Predicting Fungemia in the ICU: Unveiling the Value of Weekly Fungal Surveillance and Yeast Colonisation Monitoring.

Fungemia remains a major threat in intensive care units (ICUs), with high mortality rates despite advances in diagnostics and treatment. Colonisation by yeasts is an independent risk factor for fungemia; however, its predictive utility requires further research. In this 8-year study, we analysed 38,017 samples from 3206 patients and 171 fungemia episodes as part of a weekly fungal surveillance programme. We evaluated species-specific colonisation patterns, the predictive value of the Colonisation Index (CI) and Corrected Colonisation Index (CCI), and candidemia risks associated with different yeast species and anatomical site colonisation. Our results showed that C. auris, N. glabratus, and C. parapsilosis colonisation increased with longer hospital stays (0.8% to 11.55%, 8.13% to 16.8%, and 1.93% to 5.14%, respectively). The CI and CCI had low discriminatory power (AUROC 67% and 66%). Colonisation by any yeast genera demonstrated high sensitivity (98.32%) and negative predictive value (NPV) (95.90%) but low specificity and positive predictive value (PPV) (23.90% and 6.64%). Tracheal and urine cultures had the highest PPV (15.64% and 12.91%), while inguinal cultures had the highest NPV (98.60%). C. auris (12.32%) and C. parapsilosis (5.5%) were associated with a higher fungemia risk (log-rank < 0.001). These findings support the use of weekly surveillance to better stratify the fungemia risk and optimise antifungal use in ICUs.

First Report of a Fatal Septicaemia Case Caused by Vibrio metoecus: A Comprehensive Functional and Genomic Study.

BACKGROUND: In recent years, we have witnessed an unprecedented increase in the incidence of vibriosis due to global warming. Vibrio metoecus is a recently described V. cholerae-like species that has not been associated with septicemia death in humans. During follow-up of human vibriosis, we received a blood isolate from a patient with secondary septicemia who died a few hours after admission. METHODS: Phenotypic and genotypic methods failed to identify the isolate, which could only be identified by Average Nucleotide Identity after genome sequencing. The isolate was then subjected to a series of in vitro and ex vivo assays, complemented by comparative genomics focused on the identification of unique genetic traits. Strains and genomes from the same and related species (V. cholerae and V. mimicus) were used for analyses. RESULTS: The isolate was the only one able to resist and multiply in human serum. Its genome contained virulence genes shared with V. mimicus and/or V. cholerae, with those associated with sialic acid degradation within pathogenicity island 2 standing out. However, it also presented a unique gene cluster, flanked by a transposase gene, putatively related to surface polysaccharide pseudosialyzation. CONCLUSION: In this study, we document the first case of death from septicemia due to V. metoecus and propose that the acquisition of surface pseudosialyzation genes would explain the ability of certain isolates of this species to survive in blood. Consequently, our discovery underscores the urgent need to monitor and study new emerging pathogenic species, as climate change may be facilitating their spread and increasing the risk of serious infections in humans.

Impact of Long SARS-CoV-2 Omicron Infection on the Health Care Burden: Comparative Case-Control Study Between Omicron and Pre-Omicron Waves.

