of flulike symptoms, such as headache, malaise and myalgia, and with cutaneous lesions distributed on both hands and forearms. The patient also reported high fever and axillary lymphadenopathy on his right side. Peripheral erythema was also observed on the same arm. The lesions were in multiple stages of development ranging from papules to blister-like vesicles, pustules and ulcers. Some lesions had a purulent secretion. The patient reported direct contact with dairy cows (handling and milking), that were presenting with the same kind of ulcerative lesions. The patient received analgesics for the pain and fever and also antibiotics for topical use on the pustular lesions. Although he was not hospitalized, he was unable to work for 5-6 days, when papules and vesicular lesions turned pustules and ulcers. Around 8 days later he returned to the clinic and the pustules and ulcers had started to heal developing into black scars. The patient reported he was feeling better and was able to return to work. What is your diagnosis?

MOLECULAR CHARACTERIZATION AND IMMUNOPROTECTIVE ACTIVITY OF CAPSULAR POLYSACCHARIDE OF <I>KLEBSIELLA PNEUMONIAE</I> ISOLATED FROM FARM ANIMALS AT TAIF GOVERNORATE

Klebsiella pneumoniae is a Gram-negative enterobacterium that has histor ically been and currently remains, a significant cause of human disease and several kind s of infections in animals. In the present work, tr ials for the isolation of Klebsiella pneumoniae from diseased and apparently healthy farm animals (cows, sheep, goats and camels) were done for recognition of Klebsiella pneumoniae subspecies. It was noticed that there was a marked variation between incidences of Klebsiella pneumoniae subspecies in examined animals as regards to healt h condition. The frequency was greater among samples collected from diseased animals 25.2% as compared with apparently healthy one 5.5%. It was found that ther e was great difference between the prevalence of Klebsiella isolated from various animal origins. On biochemica l identification Klebsiella pneumoniae subsp. pneumoniae was the most prevalent followed by Klebsiella pneumoniae subsp. ozaenae and Klebsiella pneumoniae subsp. Rhinoscleromatis. Klebsiella pneumoniae subsp. rhinoscleromatis was not isolated from appa rently healthy animals. The in vitro sensitivity of isolates of Klebsiella pneumoniae subspecies recovered from different animal species to 23 antimicrobial agents was tested. It w as found that were resistance to cefoxitin, cefotax ime, cefoperazone, ceftazidime, ceftriaxone, aztreonam, amoxicillin and ampicillin. The most potent antibio tics showing 100% activity against Klebsiella pneumoniae subsp. isolated in this study were imipenem, cipro floxacin, norfloxacin, gentamicin and kanamycin. While 96.2% of all examined isolates were sensitive to amoxicillin/clavulanic acid and ticarcillin/clavula nic acid. SDS-PAGE analysis showed that CPSs of Klebsiella pneumoniae subspecies contained wide variety of different mol ecular weights which ranged from 15.52 kDa to106.29 kDa and gave 10-13 bands. Evaluation of humoral immune response of mice immunized with CPSs was done using ELISA. It was found that the highest immune response was obtained 14 days post 1st dose of immunization with extracted CPSs of the three Klebsiella pneumoniae subspecies. When mice were immunized with CPSs of Klebsiella pneumoniae subspecies, they were protected against virulent c hallenge with homologous or heterologous strains, as a result the mortality rates were reduced from 80, 75 and 65 to 5 to 15% o f Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae and Klebsiella pneumoniae subsp. rhinoscleromatis, respectively. Determination of th e reisolation rates of Klebsiella pneumoniae subspecies from lung, liver and spleen were done on both immunized mice and challenged and on control mice. Histopathological studies have been done on both dead infected non-immunized and immunized mice. Lungs were the main organs that showed macroscopic and microscopic pathological changes. Finally, ELISA has been used for detecti on of CPSs of Klebsiella pneumoniae subspecies antibodies in sera of examined animals. The sensitivity of ELISA using CPSs extracted from Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae and Klebsiella pneumoniae subsp. rhinoscleromatis was 87.7, 89.0 and 83.6%, respectively. The specificity of this ELISA was 93.4, 92.9 and 93.1%, respectively. ELISA using CPSs antigens could therefore serve as a valuable aid in serodiagnosis of Klebsiella pneumonia.

Species diversity and antibiotic resistance properties of Staphylococcus of farm animal origin in Nkonkobe Municipality, South Africa.

