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J Reina

Publications and source records attributed to J Reina.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Infection by Staphylococcus lugdunensis: clinico-microbiologic characterization of 25 cases].

INTRODUCTION: S. lugdunensis is a recently described staphylococcal species with morphologic characteristic similar to those of S. aureus. It has been associated to a variety of clinical infections. In this paper we present the clinical and microbiological features of S. lugdunensis isolates from 25 patients. MATERIALS AND METHODS: We have studied the S. lugdunensis isolates obtained from clinical specimens in our laboratory over a three-year period, 1994-96. For all isolates we determined the presence of clumping factor, Dnase, free coagulase in tube and ornithine decarboxylase (ODC). Full identification was performed with API ID32-Staph strips (bioMérieux) and antimicrobial susceptibility with commercial broth microdilution MIC panels (PASCO System, Difco). RESULTS: We obtained 38 S. lugdunensis isolates from 25 patients. The clinical specimens were: breast exudate/pus (8), blood (5), surgical wound (2), urine (2), nasal exudate (2), peritoneal fluid (1), pleural fluid (1), venous catheter (1), Tenckoff catheter (1), bartholin pus (1), ulcer (1). The isolates were considered clinically significant in 20 patients, whereas those of the remaining 5 patients were considered mere colonizers. All isolates were clumping factor (+), ODC (+), Dnase (-) and free coagulase (-). 16/23 (69.5%) were susceptible to penicillin and only one isolate was methicillin-resistant. CONCLUSIONS: We have isolated S. lugdunensis from a great variety of clinical specimens (blood, sterile body fluids, urine, skin, abscesses and nasal mucosa). It is specially remarkable the association with non-puerperal mastitis. The presence of clumping factor in all isolates can easily lead to misidentification as S. aureus. The ODC test appears as a good screening method for detecting S. lugdunensis. S. lugdunensis shows a good susceptibility to betalactamic an other antimicrobial agents.

Adult↗
PubMed1998

'Interfacial affinity chromatography' of lipases: separation of different fractions by selective adsorption on supports activated with hydrophobic groups.

Lipases contained in commercial samples of lipase extracts from Rhizopus niveus (RNL) and Candida rugosa (CRL) have been selectively adsorbed on hydrophobic supports at very low ionic strength. Under these conditions, adsorption of other proteins (including some esterases) is almost negligible. More interestingly, these lipases could be separated in several active fractions as a function of a different rate or a different intensity of adsorption on supports activated with different hydrophobic groups (butyl-, phenyl- and octyl-agarose). Thus, although RNL seemed to be a homogeneous sample by SDS-PAGE, it could be separated, via sequential adsorption on the different supports, into three different fractions with very different thermal stability and substrate specificity. For example, one fraction hydrolyzed more rapidly ethyl acetate than ethyl butyrate, while another hydrolyzed the acetate ester 7-fold slower than the butyrate. Similar results were obtained with samples of CRL. Again, we could obtain three different fractions showing very different properties. For example, enantioselectivity for the hydrolysis of (R,S) 2-hydroxy-4-phenylbutanoic acid ethyl ester ranged from 1.2 to 12 for different CRL fractions. It seems that very slight structural differences may promote a quite different interfacial adsorption of lipases on hydrophobic supports as well as a quite different catalytic behavior. In this way, this new 'interfacial affinity chromatography' seems to be very suitable for an easy separation of such slightly different lipase forms.

Adsorption↗
PubMed1998

[Virologic analysis of 1,000 blood samples processed for cytomegalovirus isolation (viremia) and pp65 antigenemia in immunodepressed patients].

