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G Royo

Publications and source records attributed to G Royo.

At least 19 recordsLinked to original sources
PubMed2000

Application of four molecular techniques for typing outbreak-associated Mycobacterium tuberculosis strains.

We applied four molecular techniques for the typing of strains of Mycobacterium tuberculosis associated with outbreaks: RFLP of the IS6110 insertion sequence, spoligotyping, RAPD, and PCR-IS6110. All 4 techniques were applied to 18 strains which were shown by epidemiological data to be involved in 6 outbreaks. All the methods classified the strains into the same groups as the classical epidemiological data did, but RFLP of the IS6110 insertion sequence and spoligotyping are laborious techniques requiring more than a full day's work, whilst RAPD and PCR IS6110 are simple methods easily incorporated into the daily routine. Nevertheless, a large-scale process of standardization and evaluation is necessary in order to be able to establish the true value of the latter two methods as intraspecific characterization markers for M. tuberculosis isolates.

Bacterial Typing Techniques↗
PubMed2000

[Extra-intestinal infections caused by non-typhi Salmonella serotypes. 9 yrs' experience].

BACKGROUND: The most characteristic finding in non typhoid Salmonella serotype infection is acute gastroenteritis which is usually benign and self-limiting. However, more serious extraintestinal findings, such as bacteraemia and focal infections localized to any organ may appear. PATIENTS AND METHODS: The objective of this article is to describe the most important characteristics of the extraintestinal infections due to non typhoid Salmonella serotypes observed in our hospital between December 1991 and August 1999. To do so, we reviewed the clinical histories of patients in which extraintestinal non typhoid Salmonella serotypes was isolated, applying a clinicomicrobiological protocol. RESULTS: Salmonella enterica was isolated on 1,543 occasions, of which 25 (1.6%) were Salmonella serotype Typhi and 1,518 (98.3%) non typhoid serotypes. Of the patients with non typhoid serotypes infections, 27 had extraintestinal infection (1.8%). The most frequently isolated was the serotype typhimurium (50% of cases) followed by enteritidis (26% of cases) and hadar (7.1% of cases). Regarding the clinical picture, bacteraemias secondary to gastroenteritis and focal infections occurred with the same frequency (35.7%); the remaining were primary bacteraemias. Eight patients were under 10 years of age and 15 patients were over 60. In 57.1% of the patients there was underlying disease. CONCLUSIONS: Extraintestinal non typhoid Salmonella serotypes infections make up 1.8% of all salmonellosis and most of them occur in childhood or in the elderly. Transitory bacteraemias in the context of acute gastroenteritis occur mainly in children. The greatest risk of acquiring focal infections is associated with the existence of underlying illness or immunodepression.

Adolescent↗
PubMed2000

[Mycobacterium chelonae and solitary rectal ulcer].

Solitary rectal ulcer is of varied etiology and the appearance of this syndrome due to Mycobacterium chelonae is exceptional. We present a case of a solitary rectal ulcer associated with Mycobacterium chelonae subspecies chelonae in an immunocompetent individual. This microorganism is involved in cutaneous, ocular, pulmonary and soft tissue infections. Treatment of infections has traditionally been surgical, although various antibiotic treatments have been used depending on the sensitivity of the microorganism, the severity of the infection and the surgical possibilities.

Adolescent↗
PubMed1999

[Evolution of resistance to quinolones in Salmonella enterica in our setting].

Salmonella enterica is mainly associated with acute gastroenteritis; however, it is also associated with other more severe disease processes, for which quinolones are the treatment of choice. We retrospectively studied the evolution of resistance to nalidixic acid and ciprofloxacin of all the clinical isolates of S. enterica from 1992 to 1998 in our hospital environment. A total of 848 strains from feces, blood and other locations were studied. We detected an increase in the resistance to nalidixic acid from 12% in 1992 to 21.3% in 1998, especially in the Enteritidis and Hadar serotypes. We did not detect resistance to ciprofloxacin, but there was in increase in the MIC in the nalidixic acid-resistant strains. Although this is interpreted as sensitive according the the NCCLS criteria, if we apply the cutoff points established by MENSURA, 89.46% of the strains do not fit into this category (S <0.12 mg/l). This puts into question the utility of quinolones in the long-term treatment of severe disease processes produced by this type of strain.

