Respiratory syncytial virus incidence and typing in the last six seasons in the north of Spain (Asturias). Genetic characterization during the SARS-CoV-2 pandemic.

Respiratory syncytial virus is associated with lower respiratory tract infections. As several types and genotypes can circulate at the same time, genomic characterization is important for timely epidemiological control and treatment measures. In the last 6 seasons (2017-2023), 191 236 nasopharyngeal swabs were processed for respiratory viruses to determine the etiology of acute respiratory infections, describe the incidence and distribution of RSV types and enrich the data of epidemiological molecular studies on RSV in Spain. The incidence of RSV reached 7% in the pre-pandemic season. RSV was most frequent in children under 5 years of age (12.6%), but was also significant in those over 70 years of age (5.63%). The measures taken to control SARS-CoV-2 infection were useful for RSV control and the incidence decreased to 1.8%, but caused a change in the types. Pre-pandemic, the majority circulating types were RSV-B/RSV-B/RSV-A and in the pandemic it was RSV-B/RSV-B. In the last season, RSV-B and RSV-A were detected in the same proportion. Genetic characterization showed three new clades. This has been taken into account to understand the epidemiology as well as the development of therapeutic and preventive strategies.

Transmitted Drug Resistance and HIV Diversity Among Adolescents Newly Diagnosed With HIV in Spain.

BACKGROUND: Virologic characterization of newly HIV-diagnosed adolescents could help to improve their specific needs. The objective was to describe the transmitted drug resistance mutations (TDR) and its transmission by clusters in this population in Spain. METHODS: TDR to retrotranscriptase and protease inhibitors included in the WHO TDR list 2009 implemented in the Calibrated Population Resistance tool v8.0 (Stanford) were studied in HIV pol sequences from all HIV-diagnosed adolescents (12-19-year-old) enrolled during 2004-2019 period in the Spanish pediatric and adult (CoRISpe-CoRIS) cohorts. The found TDR were compared with the provided by the Stanford algorithm v9.0 2021. HIV-1 variants and transmission clusters were also studied. RESULTS: Among 410 HIV-1 adolescents diagnosed, 141 (34.4%) had available ART-naive sequences. They were mostly male (81.6%), Spanish (55.3%) and with behavioral risk (92.2%), mainly male-to-male sexual contact (63.1%). TDR prevalence was significantly higher by Stanford versus WHO list (18.4% vs. 7.1%; P = 0.004). The most prevalent TDR by the WHO list was K103N (3.6%) and by Stanford E138A (6.6%), both at retrotranscriptase. E138A, related to rilpivirine/etravirine resistance, was absent in the WHO list. One in 4 adolescents carried HIV-1 non-B variants. We described 5 transmission clusters, and 2 carried TDR mutations. CONCLUSIONS: Our data suggest a high TDR prevalence in adolescents with a new HIV diagnosis in Spain, similar to adults, 2 active TDR transmission clusters, and the need for the WHO TDR list update. These findings could have implications for the options of the recently available rilpivirine-related long-acting treatment and in first-line regimen election.

Rapid expansion of lymphogranuloma venereum infections with fast diversification and spread of Chlamydia trachomatis L genovariants.

IMPORTANCE: Numerous international organizations, including the World Health Organization, have been drawing attention to the global increase in sexually transmitted infections. Twenty years ago, lymphogranuloma venereum (LGV) was mainly considered a tropical disease; in recent decades, however, LGV has been increasingly present in high-income countries. This increase has been linked to men who have sex with men who participate in highly interconnected sexual networks, leading to a rapid spread of LGV. This study focuses on the spread of LGV, presenting the largest time series of LGV prevalence in Spain, which includes more than a thousand diagnosed cases in one large city. The number of LGV cases diagnosed was analyzed over time, and a selection of strains was subjected to molecular genotyping. The results indicate that the LGV epidemic is gradually evolving toward an increasingly complex diversification due to the selection of successful genovariants that have emerged by mutation and recombination events, suggesting that we are moving toward an unpredictable scenario.

Monitoring and tracking the spread of SARS-CoV-2 in Asturias, Spain.

