RESUMEN
Dengue virus (DENV) is one of the most significant mosquito-borne diseases in Nepal. In 2023, DENV outbreaks began in Eastern Nepal, near the border with India, and rapidly spread nationwide. The study aims to describe the outbreak's epidemiological pattern, laboratory characteristics, DENV serotypes, and genotypes. A hospital-based cross-sectional study was conducted in four hospitals in Jhapa, Eastern Nepal, in 2023. Acute serum samples were obtained from dengue suspected patients within 7 days of illness and subjected to virus isolation, conventional and real-time polymerase chain reaction (RT-PCR), and phylogenetic analysis. Out of 60 samples, 42 (70 %), 11 (18.3 %) and 7 (11.7 %) were primary, secondary and non-dengue infection, respectively. Among 53 dengue confirmed patients, 46 (86.7 %) were positive for NS1 and 12 (22.6 %) were positive for both NS1 and IgM. Out of 42 dengue isolates, a new clade of the cosmopolitan genotype of DENV-2 was the most prevalent (28, 66.7 %), followed by genotype III of DENV-3 (11, 26.2 %) and genotype V of DENV-1 (3, 7.1 %). Genotype III of DENV-3 was first introduced in 2022-2023 in Nepal. Phylogenetic analysis of the E gene revealed the DENV-2 isolates from Nepal had 98 % homologous nucleotide similarity with the strains from India and Bangladesh. To our knowledge, this is the first report of circulating serotypes and genotypes of DENV in Jhapa. Integrating molecular findings into the dengue control plan can enhance surveillance efforts, monitor disease trends, and implement proactive measures to reduce the burden of dengue and prevent fatalities in future outbreaks.
Asunto(s)
Virus del Dengue , Dengue , Brotes de Enfermedades , Genotipo , Filogenia , Serogrupo , Humanos , Virus del Dengue/genética , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Dengue/epidemiología , Dengue/virología , Nepal/epidemiología , Estudios Transversales , Adulto , Masculino , Femenino , Adolescente , Adulto Joven , Persona de Mediana Edad , Niño , Preescolar , Anciano , ARN Viral/genéticaRESUMEN
Dengue viruses are the causative agents of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome, which are mainly transmitted by Aedes aegypti and Aedes albopictus mosquitoes, and cost billions of dollars annually in patient treatment and mosquito control. Progress in understanding DENV pathogenesis and developing effective treatments has been hampered by the lack of a suitable small pathological animal model. Until now, the candidate vaccine, antibody, and drug for DENV have not been effectively evaluated. Here, we analyzed the pathogenicity of DENV-1 in type â and type â ¡ interferon receptor-deficient mice (AGB6) by intraperitoneal inoculation. Infected mice showed such neurological symptoms as opisthotonus, hunching, ataxia, and paralysis of one or both hind limbs. Viremia can be detected 3 days after infection. It was found that 6.98 × 103 PFU or higher dose induce 100% mortality. To determine the cause of lethality in mice, heart, liver, spleen, lung, kidney, intestinal, and brain tissues were collected from AGB6 mice (at an attack dose of 6.98 × 103 PFU) for RNA quantification, and it was found that the viral load in brain tissues peaked at moribund states (14 dpi) and that the viral loads in the other tissues and organs decreased over time. Significant histopathologic changes were observed in brain tissue (hippocampal region and cerebral cortex). Hematological analysis showed hemorrhage and hemoconcentration in infected mice. DENV-1 can be isolated from the brain tissue of infected mice. Subsequently, brain tissue transcriptome sequencing was performed to assess host response characteristics in infected AGB6 mice. Transcriptional patterns in brain tissue suggest that aberrant expression of pro-inflammatory cytokines induces antiviral responses and tissue damage. Screening of hub genes and their characterization by qPCR and ELISA, it was hypothesized that IL-6 and IFN-γ might be the key factors in dengue virus-induced inflammatory response. Therefore, this study provides an opportunity to decipher certain aspects of dengue pathogenesis further and provides a new platform for drug, antibody, and vaccine testing.
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Virus del Dengue , Dengue , Modelos Animales de Enfermedad , Transcriptoma , Carga Viral , Animales , Virus del Dengue/patogenicidad , Virus del Dengue/genética , Dengue/virología , Dengue/inmunología , Ratones , Serogrupo , Perfilación de la Expresión Génica , Encéfalo/virología , Encéfalo/patología , Virulencia , Viremia , Ratones NoqueadosRESUMEN
Porcine circovirus type 2 (PCV2) often causes disease through coinfection with other bacterial pathogens, including Glaesserella parasuis (G. parasuis), which causes high morbidity and mortality, but the role played by PCV2 and bacterial and host factors contributing to this process have not been defined. Bacterial attachment is assumed to occur via specific receptor-ligand interactions between adhesins on the bacterial cell and host proteins adsorbed to the implant surface. Mass spectrometry (MS) analysis of PCV2-infected swine tracheal epithelial cells (STEC) revealed that the expression of Extracellular matrix protein (ECM) Fibronectin (Fn) increased significantly on the infected cells surface. Importantly, efficient G. parasuis serotype 4 (GPS4) adherence to STECs was imparted by interactions with Fn. Furthermore, abrogation of adherence was gained by genetic knockout of Fn, Fn and Integrin ß1 antibody blocking. Fn is frequently exploited as a receptor for bacterial pathogens. To explore the GPS4 adhesin that interacts with Fn, recombinant Fn N-terminal type I and type II domains were incubated with GPS4, and the interacting proteins were pulled down for MS analysis. Here, we show that rare lipoprotein A (RlpA) directly interacts with host Fibronectin mediating GPS4 adhesion. Finally, we found that PCV2-induced Fibronectin expression and adherence of GPS4 were prevented significantly by TGF-ß signaling pathway inhibitor SB431542. Our data suggest the RlpA-Fn interaction to be a potentially promising novel therapeutic target to combat PCV2 and GPS4 coinfection.
