Arcobacter butzleri in Sheep Ricotta Cheese at Retail and Related Sources of Contamination in an Industrial Dairy Plant

This study aimed to evaluate Arcobacter species contamination of industrial sheep ricotta cheese purchased at retail and to establish if the dairy plant environment may represent a source of contamination. A total of 32 sheep ricotta cheeses (1.5 kg/pack) packed in a modified atmosphere were purchased at retail, and 30 samples were collected in two sampling sessions performed in the cheese factory from surfaces in contact with food and from surfaces not in contact with food. Seven out of 32 samples (21.9%) of ricotta cheese collected at retail tested positive for Arcobacter butzleri at cultural examination; all positive samples were collected during the same sampling and belonged to the same batch. Ten surface samples (33.3%) collected in the dairy plant were positive for A. butzleri. Cluster analysis identified 32 pulsed-field gel electrophoresis (PFGE) patterns. The same PFGE pattern was isolated from more than one ricotta cheese sample, indicating a common source of contamination, while more PFGE patterns could be isolated in single samples, indicating different sources of contamination. The results of the environmental sampling showed that A. butzleri may be commonly isolated from the dairy processing plant investigated and may survive over time, as confirmed by the isolation of the same PFGE pattern in different industrial plant surface samples. Floor contamination may represent a source of A. butzleri spread to different areas of the dairy plant, as demonstrated by isolation of the same PFGE pattern in different production areas. Isolation of the same PFGE pattern from surface samples in the dairy plant and from ricotta cheese purchased at retail showed that plant surfaces may represent a source of A. butzleri postprocessing contamination in cheeses produced in industrial dairy plants.     

Adherence to and Invasion of Human Intestinal Cells by Arcobacter Species and Their Virulence Genotypes

The genus Arcobacter is composed of 17 species which have been isolated from various sources. Of particular interest are A. butzleri, A. cryaerophilus, and A. skirrowii, as these have been associated with human cases of diarrhea, the probable transmission routes being through the ingestion of contaminated drinking water and food. To date, only limited studies of virulence traits in this genus have been undertaken. The present study used 60 Arcobacter strains isolated from different sources, representing 16 of the 17 species of the genus, to investigate their ability to adhere to and invade the human intestinal cell line Caco-2. In addition, the presence of five putative virulence genes (ciaB, cadF, cj1349, hecA, and irgA) was screened for in these strains by PCR. All Arcobacter species except A. bivalviorum and Arcobacter sp. strain W63 adhered to Caco-2 cells, and most species (10/16) were invasive. The most invasive species were A. skirrowii, A. cryaerophilus, A. butzleri, and A. defluvii. All invasive strains were positive for ciaB (encoding a putative invasion protein). Other putative virulence genes were present in other species, i.e., A. butzleri (cadF, cj1349, irgA, and hecA), A. trophiarum (cj1349), A. ellisii (cj1349), and A. defluvii (irgA). No virulence genes were detected in strains which showed little or no invasion of Caco-2 cells. These results indicate that many Arcobacter species are potential pathogens of humans and animals.     

Detection of Arcobacter spp. in the Coastal Environment of the Mediterranean Sea

The occurrence of Arcobacter spp. was studied in seawater and plankton samples collected from the Straits of Messina, Italy, during an annual period of observation by using cultural and molecular techniques. A PCR assay with three pairs of primers targeting the 16S and 23S rRNA genes was used for detection and identification of Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii in cultures and environmental samples. Only one of the Arcobacter species, A. butzleri, was isolated from seawater and plankton samples. With some samples the A. butzleri PCR assay gave amplified products when cultures were negative. A. cryaerophilus and A. skirrowii were never detected by culture on selective agar plates; they were detected only by PCR performed directly with environmental samples. Collectively, our data suggest that culturable and nonculturable forms of Arcobacter are present in marine environments. The assay was useful for detecting Arcobacter spp. both as free forms and intimately associated with plankton. This is the first report showing both direct isolation of A. butzleri and the presence of nonculturable Arcobacter spp. in the coastal environment of the Mediterranean Sea.     

