Virulence profiles of Shiga toxin-producing Escherichia coli and other potentially diarrheagenic E.coli of bovine origin, in Mendoza, Argentina

This study described a group of strains obtained from a slaughter house in Mendoza, in terms of their pathogenic factors, serotype, antibiotype and molecular profile. Ninety one rectal swabs and one hundred eight plating samples taken from carcasses of healthy cattle intended for meat consumption were analyzed. Both the swab and the plate samples were processed to analyze the samples for the presence of virulence genes by PCR: stx1, stx2, eae and astA. The Stx positive strains were confirmed by citotoxicity assay in Vero cells. The isolates were subsequently investigated for their O:H serotype, antimicrobial susceptibility and molecular profile by Random Amplification of Polymorphic DNA (RAPD). Twelve E.coli strains were identified by their pathogenicity. Nine were from fecal origin and three from carcasses. Three strains carried the stx1 gene, three the stx2 gene, two carried eae and four the astA gene. The detected serotypes were: O172:H-; O150:H8; O91:H21; O178:H19 and O2:H5. The strains showed a similarity around 70% by RAPD. Some of the E.coli strains belonged to serogroups known for certain life-threatening diseases in humans. Their presence in carcasses indicates the high probability of bacterial spread during slaughter and processing.

Virulence profiles of Shiga Toxin-Producing Escherichia coli and other potentially diarrheagenic E.coli of bovine origin, in Mendoza, Argentina.

This study described a group of strains obtained from a slaughter house in Mendoza, in terms of their pathogenic factors, serotype, antibiotype and molecular profile. Ninety one rectal swabs and one hundred eight plating samples taken from carcasses of healthy cattle intended for meat consumption were analyzed. Both the swab and the plate samples were processed to analyze the samples for the presence of virulence genes by PCR: stx1, stx2, eae and astA. The Stx positive strains were confirmed by citotoxicity assay in Vero cells. The isolates were subsequently investigated for their O:H serotype, antimicrobial susceptibility and molecular profile by Random Amplification of Polymorphic DNA (RAPD). Twelve E.coli strains were identified by their pathogenicity. Nine were from fecal origin and three from carcasses. Three strains carried the stx1 gene, three the stx2 gene, two carried eae and four the astA gene. The detected serotypes were: O172:H-; O150:H8; O91:H21; O178:H19 and O2:H5. The strains showed a similarity around 70% by RAPD. Some of the E.coli strains belonged to serogroups known for certain life-threatening diseases in humans. Their presence in carcasses indicates the high probability of bacterial spread during slaughter and processing.

[Changes in the etiology, outcome, and characteristics of patients with acute gastrointestinal bleeding between 1999 and 2005]. / Cambios en la etiología, resultados y características de los pacientes con hemorragia digestiva aguda grave a lo largo del perido 1999-2005.

OBJECTIVES: To analyze the evolution of the following variables in patients admitted to a Blood Unit for gastrointestinal bleeding throughout 1999-2005: etiology, comorbid diseases, use of NSAIDs/anticoagulants, and mortality. MATERIAL AND METHODS: We analyzed the evolution of the following causes of GIB that required admission to the Blood Unit from 1999 to 2005: duodenal ulcer (DU), gastric ulcer (GU), portal hypertension (PHT), and others. We also analyzed changes in the percentage of patients admitted with comorbid disease, use of NSAIDs/anticoagulants, and mortality. RESULTS: 1,611 Patients with a mean age of 60.45 years (59.7-61.2) were included in this study; 76.41% were males (74.3-78.5). DU was the cause of bleeding in 22.20% of cases (20.2-24.3), GU in 18.40% of cases (16.6-20.4), and PHT in 33.60% of cases (31.3-36.0). In all, 34.5% (32.6-37.3) of patients were taking NSAIDs, 7.1% (6.0-8.6) were receiving anticoagulant therapy, 72.6% (70.4-74.8) presented with comorbid disease, and overall mortality was 6.27% (5.16-7.59). Throughout the 1999-2005 period there was an increase in the number of patients with comorbid diseases (p < 0.02), and a decrease in cases of DU (p < 0.04), without significant differences in the remaining variables. CONCLUSIONS: DU, GU and PHT account for three quarters of admissions to our Blood Unit. Over the last seven years, there has been a decrease in cases due to DU, and an increase in patients with comorbid disease; overall mortality rates have remained stable.