Mutational analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can quantify the relative importance of variants over time, enable dominant mutations to be identified, and facilitate near real-time detection, comparison and tracking of evolving variants. SARS-CoV-2 in Asturias, an autonomous community of Spain with a large ageing population, and high levels of migration and tourism, was monitored and tracked from the beginning of the pandemic in February 2020 until its decline and stabilization in August 2021, and samples were characterized using whole genomic sequencing and single nucleotide polymorphisms. Data held in the GISAID database were analysed to establish patterns in the appearance and persistence of SARS-CoV-2 strains. Only 138 non-synonymous mutations occurring in more than 1 % of the population with SARS-CoV-2 were found, identifying ten major variants worldwide (seven arose before January 2021), 19 regional and one local. In Asturias only 17 different variants were found. After vaccination, no further regional major variants were found. Only half of the defined variants circulated and no new variants were generated, indicating that infection control measures such as rapid diagnosis, isolation and vaccination were efficient.

Detecting, Quantifying, and Isolating Monkeypox Virus in Suspected Cases, Spain.

When a monkeypox virus outbreak began in several parts of the world in May 2022, timely and accurate diagnosis became mandatory. In our laboratory, a real-time quantitative PCR was designed and evaluated in several patient samples and compared with isolation results. Genomic viral load was related to virus viability.

Drug resistance in children and adolescents with HIV in Panama.

OBJECTIVES: The inadequacy of resistance monitoring in Latin America leads to circulation of HIV strains with drug resistance mutations (DRMs), compromising ART effectiveness. This study describes the DRM prevalence in HIV-infected paediatric patients in Panama. METHODS: During 2018-19, plasma was collected from 76 HIV-infected children/adolescents (5 ART-naive, 71 treated) in Panama for HIV-1 DRM pol analysis, predicted antiretroviral (ARV) susceptibility by Stanford, and HIV-1 variant phylogenetic characterization. RESULTS: HIV-1 pol sequences were recovered from 67 (88.2%) of 76 children/adolescents (median age 12 years), carrying 65 subtype B, 1 subtype G and 1 unique recombinant URF_A1B. Five were ART-naive and 62 ART-treated under virological failure (viraemia >50 copies/mL) with previous exposure to NRTIs, (100%), NNRTIs (45.2%), PIs (95.2%) and integrase strand transfer inhibitors (INSTIs, 17.7%). Among the treated patients, 34 (54.8%) carried resistant strains, with major DRMs to one (40.3%), two (9.7%) or three (4.8%) ARV families. Most of them harboured DRMs to NRTIs (58.5%) or NNRTIs (39%), but also major DRMs to PIs (4.9%) and INSTIs (6.5%). We also found dual-class NRTI + NNRTI (12.2%) and NNRTI + PI (2.6%) resistance. Two naive subjects carried viruses with DRMs to NRTIs and NRTI + NNRTI, respectively. Sequenced viruses presented high/intermediate resistance mainly to emtricitabine/lamivudine (48.9% each) and efavirenz/nevirapine (33.3% each). Most participants were susceptible to PIs (91.3%) and INSTIs (88.1%). CONCLUSIONS: The high DRM prevalence to NRTIs and NNRTIs observed among treated HIV-infected children/adolescents in Panama justifies the need for routine resistance monitoring for optimal rescue therapy selection in this vulnerable population.

The unexpected high prevalence of HBV subgenotype D4 in patients with chronic hepatitis B in Galicia, a northwestern Spanish region, reflects strong links with Latin America.