Amount and variation of strip yields collected by a defined hand-milking method after machine milking of Holstein dairy cows

Hand-milking methods to assess the completeness of milking in dairy cows need to be reliable as well as quick to apply in order to avoid delays in group milking parlours. A previous study comparing different methods demonstrated that a defined milking handgrip with a strip frequency of 1 Hz was most suitable to assess the completeness of milk-out in dairy cows. In a first step, the present study aimed to investigate how much milk can be hand-milked by the defined handgrip, strip frequency and within a time limit of 15 s per quarter. In a second step, the question was how many udder quarters of a cow needed to be hand-milked for a reliable prediction of the amount of rest milk in the udder. The experiment comprised 28 German-Holstein cows of one herd. The cows were hand-milked after cluster detachment by an experienced milker using the defined milking handgrip. All four quarters per cow were hand-milked during nine consecutive milking sessions. The strip yield per quarter per 15 s hand-milking (SY15) was collected in four different containers and weighed with a digital scale. Afterwards, the remaining milk of all four quarters was collected and weighed in a fifth container with a maximum volume equivalent to a net weight of 540 g milk. The analysis showed that neither the position of the quarter nor the chronological order, in which hand-milking was carried out, had an influence on SY15. The amount of rest milk in the udder could be estimated best by hand-milking all four quarters.     

Robot utilisation of pasture-based dairy cows with varying levels of milking frequency

Achieving a consistent level of robot utilisation throughout 24 h maximises automatic milking system (AMS) utilisation. However, levels of robot utilisation in the early morning hours are typically low, caused by the diurnal feeding behaviour of cows, limiting the inherent capacity and total production of pasture-based AMS. Our objective was to determine robot utilisation throughout 24 h by dairy cows, based on milking frequency (MF; milking events per animal per day) in a pasture-based AMS. Milking data were collected from January and February 2013 across 56 days, from a single herd of 186 animals (Bos taurus) utilising three Lely A3 robotic milking units, located in Tasmania, Australia. The dairy herd was categorised into three equal sized groups (n=62 per group) according to the cow’s mean daily MF over the duration of the study. Robot utilisation was characterised by an interaction (P< 0.001) between the three MF groups and time of day, with peak milking time for high MF cows within one h of a fresh pasture allocation becoming available, followed by the medium MF and low MF cows 2 and 4 h later, respectively. Cows in the high MF group also presented for milking between 2400 and 0600 h more frequently (77% of nights), compared to the medium MF group (57%) and low MF group (50%). This study has shown the formation of three distinct groups of cows within a herd, based on their MF levels. Further work is required to determine if this finding is replicated across other pasture-based AMS farms.     

Presence and quantification of pathogenic Arcobacter and Campylobacter species in retail meats available in Japan

We present estimations for the amounts of Arcobacter (A. butzleri, A. cryaerophilus and A. skirrowii) and Campylobacter (C. jejuni, C. coli and C. fetus) species in retail chicken, pork and beef meat using PCR-MPN. Arcobacter butzleri, A. cryaerophilus and C. jejuni were found in 100, 60 and 55% of chicken samples, respectively. No other Arcobacter or Campylobacter species were found in chicken. The MPNs of A. butzleri, A. cryaerophilus and C. jejuni were greater than 10³ per 100 g in 50, 0 and 5% of samples, respectively. The MPN of A. butzleri was higher than that of C. jejuni in 95% of samples. In pork, A. butzleri and A. cryaerophilus were detected in 10 and 11 (50 and 55%) of 20 samples, respectively. No other Arcobacter or Campylobacter species were found in pork. Only one pork sample had more than 10³ MPN per 100 g of A. cryaerophilus. For beef, only two samples tested positive for A. cryaerophilus, at 4600 and 92 MPN per 100 g. Overall, we found that the presence and MPNs of Arcobacter species are very high in chicken. In contrast, the positive ratios of Arcobacter in pork were high as chicken samples, but MPNs were lower than in chicken.     

Are dairy cows with a more reactive temperament less efficient in energetic metabolism and do they produce more enteric methane?

