Seropositivity to Shiga toxin 2 among Argentinian urban and rural residents. Association with sociodemographic and exposure factors.

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.

An insight into population structure and genetic progress of Argentinean Holstein cattle.

The objective of the present study was to investigate the most critical issues associated with the limited genetic progress evidenced in the Argentinean Holstein ("Holando Argentino") breed in the last 20 years (only 26% of the phenotypic trend in milk yield was due to genetics). The study comprised the analysis of population structure, realized genetic selection differentials, genetic progress and partition of genetic trends by sex and country of origin from 1936 to 2019 (1,045,582 records; 24,680 sires and 619,322 dams in the pedigree). Average inbreeding steadily increased in the last 15 generations (ΔF = 0.6%, which translates to Ne = 75). Partition of genetic trends revealed that local genetics made a negligible contribution to genetic progress, which for most traits was highly dependent on imported genetics (>80%). Mean generation intervals were fairly constant until 2009 (8-9 years for males and 5-6 years for females, respectively) and then decreased, especially in the paths of sires of bulls and dams of bulls (to 5 and 4 years, respectively) mostly due to the influence of imported sires. The reduction in generation intervals was counterbalanced by a marked deterioration of realized selection differentials, particularly in the path of sires of bulls that nevertheless made the largest contribution to genetic progress. In the last 20 years, realized selection differentials in this path went from 533.6 to 170.8 kg for milk yield and from 16.7 to 13.3 kg for protein yield (1.7-0.5 and 1.6-1.3 standard deviation units, respectively). Among all considered traits (milk yield, fat yield, protein yield, stature, final score and daughter pregnancy rate) in the analysed period, annual genetic gain was negative for milk yield, fairly constant for composition and conformation traits, and positive only in the case of daughter pregnancy rate. Considered together, these results suggest that limited genetic progress is due to the absence of a sound breeding programme that includes genomic selection and a carefully defined selection objective, together with the absence of stronger regulations in germplasm importation; however, other factors such as potential genetics by environment interactions cannot be ruled out.

[Microbiological quality of fresh ground beef and detection of pathogens in environmental samples taken from butcher shops in the city of Tandil, Buenos Aires Province, Argentina]. / Calidad microbiológica de la carne picada y detección de patógenos en muestras ambientales de carnicerías de la ciudad de Tandil, provincia de Buenos Aires, Argentina.

The aim of this work was to evaluate the hygienic-sanitary conditions of butcher shops in Tandil, Buenos Aires Province, by estimating the risk based on good manufacturing and hygiene practices, through surveys of the establishments. The analysis was performed using a scale of 1-100, and classifying them as high risk (0-40), moderate risk (41-70) or low risk (71-100). The presence of Salmonella spp., Staphylococcus aureus and Shiga toxin-producing Escherichia coli (STEC) from both, ground beef and environmental samples such as countertop, cleaver, mincer and butcher's hands, taken at butcher shops was also evaluated. Sampling was performed only once and immediately refrigerated and transported to the laboratory for analysis. All butcher shops evaluated (100) were classified as "low risk" with good hygienic-sanitary conditions. However, 75% of the ground beef samples analyzed did not meet at least one of the microbiological criteria established in the Código Alimentario Argentino [Argentine Food Code], article 255. We propose to establish a strategy to identify deviations and implement a plan for continuous improvement in butcher shops of Tandil city.

Effect of short-term artificial light and transvaginal progesterone device on first ovulation in late transitional mares.

In study I, plasma progesterone concentrations were evaluated in anoestrous mares that received an intravaginal progesterone release device (IPRD) for 10 days. Mares were divided into 3 groups based on the dosage of progesterone (0 g, n=3; 1.38 g, n=5; and 1.9 g, n=5). No statistical differences were found in plasma progesterone concentrations between the two doses tested. In study II, the effects of a protocol based on a short program of artificial light combined with an IPRD containing 1.38 g of progesterone on oestrous behaviour and onset of ovulation were evaluated. IPRDs were inserted into 31 late transitional mares (10 days of treatment). The mares were divided into a control group (n=9, IPRD with 0 g of progesterone) and two treatment groups (T1, n=10, IPRD with 0 g of progesterone and artificial light; T2, n=12, IPRD with 1.38 g of progesterone and artificial light). The percentages of mares in heat within the first 14 days after treatment were 100%, 70%, and 100% in the control, T1, and T2 groups, respectively (P=0.097), and their ovulation rates were 44%, 60%, and 100%, respectively (P≤0.01). In conclusion, a protocol based on artificial light and an IPRD containing 1.38 g of progesterone for 10 days could be considered to advance the first ovulation of the year in late transitional mares, as it ensures a higher rate of ovulation within the first 14 days after treatment.