BACKGROUND: Hepatitis B virus (HBV) comprises 9 genotypes and multiple subgenotypes that depict differences in geographic distribution, clinical outcome and response to antiviral therapy. However, the molecular epidemiology of HBV geno/subgenotypes is globally scarce. In Spain, HBV genotype D seems to be more prevalent in the northwestern regions compared to the rest of the country for unclear reasons. METHODS: HBV genotyping was performed using geno2pheno on a S gene fragment amplified from plasma collected from all chronic hepatitis B individuals attended at one reference hospital in Santiago de Compostela, the Galicia's capital town. Phylogenetic and phylogeographic analyses using a fragment of 345 bp were performed in all viremic specimens. To avoid misleading allocation as consequence of short fragment analysis, several bioinformatic controls were used. RESULTS: A total of 320 individuals with persistent serum HBsAg+ and detectable HBV-DNA were seen between 2000 and 2016 (male 68.4%; median age, 52 years-old; native Spaniards 83.8%). HBV genotype distribution was as follows: A 15.3%; B 1.6%; C 2.5%; D 71.6%; E 3.1%; F 2.2%; G 3.1%; and H 0.6%. HBV genotype D was mostly represented by D4 and D2 subgenotypes (33.4% and 15% of total, respectively). Compared to chronic hepatitis B patients with genotypes B, C, E and G, HBV-D4 carriers tended to be older (54.2% had >50 years-old) and HBeAg-negative (85%). Moreover, 43% were female, 4.7% had cirrhosis, 10.2% hepatitis C and 6.4% HIV coinfection. Phylogenetic analyses could be performed on 82 HBV-D4 specimens; and 79 were confirmed as HBV-D4 using PhyML. Phylogeography using FasTree suggested at least two distinct introductions of HBV-D4 in Galicia, one from the Caribbean and South America, and another from India. CONCLUSIONS: HBV subgenotype D4 is the most prevalent HBV variant in chronic hepatitis B patients living in the northwest of Spain, representing 33.4% (107/320) of all chronic hepatitis B infections. This rate of HBV-D4 is among the highest reported worldwide. Epidemiological and phylogenetic analyses suggest a strong association with historical migrant exchanges with Latin America, and especially with the Caribbean basin.

Quantification of plasmid copy number as surrogate marker of virulence among different invasive and non-invasive genotypes of Chlamydia trachomatis.

The population dissemination of invasive genotypes of C. trachomatis and an increase of urogenital infections cases by non-invasive genotypes have been observed in many countries. In this epidemiological context, the descriptions of a high proportion of infections related to L-genotypes in asymptomatic patients, but also to infections caused by non-L genotypes in symptomatic patients have been unexpected finding. The plasmid copy number (PCN) has been proposed as a surrogate marker of virulence. We quantified the PCN in 233 samples and 179 samples carrying L-genotype and non-L genotypes respectively. A significant difference in the median of PCN was detected between symptomatic/asymptomatic patients (P < 0.001), independently of the genotype. Moreover, PCN could vary, in the same strain, among different anatomical sites suggesting that micro-environmental changes could affect virulence. These findings suggest that the quantification of PCN in clinical samples could improve the management of patients.

Specific high-resolution scheme to improve understanding of the spatio-temporal dispersion of lymphogranuloma venereum epidemic.

Introduction: Lymphogranuloma venereum (LGV) is already endemic in vulnerable populations in several European countries; however, molecular epidemiology data with improved accuracy are necessary to better understand LGV epidemic in these countries. Current strategies to study the molecular epidemiology of LGV cases involve schemes based on a few genetic fragments of Chlamydia trachomatis, which have demonstrated limited discriminatory power for LGV. Therefore, this study aimed to propose a new combination of molecular markers based on the most variable genes of L-genotype genomes to improve the characterization of the current LGV epidemic in Madrid, Spain. Methods: Four genes were selected according to their diversity index (CTLon_0054, CTLon_0087, CTLon_0243 and CTLon_0301) for use in combination with ompA. In silico and experimental studies were performed to compare the previously described multilocus sequence typing (MLST) schemes with our proposal. Moreover, the proposed scheme was applied (n = 68) to analyze the spatio-temporal spread of the LGV cases. Results: Our proposal demonstrated higher diversity allowing the identification of three main groups compared to the previously published MLST based on hypervariable genes wherein only a single sequence type was identified. The temporal analysis showed that the major cluster was progressively diversifying, revealing a very active transmission chain. Furthermore, an L2b genome identical to that of the origin of the epidemic was detected, suggesting reintroductions or a low screening rate in vulnerable populations. The spatial distribution suggests that the selection and spread of new variants occurs from the central district to the peripheral regions. Discussion: The scheme proposed in this study has proven to be useful for appropriate discrimination of LGV strains. This study, to our knowledge for the first time, demonstrates a spatio-temporal spread that increases our understanding and identifies areas with special susceptibility for maintenance of the endemic situation of LGV.