The occurrence and antibiotic susceptibility profile of Staphylococcus isolates of healthy farm animal origin in Nkonkobe Municipality as well as the prevalence of putative antibiotic resistance genes were investigated using phenotypic and molecular methods. A total of 120 Staphylococcus isolates were isolated from 150 animal samples and consisted of Staphylococcus haemolyticus (30 %) and Staphylococcus aureus (23.3 %) from pig, Staphylococcus capitis (15 %) from goat, S. haemolyticus (5 %) and Staphylococcus xylosus (15 %) from cattle, and other staphylococci (11.7 %) from dead chicken and pigs. Besides this, the presence of these isolates was observed from the animal dung, showing that the organisms are shed to the environment. About 23.3 % of these isolates were coagulase-positive and 76.7 % were coagulase-negative Staphylococcus. Between 75 and 100 % of the isolates were resistant to penicillin G, tetracycline, sulfamethoxazole, and nalidixic acid; about 38 % were methicillin-resistant staphylococci, including 12.6 % methicillin-resistant S. aureus from pigs. In total, 12 % of all isolates were vancomycin resistant. Also, 12 % of the isolates were erythromycin resistant, while 40.2 % were resistant to ceftazidime. Only the genes mecA and mphC could be confirmed, whereas the genes vanA, vanB, ermA, ermB, and ermC could not be detected. The high phenotypic antibiotic resistance and the presence of some associated resistance genes is a potential threat to public health and suggest the animals to be important reservoirs of antibiotic resistance determinants in the environment.

US-guided application of Nd:YAG laser in porcine pancreatic tissue: an ex vivo study and numerical simulation

Laser ablation (LA) with a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is a minimally invasive approach able to achieve a high rate of complete tissue necrosis. In a previous study we described the feasibility of EUS-guided Nd:YAG pancreas LA performed in vivo in a porcine model. To establish the best laser setting of Nd:YAG lasers for pancreatic tissue ablation. A secondary aim was to investigate the prediction capability of a mathematical model on ablation volume. Ex vivo animal study. Hospital animal laboratory. Explanted pancreatic glands from 60 healthy farm pigs. Laser output powers (OP) of 1.5, 3, 6, 10, 15, and 20 W were supplied. Ten trials for each OP were performed under US guidance on ex vivo healthy porcine pancreatic tissue. Ablation volume (Va) and central carbonization volume (Vc) were measured on histologic specimens as the sum of the lesion areas multiplied by the thickness of each slide. The theoretical model of the laser-tissue interaction was based on the Pennes equation. A circumscribed ablation zone was observed in all histologic specimens. Va values grow with the increase of the OP up to 10 W and reach a plateau between 10 and 20 W. The trend of Vc values rises constantly until 20 W. The theoretical model shows a good agreement with experimental Va and Vc for OP between 1.5 and 10 W. Ex vivo study. Volumes recorded suggest that the best laser OP could be the lowest one to obtain similar Va with smaller Vc in order to avoid the risk of thermal injury to the surrounding tissue. The good agreement between the two models demonstrates the prediction capability of the theoretical model on laser-induced ablation volume in an ex vivo animal model and supports its potential use for estimating the ablation size at different laser OPs.

Shot in the foot

A 24-year-old previously healthy farm worker was out shooting rabbits in the field when he accidentally dropped his gun. The gun fired, shooting him in the left foot. He presented...

A farm-scale biodiversity and ecosystem services assessment tool: the healthy farm index

Farm management focused on maximizing biomass production results in biological simplification and ultimately a degraded production potential for the future. Despite the large and growing body of evidence pointing to the need to restore biodiversity to farm systems, incorporation of biodiversity and ecosystem services into local agricultural land-use decision-making remains limited. The lack of planned and associated biodiversity may reduce resiliency of local managed ecosystems and add management costs; however, the tradeoff for individual landowners of greater diversity is increased management complexity and uncertainty. To assist farmers in managing biodiversity and to encourage ecological thinking, we developed the Healthy Farm Index, a farm-scale tool that complements existing farm assessment tools by integrating multiple metrics and outputs suitable for applied decision-making and annual evaluation. In this article, we describe the impetus for the index development and the structure of the index and through a case study apply the index and discuss its varied outputs and applications.

