Physical, chemical and microbiological characterization of the intertidal sediments of Pereque Beach, Guaruja (SP), Brazil

Physical and chemical characteristics of intertidal sediments and their relationships with bacteria and cyanobacteria, were analyzed at four stations at Pereque Beach. Granulometric analysis showed that Pereque beach has sediment that is classified as sand. The lowest value of the sediment C/N rates (6.08), mainly due to a higher concentration of organic nitrogen, was found at the northern part of Pereque Beach, where organic matter of marine source was more prominent. In this area, density (9.6 x 106 cells cm(-3)), biomass (1992.04 ngC cm(-3)) and activity of bacteria were higher than at the southern end. In contrast, cyanobacteria density varied from 2.0 to 4.0 x 10(5) cells cm(-3), with biomass and total chlorophyll a of the sediment being higher at the southern part, where there are water input from Pereque River and higher organic matter of continental origin. The variability in the microbial population is discussed in the light of the sediment granulometry, organic matter quality, fresh water inflow and pollution. (c) 2007 Elsevier Ltd. All rights reserved.

Comparison of hexamethyidisilazane and critical point drying treatments for SEM analysis of anaerobic biofilms and granular sludge

We present a fast procedure for scanning electron microscopy (SEM) analysis in which hexamethyldisilazane (HMDS) solvent, instead of the critical point drying, is used to remove liquids from a microbiological specimen. The results indicate that the HMDS solvent is suitable for drying samples of anaerobic cells for examination by SEM and does not cause cell structure disruption.

Survey of the Microbiological Quality of Nonalcoholic Carbonated Beverages

The number and the main groups of microorganisms present in samples of different nonalcoholic carbonated beverages (lemon, orange and guaraná soft drinks) obtained from a small factory were analyzed. The samples were obtained at the end of the processing line. They were then divided into two lots: one was sent to immediate analysis, the other was stored at environmental temperature for 90 d thereafter it was submitted to the same analysis. Aliquots of 1 mL were drawn from the various samples and the corresponding decimal dilutions were prepared. They were then grown in culture media and counts of mesophilic aerobic bacteria, molds and yeasts, acid-producing bacteria, total and fecal coliforms were taken. It was observed that, of all the analyzed samples, at time 0 or after storage sample C (orange) was the best, since it conformed to the microbiological standards established by legislation. The guaraná type could also be consumed on day zero; the lemon type was inadequate for consumption of all the analyzed samples, the orange type was the only one that could be consumed within 3 months of storage.

Subgingival utilization of a 1% chlorhexidine collagen gel for the treatment of periodontal pockets. A clinical and microbiological study.

This study evaluates the effect of subgingival irrigation with a 1% chlorhexidine collagen gel in periodontal pockets as an adjunct procedure to scaling and root planing (SRP). Thirty-seven sites with probing depth (PD) of 5-7 mm and BANA positive in 6 patients with chronic periodontal disease were selected. Sites were assigned to different treatment groups consisting of SRP only (group 1), SRP + irrigation with collagen gel (group 2), or SRP + irrigation with collagen gel containing 1% chlorhexidine (group 3). Subgingival irrigation was performed after initial SRP and at 7, 14 and 21 days. Clinical measurements including PD, plaque index (PI), gingival index (GI), gingival recession (GI), bleeding on probing (BOP) and clinical attachment level (CAL) were performed at the selected sites at baseline, 60 and 90 days and the BANA test was performed on plaque samples from the same sites at baseline and 90 days. There was an improvement in clinical parameters in all groups with a significantly greater decrease in GI and bleeding in the chlorhexidine group. There was a greater reduction of BANA positive sites in groups 2 and 3. The authors concluded that 1% chlorhexidine collagen gel is a promising adjunct to SRP in the treatment of adult periodontitis.

Use of aspartate aminotransferase in diagnosing periodontal disease: a comparative study of clinical and microbiological parameters

The objective of this study was to assess the association between the levels of enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) with the BANA hydrolysis microbiological test (Perioscan) and clinical periodontal diagnostic measurements, such as bleeding on probing, plaque index, gingival index, probing depth, and attachment level in patients with chronic periodontitis using an enzymatic test (PocketWatch). One hundred and forty-seven sites were evaluated in 22 patients with a probing depth of > or = 5 mm at selected sites. AST and BANA enzymatic tests were carried out, and clinical parameters recorded. Pearson's chi-square and Fisher's exact tests were used for statistical analysis. There was no statistical correlation between AST levels and any of the analyzed parameters. The lack of any association between the factors studied does not indicate, however, that the latter cannot be used in diagnosing the actual periodontal condition of patients and/or sites. However, more research should be carried out to evaluate the true relationship between AST and periodontal disease.

