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N Serrano

Publications and source records attributed to N Serrano.

34 records · Page 2Linked to original sources
PubMed1995

Unusually large number of methicillin-resistant Staphylococcus aureus clones in a Portuguese hospital.

Methicillin-resistant Staphylococcus aureus (MRSA) has been endemic in Hospital de Santa Maria, a 1,300-bed teaching hospital in Lisbon, Portugal, since the mid-1980s with a prevalence of 30% in 1993. A total of 54 MRSA and 93 methicillin-susceptible S. aureus (MSSA) isolates recovered during the first 3 months of 1993 were analyzed for the particular mecA polymorphs and Tn554 attachment sites (in the case of MRSA) and for pulsed-field gel electrophoretic patterns. While all MRSA isolates shared a very similar multidrug resistance antibiogram, molecular methods allowed the identification of an unusually large number of genetic backgrounds (24 different pulsed-field gel electrophoresis patterns in 54 isolates) and three different mecA polymorphs among the MRSA strains. Similar large variation in the genetic backgrounds of MSSA was observed. The most frequent mecA polymorph (mecA type I) was found in association with three different Tn554 patterns. Among the MRSA strains of Hospital Santa Maria, we found two clonal types previously described in Portugal: one corresponding to the dominant clone in an MRSA outbreak at the pediatric ward of the Lisbon Hospital Dona Estefânia and another one identical to the Iberian epidemic clone identified in several Portuguese hospitals and in MRSA outbreaks in Barcelona and Madrid. This suggests that MRSA clones of Hospital de Santa Maria may have been a reservoir for staphylococcal strains over the past decade.

Bacterial Typing Techniques↗
PubMed1995

polyhomeotic appears to be a target of engrailed regulation in Drosophila.

In Drosophila, Engrailed is a nuclear regulatory protein with essential roles in embryonic segmentation and in normal development of posterior compartments. One of its regulatory targets appears to be polyhomeotic (ph), a Polycomb group gene. We observed, by immunostaining, that Engrailed protein binds to the site of the polyhomeotic locus in region 2D of polytene chromosomes. The same analysis carried out on a transgenic line containing one copy of a P(ph-lacZ) construct shows an additional Engrailed-binding site at the location of the insert. In vivo, polyhomeotic depends on engrailed function in germ-band-elongated embryos, when engrailed and polyhomeotic genes are expressed in similar patterns. By in vitro immunoprecipitations and gel shift assays, we identified two classes of high affinity Engrailed-binding sites upstream of each of the two polyhomeotic transcription units. DNA fragments containing these sites were also immunoprecipitated from embryonic UV crosslinked chromatin in presence of anti-Engrailed antibody. These results suggest that polyhomeotic activation in germ-band-elongated embryos could be mediated by Engrailed-binding to these sites.

Animals↗
PubMedDate not supplied

[The diversity of Staphylococcus aureus strains isolated in a Lisbon hospital over a 4-year period].

Over a 4-year period, 2020 Staphylococcus aureus strains isolated in Santa Maria Hospital were studied, 26.3% of which were methicillin-resistant (MRSA). The main specimens from which the strains were isolated included pus, blood and sputum/bronchial secretions. Isolation in blood cultures was the most common source among patients from medical units. Antimicrobial susceptibility studies showed that while in methicillin susceptible strains sensitivity to other antimicrobial agents (apart from penicillin resistance) was the rule, in MRSA strains there was resistance to most antibiotics. Only vancomycin was active against all strains. Phage typing showed that 75.5% of the strains were typable with phages at 100 x R.T.D. Among methicillin sensitive strains, a big diversity of phage patterns was observed, including phage groups I, II, III and V, as well as with phage association D11/95. The large majority of MRSA strains were lysed by group III phages, although several distinct patterns were observed. Within these strains, lysis by groups II and V phages was not observed. Plasmid profiling was the least discriminant issue in the characterization of these micro-organisms because most of the strains harboured only one plasmid (or none). These results showed that a dominant MRSA strain did not exist in this hospital, but rather several distinct strains. The importance, as well as the difficulties in controlling the spread of MRSA strains in the present conditions of high prevalence, are highlighted.

Bacteriophage Typing↗
PubMedDate not supplied

[Antimicrobial susceptibility of Streptococcus pyogenes, Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis from community acquired respiratory infections in 2000].

