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A Mora

Publications and source records attributed to A Mora.

At least 55 records · Page 3Linked to original sources

Distribution and characterization of faecal verotoxin-producing Escherichia coli (VTEC) isolated from healthy cattle.

Faecal swabs obtained from a random sample of 268 cows and 90 calves on 19 Lugo farms were examined for verotoxin-producing Escherichia coli (VTEC). We found VTEC on 95% of the farms. The prevalence rates of VTEC infection in asymptomatic cows and calves were estimated to be 35 and 37%, respectively. The proportion of animals infected on each farm ranged from 0 to 100%. VTEC strains isolated from healthy cattle belonged to 27 O serogroups; however, 57% (85 of 149) were of one of 8 serogroups (O2, O8, O22, O77, O82, O105, O113 and O171). Nearly 60% of the bovine VTEC strains belonged to serogroups that cause haemorrhagic colitis and haemolytic uraemic syndrome in humans. The VTEC were all non-O157:H7; 91% were eae-negative and 86% produced VT2 or VT1 and VT2. These characteristics are different from those of VTEC isolated from calves with diarrhoea.

Animals↗

Detection of pap, sfa and afa adhesin-encoding operons in uropathogenic Escherichia coli strains: relationship with expression of adhesins and production of toxins.

A total of 243 Escherichia coli strains isolated from patients with urinary tract infections (UTI) were investigated for the presence of pap, sfa and afa adhesin-encoding operons by using the polymerase chain reaction. It was found that 54%, 53% and 2% of the strains exhibited the pap, sfa and afa genotypes, respectively. Pap+ and/or sfa+ strains were more frequent in cases of acute pyelonephritis (94%) than in cases of cystitis (67%) (P < 0.001) and asymptomatic bacteriuria (57%) (P < 0.001). The pap and/or sfa operons were found in 90% of strains expressing mannose-resistant haemagglutination (MRHA) versus 37% of MRHA-negative strains (P < 0.001). The presence of pap and sfa operons was especially significant in strains belonging to MRHA types III (100%) (without P adhesins) and IVa (97%) (expressing the specific Gal-Gal binding typical of P adhesins). Both pap and sfa operons were closely associated with toxigenic E. coli producing alpha-haemolysin (Hly+) and/or the cytotoxic necrotizing factor type 1. There was an apparent correlation between the pap and sfa operons and the O serogroups of the strains. Thus, 93% of strains belonging to O1, O2, O4, O6, O7, O14, O15, O18, O22, O75 and O83 possessed pap and/or sfa operons, versus only 32% of strains belonging to other serogroups (P < 0.001). The results obtained in this study confirm the usefulness of our MRHA typing system for presumptive identification of pathogenic E. coli exhibiting different virulence factors. Thus, 85% of strains that possessed both pap and sfa adhesin-encoding operons showed MRHA types III or IVa previously associated with virulence of E. coli strains that cause UTI and bacteraemia.

Adhesins, Escherichia coli↗

Prevalence and characteristics of enteropathogenic Escherichia coli with the eae gene in diarrhoeic rabbits.

A field study was carried out with the objective of investigating the prevalence of enteropathogenic Escherichia coli (EPEC) with the eae gene in diarrhoeic rabbits. EPEC eae+ were isolated from 60 (74%) of 81 diarrhoeic rabbits sampled in 30 industrial fattening farms localized in the four provinces of Galicia (northwestern Spain). Attaching and effacing lesions were found in 44 of 50 animals processed for histology. The 111 E. coli strains identified belonged to 19 different O serogroups and 13 biotypes. However, 53 (48%) of the strains belonged to serogroup O103 and 36 (32%) showed the serobiotype O103:B14. The eae gene was significantly more frequent (100%; 47 of 47) among the highly pathogenic rhamnose-negative strains of serobiotypes O103:B6 and O103:B14 than among the E. coli strains belonging to other serobiotypes (36%; 23 of 64) (P < 0.001). In this first report about the prevalence of EPEC with the eae gene in rabbits, we conclude that the class of E. coli strains observed is a common cause of diarrhoea in Galician rabbit farms, and that highly pathogenic rhamnose-negative strains of serotype O103:K-:H2 and biotype B14 are specially predominant.

Adhesins, Bacterial↗

Phase 1 trial of a candidate rotavirus vaccine (RV3) derived from a human neonate.

