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Copyright of Agronomía & Ambiente is the property of Universidad de Buenos Aires. Facultad de Agronomia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to perform a quantitative microbial risk assessment (QMRA) of Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (STEC-HUS) linked to the consumption of Kosher beef produced in Argentina and consumed in Israel in children under 14 years. A probabilistic risk assessment model was developed to characterize STEC prevalence and contamination levels in the beef supply chain (cattle primary production, cattle transport, processing and storage in the abattoir, for export and at retail, and home preparation and consumption). The model was implemented in Microsoft Excel 2016 with the @Risk add-on package. Results of 302 surveys with data collected in Israel were as follows: 92.3% of people consumed beef, mostly at home, and 98.2% preferred levels of cooking that ensured STEC removal from the surface of beef cuts. The preferred degree of ground beef doneness was "well-done" (48.2%). Cooking preference ranged from red to "medium-well done" (51.8%). Median HUS probability from Argentinean beef cut and ground beef consumption in children under 14 years old was <10−15 and 8.57x10-10, respectively. The expected average annual number of HUS cases and deaths due to beef cut and ground beef consumption was zero. Risk of infection and HUS probability correlated with salting effect on E. coli count, processing raw beef before vegetables, ways of storage and refrigeration temperature at home, joint consumption of salad and beef cuts, degree of beef doneness and cutting board washing with detergent after each use with beef and vegetables. The STEC-HUS risk in Israel from consumption of bovine beef produced in Argentina was negligible. The current QMRA results were similar to those of previous beef cut consumption QMRA in Argentina and lower than any of the QMRA performed worldwide in other STEC-HUS linked to ground beef consumption. This study confirms the importance of QMRA to estimate and manage the risk of STEC-HUS from beef consumption. The impact variables identified in the sensitivity analysis allowed us to optimize resources and time management, to focus on accurate actions and to avoid taking measures that would not have an impact on the risk of STEC-HUS. [ABSTRACT FROM AUTHOR]

Background Shiga toxin-producing Escherichia coli (STEC) are enteric pathogens that cause hemolytic-uremic syndrome (HUS). Ruminants, especially cattle, are their main reservoir. This study describes the seroepidemiology of STEC in rural and urban populations in Argentina, a country with a high HUS incidence. Methods A cross-sectional study was performed in patients without gastrointestinal symptoms. IgG antibodies against Stx2 were detected by western blotting. Results Anti-Stx2 antibodies were detected in 14.56% of serum samples, more frequently in rural (19.38%) than urban residents (12%). Seropositivity was associated with lower socioeconomic status (SES). Among the other variables considered, thawing homemade hamburgers before cooking them, and the lack of knowledge about HUS were also associated with seropositivity. A multivariate logistic regression analysis performed with the variables that were statistically significant showed that only the SES index remained significant. As SES was measured based on several variables, we further analyzed each one of them and found that the lack of a high education level was statistically associated with seropositivity. Conclusions The present findings have implications for STEC prevention efforts, highlighting the importance of considering SES and risks factors linked to different SES levels when targeting consumer-level public health interventions. [ABSTRACT FROM AUTHOR]

Investigated word reading abilities in Argentine Spanish-speaking children learning to read in Spanish. The study compared the performance of skilled and less skilled readers in phonological recoding, knowledge of grapheme-phoneme correspondences, and phonemic awareness. Findings indicate that the children rely on phonological recoding strategies. (59 references) (Author/CK)

The objective of this study was to develop a quantitative microbial risk assessment (QMRA) model to evaluate potential risk mitigation strategies to reduce the probability of acquiring hemolytic uremic syndrome (HUS) associated with beef consumption in Argentina. Five scenarios were simulated to evaluate the effect of interventions on the probability of acquiring HUS from Shiga toxin-producing Escherichia coli (STEC)-contaminated ground beef and commercial hamburger consumption. These control strategies were chosen based on previous results of the sensitivity analysis of a baseline QMRA model. The application of improvement actions in abattoirs not applying Hazard Analysis and Critical Control Points (HACCP) for STEC would result 7.6 times lower in the probability that consumers acquired HUS from ground beef consumption, while the implementation of improvements in butcher shops would lead to a smaller reduction. In abattoirs applying HACCP for STEC, the risk of acquiring HUS from commercial hamburger consumption was significantly reduced. Treatment with 2% lactic acid, hot water and irradiation reduced 4.5, 3.5 and 93.1 times the risk of HUS, respectively. The most efficient interventions, in terms of case reduction, being those that are applied in the initial stages of the meat chain. [ABSTRACT FROM AUTHOR]

Poultry production is linked to veterinary drug use to treat diseases. Few ectoparasitic compounds are approved for poultry. Fipronil is a pesticide widely used in agriculture. It is also a drug authorized to control ectoparasites in small animals and, in some countries, in cattle. There has been evidence of fipronil extra‐label use in laying hens, mainly to control the red mite Dermanyssus gallinae. Fipronil's popularity is due to its high toxicity to invertebrates. It could be metabolized to more toxic metabolites that potentially damage human health. In the present study, we carry out a quantitative exposure assessment and risk characterization for fipronil residues in laying hen eggs for local consumption in five cities of Buenos Aires province in Argentina, namely, Azul, Balcarce, Juarez, Chaves, and Tandil. Consumption surveys and egg sampling were conducted for three summer periods. Eggs were analyzed by UFLC‐MS‐MS. Fipronil prevalence, residue concentrations, residue stability to cooking methods, egg consumption, among the most important variables were modeled. The results indicated that 20.7% of samples contained fipronil residues. The highest residue was fipronil sulfone metabolite. Fipronil concentrations quantified ranged between 10 and 2510 ppb (median value = 150 ppb). When eggs were cooked, fipronil residues were stable. The exposure assessment and risk characterization revealed that the highest probability of consuming eggs with fipronil residues above the admissible limits was for young adults (20.8%), followed by babies (16.9%), young children (16.4%), children (13.4%), teenagers (10.3%), older adults (9.41%), and adults (8.65%). These results suggest an unacceptable risk associated with egg consumption with fipronil residues for all age groups. Practical Application: Fipronil is widely used as an extra‐label way on laying hens since its use is prohibited in poultry production both in Argentina and in most countries. This molecule has been classified as Class II, a moderately hazardous pesticide because it could damage various human organs. Fipronil residues in eggs could be one of the exposure pathways for consumers. Monitoring residual levels and carrying out the health risk assessment in eggs are thus in an urge. [ABSTRACT FROM AUTHOR]