Asunto(s)
Circovirus , Fibronectinas , Haemophilus parasuis , Enfermedades de los Porcinos , Tráquea , Animales , Porcinos , Fibronectinas/metabolismo , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/metabolismo , Haemophilus parasuis/metabolismo , Circovirus/metabolismo , Circovirus/patogenicidad , Tráquea/virología , Tráquea/microbiología , Tráquea/metabolismo , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/virología , Infecciones por Haemophilus/metabolismo , Adhesión Bacteriana , Serogrupo , Coinfección/virología , Coinfección/microbiología , Infecciones por Pasteurellaceae/veterinaria , Infecciones por Pasteurellaceae/virología , Infecciones por Pasteurellaceae/microbiología , Infecciones por Pasteurellaceae/metabolismoRESUMEN
Streptococcus pneumoniae, a medically important opportunistic bacterial pathogen of the upper respiratory tract, is a major public health concern, causing a wide range of pneumococcal illnesses, both invasive and noninvasive. It is associated with significant global morbidity and mortality, including pneumonia, meningitis, sepsis, and acute otitis media. The major purpose of this study was to determine the molecular epidemiology of Streptococcus pneumoniae strains that cause invasive and noninvasive infections in Ethiopia. A prospective study was undertaken in two regional hospitals between January 2018 and December 2019. Whole-genome sequencing was used to analyze all isolates. Serotypes and multilocus sequence types (MLST) were derived from genomic data. The E-test was used for antimicrobial susceptibility testing. Patient samples obtained 54 Streptococcus pneumoniae isolates, 33 from invasive and 21 from noninvasive specimens. Our findings identified 32 serotypes expressed by 25 Global Pneumococcal Sequence Clusters (GPSCs) and 42 sequence types (STs), including 21 new STs. The most common sequence types among the invasive isolates were ST3500, ST5368, ST11162, ST15425, ST15555, ST15559, and ST15561 (2/33, 6% each). These sequence types were linked to serotypes 8, 7 C, 15B/C, 16 F, 10 A, 15B, and 6 A, respectively. Among the noninvasive isolates, only ST15432, associated with serotype 23 A, had numerous isolates (4/21, 19%). Serotype 14 was revealed as the most resistant strain to penicillin G, whereas isolates from serotypes 3, 8, 7 C, and 10 A were resistant to erythromycin. Notably, all serotype 6 A isolates were resistant to both erythromycin and penicillin G. Our findings revealed an abnormally significant number of novel STs, as well as extremely diversified serotypes and sequence types, implying that Ethiopia may serve as a breeding ground for novel STs. Recombination can produce novel STs that cause capsular switching. This has the potential to influence how immunization campaigns affect the burden of invasive pneumococcal illness. The findings highlight the importance of continuous genetic surveillance of the pneumococcal population as a vital step toward enhancing future vaccine design.
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Antibacterianos , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Infecciones Neumocócicas , Serogrupo , Streptococcus pneumoniae , Secuenciación Completa del Genoma , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/aislamiento & purificación , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/clasificación , Humanos , Etiopía/epidemiología , Infecciones Neumocócicas/microbiología , Infecciones Neumocócicas/epidemiología , Masculino , Niño , Femenino , Preescolar , Adolescente , Adulto , Persona de Mediana Edad , Estudios Prospectivos , Lactante , Adulto Joven , Antibacterianos/farmacología , AncianoRESUMEN
This study investigated the virulence potential and antibiotic susceptibility analysis of non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups, which are significant cause of food borne diseases. A study collected 800 samples of dairy bovine raw milk through various sources, 500 from milk shops, 200 from dairy farms, 26 from milk collection centers, and 74 from street vendors. Using a standard method, E. coli was detected in 321 out of the 800 samples collected. Out of the 321 E. coli-positive samples isolated, 148 were identified as STEC using selective media, specifically Cefixime Tellurite Sorbitol MacConkey's Agar (CT-SMA). Out of the 148 positive samples, 40 were confirmed as STEC non-O157 strains using multiplex PCR, indicating a prevalence of 5% (40 out of 800 samples). STEC isolates were subjected to antimicrobial susceptibility testing, and all isolates were resistant to at least one or more antimicrobials tested through the disk diffusion method, revealed high resistance to Amoxicillin 100%, Ceftriaxone 50%, and Penicillin 44.5%, and notably 44% of the strains exhibited Streptomycin resistance, while Enrofloxacin 55%, Florfenicol 50% and Norfloxacin 44%, demonstrated the highest susceptibility. Out of 40 STEC non-O157, twelve were subjected to Multi Locus Sequence Typing (MLST) sequencing through Illumina Inc. MiSeq platform's next-generation sequencing technology, United States. The genome investigation evidenced the persistence of twelve serotypes H4:O82, H30:O9a, H4:O82, H16:O187, H9:O9, H16:O113, H30:O9, H32:O, H32:O, H32, H32, and H38:O187, linked to the potential infections in humans. Conclusion: STEC isolates showed resistance to multiple antimicrobials, raising concerns for both animal and public health due to widespread use of these drugs in treatment and prevention. The study contributes new insights into monitoring STEC in raw milk, emphasizing the critical role of whole genome sequencing (WGS) for genotyping and sequencing diverse isolates. Still a deficiency in understanding STEC pathogenesis mechanisms, ongoing surveillance is crucial for safeguarding human health and enhancing understanding of STEC genetic characteristics.