BACKGROUND: Following the initial acute phase of COVID-19, health care resource use has escalated among individuals with SARS-CoV-2 infection. OBJECTIVE: This study aimed to compare new diagnoses of long COVID and the demand for health services in the general population after the Omicron wave with those observed during the pre-Omicron waves, using similar assessment protocols for both periods and to analyze the influence of vaccination. METHODS: This matched retrospective case-control study included patients of both sexes diagnosed with acute SARS-CoV-2 infection using reverse transcription polymerase chain reaction or antigen tests in the hospital microbiology laboratory during the pandemic period regardless of whether the patients were hospitalized. We included patients of all ages from 2 health care departments that cover 604,000 subjects. The population was stratified into 2 groups, youths (<18 years) and adults (≥18 years). Patients were followed-up for 6 months after SARS-CoV-2 infection. Previous vaccination, new diagnoses, and the use of health care resources were recorded. Patients were compared with controls selected using a prospective score matched for age, sex, and the Charlson index. RESULTS: A total of 41,577 patients with a history of prior COVID-19 infection were included, alongside an equivalent number of controls. This cohort encompassed 33,249 (80%) adults aged ≥18 years and 8328 (20%) youths aged <18 years. Our analysis identified 40 new diagnoses during the observation period. The incidence rate per 100 patients over a 6-month period was 27.2 for vaccinated and 25.1 for unvaccinated adults (P=.09), while among youths, the corresponding rates were 25.7 for vaccinated and 36.7 for unvaccinated individuals (P<.001). Overall, the incidence of new diagnoses was notably higher in patients compared to matched controls. Additionally, vaccinated patients exhibited a reduced incidence of new diagnoses, particularly among women (P<.001) and younger patients (P<.001) irrespective of the number of vaccine doses administered and the duration since the last dose. Furthermore, an increase in the use of health care resources was observed in both adult and youth groups, albeit with lower figures noted in vaccinated individuals. In the comparative analysis between the pre-Omicron and Omicron waves, the incidence of new diagnoses was higher in the former; however, distinct patterns of diagnosis were evident. Specifically, depressed mood (P=.03), anosmia (P=.003), hair loss (P<.001), dyspnea (<0.001), chest pain (P=.04), dysmenorrhea (P<.001), myalgia (P=.011), weakness (P<.001), and tachycardia (P=.015) were more common in the pre-Omicron period. Similarly, health care resource use, encompassing primary care, specialist, and emergency services, was more pronounced in the pre-Omicron wave. CONCLUSIONS: The rise in new diagnoses following SARS-CoV-2 infection warrants attention due to its potential implications for health systems, which may necessitate the allocation of supplementary resources. The absence of vaccination protection presents a challenge to the health care system.

Study of pediatric invasive pneumococcal disease in the 13-pneumococcal conjugated vaccine era.

BACKGROUND: Invasive pneumococcal disease (IPD) remains a significant concern among children under 5, despite vaccination efforts. This study assessed IPD prevalence and associated risks in pediatric population. METHODS: An observational, retrospective, multicenter study in Comunidad Valenciana, Spain, of IPD cases in children under 13 from January 2012 to September 2022. Data from the CV Microbiology Surveillance Network (RedMIVA) and medical records were reviewed. RESULTS: A total of 379 IPD cases in 377 patients were analyzed, predominantly males (54.11 %) under 5 (81.17 %). PCV13 vaccination notably reduced PCV13-serotypes IPD (p=0.0002), except serotype 3. Pneumonia was common, with half having underlying conditions (50.40 %). Worse outcomes occurred in patients with neurological disorders (ANOVA, p=0.57). Vaccine failures often involved underlying conditions (63 %) and serotypes 3 and 19A. Immunodeficiencies may relate to recurrent IPD, but evidence is limited. CONCLUSION: Despite vaccination, IPD still impacts children, influenced by immunological status, affecting severity and mortality.

Evaluating the diagnostic performance of Liaison® chemiluminescence assay as screening tool for detection of acute Epstein-Barr infection: A comparative study.

The present investigation assessed the Liaison® diagnostic performance in detecting Epstein-Barr (EBV) IgM-VCA in a large patient cohort, considering age and symptomatology. VIDAS® were employed as a benchmark for acute EBV infection. The study also probed other coexisting conditions and potential cross-reactivity for error sources. A total of 1311 samples were analyzed, with notable associations found only among paediatric (kappa=0.75) and young adult (kappa=0.58) populations with compatible symptoms. ROC analysis revealed varying optimal cutoff values based on age and symptom categorizations. Logistic regression models identified age and patients from Oncology or Infectious Disease as significant factors for false positives. Potential interferences emerged with RF, ANCA, cytomegalovirus-IgM and VHS-IgM. Notably, Liaison® couldn´t distinguish EBV patients from Oncology, Haemathology or Internal Medicine. This study provides valuable insights, such as implementing ageand symptom-specific thresholds or reviewing test requests, for optimizing EBV serology in microbiology laboratories, leading to faster and more reliable responses.

Role of the first WHO mutation catalogue in the diagnosis of antibiotic resistance in Mycobacterium tuberculosis in the Valencia Region, Spain: a retrospective genomic analysis.

