Comparative evaluation of chlorhexidine and cinnamon extract used in dental unit waterlines to reduce bacterial load in aerosols during ultrasonic scaling

Dental unit waterlines (DUWL) are believed to be a source of infection. Ultrasonic instruments generate aerosols with significantly greater numbers of bacteria. Chlorhexidine (CHX) exhibits significant antiseptic effect. Recently, cinnamon (CIN) has been displayed to have antibacterial and anti-inflammatory properties in vivo. Aim: The aim of this study is to compare and evaluate the efficacy of CHX versus CIN extract in the reduction of bacterial count in dental aerosols when used as an irrigant through DUWL during ultrasonic scaling. Materials and Methods: Sixty patients with moderate-to-severe gingivitis were randomly divided into 3 groups of 20 patients each undergoing ultrasonic scaling. For experimental group I, CHX was added in dental unit reservoir before ultrasonic scaling. Similarly, in group II, CIN extract was used and group III served as control where distilled water (DW) was used. The aerosols from ultrasonic units were collected on two blood agar plates at three different positions. One plate from each position was incubated aerobically for 48 h and other plate anaerobically for 72 h. The total number of colony forming units (CFUs) was then calculated and statistically interpreted. Results: CHX and CIN both were equally effective (P > 0.05) in reducing the bacterial count in aerosols as compared to DW (P < 0.05) when used through DUWL. Maximum contamination was seen on the agar plate placed at the chest of the patient. Conclusion: Both CIN and CHX used as an irrigant through DUWL effectively helped in the reduction of bacterial count in dental aerosols.

Nueva técnica difásica en tubo para el diagnóstico de estrongiloidiasis / New diffasic tube technique for the diagnosis of strongyloidiasis

Se realizó un estudio de enteroparásitos en una población indígena, a través del cual se propuso un nuevo procedimiento de diagnóstico para estrongiloidiasis, técnica difásica en tubo (TDT), con el objeto de compararla con la de agar en placa (Arakaki). La metodología consistió en análisis de muestras fecales de 50 individuos mediante examen al fresco, técnica de concentración de Ritchie, técnica de agar en placa y la TDT aquí propuesta. Se obtuvo una prevalencia parasitaria y poliparasitismo elevados, con 94% y 70% respectivamente. Blastocystis spp. (chromista) prevaleció, seguido de Giardia intestinalis, entre los protozoarios, mientras entre los helmintos predominaron los geohelmitos, encabezados por Trichuris trichiura y Strongyloides stercoralis. La sensibilidad y especificidad de la TDT fue 75% y 66,7 %, respectivamente, a las 24 horas de lectura, aislándose la especie 1,5 veces más sobre la técnica tradicional, y de 85,71% y 16,67% a las 48 horas, recuperándose el nemátode 1,6 veces más, mostrando una mayor sensibilidad. No se reportaron casos de estrongiloidiasis a través del examen al fresco, ni por la técnica de Ritchie. Se concluye que la TDT, es más eficaz para diagnóstico de la especie S. stercoralis, tanto a las 24 como a las 48 horas de lectura.

A study of enteroparasites in an indigenous population was carried out, through which a new diagnostic procedure for strongyloidiasis, diphasic technique in tube (DTT), was proposed, in order to compare it with plaque agar (Arakaki). The methodology consisted in the analysis of fecal samples of 50 individuals by means of a fresh test, Ritchie concentration technique, plate agar technique and the DTT proposed here. A high parasitic prevalence and poliparasitism was obtained, with 94% and 70% respectively. Blastocystis spp. (chromist) prevailed, followed by Giardia intestinalis, among the protozoa, while among the helminths the geohelmities predominated, headed by Trichuris trichiura and Strongyloides stercoralis. The sensitivity and specificity of DTT was 75% and 66.7%, respectively, at 24 hours of reading, the species being isolated 1.5 times more on the traditional technique, and 85.71% and 16.67% at 48 hours, recovering the nematode 1.6 times more, showing greater sensitivity. No cases of strongyloidiasis were reported through the fresh examination, nor by the Ritchie technique. It is concluded that DTT, is more effective for diagnosis of the species S. stercoralis, both at 24 and at 48 hours of reading.

Recent Advances in Function-based Metagenomic Screening / 基因组蛋白质组与生物信息学报·英文版

Metagenomes from uncultured microorganisms are rich resources for novel enzyme genes. The methods used to screen the metagenomic libraries fall into two categories, which are based on sequence or function of the enzymes. The sequence-based approaches rely on the known sequences of the target gene families. In contrast, the function-based approaches do not involve the incorporation of metagenomic sequencing data and, therefore, may lead to the discovery of novel gene sequences with desired functions. In this review, we discuss the function-based screening strategies that have been used in the identification of enzymes from metagenomes. Because of its simplicity, agar plate screening is most commonly used in the identification of novel enzymes with diverse functions. Other screening methods with higher sensitivity are also employed, such as microtiter plate screening. Furthermore, several ultra-high-throughput methods were developed to deal with large metagenomic libraries. Among these are the FACS-based screening, droplet-based screening, and the in vivo reporter-based screening methods. The application of these novel screening strategies has increased the chance for the discovery of novel enzyme genes.