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Antibacterianos , Pruebas de Sensibilidad Microbiana , Leche , Escherichia coli Shiga-Toxigénica , Animales , Bovinos , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/efectos de los fármacos , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Escherichia coli Shiga-Toxigénica/patogenicidad , Leche/microbiología , Antibacterianos/farmacología , Pakistán/epidemiología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/epidemiología , Farmacorresistencia Bacteriana/genética , Secuenciación Completa del Genoma , SerogrupoRESUMEN
BACKGROUND: Dengue is a global public health challenge which requires accurate diagnostic methods for surveillance and control. The gold standard for detecting dengue neutralizing antibodies (nAbs) is the plaque reduction neutralization test (PRNT), which is both labor-intensive and time-consuming. This study aims to evaluate three alternative approaches, namely, the MTT-based (or (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) microneutralization assay, the xCELLigence real-time cell analysis (RTCA), and the immuno-plaque assay-focus reduction neutralization test (iPA-FRNT). METHODS: Twenty-two residual serum samples were tested for DENV-2 nAbs using all four assays at three neutralization endpoints of 50%, 70% and 90% inhibition in virus growth. For each neutralization endpoint, results were compared using linear regression and correlation analyses. Test performance characteristics were further obtained for iPA-FRNT using 38 additional serum samples. RESULTS: Positive correlation of DENV-2 neutralization titers for the MTT-based microneutralization assay and the PRNT assay was only observed at the neutralization endpoint of 50% (r = 0.690). In contrast, at all three neutralization end points, a linear trend and positive correlation of DENV-2 neutralization titers for the xCELLigence RTCA and the PRNT assays were observed, yielding strong or very strong correlation (r = 0.829 to 0.967). This was similarly observed for the iPA-FRNT assay (r = 0.821 to 0.916), which also offered the added advantage of measuring neutralizing titers to non-plaque forming viruses. CONCLUSION: The xCELLigence RTCA and iPA-FRNT assays could serve as suitable alternatives to PRNT for dengue serological testing. The decision to adopt these methods may depend on the laboratory setting, and the utility of additional applications offered by these technologies.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Virus del Dengue , Dengue , Pruebas de Neutralización , Serogrupo , Ensayo de Placa Viral , Virus del Dengue/inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Humanos , Pruebas de Neutralización/métodos , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Ensayo de Placa Viral/métodos , Dengue/inmunología , Dengue/diagnóstico , Dengue/virologíaRESUMEN
BACKGROUND: Pneumococcus is a common cause of pneumonia, meningitis, and other serious infections in children. The previous study has proved that the 13-valent pneumococcal conjugate vaccine (PCV13) has sufficient immunogenicity in children. The data on long-term persistence of immunity will help the follow-up development work of pneumococcal vaccines. METHODS: Children who received the full vaccination course of the tested PCV13 in the previous clinical trial were enrolled again, and these who received other pneumococcal vaccines, or were infected with one or more serotypes of S. pneumoniae corresponding to PCV13 before enrollment were excluded. Participants were divided into four groups by age which is same as that of previous trial. The study lasted for 5 years, during which we measured pneumococcal antibodies of 13 serotypes included in PCV13 at particular points in time. Geometric mean concentrations (GMCs) and seropositive rates (the rate of IgG concentration ≥0.35 µg/mL) of antibodies against 13 serotypes were calculated. RESULTS: For the participants aged 2 months, five years after primary vaccination, except for serotypes 3 and 4, seropositive rates were 100%. GMCs of IgG antibodies against 13 serotypes ranged from 0.733 to 15.160 µg/mL. All of the participants aged 7-11 months had the serotype-specific IgG concentration ≥0.35 µg/mL four years after primary vaccination with the exception of serotypes 3, 4, 6 A and 9 V. IgG GMCs were 0.753-11.031 µg/mL. All participants aged 12-23 months and 2-5 years old had the serotype-specific IgG concentration ≥0.35 µg/mL three or two years after primary vaccination respectively, except for serotype 3. IgG GMCs ranged from 0.815 to 13.111 µg/mL, and 0.684 to 12.282 µg/mL respectively. CONCLUSION: PCV13 was applied to the population aged 2 months and 7 months - 5 years old with a good immune persistence, providing more extensive evidence of long-term efficacy for that vaccine. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov, number NCT06210737.