High Drug Resistance Levels Compromise the Control of HIV Infection in Pediatric and Adult Populations in Bata, Equatorial Guinea.

A lack of HIV viral load (VL) and HIV drug resistance (HIVDR) monitoring in sub-Saharan Africa has led to an uncontrolled circulation of HIV-strains with drug resistance mutations (DRM), compromising antiretroviral therapy (ART). This study updates HIVDR data and HIV-1 variants in Equatorial Guinea (EG), providing the first data on children/adolescents in the country. From 2019−2020, 269 dried blood samples (DBS) were collected in Bata Regional Hospital (EG) from 187 adults (73 ART-naïve/114 ART-treated) and 82 children/adolescents (25 HIV-exposed-ART-naïve/57 ART-treated). HIV-1 infection was confirmed in Madrid by molecular/serological confirmatory tests and ART-failure by VL quantification. HIV-1 pol region was identified as transmitted/acquired DRM, predicted antiretroviral susceptibility (Stanfordv9.0) and HIV-1 variants (phylogeny). HIV infection was confirmed in 88.1% of the individuals and virological failure (VL > 1000 HIV-1-RNA copies/mL) in 84.2/88.9/61.9% of 169 ART-treated children/adolescents/adults. Among the 167 subjects with available data, 24.6% suffered a diagnostic delay. All 125 treated had experienced nucleoside retrotranscriptase inhibitors (NRTI); 95.2% were non-NRTI (NNRTI); 22.4% had experienced integrase inhibitors (INSTI); and 16% had experienced protease inhibitors (PI). At sampling, they had received 1 (37.6%), 2 (32%), 3 (24.8%) or 4 (5.6%) different ART-regimens. Among the 43 treated children−adolescents/37 adults with sequence, 62.8/64.9% carried viruses with major-DRM. Most harbored DRM to NNRTI (68.4/66.7%), NRTI (55.3/43.3%) or NRTI+NNRTI (50/33.3%). One adult and one child carried major-DRM to PI and none carried major-DRM to INSTI. Most participants were susceptible to INI and PI. DRM was absent in 36.2% of treated patients with VL > 1000 cp/mL, suggesting adherence failure. TDR prevalence in 59 ART-naïve adults was high (20.3%). One-half (53.9%) of the 141 subjects with pol sequence carried CRF02_AG. The observed high rate of ART-failure and transmitted/acquired HIVDR could compromise the 95-95-95-UNAIDS targets in EG. Routine VL and resistance monitoring implementation are mandatory for early detection of ART-failure and optimal rescue therapy selection ART regimens based on PI, and INSTI can improve HIV control in EG.

Emergence and Spread of B.1.1.7 Lineage in Primary Care and Clinical Impact in the Morbi-Mortality among Hospitalized Patients in Madrid, Spain.

In December 2020, UK authorities warned of the rapid spread of a new SARS-CoV-2 variant, belonging to the B.1.1.7 lineage, known as the Alpha variant. This variant is characterized by 17 mutations and 3 deletions. The deletion 69-70 in the spike protein can be detected by commercial platforms, allowing its real-time spread to be known. From the last days of December 2020 and over 4 months, all respiratory samples with a positive result for SARS-CoV-2 from patients treated in primary care and the emergency department were screened to detect this variant based on the strategy S gene target failure (SGTF). The first cases were detected during week 53 (2020) and reached >90% of all cases during weeks 15-16 (2021). During this period, the B.1.1.7/SGTF variant spread at a rapid and constant replacement rate of around 30-36%. The probability of intensive care unit admission was twice higher among patients infected by the B.1.1.7/SGTF variant, but there were no differences in death rate. During the peak of the third pandemic wave, this variant was not the most prevalent, and it became dominant when this wave was declining. Our results confirm that the B.1.1.7/SGTF variant displaced other SARS-CoV-2 variants in our healthcare area in 4 months. This displacement has led to an increase in the burden of disease.

The silent epidemic of lymphogranuloma venereum inside the COVID-19 pandemic in Madrid, Spain, March 2020 to February 2021.