Sa1542 Evolving Role of Endoscopic Ultrasound Before Surgery After Medical Down-Staging of Pancreaticobiliary Cancers

has been already applied as a minimally invasive, palliative therapy in hepatic and thyroid lesions. In a previous study we assessed the feasibility of EUS Nd: YAG LA on normal pancreatic tissue performed in-vivo in a porcine model. Aims: to confirm the feasibility and to evaluate the safety and the efficacy of EUS Nd:YAG LA on normal pancreatic tissue of in-vivo porcine model. Material and Methods: Six healthy farm swines, weighted 40-50 Kg, underwent pancreas LA under EUS control during general anaesthesia. Pancreatic gland was punctured with a 19-gauge needle through transgastric approach. A 1.064-nm wavelenght Nd:YAG laser was used. Output power of 2 and 3 W with a total delivered energy of 1000 J was supplied in continuous mode, as used in our previous pilot study. Serum levels of amylase, lipase and transaminase were obtained at baseline, after three hours of the endoscopic treatment, and before the euthanizing of the animals. After the endoscopic treatment the animals were observed for clinical signs of pancreatitis (loss of appetite, altered consciousness and irritability). After 1 month the animals were sedated and then euthanized by i.v. injection of pento-barbital (100mg/Kg). The EUS-LA target organ was excised and placed in formalin. Histological examination of the specimens was performed by a single pathologist. Results: All pancreatic specimens showed histological signs of coagulative necrosis. The ablation volume ranged from a mean of 357 to 590 mm3. No histochemical signs of pancreatitis were found at pathologic examination. All the pigs survived at 1 month. During the follow-up no pigs showed clinical signs of pancreatitis and biochemical parameters were normal. No other complications were detected at necropsy. Conclusions: EUSguided Nd:YAG LA of pancreas performed in vivo in a porcine model is feasible and safe. Nd:YAG laser creates a time-dependent ablation volume. Furthermore other studies are needed to apply this mini-invasive approach to human pancreatic lesions.

OC.04.2 DIAGNOSTIC ACCURACY OF RECTAL ENDOSCOPIC ULTRASONOGRAPHY TO DIAGNOSE DEEP PELVIC ENDOMETRIOSIS: EXPERIENCE FROM TWO REFERRAL GASTROENTEROLOGY UNITS

Background and aim: Intraoperatory radiofrequency ablation (RFA) of pancreas cancer has <8% complication rate.The ultrasound (EUS)-guided laser ablation might reduce risk because it is less invasive and able to discriminate the intervening vessels. Laser ablation (LA) performed with a neodymium:yttrium-aluminum garnet (Nd:YAG) laser can achieve a high rate of complete tissue necrosis and has been applied as a minimally invasive, palliative therapy in hepatic and thyroid lesions. In a previous study we assessed the feasibility of EUS Nd:YAG LA on normal pancreatic tissue performed in-vivo in a porcine model. Aims is to confirm the feasibility and to evaluate the safety and the efficacy of EUS Nd:YAG LA on normal pancreatic tissue of in-vivo porcine model. Material and methods: Six healthy farm swines, weighted 40-50 kg, underwent pancreas LA under EUS control during general anaesthesia. Pancreatic gland was punctured with a 19-gauge needle through transgastric approach. A 1.064-nm wavelenght Nd:YAG laser was used. Output power of 2 and 3 W with a total delivered energy of 1000 J was supplied in continuous mode, as used in our previous pilot study. Serum levels of amylase, lipase and transaminase were obtained at baseline, after three hours of the endoscopic treatment, and before the euthanizing of the animals. After the endoscopic treatment the animals were observed for clinical signs of pancreatitis (loss of appetite, altered consciousness and irritability). After 1 month the animals were sedated and then euthanized. The EUS-LA target organ was excised and placed in formalin. Histological examination of the specimens was performed by a single pathologist. Results: All pancreatic specimens showed histological signs of coagulative necrosis. The ablation volume ranged from a mean of 357 to 590 mm3. No histochemical signs of pancreatitis were found at pathologic examination. All the pigs survived at 1 month. During the follow-up no pigs showed clinical signs of pancreatitis and biochemical parameters were normal. No other complications were detected at necropsy. Conclusions: EUS-guided Nd:YAG LA of pancreas performed in vivo in a porcine model is feasible and safe. Nd:YAG laser creates a time-dependent ablation volume. Furthermore other studies are needed to apply this mini-invasive approach to human pancreatic lesions. OC.04.2