Asunto(s)
Anticuerpos Antibacterianos , Inmunoglobulina G , Infecciones Neumocócicas , Vacunas Neumococicas , Serogrupo , Streptococcus pneumoniae , Humanos , Vacunas Neumococicas/inmunología , Vacunas Neumococicas/administración & dosificación , Lactante , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Preescolar , Streptococcus pneumoniae/inmunología , Streptococcus pneumoniae/clasificación , Femenino , Masculino , Infecciones Neumocócicas/prevención & control , Infecciones Neumocócicas/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Vacunas Conjugadas/inmunología , Vacunas Conjugadas/administración & dosificación , Vacunación/métodosRESUMEN
Immunity protective against shigella infection targets the bacterial O-specific polysaccharide (OSP) component of lipopolysaccharide. A multivalent shigella vaccine would ideally target the most common global Shigella species and serotypes such as Shigella flexneri 2a, S. flexneri 3a, S. flexneri 6, and S. sonnei. We previously reported development of shigella conjugate vaccines (SCVs) targeting S. flexneri 2a (SCV-Sf2a) and 3a (SCV-Sf3a) using a platform squaric acid chemistry conjugation approach and carrier protein rTTHc, a 52 kDa recombinant protein fragment of the heavy chain of tetanus toxoid. Here we report development of a SCV targeting S. flexneri 6 (SCV-Sf6) using the same platform approach. We demonstrated that SCV-Sf6 was recognized by serotype-specific monoclonal antibodies and convalescent sera of humans recovering from shigellosis in Bangladesh, suggesting correct immunological display of OSP. We vaccinated mice and found induction of serotype-specific OSP and LPS IgG and IgM responses, as well as rTTHc-specific IgG responses. Immune responses were increased when administered with aluminum phosphate adjuvant. Vaccination induced bactericidal antibody responses against S. flexneri 6, and vaccinated animals were protected against lethal challenge with virulent S. flexneri 6. Our results assist in the development of a multivalent vaccine protective against shigellosis.
Asunto(s)
Anticuerpos Antibacterianos , Disentería Bacilar , Inmunoglobulina G , Antígenos O , Vacunas contra la Shigella , Shigella flexneri , Vacunas Conjugadas , Shigella flexneri/inmunología , Animales , Vacunas contra la Shigella/inmunología , Vacunas contra la Shigella/administración & dosificación , Disentería Bacilar/prevención & control , Disentería Bacilar/inmunología , Ratones , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Vacunas Conjugadas/inmunología , Vacunas Conjugadas/administración & dosificación , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Antígenos O/inmunología , Femenino , Ratones Endogámicos BALB C , Inmunoglobulina M/inmunología , Inmunoglobulina M/sangre , Serogrupo , Lipopolisacáridos/inmunologíaRESUMEN
Objective: To describe the profile of Streptococcus pneumoniae, identify research gaps, and provide in-depth insights into various aspects related to the pathogen. Methods: Google Scholar, PubMed, and ScienceDirect were searched for all studies on the pneumococcus in Ghana that reported on specimen collected, population and sample size, carriage prevalence, incidence of pneumococcal diseases, age of the study population, types of test performed, serotypes identified, antimicrobial susceptibilities, or molecular analysis on the pneumococci for data extraction. Results: Overall, a total of 7954 results were obtained from the three-database search, and of this, 24 articles were selected after screening. A total of 924 isolates were accounted for by serotyping/serogrouping. The prevalence of pneumococcal carriage in Ghana ranges from 11.0% to 51.4% in the population depending on the age (≤ 24-80 years), sickle cell disease (SCD), human immunodeficiency virus (HIV) status, or health of the study population, and penicillin (Pen)-nonsusceptible isolates ranged from 17% to 63%. The prevalence of pneumococci found as the etiologic agent of diseases among Ghanaians ranges from 3.4% for otitis media to 77.7% for meningitis. Overall, the 13-valent pneumococcal conjugate vaccine (PCV) (PCV-13) carriage serotypes accounted for 28.4% of the reported pneumococcal isolates. PCV-13 invasive serotypes accounted for 22.4% of the reported isolates. The non-PCV-13 carriage serotypes accounted for most (43.9%) of the reported isolates. In the pre-PCV-13 era, the nontypeable (NT) (5.5%) and other nonvaccine types (NVTs) (6.4%) were reported as being predominant. The non-PCV-13 serotypes accounted for 4.4% of the reported isolates in invasive pneumococcal disease (IPD) cases. Multidrug resistance (MDR) ranged from 7.8% to 100%. Conclusion: Predicting the invasiveness of pneumococci using molecular typing is the way to go in the future as this will provide answers to the extent to which capsular switching is contributing to the pneumococcal disease burden in Ghana almost a decade after introducing PCV-13. Continuous monitoring of antibiotic resistance patterns at both phenotypic and genotypic levels, along with serotyping and molecular typing, should be a standard practice in the surveillance of pneumococcal disease burden in Ghana.