Despite social distancing measures implemented in Madrid to prevent the propagation of SARS-CoV-2, a significant increase (57.1%; 28.5 to 38.5 cases/month) in cases of lymphogranuloma venereum was detected during the COVID-19 pandemic. This unusual scenario might have accelerated a shift in Chlamydia trachomatis (CT) epidemiology towards a higher proportion of L genotypes compared with non-L genotypes in CT-positive samples. Our data underscore the importance of surveillance of sexually transmitted infections during the pandemic, in particular among vulnerable populations.

Genomic Epidemiology of SARS-CoV-2 in Madrid, Spain, during the First Wave of the Pandemic: Fast Spread and Early Dominance by D614G Variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in Madrid, Spain, on 25 February 2020. It increased in frequency very fast and by the end of May more than 70,000 cases had been confirmed by reverse transcription-polymerase chain reaction (RT-PCR). To study the lineages and the diversity of the viral population during this first epidemic wave in Madrid we sequenced 224 SARS-CoV-2 viral genomes collected from three hospitals from February to May 2020. All the known major lineages were found in this set of samples, though B.1 and B.1.5 were the most frequent ones, accounting for more than 60% of the sequences. In parallel with the B lineages and sublineages, the D614G mutation in the Spike protein sequence was detected soon after the detection of the first coronavirus disease 19 (COVID-19) case in Madrid and in two weeks became dominant, being found in 80% of the samples and remaining at this level during all the study periods. The lineage composition of the viral population found in Madrid was more similar to the European population than to the publicly available Spanish data, underlining the role of Madrid as a national and international transport hub. In agreement with this, phylodynamic analysis suggested multiple independent entries before the national lockdown and air transportation restrictions.

Current and historic HIV-1 molecular epidemiology in paediatric and adult population from Kinshasa in the Democratic Republic of Congo.

HIV-1 diversity may impact monitoring and vaccine development. We describe the most recent data of HIV-1 variants and their temporal trends in the Democratic Republic of Congo (DRC) from 1976 to 2018 and in Kinshasa from 1983-2018. HIV-1 pol sequencing from dried blood collected in Kinshasa during 2016-2018 was done in 340 HIV-infected children/adolescents/adults to identify HIV-1 variants by phylogenetic reconstructions. Recombination events and transmission clusters were also analyzed. Variant distribution and genetic diversity were compared to historical available pol sequences from the DRC in Los Alamos Database (LANL). We characterized 165 HIV-1 pol variants circulating in Kinshasa (2016-2018) and compared them with 2641 LANL sequences from the DRC (1976-2012) and Kinshasa (1983-2008). During 2016-2018 the main subtypes were A (26.7%), G (9.7%) and C (7.3%). Recombinants accounted for a third of infections (12.7%/23.6% Circulant/Unique Recombinant Forms). We identified the first CRF47_BF reported in Africa and four transmission clusters. A significant increase of subtype A and sub-subtype F1 and a significant reduction of sub-subtype A1 and subtype D were observed in Kinshasa during 2016-2018 compared to variants circulating in the city from 1983 to 2008. We provide unique and updated information related to HIV-1 variants currently circulating in Kinshasa, reporting the temporal trends of subtypes/CRF/URF during 43 years in the DRC, and providing the most extensive data on children/adolescents.

Stratified reconstruction of ancestral Escherichia coli diversification.

