Api m 6 and Api m 10 as Major Allergens in Patients With Honeybee Venom Allergy.

BACKGROUND: Component-resolved diagnosis plays a key role in the diagnosis and treatment of honeybee venom allergy (HVA). Our aim was to study whether any of the allergens not included in the usual diagnostic platforms are relevant in our population. MATERIAL AND METHODS: The allergenic sensitization profile of Spanish patients who experienced a systemic reaction after a honeybee sting and were diagnosed with HVA was studied by immunoblotting based on raw autochthonous Apis mellifera venom characterized using SDS-PAGE and mass spectrometry and a commercial assay (ImmunoCAP). RESULTS: Allergens in the International Union of Immunological Societies database were detected in the raw A mellifera venom extract used, except Api m 12. Sera from 51 patients with a median (IQR) age of 46.2 years (35.6-54.6) were analyzed. ImmunoCAP revealed Api m 1 and Api m 10 to be major allergens (88.2% and 74.5%, respectively). Moreover, Api m 6 (85.4%) was detected by immunoblotting. CONCLUSION: Api m 1, Api m 6, and Api m 10 are major A mellifera venom allergens in our population.

Api m 6 and Api m 10 as Major Allergens in Patients With Honeybee Venom Allergy

Background: Component-resolved diagnosis plays a key role in the diagnosis and treatment of honeybee venom allergy (HVA). Our aimwas to study whether any of the allergens not included in the usual diagnostic platforms are relevant in our population.Patients and Methods: The allergenic sensitization profile of Spanish patients who experienced a systemic reaction after a honeybee stingand were diagnosed with HVA was studied by immunoblotting based on raw autochthonous Apis mellifera venom characterized usingSDS-PAGE and mass spectrometry and a commercial assay (ImmunoCAP).Results: Allergens in the International Union of Immunological Societies database were detected in the raw A mellifera venom extract used,except Api m 12. Sera from 51 patients with a median (IQR) age of 46.2 years (35.6-54.6) were analyzed. ImmunoCAP revealed Api m 1and Api m 10 to be major allergens (88.2% and 74.5%, respectively). Moreover, Api m 6 (85.4%) was detected by immunoblotting.Conclusion: Api m 1, Api m 6, and Api m 10 are major A mellifera venom allergens in our population (AU)

Antecedentes: El diagnóstico molecular puede ser una herramienta valiosa en el diagnóstico y el tratamiento de la alergia al veneno deabeja. Este estudio investiga si alguno de los alérgenos no incluidos en las plataformas diagnósticas habituales son relevantes en nuestrapoblación.Pacientes y métodos: Estudiamos mediante immunoblotting el perfil de sensibilización alergénica en pacientes españoles diagnosticadosde alergia al veneno de abeja. Los resultados se compararon con los obtenidos usando un ensayo comercial (ImmunoCAP). El venenocrudo de Apis mellifera autóctona se obtuvo y caracterizó mediante SDS-PAGE y espectrometría de masas.Resultados: Los alérgenos descritos en la base de datos International Union of Immunological Societies (IUIS) fueron detectados enel extracto crudo de veneno de A. mellifera utilizado. Se analizaron sueros de 51 pacientes con una edad media de 46,2 años (rangointercuartil 35,6–54,6). Api m 1 y Api m 10 fueron detectados como alérgenos mayoritarios (88,2% y 74,5%, respectivamente) usandoImmunoCAP. Además, se encontró Api m 6 (85,4%) mediante immunoblotting.Conclusión: Nuestra población reconoce Api m 1, Api m 6 y Api m 10 como alérgenos mayoritarios del veneno de A. mellifera (AU)

Thirty years of human infections caused by Yersinia enterocolitica in northern Spain: 1985-2014.

Yersinia enterocolitica infection is a zoonosis with worldwide distribution, gastroenteritis being by far the most common clinical manifestation of human infection. In Gipuzkoa, northern Spain, human Y. enterocolitica infections increased from the mid-1980s to the beginning of the 21st century (from 7·9 to 23·2 annual episodes per 100 000 population) to decrease to 7·2 annual episodes per 100 000 population in the last years of the study. The hospital admission rate due to yersiniosis during the last 15 years of the study was 7·3%. More than 99% of isolates were serotype O:3. Infection affected mainly children under 5 years of age (average rate: 140 episodes per 100 000 population). The incidence in adults was low but hospitalisation increased with age, exceeding 50% in people over 64 years old.