Transfusion requirements in patients with gastrointestinal bleeding: a study in a Blood Unit at a referral hospital.

OBJECTIVES: 1. To study transfusion requirements in the Department of Gastroenterology of a Tertiary Referral Hospital, and their evolution over the last seven years. 2. To analyze risk factors associated with greater erythrocyte transfusion requirements. PATIENTS AND METHODS: erythrocyte transfusion requirements were compared for patients admitted to the Department of Gastroenterology at Hospital Virgen del Rocío, Seville, from 1999 to 2005. Clinical data of interest have been analyzed in order to determine factors associated with greater transfusion requirements. RESULTS: 1,611 patients with a mean age of 60.45 years (59.7-61.2) were included in this study; 76.41% were males. Gastric ulcers were the cause of bleeding in 18.4% of cases (with 69% requiring transfusions); duodenal ulcers caused 22.2% of cases (with 52.9% requiring transfusions), and portal hypertension caused 33.6% of cases (with 90.2% requiring transfusions). Upper and lower gastrointestinal bleeding of unknown origin requires transfusions in 88.9 and 96.2% of cases, respectively.A multivariate logistic regression analysis showed that clinical presentations such as hematemesis (odds ratio = 3.12), hematochezia (odds ratio = 33.17), gastrointestinal hemorrhage of unknown origin (odds ratio = 6.57), and hemorrhage as a result of portal hypertension (odds ratio = 3.43) were associated with greater transfusion requirements for erythrocyte concentrates. No significant differences were observed between the percentages of patients who received transfusions from 1999 to 2005. CONCLUSIONS: 1. No differences have been observed between the percentages of patients who received transfusions over the last seven years at our Department of Gastroenterology. 2. Patients presenting with hematemesis or hematochezia, in addition to those with bleeding of unknown origin or from portal hypertension, are prone to have greater transfusion requirements.

Evaluation of a multiplex PCR method to detect enteroaggregative Escherichia coli.

Enteroaggregative Escherichia coli (EAEC) has been implicated in sporadic diarrhea in children and adults and has been identified as the cause of several outbreaks worldwide. The HEp-2 test remains the gold standard for identification of this pathotype. A 60-65 MDa plasmid encodes the aggregative adherence fimbriae (AAF/I and AAF/II), a transcriptional activator (aggR gene), the enteroaggregative heat-stable enterotoxin EAST1 (astA gene) and a cytotoxin (Pet). The standard assay for EAEC is performed only in research laboratories, because it is expensive, labor intensive and time-consuming. The Polymerase Chain Reaction (PCR) offers the possibility of rapid diagnosis. In the current study, a multiplex PCR assay which checks aggR and astA genes was designed. Eigthy-eight E. coli strains, isolated from children with acute diarrhea in Mendoza, Argentina, were characterized by the reference method (HEp-2 assay), and by aggR-astA PCR. A strong correlation between the presence of the specific marker aggR and the reference test was found. The astA gene had a similar distribution between aggregative and localized strains, indicating that this gene could not be considered as a marker of EAEC. We conclude that aggR may be used to identify EAEC, using the PCR method as a screening test.

Evaluation of a multiplex PCR method to detect enteroaggregative Escherichia coli

Enteroaggregative Escherichia coli (EAEC) has been implicated in sporadic diarrhea in children and adults and has been identified as the cause of several outbreaks worldwide. The HEp-2 test remains the gold standard for identification of this pathotype. A 60-65 MDa plasmid encodes the aggregative adherence fimbriae (AAF/I and AAF/II), a transcriptional activator (aggR gene), the enteroaggregative heat-stable enterotoxin EAST1 (astA gene) and a cytotoxin (Pet). The standard assay for EAEC is performed only in research laboratories, because it is expensive, labor intensive and time-consuming. The Polymerase Chain Reaction (PCR) offers the possibility of rapid diagnosis. In the current study, a multiplex PCR assay which checks aggR and astA genes was designed. Eigthy-eight E. Coli strains, isolated from children with acute diarrhea in Mendoza, Argentina, were characterized by the reference method (HEp-2 assay), and by aggR-astA PCR. A strong correlation between the presence of the specific marker aggR and the reference test was found. The astA gene had a similar distribution between aggregative and localized strains, indicating that this gene could not be considered as a marker of EAEC. We conclude that aggR may be used to identify EAEC, using the PCR method as a screening test.

