Phytochemical Composition and Biological Activity of Berries and Leaves from Four Romanian Sea Buckthorn (Hippophae Rhamnoides L.) Varieties.

Hippophae rhamnoides L. is an important source of natural antioxidant and antimicrobial agents. Phytochemical compounds, antioxidant and antibacterial properties of berries, and leaf extracts from four Romanian sea buckthorn cultivars were investigated. Large differences in the content of total polyphenols and flavonoids between the varieties were observed. HPLC analysis of the polyphenolic compounds showed greater differences in content in leaves than in berries. This study confirmed that sea buckthorn leaves and berries are a rich source of phenolic compounds, especially quercetin derivatives and hydrocinnamic acid derivatives. Five carotenoid compounds were identified in the berries: lutein, zeaxanthin, ß-cryptoxanthin, cis-ß-carotene, and ß-carotene. From the results obtained in this study, it can be stated that the varieties whose berries yielded the highest quantities of polyphenols, flavonoids, and antioxidant activity, can be ranked as follows: SF6 > Golden Abundant > Carmen > Colosal, and for leaf extracts the ranked order is SF6 > Golden Abundant > Colosal > Carmen. A strong correlation between the total flavonoid yield and antioxidant activity (r = 0.96), was observed. All extracts showed antibacterial activity against S. aureus, B. cereus, and P. aeruginosa, however extracts from berries were less potent than extracts from leaves.

CYP5122A1 encodes an essential sterol C4-methyl oxidase in Leishmania donovani and determines the antileishmanial activity of antifungal azoles.

Visceral leishmaniasis, caused by Leishmania donovani, is a life-threatening parasitic disease, but current antileishmanial drugs are limited and have severe drawbacks. There have been efforts to repurpose antifungal azole drugs for the treatment of Leishmania infection. Antifungal azoles are known to potently inhibit the activity of cytochrome P450 (CYP) 51 enzymes which are responsible for removing the C14α-methyl group of lanosterol, a key step in ergosterol biosynthesis in Leishmania. However, they exhibit varying degrees of antileishmanial activities in culture, suggesting the existence of unrecognized molecular targets for these compounds. Our previous study reveals that, in Leishmania, lanosterol undergoes parallel C4- and C14-demethylation reactions to form 4α,14α-dimethylzymosterol and T-MAS, respectively. In the current study, CYP5122A1 is identified as a sterol C4-methyl oxidase that catalyzes the sequential oxidation of lanosterol to form C4-oxidation metabolites. CYP5122A1 is essential for both L. donovani promastigotes in culture and intracellular amastigotes in infected mice. Overexpression of CYP5122A1 results in growth delay, differentiation defects, increased tolerance to stress, and altered expression of lipophosphoglycan and proteophosphoglycan. CYP5122A1 also helps to determine the antileishmanial effect of antifungal azoles in vitro. Dual inhibitors of CYP51 and CYP5122A1, e.g., clotrimazole and posaconazole, possess superior antileishmanial activity against L. donovani promastigotes whereas CYP51-selective inhibitors, e.g., fluconazole and voriconazole, have little effect on promastigote growth. Our findings uncover the critical biochemical and biological role of CYP5122A1 in L. donovani and provide an important foundation for developing new antileishmanial drugs by targeting both CYP enzymes.

Pathway-Based Metabolomics Analysis Reveals Biosynthesis of Key Flavor Compounds in Mango.

Mango is a tropical fruit with global demand as a result of its high sensory quality and nutritional attributes. Improving fruit quality at the consumer level could increase demand, but fruit quality is a complex trait requiring a deep understanding of flavor development to uncover key pathways that could become targets for improving sensory quality. Here, a pathway-based metabolomics (untargeted and targeted) approach was used to explore biosynthetic mechanisms of key flavor compounds with five core metabolic pathways (butanoate metabolism, phenylalanine biosynthesis and metabolism, terpenoid backbone biosynthesis, linoleic and linolenic acid pathway, and carbon fixation and sucrose metabolism) in three mango cultivars. The relationships between flavor precursors and flavor compounds were identified using correlation analysis. With these novel strategies, differentially regulated metabolic flux through the pathways was first elucidated, demonstrating possible mechanisms of key flavor formation and regulation in mango fruits.