It remains unknown whether dairy cows with more reactive temperament produce more enteric methane (CH₄) and are less bioenergetically efficient than the calmer ones. The objectives of this study were (a) to evaluate the relationship between cattle temperament assessed by traditionally used tests with energetic metabolism and enteric CH₄ emissions by crossbred dairy cows; (b) to assess how cows’ restlessness in respiration chambers affects energetic metabolism and enteric CH₄ emissions. Temperament indicators were evaluated for 28 primiparous F1 Holstein-Gyr cows tested singly in the handling corral (entrance time, crush score, flight speed, and flight distance) and during milking (steps, kicks, defecation, rumination, and kick the milking cluster off). Cows’ behaviors within respiration chambers were also recorded for each individual kept singly. Digestibility and calorimetry trials were performed to obtain energy partitioning and CH₄ measures. Cows with more reactive temperament in milking (the ones that kicked the milking cluster off more frequently) spent 25.24% less net energy on lactation (P = 0.04) and emitted 36.77% more enteric CH₄/kg of milk (P = 0.03). Furthermore, cows that showed a higher frequency of rumination at milking parlor allocated 57.93% more net energy for milk production (P < 0.01), spent 50.00% more metabolizable energy for milk production (P < 0.01) and 37.10% less CH₄/kg of milk (P = 0.04). Regarding the handling temperament, most reactive cows according to flight speed, lost 29.16% less energy as urine (P = 0.05) and tended to have 14.30% more enteric CH₄ production (P = 0.08), as well as cows with a lower entrance time (most reactive) that also lost 13.29% more energy as enteric CH₄ (P = 0.04). Temperament and restless behavior of Holstein-Gyr cows were related to metabolic efficiency and enteric CH₄ emissions. Cows’ reactivity and rumination in the milking parlor, in addition to flight speed and entrance time in the squeeze chute during handling in the corral, could be useful measures to predict animals more prone to metabolic inefficiency, which could negatively affect the sustainability of dairy systems.     

Source of Enterococci in a Farmhouse Raw-Milk Cheese

Enterococci are widely distributed in raw-milk cheeses and are generally thought to positively affect flavor development. Their natural habitats are the human and animal intestinal tracts, but they are also found in soil, on plants, and in the intestines of insects and birds. The source of enterococci in raw-milk cheese is unknown. In the present study, an epidemiological approach with pulsed-field gel electrophoresis (PFGE) was used to type 646 Enterococcus strains which were isolated from a Cheddar-type cheese, the milk it was made from, the feces of cows and humans associated with the cheese-making unit, and the environment, including the milking equipment, the water used on the farm, and the cows' teats. Nine different PFGE patterns, three of Enterococcus casseliflavus, five of Enterococcus faecalis, and one of Enterococcus durans, were found. The same three clones, one of E. faecalis and two of E. casseliflavus, dominated almost all of the milk, cheese, and human fecal samples. The two E. casseliflavus clones were also found in the bulk tank and the milking machine even after chlorination, suggesting that a niche where enterococci could grow was present and that contamination with enterococci begins with the milking equipment. It is likely but unproven that the enterococci present in the human feces are due to consumption of the cheese. Cow feces were not considered the source of enterococci in the cheese, as Enterococcus faecium and Streptococcus bovis, which largely dominated the cows' intestinal tracts, were not found in either the milk or the cheese.     

IgG1 variations in the colostrum of Holstein dairy cows

High-immune quality colostrum (IgG1 concentration ⩾50 g/l) is crucial for the health and development of the young calf. Studies on colostrum quality tend to focus on external factors such as breed, parity or dry period length, but few have focused on within-cow variations. Here we ran experiments to gain a deeper insight into within-cow variation in IgG1 concentrations in dairy cow colostrum. Trials were performed in an experimental farm, located in the Western part of France. Colostrum from each quarter and a composite sample (mix of four quarters) were concomitantly collected on 77 Holstein dairy cows just after calving to assess the influence of sample type on IgG1 concentrations. Variation in IgG1 concentrations during the first milking was studied on samples from nine cows collected every minute from the start of milking. Repeatability of colostral IgG1 concentration was estimated from 2009 and 2010 data on 16 healthy cows. IgG1 concentrations were tested using a radial immunodiffusion method. Sensitivity and specificity were similar regardless of sample type tested (individual quarter or composite milk). Mean average IgG1 concentration was 54.1 g/l in composite colostrum, and was significantly higher in hind quarter teats (56.2 g/l) than front quarter teats (53.1 g/l). Average IgG1 concentration did not change significantly during colostrum milking, and the variations observed (15% or less) were likely due to the laboratory method (CV 15%). IgG1 concentrations in dam colostrum increased slightly from 2009 to 2010 due to BW and parity effects. In 56% of cases, colostrum quality could have been assessed on either individual or composite colostrum samples collected at any time during the first milking without affecting the reliability of the measurement. However, in other cases, differences were significant enough to mean that estimates of average IgG1 concentration in colostrum from any one quarter would not be reliable. It is concluded that colostrum quality, from an IgG1 concentration point of view, could be assessed with a composite sample taken at any time during the first milking.     

