A Metagenomic Analysis Provides a Culture-Independent Pathogen Detection for Atopic Dermatitis

PURPOSE: Atopic dermatitis (AD) is an inflammatory skin disease, significantly affecting the quality of life. Using AD as a model system, we tested a successive identification of AD-associated microbes, followed by a culture-independent serum detection of the identified microbe. METHODS: A total of 43 genomic DNA preparations from washing fluid of the cubital fossa of 6 healthy controls, skin lesions of 27 AD patients, 10 of which later received treatment (post-treatment), were subjected to high-throughput pyrosequencing on a Roche 454 GS-FLX platform. RESULTS: Microbial diversity was decreased in AD, and was restored following treatment. AD was characterized by the domination of Staphylococcus, Pseudomonas, and Streptococcus, whereas Alcaligenaceae (f), Sediminibacterium, and Lactococcus were characteristic of healthy skin. An enzyme-linked immunosorbent assay (ELISA) showed that serum could be used as a source for the detection of Staphylococcus aureus extracellular vesicles (EVs). S. aureus EV-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) were quantified in the serum. CONCLUSIONS: A metagenomic analysis together with a serum detection of pathogen-specific EVs provides a model for successive identification and diagnosis of pathogens of AD.

Caracterización de pacientes pediátricos con aislamiento de Oligella en la Fundación Hospital de la Misericordia, en Bogotá, Colombia, 2010-2014 / Characterization of pediatric patients with isolation of Oligella in Fundación Hospital de la Misericordia, in Bogotá, Colombia, 2010-2014

Las infecciones por Oligella son muy raras. No existen cifras en la literatura con respecto a su prevalencia en población general. El objetivo de este documento es presentar las características de pacientes pediátricos en quienes se realizó aislamiento de los miembros del género Oligella . Se obtuvieron 8 cultivos positivos, dichos aislamientos provienen de muestras sanguíneas y de esputo, con mayor prevalencia en hombres en el 75% de los casos, con edades entre uno y 11 años, principalmente con enfermedad hematooncológica. Tres aislamientos fueron considerados contaminación y no tuvieron significado clínico; uno recibió tratamiento con trimetropim sulfametoxazol con adecuada respuesta clínica, los demás recibieron manejo antibiótico con meropenem. Solo un paciente falleció, por la severidad de su enfermedad de base. A pesar de su baja prevalencia, la infección por Oligella genera cuadros de respuesta inflamatoria importantes en pacientes con inmunosupresión que, de acuerdo con nuestra experiencia, responden al uso de carbapenémicos.

Oligella infections are rare. The prevalence in the general population is unknown. The objective of this paper is to present the characteristics of pediatric patients in whom isolation of members of the genus Oligella was performed. Eight positive cultures were obtained; 7 were from blood samples and one was from sputum. A high percentage of the patients were males (75%), aged between one and 11 years, most with hemato-oncological disease. Three isolates were considered contaminated and did not have clinical significance; one patient received trimethoprim-sulfamethoxazole treatment with an adequate clinical response and 4 received antibiotic treatment with meropenem. Only one of the patients died, due to the severity of his primary disease. Despite its low prevalence, Oligella infection generates high levels of inflammation in patients with immunosuppression. According to our experience, a good therapeutic response is obtained by using carbapenems.

Evaluation of Microbial Load in Oropharyngeal Mucosa from Tannery Workers

BACKGROUND: Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees. METHODS: The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated. RESULTS: The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid. CONCLUSION: Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers.

Characterization of oral bacterial diversity of irradiated patients by high-throughput sequencing / 国际口腔科学杂志·英文版

The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy. Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients. Eight patients with head and neck cancers were involved in this study. For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy. A total of 147,232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis, representing 3,460 species level operational taxonomic units (OTUs) and 140 genus level taxa. Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics. Moreover, the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves. This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.