Bacteriophage applications for fresh produce food safety.

Foodborne illnesses, mainly bacteria, are a major cause of morbidity and mortality worldwide. Pathogenic bacteria are involved in almost every step within the fresh produce chain compromising the companies' food safety programs and generating an ascending number of foodborne outbreaks in various regions of the world. Recently, bacteriophages return to the status of biocontrol agents. These bacteria-killing viruses are able to reduce or eliminate pathogenic bacterial load from raw and ready to eat foods. Phages are efficient, strain specific, easy to isolate and manipulate, and for that reasons, they have been used in pre and post harvest processes alone or mixed with antimicrobial agents for biocontrolling pathogenic bacteria. In this review, we focused on the feasibility of using lytic bacteriophage on fresh fruits and vegetables industry, considering challenges and perspectives mainly at industrial production level (packinghouses, supermarkets), where high volume of phage preparations and consequently high costs may be required.

¿La crisis económica condiciona la aparición de un nuevo perfil de riesgo en viajeros internacionales? / Has the economic crisis led to a new risk profile for international travelers?

Introducción. La crisis económica mundial condiciona la migración de trabajadores europeos hacia países en vías de desarrollo con alta incidencia de enfermedades infecciosas. El objetivo de este estudio es valorar si este contexto produce un aumento de los riesgos de los viajeros internacionales que se desplazan por motivos laborales (VML). Métodos. Estudio observacional retrospectivo. La población de estudio fueron los VML atendidos antes de su viaje en una Unidad de Salud Internacional durante los años 2007 (año anterior al inicio de la crisis europea) y 2012 (con la crisis estructural establecida). Se realizó un análisis comparativo sociodemográfico y de los factores de riesgo presentes entre ambos grupos. Resultados. En 2007 y 2012 se atendieron un total de 9.197 viajeros. Los VML fueron 344 (3,4%); en 2007, 101 (2,8%) y en 2012, 243 (4,5%) (p<0,001). La edad media de los viajeros fue de 38,1 (DE: 10,57) años. El destino más frecuente fue África subsahariana con 164 (47,6%) casos. Se prescribió quimioprofilaxis antipalúdica a 152 (44%) y presentaban comorbilidades 80 (23,25%). Los VML del 2012 presentaron significativamente mayor edad (p=0,05), más comorbilidades (p=0,018), y mayor proporción de estancias en zonas rurales (p=0,009) durante periodos más largos (p=0,001). Conclusiones. A 5 años del inicio de la crisis económica, existe una variación en el perfil del VML. Su número ha aumentado significativamente, así como la proporción de los que presentan factores de riesgo para contraer enfermedades importadas. Las Unidades de Salud Internacional deberían adaptarse a las nuevas circunstancias y adoptar medidas preventivas en dicho colectivo (AU)

Introduction. The economic world crisis has led to the migration of European workers to developing countries with a high incidence of infectious diseases. The objective of this study was to assess whether this context has produced an increase in the risks to international travelers for work reasons (TWR). Methods. Observational, retrospective study. The study population included TWR who were attended before traveling at an International Health Unit in the year 2007 (the year before the initiation of the European crisis) and in the year 2012 (when the structural crisis was established). A comparative socioeconomic analysis was performed as well as an analysis of the risk factors present in both groups. Results. In 2007 and 2012 a total of 9197 travelers were attended. Of these, there were 344 TWR (3.4%); 101 TWR (2.8%) in 2007 and 243 TWR (4.5%) in 2012 (p<.001). The average age of the travelers was 38.1 years (SD: 10.57). The most common destination was Sub-Saharan Africa, in 164 (47.6%) of the cases. Malaria chemoprophylaxis was prescribed to 152 travelers (44%) and 80 presented comorbidity (23.25%). The TWR from 2012 presented a significantly greater age (p=.05), more comorbidity (p=.018) and a greater proportion of stays in rural areas (p=.0009) for longer time periods (p=.001). Conclusions. At 5 years from the start of the economic crisis, there was a change in the profile of TWR. Their number has increased significantly, as has the proportion who present risk factors for contracting imported diseases. The International Health Units should adapt to these new circumstances and adopt preventive measures for this population (AU)

Has the economic crisis led to a new risk profile for international travellers? / ¿La crisis económica condiciona la aparición de un nuevo perfil de riesgo en viajeros internacionales?

