RESUMEN
INTRODUCTION: The object of this study was to evaluate the primary stability of tibial interference screw (IFS) fixation in single-stage revision surgery of the anterior cruciate ligament (ACL) in the case of recurrent instability after ACL repair with dynamic intraligamentary stabilization (DIS), dependent on the implant position during DIS. MATERIALS AND METHODS: Tibial aperture fixation in ACL reconstruction (ACL-R) was performed in a porcine knee model using an IFS. Native ACL-R was performed in the control group (n = 15). In the intervention groups DIS and subsequent implant removal were performed prior to single-stage revision ACL-R. A distance of 20 mm in group R-DIS1 (n = 15) and 5 mm in group R-DIS2 (n = 15) was left between the joint line and the implant during DIS. Specimens were mounted in a material-testing machine and load-to-failure was applied in a worst-case-scenario. RESULTS: Load to failure was 454 ± 111 N in the R-DIS1 group, 154 ± 71 N in the R-DIS2 group and 405 ± 105 N in the primary ACL-R group. Load-to-failure, stiffness and elongation of the group R-DIS2 were significantly inferior in comparison to R-DIS1 and ACL-R respectively (p < 0.001). No significant difference was found between load-to-failure, stiffness and elongation of R-DIS1 and the control group. CONCLUSION: Primary stability of tibial aperture fixation in single-stage revision ACL-R in case of recurrent instability after DIS depends on monobloc position during ACL repair. Primary stability is comparable to aperture fixation in primary ACL-R, if a bone stock of 20 mm is left between the monobloc and the tibial joint line during the initial procedure.
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Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Animales , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Tornillos Óseos , Humanos , Articulación de la Rodilla/cirugía , PorcinosRESUMEN
This article reports a case of a bilateral well leg compartment syndrome (WLCS) in a 9-year-old girl who presented to the emergency room 24â¯h after blunt abdominal trauma and liver laceration. The abdomen was already packed on presentation. The patient presented a manifest compartment syndrome of both lower legs 48â¯h after the second look surgery and removal of the packing. Both tibial anterior and peroneal compartments had to be partially resected. In an analysis of literature only five cases of WLCS after surgery in a supine position were found. The young age of the patient and the intra-abdominal packing were identified as risk factors for increased intra-abdominal pressure and reperfusion was suspected to be the cause of the lower leg compartment syndrome.
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Síndromes Compartimentales , Celulitis (Flemón) , Niño , Fasciotomía , Femenino , Humanos , Pierna , Extremidad Inferior , Complicaciones PosoperatoriasRESUMEN
AIMS/HYPOTHESIS: Viruses are candidate causative agents in the pathogenesis of autoimmune (type 1) diabetes. We hypothesised that children with a rapid onset of type 1 diabetes may have been exposed to such agents shortly before the initiation of islet autoimmunity, possibly at high dose, and thus study of these children could help identify viruses involved in the development of autoimmune diabetes. METHODS: We used next-generation sequencing to search for viruses in plasma samples and examined the history of infection and fever in children enrolled in The Environmental Determinants of Diabetes in the Young (TEDDY) study who progressed to type 1 diabetes within 6 months from the appearance of islet autoimmunity, and in matched islet-autoantibody-negative controls. RESULTS: Viruses were not detected more frequently in plasma from rapid-onset patients than in controls during the period surrounding seroconversion. In addition, infection histories were found to be similar between children with rapid-onset diabetes and control children, although episodes of fever were reported less frequently in children with rapid-onset diabetes. CONCLUSIONS/INTERPRETATION: These findings do not support the presence of viraemia around the time of seroconversion in young children with rapid-onset type 1 diabetes.