Copyright of Revista Veterinaria is the property of Universidad Nacional del Nordeste and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Varroa destructor is one of the most important sanitary threats for the beekeeping industry and so far disease control is based mainly on chemical treatment. However, a long-term solution may arise from studying natural surviving colonies of Apis mellifera. We compared the Varroa infestation rate in six commercial colonies that received annual treatment against mites and six non-treated colonies that survived in absence of any treatment for the last 6 years. In addition, we evaluated two potential mechanisms that might be involved in colony survival: hygienic (HYG) and Varroa-sensitive hygiene behavior (VSH) by means of pin-killed and mite artificial infestation, respectively. HYG and VSH were negatively correlated with mite infestation independently of the colony group (treated or non-treated). Furthermore, colonies expressing high levels of pupae removal (≥ 80%) showed higher %HYG and lower mite infestation compared to colonies showing low pupae removal (< 80%). The analysis of reproductive status of mites from the non-removed infested cells evidenced that more infertile mites are found in colonies with more than 80% of pupae removal. To study non-treated colonies that survive for several years, it is a suitable approach for identifying the underlying mechanisms related to Varroa-resistance. [ABSTRACT FROM AUTHOR]

Myzus persicae (Sulzer) is a highly polyphagous aphid species that attacks several economically important crop plants. Here, trophic webs involving M. persicae, its host plants and its parasitoids were described and quantified in wheat, oat and alfalfa agroecosystems from central Argentina, with special emphasis on the sub‐habitats where interactions occur: crops and adjacent field margins. Three fields cultivated with each crop species and their margins were sampled during three years; aphid abundance and mummification percentage were compared among crop plants and the diverse natural vegetation in the borders. Interactions were described using a quantitative food web approach, and abundance and mummification percentage e data were analysed using a generalized linear model. Four plant species present in the borders (Capsella bursa‐pastori, Rapistrum sp., Melilotus sp. and Trifolium repens) hosted M. persicae and its parasitoids. The alfalfa agroecosystem produced a significantly higher number of aphids than oat and wheat; however, in all cases, crops and borders sustained similar aphid abundance. A total of six Aphidiinae species attacked M. persicae, with no significant differences in the richness of parasitoid species between the borders and the crops, but with significant differences in parasitoid abundance, being higher in the crops. Mummification percentage were higher in crops than in the borders, with Lysiphlebus testaceipes, Aphidius colemani and A. ervi being the most abundant species. Almost 70% of M. persicae individuals were collected from fields borders, which highlights the importance of including these sites in studies of trophic interactions in crop fields. [ABSTRACT FROM AUTHOR]

A longitudinal study was carried out in order to evaluate Nosema spp. spore counts in two key moments of the year (late autumn and spring) in honeybee colonies from five eco-regions of Argentina. Three hundred and sixty colonies were randomly selected and the infestation level of Nosema spp. and Varroa destructor was assessed in autumn and spring of 2015. In addition, a questionnaire concerning all management practices applied in the colonies was answered by the beekeepers. Generalized linear mixed effect models were performed to determine the relationship between risk factors associated with Nosema spp. spore counts in each eco-region. Data were scanned to identify colonies cluster with a higher probability of achieving high values of Nosema spp. abundance for each sampling period. Spatial distribution of colonies with a higher risk of achieving high Nosema spp. abundance seems to be explained by geographical conditions associated to climatic conditions and some management practices implemented in each eco-region. [ABSTRACT FROM AUTHOR]

We developed a quantitative microbiological risk assessment (QMRA) of haemolytic uremic syndrome (HUS) associated with Shiga toxin-producing Escherichia coli (STEC)-contaminated beef (intact beef cuts, ground beef and commercial hamburgers) in children under 15 years of age from Argentina. The QMRA was used to characterize STEC prevalence and concentration levels in each product through the Argentinean beef supply chain, including cattle primary production, cattle transport, processing and storage in the abattoir, retail and home preparation, and consumption. Median HUS probability from beef cut, ground beef and commercial hamburger consumption was <10−15, 5.4x10-8 and 3.5x10-8, respectively. The expected average annual number of HUS cases was 0, 28 and 4, respectively. Risk of infection and HUS probability were sensitive to the type of abattoir, the application or not of Hazard Analysis and Critical Control Points (HACCP) for STEC (HACCP-STEC), stx prevalence in carcasses and trimmings, storage conditions from the abattoir to retailers and home, the joint consumption of salads and beef products, and cooking preference. The QMRA results showed that the probability of HUS was higher if beef cuts (1.7x) and ground beef (1.2x) were from carcasses provided by abattoirs not applying HACCP-STEC. Thus, the use of a single sanitary standard that included the application of HACCP-STEC in all Argentinean abattoirs would greatly reduce HUS incidence. The average number of annual HUS cases estimated by the QMRA (n = 32) would explain about 10.0% of cases in children under 15 years per year in Argentina. Since other routes of contamination can be involved, including those not related to food, further research on the beef production chain, other food chains, person-to-person transmission and outbreak studies should be conducted to reduce the impact of HUS on the child population of Argentina. [ABSTRACT FROM AUTHOR]