Transcriptional and proteomic stress responses of a soil bacterium Bacillus cereus to nanosized zero-valent iron (nZVI) particles.

Nanosized zero valent iron (nZVI) is emerging as an option for treating contaminated soil and groundwater even though the potentially toxic impact exerted by nZVI on soil microorganisms remains uncertain. In this work, we focus on nanotoxicological studies performed in vitro using commercial nZVI and one common soil bacterium (Bacillus cereus). Results showed a negative impact of nZVI on B. cereus growth capability, consistent with the entrance of cells in an early sporulation stage, observed by TEM. Despite no changes at the transcriptional level are detected in genes of particular relevance in cellular activity (narG, nirS, pykA, gyrA and katB), the proteomic approach used highlights differentially expressed proteins in B. cereus under nZVI exposure. We demonstrate that proteins involved in oxidative stress-response and tricarboxilic acid cycle (TCA) modulation are overexpressed; moreover proteins involved in motility and wall biosynthesis are repressed. Our results enable to detect a molecular-level response as early warning signal, providing new insight into first line defense response of a soil bacterium after nZVI exposure.

Rotavirus genotypes in children in the Basque Country (North of Spain): rapid and intense emergence of the G12[P8] genotype.

Between July 2009 and June 2011, rotavirus was detected in 507 of 4597 episodes of acute gastroenteritis in children aged <3 years in Gipuzkoa (Basque Country, Spain), of which the G-type was determined in 458 (90·3%). During the annual seasonal epidemic of 2010-2011, the unusual G-type 12 was predominant, causing 65% (145/223) of cases of rotavirus gastroenteritis. All the G12 strains were clustered in lineage III and were preferentially associated with P-type 8. This epidemic was characterized by broad geographical distribution (rural and urban) and, over 7 months, affected both infants and children, the most frequently affected being children between 4 and 24 months. Of children with rotavirus G12, 16% required hospital admission, the admission rate in children aged <2 years being 20·7 cases/10 000 children. The sudden emergence and predominance of G12 rotaviruses documented in this winter outbreak suggest that they may soon become a major human rotavirus genotype.

Caracterización farmacológica y análisis funcional de los receptores nicotínicos α 9 α 10 en células romafines aisladas de la médula adrenal de rata / Pharmacological characterization and functional analysis of α 9 α 10 acetylcholine nicotinic receptors in isolated chromaffin cells from the rat adrenal medulla

El descubrimiento de receptores nicotínicos (nAChRs) formadospor las subunidades α9 y α10 en las células de los epitelios sensitivosdel sistema vestibular y auditivo ha motivado su búsqueda enestructuras del sistema nervioso autónomo, como las células cromafinesde la médula adrenal, en las que podrían inducir la hiperpolarizaciónde la membrana celular mediante la activación de canales deK+ dependientes de Ca2+ de baja conductancia iónica (canales SK). Elobjetivo fundamental de nuestro trabajo ha sido determinar la presenciay, en su caso, caracterizar funcionalmente el nAChR α9α10 enlas células cromafines de la médula adrenal de la rata. Con ese propósito,hemos empleado cultivos primarios de células cromafines obtenidasde la glándula adrenal de rata y recurrido a la técnica electrofisiológicade patch-clamp para registrar las corrientes iónicasgeneradas por la activación de los nAChRs del conjunto de la membranacelular. Asimismo, hemos empleado la α-conotoxina RgIA, unpéptido capaz de bloquear de forma selectiva los nAChRs formadospor las subunidades α9 y α10. Los resultados obtenidos aportan evidenciasfarmacológicas que permiten concluir que las células cromafinesde la rata expresan nAChRs α9α10 funcionales que, además, desempeñarían un papel modulador comportamiento eléctrico de dichascélulas(AU)

The identification of acetylcholine nicotinic receptors (nAChRs)formed by α9 and α10 subunits in the sensory cells of the vestibularand auditory systems, prompted us to investigate their presence inadrenomedullary chromaffin cells, in which they could mediate membranehyperpolarization through the activation of small-conductanceCa2+-dependent K+ channels (SK channels). The aim of the currentstudy has been to pharmacologically identify α9α10 nAChRs and initiatetheir functional characterization in isolated chromaffin cellsfrom the rat adrenal medulla. We have employed the patch clamptechnique to record either the ionic currents generated by the activationof nAChRs or the associated changes in membrane potential. Wetook advantage of the specificity of α-conotoxin RgIA for the nAChRsformed by α9 and α10 subunits. Our pharmacological results suggestthat the rat chromaffin cells express functional α9α10 nAChRs thatwould influence the electrical behaviour of these cells(AU)

