Possible overestimation of surface disinfection efficiency by assessment methods based on liquid sampling procedures as demonstrated by in situ quantification of spore viability.

The standard test methods used to assess the efficiency of a disinfectant applied to surfaces are often based on counting the microbial survivors sampled in a liquid, but total cell removal from surfaces is seldom achieved. One might therefore wonder whether evaluations of microbial survivors in liquid-sampled cells are representative of the levels of survivors in whole populations. The present study was thus designed to determine the "damaged/undamaged" status induced by a peracetic acid disinfection for Bacillus atrophaeus spores deposited on glass coupons directly on this substrate and to compare it to the status of spores collected in liquid by a sampling procedure. The method utilized to assess the viability of both surface-associated and liquid-sampled spores included fluorescence labeling with a combination of Syto 61 and Chemchrome V6 dyes and quantifications by analyzing the images acquired by confocal laser scanning microscopy. The principal result of the study was that the viability of spores sampled in the liquid was found to be poorer than that of surface-associated spores. For example, after 2 min of peracetic acid disinfection, less than 17% ± 5% of viable cells were detected among liquid-sampled cells compared to 79% ± 5% or 47% ± 4%, respectively, when the viability was evaluated on the surface after or without the sampling procedure. Moreover, assessments of the survivors collected in the liquid phase, evaluated using the microscopic method and standard plate counts, were well correlated. Evaluations based on the determination of survivors among the liquid-sampled cells can thus overestimate the efficiency of surface disinfection procedures.

The resistance of Bacillus atrophaeus spores to the bactericidal activity of peracetic acid is influenced by both the nature of the solid substrates and the mode of contamination.

AIMS: To evaluate the impact of the mode of contamination in relation with the nature of solid substrates on the resistance of spores of Bacillus atrophaeus -selected as surrogates of Bacillus anthracis- to a disinfectant, peracetic acid. METHODS AND RESULTS: Six materials confronted in urban and military environments were selected for their different structural and physicochemical properties. In parallel, two modes of contamination were examined, i.e. deposition and immersion. Deposition was used to simulate contamination by an aerosol and immersion by an extended contact with liquids. A pronounced difference in the biocontamination levels and spatial organization of spores was observed depending on the mode of contamination and the nature of the solid substrate considered, with consequences on decontamination. Contamination by immersion led to lower efficiency of peracetic acid decontamination than contamination by deposition. Infiltration of spores into porous materials after immersion is one reason. In contrast, the deposition mode aggregates cells at the surface of materials, explaining the similar disinfecting behaviour of porous and nonporous substrates when considering this inoculation route. CONCLUSIONS: The inoculation route was shown to be as influential a parameter as material characteristics (porosity and wettability) for decontamination efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: These results provide comparative information for the decontamination of B. atrophaeus spores in function of the mode of contamination and the nature of solid substrates.

Improving diabetic retinopathy screening through a statewide telemedicine program at a large federally qualified health center.

BACKGROUND: Diabetic retinopathy (DR) is the leading cause of acquired blindness in U.S. adults. Early detection prevents progression. Screening rates are only 10% in medically underserved populations. METHODS: A statewide telemedicine-based program within primary care centers was implemented to improve DR screening, detection and referrals for underserved patients. STUDY DESIGN: Retrospective, descriptive study. RESULTS: A total of 568 adults were screened during a comprehensive nurse visit from July 2009-June 2010 and had complete data available. Nearly 60% were minorities and 24% were uninsured. A total of 145 cases of DR were identified. The majority were recommended to return in one year for follow-up, while 75 were referred to a specialist. CONCLUSIONS: Telemedicine using digital imaging technology in the primary care office is a strategy that can be used to screen underserved and at-risk patients for DR, increase compliance with screening, and streamline specialist referrals.

[Muscular metastasis from primary lung cancer: about seven cases]. / Métastases musculaires de cancers bronchiques: à propos de sept cas.