INTRODUCTION: The economic world crisis has led to the migration of European workers to developing countries with a high incidence of infectious diseases. The objective of this study was to assess whether this context has produced an increase in the risks to international travellers for work reasons (TWR). METHODS: Observational, retrospective study. The study population included TWR who were attended before travelling at an International Health Unit in the year 2007 (the year before the initiation of the European crisis) and in the year 2012 (when the structural crisis was established). A comparative socioeconomic analysis was performed as well as an analysis of the risk factors present in both groups. RESULTS: In 2007 and 2012 a total of 9,197 travellers were attended. Of these, there were 344 TWR (3.4%); 101 TWR (2.8%) in 2007 and 243 TWR (4.5%) in 2012 (p<0.001). The average age of the travellers was 38.1 years (SD: 10.57). The most common destination was Sub-Saharan Africa, in 164 (47.6%) of the cases. Malaria chemoprophylaxis was prescribed to 152 travellers (44%) and 80 presented comorbidity (23.25%). The TWR from 2012 presented a significantly greater age (p=0.05), more comorbidity (p=0.018) and a greater proportion of stays in rural areas (p=0.0009) for longer time periods (p=0.001). CONCLUSIONS: At 5 years from the start of the economic crisis, there was a change in the profile of TWR. Their number has increased significantly, as has the proportion who present risk factors for contracting imported diseases. The International Health Units should adapt to these new circumstances and adopt preventive measures for this population.

Evolution of the antimicrobial resistance of Pseudomonas aeruginosa in Spain: second national study (2003).

The second national prevalence study of Pseudomonas aeruginosa has been carried out in Spain. A total of 1250 clinical isolates of P. aeruginosa were collected from 127 hospitals in 1 week in 2003 and the resistance data gathered from the isolates was compared with those of the first study in 1998 (1014 isolates from 136 hospitals). Antimicrobial susceptibility testing was performed in both studies in the same laboratory. The most active antimicrobials were piperacillin, piperacillin-tazobactam, and amikacin (< or =10% resistant) and resistance to these antimicrobials did not change over the time. The least active were ofloxacin and gentamicin (> or =30% resistant). From 1998 to 2003, resistance increased significantly to ciprofloxacin (23% vs. 28%, respectively, p=0.015); ofloxacin (30% vs. 37%, p=0.002); imipenem (14% vs. 18%, p=0.017) and meropenem (8% vs. 13%, p <0.001). Resistance to aztreonam (23%), ceftazidime (16%), cefepime (20%), ticarcillin (13%) and tobramycin (11%) remained stable. Isolates from inpatients were significantly more resistant than those from outpatients to all antimicrobials, with the exception of fluoroquinolones and aminoglycosides (p <0.01). Isolates from outpatients were significantly more resistant to these two groups (p <0.05) than to other antimicrobials. In Spain, from 1998 to 2003, the susceptibility pattern of P. aeruginosa to antimicrobial agents has changed. Isolates have become significantly more resistant to fluoroquinolones and carbapenems. However, resistance to beta-lactams and aminoglycosides remains stable.

Evolution of the antimicrobial resistance of Pseudomonas aeruginosa in Spain: Second National Study (2003

Se ha realizado el segundo estudio nacional de prevalencia de Pseudomonas aeruginosa en España. Durante una semana en el año 2003 se recuperaron 1250 aislamientos cl¨ªnicos de esta bacteria en 127 hospitales españoles y los datos de resistencia se compararon con los obtenidos en el primer estudio realizado en 1998 (1014 aislamientos de 136 hospitales). Las pruebas de sensibilidad se realizaron en el mismo laboratorio en ambos estudios. Los antimicrobianos que se mostraron m¨¢s activos fueron piperacilina, piperacilina-tazobactam y amikacina (30% resistencia). Desde el año 1998 al 2003 se observ¨® un aumento de resistencias significativo en ciprofloxacino (23% vs. 28%, respectivamente, p=0.015), ofloxacino (30% vs. 37%, p=0.002), imipenem (14% vs. 18%, p=0.017) y meropenem (8% vs. 13%, p<0.001). Los porcentajes de resistencia a aztreonam (23%), ceftazidima (16%), cefepima (20%), ticarcillina (13%) y tobramicina (11%) permanecieron estables. Los aislamientos de pacientes ingresados fueron significativamente m¨¢s resistentes que los de los pacientes ambulatorios para todos los antimicrobianos ensayados excepto para las fluoroquinolonas y los aminoglucosidos (p<0.01). Los aislamientos procedentes de la comunidad fueron m¨¢s resistentes significativamente en esos dos grupos (p <0.05) que en el resto de los antimicrobianos. En España, los patrones de sensibilidad de P. aeruginosa a los antimicrobianos ha cambiado desde 1998 a 2003. Los aislamientos son m¨¢s resistentes a las fluorquinolonas y los carbapenemes, y se mantienen estables los porcentajes de resistencia para betalact¨¢micos y aminogluc¨®sidos