Rotavirus y crisis convulsivas. Una asociación poco frecuente aunque bien definida / Rotavirus and seizures. A well-defined uncommon association

Introducción: La infección por rotavirus, además de los síntomas digestivos, puede producir múltiples complicaciones neurológicas. Entre estas se encuentran las convulsiones afebriles asociadas a gastroenteritis leve (CBG). A pesar de tener unas características bien definidas, su incidencia es poco conocida. Métodos: Se seleccionaron los diagnósticos de diarrea aguda de los niños que fueron hospitalizados en el Hospital Donostia, entre julio-1996 y junio-2008 y con edades entre un mes y 5 años. Se seleccionaron aquellos casos con diagnóstico asociado de convulsión. Resultados: Se detectó rotavirus en 419 de los 1.114 niños hospitalizados por GEA (39,2%). Cinco (1,2%) presentaron un cuadro compatible con CBG. Los episodios sucedieron entre diciembre y enero en todos los casos. La edad media de presentación fue 19,6 meses. El número de crisis por paciente fue de 2,6 de media (rango 1–4). Todas las crisis fueron cortas, siendo la de mayor duración de 15min. La duración total del cuadro fue de 1,6 días de media, con un máximo de 3 días. Las pruebas complementarias realizadas en todos los casos, fueron normales. En el seguimiento posterior, uno de los niños a los 26 meses presentó de nuevo un cuadro compatible con esta entidad. Ninguno ha vuelto a presentar crisis y todos tienen un desarrollo psicomotor normal. Conclusiones: La entidad CBG, es una entidad poco frecuente dentro de las gastroenteritis agudas asociadas a rotavirus, pero tiene unas características clínicas muy precisas que permiten su identificación, pudiendo evitar excesivas pruebas complementarias y tratamientos médicos agresivos (AU)

Introduction: Rotavirus infection, besides gastrointestinal symptoms, may cause several neurological complications. Among these, are benign convulsions with mild gastroenteritis (CwG). Despite having well defined clinical features, its incidence is not well known. Methods: We selected discharge diagnoses of acute diarrhea in children aged 1 month to 5 years who were admitted to Donostia Hospital between July 1996 and June 2008. Among them, we selected those cases with concomitant diagnosis of seizure. Results: Rotavirus was detected in 419 of 1114 children hospitalized for gastroenteritis. (39.2%), Five (1.2%) had symptoms compatible with CwG. The episodes occurred between December and January in all cases. The mean age at diagnosis was 19.6 months. The number of seizures per patient was 2.6 (range 1–4). All the crises were short, the longest being 15min. The total duration of the episode was 1.6 days on average, with up to 3 days. Additional tests performed in all cases, were normal. In subsequent follow-up, one child at 26 months had another episode compatible with this entity at 26 months. During the follow-up period, all patients displayed normal psychomotor development with noe recurrence of seizures. Conclusion: CwG is a rare entity within all acute gastroenteritis associated with rotavirus, but has very specific clinical features that enable it to be identified which could avoid excessive medical tests, and aggressive treatment (AU)

[Rotavirus and seizures. A well-defined uncommon association]. / Rotavirus y crisis convulsivas. Una asociación poco frecuente aunque bien definida.

INTRODUCTION: Rotavirus infection, besides gastrointestinal symptoms, may cause several neurological complications. Among these, are benign convulsions with mild gastroenteritis (CwG). Despite having well defined clinical features, its incidence is not well known. METHODS: We selected discharge diagnoses of acute diarrhea in children aged 1 month to 5 years who were admitted to Donostia Hospital between July 1996 and June 2008. Among them, we selected those cases with concomitant diagnosis of seizure. RESULTS: Rotavirus was detected in 419 of 1114 children hospitalized for gastroenteritis. (39.2%), Five (1.2%) had symptoms compatible with CwG. The episodes occurred between December and January in all cases. The mean age at diagnosis was 19.6 months. The number of seizures per patient was 2.6 (range 1-4). All the crises were short, the longest being 15min. The total duration of the episode was 1.6 days on average, with up to 3 days. Additional tests performed in all cases, were normal. In subsequent follow-up, one child at 26 months had another episode compatible with this entity at 26 months. During the follow-up period, all patients displayed normal psychomotor development with noe recurrence of seizures. CONCLUSION: CwG is a rare entity within all acute gastroenteritis associated with rotavirus, but has very specific clinical features that enable it to be identified which could avoid excessive medical tests, and aggressive treatment.