Nontargeted metabolomics-based multiple machine learning modeling boosts early accurate detection for citrus Huanglongbing.

Early accurate detection of crop disease is extremely important for timely disease management. Huanglongbing (HLB), one of the most destructive citrus diseases, has brought about severe economic losses for the global citrus industry. The direct strategies for HLB identification, such as quantitative real-time polymerase chain reaction (qPCR) and chemical staining, are robust for the symptomatic plants but powerless for the asymptomatic ones at the early stage of affection. Thus, it is very necessary to develop a practical method used for the early detection of HLB. In this study, a novel method combining ultra-high performance liquid chromatography/mass spectrometry (UHPLC/MS)-based nontargeted metabolomics and machine learning (ML) was developed for conducting the early detection of HLB for the first time. Six ML algorithms were selected to build the classifiers. Regularized logistic regression (LR-L2) and gradient-boosted decision tree (GBDT) outperformed with the highest average accuracy of 95.83% to not only classify healthy and infected plants but identify significant features. The proposed method proved to be practical for early detection of HLB, which tackled the shortcomings of low sensitivity in the conventional methods and avoid the problems such as lighting condition interference in spectrum/image recognition-based ML methods. Additionally, the discovered biomarkers were verified by the metabolic pathway analysis and content change analysis, which was remarkably consistent with the previous reports.

Pulsed field gel electrophoresis typing of human and retail foodstuff Campylobacters: an Irish perspective.

Campylobacter enteritis is a zoonosis, an infectious disease transmissible under normal conditions from vertebrate animals to man, presenting a major global public health burden. In this study, Pulsed Field Gel Electrophoresis (PFGE) was employed to identify common genotypes in a collection of 600 Campylobacter isolates in order to investigate if profiles obtained from retail samples of foodstuffs matched genotypes causing illness in the community in Ireland. The Campylobacters were isolated from retail foodstuffs, and cases of gastroenteritis, over the same 20-month period in three population centres in Ireland. The major observation made was of a high level of PFGE-genotype heterogeneity; 236 SmaI discrete genotypes were found in 507 strains successfully analysed. Analysis of the PFGE profiles revealed 22 common profiles amongst food isolates and those causing enteritis in humans. These cojoint PFGE genotypes indicate that 56 (38%) of the human clinical isolates are genetically related to 129 (36%) of the food isolates. The identification of these recurrent PFGE types, in the sampled Campylobacter coli and Campylobacter jejuni populations, indicates that a high proportion of Campylobacter isolates found in foods of animal origin also occur in patients with symptoms of enteritis. This data adds weight to the epidemiological hypothesis that a high proportion of human Campylobacter cases are contracted via the handling and consumption of contaminated foodstuffs, in particular poultry.

Determination of changes in the microbial and chemical composition of Țaga cheese during maturation.

Țaga cheese is a traditional Romanian smear-ripened cheese made from bovine milk and identified with the name of the village and caves where it is produced. As no previously reported microbiological and chemical studies have been undertaken on this product, this research aimed to investigate the microbiological and biochemical characteristics which ensure the uniqueness of Țaga cheese during the ripening process, to inform producers as to key quality determinants. Cheese samples, consisting of retail blocks, were collected on days 2, 5, 12, 18, and 25 of the ripening process. The evolution of lactic microbiota during the production and maturation of traditional cheeses involves isolating lactic acid microorganisms present in cheese. Cheese samples were analyzed for pH, fat, NaCl, fatty acids, and volatile compounds. The microbial ecosystem naturally changes during the maturation process, leading to variation in the microorganisms involved during ripening. Our results show that specific bacteria were identified in high levels during the entire ripening process and may be responsible for milk fat lipolysis contributing directly to cheese flavor by imparting detailed fatty acid flavor notes, or indirectly as precursors formation of other flavor compounds.