Economic analysis of the use of in vitro produced embryos transferred during heat stress under dairy herd constraints

The use of embryo transfer helps to improve reproductive performance during periods of heat stress. In vitro produced embryo transfer (IVP-ET) is more expensive than artificial insemination. We hypothesized that the value IVP-ET in seasonal herds depends on herd constraints, such as the maximum number of milking cows and the maximum number of calvings that can be accommodated throughout the year. Therefore, the objective of this study was to estimate how profitability in dairy herds exposed to summer heat stress is affected by the number of months in which IVP-ET is used, the use of IVP-ET in repeat-breeder cows, IVP-ET cost, and herd constraints. We built and used a nonlinear programming model of a dairy herd with young stock and cows with monthly Markov Chain transitions. The model varied the number of heifers calving in each calendar month to maximize herd profitability. We varied IVP-ET cost ($100 or $200), duration of the IVP-ET program (2 or 4 months), and the breeding number in which IVP-ET started (1st or 3rd). In total, 20 scenarios were simulated. Maximum profitability was obtained when IVP-ET was not used, regardless of herd constraints. The 16 scenarios in which IVP-ET was used showed increased seasonality in milk yield, numbers of milking cows, total cows, total calvings, and heifer calvings because the program tried to limit the number of IVP-ET breedings in the summer. The addition of the calving constraint increased the value of IVP-ET. The breakeven cost per IVP-ET ranged from −$6.79 to $24.38 compared with conventional semen cost of $20. In conclusion, the current market costs of IVP-ET did not warrant application with the objective to increase reproductive performance during heat stress. Herd constraints on the maximum allowable seasonality in the monthly number of milking cows and calvings affected the value of IVP-ET during heat stress.     

Occurrence,Diversity, and Host Association of Intestinal Campylobacter,Arcobacter, and Helicobacter in Reptiles

Campylobacter, Arcobacter, and Helicobacter species have been isolated from many vertebrate hosts, including birds, mammals, and reptiles. Multiple studies have focused on the prevalence of these Epsilonproteobacteria genera in avian and mammalian species. However, little focus has been given to the presence within reptiles, and their potential zoonotic and pathogenic roles. In this study, occurrence, diversity, and host association of intestinal Epsilonproteobacteria were determined for a large variety of reptiles. From 2011 to 2013, 444 cloacal swabs and fecal samples originating from 417 predominantly captive-held reptiles were screened for Epsilonproteobacteria. Campylobacter, Arcobacter, and Helicobacter genus specific PCRs were performed directly on all samples. All samples were also cultured on selective media and screened for the presence of Epsilonproteobacteria. Using a tiered approach of AFLP, atpA, and 16S rRNA sequencing, 432 Epsilonproteobacteria isolates were characterized at the species level. Based on PCR, Campylobacter, Arcobacter, and Helicobacter were detected in 69.3% of the reptiles; 82.5% of the chelonians, 63.8% of the lizards, and 58.0% of the snakes were positive for one or more of these genera. Epsilonproteobacteria were isolated from 22.1% of the reptiles and were isolated most frequently from chelonians (37.0%), followed by lizards (19.6%) and snakes (3.0%). The most commonly isolated taxa were Arcobacter butzleri, Arcobacter skirrowii, reptile-associated Campylobacter fetus subsp. testudinum, and a putative novel Campylobacter taxon. Furthermore, a clade of seven related putative novel Helicobacter taxa was isolated from lizards and chelonians. This study shows that reptiles carry various intestinal Epsilonproteobacteria taxa, including several putative novel taxa.     

Histopathological and parasitological study of the gastrointestinal tract of dogs naturally infected with Leishmania infantum

Background

A nationwide survey on the microbial etiology of cases of subclinical mastitis in dairy cows was carried out on dairy farms in Sweden. The aim was to investigate the microbial panorama and the occurrence of antimicrobial resistance. Moreover, differences between newly infected cows and chronically infected cows were investigated.

Methods

In total, 583 quarter milk samples were collected from 583 dairy cows at 226 dairy farms from February 2008 to February 2009. The quarter milk samples were bacteriological investigated and scored using the California Mastitis Test. Staphylococci were tested for betalactamase production and presence of resistance was evaluated in all specific udder pathogens. Differences between newly infected cows and chronically infected cows were statistically investigated using logistic regression analysis.