BACKGROUND: In June, 2021, WHO published the most complete catalogue to date of resistance-conferring mutations in Mycobacterium tuberculosis. Here, we aimed to assess the performance of genome-based antimicrobial resistance prediction using the catalogue and its potential for improving diagnostics in a real low-burden setting. METHODS: In this retrospective population-based genomic study M tuberculosis isolates were collected from 25 clinical laboratories in the low-burden setting of the Valencia Region, Spain. Culture-positive tuberculosis cases reported by regional public health authorities between Jan 1, 2014, and Dec 31, 2016, were included. The drug resistance profiles of these isolates were predicted by the genomic identification, via whole-genome sequencing (WGS), of the high-confidence resistance-causing variants included in the catalogue and compared with the phenotype. We determined the minimum inhibitory concentration (MIC) of the isolates with discordant resistance profiles using the resazurin microtitre assay. FINDINGS: WGS was performed on 785 M tuberculosis complex culture-positive isolates, and the WGS resistance prediction sensitivities were: 85·4% (95% CI 70·8-94·4) for isoniazid, 73·3% (44·9-92·2) for rifampicin, 50·0% (21·1-78·9) for ethambutol, and 57·1% (34·0-78·2) for pyrazinamide; all specificities were more than 99·6%. Sensitivity values were lower than previously reported, but the overall pan-susceptibility accuracy was 96·4%. Genotypic analysis revealed that four phenotypically susceptible isolates carried mutations (rpoB Leu430Pro and rpoB Ile491Phe for rifampicin and fabG1 Leu203Leu for isoniazid) known to give borderline resistance in standard phenotypic tests. Additionally, we identified three putative resistance-associated mutations (inhA Ser94Ala, katG Leu48Pro, and katG Gly273Arg for isoniazid) in samples with substantially higher MICs than those of susceptible isolates. Combining both genomic and phenotypic data, in accordance with the WHO diagnostic guidelines, we could detect two new multidrug-resistant cases. Additionally, we detected 11 (1·6%) of 706 isolates to be monoresistant to fluoroquinolone, which had been previously undetected. INTERPRETATION: We showed that the WHO catalogue enables the detection of resistant cases missed in phenotypic testing in a low-burden region, thus allowing for better patient-tailored treatment. We also identified mutations not included in the catalogue, relevant at the local level. Evidence from this study, together with future updates of the catalogue, will probably lead in the future to the partial replacement of culture testing with WGS-based drug susceptibility testing in our setting. FUNDING: European Research Council and the Spanish Ministerio de Ciencia.

Starkeya nomas sp. nov., a prosthecate and budding bacterium isolated from an immunocompromized patient.

Strain HF14-78462T is an environmental bacterium found in clinical samples from an immunocompromized patient in 2014 at Hospital Universitari i Politècnic La Fe (Valencia, Spain). Phenotypically, strain HF14-78462T cells were Gram-stain-negative, aerobic, non-spore forming and non-motile small rods which formed mucous and whitish-translucent colonies when incubated at 20-36 °C. Phylogenetic analyses based on the 16S rRNA genes and the whole genomes of closest sequenced relatives confirmed that strain HF14-78462T is affiliated with the genus Starkeya. The strain was oxidase, catalase and urease positive; but indole, lysine decarboxylase, ornithine decarboxylase and DNase negative, did not produce H2S and was able to utilize a wide variety of carbon sources including acetamide, adonitol, amygdalin, l-arabinose, citric acid, glucose, mannitol and melibiose. Unlike Starkeya novella and Starkeya koreensis, strain HF14-78462T failed to grow in thiosulphate-oxidizing media and had a narrower temperature growth range. Its genome was characterized by a size of 4.83 Mbp and a C+G content of 67.75 mol%. Major fatty acids were C18:1 ω7c, cyclo C19 : 0 and C16 : 0, its polar acids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an aminophospholipid; while the ubiquinones were Q9 (1.8 %) and Q10 (98.2 %). Digital DNA-DNA hybridization values were 41 and 41.4 against S. novella and S. koreensis, respectively, while average nucleotide identity values were around 84 %. Phenotypic, average nucleotide identity and phylogenomic comparative studies suggest that strain HF14-78462T is a new representative of the genus Starkeya and the name Starkeya nomas sp. nov. is proposed. The type strain is HF14-78462T (=CECT 30124T=LMG 31874T).