BACKGROUND: To study the principal virological aspects of 1,000 blood samples processed for cytomegalovirus (CMV) isolation (viremia) and pp65 antigenemia assay in immunosuppressed patients, and to compare the diagnostic efficacy of both technics. PATIENTS AND METHODS: All the blood samples collected with EDTA, were fraccionated by dextran sedimentation. The polymorfonuclear rich fraction was used for the isolation of CMV by the shell-vial cell culture and the pp65 antigenemia assay. The cell cultures were stained at 18-24 hours with a monoclonal antibody against p72 CMV antigen. RESULTS: The 1,000 blood samples studied belonged to 363 patients (299 infected by the HIV, 49 renal transplant recipients, and 15 patients with haematologic diseases). 78 patients (21.4%) developed a CMV infection and/or disease. The overall results obtained in the comparative study for the CMV detection in peripheral blood were 86.7% for the antigenemia assay and 58.5% for the shell-vial culture (p = 0.0001). Of 49 patients with renal transplant, 20 (40.8%) presented with a CMV infection versus 19.3% in the HIV-positive group. The transplant recipient patients presented most frequently positivity for both diagnostic technics, and the HIV-positive patients a higher percentage of antigenemia-positive with culture negative. The shell-vial culture (viremia) had most diagnostic efficacy in the transplant recipients group. CONCLUSIONS: In the immunosuppressed patients the pp65 antigenemia assay has demonstrated a high diagnostic efficacy for CMV detection in peripheral blood. However because the antigenemia not always correlates with a replicative viral load, it is necessary to routinely perform culture of the blood in a cell culture system, preferently by the shell-vial method, because this system allows to make the diagnosis of CMV infection in a short period of time.

Antigens, Viral↗
PubMed1998

Shell-vial culture and pp65 antigenemia assay in the detection of cytomegalovirus in the first blood sample of renal transplant recipients.

The aim of the study was to compare the efficacy of pp65 antigenemia assay and the shell-vial culture (SVC; viremia) for the diagnosis of cytomegalovirus (CMV) infection in renal transplant recipients, comparing the results obtained in the first blood sample and the total number of blood samples analyzed in this group of patients. During the study period, 70 renal transplant recipients were studied: 44 (62.8%) with CMV infection. The method of sedimentation in a dextran solution for leukocyte extraction was used in the pp65 antigenemia assay. The MRC-5 shell-vial assay was used for CMV isolation from leukocytes (viremia). Eighty blood samples were examined from 70 renal transplant recipients: Of the 44 positive samples studied, in 77.5% of cases, both the antigenemia assay and the SVC were positive. In 16.2%, only the antigenemia assay was positive, and, in 6.2%, only the SVC was positive. In all blood samples studied, the antigenemia was present in 93.7% of cases, and the SVC was present in 83.7% (P = 0.04). If the results obtained in only the first blood sample taken for the diagnosis are studied, then we observe that the antigenemia assay was positive in 39 patients (88.6%), whereas the SVC was positive in 41 patients (93.1%), although the difference was not statistically significant (P = 0.39). It is concluded that the inoculation of all of the leukocytes extracted from blood samples in the SVC seems to produce a slight increase in the sensitivity of the cell culture and that the SVC becomes positive before the antigenemia for the detection of CMV in peripheral blood, especially in the first blood sample.

Antibodies, Monoclonal↗
PubMed1998

An increase in the number of polymorphonuclear leukocytes inoculated on shell-vial culture increases the sensitivity of this assay in the detection of cytomegalovirus in the blood of immunocompromised patients.

A prospective study was conducted comparing the sensitivity of the pp65 antigenemia assay (AGA) to that of the shell-vial culture (SVC) inoculated with increasing quantities of polymorphonuclear leukocytes (PMNLs) in the detection of cytomegalovirus (CMV) in peripheral blood. From the cellular suspension, three SVCs were inoculated with 200,000, 400,000, and 800,000 PMNLs, respectively. Of the 201 patients studied, 67 (31.9%) had positive results in one of the two analytic tests (AGA or SVC). In this group, 13 (19.4%) presented a negative AGA assay; 13 (19.4%) an AGA of 1; 13 (19.4%) an AGA of between 2 and 5; and 28 (41.8%) an AGA with a value > 6 PMNL-positive x 100,000 PMNLs. The SVC inoculated with 200,000 PMNLs detected the presence of CMV in 42 cases (62.6%); 55 (82%) with 400,000; and 64 (95.5%) with 800,000. Statistically significant differences were observed between the isolation capacities of the SVC inoculated with 200,000 and 400,000, and the SVC inoculated with 800,000 PMNLs (p = 0.0001). In the comparison of the overall sensitivity of the AGA with that of the SVC with 200,000, the AGA was found to be significantly more sensitive (p = 0.0052). When comparing with the SVC with 400,000 PMNLs, the two techniques were found to be equally sensitive; and in the comparison with the SVC with 800,000, the culture displayed a greater detection sensitivity (p = 0.0023). According to these results, it seems evident that the increase in the absolute number of PMNLs inoculated in the SVC leads to a significant increase in the sensitivity of the SVC in the detection of low-level viremia by CMV.