Results

The most common isolates of 590 bacteriological diagnoses were Staphylococcus (S) aureus (19%) and coagulase-negative staphylococci (CNS; 16%) followed by Streptococcus (Str) dysgalactiae (9%), Str. uberis (8%), Escherichia (E.) coli (2.9%), and Streptococcus spp. (1.9%). Samples with no growth or contamination constituted 22% and 18% of the diagnoses, respectively. The distribution of the most commonly isolated bacteria considering only bacteriological positive samples were: S. aureus - 31%, CNS - 27%, Str. dysgalactiae - 15%, Str. uberis - 14%, E. coli - 4.8%, and Streptococcus spp. - 3.1%. There was an increased risk of finding S. aureus, Str. uberis or Str. dysgalactiae in milk samples from chronically infected cows compared to findings in milk samples from newly infected cows. Four percent of the S. aureus isolates and 35% of the CNS isolates were resistant to penicillin G. Overall, resistance to other antimicrobials than penicillin G was uncommon.

Conclusions

Staphylococcus aureus and CNS were the most frequently isolated pathogens and resistance to antimicrobials was rare.     

Epidemiologic study of environmental sources in a Prototheca zopfii outbreak of bovine mastitis

Bovine mastitis represents the main form of occurrence of protothecosis in animals. The detection of mastitis caused by Prototheca sp. indicates a serious problem which can affect an entire herd. The purpose of this study is to explain some aspects of the epidemiology of mastitis due to Prototheca zopfii with the evaluation of the presence of these microorganisms in samples collected from potential sources in the dairy herd. This study was performed during a Prototheca zopfii outbreak of clinical bovine mastitis in the State of São Paulo, Brazil. The following samples were aseptically collected for microbiological examination: milk (n = 211); rectal swabs (from 15 calves and 2 lactating cows); swabs from teat cup rubbers during milking (n = 2); water (n = 6); soil (n = 6). Prototheca zopfii was isolated from 77 (36.49%) of the 211 milk samples; 11 calves and 2 cows showed Prototheca zopfii in faecal samples; both swabs collected from the teat cup rubbers showed viable forms of Prototheca zopfii; this microorganism was also isolated from 2 water samples, and 1 soil sample collected from the dry cow pasture. Prototheca zopfii seemed to be widespread throughout the dairy herd environment where this outbreak of bovine mastitis occurred.This revised version was published online in October 2005 with corrections to the Cover Date.     

Presence and Analysis of Plasmids in Human and Animal Associated Arcobacter Species

In this study, we report the screening of four Arcobacter species for the presence of small and large plasmids. Plasmids were present in 9.9% of the 273 examined strains. One Arcobacter cryaerophilus and four Arcobacter butzleri plasmids were selected for further sequencing. The size of three small plasmids isolated from A. butzleri and the one from A. cryaerophilus strains ranged between 4.8 and 5.1 kb, and the size of the large plasmid, isolated from A. butzleri, was 27.4 kbp. The G+C content of all plasmids ranged between 25.4% and 26.2%. A total of 95% of the large plasmid sequence represents coding information, which contrasts to the 20 to 30% for the small plasmids. Some of the open reading frames showed a high homology to putative conserved domains found in other related organisms, such as replication, mobilization and genes involved in type IV secretion system. The large plasmid carried 35 coding sequences, including seven genes in a contiguous region of 11.6 kbp that encodes an orthologous type IV secretion system found in the Wolinella succinogenes genome, Helicobacter pylori and Campylobacter jejuni plasmids, which makes this plasmid interesting for further exploration.     

Genetic and non-genetic factors associated with milking order in lactating dairy cows