BACKGROUND: Phylogenetic analyses of the bacterial genomes based on the simple classification in core- genes and accessory genes pools could offer an incomplete view of the evolutionary processes, of which some are still unresolved. A combined strategy based on stratified phylogeny and ancient molecular polymorphisms is proposed to infer detailed evolutionary reconstructions by using a large number of whole genomes. This strategy, based on the highest number of genomes available in public databases, was evaluated for improving knowledge of the ancient diversification of E. coli. This staggered evolutionary scenario was also used to investigate whether the diversification of the ancient E. coli lineages could be associated with particular lifestyles and adaptive strategies. RESULTS: Phylogenetic reconstructions, exploiting 6220 available genomes in Genbank, established the E. coli core genome in 1023 genes, representing about 20% of the complete genome. The combined strategy using stratified phylogeny plus molecular polymorphisms inferred three ancient lineages (D, EB1A and FGB2). Lineage D was the closest to E. coli root. A staggered diversification could also be proposed in EB1A and FGB2 lineages and the phylogroups into these lineages. Several molecular markers suggest that each lineage had different adaptive trajectories. The analysis of gained and lost genes in the main lineages showed that functions of carbohydrates utilization (uptake of and metabolism) were gained principally in EB1A lineage, whereas loss of environmental-adaptive functions in FGB2 lineage were observed, but this lineage showed higher accumulated mutations and ancient recombination events. The population structure of E. coli was re-evaluated including up to 7561 new sequenced genomes, showing a more complex population structure of E. coli, as a new phylogroup, phylogroup I, was proposed. CONCLUSIONS: A staggered reconstruction of E. coli phylogeny is proposed, indicating evolution from three ancestral lineages to reach all main known phylogroups. New phylogroups were confirmed, suggesting an increasingly complex population structure of E. coli. However these new phylogroups represent < 1% of the global E. coli population. A few key evolutionary forces have driven the diversification of the two main E. coli lineages, metabolic flexibility in one of them and colonization-virulence in the other.

Comparative evaluation of the identification of rapidly growing non-tuberculous mycobacteria by mass spectrometry (MALDI-TOF MS), GenoType Mycobacterium CM/AS assay and partial sequencing of the rpoBeta gene with phylogenetic analysis as a reference method / Evaluación comparativa de la identificación de micobacterias no tuberculosas de crecimiento rápido mediante espectrometría de masas (MALDI-TOF MS), GenoType(R) Mycobacterium CM/AS assay y la secuenciación parcial del gen rpoBeta con análisis filogenético como método de referencia

Introduction: The American Thoracic Society and the Infectious Diseases Society of America recommend that clinically significant non-tuberculous mycobacteria (NTM) should be identified to the species level in order to determine their clinical significance. The aim of this study was to evaluate identification of rapidly growing NTM (RGM) isolated from clinical samples by using MALDI-TOF MS and a commercial molecular system. The results were compared with identification using a reference method. Methods: We included 46 clinical isolates of RGM and identified them using the commercial molecular system GenoType(R) CM/AS (Hain, Lifescience, Germany), MALDI-TOF MS (Bruker) and, as reference method, partial rpoBeta gene sequencing followed by BLAST and phylogenetic analysis with the 1093 sequences available in the GeneBank. Results: The degree of agreement between GenoType(R) and MALDI-TOF MS and the reference method, partial rpoBeta sequencing, was 27/43 (62.8%) and 38/43 cases (88.3%) respectively. For all the samples correctly classified by GenoType(R), we obtained the same result with MALDI-TOF MS (27/27). However, MALDI-TOF MS also correctly identified 68.75% (11/16) of the samples that GenoType(R) had misclassified (p = 0.005). Conclusions: MALDI-TOF MS classified significantly better than GenoType(R). When a MALDI-TOF MS score >1.85 was achieved, MALDI-TOF MS and partial rpoBeta gene sequencing were equivalent. GenoType(R) was not able to distinguish between species belonging to the M. fortuitum complex. MALDI-TOF MS methodology is simple, rapid and associated with lower consumable costs than GenoType(R). The partial rpoBeta sequencing methods with BLAST and phylogenetic analysis were not able to identify some RGM unequivocally. Therefore, sequencing of additional regions would be indicated in these cases