Emergence of -lactamases OXA-10, VEB-1 and CMY in Providencia spp. from Nigeria

Emergence of -lactamases OXA-10, VEB-1 and CMY in Providencia spp. from Nigeria

Diagnostic Utility of Egg Yolk for the Detection of Avian Metapneumovirus Antibodies in Laying Hens

Surveillance and diagnosis of avian metapneumovirus (AMPV) infection typically involve measurement of serum antibodies. In the current study, eggs instead of serum samples were used for the detection of AMPV antibodies in egg-laying chicken hens by enzyme-linked immunosorbent assay (ELISA). AMPV-free commercial layer hens were experimentally challenged with AMPV strain SC1509 through intravenous or oculonasal administration. Antibody levels were determined by ELISA. AMPV antibodies were detected in egg yolks from challenged hens by 7 days postinoculation (dpi), with the peak titer at 16 dpi. Antibody levels in eggs laid at 28 dpi correlated well (r = 0.93) with sera taken 28 dpi from the same hens. In a field trial of the yolk ELISA, six broiler breeder farms were surveyed, and all tested positive for AMPV antibodies in hen eggs, although positivity varied from farm to farm. Abnormal discolored eggs collected from outbreak farms had significantly higher titers of AMPV yolk antibodies than normal eggs from the same farm, unlike clinically healthy farms, where normal and abnormal eggs had similar antibody titers. These results indicate that diagnosis of AMPV infection by yolk ELISA to detect anti-AMPV antibodies may be a suitable alternative to serologic testing.

Transferable Class 1 and 2 Integrons inEscherichia coliandSalmonella entericaIsolates of Human and Animal Origin in Lithuania

Antibiotic-resistant Escherichia coli (n = 191) and Salmonella enterica (n = 87) isolates of human and animal origin obtained in Lithuania during 2005-2008 were characterized for the presence and diversity of class 1 and 2 integrons. E. coli isolates were obtained from patients with urinary tract infections (UTIs) (n = 59) and both healthy and diseased farm animals, including poultry (n = 54), swine (n = 35), and cattle (n = 43). Isolates of non-typhoidal S. enterica were recovered from salmonellosis patients (n = 37) and healthy animals, including poultry (n = 31) and swine (n = 19). The presence of integrons, their gene cassette structure, and genome location were investigated by polymerase chain reaction, restriction fragment-length polymorphism, DNA sequencing, Southern blot hybridization, and conjugation experiments. Forty percent of the E. coli and 11% of the S. enterica isolates carried class 1 integrons, whereas class 2 integrons were found in E. coli isolates (9%) only. The incidence of integrons in human UTIs and cattle isolates was most frequent (p < 0.01). A total of 23 different gene cassettes within 15 different variable regions were observed. Seven different integron types, all of them transferable by conjugation, were common for isolates from human infections and for one or more groups of animal isolates. The most prevalent integron types contained arrays dfrA1-aadA1 (36%), dfrA17-aadA5 (23%), and dfrA1-sat1-aadA1 (78%). Two E. coli isolates from humans with UTIs harbored class 1 integron on conjugative plasmid with the novel array type of 4800 bp/dfrA17-aadA5Δ-IS26-ΔintI1-aadB-aadA1-cmlA residing on the Tn21-like transposon. Three S. enterica isolates from swine contained class 1 integron with the newly observed array type of 1800 bp/aadA7-aadA7. Integrons of 10 different types of both classes were located on transferable plasmids in E. coli and S. enterica. Our study demonstrated the existence of a considerable and common pool of transferable integrons in E. coli and S. enterica present in clinical and livestock environment in Lithuania.

Effect of Particle Size on Respiratory Protection Provided by Two Types of N95 Respirators Used in Agricultural Settings

