Phenotypic and molecular characterization of Staphylococcus aureus isolates conducted in nares of psoriatic patients attending a public hospital in Argentina / Caracterización fenotípica y molecular de aislamientos de Staphylococcus aureus portados en narinas de pacientes con psoriasis que concurren a un hospital público en Argentina

Abstract Although Staphylococcus aureus increases its relative abundance in psoriasis when compared with the microbiome of healthy subjects, it is not the most important microorganism underlying this disease. However, there is scant data on the role and molecular features of S. aureus strains in psoriasis; therefore, the aim of this study was to evaluate nasal carriage of this microorganism, its phenotypic and molecular characteristics as well as the impact of host factors on its carriage in psoriatic patients. The presence of S. aureus was analyzed in nasal swabs from 46 healthy volunteers and 50 psoriatic patients by conventional microbiology techniques. Nasal carriage of S. aureus was higher in psoriatic patients than in the control group (37.24% vs 22.98%, respectively), being associated to sex (male), age (adults) and severity of the disease (more frequent in moderate and severe cases). Determination of antibiotic resistance detected 12% of (-lactam resistant isolates, with variable accompanying resistance to macrolides, aminoglycosides and fluoroquinolones. No resistance to rifampicin, vancomycin, mupirocin or trimethoprim/sulfamethoxazole was found. A preliminary molecular characterization of the isolates was performed by PCR amplification of virulence genes. Molecular characterization of the strains did not reveal a predominant strain in psoriatic patients. Although we established host factors related to increased carriage of S. aureus in psoriatic patients, we could not establish the predominance of one type of strain. Genomic and transcriptomic analysis of the isolated strains would be necessary to address this point.

Resumen A pesar de que Staphylococcus aureus incrementa su abundancia relativa en la psoriasis cuando se compara con el microbioma de personas sanas, no es el microorganismo más importante subyacente a la enfermedad. Sin embargo, existen pocos datos sobre el papel y las características moleculares de las cepas de S. aureus en pacientes con psoriasis. Nuestro objetivo fue evaluar la portación nasal de este microorganismo, sus características fenotípicas y moleculares, y el impacto de factores del hospedador sobre dicha portación en estos pacientes. Se analizó la presencia de S. aureus en hisopados nasales de 46 voluntarios sanos y 50 pacientes con psoriasis mediante técnicas microbiológicas convencionales. Se encontró mayor portación en pacientes con psoriasis que en el grupo control (37,24% vs. 22,98%, respectivamente) y esta estuvo asociada al sexo (masculino), la edad (adultos) y la gravedad de la enfermedad (más frecuente en casos moderados a graves). El 12% de los aislamientos de S. aureus mostraron resistencia a betalactámicos, con resistencia acompañante a macrólidos, aminoglucósidos y fluoroquinolonas en grado variable. No se encontró resistencia a rifampicina, vancomicina, mupirocina o trimetroprima/sulfametoxazol. Se realizó una caracterización molecular preliminar de los aislamientos por amplificación de genes de virulencia mediante PCR. Si bien se identificaron factores relacionados con el hospedador que incrementan la portación nasal de S. aureus en pacientes con psoriasis, la caracterización molecular de las cepas no reveló ninguna característica genotípica predominante asociada a esta afección. Se necesitan más estudios genómicos y transcriptómicos para profundizar en esta caracterización.

Phenotypic and molecular characterization of Staphylococcus aureus isolates conducted in nares of psoriatic patients attending a public hospital in Argentina.

Although Staphylococcus aureus increases its relative abundance in psoriasis when compared with the microbiome of healthy subjects, it is not the most important microorganism underlying this disease. However, there is scant data on the role and molecular features of S. aureus strains in psoriasis; therefore, the aim of this study was to evaluate nasal carriage of this microorganism, its phenotypic and molecular characteristics as well as the impact of host factors on its carriage in psoriatic patients. The presence of S. aureus was analyzed in nasal swabs from 46 healthy volunteers and 50 psoriatic patients by conventional microbiology techniques. Nasal carriage of S. aureus was higher in psoriatic patients than in the control group (37.24% vs 22.98%, respectively), being associated to sex (male), age (adults) and severity of the disease (more frequent in moderate and severe cases). Determination of antibiotic resistance detected 12% of ß-lactam resistant isolates, with variable accompanying resistance to macrolides, aminoglycosides and fluoroquinolones. No resistance to rifampicin, vancomycin, mupirocin or trimethoprim/sulfamethoxazole was found. A preliminary molecular characterization of the isolates was performed by PCR amplification of virulence genes. Molecular characterization of the strains did not reveal a predominant strain in psoriatic patients. Although we established host factors related to increased carriage of S. aureus in psoriatic patients, we could not establish the predominance of one type of strain. Genomic and transcriptomic analysis of the isolated strains would be necessary to address this point.