Introducción: La American Thoracic Society y la Infectious Diseases Society of America recomiendan que las micobacterias no tuberculosas (MNT) clínicamente relevantes sean identificadas a nivel de especie para determinar su significado clínico. El propósito de este estudio fue a partir de MNT de crecimiento rápido (MCR) aisladas en muestras clínicas, evaluar su identificación mediante MALDI-TOF MS y un método molecular comercial, comparando estos resultados con la identificación obtenida usando un método de referencia. Métodos: Se incluyeron 46 aislados clínicos de MCR. Estos aislados se identificaron mediante el método molecular comercial GenoType(R) Mycobacterium CM/AS (Hain, Lifescience, Alemania), MALDI-TOF MS (Bruker) y, como método de referencia, la secuenciación parcial del gen rpoBeta seguido de BLAST y análisis filogenético. Para el análisis filogenético se utilizaron 1.093 secuencias disponibles en el GeneBank. Resultados: Entre GenoType(R) o MALDI-TOF MS, la concordancia respecto al método de referencia, secuenciación parcial de rpoB, fue 27/43 (62,8%) y 38/43 casos (88,3%), respectivamente. En todas las muestras que GenoType(R) clasificó correctamente con MALDI-TOF MS se obtuvo el mismo resultado (27/27). Pero además MALDI-TOF MS identificó bien 68,75% (11/16) de las muestras que GenoType(R) no clasificó correctamente (p = 0,005). Conclusiones: MALDI-TOF MS clasificó significativamente mejor que GenoType(R). Cuando MALDI-TOF MS alcanzó una puntuación >1,85, MALDI-TOF y la secuenciación parcial del gen rpoβ fueron equivalentes. GenoType(R) no distinguió dentro del M. fortuitum complex. La metodología MALDI-TOF MS es simple, rápida y se asocia a un menor coste de consumibles que GenoType(R). La secuenciación parcial del gen rpoBeta con BLAST y análisis filogenético no lograron identificar de manera inequívoca algunas MCR. Para estas MCR estaría indicado la secuenciación de regiones adicionales

Comparative evaluation of the identification of rapidly growing non-tuberculous mycobacteria by mass spectrometry (MALDI-TOF MS), GenoType Mycobacterium CM/AS assay and partial sequencing of the rpoß gene with phylogenetic analysis as a reference method.

INTRODUCTION: The American Thoracic Society and the Infectious Diseases Society of America recommend that clinically significant non-tuberculous mycobacteria (NTM) should be identified to the species level in order to determine their clinical significance. The aim of this study was to evaluate identification of rapidly growing NTM (RGM) isolated from clinical samples by using MALDI-TOF MS and a commercial molecular system. The results were compared with identification using a reference method. METHODS: We included 46 clinical isolates of RGM and identified them using the commercial molecular system GenoType® CM/AS (Hain, Lifescience, Germany), MALDI-TOF MS (Bruker) and, as reference method, partial rpoß gene sequencing followed by BLAST and phylogenetic analysis with the 1093 sequences available in the GeneBank. RESULTS: The degree of agreement between GenoType® and MALDI-TOF MS and the reference method, partial rpoß sequencing, was 27/43 (62.8%) and 38/43 cases (88.3%) respectively. For all the samples correctly classified by GenoType®, we obtained the same result with MALDI-TOF MS (27/27). However, MALDI-TOF MS also correctly identified 68.75% (11/16) of the samples that GenoType® had misclassified (p=0.005). CONCLUSIONS: MALDI-TOF MS classified significantly better than GenoType®. When a MALDI-TOF MS score >1.85 was achieved, MALDI-TOF MS and partial rpoß gene sequencing were equivalent. GenoType® was not able to distinguish between species belonging to the M. fortuitum complex. MALDI-TOF MS methodology is simple, rapid and associated with lower consumable costs than GenoType®. The partial rpoß sequencing methods with BLAST and phylogenetic analysis were not able to identify some RGM unequivocally. Therefore, sequencing of additional regions would be indicated in these cases.

High Prevalence of Co-Infections by Invasive and Non-Invasive Chlamydia trachomatis Genotypes during the Lymphogranuloma Venereum Outbreak in Spain.