Influence of faecal culture media and incubation time on the yield of infective larvae of Haemonchus contortus (Rudolphi 1803).

The aim of this experiment was to determine the yield of Haemonchus contortus third-stage larvae (L3) in faecal cultures in different conditions, including incubation time (7 or 14 days), the addition of inert additives (polystyrene pellets, vermiculite or no additive) and physical condition of the incubated faeces (ground or whole pellets). Twelve groups of 10 cultures each were arranged and incubated at 24 °C to evaluate the interaction of the above-mentioned conditions. Significantly, more L3 (p=0.0019 to p=0.0200) were recovered from cultures incubated for 7 days than for 14 days, except for the groups containing whole pellets with no additives (p=0.53) or with vermiculite (p=0.41). Larval yields from 7-day incubated cultures did not differ between groups (p=0.47), but for the whole pellets with vermiculite group, which yielded significantly less L3 (p<0.0001) than the rest of the cultures. Incubation for 14 days showed that cultures containing whole pellets with no additives yielded significantly more L3 (p<0.05) than the rest. Culturing faeces with H. contortus seems not to require inert additives or extra manipulation to obtain good L3 yields.

Individual and combined presenilin 1 and 2 knockouts reveal that both have highly overlapping functions in HEK293T cells.

Presenilins 1 and 2 (PS1 and 2) are the catalytic subunits of γ-secretase, a multiprotein protease that cleaves amyloid protein precursor and other type I transmembrane proteins. Previous studies with mouse models or cells have indicated differences in PS1 and PS2 functions. We have recently reported that clinical γ-secretase inhibitors (GSIs), initially developed to manage Alzheimer's disease and now being considered for other therapeutic interventions, are both pharmacologically and functionally distinct. Here, using CRISPR/Cas9-based gene editing, we established human HEK 293T cell lines in which endogenous PS1, PS2, or both have been knocked out. Using these knockout lines to examine differences in PS1- and PS2-mediated cleavage events, we confirmed that PS2 generates more intracellular ß-amyloid than does PS1. Moreover, we observed subtle differences in PS1- and PS2-mediated cleavages of select substrates. In exploring the question of whether differences in activity among clinical GSIs could be attributed to differential inhibition of PS1 or PS2, we noted that select GSIs inhibit PS1 and PS2 activities on specific substrates with slightly different potencies. We also found that endoproteolysis of select PS1 FAD-linked variants in human cells is more efficient than what has been previously reported for mouse cell lines. Overall, these results obtained with HEK293T cells suggest that selective PS1 or PS2 inhibition by a given GSI does not explain the previously observed differences in functional and pharmacological properties among various GSIs.

Effect of the combination of crude extracts of Penicillium griseofulvum and Fusarium graminearum containing patulin and zearalenone on rumen microbial fermentation and on their metabolism in continuous culture fermenters.

Six single-flow continuous cultures were used to study the effects of the mycotoxins patulin (PAT) and zearalenone (ZEN) alone or in combination on rumen microbial fermentation. In each of the four 7-d periods, the fermenters were supplemented in a 2 × 3 factorial arrangement with two levels of PAT (0 and 20 mg/l) and three levels of ZEN (0, 5 and 10 mg/l). The treatments did not affect the apparent and true digestibility of organic matter. PAT alone decreased the digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) (p < 0.01), but in the presence of 5 or 10 mg/l of ZEN, there were no effects of PAT. In contrast, the digestibility of NDF and ADF was decreased at 10 mg/l of ZEN in the absence of PAT (p < 0.05). The pH of the fermenters increased after 2 and 3 d of PAT treatment (p < 0.01). PAT decreased the concentration of total volatile acids (VFA), the molar proportion of acetate and the acetate:proportionate ratio (p < 0.01). The molar concentrations of other VFA were unchanged. Ammonia N (NH3-N) flow increased (p < 0.05) and there was a tendency to a higher NH3-N concentration (p < 0.1) in fermenters with PAT. Total N, non-ammonia N and bacterial N as well as efficiency of microbial protein synthesis and efficiency of N utilisation were not affected by treatments. PAT was nearly completely degraded during incubation. The mean recovery of ZEN, α-zearalenol and ß-zearalenol expressed as a proportion of administered ZEN was less than 50% in effluents from fermenters receiving only ZEN and ZEN plus PAT, respectively. With exception of fibre digestion, the co-administration of PAT and ZEN did not elicit interaction effects on most measured parameters of rumen metabolism.