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Diabetes Mellitus Tipo 1/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Virus/genética , Autoinmunidad/genética , Autoinmunidad/inmunología , Preescolar , Diabetes Mellitus Tipo 1/virología , Femenino , Humanos , Lactante , Recién Nacido , Islotes Pancreáticos/inmunología , Islotes Pancreáticos/metabolismo , Masculino , Virosis/genéticaRESUMEN
In 1983, reports of antibodies in subjects with major depressive disorder (MDD) to an as-yet uncharacterized infectious agent associated with meningoencephalitis in horses and sheep led to molecular cloning of the genome of a novel, negative-stranded neurotropic virus, Borna disease virus (BDV). This advance has enabled the development of new diagnostic assays, including in situ hybridization, PCR and serology based on recombinant proteins. Since these assays were first implemented in 1990, more than 80 studies have reported an association between BDV and a wide range of human illnesses that include MDD, bipolar disorder (BD), schizophrenia (SZ), anxiety disorder, chronic fatigue syndrome, multiple sclerosis, amyotrophic lateral sclerosis, dementia and glioblastoma multiforme. However, to date there has been no blinded case-control study of the epidemiology of BDV infection. Here, in a United States-based, multi-center, yoked case-control study with standardized methods for clinical assessment and blinded serological and molecular analysis, we report the absence of association of psychiatric illness with antibodies to BDV or with BDV nucleic acids in serially collected serum and white blood cell samples from 396 subjects, a study population comprised of 198 matched pairs of patients and healthy controls (52 SZ/control pairs, 66 BD/control pairs and 80 MDD/control pairs). Our results argue strongly against a role for BDV in the pathogenesis of these psychiatric disorders.
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Trastorno Bipolar/virología , Virus de la Enfermedad de Borna/inmunología , Trastorno Depresivo Mayor/virología , Esquizofrenia/virología , Adulto , Anciano , Anticuerpos Antivirales/sangre , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , ARN Viral/sangreRESUMEN
The COVID-19 pandemic exposed global vulnerabilities to emerging infectious diseases, heralded by earlier outbreaks, that did not result in appropriate investments in surveillance, international collaboration, and response. We propose specific steps that should be taken to reduce future risks to public health, economic and political stability, and food security.
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COVID-19 , Pandemias , COVID-19/epidemiología , Salud Global , Humanos , Sistema Inmunológico , Cooperación Internacional , Pandemias/prevención & controlRESUMEN
Israel acute paralysis virus (IAPV) is associated with colony collapse disorder of honey bees. Nonetheless, its role in the pathogenesis of the disorder and its geographic distribution are unclear. Here, we report phylogenetic analysis of IAPV obtained from bees in the United States, Canada, Australia, and Israel and the establishment of diagnostic real-time PCR assays for IAPV detection. Our data indicate the existence of at least three distinct IAPV lineages, two of them circulating in the United States. Analysis of representatives from each proposed lineage suggested the possibility of recombination events and revealed differences in coding sequences that may have implications for virulence.
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Abejas/virología , Demografía , Filogenia , Picornaviridae/genética , Picornaviridae/fisiología , Animales , Australia , Secuencia de Bases , Análisis por Conglomerados , Cartilla de ADN/genética , Israel , Datos de Secuencia Molecular , América del Norte , Alineación de Secuencia , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
In March and April 2009, a new strain of influenza A(H1N1) virus has been isolated in Mexico and the United States. Since the initial reports more than 10,000 cases have been reported to the World Health Organization, all around the world. Several hundred isolates have already been sequenced and deposited in public databases. We have studied the genetics of the new strain and identified its closest relatives through a cluster analysis approach. We show that the new virus combines genetic information related to different swine influenza viruses. Segments PB2, PB1, PA, HA, NP and NS are related to swine H1N2 and H3N2 influenza viruses isolated in North America. Segments NA and M are related to swine influenza viruses isolated in Eurasia.