IgG antibody response to pneumococcal-conjugated vaccine (Prevenar®13) in children with immunodeficiency disorders.

Measurement of anti-pneumococcal capsular polysaccharides (anti-PnPs) IgG titers is an important tool in the immunologic assessment of patients with suspected immunodeficiency disorders (ID) to reduce the morbi-mortality and minimize severe infections. Retrospectively, we studied the relationship among anti-PnPs IgG response to 3 doses of Prevenar®13, levels of immune system components, leukocyte populations, and clinical data in children with ID. Serum samples were collected at least 4 weeks post vaccination. Subsequently, multi-serotype enzyme-linked immunosorbent assay (ELISA) was performed. Eighty-seven children (under 12 years) were enrolled. Primary immunodeficiency disorder (PID) was the most common disorder (45) followed by possible immunodeficiency disorder (POID) (19), secondary immunodeficiency disorder (SID) (15), and mixed immunodeficiency disorder (MID) (8). The median age was 3 (1.50-5.33) years, 65% of patients were male. Deficient production of anti-PnPs IgG (titer ≤ 50 mg/L) was detected in 47 patients (54%), especially in the MID group, all of them under immunosuppressive therapy. In PCV13 responders, the mean of leukocyte population levels was higher with statistically significance differences in CD4 + /CD8 + T lymphocytes (p = 0.372, p = 0.014) and CD56 + /CD16 + NK (p = 0.016). Patients with previous bone marrow transplantation were the worst PCV13 responders. Pneumococcal IgG antibody titers (post-vaccination) along with clinical and analytical markers represented.

Lactobacillus supports Clostridiales to restrict gut colonization by multidrug-resistant Enterobacteriaceae.

Infections by multidrug-resistant Enterobacteriaceae (MRE) are life-threatening to patients. The intestinal microbiome protects against MRE colonization, but antibiotics cause collateral damage to commensals and open the way to colonization and subsequent infection. Despite the significance of this problem, the specific commensals and mechanisms that restrict MRE colonization remain largely unknown. Here, by performing a multi-omic prospective study of hospitalized patients combined with mice experiments, we find that Lactobacillus is key, though not sufficient, to restrict MRE gut colonization. Lactobacillus rhamnosus and murinus increase the levels of Clostridiales bacteria, which induces a hostile environment for MRE growth through increased butyrate levels and reduced nutrient sources. This mechanism of colonization resistance, an interaction between Lactobacillus spp. and Clostridiales involving cooperation between microbiota members, is conserved in mice and patients. These results stress the importance of exploiting microbiome interactions for developing effective probiotics that prevent infections in hospitalized patients.

Population-based sequencing of Mycobacterium tuberculosis reveals how current population dynamics are shaped by past epidemics.

Transmission is a driver of tuberculosis (TB) epidemics in high-burden regions, with assumed negligible impact in low-burden areas. However, we still lack a full characterization of transmission dynamics in settings with similar and different burdens. Genomic epidemiology can greatly help to quantify transmission, but the lack of whole genome sequencing population-based studies has hampered its application. Here, we generate a population-based dataset from Valencia region and compare it with available datasets from different TB-burden settings to reveal transmission dynamics heterogeneity and its public health implications. We sequenced the whole genome of 785 Mycobacterium tuberculosis strains and linked genomes to patient epidemiological data. We use a pairwise distance clustering approach and phylodynamic methods to characterize transmission events over the last 150 years, in different TB-burden regions. Our results underscore significant differences in transmission between low-burden TB settings, i.e., clustering in Valencia region is higher (47.4%) than in Oxfordshire (27%), and similar to a high-burden area as Malawi (49.8%). By modeling times of the transmission links, we observed that settings with high transmission rate are associated with decades of uninterrupted transmission, irrespective of burden. Together, our results reveal that burden and transmission are not necessarily linked due to the role of past epidemics in the ongoing TB incidence, and highlight the need for in-depth characterization of transmission dynamics and specifically tailored TB control strategies.