The second national prevalence study of Pseudomonas aeruginosa has been carried out in Spain. A total of 1250 clinical isolates of P. aeruginosa were collected from 127 hospitals in 1 week in 2003 and the resistance data gathered from the isolates was compared with those of the first study in 1998 (1014 isolates from 136 hospitals). Antimicrobial susceptibility testing was performed in both studies in the same laboratory. The most active antimicrobials were piperacillin, piperacillin-tazobactam, and amikacin (¡Ü10% resistant) and resistance to these antimicrobials did not change over the time. The least active were ofloxacin and gentamicin (¡Ý30% resistant). From 1998 to 2003, resistance increased significantly to ciprofloxacin (23% vs. 28%, respectively, p=0.015); ofloxacin (30% vs. 37%, p=0.002); imipenem (14% vs. 18%, p=0.017) and meropenem (8% vs. 13%, p <0.001). Resistance to aztreonam (23%), ceftazidime (16%), cefepime (20%), ticarcillin (13%) and tobramycin (11%) remained stable. Isolates from inpatients were significantly more resistant than those from outpatients to all antimicrobials, with the exception of fluoroquinolones and aminoglycosides (p <0.01). Isolates from outpatients were significantly more resistant to these two groups (p <0.05) than to other antimicrobials. In Spain, from 1998 to 2003, the susceptibility pattern of P. aeruginosa to antimicrobial agents has changed. Isolates have become significantly more resistant to fluoroquinolones and carbapenems. However, resistance to beta-lactams and aminoglycosides remains stable

Streptococcus pneumoniae skin and soft tissue infections: characterization of causative strains and clinical illness.

Streptococcus pneumoniae is an uncommon cause of skin and soft tissue infections, yet the incidence and clinical significance of its isolation in samples of skin or soft tissues in unselected hospital samples is poorly understood. In the present study, a review was conducted of the records of all patients with skin and soft tissue infections due to S. pneumoniae at a university hospital between January 1994 and December 2005. The isolates were identified by standard methods and were serotyped, and susceptibility testing was performed by the broth microdilution method following the guidelines of the Clinical and Laboratory Standards Institute. During the study period, 3,201 isolates of S. pneumoniae were recovered from several sources. Of these, 69 (2.2%) were from skin and soft tissue samples (69 patients). Complete information could not be obtained for 13 patients. Of the 56 patients remaining, 36 (64.3%) were infected and fulfilled the inclusion criteria. The following types of infections were observed: surgical wound infection (n = 11), burn infection (n = 7), pyomyositis (n = 6), cellulitis (n = 4), perineal or scrotal abscess (n = 3), and other (n = 5). Thirty-one (86%) patients had a favorable outcome, and 5 (13.8%) patients died. Mortality was directly attributable to S. pneumoniae infection in three of the five fatal cases. Of the 39 S. pneumoniae isolates obtained (36 from skin and soft tissues, three from blood cultures), 58.9% were penicillin nonsusceptible, 7.7% were cefotaxime nonsusceptible, and 20.5% were erythromycin resistant. The most frequent serotypes were 3, 19, 11, and 23. Of the overall number of isolates of S. pneumoniae recovered in a general institution, 2.2% involved skin and soft tissues (of which 64% were clinically significant). Mortality due to pneumococcal skin and soft tissue infections was low.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Spain: a multicentre prevalence study (2002).