The Viriato Study is a nationwide, multicenter prospective study of the antimicrobial susceptibility of bacterial pathogens commonly associated with community-acquired respiratory tract infections in Portugal. In 2000, 28 laboratories participated in the study with a total of 1071 strains, with testing undertaken in a central laboratory. Of the 213 Streptococcus pyogenes strains isolated from patients with acute tonsillitis, all were susceptible to penicillin, amoxicillin/clavulanate and cefuroxime, but 21.1% were resistant to erythromycin, clarithromycin, azithromycin and 16.4% to tetracycline. From patients with lower respiratory tract infection, 403 strains of Haemophilus influenzae, 366 of Streptococcus pneumoniae and 89 of Moraxella catarrhalis were studied. 13.1% of H. influenzae and 94.4% of M. catarrhalis produced beta-lactamase. Among S. pneumoniae isolates, 25.1% were resistant to penicillin (8.8% showing high-level resistance), 14.5% to tetracycline, 12.8% to erythromycin, clarithromycin and azithromycin, and 10.1% to cefuroxime. Overall, penicillin was the most active antimicrobial against S. pyogenes and amoxycillin/clavulanate the most active in vitro simultaneously against H. influenzae, S. pneumoniae and M. catarrhalis isolated from patients with community-acquired LRTI in Portugal.

Community-Acquired Infections↗
PubMedDate not supplied

[Non ulcer dyspepsia, endoscopic gastritis and Helicobacter pylori].

We studied 33 patients with non ulcer dyspepsia and endoscopic gastritis. 21 were female (63.4%) and 12 male (36.4%). Helicobacter pylori (HP) was investigated by gastric mucosal biopsy. Urease test, Gram, culture, and histology were performed in all and two or more of these test hat to be positive to consider HP infection. 16/33 resulted HP positive (48.8%). Erosive gastritis was most commonly associated with H.P. infection (62.5%). This was statistically significant. In all the cases HP positive chronic gastritis was present. 15/16 were active chronic gastritis. Our results suggest that erosive gastritis is most frequently associated with HP infection and non ulcer dyspepsia.

Adolescent↗
PubMedDate not supplied

[Nonulcerative dyspepsia associated with Helicobacter pylori].

30 patients with non ulcer dyspepsia (NUD) were evaluated to find out if there was a relationship with Helicobacter pylori (HP) infection. Gastric biopsies from the antrum were taken and two of them sent to pathology to be stained with H&E and Warthin-Starry. The other three were sent to Microbiology, for urease-test, culture and frotis with Gram stain. To diagnose HP was necessary to get it at least in two of the performed test. This was possible in 20 (66.66%). Chronic active gastritis was observed in 15/20 (75%) and in the 3/10 HP negative patients none had histological alteration shown. Normal aspect of gastric mucosa did not predict Helicobacter pylori infection. The presence of the bacteria could not be correlated to any kind of symptoms and always was associated with chronic gastritis.

Adolescent↗
PubMedDate not supplied

[The recurrence of duodenal ulcer after treatment for Helicobacter pylori. A randomized, double-blind, placebo-controlled study].

We studied 63 duodenal ulcer (DU) patients (p) diagnosed by upper gastrointestinal endoscopy (UGE) and Helicobacter pylori positive (HP). Patients were randomized, double-blinded to receive placebo (PG) 30p or Amoxicillin plus Metronidazole 33p (TG). All of them took Famotidine for six weeks and at this point UGE was performed. DU healing was similar in both groups. HP eradication was possible in 14/24p of TG and 4/23 of PG (58.33% vs 17.39%) difference was statistically significant. DU recurrence at 3 months was 68.75% in PG vs 11.76% in TG (p = 0.001). At the end point of the study global recurrence of DU was 3/24p in TG vs 19/23 in PG (p = 0.000001). Our findings suggest that DU recurrence is related to the presence of HP. Definitive treatment to permanently eradicate the bacteria is to be evaluated.

Adolescent↗
PubMedDate not supplied

[Retrograde endoscopic cholangiopancreatography. Incidence of bacteremia].

ERCP like all the endoscopic procedures, implies some risks of complications, between them, infections. Bacteremia may occur in any endoscopic and gastrointestinal procedure. The rate on ERCP is about 0 to 5.6%. In the present investigation we intended to determine the rate of bacteremia produced by ERCP, the organism that cause bacteremia and to correlate ductal pathology, stasis and bacteremia. From May to October 1988, at the Hospital Vargas of Caracas, 22 ERCP were performed in patients that were included for analysis. Haemocultives were taken for aerobics and anaerobics, gems before ERCP, immediately after the cannulation of biliary and/or pancreatic ducts and 5 minutes later after concluding the study. A high incidence of bacteremia was reported, 13.6%, all the previous haemocultives were negative. The positive haemocultives were during the cannulation procedure and no haemocultive after the study was positive. The organism isolate were Peptococcus sacharoliticcus and Staphylococcus epidermidis both of the normal flora of small intestine and the last one on the skin too. There were not relation between the ductal pathology, stasis and bacteremia. Some organisms were related to nosocomial agents, we considered though the disinfection and polishment of the accessories and equipment adequate. It is recommendable to use prophylactic antibiotic in immunosuppressed patients with valvular prosthesis.

Adult↗
PubMedDate not supplied

[Frequency of Campylobacter pylori in apparently healthy and asymptomatic Venezuelans].

