Are GES carbapenemases underdiagnosed? An allelic discrimination assay for their accurate detection and differentiation

GES (Guiana Extended Spectrum) carbapenemases belong to "minor class A carbapenemases" and its prevalence could be underestimated due to the lack of specific tests. The aim of this study was to develop an easy PCR method to differentiate between GES β-lactamases with or without carbapenemase activity, based on an allelic discrimination system of SNPs that encode E104K and G170S mutations, without need of sequencing. Two pair of primers and Affinity Plus probes, labeled with different fluorophores; FAM/IBFQ and YAK/IBFQ, were designed for each one of the SNPs. This allelic discrimination assay allows to detect in real time the presence of all type of GES- β-lactamases, being able to differentiate between carbapenemases and extended-spectrum β-lactamase (ESBL), through a quick PCR test that avoid costly sequencing approaches and could help to decrease the current underdiagnosis of minor carbapenemases that scape of phenotypic screenings.

Associations of serum sclerostin levels with body composition, pulmonary function, and exacerbations in COPD patients

BACKGROUND

In COPD, the bronchial epithelium shows a pathologically activated Wnt pathway. Sclerostin (SOST) is a secreted glycoprotein that is associated with bone metabolism and blocks the Wnt pathway. We hypothesized that low sclerostin levels might be associated with lung function and COPD exacerbations in patients.

METHODS

We studied 139 outpatients with stable COPD and normal kidney function. We assessed the serum levels of SOST and bone metabolism parameters, body composition, clinical characteristics and lung function at baseline. We followed the patients prospectively for 12 months after enrolment. Moderate exacerbations and hospital admissions were recorded during follow-up.

RESULTS

The serum SOST levels were 23.98±7.6 pmol/l (men: 25.5±7.7 pmol/l, women: 20.3±5.9 pmol/l (p < 0.001)). SOST showed correlations with age (r = 0.36), FFMI (r = 0.38), FEV1 (r = 0.27), DLCO (r = 0.39), 6MWD (r = 0.19) and CAT (r = -0.24). In multivariate linear regression analysis, only age (beta=0.264) and FFMI (beta=1.241) remained significant. SOST showed a significant negative correlation with serum phosphorus (r = -0.29). Cox proportional risk analysis indicated that patients in the lower tertile of SOST levels were at higher risk of moderate COPD exacerbation (HR 2.015, CI95% 1.136-3.577, p = 0.017) and hospital admission due to COPD (HR 5.142, CI95% 1.380-19.158, p = 0.015) than the rest of the patients.

CONCLUSIONS

SOST levels are associated with body composition and lung function in patients with COPD. Furthermore, lower SOST levels predict a higher risk of exacerbations and hospitalization.

Description of Influenza B in seasonal epidemic in Cantabria during the beginning of the pandemia due to SARS-CoV-2

Introduction. Co-circulation of the two Influenza B lineages hinders forecast of strain to include in trivalent vaccine. Autonomous Communities such as Cantabria continue without supplying tetravalent vaccine. The aim of this study was to analyse epidemiological characteristics of influenza type B in Cantabria (2019-2020 season) as well as to establish the predominant lineage and its relation to the recommended vaccine. Methods. Retrospective study whereby flu diagnosis and lineage analysis were determined by RT-PCR. Results. All samples belonged to the Victoria lineage. Most prevalent viral co-infection was due to SARS-CoV-2. The population affected by influenza B was mainly paediatric and non-vaccinated patients more frequently required hospital admittance. Conclusions. Influenza type B has a higher incidence in the paediatric population and type A affects more the adult population. Only 28.8% of patients with Influenza B that presented with some underlying condition or risk factor were vaccinated. This shows the need to increase coverage with tetravalent vaccines in order to reduce the burden of disease associated with the Influenza B virus.

Autochthonous cutaneous leishmaniasis in urban domestic animals (Felis catus / Canis lupus familiaris) from central-western Venezuela

Leishmaniasis is a zoonotic disease caused by intracellular protozoa of the Leishmania genus that are spread and transmitted by sandflies. Natural infection and clinical disease in domestic cats and dogs appear to be rare or perhaps largely under-reported in endemic areas. However, previous reports on infected domestic animals usually implicate the same Leishmania species that affect humans in tropical and subtropical areas of the world suggesting a potential role for zoonotic transmission. In the present study we assessed a representative sample of cats and dogs from endemic urban / suburban areas of Lara state in central western Venezuela. In both dogs and cats, cutaneous disease exhibits a spectrum of manifestations that range from single papules or nodules, which may evolve into ulcerative, plaque-like or scaly lesions. Cytochrome b (cyt b) PCR gene sequence analysis revealed L. mexicana as the causative agent in all cases, including two human cases proceeding from the same study area at the same time the study was carried out. In order to improve our understanding on feline/canine infection with Leishmania mexicana, and address potential zoonotic concerns it is necessary to characterize its enzootic reservoirs and vectors as well as the possible anthropophilic players linking to the peridomestic and domestic cycles.

Post-traumatic endophthalmitis caused by Nocardia nova

Introduction

Nocardia nova complex has been associated with infections in both immunocompetent and immunocompromised patients. Infection can be localized or disseminated, affecting skin and soft tissues, the respiratory system, bones and joints, the circulatory system and especially the central nervous system. Ocular infections such as keratitis, scleritis, conjunctivitis, dacryocystitis, orbital cellulitis and endophthalmitis due to Nocardia spp. are infrequently reported, and usually described after penetrating corneal trauma or ocular contact with plants and soils.

Case presentation

An immunocompetent male presented with a history of penetrating ocular trauma that had evolved to infectious endophthalmitis, which was refractory to different antibiotic treatments. No micro-organisms were isolated from repeated conjunctival smear and corneal scraping cultures between the ocular trauma (August 2014) and the endophthalmitis diagnosis (November 2015). After this period, N. nova sensu stricto was isolated in aqueous humour aspirate. Treatment was adjusted and clinical improvement was obtained after an adequate microbiological procedure, including an optimal sampling and an antimicrobial-susceptibility testing report.

Conclusion

Nocardia identification to the species level and performance of antimicrobial-susceptibility tests are both essential tools for treatment adjustment and clinical improvement.

