Molecular Characterization of Staphylococcus aureus Strains Isolated from Mobile Phones.

The widespread use of mobile phones (MP) among healthcare personnel might be considered as an important source of contamination. One of the most pathogenic bacteria to humans is Staphylococcus aureus, which can be transmitted through the constant use of MP. Nevertheless, which specific type of strains are transmitted and which are their sources have not been sufficiently studied. The aim of this study is to determine the source of contamination of MP and characterize the corresponding genotypic and phenotypic properties of the strains found. Nose, pharynx, and MP samples were taken from a group of health science students. We were able to determinate the clonality of the isolated strains by pulsed-field gel electrophoresis (PFGE) and spa gene typing (spa-type). Adhesin and toxin genes were detected, and the capacity of biofilm formation was determined. Several of the MP exhibited strains of S. aureus present in the nose and/or pharynx of their owners. methicillin-susceptible Staphylococcus aureus (MSSA), hospital-acquired methicillin-resistant S. aureus (HA-MRSA), and community-acquired methicillin-resistant S. aureus (CA-MRSA) strains were found, which indicated a variety of genotypes. This study concludes that MP can be contaminated with the strains of S. aureus present in the nose and/or pharynx of the owners; these strains can be of different types and there is no dominant genotype.

Cytotoxic Activity of Cu/TiO2 Nanoparticles on Uterine-Cervical Cancer Cells.

Nanoparticles based on metal oxides serve as carrier matrices for molecules of biological interest. In this work, we used different copper complexes that were coupled to TiO2 nanoparticles. Nanoparticles were prepared with the sol-gel method. The Cu/TiO2 nanoparticles were characterized through ultraviolet-visible and Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, nitrogen physisorption analysis, and scanning electron microscopy. Their biological activity was determined through DNA degradation and their cytotoxic effect on HeLa cells. The Cu/TiO2 nanoparticles presented a pore size between 2 and 6 nm, the size of nanoparticles agglomerates was between 100 and 500 nm. The nanoparticles of Cu/TiO2 degraded DNA starting at 15 min. The half maximal inhibitory concentration in HeLa cells depends on the used cooper complexes, the kinetics of cell death is of first order. Results revealed that these nanoparticles could be applied in uterine-cervical cancer treatment.

Frecuencia y caracterización de Staphylococcus spp. en la mucosa bucal de pacientes diabéticos y no diabéticos / Frequency and characterization of Staphylococcus spp. in the buccal mucosa of diabetic and non-di

Antecedentes: Dentro de la gran diversidad de microorganismos en la microbiota oral, el género Staphylococcus es causante de una gran variedad de infecciones, desde leves hasta diseminadas que pueden causar la muerte. Los portadores de estas bacterias tienen más riesgo de presentar infecciones por estas mismas. Un grupo vulnerable de sufrir infecciones por estos microorganismos son los pacientes diabéticos por sus características sistémicas propias de la enfermedad, deterioro inmunológico y locales bucales, por lo que es importante conocer si son portadoras de este grupo de bacterias. Objetivo: Determinar la frecuencia de colonización por Staphylococcus spp. en aislamientos obtenidos de la mucosa bucal de pacientes diabéticos y sin diabetes. Material y métodos: Se tomó un raspado superficial de la mucosa bucal de personas diabéticas y sin diabetes para cultivo y análisis microbiológico. Se sembró en agar sal manitol y los aislados se identificaron por galerías API Staph. La concentración de glucosa se determinó con equipo Accu-Chek. El análisis fue descriptivo, las diferencias y asociaciones se investigaron con χ2 y T Student. Se consideró estadísticamente significativo cuando el valor de p < 0.05. Resultados: La colonización por Staphylococcus spp. total fue de 73.7%, no hubo diferencia significativa entre diabéticos y no diabéticos (p = 0.946). S. epidermidis se identificó en 69% y S. aureus en 17.6%, sin diferencia entre ambos grupos con p = 0.556 y p = 0.428 respectivamente. Setenta y seis por ciento de los pacientes portadores de prótesis bucales estaban colonizados con Staphylococcus spp. Conclusiones: No se encontró que los pacientes diabéticos tuvieran porcentajes significativamente mayores de colonización por Staphylococcus spp. a pesar de sus condiciones particulares inmunológicas, glucemia anormal y disminución de flujo salival en la cavidad bucal (AU)

Background: Within the great diversity of microorganisms in the buccal microbiota, the genus Staphylococcus is the cause of a great variety of infections ranging from mild to disseminated, which can cause death. The carriers of these bacteria are more at risk of developing infections by themselves. A vulnerable group to suffer infections by these microorganisms are diabetic patients due to their systemic characteristics of the disease, immunological deterioration and local buccal, so it is important to know if they are carriers of this group of bacteria. Objective: The objective was determined the frequency of colonization by Staphylococcus spp. in isolates obtained from the oral mucosa of diabetic and without diabetes patients. Material and methods: A superficial scraping of the buccal mucosa of diabetic and without diabetes people was taken for culture and microbiological analysis. It was seeded in sal manitol agar and the isolates were identified by API Staph galleries. The glucose concentration was determined with Accu-Chek equipment. The analysis was descriptive, differences and associations were investigated with χ2 and Student T. It was considered statistically significant when the value of p < 0.05. Results: Total colonization by Staphylococcus spp. was 73.7%, there was no significant difference between diabetics and nondiabetics (p = 0.946). S. epidermidis was identified in 69% and S. aureus in 17.6%, without difference between both groups with p = 0.556 and p = 0.428 respectively. 76% of patients with oral prostheses were colonized with Staphylococcus spp. Conclusions: Diabetic patients were not found to have significantly higher rates of colonization by Staphylococcus spp. despite their particular immunological conditions, abnormal glycemia and decreased salivary flow in the oral cavity (AU)

Community-acquired methicillin-resistant Staphylococcus aureus can persist in the throat.

Colonization by Staphylococcus aureus is an important factor in infections caused by this microorganism. Among the colonization niches of staphylococci are the nose, skin, intestinal tract, and, recently, the throat has been given relevance. Infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) can be fatal. Persistence of S. aureus is an important process in the pathogenesis of this microorganism and must be studied. The aim of this study was to determine the persistence of S. aureus in the throat, and characterized the strains. We studied the persistence of S. aureus for 6 years in the throat of apparently healthy people. The isolated strains from the persistent carriers were characterized through PFGE, spa-typing, SCCmec typing, resistance to methicillin, presence of virulence genes (adhesins and toxins), and the formation of biofilm. We found persistent and intermittent carriers of S. aureus in the throat, with methicillin-sensitive (MSSA), methicillin-resistant (MRSA) strains, and confirmed for the first time that CA-MRSA colonizes this niche. These strains can colonize persistently the throat for four years or more. Typification of strains through PFGE and spa-typing revealed that some carriers present the same strain, whereas others present different strains along the period of persistence. Almost all strains induced a strong biofilm formation. All strains presented adhesin and toxin genes, but no shared genotype was found. We conclude that S. aureus, including CA-MRSA strains, can remain persistently in the throat, finding a wide variability among the persistent strains.