We evaluated 21 healthy asymptomatic Venezuelan volunteers free of risk factors for gastritis with upper gastrointestinal endoscopy, and four antral biopsies: a)2 for histological examinations, b) Urease test, c) culture and gram coloration. 13 out of 21 subjects were positive for Campylobacter pylori (61.30%) all of them had chronic gastritis and in the negative cases 7 were considered histologically normal. Urease test was positive in 12/13 with a sensitivity of 92% and 100% specificity. Frequency in our series is high for Campylobacter pylori (61.30%) and this justify prospective and massive study of the population to detect de prevalence in our country with simpler and cheaper methods.

Adult↗
PubMedDate not supplied

[Changes in the natural history of peptic ulcer after Helicobacter pylori eradication. Randomized, double-blind, placebo controlled trial. Follow-up of 44 months].

We included 63 patients (p) with duodenal ulcer and Helicobacter pylori infection to be treated with Famotidine 40mg/day for six weeks. In the first ten days one group of 33p (TG) received Metronidazole 250mg plus Amoxicillin 500mg T.I.D and 30p (PG) placebo. Helicobacter pylori was eradicated in 62.5% of TG. Infection was always associated with ulcer recurrence. Healing was similar in both groups but recurrence was statistically significant after three month in PG and in the first year all Pg had relapsed. At 44 month only 25% of TG relapsed. The natural history of peptic ulcer disease was changed with Helicobacter pylori eradication.

Adolescent↗
PubMedDate not supplied

[Helicobacter pylori eradication heals the duodenal ulcer. Randomized, simple, and controlled study with omeprazole].

60 patients with Helicobacter pylori (Hp) infection and duodenal ulcer (DU) were randomized to received either: I) Two weeks of bismuth subcitrate, metronidazole and amoxicillin (TG) or II) Omeprazole for four weeks (OG). Endoscopy and antral biopsies were done at entry and four weeks after treatment, control endoscopy was performed 2-4-8 and 12 weeks after inclusion in the trial. Healing was similar in both groups at two four weeks. At twelve weeks DU recurred in OG 65% vs 13.36% in TG and Hp infection was present. Our results showed that Hp eradication healed DU in a similar rate than Omeprazole providing further evidence of a causal link between Hp infection and duodenal ulcer.

Administration, Oral↗
PubMedDate not supplied

[Immunoenzymatic assay for serodiagnosis of Helicobacter pylori infections].

Enzyme-linked immunosorbent assays (ELISA) have been developed to diagnose H. pylori infection. However, the methods are not standardized. We therefore evaluated the sensitivity of ELISA developed in our laboratory in a study population comprising 38 patients with dyspeptic symptoms and 41 healthy children under 10 years. The assays for immunoglobulin G used a pool of sonicated isolates of H. pylori from five patients with dyspeptic symptoms. Serum levels IgG antibodies to cell sonicates of H. pylori were significantly higher (p < 0.001) in patients with positive culture than in the control group. Cutoff score of 0.231 for positive results was determined with mean + 3ds of the healthy group analyzed. On the basis of this survey, we conclude that a serum dilution of 1:300 and 5 micrograms/ml of antigen, are the optimal condition for rapid screening with high sensitivity of 92% of symptomatic patients for the presence of H. pylori.

Antigens, Bacterial↗
PubMedDate not supplied

[Evaluation of methods for the diagnosis of Helicobacter pylori infection].

UNLABELLED: Helicobacter pylori is a gram negative curved bacillus recognized as etiologic agent of chronic gastritis and an important factor in the development of duodenal ulcer and gastric cancer. The purpose of this work is to evaluate three microbiologic methods for diagnosing H. pylori infection. We studied 375 samples from 218 patients, who consulted at the Department of Gastroenterology of the Hospital Vargas and were candidates for endoscopy. Samples of gastric mucous tissue were taken at level of the antrum and each sample was stained with Gram, tested for urease and cultured. RESULTS: whit H. pylori positive 123 patients with duodenal ulcer at the endoscopy (91.1%), 17 had gastric ulcer (76.5%), 40 gastritis and/or duodenitis (60.0%), 1 duodenal ulcer and gastric (100.0%) and 37 normal endoscopies (56.8%). Evaluating the three methods used we found that of the 286 H. pylori positive samples, the Gram stain detected 282 (sensibility 98.6% and specificity 96.6%); the urease test 276 (sensibility 96.5% and specificity 98.6%) and culture was positive in 255 samples (sensibility 89.2% and specificity 100.0%). These results show that both the Gram stain and Urease test are useful for diagnosing H. pylori infection due to their high sensitivity and specificity, rapidness, low cost for the Gram stain, and easy interpretation for Urease test. Culture, even though less sensitivity++, represents the most unquestionable diagnosis and permits carrying out susceptibility to antimicrobials tests.

Helicobacter Infections↗