Invasive scedosporiosis in lung transplant recipients: A nine-year retrospective study in a tertiary care hospital.

BACKGROUND: Scedosporium species and Lomentospora prolificans (Sc/Lp) are emerging molds that cause invasive disease associated with a high mortality rate. After Aspergillus, these molds are the second filamentous fungi recovered in lung transplant (LT) recipients. AIMS: Our objective was to evaluate the incidence, risk factors and outcome of Sc/Lp infections in LT recipients at a tertiary care hospital with a national reference LT program. METHODS: A nine-year retrospective study was conducted. RESULTS: During this period, 395 LT were performed. Positive cultures for Sc/Lp were obtained from twenty-one LT recipients. Twelve patients (incidence 3.04%) developed invasive scedosporiosis (IS). In 66.7% of the patients with IS the invasive infection was defined as a breakthrough one. The main sites of infection were lungs and paranasal sinuses. Most of the patients received combination antifungal therapy. The IS crude mortality rate after 30 days was 16.7%, and 33.3% after a year. CONCLUSIONS: Our study highlights improved survival rates associated with combination antifungal therapy in LT recipients and underlines the risk of breakthrough infections in patients with allograft dysfunction on nebulized lipidic amphotericin B prophylaxis. In addition to pretransplant colonization, acute or chronic organ dysfunctions seem to be the main risk factors for IS.

The first wave of the COVID-19 epidemic in Spain was associated with early introductions and fast spread of a dominating genetic variant.

The coronavirus disease 2019 (COVID-19) pandemic has affected the world radically since 2020. Spain was one of the European countries with the highest incidence during the first wave. As a part of a consortium to monitor and study the evolution of the epidemic, we sequenced 2,170 samples, diagnosed mostly before lockdown measures. Here, we identified at least 500 introductions from multiple international sources and documented the early rise of two dominant Spanish epidemic clades (SECs), probably amplified by superspreading events. Both SECs were related closely to the initial Asian variants of SARS-CoV-2 and spread widely across Spain. We inferred a substantial reduction in the effective reproductive number of both SECs due to public-health interventions (Re < 1), also reflected in the replacement of SECs by a new variant over the summer of 2020. In summary, we reveal a notable difference in the initial genetic makeup of SARS-CoV-2 in Spain compared with other European countries and show evidence to support the effectiveness of lockdown measures in controlling virus spread, even for the most successful genetic variants.

A surface plasmon resonance based approach for measuring response to pneumococcal vaccine.

Incidence of pneumococcal disease has increased worldwide in recent years. Response to pneumococcal vaccine is usually measured using the multiserotype enzyme-linked immunosorbent assay (ELISA) pneumococcal test. However, this approach presents several limitations. Therefore, the introduction of new and more robust analytical approaches able to provide information on the efficacy of the pneumococcal vaccine would be very beneficial for the clinical management of patients. Surface plasmon resonance (SPR) has been shown to offer a valuable understanding of vaccines' properties over the last years. The aim of this study is to evaluate the reliability of SPR for the anti-pneumococcal capsular polysaccharides (anti-PnPs) IgGs quantification in vaccinated. Fast protein liquid chromatography (FPLC) was used for the isolation of total IgGs from serum samples of vaccinated patients. Binding-SPR assays were performed to study the interaction between anti-PnPs IgGs and PCV13. A robust correlation was found between serum levels of anti-PnPs IgGs, measured by ELISA, and the SPR signal. Moreover, it was possible to correctly classify patients into "non-responder", "responder" and "high-responder" groups according to their specific SPR PCV13 response profiles. SPR technology provides a valuable tool for reliably characterize the interaction between anti-PnPs IgGs and PCV13 in a very short experimental time.

Streptococcus agalactiae in childbearing age immigrant women in Comunitat Valenciana (Spain).