Stable and Broad Spectrum Cross-Protection Against Pepino Mosaic Virus Attained by Mixed Infection

While recent pepino mosaic virus (PepMV; species Pepino mosaic virus, genus Potexvirus, family Alphaflexiviridae) epidemics seem to be predominantly caused by isolates of the CH2 strain, PepMV epidemics in intensive tomato crops in Spain are caused by both CH2 and EU isolates that co-circulate, representing a challenge in terms of control, including cross-protection. In this work, we hypothesized that mixed infections with two mild isolates of the EU and CH2 strains (PepMV-Sp13 and -PS5, respectively) may be useful in PepMV cross-protection in Spanish epidemics, providing protection against a broad range of aggressive isolates. Thus, we performed a range of field trials and an experimental evolution assay to determine the phenotypic and genetic stability of PepMV-Sp13 and -PS5 mixed infections, as well as their cross-protective efficiency. Our results showed that: (i) the phenotype of PepMV-Sp13 and -PS5 mixed infections was mild and did not change significantly when infecting different tomato cultivars or under different environmental conditions in Spain, (ii) PepMV-Sp13 and -PS5 mixed infections provided more efficient protection against two aggressive EU and CH2 isolates than single infections, and (iii) PepMV-Sp13 and -PS5, either in single or in mixed infections, were less variable than other two PepMV isolates occurring naturally in PepMV epidemics in Spain.

Characterization of Begomoviruses Sampled during Severe Epidemics in Tomato Cultivars Carrying the Ty-1 Gene

Tomato yellow leaf curl virus (TYLCV, genus Begomovirus, family Geminiviridae) is a major species that causes a tomato disease for which resistant tomato hybrids (mainly carriers of the Ty-1/Ty-3 gene) are being used widely. We have characterized begomoviruses severely affecting resistant tomato crops in Southeast Spain. Circular DNA was prepared from samples by rolling circle amplification, and sequenced by massive sequencing (2015) or cloning and Sanger sequencing (2016). Thus, 23 complete sequences were determined, all belonging to the TYLCV Israel strain (TYLCV-IL). Massive sequencing also revealed the absence of other geminiviral and beta-satellite sequences. A phylogenetic analysis showed that the Spanish isolates belonged to two groups, one related to early TYLCV-IL isolates in the area (Group 1), and another (Group 2) closely related to El Jadida (Morocco) isolates, suggesting a recent introduction. The most parsimonious evolutionary scenario suggested that the TYLCV isolates of Group 2 are back recombinant isolates derived from TYLCV-IS76, a recombinant virus currently predominating in Moroccan epidemics. Thus, an infectious Group 2 clone (TYLCV-Mu15) was constructed and used in in planta competition assays against TYLCV-IS76. TYLCV-Mu15 predominated in single infections, whereas TYLCV-IS76 did so in mixed infections, providing credibility to a scenario of co-occurrence of both types of isolates.

Applied diagnostics in liver cancer. Efficient combinations of sorafenib with targeted inhibitors blocking AKT/mTOR

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. There is increasing interest in developing specific markers to serve as predictors of response to sorafenib and to guide targeted therapy. Using a sequencing platform designed to study somatic mutations in a selection of 112 genes (HepatoExome), we aimed to characterize lesions from HCC patients and cell lines, and to use the data to study the biological and mechanistic effects of case-specific targeted therapies used alone or in combination with sorafenib. We characterized 331 HCC cases in silico and 32 paired samples obtained prospectively from primary tumors of HCC patients. Each case was analyzed in a time compatible with the requirements of the clinic (within 15 days). In 53% of the discovery cohort cases, we detected unique mutational signatures, with up to 34% of them carrying mutated genes with the potential to guide therapy. In a panel of HCC cell lines, each characterized by a specific mutational signature, sorafenib elicited heterogeneous mechanistic and biological responses, whereas targeted therapy provoked the robust inhibition of cell proliferation and DNA synthesis along with the blockage of AKT/mTOR signaling. The combination of sorafenib with targeted therapies exhibited synergistic anti-HCC biological activity concomitantly with highly effective inhibition of MAPK and AKT/mTOR signaling. Thus, somatic mutations may lead to identify case-specific mechanisms of disease in HCC lesions arising from multiple etiologies. Moreover, targeted therapies guided by molecular characterization, used alone or in combination with sorafenib, can effectively block important HCC disease mechanisms.

Sternal wound infection caused by Gordonia bronchialis: identification by MALDI-TOF MS

INTRODUCTION

Gordonia spp. infections are uncommon. However, a few clinical cases have been reported in the literature, particularly those involving immunocompromised hosts. Advanced microbiology diagnosis techniques, such as matrix-assisted laser desorption ionization-time of flight MS (MALDI-TOF MS), have been recently introduced in clinical microbiology laboratories in order to improve microbial identification, resulting in better patient management.

CASE PRESENTATION

Here, we present a new clinical case of persistent wound infection caused by Gordonia bronchialis in a 64-year-old woman after a mitral valve replacement, using two MALDI-TOF-based systems for identifying this micro-organism.

CONCLUSION

Both MALDI-TOF systems were able to identify Gordonia spp.; thus, providing a useful tool that overcomes the current limitations of phenotypic identification associated with this micro-organism. Although the technique validation deserves additional verification, our study provides guidance about MALDI-TOF as a fast and easy method for Gordonia spp. identification.

Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding

The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus-based vector (clbvINpr-AtFT and clbvINpr-CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4-6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr-AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes.

Microbiological and clinical aspects of respiratory infections associated with Bordetella bronchiseptica

Bordetella bronchiseptica is a well-known veterinary pathogen, but its implication in human disease is probably not fully recognized. The purpose of this study was to determine the clinical significance of 36 B. bronchiseptica isolates from respiratory samples of 22 patients. Therefore, we describe microbiological characteristics, including phenotypic and genotypic identification as well as antimicrobial susceptibilities of the isolates. Clonal relatedness was evaluated using pulsed-field gel electrophoresis (PFGE). Most of the patients had some underlying immunosuppressive condition. Eighteen out of 22 (82%) patients had respiratory symptoms, and the death of 2 patients was associated with respiratory infection.All strains were correctly identified at species level by the simultaneous use of phenotypic methods and were confirmed by specific amplification of the upstream region of the fla gene. Tigecycline, minocycline, doxycycline, colistin, and meropenem were the most active agents tested. PFGE analysis revealed that repeated infections involving each patient had been caused by the same strain.

Citrus leaf blotch virus invades meristematic regions in Nicotiana benthamiana and citrus

To invade systemically host plants, viruses need to replicate in the infected cells, spread to neighbouring cells through plasmodesmata and move to distal parts of the plant via sieve tubes to start new infection foci. To monitor the infection of Nicotiana benthamiana plants by Citrus leaf blotch virus (CLBV), leaves were agroinoculated with an infectious cDNA clone of the CLBV genomic RNA expressing green fluorescent protein (GFP) under the transcriptional control of a duplicate promoter of the coat protein subgenomic RNA. Fluorescent spots first appeared in agroinfiltrated leaves 11-12 days after infiltration, indicating CLBV replication. Then, after entering the phloem vascular system, CLBV was unloaded in the upper parts of the plant and invaded all tissues, including flower organs and meristems. GFP fluorescence was not visible in citrus plants infected with CLBV-GFP. Therefore, to detect CLBV in meristematic regions, Mexican lime (Citrus aurantifolia) plants were graft inoculated with CLBV, with Citrus tristeza virus (CTV), a virus readily eliminated by shoot-tip grafting in vitro, or with both simultaneously. Although CLBV was detected by hybridization and real-time reverse transcription-polymerase chain reaction (RT-PCR) in 0.2-mm shoot tips in all CLBV-inoculated plants, CTV was not detected. These results explain the difficulty in eliminating CLBV by shoot-tip grafting in vitro.