Muscular metastasis from primary bronchial carcinoma are rare. We report seven cases with different clinical features. In most cases, these metastasis first manifested as a painful mass and revealed the cancer. Localisation of muscular metastasis was assessed by various imaging techniques (RMI, CT scan and ultrasonography). All cases were assessed by biopsy and were associated with primary adenocarcinoma or undifferentiated large cell carcinoma of the lung. Three patients underwent wide excision, leading to an improvement of general condition. All patients were treated with platinum-based chemotherapy. With reference to our cases, imaging of the metastases will be illustrated and clinical and therapeutic features will be discussed.

Induction of acute lung injury after intranasal administration of toxin botulinum a complex.

The inhalation of aerozolized botulinum toxin may represent a potential significant hazard to both military and civilian personnel. Since the lung is the primary target organ for inhaled toxin, the investigation reported herein was conducted to examine lung function in mice exposed to botulinum toxin A complex by intranasal route. Data includes lethality, symptomatology, measurement of respiratory function (minute ventilation, respiratory frequency, and tidal volume), and histopathology of the lungs. The clinical signs of intoxication are similar to those observed in foodborne botulism. Plethysmography revealed severe impairment of all respiratory parameters tested from 7 hours postexposure. Severe lung lesions, possibly secondary to the intoxication, were observed in mice who survived 14 days after the toxin challenge. These included intra-alveolar hemorrhage and interstitial edema. Mice immunized by the pentavalent (ABCDE) toxoid were protected against the neurotoxin (4 LD50) as revealed by the decrease of lethality and severity of nervous signs of intoxication, but not against histopathological changes in the lungs. These effects are nonspecific and require further experiments in order to specify the relationships between the pathology and the inflammatory process in the lung due to mediators such as cytokines,and possibly permanent physiological sequelae.

Reductive cleavage of demeton-S-methyl by Corynebacterium glutamicum in cometabolism on more readily metabolizable substrates.

Corynebacterium glutamicum is able to biotransform demeton-S-methyl, an organophosphorus compound, during cometabolism with more readily metabolizable substrates. Among the cosubstrates used, fructose is the growth substrate that is most favorable for demeton-S-methyl biotransformation. The reaction mechanism of demeton-S-methyl biotransformation involves reductive cleavage of an S-C bond, which leads to accumulation of dimethyl thiophosphate in the culture medium.

A molecular phylogeny of dinoflagellate protists (pyrrhophyta) inferred from the sequence of 24S rRNA divergent domains D1 and D8.

The sequence of two divergent domains (D1 and D8) from dinoflagellate 24S large subunit rRNA was determined by primer extension using total RNA as template. Nucleotide sequence alignments over 401 bases have been analyzed in order to investigate phylogenetic relationships within this highly divergent and taxonomically controversial group of protists of the division Pyrrhophyta. Data are provided confirming that dinoflagellates represent a monophyletic group. For 11 out of the 13 investigated laboratory grown species, an additional domain (D2) could not be completely sequenced by reverse transcription because of a hidden break located near its 3'-terminus. Two sets of sequence alignments were used to infer dinoflagellate phylogeny. The first [199 nucleotides (nt)] included conservative sequences flanking the D1 and D8 divergent domains. It was used to reconstruct a broad evolutionary tree for the dinoflagellates, which was rooted using Tetrahymena thermophila as the outgroup. To confirm the tree topology, and mainly the branchings leading to closely related species, a second alignment (401 nt) was considered, which included the D1 and D8 variable sequences in addition to the more conserved flanking regions. Species that showed sequence similarities with other species lower than 60% on average (Knuc values higher than 0.550) were removed from this analysis. A coherent and convincing evolutionary pattern was obtained for the dinoflagellates, also confirmed by the position of the hidden break within the D2 domain, which appears to be group specific. The reconstructed phylogeny indicates that the early emergence of Oxyrrhis marina preceded that of most Peridiniales, a large order of thecate species, whereas the unarmored Gymnodiniales appeared more recently, along with members of the Prorocentrales characterized by two thecal plates. In addition, the emergence of heterotrophic species preceded that of photosynthetic species. These results provide new perspectives on proposed evolutionary trees for the dinoflagellates based on morphology, biology, and fossil records.