Streptococcus agalactiae (GBS) remains the leading cause of meningitis and neonatal sepsis in the world, and causes disease in pregnant and puerperal women. This is a retrospective study of GBS infections on women of childbearing age living in Comunitat Valenciana, Spain (years 2009-2014) and GBS colonization rate on pregnant women attending Hospital La Fe (years 2013-2015) according to their origin. An aggregated total of 6,641,960 women exposed during the study period had an average GBS isolation rate of 5.19‰ (5.14-5.25‰), geographical group rates being: Western Europe (2.2‰), North America (2.1‰), Australia (3.7‰), Spain (4.6‰), Latin America II (4.5‰), Eastern Europe (5.3‰), Asia (6.7‰), Latin America I (7.7‰), Middle East (7.9‰), Indian Subcontinent (17.2‰), North Africa (17.8‰), Sub-Saharan Africa (22.7‰). The 4532 pregnant women studied had an average GBS colonization rate of 12.47% (11.51-13.43) and geographical group rates varied similar to geographical isolation rates. Low GDP and high temperatures of the birth country were associated with higher colonization rates. Thus, differences in GBS colonization depend on the country of origin; Africa and the Indian subcontinent presented the highest, while Western Europe and North America had the lowest. This variability portrays a geographical pattern influenced by temperature and GDP.

Cutaneous and mucocutaneous leishmaniasis: experience of a Mediterranean hospital.

BACKGROUND: Leishmaniasis, considered by the World Health Organization as one of the most important tropical diseases, is endemic in the Mediterranean Basin. The aim of this study was to evaluate epidemiological and clinical characteristics of cutaneous (CL) and mucocutaneous leishmaniasis (MCL) in La Fe University Hospital, Valencia, Spain. The particular focus was on diagnosis techniques and clinical differences according to the immunological status of the patients. METHODS: An eleven-year retrospective observational study of CL and MCL episodes at the hospital was performed. Epidemiological, clinical and therapeutic variables of each case, together with the microbiological and anatomopathological diagnosis, were analyzed. RESULTS: A total of 42 patients were included, 30 of them were male and 28 were immunocompetent. Most of the cases (36/42) were diagnosed in the last 5 years (2013-2017). The incidence of CL and MCL increased from 3.6/100,000 (2006-2012) to 13.58/100,000 (2013-2017). The majority of the patients (37/42) exhibited CL, in 30 cases as single lesions (30/37). Ulcerative lesions were more common in immunosuppressed patients (13/14) than in immunocompetent patients (20/28), (P = 0.2302). The length of lesion presence before diagnosis was 7.36 ± 6.72 months in immunocompetent patients and 8.79 ± 6.9 months in immunosuppressed patients (P = 0.1863). Leishmania DNA detection (92.3%) was the most sensitive diagnostic technique followed by Giemsa stain (65%) and histopathological examination (53.8%). Twelve patients (12/42) had close contact with dogs or were living near to kennels, and 10 of them did not present underlying conditions. Intralesional glucantime (21/42) and liposomal amphotericin B (7/42) were the most common treatments administered in monotherapy. All patients evolved successfully and no relapse was reported. CONCLUSIONS: Some interesting clinical and epidemiological differences were found in our series between immunocompetent and immunosuppressed patients. Future studies can take these results further especially by studying patients with biological therapy. Skin biopsies combining NAAT with histological techniques are the most productive techniques for CL or MCL diagnosis.

High Heterogeneity of Multidrug-Resistant Enterobacteriaceae Fecal Levels in Hospitalized Patients Is Partially Driven by Intravenous ß-Lactams.

Multidrug-resistant Enterobacteriaceae (MRE) colonize the intestine asymptomatically from where they can breach into the bloodstream and cause life-threatening infections, especially in heavily colonized patients. Despite the clinical relevance of MRE colonization levels, we know little about how they vary in hospitalized patients and the clinical factors that determine those levels. Here, we conducted one of the largest studies of MRE fecal levels by tracking longitudinally 133 acute leukemia patients and monitoring their MRE levels over time through extensive culturing. MRE were defined as Enterobacteriaceae species that acquired nonsusceptibility to ≥1 agent in ≥3 antimicrobial categories. In addition, due to the selective media used, the MRE had to be resistant to third-generation cephalosporins. MRE were detected in 60% of the patients, but their fecal levels varied considerably among patients and within the same patient (>6 and 4 orders of magnitude, respectively). Multivariate analysis of clinical metadata revealed an impact of intravenous beta-lactams (i.e., meropenem and piperacillin-tazobactam), which significantly diminished the fecal MRE levels in hospitalized patients. Consistent with a direct action of beta-lactams, we found an effect only when the patient was colonized with strains sensitive to the administered beta-lactam (P < 0.001) but not with nonsusceptible strains. We report previously unobserved inter- and intraindividual heterogeneity in MRE fecal levels, suggesting that quantitative surveillance is more informative than qualitative surveillance of hospitalized patients. In addition, our study highlights the relevance of incorporating antibiotic treatment and susceptibility data of gut-colonizing pathogens for future clinical studies and in clinical decision-making.