Copyright of Revista Veterinaria is the property of Universidad Nacional del Nordeste and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aims of the research reported here were to identify potential risk factors associated with the presence of Staphylococcus aureus intramammary infection (IMI) in pre partum dairy heifers on 17 dairy farms from three provinces of Argentina and to characterize, at molecular level, isolates from those heifers and lactating cows from two selected herds. A total of 1474 heifers and 4878 lactating cows were studied. The prevalence of Staphylococcus aureus IMI in the heifers, heifers at quarter level and lactating cow mammary quarters was 14.41, 4.82, and 14.65%, respectively. Univariate analysis showed the key variables associated with S. aureus IMI presence in the heifers were: S. aureus IMI prevalence in cows of the lactating herd, the time calves stayed with their dam after birth, the calf rearing system, the place of rearing (own farm or other dairy farm) and fly control on the farm. None of the variables included in the multivariable analysis was associated with the presence of S. aureus IMI in the pre partum heifers, probably due to low variability among management practices used by the farms for rearing the heifer calves. At the molecular level, S. aureus isolates were grouped into three main PFGE clusters and several genotypes within the clusters. Isolates from mammary secretion of pre partum heifers and milk of lactating cows comprised different PFGE clusters in both herds, although two exceptions occurred. The absence of gene fnbpB , which codifies for a virulence factor protein involved in cell invasion by S. aureus , was significantly more frequent in pre partum heifer secretion isolates than in isolates from lactating cow milk. These results suggest that, under these management conditions, isolates from mammary secretions of pre partum heifers do not originate from the milk of lactating cows, but rather other sources to which the heifer is exposed. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the most important and widely cultivated crops in Argentina. Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a common maize pest capable of causing significant yield losses and is most destructive in late-planted maize in subtropical regions, going through five to six generations per growing season. The Bacillus thuringiensis (Bt) trait Herculex I Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred (HX I, event DAS-Ø15Ø7-1), expressing Cry1F protein, was launched in the 2005–2006 season in Argentina and was widely adopted because of the high level of efficacy against S. frugiperda , as well as other pests such as Diatraea saccharalis (J.C. Fabricius). However, increased late-season plantings, limited adoption of refuge, and properties of S. frugiperda biology (high number of generations and migratory behavior) have led to high S. frugiperda exposure to Cry1F and resistance selection pressure. Field efficacy monitoring has been conducted throughout the main maize production areas in Argentina from 2009 to 2016. Laboratory monitoring has been conducted throughout the same areas from 2010 to 2015. Here, we describe changes in field efficacy of HX I and the results of laboratory-based susceptibility monitoring conducted using purified Cry1F protein. Increases in larval survival and crop damage were evident throughout the 2012–2016 period and spanned the majority of maize production areas in Argentina. Over the same period, random larval collections showed increasing survivorship on diet containing purified Cry1F protein. These field and laboratory studies confirmed that resistance to Cry1F has developed and is now widely distributed in S. frugiperda populations in Argentina. [ABSTRACT FROM AUTHOR]

Copyright of Revista Veterinaria is the property of Universidad Nacional del Nordeste and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Transgenic maize (Zea mays L.) event TC1507 (Herculex® I insect protection), expressing Cry1F 휹-endotoxin derived from Bacillus thuringiensis var. aizawai, was commercialized in 2003 in the Americas. Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) susceptibility to Cry1F was monitored annually across several regions in Argentina using diagnostic concentration bioassays. Reduced performance of TC1507 maize against S. frugiperda was reported in 2013. A resistant population was established in the laboratory and the dominance of Cry1F resistance was characterized. RESULTS: During 2012–2015, high-survivorship of several populations was observed in the resistance monitoring program. Reciprocal crosses of a Cry1F-resistant population with a Cry1F-susceptible population were evaluated to calculate effective dominance (DML) based on mortality levels observed at 100 훍g/ml Cry1F. Two additional dominance levels (DLC and DEC) were calculated using lethal (LC50) or effective concentration (EC50) derived from concentration–response bioassays. Estimates indicated that Cry1F resistance in S. frugiperda in Argentina was either highly recessive (DML =0.005) or incompletely recessive (DLC <0.26 and DEC <0.19). CONCLUSION: This study is the first documented confirmation and characterization of S. frugiperda Cry1F field-evolved resistance in Argentina. The resistance to Cry1F in S. frugiperda populations collected in Argentina, is autosomal and incompletely recessive similar to the resistance reported in Brazil. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The aim of this work was to test the efficacy of strategic control methods of Rhipicephalus microplus infestation on beef cattle grazed in Panicum maximum grasses in northwestern Argentina. Also, an analysis to discern how the R. microplus population was distributed amongst cattle was also performed to determine if partial selective treatment or cull the small proportion of more heavily infested animals are feasible options to control this tick. The strategic scheme of treatments was designed to act on the small 1st generation of R . microplus in early spring and prevent in that way the appearance of the annual peak of abundance of R. microplus in summer and autumn. Animals of the group 1 were treated with ivermectin 3.15% on day 0 (25th September 2015), with fluazuron on day 32 (27th October 2015) and with fipronil on day 75 (9th December 2015). Animals of group 2 formed the control group. The overall effect of the treatments was positively significant. The number of ticks observed on the control group was significantly higher than the number of ticks observed on the treated group in all post-treatment counts (P < 0.01), with the only exception of the count of March. The distribution of parasites among cattle in all counts was adjusted to the negative binomial distribution, but a temporal variation in the tick aggregation levels associated to changes in tick abundance was found. The higher the abundance of R . microplus , the lower the aggregation. It was found that the steers (15.8% of the total number of animals evaluated) belonging to the high infestation group accounted for 23.0% of the total ticks. The strategic control method evaluated during this study provides a remarkable overall effect against R. microplus because it significantly reduces the tick infestation on cattle with only three applications of acaricides in one-year period. The analyses of tick distribution amongst cattle suggest that partial selective treatment and culling do not represent feasible methods to control R . microplus infestation on cattle. [ABSTRACT FROM AUTHOR]