Bioinformatic Analysis of a Set of 14 Temperate Bacteriophages Isolated from Staphylococcus aureus Strains Highlights Their Massive Genetic Diversity.

Epidemiology and virulence studies of Staphylococcus aureus showed that temperate bacteriophages are one of the most powerful drivers for its evolution not only because of their abundance but also because of the richness of their genetic payload. Here, we report the isolation, genome sequencing, and bioinformatic analysis of 14 bacteriophages induced from lysogenic S. aureus strains from human or veterinary (cattle) origin. The bacteriophages belonged to the Siphoviridae family; were of similar genome size (40 to 45 kbp); and fell into clusters B2, B3, B5, and B7 according to a recent clustering proposal. One of the phages, namely, vB_SauS_308, was the most unusual one, belonging to the sparsely populated subcluster B7 but showing differences in protein family contents compared with the rest of the members. This phage contains a type I endolysin (one catalytic domain and noncanonical cell wall domain [CBD]) and a host recognition module lacking receptor binding protein, cell wall hydrolase, and tail fiber proteins. This phage also lacked virulence genes, which is opposite to what has been reported for subcluster B6 and B7 members. None of six phages, taken as representatives of each of the four subclusters, showed activity on coagulase-negative staphylococci (excepted for two Staphylococcus hominis strains in which propagation and a very slow adsorption rate were observed) nor transducing ability. Immunity tests on S. aureus RN4220 lysogens with each of these phages showed no cross immunity. IMPORTANCE To the best of our knowledge, this set of sequenced bacteriophages is the largest one in South America. Our report describes for the first time the utilization of MultiTwin software to analyze the relationship between phage protein families. Notwithstanding the fact that most of the genetic information obtained correlated with recently published information, due to their geographical origin, the reported analysis adds up to and confirms currently available knowledge of Staphylococcus aureus temperate bacteriophages in terms of phylogeny and role in host evolution.

Evaluation of factors influencing expression and extraction of recombinant bacteriophage endolysins in Escherichia coli.

BACKGROUND: Endolysins are peptidoglycan hydrolases with promising use as environment-friendly antibacterials mainly when used topically. However, in general, endolysin expression is hampered by its low solubility. Thus, a critical point in endolysin industrial production is optimizing their expression, including improvement of solubility and recovery from cell extracts. RESULTS: We report the expression of two endolysins encoded in the genome of phages infecting Staphylococcus aureus. Expression was optimized through changes in the concentration of the inducer and growth temperature during the expression. Usually, only 30-40% of the total endolysin was recovered in the soluble fraction. Co-expression of molecular chaperones (DnaK, GroEL) or N-term fusion tags endowed with increased solubility (DsbC, Trx, Sumo) failed to improve that yield substantially. Inclusion of osmolytes (NaCl, CaCl2, mannitol, glycine betaine, glycerol and trehalose) or tensioactives (Triton X-100, Tween 20, Nonidet P-40, CHAPS, N-lauroylsarcosine) in the cell disruption system (in the absence of any molecular chaperone) gave meager improvements excepted by N-lauroylsarcosine which increased recovery to 54% of the total endolysin content. CONCLUSION: This is the first attempt to systematically analyze methods for increasing yields of recombinant endolysins. We herein show that neither solubility tags nor molecular chaperones co-expression are effective to that end, while induction temperature, (His)6-tag location and lysis buffer additives (e.g. N-lauroylsarcosine), are sensible strategies to obtain higher levels of soluble S. aureus endolysins.

Correction: Broad-range lytic bacteriophages that kill Staphylococcus aureus local field strains.

[This corrects the article DOI: 10.1371/journal.pone.0181671.].

Risk factors associated with tuberculosis mortality in adults in six provinces of Argentina.