OBJECTIVE: To conduct a phase 1 safety and tolerability trial of an oral rotavirus vaccine candidate RV3 in healthy volunteers. METHODOLOGY: Double blind placebo controlled trial of a single 1 mL oral dose (6.5 x 10(5) fluorescing focus units [FFU]/mL) in 10 healthy young men, 10 3-4 year old children and 10 3 month old infants with a 4 week surveillance period. The study was undertaken at a children's hospital and nearby community in Melbourne, Australia. RESULTS: All subjects successfully completed the trial. There were no significant side-effects attributable to the vaccine preparation in any age group. No shedding of vaccine virus was detected by enzyme immunoassay. There was evidence of an immune response in serum and/or gut secretions in two of five vaccinees in each age group. CONCLUSION: RV3 rotavirus vaccine appears to be safe and well tolerated. Evidence of immunogenicity in some subjects after a single dose encourages further trials to determine immunogenicity after three doses, after reduction of viral dose, and without prior administration of buffer.

Administration, Oral↗

Production of toxins (enterotoxins, verotoxins, and necrotoxins) and colicins by Escherichia coli strains isolated from septicemic and healthy chickens: relationship with in vivo pathogenicity.

Since the mechanism of virulence of Escherichia coli strains pathogenic to birds is not fully understood, the prevalence of toxic factors produced by E. coli strains pathogenic to other animals was investigated. A total of 625 E. coli strains isolated from visceral organs of chickens with colisepticemia and from feces of healthy chickens in Spain were tested for production of enterotoxins (heat labile [LT] and heat stable [STa]), verotoxins (VT1, VT2, and VT2v), cytotoxic necrotizing factors (CNF1 and CNF2), alpha-hemolysin (Hly), enterohemolysin (EntHly), colicin V (Col V) and other types of colicins, and necrotic and lethal activities. Only 45 (7%) of avian E. coli strains were toxigenic: 20 strains produced a cytotoxic response in HeLa but not in Vero cells, indicating the production of a cytotoxin not related to the VTs; 16 were EntHly+; 5 produced a new cytotonic product that causes the appearance of whitish vacuola in Vero and HeLa cells; 3 synthesized soluble factors that cause lethal activity in mice; and 1 elaborated LT. None of 625 avian E. coli strains was positive for production of VTs or CNFs. In contrast, colicinogenicity occurred in 335 (73%) of the 458 septicemic strains and 97 (58%) of 167 fecal isolates (P < 0.01), and this property was correlated with in vivo pathogenicity of strains. Thus, 80% (P < 0.001) and 66% (P < 0.001) of strains producing Col V and other types of colicins were characterized as being of high pathogenicity, whereas only 15% of the noncolicinogenic strains were classified as highly pathogenic. Our results clearly support the special pathogenicity theory, because 60% of the E. coli strains belonging to 18 serogroups (O1, O2, O5, O8, O12, O14, O15, O18, O20, O53, O78, O81, O83, O102, O103, O115, O116, and O132) most frequently identified among clinical septicemic strains were classified as highly pathogenic in in vivo assays, whereas only 24% of the strains with O serogroups less prevalent among diseased chickens were considered highly pathogenic (P < 0.01).

Animals↗

Genes coding for enterotoxins and verotoxins in porcine Escherichia coli strains belonging to different O:K:H serotypes: relationship with toxic phenotypes.

Seventy-four E. coli strains isolated from piglets with diarrhea or edema disease in Spain were serotyped and examined for production of heat-labile (LT) and heat-stable (ST) enterotoxins (LT-I, LT-II, STaH, STaP, and STb) and verotoxins (VT1, VT2, and VT2v = VTe) by phenotypic (Vero cell assay and infant mouse test) and genotypic (colony hybridization and PCR) methods. In general, an excellent correlation was found between the results obtained with a PCR approach and those determined with biological assays. DNA probes used in the hybridization also showed a very good agreement with phenotypic results, with the exception of a VT1 probe that initially produced 10 false-positive reactions. The gene coding for STb (58 strains) was the most prevalent gene detected by PCR, followed by those coding for STa (46 strains), LT (19 strains), VT2v (11 strains), and VT1 (1 strain). Apparently, in Spain three seropathotypes are predominant: (i) O149:K91:H10 K88+ LT-I+ STb+, (ii) O141:K85ab:H- P987+ STaP+, and (iii) O138:K81:H14 or H- STaP+ VT2v+. We conclude that PCR is a fast, specific, and practical method for the identification of enterotoxin and VT genes in clinical and epidemiological studies.

Animals↗

Prevalence of bacterial resistance to quinolones and other antimicrobials among avian Escherichia coli strains isolated from septicemic and healthy chickens in Spain.

Antimicrobial therapy is an important tool in reducing the enormous losses in the poultry industry caused by Escherichia coli infections (colibacillosis). However, resistance to existing antimicrobials is widespread and of concern to poultry veterinarians. Antimicrobial resistance testing of 468 avian E. coli strains isolated in Spain showed very high levels of resistance to trimethoprim-sulfamethoxazole (67%) and the new fluoroquinolones (13 to 24%). As these antimicrobial agents may cause cross-resistance with human enteric pathogens, prudent use of them in veterinary medicine is highly recommended.