Prevalence of Campylobacter spp. in raw retail poultry on sale in Northern Ireland.

A year-long survey of fresh, retail poultry products on sale in Northern Ireland was undertaken to define the prevalence of Campylobacter spp. by using protocols based on ISO (standard) 10272-1:2006. Incubation at 37 and 42 degrees C was undertaken to increase the diversity of isolates obtained. Overall, 652 isolates were identified as Campylobacter spp. by using PCR and amplified fragment length polymorphic typing. Phenotyping wrongly identified 21% of isolates. Prevalences of Campylobacter found were chicken, 91% (n = 336); turkey, 56% (n = 77); and duck, 100% (n = 17). Prevalence rates for chicken produced in Northern Ireland, Scotland, England, and Wales were similar, with a mean value of 91%. The prevalences in product from the latter two countries were much higher than were found in two United Kingdom-wide surveys of chicken. The incubation temperature did not affect the relative proportions of the species isolated (P > 0.05). Campylobacter jejuni composed 64.6% of isolates, Campylobacter coli, 27.4%, and Campylobacter lari, 1%. Most cases of human campylobacteriosis are caused by C. jejuni and C. coli. The overall Campylobacter prevalence results are consistent with Northern Ireland surveys undertaken since 2000, and indicate that United Kingdom strategies to control Campylobacter in chicken have not had a significant effecton the prevalence of this pathogen in retail products on sale in Northern Ireland.

Qualitative exposure assessment for Salmonella spp. in shell eggs produced on the island of Ireland.

A qualitative exposure assessment for Salmonella in eggs produced on the island of Ireland was developed. The assessment was divided into three main modules (production and packing, distribution and storage, and preparation and consumption), and each of these stages into defined steps in the exposure pathway. In the production and packing stage the initial prevalences of Salmonella in the contents and on the shell of eggs were estimated to be negligible and low respectively. Numbers of Salmonella both in and on eggs were estimated to be low. At each subsequent step in the pathway, qualitative assessments were made of the impact of events on the probability and level of Salmonella contamination on the shells and in the contents of eggs. At the end of each module assessments were combined to give an overall probability and level of Salmonella contamination. In the first two modules the assessment focused on the effect of the duration and temperature of storage on yolk membrane integrity and the likelihood of shell penetration. During the final stage the influence of factors such as safe-handling procedures, pooling practices, consumption patterns and the effectiveness of cooking, on the prevalence and level of Salmonella contamination in a food item at time of consumption was assessed. The outcome of this assessment was an estimate of a low probability and level of Salmonella contamination of egg-containing foods, prepared with eggs produced on the island of Ireland.

A comparison of media for the isolation of Arcobacter spp. from retail packs of beef.

In order to determine the most effective protocol for the isolation of Arcobacter spp. from retail packs of beef, three published methods (A, B, and C) were selected. In addition, a modified version of method B was studied (method D). The ability of the four methods to isolate Arcobacter from standardized beef samples (n = 80) was compared with presumptive Arcobacter isolates being identified to genus and species level, using multiplex PCR methods. The presence of Arcobacter in enrichment broths was also investigated using PCR techniques. Overall, the modified enrichment and selection media of Johnson and Murano (method D) gave the highest recovery of Arcobacter. Recovery using these media was enhanced by incubating the enrichment and selection media in a microaerobic cabinet rather than air, and the inclusion of streaking the enrichment broth onto selective agar after 24 h in addition to 48 h. Method D yielded significantly more Arcobacter-positive samples of beef (P < 0.01) than did the three other methods investigated.

Prevalence of Salmonella in grade A whole shell eggs in the island of Ireland.