Tuberculosis (TB) remains a cause of illness and death across the world, especially in developing countries and vulnerable population groups. In 2013, 1.5 million died from the disease worldwide. In Argentina, the largest proportion of TB-related deaths occurred in the northern provinces. Several international studies reported that TB mortality was related to the presence of certain comorbidities and socio-demographic characteristics. Our aim was to investigate the main risk factors associated with TB mortality in adults from six provinces in Argentina, especially those with higher TB mortality rates. A retrospective case-control study was conducted. It included all patients of =18 years with clinical and/or bacteriological TB diagnosis who underwent treatment from January 1st, 2012 to June 30th, 2013. Socio-demographic, clinical and bacteriological variables were surveyed. Information on 157 cases and 281 controls was obtained. Patients reported as deceased to the TB Control Program were considered cases, and those whose treatment result was reported as successful in the same time period were considered controls. For 111 deaths, the average time elapsed between the start of treatment and death was 2.3 months; median: 1. TB-related mortality was associated with poor TB treatment adherence (OR: 3.7 [1.9-7.3], p: 0.000), AIDS (OR: 5.29 [2.6-10.7], p: 0.000), male gender (OR: 1.7 [1.1-2.5], p: 0.009), belonging to indigenous people (OR: 7.2 [2.8-18.9], p:0. 000) and age = 50 (OR: 2.2 [1.4-3.3], p: 0.000). By multivariate analysis the two first associations were confirmed. This study sets up the basis for planning inter-program and inter-sector work to accelerate the decline in the inequitable TB mortality.

Risk factors associated with tuberculosis mortality in adults in six provinces of Argentina

Tuberculosis (TB) remains a cause of illness and death across the world, especially in developing countries and vulnerable population groups. In 2013, 1.5 million died from the disease worldwide. In Argentina, the largest proportion of TB-related deaths occurred in the northern provinces. Several international studies reported that TB mortality was related to the presence of certain comorbidities and socio-demographic characteristics. Our aim was to investigate the main risk factors associated with TB mortality in adults from six provinces in Argentina, especially those with higher TB mortality rates. A retrospective case-control study was conducted. It included all patients of =18 years with clinical and/or bacteriological TB diagnosis who underwent treatment from January 1st, 2012 to June 30th, 2013. Socio-demographic, clinical and bacteriological variables were surveyed. Information on 157 cases and 281 controls was obtained. Patients reported as deceased to the TB Control Program were considered cases, and those whose treatment result was reported as successful in the same time period were considered controls. For 111 deaths, the average time elapsed between the start of treatment and death was 2.3 months; median: 1. TB-related mortality was associated with poor TB treatment adherence (OR: 3.7 [1.9-7.3], p: 0.000), AIDS (OR: 5.29 [2.6-10.7], p: 0.000), male gender (OR: 1.7 [1.1-2.5], p: 0.009), belonging to indigenous people (OR: 7.2 [2.8-18.9], p:0. 000) and age = 50 (OR: 2.2 [1.4-3.3], p: 0.000). By multivariate analysis the two first associations were confirmed. This study sets up the basis for planning inter-program and inter-sector work to accelerate the decline in the inequitable TB mortality.

En 2013, 1.5 millones de personas murieron por tuberculosis (TB) en el mundo, especialmente en países en desarrollo y grupos de población vulnerables. En Argentina, la mayor proporción de muertes asociadas con TB ocurrió en las provincias del norte. Estudios internacionales observaron que la mortalidad por TB estaba relacionada con comorbilidades y características sociodemográficas. Este estudio pretendió investigar cuáles eran los principales factores de riesgo asociados con la mortalidad por TB en adultos de seis provincias argentinas, especialmente aquellas con mayores tasas de mortalidad por TB. Se realizó un estudio retrospectivo casos-controles, incluyendo todos los pacientes = 18 años con diagnóstico clínico y/o bacteriológico de TB en tratamiento entre el 1° de enero de 2012 y el 30 de junio de 2013. Se obtuvo información de 157 casos y 281 controles, considerándose casos los pacientes notificados como fallecidos al Programa de TB y controles aquellos cuyo resultado de tratamiento fue notificado como éxito o curado en el mismo período de tiempo. El tiempo transcurrido entre el comienzo del tratamiento y la muerte fue 2.3 meses; mediana: 1. Las muertes relacionadas con TB estuvieron asociadas con: escasa adherencia al tratamiento (OR: 3.7 [1.9-7.3], p: 0.000), sida (OR: 5.29 [2.6-10.7], p: 0.000), género masculino (OR: 1.7 [1.1-2.5], p: 0.009), pertenencia a pueblos originarios (OR: 7.2 [2.8-18.9], p: 0.000) y edad = 50 (OR: 2.2 [1.4-3.3], p: 0.000). Por análisis multivariado, se confirmaron las dos primeras asociaciones. Este estudio sienta las bases para planificar acciones destinadas a acelerar el descenso de la mortalidad por TB.

Broad-range lytic bacteriophages that kill Staphylococcus aureus local field strains.