A point-prevalence study, performed in 2002 in 143 Spanish hospitals, collected 439 isolates of Staphylococcus aureus. Of these, 134 (30.5%) were resistant to methicillin (i.e., MRSA). Susceptibility testing was performed by a microdilution method, and mecA was detected by PCR. The isolates were characterised by phage typing, pulsed-field gel electrophoresis (PFGE) after SmaI digestion, and SCCmec typing. The 134 MRSA isolates showed resistance to ciprofloxacin (93.3%), tobramycin (88.8%), erythromycin (67.9%), clindamycin (59.7%), gentamicin (42.5%), mupirocin (17.9%), rifampicin (5.2%) and trimethoprim-sulphamethoxazole (5.2%). All of the isolates were susceptible to glycopeptides. Twenty-five resistance patterns were found, of which four accounted for 66% of the isolates. Phage group III was the most frequent (41.1%). PFGE revealed 31 different patterns, with ten major clones (including two predominant clones with variable antibiotypes that accounted for 43.3% of the MRSA isolates) and 21 sporadic patterns. Two isolates belonged to two variants of the Iberian clone (ST247-MRSA-I), one to the Brazilian clone (ST239-MRSA-III), and seven to the EMRSA-16 clone (ST36-MRSA-II). SCCmecIV accounted for 70.2% of the isolates (73.9% were type IVA), while SCCmecI, SCCmecII and SCCmecIII accounted for 22.1%, 6.9% and 0.8% of isolates, respectively, with three non-typeable isolates. Isolates of SCCmecIV and SCCmecIVA were predominantly nosocomial (95.8% and 97.1%, respectively). None of the isolates produced Panton-Valentine leukocidin. Thus, two clones carrying SCCmecIV and SCCmecIVA, respectively, were predominant among nosocomial MRSA isolates throughout Spain.

Fluconazole resistance mechanisms in Candida krusei: the contribution of efflux-pumps.

The main resistance mechanism for fluconazole in Candida krusei is the diminished sensitivity of the target enzyme cytochrome P450 sterol 14 alpha-demethylase (CYP51) to inhibition by azole agents. An alternative mechanism of resistance, efflux-pump activity, has been proposed. The aim of our study was to find out the possible contribution of efflux-pumps in conferring resistance to fluconazole in 33 C. krusei isolates from different clinical sources. The activity of efflux-pumps was checked using the inhibitor CCCP (carbonyl cyanide 3-chloro-phenylhydrazone), which decreases the minimum inhibitory concentration (MIC) when resistance is attributed. We established a concentration of 0.5 microg/ml of CCCP. The susceptibility patterns of our isolates for five antifungal drugs (amphotericin B, fluconazole, itraconazole, flucytosine and voriconazole) were determined according to an NCCLS M27-A2 protocol modification (Sensititre Yeast One). We tested all the strains before and after adding CCCP to the RPMI medium. The MIC90s and ranges of the drugs were identical before and after addition of CCCP. The MIC for fluconazole was higher than for the other antifungals. The new triazoles were active and the MICs were lower, although this should be interpreted carefully as the drugs showed different cut-offs. Only one isolate showed a two-fold decrease in MIC to fluconazole when CCCP was added. We did not find any multi-resistant strains. According to our study with C. krusei, CCCP-inhibited efflux-pumps do not play a significant role in resistance to fluconazole.

Demolition of a hospital building by controlled explosion: the impact on filamentous fungal load in internal and external air.

The demolition of a maternity building at our institution provided us with the opportunity to study the load of filamentous fungi in the air. External (nearby streets) and internal (within the hospital buildings) air was sampled with an automatic volumetric machine (MAS-100 Air Samplair) at least daily during the week before the demolition, at 10, 30, 60, 90,120, 180, 240, 420, 540 and 660 min post-demolition, daily during the week after the demolition and weekly during weeks 2, 3 and 4 after demolition. Samples were duplicated to analyse reproducibility. Three hundred and forty samples were obtained: 115 external air, 69 'non-protected' internal air and 156 protected internal air [high efficiency particulate air (HEPA) filtered air under positive pressure]. A significant increase in the colony count of filamentous fungi occurred after the demolition. Median colony counts of external air on demolition day were significantly higher than from internal air (70.2 cfu/m(3) vs 35.8 cfu/m(3)) (P < 0.001). Mechanical demolition on day +4 also produced a significant difference between external and internal air (74.5 cfu/m(3) vs 41.7 cfu/m(3)). The counts returned to baseline levels on day +11. Most areas with a protected air supply yielded no colonies before demolition day and remained negative on demolition day. The reproducibility of the count method was good (intra-assay variance: 2.4 cfu/m(3)). No episodes of invasive filamentous mycosis were detected during the three months following the demolition. Demolition work was associated with a significant increase in the fungal colony counts of hospital external and non-protected internal air. Effective protective measures may be taken to avoid the emergence of clinical infections.