Following the emergence of Salmonella Enteritidis as a widespread contaminant of eggs and the role of eggs in the transmission of human salmonellosis, control measures were introduced to curb the spread of infection. Two approaches to Salmonella control are currently used by egg producers in Ireland, because Northern Ireland producers, like those in the rest of the United Kingdom, widely adopted a vaccination regime, whereas the Republic of Ireland does not permit vaccination but introduced controls based on routine monitoring for specific Salmonella serovars and subsequent culling of infected flocks. To compare the efficacy of these two approaches and determine the prevalence of salmonellae in eggs produced for retail sale in the island of Ireland, a major survey of approximately 30,000 grade A eggs was undertaken. Egg shells and contents were analyzed separately for salmonellae by procedures based on International Organization for Standardization methodology. The survey yielded only two positive samples, with Salmonella Infantis and Salmonella Montevideo isolated from shells; no egg contents yielded salmonellae. There was no statistically significant difference in the prevalence of salmonellae between eggs produced in Northern Ireland and those from the Republic of Ireland; hence, both regimes appeared to be equally effective in controlling salmonellae. The prevalence was also significantly lower than that found in a recent major United Kingdom survey. Hence, shell eggs produced in the island of Ireland are unlikely to be a source of human salmonellosis.

Prevalence of Arcobacter spp. in raw milk and retail raw meats in Northern Ireland.

A 1-year study was undertaken to determine the prevalence of Arcobacter spp. in raw milk and retail raw meats on sale in Northern Ireland. Retail raw poultry samples (n = 94), pork samples (n = 101), and beef samples (n = 108) were obtained from supermarkets in Northern Ireland, and raw milk samples (n = 101) were kindly provided by the Milk Research Laboratory, Department of Agriculture and Rural Development, Belfast, Northern Ireland. Presumptive arcobacters were identified by previously described genus-specific and species-specific PCR assays. Arcobacter spp. were found to be common contaminants of retail raw meats and raw milk in Northern Ireland. Poultry meat (62%) had the highest prevalence, but frequent isolations were made from pork (35%), beef (34%), and raw milk (46%). Arcobacter butzleri was the predominant species isolated from retail raw meats and was the only species isolated from raw milk samples. Arcobacter cryaerophilus was detected less frequently, and Arcobacter skirrowii was detected only as a cocontaminant. To our knowledge, this is the first report of Arcobacter spp. prevalence in a diverse range of products of animal origin in Northern Ireland.

Breaking Bad News in obstetrics: a randomized trial of simulation followed by debriefing or lecture.

OBJECTIVE: Although communication skills represent an increasingly important aspect of medical care, little has been done to assess the best method of teaching these skills. Our study was designed to assess simulation-debriefing compared to lecture in teaching skills for Breaking Bad News (BBN) in obstetrics. METHODS: This is a randomized prospective trial of house staff from a large academic medical center. Subjects initially underwent baseline simulation, followed by evaluation on BBN skills by themselves, a faculty observer, and the standardized patient (SP). The subjects were then immediately randomized to a debriefing session by faculty or to a lecture about BBN. Subsequently, both groups underwent a second simulation with the same three assessments, yielding post-intervention data. RESULTS: 35 subjects completed both simulations. Both debriefing and lecture curricula showed improvement in scores by self (p = 0.010) and faculty (p < 0.001). The debriefing group improved significantly more than the lecture group for self-evaluation; additionally, improvements were greater for the debrief group in verbal and nonverbal skills. Long-term follow-up three months after both interventions demonstrated continued improvement in BBN. CONCLUSIONS: Simulation training with debriefing is effective for teaching communication skills, and superior to lecture for self-perceived improvement. Long-term follow-up suggested retention of confidence in BBN skills.

Seasonality in diurnal locomotory patterns of adult blacklegged ticks (Acari: Ixodidae).