Evaluation of a multiplex PCR method to detect enteroaggregative Escherichia coli

Enteroaggregative Escherichia coli (EAEC) has been implicated in sporadic diarrhea in children and adults and has been identified as the cause of several outbreaks worldwide. The HEp-2 test remains the gold standard for identification of this pathotype. A 60-65 MDa plasmid encodes the aggregative adherence fimbriae (AAF/I and AAF/II), a transcriptional activator (aggR gene), the enteroaggregative heat-stable enterotoxin EAST1 (astA gene) and a cytotoxin (Pet). The standard assay for EAEC is performed only in research laboratories, because it is expensive, labor intensive and time-consuming. The Polymerase Chain Reaction (PCR) offers the possibility of rapid diagnosis. In the current study, a multiplex PCR assay which checks aggR and astA genes was designed. Eigthy-eight E. Coli strains, isolated from children with acute diarrhea in Mendoza, Argentina, were characterized by the reference method (HEp-2 assay), and by aggR-astA PCR. A strong correlation between the presence of the specific marker aggR and the reference test was found. The astA gene had a similar distribution between aggregative and localized strains, indicating that this gene could not be considered as a marker of EAEC. We conclude that aggR may be used to identify EAEC, using the PCR method as a screening test.(AU)

The -670A > G polymorphism in the promoter region of the FAS gene is associated with necrosis in periportal areas in patients with chronic hepatitis C.

Evidence suggests that apoptosis of liver cells may play a significant role in the pathogenesis of hepatitis C virus (HCV) infection. One of the best characterized apoptotic pathway is that mediated by the death receptor Fas. Fas expression has been found to be up-regulated on hepatocytes in chronic HCV infection, particularly in periportal areas. Recently, two polymorphisms have been identified in the promotor region of the FAS gene, -1377G > A and -670A > G. We have evaluated the involvement of these variants in the susceptibility to HCV infection, the severity of liver damage and progression of fibrosis in chronic hepatitis C. A cohort of 197 patients with chronic hepatitis C and 100 controls were analysed for both polymorphisms by Fluorescence Resonance Energy Transfer using specific probes and the Lightcycler system. In addition, liver biopsies were taken in 167 patients and scored using the Knodell classification system. We have found that the allele frequencies and the distribution of both polymorphisms do not differ significantly in the HCV cohort and in the control population. Thus, none of the polymorphisms seems to be related with susceptibility to HCV infection. However, we have examined the possible association between the two variants and the grade of necroinflammatory activity and the stage of fibrosis and we have detected an under-representation of the -670A > G variant among those patients with higher Knodell's scores (P = 0.049) and necroinflammatory activity (P = 0.036). The -670A allele was associated with higher levels of periportal necrosis (P = 0.012). In conclusion, our findings suggest an association between the -670A > G polymorphism and the grade of necrosis in periportal areas in patients with chronic hepatitis C.

Validity of early colonoscopy for the treatment of adenomas missed by initial endoscopic examination.

OBJECTIVE: To determine whether the features of adenomas identified in a first endoscopic examination may predict the presence of polyps with advanced pathological features that may have gone unnoticed and whether early colonoscopy may benefit these patients. MATERIAL AND METHODS: We examined 133 patients with diagnosis of colonic adenomas who had undergone complete colonoscopy and endoscopic polypectomy. All of them underwent colonoscopic follow-up at 3 years. Seventy nine patients underwent colonoscopic follow-up both at 6 months and at 3 years, while 54 patients underwent just colonoscopic follow-up at 3 years and 47 just at 6 months. RESULTS: Fifteen per cent of the patients analyzed developed polyps with pathological features after 6 months. The size and histological analysis of the polyps detected in the initial colonoscopic examination did not affect these results (p < 0.05). The number of polyps was statistically significant: patients with 3 or more polyps in the initial colonoscopic examination presented more polyps with pathological features after six months (25.8 versus 5.8%, p = 0002). This follow-up examination at 3 years did not reveal a higher occurrence of polyps with pathological features in any of the two groups of patients, namely, those who had undergone early colonoscopy and those who had not. CONCLUSIONS: Patients with multiple polyps have greater probability of developing synchronous polyps with some pathological features which may have gone unnoticed. Since early examination has not shown to provide a benefit for these patients, the first follow-up colonoscopy should be performed at 3 years, particularly if the initial colonoscopy is negative.