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Trazado de Contacto/métodos , Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/virología , ARN Viral/análisis , Secuencia de Bases/genética , Análisis por Conglomerados , Humanos , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , México/epidemiología , ARN Viral/genética , Estados Unidos/epidemiologíaRESUMEN
Infectious viruses so precisely fit their hosts that the study of natural viral infection depends on host-specific mechanisms that affect viral infection. For human parainfluenza virus 3, a prevalent cause of lower respiratory tract disease in infants, circulating human viruses are genetically different from viruses grown in standard laboratory conditions; the surface glycoproteins that mediate host cell entry on circulating viruses are suited to the environment of the human lung and differ from those of viruses grown in cultured cells. Polarized human airway epithelium cultures have been used to represent the large, proximal airways of mature adult airways. Here we modeled respiratory virus infections that occur in children or infect the distal lung using lung organoids that represent the entire developing infant lung. These 3D lung organoids derived from human pluripotent stem cells contain mesoderm and pulmonary endoderm and develop into branching airway and alveolar structures. Whole-genome sequencing analysis of parainfluenza viruses replicating in the organoids showed maintenance of nucleotide identity, suggesting that no selective pressure is exerted on the virus in this tissue. Infection with parainfluenza virus led to viral shedding without morphological changes, while respiratory syncytial virus infection induced detachment and shedding of infected cells into the lung organoid lumens, reminiscent of parainfluenza and respiratory syncytial virus in human infant lungs. Measles virus infection, in contrast, induced syncytium formation. These human stem cell-derived lung organoids may serve as an authentic model for respiratory viral pathogenesis in the developing or infant lung, recapitulating respiratory viral infection in the host.IMPORTANCE Respiratory viruses are among the first pathogens encountered by young children, and the significant impact of these viral infections on the developing lung is poorly understood. Circulating viruses are suited to the environment of the human lung and are different from those of viruses grown in cultured cells. We modeled respiratory virus infections that occur in children or infect the distal lung using lung organoids that represent the entire developing infant lung. These 3D lung organoids, derived from human pluripotent stem cells, develop into branching airway and alveolar structures and provide a tissue environment that maintains the authentic viral genome. The lung organoids can be genetically engineered prior to differentiation, thereby generating tissues bearing or lacking specific features that may be relevant to viral infection, a feature that may have utility for the study of host-pathogen interaction for a range of lung pathogens.
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Células Epiteliales Alveolares/virología , Pulmón/virología , Organoides/virología , Virus de la Parainfluenza 3 Humana/patogenicidad , Células Madre Pluripotentes/virología , Infecciones por Respirovirus/patología , Diferenciación Celular , Células Cultivadas , Genoma Viral , Humanos , Lactante , Pulmón/citología , Pulmón/patología , Virus del Sarampión/patogenicidad , Virus de la Parainfluenza 3 Humana/genética , Virus Sincitial Respiratorio Humano/patogenicidad , Internalización del Virus , Secuenciación Completa del GenomaRESUMEN
Hypothesized risk factors for psychostimulant, amphetamine, and cocaine abuse include dopamine (DA) receptor polymorphisms, HIV infection, schizophrenia, drug-induced paranoias, and movement disorders; however, the molecular, cellular, and biochemical mechanisms that predispose to drug sensitivity or drive the development of addiction are incompletely understood. Using the Borna disease rat, an animal model of viral-induced encephalopathy wherein sensitivity to the locomotor and stereotypic behavioral effects of d-amphetamine and cocaine is enhanced (Solbrig et al., 1994, 1998), we identify a specific neurotrophin expression pattern triggered by striatal viral injury that increases tyrosine hydroxylase activity, an early step in DA synthesis, to produce a phenotype of enhanced amphetamine sensitivity. The reactive neurotrophin pattern provides a molecular framework for understanding how CNS viral injury, as well as other CNS adaptations producing similar growth factor activation profiles, may influence psychostimulant sensitivity.
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Enfermedad de Borna/metabolismo , Encéfalo/metabolismo , Factores de Crecimiento Nervioso/biosíntesis , Trastornos Relacionados con Sustancias/metabolismo , Animales , Western Blotting , Virus de la Enfermedad de Borna/patogenicidad , Encéfalo/efectos de los fármacos , Encéfalo/patología , Encéfalo/virología , Química Encefálica , Estimulantes del Sistema Nervioso Central/farmacología , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Cuerpo Estriado/ultraestructura , Cuerpo Estriado/virología , Dextroanfetamina/farmacología , Susceptibilidad a Enfermedades/virología , Relación Dosis-Respuesta a Droga , Masculino , Actividad Motora/efectos de los fármacos , Fosforilación , Pruebas de Precipitina , Ratas , Ratas Endogámicas Lew , Tirosina 3-Monooxigenasa/análisis , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Despite progress in understanding the molecular biology and pathobiology of Borna disease virus, its epidemiology and role in human disease remain controversial. The challenges encountered in this field are a paradigm for the investigation of diseases potentially linked to complex host-microorganism interactions.