[Epidemiology of hemolytic uremic syndrome in two regions of Buenos Aires Province]. / Epidemiología del síndrome urémico hemolítico en dos regiones de la Provincia de Buenos Aires.

The objectives of this study were (a) to describe and estimate the frequency of hemolytic uremic syndrome (HUS) in rural and urban populations in two regions of Buenos Aires Province, and (b) to compare the presentation and distribution of factors hypothetically associated with HUS. A total of 82 HUS cases, recorded during the years 2005-2010 in rural and urban areas of the south-central region of Buenos Aires Province, were clinically and epidemiologically characterized. Statistical data analysis included Chi square or Fisher test and median test. The incidence rate of HUS was significantly higher in the rural population, being 12.7 cases per 100 000 (CI 0-23.5) in rural inhabitants vs. 7.1 cases per 100 000 (CI 0-9.5) in urban inhabitants. The median age of the patients was 27 months (5-139 months), significantly lower in children from the rural area. This could be explained by a more frequent contact with bovine feces, the consumption of raw milk and a higher proportion of relatives who work in risk labors found in the rural population. Although HUS is often associated with the consumption of undercooked minced meat, most of the children cases here included did not present this antecedent. Clinical manifestations were similar in both subpopulations. One-third of urban patients had received antibiotics prior to HUS development.

The efficacy of trichlorphon and naphthalophos against multiple anthelmintic-resistant nematodes of naturally infected sheep in Argentina.

An anthelmintic efficacy trial was conducted in sheep harbouring anthelmintic-resistant worms in Argentina. Seventy lambs were selected from a flock that had been grazed on pastures infected with trichostrongyles previously shown to be resistant to the main anthelmintic groups. Lambs were allocated to comparable groups of ten animals each and treated with trichlorphon (50 mg/kg body weight (b.w.) orally); naphthalophos (50 mg/kg b.w. orally); ivermectin (0.2 mg/kg b.w. subcutaneously); fenbendazole (5 mg/kg b.w. orally); levamisole (8 mg/kg b.w. subcutaneously) and closantel (10 mg/kg b.w. orally). There was also an untreated group. The dose selection was based on manufacturer's recommendations.Faecal samples were collected 0 and 10 days post treatment to estimate efficacy (faecal egg count reduction). Six animals from each group were necropsied at day 10 for enumeration/identification of worms from the abomasum, small and large intestines to determine the absolute efficacy of each agent (controlled efficacy test). Trichlorphon and naphthalophos were effective (> 99 %) against Haemonchus contortus (p < 0.05).Naphthalophos also showed efficacy against Trichostrongylus axei (99.3 %), Teladorsagia circumcincta (97.8 %), Trichostrongylus colubriformis (99.2 %), Cooperia punctata/curticei/pectinata (90.4 %), Nematodirus spathiger (89.2 %) and Oesophagostomum venulosum/columbianum (93.7 %). Fenbendazole and levamisole showed efficacy (> 95 %) against all nematodes except T. colubriformis. The efficacy of ivermectin was low against H. contortus (23 %) and Cooperia spp. (46.3 %). Closantel showed low efficacy against T. axei (64.4 %), H. contortus (80.6 %) and T. colubriformis (59.5 %).When anthelmintic resistance is widespread, trichlorphon treatment is appropriate if H. contortus is present; however, naphthalophos represents an effective therapeutic alternative for incorporation into worm control programmes.

Environmental monitoring of ivermectin excreted in spring climatic conditions by treated cattle on dung fauna and degradation of faeces on pasture.