Microbiologic and radiographic analysis of ligature-induced peri-implantitis with different dental implant surfaces

Purpose: The goal of this study was to evaluate microbiota and radiographic peri-implant bone loss associated with ligature-induced peri-implantitis. Materials and Methods: Thirty-six dental implants with 4 different surfaces (9 commercially pure titanium, 9 titanium plasma-sprayed, 9 hydroxyapatite, and 9 acid-etched) were placed in the edentulous mandibles of 6 dogs. After 3 months with optimal plaque control, abutment connection was performed. On days 0, 20, 40, and 60 after placement of cotton ligatures, both microbiologic samples and periapical radiographs were obtained. The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Campylobacter spp, Capnocytophaga spp, Fusobacterium spp, beta-hemolytic Streptococcus, and Candida spp were evaluated culturally. Results: P intermedia/nigrescens was detected in 13.89% of implants at baseline and 100% of implants at other periods. P gingivalis was not detected at baseline, but after 20 and 40 days it was detected in 33.34% of implants and at 60 days it was detected in 29.03% of dental implants. Fusobacterium spp was detected in all periods. Streptococci were detected in 16.67% of implants at baseline and in 83.34%, 72.22%, and 77.42% of implants at 20, 40, and 60 days, respectively. Campylobacter spp and Candida spp were detected in low proportions. The total viable count analysis showed no significant differences among surfaces (P = .831), although a significant difference was observed after ligature placement (P < .0014). However, there was no significant qualitative difference, in spite of the difference among the periods. The peri-implant bone loss was not significantly different between all the dental implant surfaces (P = .908). Discussion and Conclusions: These data suggest that with ligature-induced peri-implantitis, both time and periodontal pathogens affect all surfaces equally after 60 days.

Systemic use of metronidazole in the treatment of chronic periodontitis: a pilot study using clinical, microbiological, and enzymatic evaluation

The aim of the present parallel, double-blind investigation was to evaluate the effect of using systemic metronidazole alone or associated to scaling and root planing on adult chronic periodontal disease, monitored at baseline, 30, 60 and 90 days. Twelve subjects were divided into three groups: the first group (Group I - 22 sites) was submitted to scaling and root planing (SRP) alone; the second group (Group II - 30 sites) received SRP and 250 mg of metronidazole (3 times a day for 10 days), and the third group (Group III - 31 sites) was treated with metronidazole alone. The clinical parameters evaluated were probing depth (PD), clinical attachment level (CAL), plaque index (PlI), gingival index (GI) and bleeding upon probing (BP). Microbiological (BANA test) and enzymatic (Pocket Watch) tests were also performed. All three proposed treatments produced significant improvements in clinical conditions of subjects, from baseline, 30, 60 and 90-day period, except for clinical attachment level. The results obtained by microbiological and enzymatic tests did not show statistical differences among the groups for the 90-day period (r = 0.7924 and r = 0.7757, respectively). In relation to clinical parameters, statistical differences among groups were observed only for the gingival index (p = 0.0261) between Groups I and II, and probing depth (p = 0.0124) between Group I and the others. We conclude that the use of systemic metronidazole did not produce additional effects on the microbiological conditions of these patients with chronic periodontal disease.

Microbiological assay for the determination of azithromycin in ophthalmic solutions

The validation of a simple, sensitive and specific agar diffusion bioassay, applying cylinder-plate method, for the determination of the antibiotic azithromycin in ophthalmic solutions is described. Using a strain of Bacillus subtilis ATCC 9372 as the test organism, azithromycin at concentrations ranging from 50.0 to 200.0 μg·mL-1 could be measured in 1.666 7 mg·mL-1 ophthalmic solutions. A prospective validation of the method showed that the method was linear (r = 0.999 9) and precise (RSD = 0.70) and accurate (it measured the added quantities). The results obtained by bioassay method could be statistically calculated by linear parallel model and by means of regression analysis and verified using analysis of variance (ANOVA). We conclude that the microbiological assay is satisfactory for quantification of azithromycin in ophthalmic solutions.

Methods of experimental induction of periapical inflammation. Microbiological and radiographic evaluation

Aim: To evaluate the influence of coronal filling and apical perforation on the induction of periapical inflammation. Methodology: Fifty-eight root canals in the teeth of dogs were divided into four groups. Groups I and II: root canals were exposed for 180 days; groups III and IV: root canals were exposed for 7 days and then the access cavity filled for 53 days. The root apices of groups I and III were perforated after the coronal opening, whilst those of groups II and IV remained intact. Standard radiographs were taken before and after the experimental periods. Digital images of the radiographs were created and then analysed by three examiners. After induction of periapical inflammation, the root canal contents were collected using paper points. Microbiologic evaluation of the type of microorganism was carried out by culture in different growth media. The radiographic and microbiologic data were statistically analysed using ANOVA at a 5% significance level. Results: There were a greater total number of microorganisms in groups I and II (P < 0.05). The number of anaerobes was greater than the number of aerobes (P < 0.05). The size of the periapical radiolucencies were not significantly different between the experimental groups. Conclusions: The different methods analysed induced similar areas of periapical radiolucency in dogs with predominantly anaerobic bacteria. However, the time required for induction was less when the method with coronal filling was used. © 2005 International Endodontic Journal.