Development of viral vectors based on Citrus leaf blotch virus to express foreign proteins or analyze gene function in citrus plants

Viral vectors have been used to express foreign proteins in plants or to silence endogenous genes. This methodology could be appropriate for citrus plants that have long juvenile periods and adult plants that are difficult to transform. We developed viral vectors based on Citrus leaf blotch virus (CLBV) by duplicating a minimum promoter (92 bp) either at the 3' untranslated region (clbv3'pr vector) or at the intergenic region between the movement and coat protein (CP) genes (clbvINpr vector). The duplicated fragment (-42/+50) around the transcription start site of the CP subgenomic RNA (sgRNA) had the full promoter activity and induced synthesis of a new sgRNA in infected plants. Agroinoculation with these vectors resulted in systemic infection of Nicotiana benthamiana and the resulting virions systemically infected citrus plants. A clbvINpr vector carrying the green fluorescent protein (GFP) gene expressed GFP in citrus plants and triggered gfp silencing in gfp-transgenic citrus plants, and vectors carrying fragments of the phytoene desaturase or the magnesium chelatase genes incited a silencing phenotype in citrus plants. These silenced phenotypes persisted in successive flushes. Because CLBV infections are symptomless in most citrus species, the effective silencing induced by CLBV-derived vectors will be helpful to analyze citrus gene function.

Prevalence and molecular epidemiology of acquired AmpC β-lactamases and carbapenemases in Enterobacteriaceae isolates from 35 hospitals in Spain

The purpose of this investigation was to determine the prevalence of plasmid-mediated AmpC (pAmpC) and carbapenemases in Enterobacteriaceae collected from 35 hospitals in Spain and to establish their epidemiological relationships. We conducted a prospective multi-centre study on pAmpC- or carbapenemase-producing Enterobacteriaceae isolates from clinical samples collected from February to July 2009. The strains suspected to carry pAmpC were resistant or showed intermediate susceptibility to co-amoxiclav and second- or third-generation cephalosporins. Strains suspected to carry a carbapenemase were selected because they showed a minimum inhibitory concentration (MIC) to imipenem >1 mg/L. Polymerase chain reaction (PCR) and a sequencing strategy were used to characterise the enzymes. The clonal relationships between isolates was analysed by pulsed field gel electrophoresis (PFGE). Among 100,132 Enterobacteriaceae isolates collected, 1,654 were compatible with the production of pAmpC or carbapenemases. We found a prevalence of 0.64 % of pAmpC (n = 635) and 0.04 % of carbapenemases (n = 43). The most prevalent pAmpC enzymes were CMY-type (78.3 %), DHA-type (19.5 %), ACC-type (1.6 %) and FOX-type (0.6 %). The CMY-type was the most frequent in Escherichia coli and Proteus mirabilis species, whereas the DHA-type was mainly found in Klebsiella spp. The enzymes involved in carbapenem resistance were VIM-1, IMP-22 and the new IMP-28. Nine new bla genes were described: bla (CMY-54), bla (CMY-55), bla (CMY-56), bla (CMY-57), bla (CMY-96), bla (DHA-6), bla (DHA-7), bla (FOX-8) and bla (IMP-28). The prevalence of pAmpC or carbapenemases found is not negligible. The CMY-types were the predominant pAmpC, whereas the VIM or IMP enzymes were the predominant carbapenemases. Furthermore, we observed a great genetic diversity among pAmpC-producing strains and a close clonal relationship between carbapenemase-producing strains.

Relationship between functional capacity and quality of life in heart transplant patients

The goal of heart transplantation (HT) is not only to prolong the life of patients with end-stage heart failure, but also to offer them the sort of health they enjoyed before the disease. It is widely known that patients' functional capacity improves after HT but what about their quality of life (QoL)? Do functional capacity and QoL improve simultaneously? In the present study, we compared the progression of effort capacity and QoL in the first 2 years after HT. A prospective longitudinal study was performed in 58 heart transplant recipients (43 males, 15 females, age 51.6 ± 10 years) able to complete an effort test 2, 6, 12, and 24 months after transplantation. The studied variables included the five dimensions of the Euroqol-5D questionnaire (EQ-5D) test: mobility, self-care, daily activities, pain/discomfort, anxiety, and depression; a visual analog scale from 0 to 100; and the results (metabolic equivalent units [METs] and time of exercise) of the effort test at 2, 6, 12, and 24 months after transplantation. Analysis of variance was used to compare these variables at each point. Significance was set at P < .05. Functional capacity, measured by both METs and time of exercise, improved progressively (METs: 2 months: 5.2 ± 1.8, 6 months: 6.6 ± 2.1, 12 months: 7.5 ± 2.2, and 24 months: 8.5 ± 2.3, P < .001). As well, the result of EQ-5D questionare improved in parallel to exercise capacity. However, visual analog scale score did not change significatively during the follow-up (2 months: 78.9.3 ± 16.1, 6 months: 83.8 ± 11.3, 12 months: 83.3 ± 11.1, 24 months: 85.2 ± 14.9; P = .192), reaching a plateau at 6 to 24 months. In conclusion, the improvement in functional capacity shown by heart transplant recipients in the first 2 years after transplantation was not parallel to the feelings of well-being measured by the analog scale of the EQ-5D. Possibly long after transplantation patients will compare themselves to healthy people rather than to their state before HT, resulting in improvements the visual analog scale.

Colonisation and infection due to Enterobacteriaceae producing plasmid-mediated AmpC β-lactamases

OBJECTIVES

To investigate the epidemiology and clinical features of infections caused by Enterobacteria producing plasmid-mediated AmpC β-lactamases (pAmpC), which are emerging as a cause of resistance to extended-spectrum cephalosporins.

METHODS

A prospective multicentre cohort of patients with infection/colonisation due to pAmpC-producing Enterobacteriaceae was performed in 7 Spanish hospitals from February throughout July 2009. pAmpCs were characterised by PCR and sequencing.

RESULTS

140 patients were included; organisms isolated were Escherichia coli (n = 100), Proteus mirabilis (n = 20), Klebsiella pneumoniae (n = 17), and others (n = 3). Overall, 90% had a chronic underlying condition. The acquisition was nosocomial in 43%, healthcare-associated in 41% (14% of those were nursing home residents), and community in 16%. Only 5% of patients had no predisposing feature for infection with multidrug-resistant bacteria. Nineteen percent of patients were bacteraemic. Inappropriate empirical therapy was administered to 81% of bacteraemic patients, who had a crude mortality rate of 48%. The most frequent enzyme was CMY-2 (70%, predominantly in E. coli and P. mirabilis) followed by DHA-1 (19%, predominantly in K. pneumoniae).