The effect of ivermectin excreted in faeces of cattle treated in late winter on the arthropods and the degradation of faeces on pasture were evaluated. Four calves of similar age and weight were allocated to two groups, one group was treated subcutaneously with ivermectin and the other group remained as untreated control. From faeces collected from both groups at 3, 7, 14, 21 and 28 days post-treatment (dpt), three faecal pats of 1 kg each were made and deposited on a mixed paddock. One quarter of each faecal pat was removed at 10, 20, 30 and 60 days postdeposition (dpd) to determine the concentration of ivermectin, the organic matter content, and to collect colonising dung arthropods. Concentrations at days 3 and 7 pt were significantly higher than at the other dpt (p<0.05). The highest ivermectin concentrations were found in samples from 3 dpt (p<0.05). The organic matter percentage was not significantly different between treatments. An edaphic fauna characterised the colonisation of the faeces by organisms. Although arthropods' abundance differences were not significant except for the 28 dpt at 30 dpd (p<0.0003), fewer organisms were collected from the ivermectin group at all times.

Factors associated with sporadic verotoxigenic Escherichia coli infection in children with diarrhea from the Central Eastern Area of Argentina.

Verotoxigenic Escherichia coli (VTEC) are one of the most important emerging foodborne pathogens and the principal cause of hemolytic uremic syndrome (HUS). This entity has been recognized worldwide as a priority issue in the field of zoonoses and public health, and Argentina is the country with the highest incidence of HUS in children less than 5 years of age.The lack of specific treatment, combined with the high morbidity rate of VTEC infection, makes prevention the main tool for reducing the incidence of HUS. The current work aimed at assessing the factors associated with sporadic VTEC infection in children with acute diarrhea from the Central Eastern area of Argentina where the incidence rate of HUS in children under 5 is the highest worldwide. A univariate analysis was performed to identify potential factors associated with VTEC infection by calculating odds ratios (OR) with 95% confidence intervals (CI). Then, a multivariate logistic regression model was performed. Interaction and association between significant factors were checked. "Recent consumption of food prepared outside home" (OR: 2.4, 95% CI 1.05-5.7) and "recent vegetables consumption" (OR=0.4; 0.2-0.8) were identified as independent factors associated with VTEC infection. We believe that the data obtained from this study further the current knowledge about the epidemiology of VTEC infection in Argentina and could be considered when planning strategies for the prevention of the disease.

γ-Secretase modulators exhibit selectivity for modulation of APP cleavage but inverse γ-secretase modulators do not.

BACKGROUND: γ-Secretase is a multiprotein protease that cleaves amyloid protein precursor (APP) and other type I transmembrane proteins. It has two catalytic subunits, presenilins 1 and 2 (PS1 and 2). In our previous report, we observed subtle differences in PS1- and PS2-mediated cleavages of select substrates and slightly different potencies of PS1 versus PS2 inhibition for select γ-secretase inhibitors (GSIs) on various substrates. In this study, we investigated whether γ-secretase modulators (GSMs) and inverse γ-secretase modulators (iGSMs) modulate γ-secretase processivity using multiple different substrates. We next used HEK 293T cell lines in which PSEN1 or PSEN2 was selectively knocked out to investigate processivity and response to GSMs and iGSMs. METHODS: For cell-free γ-secretase cleavage assay, recombinant substrates were incubated with CHAPSO-solubilized CHO or HEK 293T cell membrane with GSMs or iGSMs in suitable buffer. For cell-based assay, cDNA encoding substrates were transfected into HEK 293T cells. Cells were then treated with GSMs or iGSMs, and conditioned media were collected. Aß and Aß-like peptide production from cell-free and cell-based assay were measured by ELISA and mass spectrometry. RESULT: These studies demonstrated that GSMs are highly selective for effects on APP, whereas iGSMs have a more promiscuous effect on many substrates. Surprisingly, iGSMs actually appear to act as like GSIs on select substrates. The data with PSEN1 or PSEN2 knocked out HEK 293T reveal that PS1 has higher processivity and response to GSMs than PS2, but PS2 has higher response to iGSM. CONCLUSION: Collectively, these data indicate that GSMs are likely to have limited target-based toxicity. In addition, they show that iGSMs may act as substrate-selective GSIs providing a potential new route to identify leads for substrate-selective inhibitors of certain γ-secretase-mediated signaling events. With growing concerns that long-term ß-secretase inhibitor is limited by target-based toxicities, such data supports continued development of GSMs as AD prophylactics.