A chronic dietary risk assessment for pesticide residues was conducted for four age groups of the Argentinian population following the procedure recommended by the WHO. The National Theoretical Maximum Daily Intake (NTMDI) for 308 pesticides was calculated for the first time, using the Maximum Residue Limits (MRLs) from several Argentinean regulations and food consumption data from a comprehensive National Nutrition and Health Survey. The risk was estimated by comparing the TMDI with the Acceptable Daily Intakes (ADI) identified by various sources. Furthermore, for each of the compounds with a TMDI >65% of the ADI, a probabilistic analysis was conducted to quantify the probability of exceeding the ADI. In this study 27, 22, 10, and 6 active ingredients (a.i.) were estimated to exceed the 100% of the ADI for the different population groups: 6-23 month-old children, 2-5 year-old children, pregnant women, and 10-49 year-old women, respectively. Some of these ADI-exceeding compounds (carbofuran, diazinon, dichlorvos, dimethoate, oxydemeton-methyl and methyl bromide) were found in all four of these groups. Milk, apples, potatoes, and tomatoes were the foods that contributed most to the intake of these pesticides. The study is of primary importance for the improvement of risk assessment, regulations, and monitoring activities. [ABSTRACT FROM AUTHOR]

In Argentina, there are three known species of genus Trichinella; however, Trichinella spiralis is most commonly associated with domestic pigs and it is recognized as the main cause of human trichinellosis by the consumption of products made with raw or insufficiently cooked pork meat. In some areas of Argentina, this disease is endemic and it is thus necessary to develop a more effective programme of prevention and control. Here, we developed a quantitative risk assessment of human trichinellosis following pork meat sausage consumption, which may be used to identify the stages with greater impact on the probability of acquiring the disease. The quantitative model was designed to describe the conditions in which the meat is produced, processed, transported, stored, sold and consumed in Argentina. The model predicted a risk of human trichinellosis of 4.88 × 10−6 and an estimated annual number of trichinellosis cases of 109. The risk of human trichinellosis was sensitive to the number of Trichinella larvae that effectively survived the storage period ( r = 0.89), the average probability of infection ( PPinf) ( r = 0.44) and the storage time (Storage) ( r = 0.08). This model allowed assessing the impact of different factors influencing the risk of acquiring trichinellosis. The model may thus help to select possible strategies to reduce the risk in the chain of by-products of pork production. [ABSTRACT FROM AUTHOR]

To describe the epidemiology of cystic ovarian disease (COD), to find possible risk factors associated with the incidence of cysts and to analyse the impact of COD on the reproductive performance of dairy cows, databases from 22 dairy herds from the main dairy region in Argentina were retrospectively evaluated throughout a 3-year period (2009-2011). A total of 248 COD cases over 9156 parturitions were recorded, resulting in a cumulative incidence rate of 2.7%. Cystic ovarian disease incidence density was lower during the first 100 days post-partum (DPP) than during later stages of lactation. Seasonality had a significant influence on the disease presentation with higher incidence rates during winter and spring. Cows with a previous diagnosis of clinical mastitis showed 2.72 times more chances of developing ovarian cysts. Cystic cows had longer calving to first service and calving to conception intervals and lower conception rate than controls. [ABSTRACT FROM AUTHOR]

Objective To estimate the frequency of zoonoses in rural veterinarians and to search for risk factors. Design Cross-sectional study based on an anonymously answered structured questionnaire. Setting The interviewees participated in mandatory continuing education classes scheduled throughout the province by the College of Veterinary Surgeons. Participants Overall, 741 professionals were surveyed, and 75.8% ( n = 562) of them completed the structured questionnaire. Main outcome measures Cumulative incidence ( CIR) and incidence density ( IDR) rates, standardised rates, χ2, Student's t-test, Pearson's correlation coefficient and logistic regression. Results The CIR for all zoonoses was 34.1% (brucellosis, 29.1%; toxoplasmosis, 2.1%; leptospirosis, 0.6%; tuberculosis, 0.6%; anthrax, 0.6%; ringworm, 0.4%; other, 0.6%). The IDR for the period 1964-2008 was estimated to be 20.7% (19.5% for brucellosis). The brucellosis IDR decreased between 1964 and 2008 and was higher during early post-graduation. The risk of brucellosis was associated with the number of years of practice and the geographical area. Sixty-nine respondents had at least one day of absence from work (24.0 ± 27.8 days). Conclusions A high frequency of zoonoses was reported by veterinarians with a large animal practice. Although the rate of zoonoses may be decreasing, further studies are needed to confirm this finding. A joint effort of all institutions is needed to prevent zoonoses among private practitioners. [ABSTRACT FROM AUTHOR]

Abstract: Here, we developed a quantitative risk assessment for thermophilic Campylobacter spp. related to the consumption of salad prepared alongside broiler meat. The assessment considered initial contamination levels, cross-contamination and decontamination events during the broiler slaughter process and distribution, and storage and consumption patterns in Argentina and other Latin American countries. The model predicted an infection risk of 3.32×10−4 per serving. This estimation was variable according to the dose–response model used. Considering the number of chickens slaughtered annually in Argentina, the estimated number of people who could suffer campylobacteriosis related to poultry meat consumption was, on average, 484,304. The risk of human campylobacteriosis was most sensitive to the probability of infection from a Campylobacter (r =0.72), the number of Campylobacter spp. per serving (r =0.40), the frequency of washing the cutting board (r =−0.31), the preparation of raw poultry before salad using the same cutting board (r =0.14), and the frequency of hand washing (r =−0.14). The most sensitive stages of the process identified through the risk assessment can be used as a basis for measures of risk management. Public campaigns on hygiene habits during food preparation at home should focus on the importance of washing the cutting board before preparing raw and ready-to-eat foods and of washing the hands during food preparation. [Copyright &y& Elsevier]