Status and Risk Factors of Strongyloides stercoralis Infection in Rural Communities of Xayaburi Province, Lao PDR

The present study was performed to reveal the current status and risk factors of Strongyloides stercoralis infections in the villages of Kenethao district, Xayaburi Province, Lao PDR. Fecal specimens were collected and examined for S. stercoralis using Koga-agar plate culture technique. Among 516 individuals, the prevalence of S. stercoralis and hookworm infection was 44.2% and 17.1%, respectively. Co-infection was detected in 13.2% of the cases. The prevalence did not significantly differ between males and females (P=0.193). However, the prevalence of S. stercoralis infection increased significantly with age (P=0.041). Of the risk factors examined, both performing farming activities (P=0.001) and walking barefoot when going outside of the house (P=0.003) showed significant correlations with S. stercoralis infections. Our results suggest that S. stercoralis is highly endemic in this area. The National Helminth Control Program of Lao PDR should take actions to control S. stercoralis infection. In addition, provision of health education about the benefits of wearing shoes would be important for reducing infection in the study area. Moreover, the application of high-sensitivity diagnostic approaches is needed to obtain the true impact of S. stercoralis infections in all rural communities in order to provide surveillance activities in Lao PDR.

Campylobacter in broiler slaughter samples assessed by direct count on mCCDA and Campy-Cefex agar

ABSTRACT Campylobacter spp. cause foodborne illnesses in humans primarily through the consumption of contaminated chicken. The aim of this study was to evaluate the United States Department of Agriculture's (USDA) recommended methodology, protocol MLG 41.02, for the isolation, identification and direct plate counting of Campylobacter jejuni and C. coli samples from the broiler slaughtering process. A plating method using both mCCDA and Campy-Cefex agars is recommended to recover Campylobacter cells. It is also possible to use this method in different matrices (cloacal swabs and water samples). Cloacal swabs, samples from pre-chiller and post-chiller carcasses and samples of pre-chiller, chiller and direct supply water were collected each week for four weeks from the same flock at a slaughterhouse located in an abattoir in southern Brazil. Samples were analyzed to directly count Campylobacter spp., and the results showed a high frequency of Campylobacter spp. on Campy-Cefex agar. For the isolated species, 72% were identified as Campylobacter jejuni and 38% as Campylobacter coli. It was possible to count Campylobacter jejuni and Campylobacter coli from different samples, including the water supply samples, using the two-agar method. These results suggest that slaughterhouses can use direct counting methods with both agars and different matrices as a monitoring tool to assess the presence of Campylobacter bacteria in their products.

Modified Formalin-Ether Concentration Technique for Diagnosis of Human Strongyloidiasis

We compared the efficacy and applicability of a modified formalin-ether concentration technique (M-FECT) to the conventional FECT (C-FECT) and the agar plate culture (APC) method for the detection of Strongyloides stercoralis larvae. For this purpose, we used 600 human fecal specimens collected in an endemic area of southern Thailand. In the M-FECT, we used 2 layers of wire meshes, instead of gauze, to avoid the loss by absorption/adhesion of larvae to the gauze during filtration, and we reduced the exposure time of S. stercoralis larvae in stool samples to formalin. By such simple modifications, the efficacy of M-FECT has become comparable to APC and was much better than that of C-FECT for the diagnosis of strongyloidiasis.

Antibiotic Susceptibility Test of Neisseria gonorrhoeae by Disc Diffusion Method and Its Correlaction with Agar Plate Dilution Method / 대한피부과학회지

In this study, we compared the MIC by agar plate dilution method with the inhibition zone diameters by ordinary disc diffusion method and 24 hr-prediffusion disc method on five antibiotics, respectively. The results were summarized as follows; 1. The agar plate dilution method and the ordinary disc diffusion method gave a satisfactory degree of correlation by linear regression. The correlation coeffecients were highly significant for penicillin (r= -0.88) and ampicillin(r = -0.91) but less significant for tetracyclin(r= -0.34), kanamycin(r= -0.55) and spectinomycin (r = -0.46). 2. Between the agar plate dilution method and the 24 hour-prediffusion disc method the correlation coeffecients were highly significant for penicillin(r= -0.9) and ampicillin (r= -0.91) but less so for tetracyclin(r= -0.4), kanamycin (r=-0.57) and spectinomycin(r=-0.5), 3. In relation to the MIC values by agar pate dilution method, the correlation coefficients were slightly higher and the slopes of linear regression were steeper for the 24 hour-prediffusion disc method than the ordinary disc diffusion method, but the differences were statistically not significant.