Effect of fosfomycin, Cynara scolymus extract, deoxynivalenol and their combinations on intestinal health of weaned piglets.

Weaning is a challenging stage of pig farming. Animals undergo environmental, social and dietary changes leading to weaning stress syndrome. In order to compensate for the detrimental effects of weaning stress, antibiotics and natural extracts are used as feed additives, sometimes without fully understanding the interactions between them or even with low concentrations of mycotoxins that are frequently present in feed. The aim of this study was to evaluate the effect of fosfomycin (FOS), Cynara scolymus extract (CSE), deoxynivalenol (DON) and their combined administration on intestinal health of weaned piglets. The experiment was designed as a 2 × 2 × 2 factorial arrangement with 3 factors (FOS, CSE and DON treatments), 2 levels each (presence and absence) and 3 repeats. Weaned piglets (n = 24) were randomly divided in groups to receive the different treatments, namely DON administered in diet (50 µg/kg BW), FOS administered into the drinking water (30 mg/kg BW), CSE administered in diet (15 mg/kg BW) and all their combinations. After 15 d, the animals were euthanized and gastrointestinal tract samples were immediately taken to evaluate gastrointestinal pH, Enterobacteriaceae to lactic acid bacteria (E:L) ratio, volatile fatty acid (VFA) concentrations, disaccharidase (lactase, sucrase and maltase) activity, histology (intestinal absorptive area [IAA] and goblet cells count) and mucus ability to adhere pathogenic Escherichia coli. From our results, FOS and CSE treatments, individually or combined, produced a lower E:L ratio, an enhanced production of butyrate, increased disaccharidase activity (particularly maltase), and a greater IAA and goblet cells count along with an increase in pathogenic bacteria adherence to intestinal mucus. Deoxynivalenol did not show interactions with the other factors and its administration produced decreases on VFA, disaccharidase activity and goblet cells count. In conclusion, weaning piglets receiving diets containing FOS, CSE or both exhibited evident beneficial intestinal effects compared to animals receiving diets free from these compounds. On the contrary, the presence of DON at sub-toxic concentrations produced detrimental effects on intestinal health. The knowledge of the physiological and pathological gut changes produced by these compounds contributes to understand their potential productive consequences.

A novel proteotoxic combination therapy for EGFR+ and HER2+ cancers.

While HER2 and EGFR are overexpressed in breast cancers and multiple other types of tumors, the use of EGFR and/or HER2 inhibitors have failed to cure many cancer patients, largely because cancers acquire resistance to HER2/EGFR-specific drugs. Cancers that overexpress the HER-family proteins EGFR, HER2, and HER3 are uniquely sensitive to agents that disrupt HER2 and EGFR protein folding. We previously showed that disruption of disulfide bond formation by Disulfide Disrupting Agents (DDAs) kills HER2/EGFR overexpressing cells through multiple mechanisms. Herein, we show that interference with proline isomerization in HER2/EGFR overexpressing cells also induces cancer cell death. The peptidyl-prolyl isomerase inhibitor Cyclosporine A (CsA) selectively kills EGFR+ or HER2+ breast cancer cells in vitro by activating caspase-dependent apoptotic pathways. Further, CsA synergizes with the DDA tcyDTDO to kill HER2/EGFR overexpressing cells in vitro and the two agents cooperate to kill HER2+ tumors in vivo. There is a critical need for novel strategies to target HER2+ and EGFR+ cancers that are resistant to currently available mechanism-based agents. Drugs that target HER2/EGFR protein folding, including DDAs and CsA, have the potential to kill cancers that overexpress EGFR or HER2 through the induction of proteostatic synthetic lethality.

[National Nursing Consensus on management of severe traumatic brain injury in children]. / Consenso Nacional de Enfermería sobre el manejo del niño con lesión cerebral por traumatismo de cráneo grave.

The nursing professional who treats critically ill children with cerebral injury is a key element within the pediatric intensive care team, since, through exhaustive assessment, plans nursing care in an integral manner aimed at the child and the family, and plays an essential role in the care of patients mainly at the hospital level (as well as at home). Therefore, the role played by nursing in the care of children with severe brain trauma is crucial. This guide offers nursing recommendations on neurocritical care, focusing on a systemic view based on nursing diagnoses according to the North American Nursing Diagnosis Association.