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Infecciones Neumocócicas , Vacunas Neumococicas , Streptococcus pneumoniae , Humanos , Ghana/epidemiología , Streptococcus pneumoniae/patogenicidad , Streptococcus pneumoniae/aislamiento & purificación , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/microbiología , Prevalencia , Serogrupo , Adulto , Anciano , Persona de Mediana Edad , Anciano de 80 o más Años , Serotipificación , Femenino , Antibacterianos/farmacología , Antibacterianos/uso terapéuticoRESUMEN
Streptococcus agalactiae (S. agalactiae) is an opportunistic pathogen, and to date, studies have mainly focused on S. agalactiae strains isolated from humans, dairy cows, and fish. We reported one S. agalactiae strain, named CFFB, which was isolated from a healthy Sichuan golden snub-nosed monkey. Classical bacteriological approaches, as well as, next-generation sequencing, comparative genomics, and mice challenge test were used to characterize this strain. CFFB was identified as serotype III, ST19 combination which is a common type found in human strains. Phylogenetic analysis showed that the genome of CFFB was closely related to human clinical isolates, rather far away from animal strains. In total, CFFB contained fewer virulence-associated genes and antibiotic resistance genes than human isolates that were close to CFFB in evolutionary relationships. In the mice challenge test, CFFB had a relative weak virulence that just caused death in 33 % of ICR mice at a dose of 108 CFU by intraperitoneal injection, and CFFB was reisolated from the cardiac blood of the dead mice. Meanwhile, two intact prophages (prophage 1 and 2) were identified in the CFFB genome and shared high similarities with phage Javan52 and Javan29 which from human S. agalactiae isolate Gottschalk 1002A and RBH03, respectively. Moreover, the type II-A CRISPR-Cas system was detected in the CFFB genome, and the spacers from CFFB were the same to the streptococci isolates from human. These results suggest that CFFB isolated from healthy Sichuan golden snub-nosed monkeys may have its origin in human S. agalactiae. Our results suggested some genomic similarities between the S. agalactiae colonized in Sichuan golden snub-nosed monkey and those in infected humans.
Asunto(s)
Genoma Bacteriano , Filogenia , Infecciones Estreptocócicas , Streptococcus agalactiae , Animales , Streptococcus agalactiae/genética , Streptococcus agalactiae/aislamiento & purificación , Streptococcus agalactiae/patogenicidad , Infecciones Estreptocócicas/microbiología , Infecciones Estreptocócicas/veterinaria , China , Virulencia/genética , Ratones , Colobinae/microbiología , Humanos , Profagos/genética , Ratones Endogámicos ICR , Factores de Virulencia/genética , Serogrupo , Secuenciación de Nucleótidos de Alto Rendimiento , Enfermedades de los Monos/microbiologíaRESUMEN
BACKGROUND: Streptococcus pneumoniae, a major contributor to global morbidity and mortality, disproportionately affects children, the elderly, and immunocompromised individuals. Despite vaccination efforts, the challenge of serotype replacement highlights the ongoing struggle against invasive pneumococcal diseases (IPD) in Morocco, emphasizing the need for updated public health strategies and vaccine efficacy assessments. METHODS: This study was conducted at the Ibn Rochd University Hospital Center and the Mohammed VI University Hospital Center from 2019 to 2022, focusing on hospitalized children. It involved the analysis of 74 strains of IPD, assessing the distribution of pneumococcal serotypes and their antibiotic sensitivity in the post-vaccination era. RESULTS: The prevalence of meningitis or meningo-encephalitis was found to be 66% among the study subjects, with the most frequent serotypes being 3, 19A, 6B, 14, and 11. These serotypes varied significantly by age and location. Coverage rates for the pneumococcal conjugate vaccines, PCV-10 and PCV-13, were 20.27% and 56.75%, respectively. Notably, 43% of the strains were non-vaccine serotypes, with serotypes 3 and 19 accounting for 36% of the infections in children, indicating a lack of vaccine efficacy against these types. Additionally, 31.3% of the strains were Penicillin non-susceptible Streptococcus pneumoniae (PNSP), with 81.25% associated with non-vaccine serotypes. CONCLUSIONS: This study highlights the persistence of IPD in Moroccan children, revealing significant challenges despite vaccination efforts. With the reintroduction of PCV-13, concerns about the efficacy against non-vaccine serotypes, particularly 3 and 19A, remain. Continuous surveillance and adaptable vaccination strategies are essential to combat these serotype replacements and ensure the effectiveness of future preventive measures.