Anti-Infective Agents↗
PubMed1999

[Evolution of resistance to quinolonesin Salmonella enterica in our environment]

Salmonella enterica is mainly associated with acute gastroenteritis; however, it is also associated with other more severe disease processes, for which quinolones are the treatment of choice. We retrospectively studied the evolution of resistance to nalidixic acid and ciprofloxacin of all the clinical isolates of S. enterica from 1992 to 1998 in our hospital environment. A total of 848 strains from feces, blood and other locations were studied. We detected an increase in the resistance to nalidixic acid from 12% in 1992 to 21.3% in 1998, especially in the Enteritidis and Hadar serotypes. We did not detect resistance to ciprofloxacin, but there was in increase in the MIC in the nalidixic acid-resistant strains. Although this is interpreted as sensitive according the the NCCLS criteria, if we apply the cutoff points established by MENSURA, 89.46% of the strains do not fit into this category (S <0.12 mg/l). This puts into question the utility of quinolones in the long-term treatment of severe disease processes produced by this type of strain.

Journal Article↗
PubMed1997

Evaluation of different techniques in the diagnosis of Toxoplasma encephalitis.

This study evaluated the detection of antibodies, circulating antigens and parasite DNA by polymerase chain reaction (PCR) in the diagnosis of toxoplasma encephalitis. The detection of antibody classes and IgG avidity were not useful diagnostically. The detection of circulating antigens by the ELISA system described was not sufficiently sensitive. The detection of DNA by PCR was the most useful test especially in untreated patients, with a sensitivity of 62% overall, 81% in untreated patients and only 20% in treated patients. The use of non-isotopic probes makes the use of this technique feasible in routine diagnostic parasitology laboratories.

AIDS-Related Opportunistic Infections↗
PubMed1997

Comparison of two different PCR detection methods. Application to the diagnosis of pulmonary tuberculosis.

The objectives are to assess the influence of the detection of the amplified DNA fragment on the sensitivity and specificity of the polymerase chain reaction (PCR). One hundred seventy-five sputum samples from 123 patients were processed. Sixty samples were taken from 60 subjects without tuberculosis, and the rest were taken from subjects with tuberculosis confirmed by culture. A fragment of the IS6110 sequence of Mycobacterium tuberculosis, which was detected using two different methods, was amplified. The detection methods used were a digoxigenin-labeled specific probe and chemiluminescent development and reamplification (nested PCR) combined with agarose gel electrophoresis. Sensitivity with probe detection was 75.65% and specificity 100%. Using the nested PCR technique, sensitivity rose to 93.04%, but specificity decreased to 96.6%. PCR is a quick and adequate way to diagnose pulmonary tuberculosis in cases where staining is negative yet there is a clinical suspicion of tuberculosis, even though a standardization process and large scale evaluation are still needed to determine its true usefulness.

DNA Transposable Elements↗
PubMed1997

[Detection of Mycobacterium tuberculosis in sputum using PCR and chemoluminescent display].

BACKGROUND: Polymerase chain reaction (PCR) using a probe with revealed chemoluminescence applied to the rapid diagnosis of pulmonary tuberculosis was used to detect Mycobacterium tuberculosis in sputum samples. METHODS: The sputum samples were treated with proteinase K, SDS, NaOH and CTAB. A fragment of the IS6110 sequence of Mycobacterium tuberculosis detected by a probe marked with digoxigenin and revealed chemoluminescence was amplified. RESULTS: The detection limit of the technique was situated at 10 mycobacteria per sample. Of 120 samples with a positive culture, 88 were positive by chemoluminescence probe (73.3%). The sensitivity decreased to 68.6% (35/51) in samples with negative staining and positive culture. CONCLUSIONS: The application of molecular biology techniques are a good diagnostic alternative in samples with negative staining and clinical suspicion of tuberculosis. Our system is a cheaper alternative than the commercial systems and is applicable in laboratories unable to use radioactive isotopes.