Staphylococcus aureus is a very successful opportunistic pathogen capable of causing a variety of diseases ranging from mild skin infections to life-threatening sepsis, meningitis and pneumonia. Its ability to display numerous virulence mechanisms matches its skill to display resistance to several antibiotics, including ß-lactams, underscoring the fact that new anti-S. aureus drugs are urgently required. In this scenario, the utilization of lytic bacteriophages that kill bacteria in a genus -or even species- specific way, has become an attractive field of study. In this report, we describe the isolation, characterization and sequencing of phages capable of killing S. aureus including methicillin resistant (MRSA) and multi-drug resistant S. aureus local strains from environmental, animal and human origin. Genome sequencing and bio-informatics analysis showed the absence of genes encoding virulence factors, toxins or antibiotic resistance determinants. Of note, there was a high similarity between our set of phages to others described in the literature such as phage K. Considering that reported phages were obtained in different continents, it seems plausible that there is a commonality of genetic features that are needed for optimum, broad host range anti-staphylococcal activity of these related phages. Importantly, the high activity and broad host range of one of our phages underscores its promising value to control the presence of S. aureus in fomites, industry and hospital environments and eventually on animal and human skin. The development of a cocktail of the reported lytic phages active against S. aureus-currently under way- is thus, a sensible strategy against this pathogen.

Staphylococcus aureus nasal carriage in health care workers: First report from a major public hospital in Argentina / Portación nasal de Staphylococcus aureus en trabajadores de la salud: primer reporte en un hospital público en Argentina

Staphylococcus aureus causes numerous mild to severe infections in humans, both in health facilities and in the community. Patients and health care workers (HCWs) may disseminate strains during regular medical examinations or hospitalization. The aim of this study was to determine the nasal carriage rate of methicillin-susceptible and methicillin-resistant S. aureus among health care workers at Hospital Provincial del Centenario, a public general hospital in Rosario, Argentina. A transversal study was conducted on 320 health care workers. Nasal swabs were taken and presumptive S. aureus colonies were isolated. Bacterial identity and methicillin resistance status were confirmed by amplification of the nuc and mec genes. Chi square test and Fisher exact test were used for statistical analysis. Of 320 HCWs, 96 (30%) were nasal carriers of S. aureus, 20 of whom (6.3%) carried methicillin-resistant S. aureus (MRSA) and 76 (23.7%) methicillin-susceptible S. aureus (MSSA). Carriage was within thepublished values for physicians (30%) and higher for technicians (57%). Accompanying resistance (62/96, 64.6%) was detected, including resistance to fluoroquinolones (23/96, 24%), aminoglucosides (13/96, 13.5%) or to macrolides (33/96, 34.4%). All the strains were susceptible to vancomycin whereas only 3.1% (3/96), all of them on MSSA strains, were resistant to mupirocin. This study is the first one of its kind in Argentina and one of the few performed in South America, to highlight the relevance of nasal carriage of MRSA and MSSA in health care personnel and brings to light the need for consensus recommendations for regular S. aureus carriage screening as well as for decolonization strategies.

Staphylococcus aureus es agente causal de numerosas infecciones en humanos, que pueden ser desde leves hasta graves, y circula tanto en la comunidad como en las instalaciones de los centros de salud. Los pacientes y los trabajadores de la salud pueden diseminar cepas durante los exámenes médicos de rutina o durante la hospitalización. El foco de este estudio fue determinar la tasa de portación nasal de S. aureus sensible o resistente a meticilina en trabajadores de la salud del Hospital Provincial del Centenario, un hospital público de atención primaria en Argentina. Se llevó a cabo un estudio transversal en 320 trabajadores de la salud (TS). Se tomaron hisopados nasales y se aislaron colonias presuntivas de S. aureus. La identidad de las bacterias y su resistencia a meticilina fueron confirmadas por amplificación de los genes nuc y mec. El análisis estadístico comprendió el test de la chi al cuadrado y el test de exactitud de Fisher. De 320 TS, 96 (30%) fueron portadores nasales de S. aureus, de los cuales 20 (6,3% del total) llevaban cepas de S. aureus resistentes a meticilina (SARM) y 76 (23,7% del total) eran portadores de cepas sensibles a meticilina (SASM). La portación entre los médicos fue del 30% y estuvo dentro de los niveles publicados; dentro del subgrupo del personal técnico la portación fue superior: 57%. Se detectaron resistencias acompañantes (64,6%; 62/96) a fluoroquinolonas (24%; 23/96), aminoglucósidos (13,5%; 13/96) o macrólidos (34,4%; 33/96). Todas las cepas fueron sensibles a vancomicina y solo el 3,1% (3/96), las 3 SASM, fueron resistentes a mupirocina. Este estudio, el primero en su tipo en Argentina y uno de los pocos hechos en América del Sur, remarca la relevancia de la portación nasal de SARM y SASM en el personal de atención de la salud y evidencia la necesidad de contar con recomendaciones consensuadas para el tamizaje regular de S. aureus, así como de estrategias de descolonización.