CONCLUSION

pAmpC-producing Enterobacteriaceae caused nosocomial, healthcare-associated and community infections mainly in predisposed patients. Invasive infections were associated with high mortality which might be partly related to inappropriate empirical therapy.

Can we accept donors who have suffered a resuscitated cardiac arrest?

INTRODUCTION AND AIMS

The shortage of donor organs has prompted increased acceptance of hearts from donors with more comorbidities. With increasing frequency, hearts are being offered from patients who have undergone a resuscitated cardiac arrest (RCA). Our aim was to compare the rate of complications in the postoperative and follow-up periods, depending on whether the transplanted organ came from a donor who had undergone an RCA.

MATERIALS AND METHODS

We included all 604 heart transplantations (HTs) performed in our center from 1987 to 2009, including 25 recipients who received an organ from a donor who had undergone RCA. We considered RCA to be an in-hospital cardiac arrest that was resuscitated from the onset, with a duration of <30 minutes, and with total recovery of cardiac and hemodynamic function. We analyzed ischemia time, incidence of acute graft failure (AGF), intubation period, recovery room stay, and long-term survival. The statistical methods were Student t and chi-square tests.

RESULTS

There were no differences in baseline characteristics, except that patients in the RCA group were younger (47±13 vs 51±11 years; P=.50). There were also no differences between the RCA group and the other patients in ischemia time (151±50 vs 154±53 minutes; P=.826), incidence of AGF (33% vs 24.7%; P=.311), hours of intubation (76±204 vs 72±249; P=.926), days of recovery room stay (6±7 vs 8±6; P=.453), or survival after HT (53±54 vs 53±52 months; P=.982).

CONCLUSIONS

Patients receiving a heart from a patient with an in-hospital RCA and subsequent hemodynamic stability have a similar outcomes to other HT patients.

Post-heart transplant tumors: chronology and impact on survival

INTRODUCTION AND AIMS

Tumors are the second leading cause of death beyond the first year heart transplantation (HT). The aim of our study was to establish a chronology for the occurrence and the impact on overall survival of de novo neoplasms after HT.

MATERIALS AND METHODS

We included 597 patients undergoing HT from January 1987 to December 2008. De novo tumors were classified into groups: Kaposi's sarcoma, melanoma, epidermoid skin carcinoma, other skin tumors, lung neoplasms, bladder tumors, prostate adenocarcinoma, digestive tumors, lymphomas, and other tumors. We based the study on the median value and interquartile range of the tumors to estimate their occurrence. Survival rates were calculated using Kaplan-Meier curves and the log-rank tests. We included only patients with survivals beyond 1 year after HT.

RESULTS

A total of 109 tumors developed during the follow-up. There were no differences in the survival of patients who lived more than 1 year regarding the development or not of a tumor (155±8 vs 179±6 months; P=.177).

CONCLUSIONS

The incidence of tumor occurrence after HT was high (18.25%). There were several periods in which the occurrence of certain tumors was more frequent, while other periods appeared to be tumor-free. As most tumors were skin cancers, their impact on overall survival was low.

Identification of atypical Rhodococcus-like clinical isolates as Dietzia spp. by 16S rRNA gene sequencing

Rhodococcus equi and Dietzia spp. are closely related actinomycetes that show similar phenotypic properties. In humans, R. equi is an opportunistic pathogen associated with severe immunodeficiency. Dietzia spp. are environmental bacteria that have been isolated recently from clinical material and are presumptively associated with human infections. During the last 5 years, 15 bacterial isolates from human clinical samples collected at the Hospital Marqués de Valdecilla, Santander, Spain, were identified as R. equi by the API Coryne test. 16S rRNA gene sequencing confirmed seven isolates to be true R. equi strains, whereas the other eight were identified as members of the genus Dietzia, including Dietzia maris (four isolates), Dietzia natronolimnaea (two isolates), and Dietzia timorensis and Dietzia sp. (one isolate each). The eight Dietzia isolates were highly sensitive to 12 antimicrobial compounds.

What is the best biomarker for diagnosis of rejection in heart transplantation?

INTRODUCTION

Acute cellular rejection is a major cause of graft loss in heart transplantation (HT). Endomyocardial biopsy remains the gold standard for its diagnosis, but it is an invasive procedure not without risk. A proinflammatory state exists in rejection that could be assessed by determining plasma levels of inflammatory biomarkers.

OBJECTIVE

To analyze the utility of various inflammatory markers, which is most important and what values best classify patients to diagnose rejection.

MATERIALS AND METHODS

A prospective study in 123 consecutive cardiac transplant recipients was conducted from January 2002 to December 2006. Fibrinogen protein (Fgp) and function (Fgf), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and sialic acid (SA) determinations were performed at one, two, four, six, nine, and 12 months post-HT at the same time as biopsies. Coronary arteriography and intravascular ultrasound were performed on the first and last follow-up visits. Heart-lung transplants, retransplants, pediatric transplants, patients who died in the first month, and patients who refused consent were excluded. Also excluded were determinations that coincided with renal dysfunction, active infection, hemodynamic instability, or a non-evaluable biopsy. The final analysis included 79 patients and 294 determinations. The correlation between the levels of these biomarkers and the presence of rejection in the biopsy (> or = ISHLT grade 3) was studied.

RESULTS

We did not find significant differences in the values of any of the markers analyzed on the six follow-up visits. Only CRP showed significant and sustained differences between the two groups (with and without rejection) from the second follow-up visit (month 2). The area under the curve showed significant differences in Fgp (0.614, p = 0.013), Fgf (0.585, p = 0.05), TNF-alpha (0.605, p = 0.02), SA (0.637, p = 0.002) and mainly CRP (0.765, p = 0.0001). CRP levels below 0.87 mg/dL ruled out rejection with a specificity of 90%.

CONCLUSIONS

Among the inflammatory markers analyzed, CRP was the most useful parameter for non-invasive screening of acute cellular rejection in the first year post-HT.

Tolerance profile of the proliferation signal inhibitors everolimus and sirolimus in heart transplantation

INTRODUCTION

The side effects of proliferation signal inhibitors (PSIs) have been characterized as a class. However, it would be convenient to assess them according to the molecule.

OBJECTIVE

To assess prospectively the tolerance of PSIs among heart transplant (HT) patients.

PATIENTS AND METHODS

We studied 56 HT patients who sequentially received PSIs to either withdraw (77%) or reduce the dosage of a calcineurin inhibitor; 42 received everolimus (EVE) and 14 sirolimus (SRL). We analyzed the demographic variables, side effects, and need to withdraw the drug during a median follow-up period of 365 days.