Abstract: A stochastic simulation model was developed to carry out the first quantitative risk exposure assessment of the mycotoxin level in cow’s milk produced in Argentina. The prevalence and concentration of aflatoxin M1 (AFM1), deoxynivalenol (DON) and zearalenone (ZEA) were modeled at various stages through milk processes complying with Argentinean practices. Concentration of AFM1 (0.059ppb), DON (0.338ppb) and ZEA (0.125ppb) in dairy milk were estimated. The proportion of feed samples that exceeded the maximum level accepted by European regulations for AFB1, DON and ZEA were estimated at 25.07%, 0.0% and 8.9%, respectively. The percentage of milk samples that exceeded the maximum level accepted for AFB1 by the MERCOSUR (0.5ppb) and the European Union regulations (0.05ppb) were 0.81 and 32.65, respectively. The probability distribution of AFM1 concentration in milk was affected by the carry-over rate equations applied in the model. Mycotoxin levels in corn silage and concentrated feeds were the factors most correlated with mycotoxin concentrations in milk. Therefore, agricultural practices, crop management and feed production require prompt attention regarding mycotoxin issues. [Copyright &y& Elsevier]

Objectives. Quantify contamination by verotoxin-producing Escherichia coli associated with hemolytic uremic syndrome (VTEC-HUS) in cattle carcasses and generate estimates of exposure in three likely scenarios. Methods. A model was constructed of the frequency and magnitude of VTEC-HUS contamination from primary production to the removal of the carcasses from cold storage, based on the published scientific information, epidemiological data, and information from local experts. The probability distributions that best described each step in the process and scenarios were input to the @Risk® program with multiple simulations using Monte Carlo analysis. Pearson's correlation test was used for the sensitivity analysis. Results. The estimated frequency of carcasses with VTEC-HUS was 0.37 (95% CI: 0.26 to 0.58) and the final load of VTEC-HUS was 0.47 log CFU/carcass (95% CI: -2.46 to 3.62). The most closely related variables were the fattening system (r = -0.681) and the theoretical concentration of VTEC-HUS on the cattle's skin (r = 0.702). Vaccinating the animals reduced the frequency of VTEC-HUS in the carcasses by 54.1%, although there were no significant changes in the final VTEC-HUS load. Washing the carcasses reduced the final load by 0.42 log CFU/carcass compared with the baseline model, without any change in the frequency. A 50%-60% increase in the percentage of animals fattened in pens would increase the frequency of carcasses contaminated with VTEC-HUS by 15%-23%. Conclusions. Vaccinating the animals was the most effective scenario for reducing introduction of the bacteria in the beef production chain. Intensifying livestock production will increase the public health risk due to greater exposure to VTEC-HUS. [ABSTRACT FROM AUTHOR]

Abstract: A stochastic simulation model was used to assess the effects of measures implemented in the agri-food-chain to reduce the contamination of ground beef with verotoxigenic Escherichia coli (VTEC). A published risk assessment model developed in Argentina was used as baseline scenario. Control measures assessed were based on either a reduction in herd prevalence of infection due to vaccination, reduction in opportunity for cross-contamination in the slaughterhouses by the introduction of an on-line hide-wash cabinet, and control of storage temperature in slaughterhouses, retail and home. Additionally, the increase of feedlot production was modelled. Simulations suggested that the greatest potential impact was associated with hide-wash cabinet and vaccination, measures aimed to reduce the VTEC prevalence and concentration in the cattle hides at the beginning of the food-chain. Control of storage temperature was not effective if the carcasses cross-contamination with the pathogen was not prevented or reduced. An increase production (fattening) of cattle in feedlots may raise the risk of VTEC infection and its sequelae. This information can be used as a basis for measures of risk management. [Copyright &y& Elsevier]

Abstract: A quantitative risk assessment was developed for verocytotoxigenic Escherichia coli (E. coli VTEC) following hamburger consumption. The assessment considers initial contamination levels, cross-contamination and decontamination events during the cattle slaughter process and the distribution, storage and consumption patterns in Argentina and in similar countries in Latin-American. The model predicted an infection risk of 8.12×10−7, a probability of Hemolytic Uremic Syndrome (HUS) of 4.6×10−8 and a probability of mortality of 5.9×10−9 per meal for adults. For children, the estimates per meal were 3.23×10−7, 1.8×10−8 and 6.31×10−10 for infection, HUS and mortality, respectively. The risk of infection and HUS, were sensitive to the type of storage at home (r =−0.416), slaughterhouse storage temperature (r =0.240) and bacterial concentration in the cattle hide (r =0.239). There was an association between home preparation of hamburgers (r =−0.116) and the risk of illness, although this was a result of the type of storage at retail (r =−0.110) and at home and not their intrinsic characteristics. The most sensitive stages of the process were identified through the risk assessment and these can be used as a basis for measures of risk management. [Copyright &y& Elsevier]

Introduction: Leptospirosis is a neglected zoonotic disease, affecting mainly poor and vulnerable populations. Methodology: A cross sectional-study was carried out in 557 subjects from Olavarría county (Argentina) to estimate the seroprevalence of leptospirosis and the factors associated with seropositivity. A survey was carried out to obtain clinical and epidemiological data. Serum was tested for anti-leptospiral antibodies by Microscopic Agglutination Test (MAT). Chi-square or Fisher Exact tests were used to assess association between the MAT results and the exploratory variables. For the variables statistically associated, odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated. Individuals from Olavarría city were georeferenced to describe the spatial distribution and to detect clusters of seropositivity for leptospiral antibodies. Results: The overall prevalence of leptospirosis infection was 7.00%, higher in rural (19.66%) than in urban populations (3.64%) (p < 0.001). Sejroe was the most predominant serogroup in rural communities while Icterohaemorrhagiae was the most prevalent in urban populations. The factors associated with Leptospira infection were the presence of rodents inside households (OR = 3.9) in rural populations, while contact with cats (OR = 4.97) and male gender (OR = 7.75) represented higher risk of infection for the urban ones. Cases with positive serology have been found near Tapalqué stream or in the peripheral areas of Olavarría city. Conclusions: The results from data obtained during the study period were similar to other reports and demonstrate the importance of continuous epidemiological surveillance system and specific community educational campaigns to prevent the leptospirosis infection in Olavarría county and other communities with similar characteristics especially in rural areas. [ABSTRACT FROM AUTHOR]