Rotavirus genotypes in children in the Basque Country (northern Spain) over a 13-year period (July 1996-June 2009).

To describe the circulation dynamics of human rotavirus genotypes in a region of southern Europe over a 13-year period. The G- and P-types of rotavirus isolates of patients aged less than 5 years were analyzed using multiplex, reverse transcription polymerase-chain reaction. Of 1,538 isolates investigated, a combination of individual G- and P-types was obtained in 1,368. The most prevalent combination was G1[P8] (57.5% of the genotyped strains), which circulated in all seasons and predominated in nine out of 13 seasons. The strains G2[P4] (14.4%), G3[P8] (8.3%), G4[P8] (5.5%) and G9[P8] (13.4%) circulated intermittently. G4[P8] strains were frequently detected in the 1990s but only sporadically after 2000. G9[P8] strains emerged from 1997-1998 and became dominant in the winters of 2005-2007. G2[P4] strains were predominant in 2003-2004, before the rotavirus vaccines were commercialized. Unusual combinations of common G- and P-types and the presence of unusual G- and/or P-types (G6[P14], G8[P8], G8[P14] and G12[P8]) were rarely observed (<1%). We found no differences in hospitalization due to distinct genotypes. G-types G1-G4 and G9 represented >99% of circulating rotaviruses over a 13-year period. Therefore, vaccine efficacy in this region can be expected to be high.

Incidence of hospitalization due to community-acquired rotavirus infection: a 12-year study (1996-2008).

The incidence of hospitalization for acute gastroenteritis (AGE) is a useful parameter to assess the utility of the new rotavirus vaccines in high-income countries. Children hospitalized for AGE were identified by searching hospital discharge data and the records of the microbiology laboratory of Hospital Donostia. Rotavirus antigen was investigated in 96.1% of the 1114 children aged 1 month to <5 years hospitalized for AGE in the study period. Nearly 40% were rotavirus positive (44.9% of the 798 children aged 1 month to <2 years), with G1[P8] being the predominant genotype. The mean annual incidence rate of hospitalization due to rotavirus AGE was 29.8 and 63.7 cases/10 000 inhabitants in the <5 and <2 years age groups, respectively, in 1996-1999, decreasing to 13.6 and 27.4 cases/10 000 inhabitants in <5 and <2 years age groups, respectively, in 2002-2005 (P<0.001). This decrease coincided with a significant increase in the consumption of oral rehydration solutions.

Proteomic analysis by two-dimensional differential gel electrophoresis (2D DIGE) of a high-pressure effect in Bacillus cereus.

High hydrostatic pressure (HHP) is a new method used to reduce or eliminate microorganisms that are present in food. Proteins are known to be the most important target of high pressure in living organisms. The main goal of this investigation was focused on the changes that occur on the proteins of Bacillus cereus under HHP stress conditions. The two-dimensional differential gel electrophoresis (2D DIGE) technique allows for a simultaneous resolution of thousands of proteins based on fluorescent prelabeling of the samples with spectrally resolvable fluorescent CyDyes. The results of proteomics profiling show an average of 1300 spots being detected. The analysis revealed 75 spot proteins whose abundance is modified after the application of high pressure, of which 66 were decreased after the HHP treatment. Among them, flagellin was the protein that changed the most. The differential expression of some proteins after HHP treatment at 700 MPa may suggest a reduction of virulence and protective response against oxidative stress in flagellated Bacillus .

Analgesia epidural y resultados obstétricos / Epidural analgesia and obstetric outcomes

Se realizó un estudio retrospectivo, descriptivo y comparativo acerca de los efectos de la analgesia epidural frente a no analgesia epidural en el parto, en una muestra de 1.928 partos acontecidos en un período de 3 años y se atendió a una serie de parámetros que se pueden ver influenciados de manera positiva o negativa, como son factores relacionados con las distintas fases del parto, distocias, instrumentación, índice de cesáreas, repercusiones neonatales e impacto sobre el suelo pélvico. Tras el tratamiento estadístico, se observaron diferencias significativas en la prolongación del parto, el mayor número de instrumentación, el aumento en la tasa de cesáreas y el incremento del índice de episiotomías en multíparas en los partos conducidos bajo analgesia epidural. Por el contrario, no se dieron diferencias significativas en las distocias en occipito posterior, fiebre intraparto, partos con cesárea anterior o episiotomías en primíparas. Hubo significación estadística a favor de los partos sin analgesia epidural en el número de infecciones neonatales, así como desgarros perineales de primer grado en multíparas e integridad perineal en multíparas. A tenor de estos resultados obtenidos en nuestro hospital, nos planteamos incorporar al documento de consentimiento informado sobre analgesia epidural todos los posibles efectos adversos derivados de ésta (AU)