RESULTS

No differences between groups were observed upon analysis of the clinical and demographic variables when the treatment was changed owing to renal dysfunction (67%) or tumor (32%). No difference between groups was observed over the follow-up period (P = .28). Infection was the most common side effect, 28.6%: EVE, 14.3% versus SRL, 71.4% (P < .0001). Edema occurred in 26.8% of patients: EVE, 14.3% versus SRL, 64.3% (P = .001); diarrhea in 5.4% of patients: EVE, 2.4% versus SRL, 14.3% (P = .15). Treatment was withdrawn in 23.2% of the patients due to intolerance: EVE, 11.9% versus SRL, 57.1% (P < .0001). EVE showed significantly better survival without edema or infections or used for drug withdrawal upon Kaplan-Meier analysis, (P = .01; P = .0005; P = .0097). Only SRL use was shown to be an independent predictor of side effects.

CONCLUSION

Edema and infections are the main problems caused by PSIs. EVE may display a better tolerance profile than SRL.

Correlation between beta-adrenoceptors and G-protein-coupled receptor kinases in pretransplantation heart failure

INTRODUCTION

Prolonged catecholamine overstimulation of the myocardium in chronic heart failure causes a reduction in the number and functionality of beta1-adrenoceptors (beta1-AR) of the heart. Desensitization of beta1-AR is mediated by their phosphorylation by a group of cytosolic kinases (G-protein-coupled receptor kinases GRK). In advanced heart failure, an increase in GRK levels associated with the severity of the disease has been observed.

OBJECTIVE

The objective of this study was to analyze messenger RNA (mRNA) levels of beta1-AR in the myocardium of patients who underwent transplantation for advanced heart failure and their correlation with expression of the major cardiac isoenzymes of GRK.

MATERIALS AND METHODS

Myocardial tissue samples were obtained from the left ventricles of 14 explanted hearts of patients who underwent transplantation for dilated (n = 7) and ischemic (n = 7) cardiomyopathy. RT-PCR techniques were used to analyze mRNA levels of beta1-AR and the isoenzymes GRK2, GRK3, and GRK5.

RESULTS

We observed a significant correlation between beta1-AR and the 3 subtypes of GRK (R(2) = 0.668, 0.71, and 0.318, respectively).

CONCLUSIONS

In patients with advanced heart failure pretransplantation, we observed a significant correlation between beta1-AR and GRK2 and GRK3 levels. GRK5, the subtype predominantly expressed in the myocardium, showed a lesser correlation with beta1-AR levels.

Randomized prospective study of the evolution of renal function depending on the anticalcineurin used

BACKGROUND

Renal failure is one of the primary medium- to long-term morbidities in heart transplant (HT) recipients. To a great extent, this renal deterioration is associated with calcineurin inhibitors, primarily cyclosporine A (CsA). It has been suggested that tacrolimus provides better renal function in these patients. We assessed the medium-term evolution of renal function depending on the calcineurin inhibitor used after HT.

PATIENTS AND METHOD

We assessed 40 consecutive HT recipients over one year. Patients were randomized to receive CsA (n = 20) or tacrolimus (n = 20) in combination with mycophenolate mofetil (1 g/12 h) and deflazacort in decreasing dosages. We analyzed demographic variables before HT, creatinine values before and six months after HT and incidence of acute rejection.

RESULTS

No demographic, clinical, or analytical differences were observed were between the two groups before HT. Repeated measures analysis of variance of creatinine values showed no significant differences between the two groups (P = .98). Furthermore, no differences were observed in either the incidence of rejection (P = .02) or rejection-free survival (P = .14).

CONCLUSION

There seems to be no difference in efficacy profile and renal tolerability between CsA and tacrolimus therapy during the first months after HT.

Clinical variables associated with the presence of inflammatory infiltrates in patients with dilated cardiomyopathy undergoing heart transplantation

INTRODUCTION

Idiopathic dilated cardiomyopathy (DCM) is, together with ischemic heart disease, the major cause of end-stage heart failure leading to heart transplantation. However, an unknown percentage of patients with this diagnosis has inflammatory foci found in the histopathological study of the explanted heart. This fact suggests an undetected process of acute myocarditis as the cause of cardiac dysfunction.

OBJECTIVE

The objective of this study was to identify clinical and echocardiographic variables related to the presence of myocardial infiltrates, as a potential guide to determine which patients should undergo endomyocardial biopsy in DCM.

MATERIALS AND METHODS

We retrospectively analyzed 161 patients who underwent heart transplantation with a diagnosis of DCM between 1987 and 2007. The presence of inflammatory infiltrates was considered significant when the histopathological study of tissue blocks from the left ventricle showed 1 or more foci per cm(2) of perivascular or interstitial mononuclear or polymorphonuclear cells, whether or not in the presence of cytolysis.

RESULTS

Seventeen patients (11%) had these inflammatory histological findings; of them, 6 (35%) showed preponderance of eosinophils and 7 (41%) showed areas of cytolysis. The DCM group with inflammatory infiltrates showed significant differences in terms of younger age (45 +/- 15 vs 50 +/- 11 years; P < .01) and smaller ventricular diameters (P < .05). Male gender was more frequent in this group, and the patients had a poorer clinical status and greater dependence on inotropic drugs.

CONCLUSIONS

Inflammatory infiltrates are frequently present in DCM explanted hearts. Although there are no relevant clinical variables to identify subclinical myocarditis, these patients are younger and have smaller ventricular diameters and poorer functional status at the time of transplantation.

Pharmacognostical studies of the plant drug Mimosae tenuiflorae cortex

The bark of the Mimosa tenuiflora (Willd.) Poiret (Leguminoseae) tree, known as tepescohuite in Mexico, is commonly used in this country and in Central America to elaborate different products for the treatment of skin burns and lesions. The cicatrizing properties of extracts obtained from this bark have been scientifically studied, attributing the main biological activity to its tannin and saponin content. Studies include clinical trials of phytodrugs based on Mimosae tenuiflora bark extracts for treatment of venous leg ulcerations. Recent commercialization of the plant drug Mimosae tenuiflorae cortex requires pharmacognostical information to develop quality-control methods for raw materials and extracts produced with this plant drug. The present paper reports a group of ethnobotanical, morphological, chemical, and molecular studies performed with Mimosae tenuiflora materials obtained by collection in the southeastern Mexican state of Chiapas. Macro- and micro-morphological parameters were established to authenticate the genuine drug that allowed detection of adulterants usually found in commercial samples of this plant material. These morphological characteristics can be used for rapid identification of the drug and are particularly useful in the case of powdered materials. The chemical studies performed demonstrated that tannins represent the major component group in the bark. Its content in genuine tepescohuite is 16% and is mainly composed of proanthocyanidins, a condition permitting a tannin-based chemical-control method for fingerprinting the plant drug. Contrariwise, the saponin concentration in Mimosae tenuiflora bark is extremely low, and its isolation and content evaluation represent a complex procedure that is unsuitable for routine control purposes. Finally, random amplified DNA (RAPD) analysis results a useful tool for obtaining DNA specific markers of Mimosae tenuiflora species which should be useful in future studies involving raw material authentication by molecular methods.

mTOR Inhibitors and Their Secondary Effects in Cardiac Trasplant Recipients: A Descriptive Study

BACKGROUND

Mammalian target of rapamycin (mTOR) inhibitors are relatively new drugs in the field of cardiac transplantation (HT), hence the need for further study of their secondary effects. We described the nature and incidence of secondary effects of these drugs in a group of HT recipients.