Heat stress has been widely studied in relation to its effects on the production and reproduction of dairy cattle. However, the long-term effects of heat stress during intrauterine development on adult cows have been scarcely considered. Thus, the aim of this study was to evaluate possible changes in the reproductive performance of Holstein cows gestated under different values of the Temperature-Humidity Index (THI) during their intrauterine development. Data collected from a database of reproductive and productive records of 10,790 Holstein cows from the central region of Argentina and the THI data from the agrometeorological station of the Instituto Nacional de Tecnología Agropecuaria (INTA) EEA Rafaela, Santa Fe, Argentina, were used. The gestation of the cows evaluated was divided into trimesters, in which the highest THI cycles (sum of three or more consecutive days of exposure to a THI ≥72 during each trimester) and number of days with a THI ≥ 72 were calculated. The calving-to-conception and calving-to-first-service intervals of the cows evaluated were considered as reproductive variables associated with their first lactation. Generalized Linear Mixed Models were used, considering the cow's dairy farm as a random factor within the model. The exposure of the animals to environments with a THI ≥72 during the first trimester of gestation had a negative impact on the reproductive efficiency parameters analyzed. The results obtained indicate that the exposure of pregnant females to high THI values has a long-term impact on their daughters, which may contribute to a decrease in their reproductive performance, possibly through inherited epigenetic characteristics that remain in later generations through fetal programming. • Exposure to high THI values during the first third of gestation has a negative impact on cattle progeny. • Heat stress during gestation negatively affects the CCI and CFSI of the resultant offspring. • The first trimester of gestation is critical for reproductive development of cattle. [ABSTRACT FROM AUTHOR]

Abstract The presence of Varroa destructor in colonies of Apis mellifera is explained by the interaction among a number of factors including beekeeping practices and surrounding environment features. The aim of this study was to evaluate the relative impact of environment geographical region and beekeeping management on Varroa infestation levels throughout a year. A monitoring study was carried out during 2015 in north-central regions from Argentina, consisting of three sampling dates: 1) autumn survey before autumn acaricide treatment; 2) autumn survey after autumn acaricide treatment and 3) spring survey. During these visits, we collected samples for Varroa mites and Nosema sp. presence assessment and information concerning the apiary management practices during each period. Both regional location and beekeeping practices impact on V. destructor infestation level during the course of the year, but relative importance depend partially on the time of year when this was observed. Varroa infestation level is driven simultaneously by a wide-range of environmental factors (regional effect) and honeybee population dynamics. Additionally, colony life histories are also strongly affected by the management practices employed by beekeepers, especially regarding the Varroa mites control and the supplementary feeding. Complexity involving multiple factors interaction in socio-ecological systems like beekeeping is discussed. [ABSTRACT FROM AUTHOR]

Quantitative risk assessment was used to estimate the risk of introducing foot-and-mouth disease (FMD) through bone-in beef from Argentina (FMD-free with vaccination status) into other FMD-free countries. A stochastic model was built to characterize all the steps from primary production to bone-in beef export and introduction into an FMD-free country. The probability that bone-in beef from at least one animal infected with the FMD virus (FMDV) was exported during a year was 5.27 × 10−3 (95% CI <10−10 – 5.19 x 10–2) or in other words one case in 190 years. The risk of FMDV introduction was sensitive to the probability of an outbreak occurring in Argentina (r [Spearman´s rank correlation] = 0.99) and the number of herds affected during an outbreak (r = 0.10). Additionally, the probability that susceptible animals in the importing country came into contact with infective material (bones) and generated an outbreak was 6.16 × 10−4 (95% CI <10−10 – 6.20 ×10−3) or one FMD outbreak every 1623 years on average. Based on the quantitative risk assessment results, the probability of FMDV introduction into a FMD-free country where vaccination is not practiced from a FMD-free country where vaccination is practiced associated with bone-in beef trade from Argentina was negligible. The risk of an FMD outbreak caused by the potential introduction of the FMDV was associated with the existing conditions in the country. Thus, maintaining the FMD-free status with or without vaccination would not be relevant. • QRA was used to estimate the risk of introducing FMD through bone-in beef from Argentina. • The probability of FMD introduction from a country FMD-free with vaccination status was negligible. • FMD outbreak caused by the re-introduction of the FMD virus was associated with the existing conditions in the country. • maintaining the FMD-free status with or without vaccination would not be relevant. [ABSTRACT FROM AUTHOR]