We performed a descriptive retrospective study comparing the effects of the application versus non application of epidural analgesia during delivery in1928 women over a 3-year period. Several parameters that could be positively or negatively influenced by epidural analgesia administration, such as factors related to the different stages of delivery, dystocia, instrumentation, rate of cesarean sections, neonatal repercussion and impact on the pelvic floor, were evaluated. Statistical analysis revealed that epidural analgesia was associated with prolongation of delivery and increases in the number of instruments involved and the rates of cesarean section and episiotomy in multiparas. These differences were statistically significant. In contrast, no significant differences were found in the occurrence of dystocia in the occipito posterior position, intrapartum fever, deliveries with prior cesarian section or episiotomy in primiparas. Statistically significant differences were found in favor of deliveries without epidural analgesia in the number of neonatal infections, as well as in first degree lacerations and perineal integrity in multiparous women In view of the results obtained in our hospital, we are considering adding all the possible adverse effects associated with epidural analgesia to our informed consent document (AU)

Correlación de la analgesia epidural en el aumento de la tasa de cesáreas / Association between epidural analgesia and increased cesarian section rate

Presentamos un estudio cuyo objetivo es definir la incidencia de la analgesia epidural (AE) sobre el índice de cesáreas. Para ello analizamos de manera retrospectiva 1.928 partos y comparamos 2 grupos: los conducidos bajo AE, frente a los partos sin epidural. Introducimos como sesgos las siguientes variables: paridad, cesárea programada, cesárea anterior y cesárea programada más cesárea previa. Al aplicar el análisis estadístico obtenemos diferencias significativas al suprimir el sesgo de cesárea programada, tanto en primíparas (p = 0,02) como en multíparas (p = 0,049); la tasa de cesáreas se incrementa en los partos con epidural (AU)

The aim of this study was to determine the effect of epidural analgesia on the cesarian section rate. To do this, we retrospectively analyzed 1928 deliveries and compared those performed under epidural analgesia with those performed without epidural analgesia. The following variables were considered as possible sources of bias: parity, elective cesarean section, previous caesarean section, and elective cesarean section plus previous caesarean section. When applying the statistical analysis, we obtained significant differences when suppressing the bias of elective cesarean section, both in primiparas (p = 0.02) and in multiparas (p = 0.049); the rate of cesarean section was increased in deliveries performed with epidural analgesia (AU)

Salmonella enteric infections in Gipuzkoa, Spain, 1983-2000.

The incidence of Salmonella enteric infections in Gipuzkoa, Spain, was estimated by studying a stable population between 1983 and 2000. Only stool culture confirmed cases were included. The annual mean rate of infection in children under 2 years old was 1121 per 100,000 (CI 95%; 1060-1181). This age group had the highest relative risk (RR), 16.2-fold higher than the RR of those aged over 14 years. Salmonella Enteritidis was the most prevalent serovar (80.4% of all patients), followed by Salmonella Typhimurium (11.7%).

Purple membrane-polyacrilamide films as holographic recording materials.

The holographic parameters of purple membrane-polyacrylamide films obtained from a mutant form of Halobacterium salinarum (originally Halobacterium halobium) were measured. The synthesized films have an absorption of around 2.5 at 532 nm and a pH of 8.65. The results show that diffraction efficiencies of about 1.2 % (measured at 633 nm) can be achieved with writing intensities in the range of 200-400 mW/cm2 (532 nm), and these values remain constant after saturation. Pump-probe experiments were also used to measure the M state lifetime and our PM films were found to have the lowest M state lifetime described at this pH.

CMY-2-producing Salmonella enterica, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis and Escherichia coli strains isolated in Spain (October 1999-December 2000).