In vivo microbiological evaluation of the effect of biomechanical preparation of root canals using different irrigating solutions

The aim of this study was to evaluate the antimicrobial effect of biomechanical preparation using different irrigating solutions. Seventy-eight root canals from premolars of four dogs were used. After experimental induction of periapical lesions, the root canals were prepared using the following solutions for irrigation: Group 1) 2.5% sodium hypochlorite (NaOCl); Group 2) 2% chlorhexidine (CHX); Group 3) saline solution and Group 4) control group with no biomechanical preparation. The microbiological evaluation of the root canals was performed by counting the colony forming units (CFUs) using different culture mediums. Two absorbent paper cones were used in each root canal in order to collect the microbiological samples before, and thirty days after the biomechanical preparation. The culture plates were incubated in aerobic, anaerobic and microaerophilic environment. Statistical evaluation was carried out using analysis of variance, Tukey and Student tests. The results demonstrated that there was reduction in the number of microorganisms in the NaOCl and CHX groups (p<0.05). There was greater effectiveness in the chlorhexidine group. The group that used saline solution and the control group presented an increased number of microorganisms. It can be concluded that the use of antimicrobial irrigating solutions during biomechanical preparation promotes the reduction of endodontic microbiota. However, a considerable number of microorganisms were still observed.

Antimicrobial analysis of chlorhexidine gel and intracanal medicaments against microorganisms inoculated in root canals

The aim of this paper was to evaluate the antimicrobial activity of 2% chlorhexidine gel (CLX) associated with various intracanal medicaments against Candida albicans and Enterococcus faecalis inoculated in root canals. Thirty six human single-rooted teeth were contaminated with C.albicans and E.faecalis. The canals were instrumented using 2% CLX gel and were divided into three groups according to the intracanal medicaments (ICM) used. Group 1: calcium hydroxide paste [Ca(OH)], Group 2: 2% chlorhexidine gel (CLX) and Group 3: 2% CLX gel + Ca(OH). The root canal collections were performed after 21 days of contamination (control collection), after instrumentation (1st collection), after 14 days of intracanal medicament (2nd collection) and 7 days after medicament removal (3rd collection). The microbiological samples were plated in culture media and incubated for 48 hours. The results were submitted to Kruskal-Wallis test (P ≤ 0.05). It was verified that the instrumentation with CLX reduced the number of CFU/ml significantly when compared with the confirmation collection (control). However, the use of the ICM was only capable to eliminate completely the microorganisms in the root canals without difference statistics between them. Although the use of 2% chlorherixidine gel reduces the number of microorganisms significantly, only the ICM calcium hydroxide and calcium hydroxide associated with chlorhexidine are able to eliminate these microorganisms completely.

Development and validation of a microbiological agar assay for determination of orbifloxacin in pharmaceutical preparations

Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.9992) in the selected range of 16.0-64.0 μg/mL, precise with relative standard deviation (RSD) of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%). The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Development and validation of a successful microbiological agar assay for determination of ceftriaxone sodium in powder for injectable solution

Ceftriaxone sodium is a cephalosporin with broad-spectrum antimicrobial activity and belongs to the third generation of cephalosporins. Regarding the quality control of medicines, a validated microbiological assay for the determination of ceftriaxone sodium in powder for injectable solution has not been reported yet. This paper reports the development and validation of a simple, accurate and reproducible agar diffusion method to quantify ceftriaxone sodium in powder for injectable solution. The assay is based on the inhibitory effect of ceftriaxone sodium on the strain of Bacillus subtilis ATCC 9371 IAL 1027 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.999) in the selected range of 15.0-60.0 μg/mL, precise with a relative standard deviation (RSD) of repeatability intraday = 1.40%, accurate (100.46%) and robust with a RSD lower than 1.28%. The results demonstrated the validity of the proposed bioassay, which allows reliable ceftriaxone sodium quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of a series of cobalt(II) sulfonamide complexes: Synthesis, spectroscopic characterization, and microbiological evaluation against M. tuberculosis. Crystal structure of [Co(sulfamethoxazole)2(H 2O)2]·H2O

Nowadays, the research for new and better antimicrobial compounds is an important field due to the increase of immunocompromised patients, the use of invasive medical procedures and extensive surgeries, among others, that can affect the incidence of infections. Another big problem associated is the occurrence of drug-resistant microbial strains that impels a ceaseless search for new antimicrobial agents. In this context, a series of heterocyclic- sulfonamide complexes with Co(II) was synthesized and characterized with the aim of obtaining new antimicrobial compounds. The structural characterization was performed using different spectroscopic methods (UV-Vis, IR, and EPR). In spite of the fact that the general stoichiometry for all the complexes was Co(sulfonamide)2·nH2O, the coordination atoms were different depending on the coordinated sulfonamide. The crystal structure of [Co(sulfamethoxazole)2(H2O)2]·H 2O was obtained by X-ray diffraction showing that Co(II) is in a slightly tetragonal distorted octahedron where sulfamethoxazole molecules act as a head-to-tail bridges between two cobalt atoms, forming polymeric chains. Besides, the activity against Mycobacterium tuberculosis, one of the responsible for tuberculosis, and the cytotoxicity on J774A.1 macrophage cells were evaluated. © 2012 Elsevier B.V. All rights reserved.