A total of 361 colonies from 59 apiaries located in two temperate and three subtropical eco-regions were examined during the post-harvest period to determine distribution and prevalence of Nosema spp. Apiaries from subtropical eco-regions showed a lower spore count than those from temperate eco-regions. Pure N. ceranae and co-infection were detected in apiaries from all regions. In contrast, pure N. apis infection was exclusively observed in the subtropical study region. The predominant detection of N. apis in a subtropical region joining a southern temperate region where mainly co-infected apiaries were identified is in contrast to previous reports. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the antimicrobial resistance in thermotolerant Campylobacter spp. isolated from different stages of the poultry meat supply chain in Argentina. Six poultry meat chains were studied from the reproductive farm to the chicken at the retail. Chickens sampled along each food chain were from the same batch. Samples collected were: a) cloacal samples from hens and chickens on the farm, b) chicken carcasses from the slaughterhouse and retail market. Samples obtained were examined for Campylobacter spp. Antimicrobial resistance was evaluated using the disk diffusion method. Almost all isolates were resistant to nalidixic acid (91.2%) and ciprofloxacin (88.2%). A large proportion of thermotolerant Campylobacter isolated from hens and broilers <1 wk showed resistance to erythromycin in comparison with the rest of the stages of the poultry meat supply chain ( P = 0.031). Campylobacter isolated from broilers (both <1 wk and >5 wk) and carcasses at slaughterhouse and at retail showed a proportion of resistance to ciprofloxacin and enrofloxacin higher than isolates from hens ( P = 0.015 and P = 0.031, respectively). One strain was resistant to all the antibiotics analyzed, and 46.1% of the isolates were resistant to three or more drug classes. Almost 50% of the isolates were resistant to all quinolones tested (ciprofloxacin, nalidixic acid, and enrofloxacin), and 13.2% were resistant to all quinolones and erythromycin. Campylobacter strains isolated from carcasses at retail showed higher resistance to all quinolones than strains isolated from hens ( P = 0.016). These results reflect an alarming situation with potential serious consequences to the public health. [ABSTRACT FROM AUTHOR]

Abstract: Varroa destructor is considered one of the major threats for worldwide apiculture. Damage caused by varroa mite includes body weight loss, malformation and weakening of the bees. It was also suggested as the main cause associated with colony winter mortality and as an important vector for several honey bee viruses. Little is known about multiple factors and their interaction affecting V. destructor prevalence in apiaries from South America. The aim of this study was to identify risk factors associated with V. destructor prevalence in east-central Argentina. Parasitic mite infestation level and colony strength measures were evaluated in 63 apiaries distributed in 4 different regions in east-central Argentina in a cross sectional study. Data regarding management practices in each apiary were collected by means of a questionnaire. A mixed-effects logistic regression model was constructed to associate management variables with the risk of achieving mite infestation higher than 3%. Colonies owned by beekeepers who indicated that they did not monitor colonies after mite treatment (OR=2.305; 95% CI: 0.944–5.629) nor disinfect hives woodenware material (OR=2.722; 95% CI: 1.380–5.565) were associated with an increased risk of presenting high intensity infestation with V. destructor (>3%). On the other hand, beekeepers who reported replacing more than 50% of the queens in their operation (OR=0.305; 95% CI: 0.107–0.872), feeding colonies protein substitute containing natural pollen (OR=0.348; 95% CI: 0.129–0.941) and feeding colonies High Fructose Corn Syrup (HFCS) (OR=0.108; 95% CI: 0.032–0.364), had colonies that were less likely to have V. destructor infestations above 3%, than beekeepers who did not report using these management practices. Further research should be conducted considering that certain management practices were associated to mite infestation level in order to improve the sanitary condition in the colonies. Epidemiological studies provide key information to design surveillance programs against one the major threat to worldwide beekeeping. [Copyright &y& Elsevier]

Objective. To characterize recorded trichinosis cases and outbreaks in Santa Fe Province, Argentina, from 1998 to 2009 from epidemiological, clinical, and laboratory viewpoints. Methods. An analysis was conducted of 1 519 epidemiological records of persons who had signs and symptoms compatible with trichinosis in Santa Fe Province in the period 1998-2009. A descriptive statistical analysis of information in epidemiological records and of clinical and laboratory results, as well as a bifactorial analysis of possible associations with epidemiological and environmental factors were also carried out. Results. Trichinosis symptoms were found in 1 276 cases; 372 met the clinical case definition and 224 samples were positive by indirect immunofluorescence, independent of their clinical case classification. There were 27 outbreaks that involved 1 157 cases identified in eight departments, with greater frequency in the province's center and south. Annual distribution of epidemiologically associated cases was heterogeneous, with greater frequency in the period 2000-2003 and in the months of August to October. Probability of becoming sick was greater with consumption of products from informal sources (OR = 3.69; P = 0.014) and in rural areas (OR = 1.799; P = 0.011). Disease incubation period (median) was 12 days. The risk of becoming sick was 2.06 times greater in persons who ate meat or ate pork by-products than in those who did not. Conclusions. The greatest number of outbreaks occurred in departments that were more populous and where pork production was greater. Specific actions should be designed for prevention and control of the disease in those departments. Epidemiological risk analysis should be considered in evaluating, managing, and communicating trichinosis health risks. [ABSTRACT FROM AUTHOR]

The risk of acquiring listeriosis from consuming fermented sausages and dry-cured pork shoulder (capicola/bondiola) in Argentina was estimated using quantitative microbiological risk assessment. The model included data about initial prevalence and contamination level of Listeria monocytogenes , product formulation with or without a starter culture (lactic acid bacteria [LAB]), time and temperature during distribution and storage prior to consumption, and consumption patterns. The probability of listeriosis from fermented sausage consumption in at-risk populations was estimated with average values of <10−11 per portion consumed. The main factor associated with such probability was the use of LAB in fermented sausage production, which reduced the risk by at least three orders of magnitude. Meat mass pH during fermentation and water activity (a w) at the end of ripening were the factors having the greatest impact on the probability of listeriosis. Thus, LAB added during production, pH values < 5.1 at the end of fermentation and a w <0.93 during ripening indicated that the environment was not appropriate for L. monocytogenes development, suggesting that fermented sausages had an adequate safety level. On the other hand, the risk of listeriosis from dry-cured pork shoulder consumption was negligible, even in the most susceptible populations. Both a w level and the strict control of process temperature were the main risk factors for acquiring listeriosis. The level of protection given by the current Argentine microbiological criterion for fermented sausages and dry-cured pork shoulder (absence of L. monocytogenes in 25 g of product) would guarantee the safety of these products similarly to the <100 cfu/g cut used in other countries. • QMRA of listeriosis from fermented sausages and dry-cured pork in Argentina. • Probability of listeriosis: <10−11 (sausage) and negligible (pork) per portion. • Lactic acid bacteria, pH and a w having the greatest impact on the probability. • Protection by Argentine criterion is similarly to used in other countries. [ABSTRACT FROM AUTHOR]