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Infecciones Neumocócicas , Vacunas Neumococicas , Serogrupo , Streptococcus pneumoniae , Humanos , Marruecos/epidemiología , Vacunas Neumococicas/administración & dosificación , Vacunas Neumococicas/inmunología , Infecciones Neumocócicas/prevención & control , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/microbiología , Preescolar , Streptococcus pneumoniae/inmunología , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/aislamiento & purificación , Lactante , Niño , Masculino , Femenino , Vacunación/estadística & datos numéricos , Adolescente , Antibacterianos/uso terapéutico , PrevalenciaRESUMEN
Adeno-associated viruses (AAVs) have emerged as a prominent family of vectors for gene delivery, providing therapeutic options to diseases once deemed incurable. At the same time, they necessitate efficient and affordable purification methods that can be platformed to serve all AAV serotypes. Current chromatographic tools, while affording high product purity, fail to bind certain serotypes, provide limited yield and lifetime, and impose harsh elution conditions that can compromise the vector's activity and safety. Addressing these challenges, this work demonstrates the application of new peptide ligands as the first serotype-agnostic technology for AAV purification by affinity chromatography. Our study reveals a pH-dependent affinity interaction: AAV2, AAV3, AAV6, AAV9, and AAVrh.10 are effectively captured at neutral pH, while binding AAV1, AAV5, AAV7, and AAV8 is stronger in a slightly acidic environment. The elution of bound AAVs was achieved using magnesium chloride at neutral pH for all serotypes, consistently affording capsid yields above 50% and genome yields above 80%, together with a >100-fold reduction in host cell proteins and nucleic acids. In particular, peptide ligand A10 exhibited remarkable binding capacity (> 1014 vp per mL of resin) and purification performance for all AAV serotypes, demonstrating broad applicability for gene therapy manufacturing. Finally, this work introduces novel alkaline-stable variants of A10 and demonstrates their use as the first affinity ligands capable of performing multiple cycles of AAV2, AAV8, and AAV9 purification with intermediate caustic cleaning without loss of capacity or product quality. Collectively, these results demonstrate the promise of this technology to further the impact and affordability of gene therapy.
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Cromatografía de Afinidad , Dependovirus , Péptidos , Serogrupo , Dependovirus/aislamiento & purificación , Dependovirus/genética , Dependovirus/química , Cromatografía de Afinidad/métodos , Péptidos/química , Péptidos/aislamiento & purificación , Humanos , Concentración de Iones de Hidrógeno , Vectores Genéticos , Células HEK293RESUMEN
INTRODUCTION: In 2005, the United States Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination against invasive meningococcal disease (IMD) caused by serogroups A, C, W, and Y (MenACWY) for all 11-12-year-olds, as well as 2-10-year-olds at high risk. In 2010, a booster dose was recommended for all 16-year-olds, as well as for high-risk patients every 3-5 years. In 2015, optional (as opposed to routine) vaccination against meningococcal serogroup B (MenB) at the preferred age of 16-18 years was recommended (Category B, later changed to shared clinical decision-making). In 2023, a vaccine (MenABCWY) against the five serogroups primarily responsible for IMD in the U.S. became available. AREAS COVERED: This review summarizes the evolution of public policy that led to each milestone vaccine recommendation, reviews epidemiologic data published following the recommendations, and discusses the current state of meningococcal immunization policy. EXPERT OPINION: The use of MenABCWY has the potential to consolidate policy, improve coverage rates for the five serogroups, address disparities in vaccination coverage, and simplify vaccine delivery.
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Política de Salud , Infecciones Meningocócicas , Vacunas Meningococicas , Vacunación , Humanos , Vacunas Meningococicas/administración & dosificación , Vacunas Meningococicas/inmunología , Estados Unidos/epidemiología , Infecciones Meningocócicas/prevención & control , Infecciones Meningocócicas/epidemiología , Vacunación/métodos , Adolescente , Niño , Preescolar , Serogrupo , Esquemas de Inmunización , Neisseria meningitidis/inmunologíaRESUMEN
Several authors have attributed the explosive outbreak of gastroenteritis that occurred in Czechoslovakia in 1965 to a toxigenic strain of Vibrio cholerae serogroup O37 based on unverified metadata associated with three particular strains from the American Type Culture Collection. Here, by sequencing the original strain preserved at the Czech National Collection of Type Cultures since 1966, we show that the strain responsible for this outbreak was actually a V. cholerae O5 that lacks the genes encoding the cholera toxin, the toxin-coregulated pilus protein and Vibrio pathogenicity islands present in V. cholerae O37 strains.
Asunto(s)
Cólera , Brotes de Enfermedades , Gastroenteritis , Vibrio cholerae , Gastroenteritis/microbiología , Gastroenteritis/epidemiología , Gastroenteritis/historia , Humanos , Vibrio cholerae/genética , Vibrio cholerae/clasificación , Checoslovaquia , Cólera/epidemiología , Cólera/microbiología , Cólera/historia , Toxina del Cólera/genética , Islas Genómicas , SerogrupoRESUMEN
Vibrio parahaemolyticus, an important food-borne pathogens found to be associated with seafoods and marine environs. It has been a topic of debate for many decades that most pathogens are known to enter a viable but nonculturable (VBNC) state under cold temperature and nutrient limited conditions. The present study examined the time required for the induction of VBNC state and the revival strategies of both the endemic O3:K6 and O1:K25 sporadic strains of V. parahaemolyticus. The results revealed that V. parahaemolyticus survived even after 55 days of incubation in nutrient starved media such as phosphate buffered saline (PBS) and Coastal Water (CW) and could be recovered by temperature upshift method, and compared the resuscitation using Dulbecco's Modified Eagle Medium (DMEM), sheep blood serum, chitin flakes with live Artemia salina, and the results suggests that chitin plays a significant role in regulating the VBNC state. It was also confirmed by Confocal Laser Scanning Microscopy (CLSM) and Scanning Electron Microscope (SEM) analysis that VBNC cells can alter their morphology to coccoid forms in order to survive in most extreme nutrient limited environment. Further data on the promoting factors and the exact mechanism that resuscitate VBNC V. parahaemolyticus in cold natural environments and frozen foods are needed to perform a robust risk assessment.