PATIENTS AND METHODS

We studied 23 HT recipients aged 52 +/- 9 years (Male: 91%, body mass index: 27 +/- 3.7, ischemic cardiopathy: 52%, dilated cardiomyopathy: 39%) who were started on an mTOR inhibitor (everolimus: 65%, sirolimus: 35%) as part of their treatment. We have described the secondary effects detected during a follow-up period of 10.7 +/- 6 months.

RESULTS

The reasons for starting the drug were renal impairment (65%), tumors (26%), and others (8%). During follow-up, 17% of patients required a dose reduction and 12% required drug withdrawal: edemas: 4%, recurrent infection: 4%, and hemolytic-uremic syndrome: 4%. Drug-attributable edemas presented in 26% of patients. Thirty nine percent suffered an infection that required hospital admission, 89% of which were lung and all bacterial two patients died due to the infection). The mean time to first infection was 5 +/- 6 months. In patients who had a treatment change due to tumors, 50% experienced improvement. We did not detect alterations in cholesterol, triglycerides, creatinine, or leukocytes. There was a nonsignificant trend toward decreased hemoglobin and platelet levels (P = .07 and P = .056, respectively).

CONCLUSIONS

Lung infection was the principal complication among our patients treated with mTOR inhibitors. A large percentage required dose reduction (17%) and even drug withdrawal (12%) due to secondary effects.

Impact of Smoking on Survival After Heart Transplantation

INTRODUCTION

Smoking is an important risk factor in any population group. According to previous studies, having been a smoker before heart transplantation (HT) confers a greater likelihood of developing any type of tumor or other complication after HT. Our objective was to determine the impact of having been a smoker before HT on survival, respiratory complications during the postoperative period, and long-term tumor development.

MATERIALS AND METHODS

After excluding combined transplantations, pediatric transplantations, and retransplantations, we retrospectively reviewed 288 HT performed between November 1987 and September 2006. We divided patients into nonsmokers (including those who quit smoking more than 1 year before HT (n = 163), exsmokers for less than 1 year (n = 76), and those who smoked until HT (n = 49). The statistical tests were chi-square, Student t, analysis of variance (ANOVA), and Kaplan-Meier curves.

RESULTS

There were more male patients among smokers and exsmokers than nonsmokers (93.9% vs 96.1% vs 82%, respectively; P = .003). There were no differences in baseline characteristics between the groups. Exsmokers remained intubated for a longer time than smokers or nonsmokers (33.4 +/- 44.6 vs 14.2 +/- 7.3 vs 17.9 +/- 19.2, respectively; P = .05). We observed the same trend in recovery unit stay (7.9 +/- 10.5 days vs 4.4 +/- 1.88 days vs 4.84 +/- 3.49 days, respectively; P = .021). The development of any type of tumor was also more frequent among smokers and exsmokers, although not significantly. The survival rate was similar in nonsmokers and exsmokers, although higher than in smokers (89.57 vs 92.11% vs 81.63%, respectively; P = .031). We did not observe differences in the causes of death.

CONCLUSIONS

Patients who smoke or have smoked until shortly before HT showed a poorer prognosis and a longer recovery unit stay. There was also a trend to increased tumor development.

mTOR Inhibitors: Do They Help Preserve Renal Function?

BACKGROUND

Renal function deterioration is one of the main problems facing heart transplant recipients. The mammalian target of rapamycin (mTOR) inhibitors, in combination with or replacing calcineurin inhibitors, may help preserve renal function. The aim of this study was to evaluate the progression of renal function after switching the immunosuppressive regimen.

PATIENTS AND METHODS

We studied 23 heart transplant recipients (5.5 +/- 4.5 years since transplantation). An mTOR inhibitor was introduced to replace cyclosporine (everolimus, 65%; sirolimus, 35%). Patient clinical characteristics and renal function were studied after switching. The statistical analysis used Student t test for paired data.

RESULTS

The reason for the transplantation was ischemic cardiopathy (52%), dilated myocardiopathy (39%), or other causes (9%). Mean age at time of transplantation was 52 +/- 9 years. Comorbidities were as follows hypertension (43%), insulin-dependent diabetes (22%), hypercholesterolemia (39%), and ex-smokers (70%). The reason for the switch was increased creatinine (65%), appearance of tumors (26%), or others (8%). Previous creatinine level was 1.89 +/- 0.6 mg/dL with clearance of 61.7 +/- 23 mL/min and at the end of follow-up (mean follow-up, 11 +/- 6 months) creatinine level was 2.0 +/- 1.45 mg/dL with clearance of 68.3 +/- 35 mL/min, namely, no significant difference (P = .49 and P = .57, respectively). In the subgroup of patients who switched treatment due to renal dysfunction, initial creatinine level was 2.38 +/- 0.4 mg/dL with clearance of 42.3 +/- 10 mL/min and at the end of follow-up it was 2.28 +/- 0.2 mg/dL and 43.6 +/- 11 mL/min, respectively (P = .68 for creatinine and clearance).

CONCLUSIONS

The introduction of mTOR inhibitors to the immunosuppressant regimen may be useful to delay renal functional deterioration caused by calcineurin inhibitors.

Differences in Clinical Profile and Survival After Heart Transplantation According to Prior Heart Disease

OBJECTIVE

The objective of this study was to compare baseline characteristics and long-term survival among patients undergoing heart transplantation (HT) according to the 3 main types of prior heart disease: ischemic, idiopathic dilated cardiomyopathy (IDC), and valvular.

MATERIALS AND METHODS

Four hundred twenty-three HTs performed between 1989 and 2005 were included. We excluded pediatric transplantation, retransplantations, combined transplantations (lung and kidney), and transplantations due to heart diseases other than ischemic, IDC, and valvular. Baseline characteristics of the recipients were analyzed, as well as short-term and long- term survival by groups. Analysis of variance (ANOVA) was used for continuous variables and chi-square was used for categorical variables. Survival analysis was computed using Kaplan-Meier curves and the log-rank test, as well as multivariate analysis using logistic regression.