• Comprehensive evaluation, implementation of improvement actions and impact verification were performed in three abattoirs. • Detection and isolation of Salmonella spp., E. coli O157:H7 and non-O157 STEC. • Evaluation of microbiological quality and dose of residual chlorine in water. • The risk of contamination was reduced from high to moderate in all three abattoirs. • An important reduction in the presence of pathogens was observed. The slaughter process plays an important role in animal welfare, meat quality, safety and public health through the meat production chain. In this study, we performed a three-stage evaluation: I) comprehensive evaluation, II) implementation of improvement actions and III) verification of the success of the actions implemented in three abattoirs from Argentina during 2016-2018. Risk was estimated using two checklists, quantified on a 1–100 scale and classified as high (1–40), moderate (41–70) and low (71–100). In stages I and III, Salmonella spp., E. coli O157:H7 and non-O157 STEC were detected and isolated in samples from carcasses (n = 252), the environment (n = 252); head meat (n = 21) and viscera washing and chilling water (n = 105). Carcass samples were analyzed for mesophilic aerobic organisms, coliforms and E. coli enumeration. Of 201 water samples taken, 42.0–75.6 % were non-potable quality. After the implementation of improvement actions in stage II (building, processes, systems for water purification and training), the estimation of risk of contamination was reduced from high to moderate in all three abattoirs, the count of indicator microorganisms decreased in two abattoirs, and the presence of pathogens significantly decreased. Salmonella spp. was not isolated from any of the samples collected in two abattoirs. Isolation of E. coli O157:H7 decreased in carcass and was not isolated from viscera washing and chilling water. Isolation of non-O157 STEC decreased in carcass but not in environmental samples. Finally, 75.0–95.0 % of water samples were of potable quality. Although this was only the first step in the process of change and improvement of abattoirs, the assessment of the situation and the proposal of solutions to correct deviations in a joint effort with the health authorities helped to implement a work model for enhancing food safety before meat reaches consumers. [ABSTRACT FROM AUTHOR]

Shiga toxin-producing Escherichia coli (STEC) are important pathogens transmitted by food that may cause severe illness in human beings. Thus, systems for STEC detection in food should have increasingly higher sensitivity and specificity. Here we compared six commercial systems for non-O157 STEC detection in meat and vegetables and determined their sensitivity, specificity and repeatability. A total of 46 samples (meat n = 23; chard n = 23) were experimentally contaminated with strains O26:H11, O45:H-, O103:H2, O111:NM, O121:H19 and O145:NM isolated in Argentina. Strain detection was confirmed by isolation according to ISO 13136:2012. Detection of the stx and eae genes in meat samples was highly satisfactory with all commercial kits, but only five had 100% sensitivity and specificity in chard. Of four kits evaluated for serogroup detection, three had 100% sensitivity and specificity, and one had 93.7% sensitivity and 100% specificity. All kits were adequate to analyze meat but not vegetable samples, and were not therefore validated for the latter matrix. The challenge for microbiology laboratories is to identify the advantages and disadvantages of the available kits for STEC detection in food based on a clear knowledge of the particular needs of each laboratory. • Shiga toxin-producing Escherichia coli (STEC) are important pathogens transmitted by food. • Systems for STEC detection in food should have increasingly higher sensitivity and specificity. • Six commercial systems for non-O157 STEC detection in meat and vegetables were compared forsensitivity, specificity and repeatability. • Detection of the stx and eae genes was highly satisfactory with all commercial kits in meat samples, but not vegetable samples. • Advantages and disadvantages of the kits for STEC detection in food based on a clear knowledge of the particular needs of each laboratory. [ABSTRACT FROM AUTHOR]

The epidemiology of Babesia bovis was studied in terms of enzootic stability/instability and husbandry and abiotic factors influencing B. bovis transmission rate in northeastern Santiago del Estero province, Argentina. The area is of limited suitability for its only vector in Argentina, the tick Rhipicephalus microplus. The proportion of calf herds in a state of enzootic stability/instability to B. bovis was determined and husbandry practices and abiotic factors associated with variations in B. bovis transmission rates were explored using a cross-sectional observational study design. Daily probability of infection (inoculation rate, h) with B. bovis was calculated from age-specific seroprevalence via ELISAi in 58 herds of 4.5–8.5-month-old calves. Herds were considered to be in enzootic instability (EI) when h < 0.005, and therefore inferred to be at risk of babesiosis outbreaks. Husbandry practices associated with differences in B. bovis transmission were analyzed using generalized linear models. Sixty-two percent of herds were found to be in an EI situation for B. bovis. Calves raised exclusively on permanent pastures –where higher cattle density is achieved– were exposed to higher B. bovis inoculation rates (h = 0.0063, 95% CI 0.0032-0.0123) than those reared under forage combinations (h = 0.0024, 95% CI 0.0011-0.0051) (P = 0.05). In addition, calves from herds located in the area of intermediate suitability for R. microplus development were more likely to become infected with B. bovis (h = 0.0067, 95% CI 0.0037-0.0121) than those reared in the ecologically unfavorable area for the vector (h = 0.0023, 95% CI 0.0010-0.0049) (P = 0.02). Neither the frequency of treatment with acaricides nor the use of long-acting acaricides to control R. microplus influenced the inoculation rate (P = 0.99 and P = 0.26, respectively). This result indicates that current R. microplus control schemes are not effective in reducing B. bovis transmission. Enzootic instability still prevails in the study area despite the drastic changes occurred in cattle production system. However, 38% of herds did reach enzootic stability; therefore, a specific epidemiological status cannot be assumed at a regional level. Yearly determination of the immunological status of each calf cohort is considered a proper approach to decision-making in vaccination against B. bovis. [ABSTRACT FROM AUTHOR]