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Enfermedad de Borna/virología , Virus de la Enfermedad de Borna/fisiología , Trastornos Mentales/virología , Animales , Enfermedad de Borna/complicaciones , Enfermedad de Borna/diagnóstico , Enfermedad de Borna/epidemiología , Enfermedad de Borna/transmisión , Humanos , Leucocitos Mononucleares/virologíaRESUMEN
Four out of the five high molecular weight penicillin-binding proteins (PBPs) of Streptococcus pneumoniae are involved in the development of intrinsic penicillin resistance. In beta-lactam resistant laboratory mutants, point mutations in the PBP 2x-genes were identified that result in low penicillin-affinity mutant proteins. In contrast, PBPs 1a, 2x, and 2b of resistant clinical isolates are highly altered as can be recognized biochemically and immunologically; DNA sequence analysis of the PBP 2x gene from resistant strains confirmed these results. The variability of the three PBPs analyzed implies a very heterogeneous gene pool accessible to the pneumococcus that is used for recruitment of resistant PBP genes in wild type strains.
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Proteínas Bacterianas , Proteínas Portadoras/metabolismo , Hexosiltransferasas , Muramoilpentapéptido Carboxipeptidasa/metabolismo , Peptidil Transferasas , Streptococcus pneumoniae/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Proteínas Portadoras/química , Proteínas Portadoras/genética , Cefotaxima/farmacología , Escherichia coli , Muramoilpentapéptido Carboxipeptidasa/química , Muramoilpentapéptido Carboxipeptidasa/genética , Mutación/genética , Resistencia a las Penicilinas , Proteínas de Unión a las PenicilinasRESUMEN
West Nile virus (WNV) first emerged in the US in 1999 and has since spread across the Americas. Here, we report the continued expansion of WNV to the British Virgin Islands following its emergence in a flock of free-roaming flamingos. Histologic review of a single chick revealed lesions consistent with WNV infection, subsequently confirmed with PCR, immunohistochemistry and in situ hybridization. Full genome analysis revealed 99% sequence homology to strains circulating in the US over the past decade. This study highlights the need for rapid necropsy of wild bird carcasses to fully understand the impact of WNV on wild populations.
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Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/virología , Culex/virología , Brotes de Enfermedades/veterinaria , Insectos Vectores/virología , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/aislamiento & purificación , Animales , Animales Salvajes/virología , Enfermedades de las Aves/transmisión , Aves/virología , Mordeduras y Picaduras/virología , Islas Vírgenes Británicas , Inmunohistoquímica , Hibridación in Situ , Reacción en Cadena de la Polimerasa , Fiebre del Nilo Occidental/transmisión , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/genéticaRESUMEN
The family Rhabdoviridae is a diverse group of non-segmented, negative-sense RNA viruses that are distributed worldwide and infect a wide range of hosts including vertebrates, invertebrates, and plants. Of the 114 currently recognized vertebrate rhabdoviruses, relatively few have been well characterized at both the antigenic and genetic level; hence, the phylogenetic relationships between many of the vertebrate rhabdoviruses remain unknown. The present report describes a novel rhabdovirus isolated from the brain of a moribund American coot (Fulica americana) that exhibited neurological signs when found in Durham County, North Carolina, in 2005. Antigenic characterization of the virus revealed that it was serologically unrelated to 68 other known vertebrate rhabdoviruses. Genomic sequencing of the virus indicated that it shared the highest identity to Tupaia rhabdovirus (TUPV), and as only previously observed in TUPV, the genome encoded a putative C protein in an overlapping open reading frame (ORF) of the phosphoprotein gene and a small hydrophobic (SH) protein located in a novel ORF between the matrix and glycoprotein genes. Phylogenetic analysis of partial amino acid sequences of the nucleoprotein and polymerase protein indicated that, in addition to TUPV, the virus was most closely related to avian and small mammal rhabdoviruses from Africa and North America. In this report, we present the morphological, pathological, antigenic, and genetic characterization of the new virus, tentatively named Durham virus (DURV), and discuss its potential evolutionary relationship to other vertebrate rhabdoviruses.