CMY-2 plasmid-mediated AmpC beta-lactamase (CMY-2) was detected in 21 isolates from two hospitals located in different geographical regions of Spain between October 1999 and December 2000. The isolates comprised two Salmonella enterica serovars (Mikawasima and Montevideo), 16 Escherichia coli, one Klebsiella pneumoniae, one Klebsiella oxytoca and one Proteus mirabilis. In addition to the expected resistance to beta-lactams, including extended-spectrum cephalosporins and cefoxitin, all isolates showed a broad spectrum of associated resistance. All were resistant to sulfamethoxazole, chloramphenicol, tetracycline and streptomycin, and all but two were also resistant to gentamicin. Five isolates were studied in detail and all transferred CMY-2 and other resistance determinants by conjugation. Genomic DNA restriction pattern analysis of the E. coli isolates excluded the dissemination of a single clone. To the best of our knowledge this is the first time that CMY-2 has been detected in P. mirabilis, K. oxytoca and S. enterica serovars Mikawasima and Montevideo. It is also the first time that CMY-2 has been described in Spain.

CL100/MKP-1 modulates JNK activation and apoptosis in response to cisplatin.

Treatment of cells with cisplatin induces a sustained activation of the stress activated protein kinase SAPK/JNK and the mitogen-activated protein kinase p38. Activation of JNK by cisplatin is necessary for the induction of apoptosis. Expression of the MAPK phosphatases CL100/MKP-1 and hVH-5 selectively prevents JNK/SAPK activation by cisplatin in a dose dependent fashion and results in protection against cisplatin-induced apoptosis. In contrast, expression of the ERK-specific phosphatase Pyst1 inhibits JNK/SAPK activity only when expressed at very high levels and does not confer protection against cisplatin. Furthermore, expression of a catalytically inactive mutant of CL100 in 293 cells decreases the IC50 for cisplatin and increases the toxicity of transplatin. This effect seems to be mediated by an increase in JNK activity since p38 activity is unaffected. These results suggest that dual-specificity MAPK phosphatases may be candidate drug targets in order to optimize cisplatin based therapeutic protocols.

Incidence, seasonality and serotypes of rotavirus in Gipuzkoa (Basque Country), Spain. A 14-year study.

Over a 14-year period (1984-97) the presence of rotavirus in stool samples from children under 15 years with acute gastroenteritis was studied by enzymoimmunoanalysis. Serotyping (G1-G4) was performed using monoclonal antibodies. A total of 17,348 children under 15 were investigated. Rotavirus was detected in 3637 (21.0%) specimens, 74.6% of which were from children younger than 2 years old. G1 and G4 were the most frequent serotypes. In 1991-7, the minimum incidence of rotavirus gastroenteritis in children under 4 years of age was 21.7 cases/1000 children/year. By the age of 5 years, at least 1 out of 11.3 children and probably 1 out of every 5-6 children in this area had experienced an episode of rotavirus gastroenteritis that required medical care. In the 1984-90 period a clear seasonality was not observed but in the second period of the study (1991-7), seasonality was marked, with peak activity in winter.

In-vitro, in-vivo and ex-vivo studies with oral beta-lactams against Streptococcus pneumoniae.

In-vitro killing curves, a protection model in immunocompetent mice and an ex-vivo model in volunteers were used to evaluate the efficacy of amoxycillin, cefuroxime axetil and cefpodoxime proxetil against a penicillin-intermediate-resistant Streptococcus pneumoniae (MIC = 1 mg/L) (PRP) and a penicillin-susceptible S. pneumoniae (MIC = 0.01 mg/L) (PSP). In vitro, the maximal bactericidal activity was obtained with amoxycillin (1 x MIC versus 2 x MIC cefpodoxime and 4 x MIC cefuroxime). Mice were challenged by intraperitoneal inoculation and treated orally every 8 h for 48 h with 2.5, 5, 7.5 and 10 mg/kg doses of these three beta-lactams. The rate of survival for the PSP strain was 100% with any dose of the three tested antibiotics. For the PRP strain only amoxycillin showed 100% survival with 5, 7.5 or 10 mg/kg doses. Twelve healthy volunteers were randomized in three groups and each received two doses of the oral antibiotic. Blood samples were collected from each subject 0.5 h and 2 h after drug administration and serum inhibitory and bactericidal titres were measured. Similar values were obtained with the three beta-lactams against PSP but against PRP only the serum of volunteers that had taken amoxycillin exhibited serum bactericidal titres of > or = 8. This study suggests a more predictable therapeutic efficacy against pneumococcal infection with amoxycillin than with available oral cephalosporins.