El profesional de enfermería que atiende a niños críticamente enfermos con lesión cerebral es un miembro clave dentro del equipo intensivista pediátrico, ya que, mediante la evaluación exhaustiva, planifica cuidados de enfermería de manera integral dirigidos al niño y a la familia. La enfermería como una profesión que entiende la salud de la persona humana desde una mirada integral cumple un rol esencial (indispensable) en el cuidado de los pacientes, principalmente, a nivel hospitalario (como domiciliario). Por ende, el rol que juega la enfermería en la atención de un niño con traumatismo encéfalocraneano grave es crucial en la gestión del cuidado infantil. Esta guía ofrece recomendaciones de enfermería sobre los cuidados neurocríticos focalizando una mirada sistémica basada en diagnósticos de enfermería según la Asociación Americana de Diagnósticos de Enfermería.

Variation in the Distribution of Putative Virulence and Colonization Factors in Shiga Toxin-Producing Escherichia coli Isolated from Different Categories of Cattle.

Shiga toxin-producing Escherichia coli (STEC) are pathogens of significant public health concern. Several studies have confirmed that cattle are the main reservoir of STEC in Argentina and other countries. Although Shiga toxins represent the primary virulence factors of STEC, the adherence and colonization of the gut are also important in the pathogenesis of the bacteria. The aim of this study was to analyze and to compare the presence of putative virulence factors codified in plasmid -katP, espP, subA, stcE- and adhesins involved in colonization of cattle -efa1, iha- in 255 native STEC strains isolated from different categories of cattle from different production systems. The most prevalent gene in all strains was espP, and the less prevalent was stcE. katP was highly detected in strains isolated from young and rearing calves (33.3%), while subA was predominant in those isolated from adults (71.21%). Strains from young calves showed the highest percentage of efa1 (72.46%), while iha showed a high distribution in strains from rearing calves and adults (87.04 and 98.48% respectively). It was observed that espP and iha were widely distributed throughout all strains, whereas katP, stcE, and efa1 were more associated with the presence of eae and subA with the eae-negative strains. A great proportion of eae-negative strains were isolated from adults -dairy and grazing farms- and from rearing calves -dairy and feedlot-, while mostly of the eae-positive strains were isolated from dairy young calves. Data exposed indicate a correlation between the category of the animal and the production systems with the presence or absence of several genes implicated in adherence and virulence of STEC.

Calidad microbiològica de la carne picada y detección de patógenos en muestras ambientales de carnicerías de la ciudad de Tandil, provincia de Buenos Aires,Argentina / Microbiological quality of fresh ground beef and detection of pathogens in environmental samples taken from butcher shops in the city of Tandil, Buenos Aires Province, Argentina

Resumen Este estudio evaluó las condiciones higiénico-sanitarias de carnicerías de la ciudadde Tandil (provincia de Buenos Aires) mediante una estimación del riesgo basada en encuestasdirigidas a revisar las buenas prácticas de manufactura y de higiene de los establecimientos. Seutilizó una escala de 1 a 100 para clasificar a los establecimientos en las categorías de riesgoalto (0-40), riesgo moderado (41-70) y riesgo bajo (71-100). A su vez, se evaluó la presencia deSalmonella spp., Staphylococcus aureus, Escherichia coli productor de toxina Shiga (STEC) encarne bovina picada y en muestras ambientales como mesada, cuchilla, picadora y manos delcarnicero. Las muestras se tomaron una sola vez e inmediatamente se refrigeraron y transpor-taron al laboratorio para su análisis. En el período de estudio todas las carnicerías (100) fueronclasificadas como de «riesgo bajo¼ y con buenas condiciones higiénico-sanitarias. No obstante,el 75% de las muestras de carne picada no cumplió con al menos uno de los criterios microbiológicos establecidos en el Artículo 255 del Código Alimentario Argentino. Se sugiere estableceruna estrategia tendiente a identificar los desvíos e implementar un plan de mejoras continuasen las carnicerías de la ciudad de Tandil.