We continuously recorded the activity of adult and nymphal blacklegged ticks, Ixodes scapularis Say, exposed to diurnal light and temperature cycles in a laboratory test chamber by using a digital camera controlled by an intervalometer. Adult ticks collected and tested in the fall exhibited a bimodal pattern of activity, with peaks shortly after lights on and shortly after lights off, and substantial daytime activity. However, adult ticks collected in the winter and early spring exhibited a unimodal pattern of activity, peaking shortly after lights off, and minimal daytime activity. Nymphs, collected and tested in the summer, exhibited only a unimodal pattern of activity, peaking after lights off. Limited data also are presented for adult ticks exposed to only a temperature cycle or to only a light cycle in the spring. Ticks exposed to a temperature cycle exhibited a unimodal pattern of activity, similar to that exhibited by ticks exposed to both light and temperature cycles at the same time of year, whereas those exposed to a light cycle exhibited a bimodal pattern of activity. Although the difference did not quite reach statistical significance, there is a possibility that temperature is a stronger entraining agent for tick diurnal activity than is light, an unusual situation. The change in diurnal activity pattern from fall to spring suggests that ticks are adjusting their strategy for host finding, possibly in relation to remaining stored food supplies or host activity, and may have practical implications for sampling carried out to track tick populations.

Virulence characteristics of hcp (+) Campylobacter jejuni and Campylobacter coli isolates from retail chicken.

BACKGROUND: Recently the Type VI secretion system (T6SS), which can play a significant role in bacterial survival and pathogenesis, was reported in Campylobacter spp., having the hcp gene as a key component. METHODS: Campylobacteriosis is associated with the consumption of infected chicken meat. Our study aimed to explore the presence of T6SS in C. jejuni (n = 59) and C. coli (n = 57) isolates, from retail raw chicken and to investigate their pathogenic potential. The hcp gene was used as an indicator for the T6SS presence. RESULTS: Using multiplex PCR we have identified a significantly higher prevalence of hcp in C. coli isolates (56.1%) than in C. jejuni (28.8%) and AFLP analysis of the isolates showed a high degree of genetic similarity between the isolates carrying the hcp gene. Genome sequencing data showed that 84.3% of the C. coli and 93.7% of the C. jejuni isolates had all 13 T6SS open reading frames. Moreover, the virulence characteristics of hcp + isolates, including motility and the ability to invade human intestinal epithelial cells in vitro, were significantly greater than in the control strain C. jejuni 12502; a human isolate which is hcp positive. CONCLUSION: Overall, it was discovered that hcp (+) C. coli and C. jejuni isolated from retail chicken isolates posses genetic and phenotypic properties associated with enhanced virulence. However, since human infections with C. coli are significantly less frequent than those of C. jejuni, the relationship between virulence factors and pathogenesis requires further study.

Decellularized cadaver vein allografts used for hemodialysis access do not cause allosensitization or preclude kidney transplantation.

BACKGROUND: Dimethyl sulfoxide-cryopreserved (CRY) cadaver vein allografts used for hemodialysis access in patients with renal failure recently have been shown to cause broad recipient allosensitization, measured by panel reactive antibody (PRA) assay. Synergraft (SYN) processing is a novel method of treating tissue that decellularizes the graft (including mismatched major histocompatibility antigens) and potentially should prevent allosensitization. METHODS: Twenty hemodialysis patients underwent placement of an SYN-processed cadaver vein allograft. PRA assay was used prospectively to assess allosensitization in these patients at baseline and 1-month intervals after engraftment. These results were compared with our historic series of CRY allograft recipients. RESULTS: There was no significant difference in baseline PRA values for SYN and CRY patients (2.8% versus 2.6%, respectively). None of the SYN patients became allosensitized at 3 months postengraftment (mean PRA, 3.2%), whereas all CRY recipients became highly sensitized at a mean of 3.1 months (mean PRA, 84.1%). This result was highly significant (P < 0.0001). CONCLUSION: SYN processing of cadaver vein allografts successfully removes antigenic material. The use of SYN allografts in patients with renal failure for hemodialysis access does not cause allosensitization and therefore should not preclude kidney transplantation.