The evolution of Chlamydia trachomatis is mainly driven by recombination events. This fact can be fuelled by the coincidence in several European regions of the high prevalence of non-invasive urogenital genotypes and lymphogranuloma venereum (LGV) outbreaks. This scenario could modify the local epidemiology and favor the selection of new C. trachomatis variants. Quantifying the prevalence of co-infection could help to predict the potential risk in the selection of new variants with unpredictable results in pathogenesis or transmissibility. In the 2009-2013 period, 287 clinical samples with demonstrated presence of C. trachomatis were selected. They were divided in two groups. The first group was constituted by 137 samples with C. trachomatis of the LGV genotypes, and the second by the remaining 150 samples in which the presence of LGV genotypes was previously excluded. They were analyzed to detect the simultaneous presence of non-LGV genotypes based on pmpH and ompA genes. In the first group, co-infections were detected in 10.9% of the cases whereas in the second group the prevalence was 14.6%, which is the highest percentage ever described among European countries. Moreover, bioinformatic analyses suggested the presence among men who have sex with men of a pmpH-recombinant variant, similar to strains described in Seattle in 2002. This variant was the result of genetic exchange between genotypes belonging to LGV and members of G-genotype. Sequencing of other genes, phylogenetically related to pathotype, confirmed that the putative recombinant found in Madrid could have a common origin with the strains described in Seattle. Countries with a high prevalence of co-infections and high migration flows should enhance surveillance programs in at least their vulnerable population.

Recombination blurs phylogenetic groups routine assignment in Escherichia coli: setting the record straight.

The characterization of population structures plays a main role for understanding outbreaks and the dynamics of bacterial spreading. In Escherichia coli, the widely used combination of multiplex-PCR scheme together with goeBURST has some limitations. The purpose of this study is to show that the combination of different phylogenetic approaches based on concatenated sequences of MLST genes results in a more precise assignment of E. coli phylogenetic groups, complete understanding of population structure and reconstruction of ancestral clones. A collection of 80 Escherichia coli strains of different origins was analyzed following the Clermont and Doumith's multiplex-PCR schemes. Doumith's multiplex-PCR showed only 1.7% of misassignment, whereas Clermont's-2000 protocol reached 14.0%, although the discrepancies reached 30% and 38.7% respectively when recombinant C, F and E phylogroups were considered. Therefore, correct phylogroup attribution is highly variable and depends on the clonal composition of the sample. As far as population structure of these E. coli strains, including 48 E. coli genomes from GenBank, goeBURST provides a quite dispersed population structure; whereas NeighborNet approach reveals a complex population structure. MLST-based eBURST can infer different founder genotypes, for instance ST23/ST88 could be detected as the founder genotypes for STC23; however, phylogenetic reconstructions might suggest ST410 as the ancestor clone and several evolutionary trajectories with different founders. To improve our routine understanding of E. coli molecular epidemiology, we propose a strategy based on three successive steps; first, to discriminate three main groups A/B1/C, D/F/E and B2 following Doumith's protocol; second, visualization of population structure based on MLST genes according to goeBURST, using NeighborNet to establish more complex relationships among STs; and third, to perform, a cost-free characterization of evolutionary trajectories in variants emerging along the clonal expansion using parsimony methods of phylogenetic analysis.

Normal mutation rate variants arise in a Mutator (Mut S) Escherichia coli population.

The rate at which mutations are generated is central to the pace of evolution. Although this rate is remarkably similar amongst all cellular organisms, bacterial strains with mutation rates 100 fold greater than the modal rates of their species are commonly isolated from natural sources and emerge in experimental populations. Theoretical studies postulate and empirical studies teort the hypotheses that these "mutator" strains evolved in response to selection for elevated rates of generation of inherited variation that enable bacteria to adapt to novel and/or rapidly changing environments. Less clear are the conditions under which selection will favor reductions in mutation rates. Declines in rates of mutation for established populations of mutator bacteria are not anticipated if such changes are attributed to the costs of augmented rates of generation of deleterious mutations. Here we report experimental evidence of evolution towards reduced mutation rates in a clinical isolate of Escherichia coli with an hyper-mutable phenotype due a deletion in a mismatch repair gene, (ΔmutS). The emergence in a ΔmutS background of variants with mutation rates approaching those of the normal rates of strains carrying wild-type MutS was associated with increase in fitness with respect to ancestral strain. We postulate that such an increase in fitness could be attributed to the emergence of mechanisms driving a permanent "aerobic style of life", the negative consequence of this behavior being regulated by the evolution of mechanisms protecting the cell against increased endogenous oxidative radicals involved in DNA damage, and thus reducing mutation rate. Gene expression assays and full sequencing of evolved mutator and normo-mutable variants supports the hypothesis. In conclusion, we postulate that the observed reductions in mutation rate are coincidental to, rather than, the selective force responsible for this evolution.