Asunto(s)
Medios de Cultivo , Viabilidad Microbiana , Vibrio parahaemolyticus , Vibrio parahaemolyticus/crecimiento & desarrollo , Animales , Medios de Cultivo/química , Serogrupo , Frío , Microbiología de Alimentos , Artemia/microbiología , Alimentos Marinos/microbiologíaRESUMEN
Leptospirosis, a neglected zoonotic disease, adversely affects animal, human health, and socioeconomic conditions, particularly in developing countries like Nigeria. This study aimed to determine the occurrence and molecular identification of pathogenic Leptospira spp. among abattoir workers, cattle, and rats in Jos North, Plateau State, Nigeria. Using a cross-sectional study design, a total of 394 samples were collected, including 149 urine samples from abattoir workers, 125 urine samples from cattle bladders, and 120 bladders from trapped rats. Samples were processed and cultured in Ellinghausen McCullough Johnson Harrison (EMJH) medium and examined under a darkfield microscope. Positive cultures were confirmed using the Microscopic Agglutination Test (MAT) and nested Polymerase Chain Reaction (N-PCR) targeted the 16â¯S rDNA gene. Results revealed a prevalence of 33.76â¯% for Leptospira spp. across all samples, with the highest occurrence in abattoir workers (13.96â¯%), followed by rats (13.45â¯%), and cattle (6.35â¯%). The MAT showed L. interrogans serovar Hardjo str. Hardjoprajitno as the most prevalent serotype (41.61â¯%), followed by L. interrogans serovar Icterohaemorrhagiae str. RGA (34.31â¯%). N-PCR confirmed the presence of pathogenic Leptospira spp., showing bands of 1200â¯bp. Phylogenetic analysis of the 16â¯S rDNA gene sequences revealed close similarities to known pathogenic Leptospira strains from Brazil and the USA. The study underscores the significant public health risk posed by leptospirosis in Jos North and highlights the need for improved diagnostic capabilities, increased awareness, and effective control measures to mitigate the disease burden. Enhanced surveillance and preventive strategies are crucial to protect both animal and human health in the region.
Asunto(s)
Mataderos , Leptospira interrogans , Leptospirosis , Animales , Nigeria/epidemiología , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/veterinaria , Bovinos , Ratas , Estudios Transversales , Leptospira interrogans/genética , Leptospira interrogans/aislamiento & purificación , Humanos , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/epidemiología , Prevalencia , Masculino , Reacción en Cadena de la Polimerasa , Pruebas de Aglutinación , Serogrupo , Filogenia , FemeninoRESUMEN
We determined the dengue virus (DENV) serotypes and genotypes in archived serum samples that were collected during the 2014-2016 and 2021 dengue outbreaks in Dire Dawa City and the Somali region in Ethiopia. DENV serotype 1 (DENV-1) was predominant followed by DENV serotype 2 (DENV-2). Thirteen of the DENV-1 strains were assigned to Genotype-I, while the remaining two were found to be Genotype-III. All three DENV-2 strains were assigned the Cosmopolitan Genotype. The DENV strains responsible for the outbreaks are genetically closely related to the DENV strains that circulated in neighboring and Asian countries. The findings also showed continued local transmission of a monophyletic lineage and a co-circulation of DENV-1 and DENV-2 during the outbreaks. There is a need to strengthen DENV genomic surveillance capacity for the early detection of circulating serotypes, and prevent devastating consequences of future outbreaks due to the co-circulation of different serotypes.
Asunto(s)
Virus del Dengue , Dengue , Brotes de Enfermedades , Genotipo , Filogenia , Serogrupo , Virus del Dengue/genética , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Etiopía/epidemiología , Humanos , Dengue/epidemiología , Dengue/virología , Femenino , Masculino , Adulto , Adolescente , Adulto Joven , Niño , ARN Viral/genética , Persona de Mediana EdadRESUMEN
Here, we characterize the complete genome sequence of Escherichia coli isolated from a newborn affected by bacterial meningitis in Italy. Genome of E. coli strain 1455 harbored a circular chromosome and two plasmids of 167.740-bp and 4.073-bp in length, respectively. E. coli 1455 belonged to the ST3, serotype O17:H18 and carried different determinants including resistance to B-lactams, tetracyclines, and quinolones. In addition, genome of E. coli strain 1455 harbored 5 integrated pro-phage regions mainly located in the chromosome, while most of the virulence factors associated to the invasiveness and clinical severity and different antimicrobial resistance determinants (blaTEM-1, tet(A) and qnrS1) were located in the 167-Kb plasmid. Taken together, our findings suggest a possible widespread of a virulence factors-carrying plasmid worldwide and highlight the importance of genomic characterization in the diffusion of public health threats.