Abstract The aim of this work was to evaluate the hygienic-sanitary conditions of butcher shops in Tandil, Buenos Aires Province, by estimating the risk based on good manufacturing and hygiene practices, through surveys of the establishments. The analysis was performed using a scale of 1-100, and classifying them as high risk (0-40), moderate risk (41-70) or low risk (71-100). The presence of Salmonella spp., Staphylococcus aureus and Shiga toxin-producing Escherichia coli (STEC) from both, ground beef and environmental samples such as countertop, cleaver, mincer and butcher's hands, taken at butcher shops was also evaluated. Sampling was performed only once and immediately refrigerated and transported to the laboratory for analysis. All butcher shops evaluated (100) were classified as "low risk'' with good hygienic-sanitary conditions. However, 75% of the ground beef samples analyzed did not meet at least one of the microbiological criteria established in the Código Alimentario Argentino [Argentine Food Code], article 255. We propose to establish a strategy to identify deviations and implement a plan for continuous improvement in butcher shops of Tandil city.

Treatment of osteochondral lesions of the talus with cryopreserved talar allograft and ankle distraction with external fixation.

This article presents the results of a retrospective review of six osteochondral lesions on six patients (five men and one woman) treated with transplantation of cryopreserved talar allograft and ankle joint distraction. All patients complained of ankle pain existing for a long time secondary to a traumatic episode confirmed through MRI. Lesions ranged in measurement from 0.8 cm x 0.8 cm to 3.2 cm x 1.8 cm with an average size of 2.1 cm x 1.5 cm. Each patient underwent talar dome transplantation using fresh frozen talar allograft followed by ankle distraction. Distraction was obtained using a three-ring multiplanar external fixation device. All surgeries were performed between 2002 and 2004. All external fixators were removed at 8 weeks and patients remained partial-weight bearing in a removable cast boot for an additional 8 weeks. Serial postoperative radiographs showed complete consolidation of the allograft within 16 weeks. The average follow up time was 24 months, and all patients related a subjective decrease in symptoms and increase in activity levels. Patients were also evaluated utilizing the Maryland Foot Score both pre- and postoperatively. Preoperatively, four patients were graded as fair and two were graded as poor. Postoperatively, two patients related excellent results, three patients related good results, and one patient related fair results. Several patients experienced minor complications such as pin site irritation (five patients), painful talar wire (one patient), and periostitis (one patient). No patients experienced any major complications and none have required additional surgery. We feel that these initial results warrant further investigation of this treatment.

Evaluation of the time of uncapping and removing dead brood from cells by hygienic and non-hygienic honey bees.

Most research on hygienic behavior has recorded the time taken by the colony to remove an experimental amount of dead brood, usually after one or two days. We evaluated the time that hygienic (H) and non-hygienic (NH) honey bees take to uncap and remove dead brood in observation hives after the brood was killed using the pin-killing assay. Four experimental colonies were selected as the extreme cases among 108 original colonies. Thirty brood cells were perforated with a pin in two H and two NH colonies and observations were made after 1, 2, 3, 4, 5, 6, and 24 h. Different stages of uncapping and removing were recorded. Differences in uncapping and removal between H and NH colonies were significant for all comparisons made at the different times after perforation. Using observation hives one obtains a better and faster discrimination between H and NH colonies than in full size colonies. It is possible to differentiate H and NH within a few hours after perforating the cells.

Detection of Integrase Gene in E. coli Isolated from Pigs at Different Stages of Production System.

Integrons are one of the genetic elements involved in the acquisition of antibiotic resistance. The aim of the present research is to investigate the presence of integrons in commensal Escherichia coli (E. coli) strains, isolated from pigs at different stages of production system and from the environment in an Argentinian farm. Five sows postpartum and five randomly chosen piglets from each litter were sampled by rectal swabs. They were sampled again at day 21 and at day 70. Environmental samples from the farm were also obtained. E. coli containing any integron class or combination of both integrons was detected by polymerase chain reaction in 100% of sows and in piglets at different stages of production: farrowing pen stage 68.1%;, weaning 60%, and growing/finishing 85.8%, showing an increase along the production system. From environmental samples 78.4% of E. coli containing any integron class was detected. We conclude that animals and farm environment can act as reservoirs for potential spread of resistant bacteria by means of mobile genetic elements as integrons, which has a major impact on production of food animals and that can reach man through the food chain, constituting a problem for public health.