4-Quinolones↗

Activation of cellular immune response in acute pancreatitis.

BACKGROUND: Inflammatory mediators have recently been implicated as potential markers of severity in acute pancreatitis. AIMS: To determine the value of neopterin and polymorphonuclear (PMN) elastase as markers of activation of cellular immunity and as early predictors of disease severity. PATIENTS: Fifty two non-consecutive patients classified according to their clinical outcome into mild (n = 26) and severe pancreatitis (n = 26). METHODS: Neopterin in serum and the PMN elastase/A1PI complex in plasma were measured during the first three days of hospital stay. RESULTS: Within three days after the onset of acute pancreatitis, PMN elastase was significantly higher in the severe pancreatitis group. Patients with severe disease also showed significantly higher values of neopterin on days 1 and 2 but not on day 3 compared with patients with mild disease. There was a significant correlation between PMN elastase and neopterin values on days 1 and 2. PMN elastase on day 1 predicted disease severity with a sensitivity of 76.7% and a specificity of 91.6%. Neopterin did not surpass PMN elastase in the probability of predicting disease severity. CONCLUSIONS: These data show that activation of cellular immunity is implicated in the pathogenesis of acute pancreatitis and may be a main contributory factor to disease severity. Neopterin was not superior to PMN elastase in the prediction of severity.

Acute Disease↗

Abnormalities in the metabolism of acetaminophen in patients infected with the human immunodeficiency virus (HIV).

The urinary concentration of acetaminophen and its glucuronide, sulphate, cysteine, and mercapturate conjugates was measured by high-performance liquid chromatography in 32 healthy volunteers, 9 untreated symptom-free HIV-seropositive subjects, and 19 patients with AIDS after a single oral dose of 1.5 g of acetaminophen. The concentration of the glucuronide conjugate was significantly lower in AIDS patients when simultaneously compared with concentrations found in healthy individuals and symptoms-free HIV-seropositive subjects. Differences between healthy volunteers and symptom-free HIV seropositives were not encountered. By contrast, urinary concentrations of sulphate and oxidation pathway-derived metabolites were significantly higher in AIDS patients as compared with the other two groups. When AIDS patients treated with zidovudine were compared with those not given this medication, differences in the urinary excretion of acetaminophen and its metabolites were not observed. However, the urinary concentration of mercapturic acid was significantly higher in those given enzyme inducers, such as rifampicin or phenytoin, than in AIDS patients not treated with these drugs. In summary, patients with advanced HIV infection showed reduced acetaminophen glucuronidation and increased formation of the hepatotoxic oxidation metabolites, which was independent of zidovudine therapy.

Acetaminophen↗

Prevalence and characteristics of Escherichia coli serotype O157:H7 and other verotoxin-producing E. coli in healthy cattle.

From February to July of 1994, 328 faecal samples from 32 herds were collected and verotoxin-producing Escherichia coli (VTEC) found on 84% of the farms. The proportion of animals infected varied from 0-63%. VTEC were recovered from 52 (20%) of 257 cows and from 16 (23%) of 71 calves. Although the VTEC belonged to 25 different serogroups, 7 (O8, O20, O22, O77, O113, O126 and O162) accounted for 46% of strains. Nearly 45% of the strains. Nearly 45% of the 83 bovine VTEC strains belonged to serogroups associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. However, only 2 (2%) of 83 VTEC strains isolated from cattle belonged to enterohaemorrhagic E. coli (EHEC) serotypes (O26:H11 and O157:H7), and only 8 (10%) were positive for the attaching and effacing E. coli (eae) gene sequence. Polymerase chain reaction (PCR) showed that 17 (20%) of VTEC strains carried VT1 genes, 43 (52%) possessed VT2 genes, and 23 (28%) carried both VT1 and VT2 genes. Characterization of VTEC isolates revelated a heterogeneous population in terms of serogroup and toxin type in the positive herds. This study confirms that healthy cattle are a reservoir of VTEC, but, the absence of eae genes in most bovine VTEC strains suggests that they may be less virulent for humans than eae-positive EHEC.

Animals↗

The novel use of Rh(I) complexes with naphthyridine ligands and poly(oxyethylene) as antitumorals.