RESULTS

The ischemic and valvular heart disease groups were older and had a more frequent history of prior heart surgery and circulatory support at the time of transplantation compared with the IDC group. The incidence of arterial hypertension and dyslipidemia was higher among ischemic heart disease recipients. Survival rates at 30 days did not show significant differences (ischemic, 88%; IDC, 93%; and valvular; 84%; P = .21). Long-term survival rates were greater in the IDC than in the valvular or ischemic heart disease groups (75% vs 65% and 62%, respectively; P = .021). The multivariate analysis showed an association between the IDC group and long-term survival (odds ratio [OR], 0.55; 95% confidence interval [CI] 0.35-0.89; P = .015).

CONCLUSIONS

(1) Patients showed a different clinical profiles depending on their pretransplantation heart disease. (2) There were no differences in early mortality between the groups. (3) Long-term survival was significantly greater among IDC transplant recipients and similar in ischemic and valvular heart disease transplant recipients.

Clinical and Hemodynamic Profile of Patients With Advanced Heart Failure Considered for Heart Transplantation

INTRODUCTION

The present study evaluated the clinical and hemodynamic situation of patients with advanced heart failure considered for heart transplantation (HT) to examine the possible impact of prior cardiac disease.

METHODS

We analyzed the pretransplant clinical, echocardiographic, and hemodynamic parameters of 422 consecutive HT patients. Pediatric and heart plus lung transplants were excluded, as were retransplantations. The results were compared by dividing the patients into three groups according to the background heart disease that led to HT: ischemic heart disease (IHD), dilated myocardiopathy (DMC), or valvular disease.

RESULTS

Differences were observed in the baseline characteristics according to the type of heart disease. Male gender, hypertension, and diabetes were more frequent among IHD, while DMC patients tended to be younger. There were no differences in the clinical parameters such as liver and kidney function, in the functional class, or in the need for inotropic treatment over the days prior to transplantation. Likewise, no differences were recorded in the hemodynamic parameters, such as pulmonary pressure, pulmonary vascular resistance, or transpulmonary pressure gradient. As regards the echocardiographic parameters, the patients with DMC showed greater ventricular diameters and lesser ejection fractions for both ventricles.

CONCLUSION

No important differences were recorded in the clinical situation or hemodynamic parameters of patients with advanced heart failure accepted for transplantation, according to the background cardiac disease. This observation could be due to the homogenization by strict transplant waiting list inclusion criteria.

Ezetimibe in Heart Transplantation: Initial Experience

Dyslipidemia is a common problem among heart transplant (HT) recipients; it is a frequent risk factor in these patients that is exacerbated by immunosuppressive drugs. Statins are effective drugs to treat dyslipidemia in HT recipients, but control is suboptimal in some patients. Ezetimibe acts through inhibition of the enterohepatic recirculation, a mechanism different from but complementary to statins. Our objective was to assess the effect of the addition of ezetimibe to statin therapy among a population of HT patients.

PATIENTS AND METHODS

We included 19 stable patients on statin therapy with suboptimal control of cholesterol. Determinations were performed at baseline on statins and at 6 months (statins + ezetimibe). The analyzed variables were total cholesterol and fractions, triglycerides, cyclosporine levels, CPK, SGOT/SGPT, and bilirubin. The statistics were Student's t test for paired samples.

RESULTS

The overall mean age was 59 +/- 9 years with 95% males and mean BMI 27.5 +/- 3.5. The time since HT was 7 +/- 3 years. The reason for HT included ischemic heart disease in 68%. Pre-HT risk factors included in arterial hypertension in 32% and insulin-dependent diabetes mellitus in 10%, Dyslipidemia occurred in 68%; hypertriglyceridemia in 16% and hyperuricemia in 21%. Immunosuppression was cyclosporine in 100% and steroids in 94%. Type of lipid-lowering agent was simvastatin in 5%; pravastatin, 32%; atorvastatin, 58%; fibrates, 10%. The ezetimibe dose was 10 mg/day in 95% of cases. When ezetimibe was added we observed differences in total cholesterol values (total cholesterol at baseline: 279 +/- 74, total cholesterol with ezetimibe: 198 +/- 47 mg/dL; P = .0001) and LDL-cholesterol values (LDL-cholesterol at baseline: 171 +/- 69, LDL-cholesterol with ezetimibe: 109 +/- 41 mg/dL; P = .001). The remaining variables did not show significant differences.

CONCLUSION

The addition of ezetimibe to statin therapy among heart transplant patients was effective to control dyslipidemia and showed an excellent safety profile.

Course of Patients With Chronic Hepatitis C Virus Infection Undergoing Heart Transplantation

OBJECTIVE

The objective of this study was to describe the clinical course of patients with chronic hepatitis C virus (HCV) infection undergoing heart transplantation (HT).

MATERIALS AND METHODS

Among 499 patients transplanted in our hospital between January 1989 and September 2006, 11 subjects (2.2%) had chronic HCV infection. We analyzed liver function laboratory parameters pretransplantation as well as at 3, 6, 12 months, and last available, pre- and postsurgical hepatobiliary ultrasounds, and mortality. The mean time since HT was 32 +/- 23 months.

RESULTS

No abnormalities in the liver parenchyma were observed on the ultrasound examinations performed before or after transplantation. There were 3 deaths (27%), none of which was related to HCV infection. Liver function laboratory parameters remained stable during the follow-up.

CONCLUSIONS

The clinical course of patients with chronic HCV infection undergoing HT whose presurgical assessment did not show significant liver damage was favorable. No morphological or laboratory abnormalities were observed that would suggest reactivation of the infection during the follow-up.

Mortality After Heart Transplantation in Adults With Congenital Heart Disease: A Single-Center Experience

The number of congenital heart disease (CHD) patients transplanted to date is small. The results are comparable to those undergoing heart transplantation (HT) for other etiologies. However, advances in pediatric surgery over recent years (eg, the Fontan procedure) has increased the demand for HT by a growing number of children who reach adulthood and who also have a different profile. We analyzed the clinical profile and survival of our CHD patients compared with other etiologies.

MATERIALS AND METHODS

From July 17, 1991 to December 31, 2006, eight HT were performed in our center for CHD. A descriptive study determined the baseline characteristics and survival of these patients, compared with those of the overall transplant group and other subgroups (dilated cardiomyopathy, ischemic heart disease).

RESULTS

Mean age was 26 years. Four (50%) CHD patients were diagnosed with single-ventricle anatomy, associated or not with other lesions; none had been operated with the Fontan procedure. Two patients died prematurely. Early, 1-, and 10-year survival was 75% at each time point. Early, 1-, and 10-year survival in the group with other diagnoses was 90%, 78%, and 60%, respectively, and in the dilated cardiomyopathy group it was 94%, 86%, and 72%, respectively.