Staphylococcus aureus nasal carriage in health care workers: First report from a major public hospital in Argentina.

Staphylococcus aureus causes numerous mild to severe infections in humans, both in health facilities and in the community. Patients and health care workers (HCWs) may disseminate strains during regular medical examinations or hospitalization. The aim of this study was to determine the nasal carriage rate of methicillin-susceptible and methicillin-resistant S. aureus among health care workers at Hospital Provincial del Centenario, a public general hospital in Rosario, Argentina. A transversal study was conducted on 320 health care workers. Nasal swabs were taken and presumptive S. aureus colonies were isolated. Bacterial identity and methicillin resistance status were confirmed by amplification of the nuc and mec genes. Chi square test and Fisher exact test were used for statistical analysis. Of 320 HCWs, 96 (30%) were nasal carriers of S. aureus, 20 of whom (6.3%) carried methicillin-resistant S. aureus (MRSA) and 76 (23.7%) methicillin-susceptible S. aureus (MSSA). Carriage was within thepublished values for physicians (30%) and higher for technicians (57%). Accompanying resistance (62/96, 64.6%) was detected, including resistance to fluoroquinolones (23/96, 24%), aminoglucosides (13/96, 13.5%) or to macrolides (33/96, 34.4%). All the strains were susceptible to vancomycin whereas only 3.1% (3/96), all of them on MSSA strains, were resistant to mupirocin. This study is the first one of its kind in Argentina and one of the few performed in South America, to highlight the relevance of nasal carriage of MRSA and MSSA in health care personnel and brings to light the need for consensus recommendations for regular S. aureus carriage screening as well as for decolonization strategies.

Eritrodisestesia o síndrome mano pie. Presentación de dos casos y revisión de la literatura / Erythrodysesthesia or foot hand syndrome Presentation of two cases and review of the literature

La eritrodisestesia, o síndrome mano pie, es una reacción adversa relacionada con algunos agentes quimioterápicos. Se caracteriza por comenzar con un pródromo de disestesia palmo-plantar y, entre 2 a 4 días, la sensación progresa a un dolor quemante con edema y eritema en placas bien delimitadas y simétricas. Los quimioterápicos que se asocian con más frecuencia son la doxorrubicina, 5-fluorouracilo, capecitabina, citarabina y docetaxel. Es más frecuente y severo en mujeres, pacientes de edad avanzada o con compromiso vascular periférico. Se presentan dos pacientes de sexo femenino. La primera con cáncer de ovario en tratamiento con doxorrubicina liposomal que presentó eritrodisestesia luego del quinto ciclo de quimioterapia. La segunda paciente con diagnóstico de cáncer de mama que recibió tratamiento con capecitabina presentando síntomas luego del segundo ciclo de quimioterapia. El interés de la presentación es la consulta a dermatología por un síndrome que constituye un efecto adverso que potencialmente limita el uso de determinados antineoplásicos. Sin embargo, educando al paciente, con intervenciones farmacológicas y ajuste de dosis, es posible aliviar los síntomas continuando una terapéutica efectiva (AU)

Erythrodysesthesia, or hand foot syndrome, is a side effect related to some chemotherapeutic agents. It is characterized by a prodrome of palmoplantar dysesthesia followed by burning pain with edema and erythema on well-defined and symmetrical plaques, 2-4 days later. Doxorubicin, 5-fluorouracil, capecitabine, cytarabine and docetaxel are the most frequently associated chemotherapy drugs. Women, elderly or peripheral vascular compromise patients are more frequent and severe affected. Two female patients are reported. The first patient with ovarian cancer in treatement with liposomal doxorrubicin developed erythrodysesthesia after the fifth cycle of chemotherapy. Meanwhile the second patient diagnosed with breast cancer in treatment with capecitabine developed it after the second cycle of chemotherapy. The interest of this report is the dermatological consultation about a side effect syndrome which potentially limits the prescription of certain antineoplastic drugs. However, patients can continue specific treatment by indicating dose adjustment and prescribing medicine to relieve the symptoms (AU)