Genomic characterization of Citrobacter freundii strains coproducing OXA-48 and VIM-1 carbapenemase enzymes isolated in leukemic patient in Spain.

Background: The emergence of carbapenemase-producing (CP) Citrobacter freundii poses a significant threat to public health, especially in high-risk populations. In this study, whole genome sequencing was used to characterize the carbapenem resistance mechanism of three C. freundii clinical isolates recovered from fecal samples of patients with acute leukemia (AL) from Spain. Materials and methods: Twelve fecal samples, collected between 2013 and 2015 from 9 patients with AL, were screened for the presence of CP strains by selecting them on MacConkey agar supplemented with ertapenem (0.5 mg/L). Bacteria were identified by MALDI-TOF mass spectrometry and were phenotypically characterized. Whole genome sequencing of C. freundii isolates was performed using the MinION and MiSeq Illumina sequencers. Bioinformatic analysis was performed in order to identify the molecular support of carbapenem resistance and to study the genetic environment of carbapenem resistance encoding genes. Results: Three carbapenem-resistant C. freundii strains (imipenem MIC≥32 mg/L) corresponding to three different AL patients were isolated. Positive modified Carba NP test results suggested carbapenemase production. The genomes of each C. freundii tested were assembled into a single chromosomal contig and plasmids contig. In all the strains, the carbapenem resistance was due to the coproduction of OXA-48 and VIM-1 enzymes encoded by genes located on chromosome and on an IncHI2 plasmid, respectively. According to the MLST and the SNPs analysis, all strains belonged to the same clone ST169. Conclusion: We report in our study, the intestinal carrying of C. freundii clone ST169 coproducing OXA-48 and VIM-1 identified in leukemic patients.

High-resolution mapping of tuberculosis transmission: Whole genome sequencing and phylogenetic modelling of a cohort from Valencia Region, Spain.

BACKGROUND: Whole genome sequencing provides better delineation of transmission clusters in Mycobacterium tuberculosis than traditional methods. However, its ability to reveal individual transmission links within clusters is limited. Here, we used a 2-step approach based on Bayesian transmission reconstruction to (1) identify likely index and missing cases, (2) determine risk factors associated with transmitters, and (3) estimate when transmission happened. METHODS AND FINDINGS: We developed our transmission reconstruction method using genomic and epidemiological data from a population-based study from Valencia Region, Spain. Tuberculosis (TB) incidence during the study period was 8.4 cases per 100,000 people. While the study is ongoing, the sampling frame for this work includes notified TB cases between 1 January 2014 and 31 December 2016. We identified a total of 21 transmission clusters that fulfilled the criteria for analysis. These contained a total of 117 individuals diagnosed with active TB (109 with epidemiological data). Demographic characteristics of the study population were as follows: 80/109 (73%) individuals were Spanish-born, 76/109 (70%) individuals were men, and the mean age was 42.51 years (SD 18.46). We found that 66/109 (61%) TB patients were sputum positive at diagnosis, and 10/109 (9%) were HIV positive. We used the data to reveal individual transmission links, and to identify index cases, missing cases, likely transmitters, and associated transmission risk factors. Our Bayesian inference approach suggests that at least 60% of index cases are likely misidentified by local public health. Our data also suggest that factors associated with likely transmitters are different to those of simply being in a transmission cluster, highlighting the importance of differentiating between these 2 phenomena. Our data suggest that type 2 diabetes mellitus is a risk factor associated with being a transmitter (odds ratio 0.19 [95% CI 0.02-1.10], p < 0.003). Finally, we used the most likely timing for transmission events to study when TB transmission occurred; we identified that 5/14 (35.7%) cases likely transmitted TB well before symptom onset, and these were largely sputum negative at diagnosis. Limited within-cluster diversity does not allow us to extrapolate our findings to the whole TB population in Valencia Region. CONCLUSIONS: In this study, we found that index cases are often misidentified, with downstream consequences for epidemiological investigations because likely transmitters can be missed. Our findings regarding inferred transmission timing suggest that TB transmission can occur before patient symptom onset, suggesting also that TB transmits during sub-clinical disease. This result has direct implications for diagnosing TB and reducing transmission. Overall, we show that a transition to individual-based genomic epidemiology will likely close some of the knowledge gaps in TB transmission and may redirect efforts towards cost-effective contact investigations for improved TB control.