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Aves/virología , Rhabdoviridae/genética , Rhabdoviridae/patogenicidad , Proteínas Virales/genética , Estructuras Animales/patología , Animales , Animales Recién Nacidos , Encéfalo/virología , Análisis por Conglomerados , Orden Génico , Histocitoquímica , Inmunohistoquímica , Ratones , Ratones Endogámicos ICR , Microscopía , Microscopía Electrónica de Transmisión , Datos de Secuencia Molecular , North Carolina , Filogenia , ARN Viral/genética , Rhabdoviridae/aislamiento & purificación , Rhabdoviridae/ultraestructura , Infecciones por Rhabdoviridae/patología , Infecciones por Rhabdoviridae/virología , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Virión/ultraestructuraAsunto(s)
Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental , Amidas , Animales , Antivirales/farmacología , Antivirales/uso terapéutico , Encéfalo/virología , Brotes de Enfermedades , Genoma Viral , Humanos , Ciudad de Nueva York/epidemiología , Pirazoles , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribavirina/farmacología , Ribavirina/uso terapéutico , Ribonucleósidos/farmacología , Ribonucleósidos/uso terapéutico , Ribosa , Fiebre del Nilo Occidental/diagnóstico , Fiebre del Nilo Occidental/tratamiento farmacológico , Virus del Nilo Occidental/clasificación , Virus del Nilo Occidental/efectos de los fármacos , Virus del Nilo Occidental/genética , Virus del Nilo Occidental/aislamiento & purificaciónRESUMEN
Mosquito-borne infections cause some of the most debilitating human diseases, including yellow fever and malaria, yet we lack an understanding of how disease risk scales with human-driven habitat changes. We present an approach to study variation in mosquito distribution and concomitant viral infections on the landscape level. In a pilot study we analyzed mosquito distribution along a 10-km transect of a West African rainforest area, which included primary forest, secondary forest, plantations, and human settlements. Variation was observed in the abundance of Anopheles, Aedes, Culex, and Uranotaenia mosquitoes between the different habitat types. Screening of trapped mosquitoes from the different habitats led to the isolation of five uncharacterized viruses of the families Bunyaviridae, Coronaviridae, Flaviviridae, and Rhabdoviridae, as well as an unclassified virus. Polymerase chain reaction screening for these five viruses in individual mosquitoes indicated a trend toward infection with specific viruses in specific mosquito genera that differed by habitat. Based on these initial analyses, we believe that further work is indicated to investigate the impact of anthropogenic landscape changes on mosquito distribution and accompanying arbovirus infection.
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Culicidae/virología , Ecosistema , Insectos Vectores/virología , Virus ARN/aislamiento & purificación , África Occidental , Animales , Humanos , Reacción en Cadena de la Polimerasa , Vigilancia de la Población , Virus ARN/genética , Árboles , Clima TropicalRESUMEN
Recently, we identified Batai virus as the M-segment reassortment partner of Ngari virus. Extension of genetic analyses to other orthobunyaviruses related to the Bunyamwera serogroup indicates additional natural genome reassortments. Whereas the relative phylogenetic positions of all three genome segment sequences were similar for Northway and Kairi viruses, the relative positions of Potosi and Main Drain virus M-segment sequences diverged from those of their S- and L-segments. Our findings indicate M-segment reassortment in Potosi and Main Drain viruses and demonstrate natural genome reassortment as a driving force in the evolution of viruses of the Bunyamwera serogroup.