Flutamide-induced hepatotoxicity: report of a case series.

OBJECTIVE: To evaluate the characteristics of flutamide induced hepatotoxicity. MATERIAL AND METHODS: In this retrospective study we have analyzed all cases of flutamide hepatotoxicity submitted to the Andalucian Registry of drug-induced liver disease. Data were collected using a structured reporting form. Causality assessment was performed using two clinical scales: the standard CIOMS scale and the recently developed María and Victorino scale. RESULTS: Nine of 185 patients (4.9%) were identified. In 8 male patients, mean age 75 years (range 65-83), flutamide was indicated for palliative therapy of disseminated prostatic carcinoma, and in one young female (14 years) was given for the treatment of facial hirsutism. The mean duration of the flutamide therapy was 151 days (range 4-443). All patients presented with overt liver injury, the most frequent features being asthenia, anorexia, weight loss, nausea, vomiting and jaundice. No patient showed hypersensitivity features. In two patients (22%) the hepatic damage evolved to fulminant liver failure, one of them undergoing a liver transplantation and the other subsequently died. An additional patient died of a non-hepatic related cause when his liver function was improving. Causality assessment by the two clinical scales did not exclude any case, but the two patients who died where classified as unlikely by the María and Victorino scale. CONCLUSIONS: Flutamide can induce severe acute hepatitis, probably due to an idiosyncratic metabolic mechanism. Liver tests monitoring should probably be mandatory during the first months of flutamide therapy and the drug withdrawn if transaminases began to increase.

[Doses-related effects of lynestrenol on ovulation (author's transl)]. / Acción del linesternol sobre la ovulación. Importancia de la dosis.

PIP: 8 women, aged 22-28, with normal, ovulatory menstrual cycles, volunteered to take different doses of Lynestrenol to determine its effects on Luteineizing Hormone (LH) secretion, and on plasma progesterone levels. Blood samples were taken in the morning and plasma was immediately separated. Results showed that body temperature varied unpredictably during the cycle, and therefore could not be considered a reliable parameter of ovulation. 0.35 mg of Lynestrenol administered daily was enough to suppress ovulation, as evidenced by the absence of LH during midcycle. Although differences exists in individual reactions, administration of Lynestrenol beyond 0.6 mg. daily always suppresses ovulation because of hypothalamo-pituitary inhibition, while doses below 0.5mg. daily can bring about episodic peaks. It is still not clear how Lynestrenol influences gonadotropins, especially LH, while intermittent bleeding seems to be the only sure side effect.^ieng

Potentiation of adrenocortical response upon intermittent stimulation with corticotropin in normal subjects.

Modifications of adrenocortical steroidogenic response to ACTH as a consequence of acute prior exposure to this hormone, were studied in 106 normal subjects divided in 15 experimental groups. Adrenocortical response was assessed by the changes in plasma cortisol level and in urinary excretion of cortisol, 17-ketogenic and 17-ketosteroids; in some experiments plasma 11-deoxycortisol, corticosterone, progesterone and 17-hydroxyprogesterone were determined as well, together with urinary excretion of the unconjugated form of 11-deoxycortisol and corticosterone. Slow (8-h) intravenous administration of ACTH in amounts producing maximal response, leaves the adrenal cortex in a hyperresponsive state in case of further stimulation for up to 3 days, while the adrenocortical secretion comes back to baseline in the meantime. This potentiation phenomenon seems to concern essentially cortisol secretion since, among the compounds measured only cortisol and 11-deoxycortisol secretions increased progressively in amplitude when ACTH was administered repeatedly. Futhermore the degree of ACTH-induced adrenocortical hyperresponsiveness was found to depend on the amount of ACTH injected and on the time during which the adrenal cells are exposed to high peptide hormone concentrations. Increased adrenocortical responsiveness to ACTH persists when endogenous corticotropin secretion was suppressed for a few days by dexamethasone in normal subjects. Thus the potentiation phenomenon is not critically dependent on continued exposure of adrenal cells to endogenous corticotropin.