Detection of plasmid-mediated colistin resistance, mcr-1 gene, in Escherichia coli isolated from high-risk patients with acute leukemia in Spain.

BACKGROUND: Bacterial infections in immunocompromised patients are associated with a high mortality and morbidity rate. In this high-risk group, the presence of multidrug-resistant (MDR) bacteria, particularly bacteria that harbor a transferable antibiotic resistance gene, complicates the management of bacterial infections. In this study, we investigated the presence of the transferable colistin resistance mcr genes in patients with leukemia in Spain. METHODS: 217 fecal samples collected in 2013-2015 from 56 patients with acute leukemia and colonized with MDR Enterobacteriaceae strains, were screened on September 2017 for the presence of the colistin resistance mcr genes (mcr-1 to -5) by multiplex PCR. mcr positive strains selected on LBJMR and MacConkey supplemented with colistin (2 µg/ml) media were phenotypically and molecularly characterized by antimicrobial susceptibility testing, minimum inhibitory concentration, multilocus sequence typing and plasmid characterization. RESULTS: Among 217 fecal samples, 5 samples collected from 3 patients were positive for the presence of the mcr-1 colistin-resistance gene. Four Escherichia coli strains were isolated and exhibited resistance to colistin with MIC = 4 µg/ml. Other genes conferring the resistance to ß-lactam antibiotics have also been identified in mcr-1 positive strains, including blaTEM-206 and blaTEM-98. Three different sequence types were identified, including ST1196, ST140 and ST10. Plasmid characterization allowed us to detect the mcr-1 colistin resistance gene on conjugative IncP plasmid type. CONCLUSION: To the best of our knowledge, we have identified the mcr-1 gene for the first time in leukemia patients in Spain. In light of these results, strict measures have been implemented to prevent its dissemination.

Detection and treatment of Candida auris in an outbreak situation: risk factors for developing colonization and candidemia by this new species in critically ill patients.

BACKGROUND: Candida auris is an emerging, multidrug-resistant yeast causing hospital outbreaks. This study describes the first 24 months of the ongoing C. auris outbreak in our hospital and analyzes predisposing factors to C. auris candidemia/colonization. RESEARCH DESIGN AND METHODS: A 12-month prospective, case-controlled study was performed including a total of 228 patients (114 colonized/candidemia and 114 controls). Data from the first 79 candidemia episodes and 738 environmental samples were also analyzed. Definitive C. auris identification was performed by ITS sequencing. Antifungal susceptibility was carried out by EUCAST methodology. RESULTS: Polytrauma (32%), cardiovascular disease (25%), and cancer (17%) were the most common underlying condition in colonized/candidemia patients. Indwelling CVC (odds ratio {OR}, 13.48), parenteral nutrition (OR, 3.49), and mechanical ventilation (OR, 2.43) remained significant predictors of C. auris colonization/candidemia. C. auris was most often isolated on sphygmomanometer cuffs (25%) patient tables (10.2%), keyboards (10.2%), and infusion pumps (8.2%). All isolates were fully resistant to fluconazole (MICs >64 mg/L) and had significantly reduced susceptibility to voriconazole (GM, 1.8 mg/L). CONCLUSIONS: Predictor conditions to C. auris colonization/candidemia are similar to other Candida species. C. auris colonizes multiple patient's environment surfaces. All isolates are resistant to fluconazole and had significant reduced susceptibility to voriconazole.