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Virus Bunyamwera/genética , Evolución Molecular , Orthobunyavirus/genética , Virus Reordenados/genética , Recombinación Genética , Secuencia de Aminoácidos , Animales , Virus Bunyamwera/clasificación , Datos de Secuencia Molecular , Orthobunyavirus/clasificación , Filogenia , Análisis de Secuencia de ADNRESUMEN
The choline-containing lipoteichoic acid (LTA, Forssman Antigen) of Streptococcus pneumoniae suppresses the activity of the pneumococcal autolysin, an N-acetyl-muramoyl-L-alanine-amidase (amidase) in aqueous solution [Höltje and Tomasz (1975) Proc. Natl Acad. Sci. USA 72, 1690-1694]. The interaction between LTA and enzyme was used to establish a purification by affinity chromatography on LTA-Sepharose. The amidase could be eluted from the column with choline only. This implies that binding of the enzyme to LTA is mediated via the choline residues of the LTA. Upon binding to the LTA-Sepharose, the amidase converted from the applied E-form (an inactive form of the amidase) to the active C-form, a process which up to now was known to be mediated only by the pneumococcal choline-containing wall teichoic acid. Similar interactions between LTA and amidase seemed to occur in membrane fractions derived from choline-grown cells: the membrane-associated enzyme was present in the C-form and could be detached completely with choline, suggesting that the amidase is bound to the membrane attached LTA rather than being a membrane protein itself. This was supported by the absence of amidase activity in membrane fractions derived from ethanolamine-grown pneumococci, in which choline containing LTA is absent. The LTA-Sepharose-associated amidase was not inhibited, but retained its activity. The enzyme was also not inhibited by lipase-digested LTA. Both are conditions where the LTA is not present in micelles, unlike in aqueous solution. Therefore, mere binding to the LTA is probably not responsible for the inhibitory effect, but inhibition is a manifestation of an inaccessibility of the substrate for the amidase when bound to micellar LTA. When the interactions between choline and amidase were investigated, it was found that high choline concentrations (2%) inhibited the enzyme completely. Even in vivo, 2% choline in the culture medium led to phenotypically amidase-deficient pneumococci. Furthermore, in vitro, low choline concentrations (0.1%) suppressed the wall-mediated conversion. On the other hand, with high choline concentrations (2%) conversion took place in the absence of cell walls. Depending on how the amidase has been converted, the apparent Mr of the resulting C-amidase was different: the cell-wall-converted enzyme was of high Mr, whereas the choline-converted and the LTA-Sepharose-eluted enzyme showed an apparent low molecular mass known for the E-form, when analyzed on sucrose gradients.(ABSTRACT TRUNCATED AT 400 WORDS)
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Amidohidrolasas/antagonistas & inhibidores , Colina/farmacología , Lipopolisacáridos , Ácidos Fosfatidicos/farmacología , Ácidos Teicoicos/farmacología , Sitios de Unión/efectos de los fármacos , Pared Celular/enzimología , Centrifugación por Gradiente de Densidad , Fenómenos Químicos , Química , Cromatografía de Afinidad , Streptococcus pneumoniae/enzimología , Especificidad por Sustrato , SacarosaRESUMEN
Antibodies against the benzylpenicilloyl determinant were used to identify complexes of benzylpenicilloyl and penicillin binding protein (PBP) of several bacterial species on immunoblots. Since radioactive penicillin was not needed, this technique readily allowed in vivo labeling studies even in Escherichia coli, where the saturating concentration was around 0.6 mg/ml. The antibodies showed no substantial cross-reactivity to other beta-lactam-PBP complexes with the exception of 6-aminopenicillanic acid. Surprisingly, some penicilloyl-PBP were hardly recognized by the antiserum, whereas the others could be stained according to the amount of penicillin bound.
Asunto(s)
Anticuerpos , Proteínas Bacterianas , Carboxipeptidasas/análisis , Proteínas Portadoras/análisis , Hexosiltransferasas , Muramoilpentapéptido Carboxipeptidasa/análisis , Penicilina G/inmunología , Peptidil Transferasas , Animales , Bacillus subtilis , Cefalosporinas/metabolismo , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Escherichia coli , Técnicas de Inmunoadsorción , Métodos , Ácido Penicilánico/inmunología , Proteínas de Unión a las Penicilinas , Conejos , Streptococcus pneumoniaeRESUMEN
The nucleotide sequence of a 3,378-bp DNA fragment of Streptococcus pneumoniae that included the structural gene for penicillin-binding protein (PBP) 1a (ponA), which encodes 719 amino acids, was determined. Homologous DNA fragments from an S. oralis strain were amplified with ponA-specific oligonucleotides. The 2,524-bp S. oralis sequence contained the coding region for the first 636 amino acids of a PBP. The coding sequence differed by 437 nucleotides (27%) and one additional triplet, resulting in 87 amino acid substitutions (14%), from S. pneumoniae PBP 1a. Both PBPs are highly homologous to bifunctional high-M(r) Escherichia coli PBPs 1a and 1b.