The ability to rapidly identify temporal deviations of an animal from its norm will be important in the management of individual cows in large herds. Furthermore, predictors of genetic merit for especially health traits are useful to augment the accuracy of selection, and thus genetic gain, in breeding programs. The objective of this study was to estimate the repeatability of milking order and to quantify the contribution of differences in additive genetic variation to phenotypic differences (i.e., heritability). The data used in this study included 9813 herd milk recording test-day records with time of milking from 85,532 cows in 1143 herds across an 8-year period. Milking order was available for both morning and evening milking for each cow with, on average, 3.33 milk test-day records (i.e., 6.66 milking events) per lactation, and on average 1.62 lactations per cow. Variance components for milking order were estimated using animal linear mixed models; covariance components between milking order and milk yield, milk composition and somatic cell score (i.e., logarithm₁₀ somatic cell count) were estimated also using animal linear mixed models. The heritability of milking order was 0.20 indicating partial genetic control of milking order. The repeatability of milking order within test-day, within lactation, and across lactations was 0.63, 0.51, and 0.47, respectively. Milking order was positively (P < 0.001), but weakly, phenotypically correlated with milk yield (r = 0.04), and milk fat concentration (r = 0.01) and negatively (P < 0.001), but weakly, correlated with milk protein concentration (r = −0.02) and somatic cell score (r = −0.05). Milking order was positively (P < 0.05), although weakly, genetically correlated with milk yield (r = 0.07) and negatively (P < 0.05), but also weakly, genetically correlated with somatic cell score (r = −0.08). This study is the first to show a contribution of additive genetics to milking order in dairy cattle but the genetic correlation between milking order and somatic cell score was weak.     

Production,partial cash flows and greenhouse gas emissions of simulated dairy herds with extended lactations

The transition period is the most critical period in the lactation cycle of dairy cows. Extended lactations reduce the frequency of transition periods, the number of calves and the related labour for farmers. This study aimed to assess the impact of 2 and 4 months extended lactations on milk yield and net partial cash flow (NPCF) at herd level, and on greenhouse gas (GHG) emissions per unit of fat- and protein-corrected milk (FPCM), using a stochastic simulation model. The model simulated individual lactations for 100 herds of 100 cows with a baseline lactation length (BL), and for 100 herds with lactations extended by 2 or 4 months for all cows (All+2 and All+4), or for heifers only (H+2 and H+4). Baseline lactation length herds produced 887 t (SD: 13) milk/year. The NPCF, based on revenues for milk, surplus calves and culled cows, and costs for feed, artificial insemination, calving management and rearing of youngstock, was k€174 (SD: 4)/BL herd per year. Extended lactations reduced milk yield of the herd by 4.1% for All+2, 6.9% for All+4, 1.1% for H+2 and 2.2% for H+4, and reduced the NPCF per herd per year by k€7 for All+2, k€12 for All+4, k€2 for H+2 and k€4 for H+4 compared with BL herds. Extended lactations increased GHG emissions in CO₂-equivalents per t FPCM by 1.0% for All+2, by 1.7% for All+4, by 0.2% for H+2 and by 0.4% for H+4, but this could be compensated by an increase in lifespan of dairy cows. Subsequently, production level and lactation persistency were increased to assess the importance of these aspects for the impact of extended lactations. The increase in production level and lactation persistency increased milk production of BL herds by 30%. Moreover, reductions in milk yield for All+2 and All+4 compared with BL herds were only 0.7% and 1.1% per year, and milk yield in H+2 and H+4 herds was similar to BL herds. The resulting NPCF was equal to BL for All+2 and All+4 and increased by k€1 for H+2 and H+4 due to lower costs for insemination and calving management. Moreover, GHG emissions per t FPCM were equal to BL herds or reduced (0% to −0.3%) when lactations were extended. We concluded that, depending on lactation persistency, extending lactations of dairy cows can have a positive or negative impact on the NPCF and GHG emissions of milk production.     

Mycobacterium avium Subspecies paratuberculosis Cultured from Locally and Commercially Pasteurized Cow's Milk in the Czech Republic

Between November 2002 and April 2003, 244 bottles and cartons of commercially pasteurized cow's milk were obtained at random from retail outlets throughout the Czech Republic. During the same period, samples of raw milk and of milk that was subsequently subjected to a minimum of 71.7°C for 15 s in a local pasteurization unit were also obtained from two dairy herds, designated herds A and B, with low and high levels, respectively, of subclinical Mycobacterium avium subsp. paratuberculosis infection, and from one herd, herd C, without infection. Infection in individual cows in each herd was tested by fecal culturing. Milk samples were brought to the Veterinary Research Institute in Brno, Czech Republic, processed, inoculated onto Herrold's egg yolk slants, and incubated for 32 weeks. Colonies were characterized by morphology, Ziehl-Neelsen staining, mycobactin J dependency, and IS900 PCR results. M. avium subsp. paratuberculosis was cultured from 4 of 244 units (1.6%) of commercially pasteurized retail milk. M. avium subsp. paratuberculosis was also cultured from 2 of 100 (2%) cartons of locally pasteurized milk derived from infected herds A and B and from 0 of 100 cartons of milk from uninfected herd C. Raw milk from 1 of 10 (10%) fecal culture-positive cows in herd A and from 13 of 66 (19.7%) fecal culture-positive cows in herd B was culture positive for M. avium subsp. paratuberculosis. These findings confirm that M. avium subsp. paratuberculosis is present in raw milk from subclinically infected dairy cows. The culture of M. avium subsp. paratuberculosis in the Czech Republic from retail milk that had been pasteurized locally or commercially to the required national and European Union standards is in agreement with similar research on milk destined for consumers in the United Kingdom and the United States and shows that humans are being exposed to this chronic enteric pathogen by this route.     