In vitro activity of linezolid against Clostridium difficile.

We examined the in vitro activity of linezolid against Clostridium difficile, including isolates with reduced susceptibility to metronidazole or vancomycin. The MIC at which 50% of the isolates were inhibited (MIC50) and MIC90 were 0.5 and 2 microg/ml, respectively (range, 0.03 to 4 microg/ml). MICs were always

Comparative in vitro activity of the new quinolone gemifloxacin (SB-265805) with other fluoroquinolones against respiratory tract pathogens.

The in vitro activity of gemifloxacin (SB-265805) was compared with that of other fluoroquinolones against 302 clinical isolates of Streptococcus pneumoniae, 300 clinical isolates of Haemophilus influenzae and 28 clinical isolates of Moraxella catarrhalis, including multiply resistant strains. Gemifloxacin at 0.12 mg/L inhibited all microorganisms tested. MIC(90) values of gemifloxacin, trovafloxacin, grepafloxacin and levofloxacin against all (630) isolates tested were 0.03, 0.12, 0.12 and 1 mg/L, respectively. MIC(90) values of the same fluoroquinolones against S. pneumoniae were 0.06, 0.25, 0.12 and 1 mg/L, respectively.

Unidades de salud internacional centradas en atención primaria

La globalización económica, la aplicación de las nuevas tecnologías a los transportes y comunicación de información, bienes y personas junto con la incorporación de España a un marco de referencia europeo han conllevado un aumento muy considerable en el número de viajeros a destinos con condiciones sanitarias muy diferentes a las nuestras, así como a una llegada de abundante mano de obra inmigrada en un país sin tradición en salud internacional. El inevitable desarrollo de ésta a corto o medio plazo deberá contar con la atención primaria si quiere abordar el fenómeno de manera planificada y como estrategia para aumentar la eficiencia de unas actividades (consejo al viajero, vacunación internacional) que recaen de lleno en lo que son las funciones básicas de la atención primaria. El despliegue de unidades de salud internacional plenamente funcionantes sólo es posible dotando a la atención primaria, y estableciendo desde ella circuitos de apoyo por una parte a los profesionales de primera línea asistencial y por otra a los ámbitos hospitalarios y especializados de cada zona (AU)

[Incidence and etiology of viremia in 2,619 patients]. / Incidencia y etiología de la viremia en 2.619 pacientes.

BACKGROUND: Virus investigation, specially cytomegalovirus (CMV), in blood has increased such that the capacity of hospitalary laboratories is threatened with collapse. The causal agents of viremia are analyzed being correlated with the clinical symptoms and underlying disease to establish the selection criteria of patients for virologic study. METHODS: Two thousand six hundred nineteen patients suspected of having viral infection, fundamentally by CMV were studied over 6 years by 4,394 blood samples. Of these patients 1,646 were immunosuppressed, 824 were considered immunocompetent and this data was unknown in 149 patients. The leukocytes were separated using standardized techniques being seeded in cell cultures (human embryo lung fibroblasts). RESULTS: Three hundred forty-seven specimens corresponding to 242 patients were positive with isolation of the following pathogens: 327 strains of CMV, 4 enterovirus, 2 adenovirus, 1 herpes simplex virus, 1 varicella-zoster, another 5 unidentified cytopathic agents, 6 strains of toxoplasma and 1 Cryptococcus. With regard to the base disease, 302 positive samples to CMV pertained to 204 immunosuppressed patients: 103 (13.6% positives among the cases studied) AIDS or AIDS-related complex, 54 (21.3%) kidney transplant patients, 31 (24.8%) liver transplant patients, 2 (1.5%) lung transplant patients, and 2 (1.5%) bone marrow transplant patients. A non CMV microorganism was isolated in 13 samples from 12 immunosuppressed patients. Only 24 (2.5% of those studied) immunocompetent or with unknown immunity status had viremia by CMV, being detected in 25 samples. Non CMV cytopathic agents were isolated in another 7 samples from 6 patients. CONCLUSIONS: Analysis of blood cultures allows the isolation of cytomegalovirus and occasionally other unsuspected agents such as toxoplasma. This investigation is indicated in immunosuppressed patients but not in immunocompetent patients who present a febrile syndrome with no clinical suspicion of cytomegalovirus infection.