Bacteriological Techniques↗
PubMed1996

[Toxoplasmosis in pregnancy: new diagnostic techniques].

BACKGROUND: The diagnosis of primoinfection by Toxoplasma gondii in immunocompetent patients is not always easy because detectable levels of IgM are found in serum for months or even years. METHODS: We studied the prevalence of T. gondii antibodies in pregnant women and the usefulness of several commercial IgM and IgA detection systems as well as IgG avidity for the diagnosis of primoinfection by T. gondii. We also developed an IgA detection system in our laboratory and studied antigenic determiners recognized by various immunoglobulins by means of Western blot patterns. RESULTS: The prevalence of antibodies in our environment is 56.70% and the incidence of primoinfection in pregnant women is 0.056%. In cases of primoinfection by T. gondii demonstrated by antibody seroconversion, we obtain positive results with all the systems tested. However, when seroconversion does not occur, we continue to get positive results in many cases with some of the technique tested. Nevertheless, there is a higher degree of correlation between the study of IgG avidity and IgA detection and seroconversion. With the Western blot technique, we can see that each type of immunoglobulin recognizes a different antigenic pattern, with antigen 31 kD being recognized by three types of immunoglobulins. CONCLUSION: In spite of the high incidence of antibodies for Toxoplasma gondii in our medium, the incidence of primoinfection during pregnancy is low. As regards the evaluation of the different serological tests, except for seroconversion, none of the serological methods that we tested can independently diagnose primoinfection by T. gondii, even though IgG avidity studies and IgA produce the best results.

Animals↗
PubMed1993

[Enteric fever caused by multiresistant Salmonella typhi: 2 autochthonous cases].

BACKGROUND: References about isolation of strains of Salmonella typhi multiply resistant to antimicrobials and native from Spain are very scant. We describe here two cases of typhoid fever produced by two identical strains of Salmonella typhi. Both strains are multiresistant and autochthonous, judging from epidemiological investigations. METHOD: Microbiological diagnosis was made by means of isolation of causative microorganism from blood and stool, in the first case, and only from stool, in the second one. Antimicrobial susceptibility was ascertained using a minimal inhibitory concentration micromethod. RESULTS: Identification of Salmonella enterica ser. typhi and determination of its resistance to many antimicrobials. Native origin of both strains verified by means of epidemiological investigation. Healing achieved in both cases with ciprofloxacin. CONCLUSIONS: We stand out the rarity of isolating native multiresistant strains of Salmonella typhi in our country, as well as the great epidemiological interest of our finding. We think that diagnosis of these diseases must be made by culturing suitable specimens and isolating causal microorganisms, what will us to determine antimicrobial susceptibility. Finally, we emphasize the resolution of the illness with ciprofloxacin. We consider that this third generation quinolone is a suitable alternative in these cases.

Adult↗
PubMed1991

[Antibodies against Helicobacter pylori in gastroenterology personnel, patients and the healthy population].

We have studied the prevalence of IgG antibodies to H. pylori in gastroenterology personnel, patients and healthy blood donors to determinate if there is a presumable high risk of infection among the first group, frequently at risk of exposure to gastrointestinal secretions. The positive percentage of sera in the gastroenterology personnel was 30.4% and in the healthy control group (mean age 35.8 years) was 38.5% (p = 0.620). In the patient group, the rate of positive results was 90% and in their control group (mean age 58 years) was 78.1% (p = 0.269). However, the differences were statistically significant when groups of different ages were compared (p less than 0.001). The results obtained suggest that the variations in the antibodies levels are age related and do not confirm the presumably increased risk among the gastroenterology personnel.

Adult↗