Asunto(s)
Escherichia coli , Genoma Bacteriano , Meningitis por Escherichia coli , Plásmidos , Factores de Virulencia , Recién Nacido , Italia , Humanos , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Escherichia coli/patogenicidad , Escherichia coli/clasificación , Genoma Bacteriano/genética , Factores de Virulencia/genética , Plásmidos/genética , Meningitis por Escherichia coli/microbiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Secuenciación Completa del Genoma , Meningitis Bacterianas/microbiología , Serogrupo , Pruebas de Sensibilidad Microbiana , GenómicaRESUMEN
Streptococcus pneumoniae carriage studies are crucial to monitor changes induced by use of pneumococcal conjugate vaccines and inform vaccination policies. In this cross-sectional study, we examined changes within the pneumococcal population following introduction of PCV13 in 2015 in the National Immunization Program (NIP), in Portugal. In 2018-2020 (NIP-PCV13), we obtained 1450 nasopharyngeal samples from children ≤6 years attending day-care. We assessed serotypes, antimicrobial resistance, and genotypes (MLST and GPSC) and compared findings with earlier periods: 2009-2010 (pre-PCV13), 2011-2012 (early-PCV13), and 2015-2016 (late-PCV13). Pneumococcal carriage prevalence remained stable at 60.2 %. Carriage of PCV13 serotypes was 10.7 %, markedly reduced compared to pre-PCV13 period (47.6 %). The most prevalent PCV13 serotypes were 19F, 3, and 19A all showing a significant decreasing trend compared to the pre-PCV13 period (from 7.1 % to 4.7 %, 10.1 % to 1.8 %, and 14.1 % to 1.8 %, respectively), a notable observation given the described limited effectiveness of PCV13 against serotype 3. Non-vaccinated children and children aged 4-6 years were more likely to carry PCV13 serotypes (2.5-fold, 95 %CI [1.1-5.6], and 2.9-fold, 95 %CI [1.3-6.8], respectively). The most prevalent non-PCV13 serotypes were 15B/C, 11A, 23B, 23A, and NT, collectively accounting for 51.9 % of all isolates. In total, 30.5 % of all pneumococci were potentially covered by PCV20. Resistance to penicillin (low-level) and macrolides increased significantly, from 9.3 % and 13.4 %, respectively, in the late-PCV13 period, to approximately 20 % each, mostly due to lineages expressing non-PCV13 serotypes, nearing pre-PCV13 levels. An expansion of lineages traditionally associated with PCV13 serotypes, like CC156-GPSC6 (serotype 14) and CC193-GPSC11 (serotype 19F), but now predominantly expressing non-PCV13 serotypes (11A, 15B/C, and 24F for GPSC6; and 15A and 21 for GPSC11) was noted. These findings indicate that the pneumococcal population is adapting to the pressures conferred by PCV13 and antimicrobial use and indicate the need to maintain close surveillance.
Asunto(s)
Portador Sano , Genotipo , Programas de Inmunización , Nasofaringe , Infecciones Neumocócicas , Vacunas Neumococicas , Serogrupo , Streptococcus pneumoniae , Humanos , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/inmunología , Vacunas Neumococicas/inmunología , Vacunas Neumococicas/administración & dosificación , Estudios Transversales , Portugal/epidemiología , Preescolar , Infecciones Neumocócicas/prevención & control , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/microbiología , Femenino , Masculino , Portador Sano/epidemiología , Portador Sano/microbiología , Lactante , Nasofaringe/microbiología , Niño , Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Prevalencia , Vacunas Conjugadas/inmunología , Vacunas Conjugadas/administración & dosificación , Pruebas de Sensibilidad MicrobianaRESUMEN
Dengue, caused by the dengue virus (DENV), is a global health threat transmitted by Aedes mosquitoes, resulting in 400 million cases annually. The disease ranges from mild to severe, with potential progression to hemorrhagic dengue. Current research is focused on natural antivirals due to challenges in vector control. This study evaluates the antiviral potential of peptides derived from the microalgae Phaeodactylum tricornutum, known for its bioactive compounds. Microalgae were cultivated under controlled conditions, followed by protein extraction and hydrolysis to produce four peptide fractions. These fractions were assessed for cytotoxicity via the MTT assay and antiviral activity against DENV serotype 2 using flow cytometry and plaque formation assays. The 10-30 kDa peptide fraction, at 150 and 300 µg/mL concentrations, demonstrated no cytotoxicity and significantly reduced the percentage of infected cells and viral titers. These findings suggest that peptides derived from Phaeodactylum tricornutum exhibit promising antiviral activity against dengue virus serotype 2, potentially contributing to developing new therapeutic approaches for dengue.