Cytomegalovirus↗
PubMed1997

Determination of the number of blood samples needed for optimal detection of cytomegalovirus viremia in immunocompromised patients using a shell-vial assay.

To establish the number of blood samples necessary for the diagnosis of viremic episodes caused by cytomegalovirus (CMV), a prospective analysis was conducted of 238 patients (38 renal transplant recipients and 200 HIV-infected patients) who developed CMV viremia. The usefulness of samples and the volume of blood required to demonstrate the presence of viremia by CMV was also studied. The first blood sample was diagnostic for CMV viremia in 53.3% of the viremic patients; the second sample documented an additional 22.2% of cases of viremia (75.5% of infected patients); and the third sample demonstrated viremia in the remaining 24.5%. Thus, a diagnosis of CMV viremia was established in every patient (100% of episodes of viremia). In this study, the use of three 3 ml blood samples collected at 24 h intervals was sufficient to detect all episodes of CMV viremia in patients clinically suspected to have disseminated disease.

Cytomegalovirus Infections↗
PubMed1997

Evaluation of a direct immunofluorescence cytospin assay for the detection of herpes simplex virus in clinical samples.

A comparison between a direct immunofluorescence assay (DFA) and the shell-vial culture (SVC) was conducted to evaluate their efficacies according to the quality and origin of the sample and the type of herpes simplex (HSV) responsible for the infection. The SVC detected all 58 HSV-infected samples, while the DFA detected only 49 (84.5%) positive samples. The DFA detected HSV type 1 in 22 of 89 samples (24.7%) and HSV type 2 in 27 of 96 samples (28.1%). Compared with the SVC, the DFA had a sensitivity of 75.8% for HSV type 1 and 93.1% for HSV type 2. The sensitivity of the DFA depends on the quality of the sample. Thus, while DFA is recommendable as a screening method, the SVC remains the method of choice for obtaining the maximum diagnostic yield from the sample.

Female↗
PubMed1997

Comparison of Madin-Darby canine kidney cells (MDCK) with a green monkey continuous cell line (Vero) and human lung embryonated cells (MRC-5) in the isolation of influenza A virus from nasopharyngeal aspirates by shell vial culture.

We report a comparative study of the MDCK, Vero, and MRC-5 cell lines in the isolation of the influenza A (IA) virus. We studied 746 samples in which 63 IA viruses were isolated. The MDCK line displayed 100% sensitivity, the Vero line displayed 71.4%, and the MRC-5 displayed 57.1%. The MDCK line showed a statistically significant difference with respect to the Vero line (P = 0.001) and the MRC-5 line (P = 0.001). The quantitative sensitivity analysis showed the MDCK line to be superior to the other lines. It seems that the MDCK line is still one of the most recommendable for the isolation of the IA virus from respiratory samples.

Animals↗
PubMed1997

[Comparison between the LLC-MK2 and MDCK cell lines in the isolation of parainfluenza virus from nasopharyngeal aspirates].

BACKGROUND: We report a prospective comparative study of the efficacy of three commercial cell lines in the isolation of the parainfluenza (PI) virus from nasopharyngeal samples. MATERIAL AND METHODS: In a 16 months period we studied all nasopharyngeal samples from patients with the suspension of a viral respiratory infection. The compared cell lines were LLC-MK2 and MDCK. All samples were processed by the shell-vial assay, incubated 3 days at 36 degrees C. The monolayers were stained by an indirect immunofluorescence assay with a monoclonal antibody against the nucleoprotein of the PI virus. RESULTS: In the study period 746 samples were analyzed, 46 PI virus were isolated, all belonged to the serotype 3. The LLC-MK2 cell line isolated 44 viruses (95.6%) and the MDCK cell line 41 (89.1%), no statistically significant differences were detected (p = 0.14) (qualitative sensitivity). In 84.8% of positive samples, the PI virus was isolated simultaneously in the two cell lines. Neither cell line isolated all PI virus. No statistical differences were detected in the quantitative sensitivity, although the LLC-MK2 cell line detected a slightly more samples with a low viral load (70.4 vs 68.2%). CONCLUSIONS: In view of the results obtained in this study, we believe that anyone of the two cell lines would be used in the isolation of the PI virus from respiratory samples.

Cell Line↗