Arterial misplacement of large-caliber cannulas during jugular vein catheterization: case for surgical management.

BACKGROUND: Accidental placement of a large sheath or catheter in an artery during central venous cannulation, though rare, is a potentially devastating complication. The present study reviews our 14-year experience with this complication to determine appropriate role of surgical management. STUDY DESIGN: Review was conducted of all cases involving patients treated by the vascular surgery service from July 1989 to June 2003 for accidental placement of a large-caliber cannula (>or= 7 F) in an artery during catheterization of the jugular vein. Two management techniques were used during this period: removal of cannula followed by application of local pressure; and surgical exploration, removal of cannula under direct vision, and repair of artery. RESULTS: Eleven patients (5 men, 6 women) aged 35 to 73 years (mean age 56 years) were treated for cannulas placed accidentally in an artery. In nine patients, the cannula entered the carotid artery, and in two patients it entered the subclavian artery. Three patients had undergone placement of 8.5-F sheaths for monitoring cardiac hemodynamics, and 8 patients had triple-lumen catheters for fluid infusion or parenteral nutrition. Eight patients (three sheath, five catheter) were asymptomatic at the time of cannula removal. In three patients, the correct diagnosis was missed initially and infusion was started. All three developed neurologic symptoms. In two patients, the cannula (sheath) was pulled and pressure applied. One of them developed a stroke and the other developed a pseudoaneurysm that was treated surgically. Nine patients in whom the sheath or catheter was removed by surgical exploration had no new complications related to surgery. CONCLUSIONS: Surgical management seems to be the most effective and safe treatment of arterial misplacement of cannulas during jugular vein catheterization. Further study is needed to determine the optimum management of this potentially devastating complication.

Comparison of eight phenotypic methods for subspecies characterization of thermophilic Campylobacter spp. isolated from pig liver.

Four hundred pork livers from bacon pigs (37 herds) obtained at six pig-processing plants were studied to assess the Campylobacter contamination rate. Deep tissue areas were sampled immediately after evisceration. Approximately 6% of livers were infected with Campylobacter spp., including Campylobacter coli (67%), Campylobacter jejuni (30%), and Campylobacter lari (3%). The 60 resulting isolates (39 C. coli isolates, 19 C. jejuni isolates, and 2 C. lari isolates) employed in this study were characterized at the subspecies level in a comparison of eight phenotyping schemes, including four biotyping, two serotyping, and two phage-typing schemes. The Skirrow-Benjamin biotyping scheme produced two biotypes for C. jejuni, i.e., biotype 2 (95%) and biotype 1 (5%). The Lior biotyping scheme subdivided C. coli into biotype 1 (41%) and biotype 2 (59%), while biotype 4 was the dominant type (95%) for C. jejuni. The Roop scheme allowed further differentiation of C. coli into three biovars, i.e., biovar 1 (57%), biovar 2 (40%), and biovar 3 (3%), and it subdivided C. jejuni into two biotypes, i.e., biovar 1 (95%) and biovar 2 (5%). Preston biotyping produced the largest degree of subspecies differentiation, with 18 C. coli biotypes and 7 C. jejuni biotypes being identified. The most common were biotypes 2650 and 6030, representing 18 and 42% of all C. coli and C. jejuni isolates, respectively. The Penner-Hennessy serotyping scheme successfully serotyped 89% of the isolates, with 10 serotypes being identified; 30% of the serotypeable isolates were accounted for by Penner 23, followed by Penner 20 (16%) and Penner 39 (14%). The Lior serotyping scheme successfully serotyped only 45% of the strains, and eight serogroups were identified, with Lior 36 (31%), Lior 20 (23%), and Lior 5 being the most frequent. The Preston scheme and the Khakhria-Lior phage-typing scheme were able to type 16 and 25% of the isolates, respectively. The Preston scheme produced three phage groups, i.e., 69 (56%), 90 (22%), and 116 (22%), and the Khakhria-Lior scheme also produced three phage types, i.e., 44 (40%), 27 (33%), and 37 (20%), as well as atypical lysis patterns (7%). The results of this study demonstrate the role of Preston biotyping in the phenotyping of isolates, particularly in diagnostic laboratories that have no access or limited access to molecular typing equipment.