This study compared size-selective workplace protection factors (WPFs) of an N95 elastomeric respirator (ER) and an N95 filtering facepiece respirator (FFR) in agricultural environments. Twenty-five healthy farm workers ranging in age from 20 to 30 years voluntarily participated in this study. Altogether, eight farms were included representing three different types: two horse farms, three pig barns, and three grain handling sites. Subjects wore the ER and FFR while performing their daily activities, such as spreading hay, feeding livestock, and shoveling. Aerosol concentrations in an optical particle size range of 0.7–10 μm were determined simultaneously inside and outside the respirator during the first and last 15 min of a 60-min experiment. For every subject, size-selective WPFs were calculated in 1-min intervals and averaged over 30 min. For the ER, geometric mean WPFs were 172, 321, 1013, 2097, and 2784 for particle diameters of 0.7–1.0, 1.0–2.0, 2.0–3.0, 3.0–5.0, and 5.0–10.0 μm, respectively. Corresponding values for the FFR were 67, 124, 312, 909, and 2089. The 5th percentiles for the ER and FFR were higher than the assigned protection factor of 10 and varied from 28 to 250 and from 16 to 223, respectively. Results show that the N95 ER and FFR tested in the study provided an expected level of protection for workers on agricultural farms against particles ranging from 0.7 to 10 μm. WPFs for the ER were higher than the FFR for all particle size ranges. WPFs for both respirator types increased with increasing particle size.

A new, very sensitive method of assessment of ptaquiloside, the major bracken carcinogen in the milk of farm animals

We describe a new method to detect trace levels of ptaquiloside (Pta), a major carcinogen of bracken fern in biological samples such as milk from farm animals. The method involves the absorption of analyte on carbograph followed by elution with solvents mixtures. The unstable analyte is then converted into Br-Pt (II), which is specific for Pta, as it is not a natural decay product of the glycoside in aqueous media. An internal standard, the Br-pterosine-d 2, prepared in our laboratories has been used. Detection and quantification are possible with gas chromatography/mass spectrometry (GC/MS) in single ion monitoring mode (SIM). The detectable amount is in the range of ppb. The method allowed us to detect Pta not only in the milk from bracken fern-poisoned cattle but also, for the first time, in the milk from healthy farm animals such as sheep, goat, horse, and donkey mares.

Gastric lymphatic basin dissection for sentinel node biopsy using hybrid natural orifice transluminal endoscopic surgery (NOTES)

The aim of the present study was to describe a method of gastric lymphatic basin dissection for sentinel node biopsy using natural orifice transluminal endoscopic surgery with laparoscopic assistance (hybrid NOTES) in a porcine model. Lymph node dissection was performed in three healthy female domestic farm pigs (each around 40 kg) between October, 2007, and December, 2007. The pigs were administered a general anesthetic and laparoscopy-guided transvaginal colpotomy was performed. A two-channel endoscope was then inserted through the incision into the peritoneal cavity via the transvaginal route. An endoscope was inserted simultaneously into the mouth and indocyanine green solution was injected into the submucosal layer of the gastric wall at four sites. Dyed omentum and lymphatics were dissected using a laparoscopic dissector and the grasping forceps of a transvaginal endoscope. Lymphatics and omentum (mean 13.3 cm, range 8–20 cm) were removed transvaginally. The mean number of detected and resected sentinel nodes was 2.6 (range 1–4, diameter 2∼12 mm). Sentinel lymphatic basin dissection was performed successfully and without intraoperative complications in all three cases. Hybrid NOTES is technically feasible, and this procedure may represent an alternative to laparoscopic sentinel lymph node dissection of the stomach.

Concentration of β-ecydisone (20E) in susceptible and resistant accessions of Pfaffia glomerata infected with Meloidogyne incognita and histological characterisation of resistance

Abstract Pfaffia glomerata is a medicinal plant widely distributed in Brazil, which is considered the world's greatest supplier of P. glomerata roots. Among active ingredients contained in this plant, the steroid β-ecydisone (20E) is the most important compound extracted from roots. This steroid presents therapeutic properties for the treatment of diabetes and haemorrhoids, besides having bioenergy, tonic and aphrodisiac effects. The root-knot nematode Meloidogyne spp. is a major limiting factor in root production. Recent studies showed resistance of accessions of P. glomerata to Meloidogyne incognita. The aims of this work were: i) to correlate the concentration of 20E with resistance and susceptibility of P. glomerata accessions to M. incognita in inoculated and non-inoculated plants; ii) to study the effect of the parasitism of M. incognita on the concentration of the steroid 20E in the roots; and iii) to clarify resistance mechanisms by comparing the response of a highly resistant UFV with a highly susceptible accession (Farm) to nematode infection. The concentration of 20E in the healthy susceptible Farm accession was significantly higher than in the healthy resistant UFV accession, showing that the resistance mechanism was not related to 20E concentrations. Plants of the Farm accession infected with M. incognita showed higher levels of 20E than the non-infected control. A positive and significant Pearson correlation coefficient was observed between 20E concentrations and gall indexes. Resistance of UFV to the root-knot nematode M. incognita was associated with unidentified factors that limited nematode penetration or emigration of second-stage juveniles and with post-penetration responses, including the hypersensitive response. Giant cells were sometimes found in the resistant cultivar, but displayed a highly vacuolated and degraded cytoplasm with thinner cell walls than those induced in the susceptible accession. Microscope observations under UV light showed a strong autofluorescence, suggesting that phenolic compounds may be involved in ginseng UFV resistance.