Rh(I) complexes adsorbed on polymers, as a way to improve their transport and solubility properties, were studied as antitumor agents. The binding constants of the complexes to the polymer were evaluated in order to determine the conditions for maximum association to the vehicle. The toxicity of the pure complexes and those bound were determined in vivo using female mice. [Rh(NBD)(2,4N)]CIO4, complex A; where NBD = norbornadiene, (2,4N) = 3,3'-dimethylene-2,2'-di-1,8-naphthyridine, was investigated on primary solid tumors and ascitic tumors. [Rh(NBD)(3,4N)]CIO4, complex B; where (3,4N) = 3,3'-trimethylene-2,2'-di-1,8-naphthyridine, was investigated on ascitic tumors. These Rh(I) complexes appear to be promising drugs because of their solubility in aqueous polymer, which make them easier to handle in comparison with the neutral species. These complexes show a similarity to cisplatin by reducing tumor growth and by increasing the survival life span of mice. Poly (oxyethylene) was used to solubilize these poorly water-soluble compounds and to stabilize the compounds in the solution before injection. These studies suggest that both complexes, A and B, are good candidates for tumor control growth and increase the survival time.

Animals↗

O serogroups, biotypes, and eae genes in Escherichia coli strains isolated from diarrheic and healthy rabbits.

A total of 305 Escherichia coli strains isolated from diarrheic and healthy rabbits in 10 industrial fattening farms from different areas of Spain were serotyped, biotyped, and tested for the presence of the eae gene and toxin production. The characteristics found in strains isolated from healthy rabbits were generally different from those observed in E. coli strains associated with disease. Thus, strains with the eae gene (74% versus 22%); strains belonging to serogroups O26, O49, O92, O103, and O128 (64% versus 12%); rhamnose-negative strains (51% versus 5%); and rhamnose-negative O103 strains with eae genes present (41% versus 1%) were significantly (P < 0.001 in all cases) more frequently detected in isolates from diarrheic animals than in those from healthy rabbits. Whereas a total of 35 serogroups and 17 biotypes were distinguished, the majority of the strains obtained from diarrheic rabbits belonged to only four serobiotypes, which in order of frequency were O103:B14 (72 strains), O103:B6 (16 strains), O26:B13 (12 strains), and O128:B30 (12 strains). These four serobiotypes accounted for 48% (112 of 231) and 5% (4 of 74) of the E. coli strains isolated from diarrheic and healthy rabbits, respectively. Only six strains were toxigenic (three CNF1+, two CNF2+, and one VT1+). We conclude that enteropathogenic E. coli strains that possess the eae gene are a common cause of diarrhea in Spanish rabbit farms and that the rhamnose-negative highly pathogenic strains of serotype O103:K-:H2 and biotype B14 are especially predominant. Detection of the eae gene is a useful method for the identification of enteropathogenic E. coli strains from rabbits. However, a combination of serogrouping and biotyping may be sufficient to accurately identify the highly pathogenic strains for rabbits.

Adhesins, Bacterial↗

Detection of enterohaemorrhagic Escherichia coli O157:H7 in minced beef using immunomagnetic separation.

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 has been recently recognized as a human pathogen associated with haemorrhagic colitis and haemolytic uraemic syndrome. Most outbreaks of haemorrhagic colitis resulted from the consumption of undercooked minced beef or raw milk. Dairy cattle have been identified as a reservoir of EHEC O157: H7. In this study E. coli O157 specific antibody, coated on magnetic beads, was used to concentrate and release EHEC O157:H7 from meat samples. A survey of retail fresh minced beef and hamburger samples using this procedure revealed that 3 (5%) of 58 beef samples were positive for EHEC O157:H7. Two of the strains produced both VT1 and VT2 verotoxins, and one produced only VT2. Immunomagnetic separation is a sensitive and simple technique for the isolation of E. coli O157 from food, and could be useful for a further elucidation of the epidemiology of this organism. The relatively high prevalence of EHEC O157:H7 in beef samples may constitute a risk for public health. Thus, a suitable epidemiologic control and effective methods of prevention should be applied.

Animals↗

[Orthotopic liver transplant for giant cavernous hemangioma and Kasabach-Merritt syndrome].

We describe the case of a 42-year-old woman with giant cavernous hemangioma and Kasabach-Merritt syndrome. The patient presented with consumption coagulopathy due to intravascular, intratumoral coagulation as revealed by low platelet levels, fibrinogenopenia and an increase in fibrinolysis with high levels of fibrinogen degradation products. She was scheduled to receive an orthotopic liver transplant because of three factors: respiratory distress caused by compression of the diaphragm by the giant tumor; the risk of bleeding caused by spontaneous rupture or trauma; and the presence of Kasabach-Merritt syndrome due to consumption coagulopathy. Before surgery fibrinogen deficit was corrected with 4 units of cryoprecipitates and low platelet level was treated with 10 units of platelets. Coagulopathy during surgery was corrected with fresh plasma (17 units), cryoprecipitates (6 U), aprotinin (1 x 10(6) U/kg) and antithrombin 3 (2000 U). Blood loss was compensated for with 9 units of packed red blood cells. This report describes the procedures used for anesthesia, for prevention of accidental bleeding during surgery, hemodynamic control and preoperative coagulation testing.

Adult↗