CONCLUSION

The current number of CHD transplant patients was small and young. The most common etiology was single-ventricle anatomy without a prior Fontan operation. Overall survival was comparable to HT for dilated cardiomyopathy.

Mortality After Heart-Lung Transplantation Experience in a Reference Center

The 2006 International Society for Heart and Lung Transplantation registry reported that there were differences in mortality after heart-lung transplantation (HLT) depending on the etiology for transplantation. Our objective was to conduct an analysis on mortality after HLT at our center.

MATERIALS AND METHODS

From January 1991 to December 2006, 25 HLT were performed on patients with the following characteristics: mean age of 38 +/- 11 years with 62% males and 4% with previous surgery. The cohort included 17% urgent transplants. The mean ischemia time was 198 +/- 60 minutes. We divided patients into four etiologic groups: congenital heart disease of the Eisenmenger type; primary pulmonary hypertension; chronic obstructive pulmonary disease/emphysema/fibrosis with right ventricular impact; or pulmonary dysfunction with concomitant left ventricular depression. Three patients were excluded from the analysis because they did not fit in any of the groups.

RESULTS

The mean follow-up of the sample was 862 +/- 1290 days. The overall hospital survival as well as that at 1 and 5 years was 59%, 50%, and 37%, respectively. In the Eisemmenger's syndrome cohort no death occurred during hospitalization and survival at 5 years was 50%.

CONCLUSIONS

HLT was a therapeutic option with high mortality. Hospital mortality was high in absolute terms. Congenital heart disease of the Eisenmenger type may be a lower risk group.

Analysis of the Impact of Donor Gender on Early Mortality

INTRODUCTION

Many studies have shown a detrimental effect of female donor gender on heart transplantation (HT) outcome.

OBJECTIVE

We retrospectively evaluated our experience in HT to determine the effect of donor gender on early survival.

MATERIALS AND METHODS

We divided the sample of 464 primary HT from November 1997 to September 2006 into 4 groups: G1, female donor to a male recipient; G2, male donor to a male recipient; G3, male donor to female recipient; and G4, female donor to a female recipient. We performed a descriptive study of the baseline characteristics. The chi(2) test was used to determine differences in early mortality (30 days) between groups and a multivariate analysis to identify confounding factors to increase mortality.

RESULTS

Although the univariate study showed that G1 showed a significantly lower early survival rate (84%) than G2 (91%), the multivariate study adjusted for donor and recipient weight and size, urgency level, previous surgery, and age only showed urgency level (odds ratio [OR] 2.6; 95% confidence interval [CI] 1.2-5.57; P = .016) and previous surgery (OR 5.8; 95% CI 2.7-12.4; P < .01) to be predictors of early mortality. When baseline characteristics were analyzed, we found that 31% of HT in G1 were urgent versus 18% in G2, and 32% of patients in G1 had previous surgery versus 17% in G2.

CONCLUSIONS

Donor gender did not appear to negatively affect early survival. In our series, urgent HT in male recipients with a female was more frequent than with a male donor heart. The higher early mortality in male recipients of an urgent HT from a female than from a male donor was attributable to a higher baseline risk profile.

Characterization of the urease operon of Brucella abortus and assessment of its role in virulence of the bacterium

Most members of the genus Brucella show strong urease activity. However, the role of this enzyme in the pathogenesis of Brucella infections is poorly understood. We isolated several Tn5 insertion mutants deficient in urease activity from Brucella abortus strain 2308. The mutations of most of these mutants mapped to a 5.7-kbp DNA region essential for urease activity. Sequencing of this region, designated ure1, revealed the presence of seven open reading frames corresponding to the urease structural proteins (UreA, UreB, and UreC) and the accessory proteins (UreD, UreE, UreF, and UreG). In addition to the urease genes, another gene (cobT) was identified, and inactivation of this gene affected urease activity in Brucella. Subsequent analysis of the previously described sequences of the genomes of Brucella spp. revealed the presence of a second urease cluster, ure2, in all them. The ure2 locus was apparently inactive in B. abortus 2308. Urease-deficient mutants were used to evaluate the role of urease in Brucella pathogenesis. The urease-producing strains were found to be resistant in vitro to strong acid conditions in the presence of urea, while urease-negative mutants were susceptible to acid treatment. Similarly, the urease-negative mutants were killed more efficiently than the urease-producing strains during transit through the stomach. These results suggested that urease protects brucellae during their passage through the stomach when the bacteria are acquired by the oral route, which is the major route of infection in human brucellosis.

Isolation of Mycoplasma hominis in critically ill patients with pulmonary infections: clinical and microbiological analysis in an intensive care unit

OBJECTIVE

Mycoplasma hominis is a well recognized extragenital pathogen. However, it is an uncommon cause of respiratory infections in critically ill patients admitted to the intensive care unit (ICU).

DESIGN AND SETTING

Prospective clinical investigation in a 21-bed ICU in a university hospital.

PATIENTS

Seven patients requiring intensive care who developed a ICU-acquired pneumonia in which M. hominis was recovered from bronchoalveolar lavage and pleural fluid cultures.

INTERVENTIONS

M. hominis was isolated in all patients by use of conventional bacteriological cultures. All strains were identified by 16S rRNA gene sequencing analysis. Patients' charts were reviewed for each case of infection.

RESULTS

Seven strains of M. hominis were isolated during a 4-year period. All of these isolates were recovered from adult men admitted to the ICU and all had clinical signs of pneumonia. In three patients treatment for M. hominis with quinolones was associated with a good clinical response.

CONCLUSION

Suspicion of M. hominis pneumonia must be heightened particularly in critically ill patients. Therefore an understanding of the microbiology of this organism is essential to successfully treat patients with these infections that are not ordinarily covered with standard antibiotic therapy.

Evolutional Changes in Maintenance Immunosuppression Following Heart Transplantation

Patients with a heart transplant (HT) may require changes in their immunosuppressive maintenance medication. The basic treatment regimen in our patients consisted of an anticalcineurin agent, an antimetabolite, and a steroid.

OBJECTIVE

We undertook a descriptive study to quantify the incidence and causes of these changes and determine how they occur.

MATERIALS AND METHODS

We included the 432 HT performed at our center from November 1987 to October 2005. The baseline treatment was considered to be the treatment given following HT, and the maintenance treatment was that taken at the time of data collection. Kaplan-Meier survival curves were constructed for the analysis.

RESULTS

The most significant change was the switch from azathioprine to mycophenolate mofetil. The survival rate after 17 years was 66%.

CONCLUSIONS

As in the international registries, there has been an evident reduction in the use of cyclosporine and more particularly of azathioprine, in favor of tacrolimus and mycophenolate mofetil, respectively. No changes in the use of steroids have been observed. These data reflect an increasingly greater use of immunosuppressive agents with reduced side effect profiles.