Arcobacter in a food safety perspective

Arcobacters are increasingly Isolated from food products and have been classified as emerging food pathogens In the past, they were predominantly associated with reproductive problems, mastitis and gastric ulcers in livestock, though recently they are frequently isolated from clinically healthy farm animals. In humans, Arcobacter is associated with enteritis with in some cases septicaemia. The routes of infection are Still unclear but included, person-to-person contact and consumption of contaminated water and food. At present, there is no unequivocal evidence that arcobacters are hazards for human health, but neither are they part of the normal commensal flora. The current status Of the pathogen and the importance of food contamination is reviewed.

Post-Weaning Multisystemic Wasting Syndrome and Other PCV2-Related Problems in Pigs: a 12-Year Experience

Post-weaning multisystemic wasting syndrome (PMWS) and other porcine circovirus type 2 (PCV2)-related diseases have been reported throughout the world for about 10 years. The present paper reviews the knowledge acquired in different fields and is largely based on the authors' experience. The horizontal transmission of PCV2 is widely documented. Contact between pigs is the main route of transmission for both PCV2 and PMWS. However, experimental inoculation of PCV2 to pigs does not give consistent results and severe clinical signs as encountered in the field are rarely obtained. It is thus acknowledged that additional conditions are required for the disease to be severe in growing pigs. These are not all known but co-infections are thought to act as triggers. The spread of such triggers/enhancers, which may or may not be infectious, could have played a role in PMWS dissemination via normal national and international trade, in some cases conferring an epidemic pattern to this spread. Most of the risk factors identified in surveys relate to poor biosecurity and inadequate hygiene/husbandry/herd management. The good correlation between viral burden in the tissues and disease severity emphasized the role of infection pressure. Genomic analysis showed great similarities between PCV2 isolates. However, although two main genotypes (genogroups) could be distinguished from the phylogenic trees, and changes with time, no clear relationship with strain virulence was apparent. Isolates detected in PMWS-positive pigs could also be detected in healthy pigs from healthy farms. A strong sow effect was observed in disease expression in the offspring. Colostrum composition and colostrum intake are supposed to be key components of disease expression. Medication is relatively inefficient as a control measure. Commercial PCV2 vaccines are now becoming available. However, losses as a result of PMWS and PCV2-related diseases are greatly reduced by applying appropriate hygiene and husbandry practices.

Phylogenetic analysis of porcine circovirus type 2 (PCV2) pre- and post-epizootic postweaning multisystemic wasting syndrome (PMWS)

The porcine circovirus type 2 (PCV2) genome encodes three major open reading frames (ORFs) encoding the replicase proteins (ORF1), the viral capsid protein (ORF2), and a protein with suggested apoptotic activity (ORF3). Previous phylogenetic analyses of complete genome sequences of PCV2 from GenBank have demonstrated 95-100% intra-group nucleotide sequence identity. However, although these isolates were readily grouped into clusters and clades, there was no correlation between the occurrence of specific PCV2 genotypes and the geographic origin or health status of the pig. In the present study, a unique dataset from a field study spanning the years pre and post the recognition of postweaning multisystemic wasting syndrome (PMWS) in Sweden was utilized. Using this dataset it was possible to discriminate three Swedish genogroups (SG1-3) of PCV2, of which SG1 was recovered from a pig on a healthy farm ten years before the first diagnosis of PMWS in Sweden. The SG1 PCV2/ORF2 gene sequence has been demonstrated to exhibit a high genetic stability over time and has subsequently only been demonstrated in samples from pigs on nondiseased farms. In contrast, SG2 was almost exclusively found on farms that had only recently broken down with PMWS whereas the SG3 genogroup predominated in pigs from PMWS-affected farms. These results further support the results obtained from earlier in vitro and in vivo experimental models and suggest the association of specific PCV2 genogroups with diseased and nondiseased pigs in the field.