Impediometric detection of Campylobacter coli.

The rapid automated bacterial impedance technique (RABIT) was examined as a method for the detection of two wild-type isolates of Campylobacter coli in broth media. Both isolates failed to produce a change in impedance that was sufficient for detection in any combination of six nonselective basal broth media, including Mueller-Hinton broth, nutrient broth no. 2, brain heart infusion broth supplemented with yeast extract (0.5% [wt/vol]), brucella broth, Campy broth supplemented with yeast extract (0.5% [wt/voll), and Whitley impedance broth, at 37 and 42 degrees C. Although the strains did proliferate in the media, changes in conductivity were very small (ranging from 0 to 1,000 microS) and were not significantly greater than the drift in conductance observed in the control broth medium. Additional work is therefore required to define a nonionic growth substrate that will produce charged ions upon metabolism that are detectable by RABIT.

A comparison of three methods for the isolation of Arcobacter spp. from retail raw poultry in Northern Ireland.

Recent evidence suggests that arcobacters, especially Arcobacter butzleri, are potential foodborne pathogens, but standardized detection methods have yet to be established. A study was undertaken to determine which of three isolation methods was the most effective for the isolation of Arcobacter spp. from fresh raw poultry. Methods 1 was microaerobic and involved a membrane filtration step followed by plating onto blood agar. Method 2 was also microaerobic and involved enrichment and plating media containing a five-antibiotic cocktail. Method 3 was aerobic and was based on enrichment in a charcoal-based broth containing two antibiotics. Retail poultry samples (n = 50) were obtained from supermarkets in Northern Ireland; the European Community license number was recorded to ensure sample diversity. Presumptive arcobacters were identified using genus-specific and species-specific primers. Methods 1 resulted in the lowest recovery of arcobacters (28% of samples positive). The detection rate for method 2 (68%) was higher than that for method 3 (50%), but the difference was not significant (P > 0.05). Modification of method 3 by plating the enrichment broth at 24 h, as well as at 48 h, increased recovery to 68%. Use of methods 2 and 3 together increased the number of positive samples detected by approximately 25% compared with use of either method alone. A. butzleri was the most commonly isolated species using all methods. Method 3 detected Arcobacter cryaerophilus in more samples (n = 3) than did method 1 and 2 (n = 1). Arcobacter skirrowii was detected by only method 3 (n = 1). In terms of sensitivity, ease of use, and diversity of species recovered, modified method 3 was the overall method of choice.

Determination of the principal points of product contamination during beef carcass dressing processes in Northern Ireland.

To determine the principal points of microbial contamination of carcasses during beef carcass dressing in Northern Ireland, 190 carcasses were sampled by swabbing 1,000 cm2 of the brisket. A detailed survey of one abattoir was initially conducted, with sampling of a total of 100 carcasses immediately after hide removal (H), after carcass splitting (S), and immediately after washing (W) before dispatch to the chiller. The total bacterial counts after incubation at both 22 and 37 degrees C indicated that there was no significant increase in the numbers of bacteria after the first sampling point, H (P > 0.05). To determine whether this was the case in the majority of Northern Ireland abattoirs, 15 carcasses were then sampled at each of an additional six abattoirs, at points H and W only. Total bacterial counts were significantly higher (P < 0.05) at H than at W, indicating that hide pulling was the major point of bacterial contamination of beef carcasses and hence a critical control point for the final microbiological quality of the carcasses. Mean counts of Enterobacteriaceae at both incubation temperatures were very low (< 10 CFU/cm2) but were higher at W than at H, probably indicating that washing was redistributing bacteria from the posterior to the anterior region.