Arcobacter butzleri Induce Colonic,Extra-Intestinal and Systemic Inflammatory Responses in Gnotobiotic IL-10 Deficient Mice in a Strain-Dependent Manner

Background

The immunopathological impact of human Arcobacter (A.) infections is under current debate. Episodes of gastroenteritis with abdominal pain and acute or prolonged watery diarrhea were reported for A. butzleri infected patients. Whereas adhesive, invasive and cytotoxic capacities have been described for A. butzleri in vitro, only limited information is available about the immunopathogenic potential and mechanisms of infection in vivo.

Methodology/Principal Findings

Gnotobiotic IL-10^-/- mice were generated by broad-spectrum antibiotic treatment and perorally infected with the A. butzleri strains CCUG 30485 and C1 shown to be invasive in cell culture assays. Bacterial colonization capacities, clinical conditions, intestinal, extra-intestinal and systemic immune responses were monitored at day six and 16 postinfection (p.i.). Despite stable intestinal A. butzleri colonization at high loads, gnotobiotic IL-10^-/- mice were virtually unaffected and did not display any overt symptoms at either time point. Notably, A. butzleri infection induced apoptosis of colonic epithelial cells which was paralleled by increased abundance of proliferating cells. Furthermore A. butzleri infection caused a significant increase of distinct immune cell populations such as T and B cells, regulatory T cells, macrophages and monocytes in the colon which was accompanied by elevated colonic TNF, IFN-γ, nitric oxide (NO), IL-6, IL-12p70 and MCP-1 concentrations. Strikingly, A. butzleri induced extra-intestinal and systemic immune responses as indicated by higher NO concentrations in kidney and increased TNF, IFN-γ, IL-12p70 and IL-6 levels in serum samples of infected as compared to naive mice. Overall, inflammatory responses could be observed earlier in the course of infection by the CCUG 30485 as compared to the C1 strain.

Conclusion/Significance

Peroral A. butzleri infection induced not only intestinal but also extra-intestinal and systemic immune responses in gnotobiotic IL-10^-/- mice in a strain-dependent manner. These findings point towards an immunopathogenic potential of A. butzleri in vertebrate hosts.     

Antimicrobial resistance and virulence genes profiles of Arcobacter butzleri strains isolated from back yard chickens and retail poultry meat in Chile

This research aims to investigate the presence and pathogenic potential of Arcobacter in poultry meat samples purchased in the retail market of Valdivia (South of Chile) as well as in faecal samples from backyard chickens from rural areas around this city. The isolates obtained were identified by molecular methods. Furthermore, putative virulence genes were assessed by PCR and the antimicrobial resistance was tested by phenotypic methods. Arcobacter was present in 41·6% of the samples, with the highest value in retail poultry meat (55·7%) followed by backyard production (28·0%). Arcobacter butzleri was the most prevalent species (75·6%) followed by Arcobacter skirrowii (14·8%) and Arcobacter cryaerophilus (9·6%). An 8·5% of A. butzleri strains from meat were resistant to both ciprofloxacin and tetracycline and 6·1% were resistant to erythromycin, while none was resistant to gentamycin, unlike strains from domestic chickens, which showed no resistance. Furthermore, A. butzleri strains from chicken meat presented a higher prevalence of virulence genes than strains from domestic chickens. In fact, in this last group, some genes (hecA, hecB and irgA) were completely absent. Therefore, this study provides insight on the epidemiology of Arcobacter in Chilean poultry and suggests that under traditional breeding conditions strains are, apparently, less pathogenic and drug resistant.