Increased ompW and ompA expression and higher virulence of Acinetobacter baumannii persister cells.

Background: Acinetobacter baumannii is one of the main causes of healthcare-associated infections that threaten public health, and carbapenems, such as meropenem, have been a therapeutic option for these infections. Therapeutic failure is mainly due to the antimicrobial resistance of A. baumannii, as well as the presence of persister cells.

Effect of gastric acid on the surface roughness and bacterial adhesion of bulk-fill composite resins.

The purpose of this in vitro study was to evaluate the effect of gastric acid on the surface roughness and biofilm formation of bulk-fill composite resins. Twenty-seven samples of each composite resin were obtained: G1: Filtek Z250 XT (Z250), G2: Filtek Bulk Fill (FTK), G3: Tetric N-Ceram Bulk Fill (TTC), and G4: Aura Bulk Fill (AUR). The samples were quantitatively analyzed for surface roughness (Ra) using a roughness tester (n=15) and for biofilm formation (Cn) by the counting of colony-forming units (CFUs/mL) (n=9) in three different moments: after polishing (Ra0 and Cn0), after gastric acid immersion (Ra1 and Cn1), and after gastric acid and simulated tooth brushing (Ra2 and Cn2).

Novel 4-aminoquinolines: Synthesis, inhibition of the Mycobacterium tuberculosis enoyl-acyl carrier protein reductase, antitubercular activity, SAR, and preclinical evaluation.

Herein a series of 4-aminoquinolines were synthesized in an attempt to optimize and study the structural features related to LABIO-17 biological activity, a Mycobacterium tuberculosis NADH-dependent enoyl-acyl carrier protein reductase (MtInhA) inhibitor previously identified by a virtual-ligand-screening approach. Structure-activity relationships led to novel submicromolar inhibitors of MtInhA and potent antitubercular agents. The lead compound is 87-fold more potent as enzymatic inhibitors and 32-fold more potent against M.

Copper-coated hospital surfaces: reduction of total bacterial loads and resistant Acinetobacter spp.

Healthcare-associated infections (HAIs) represent a global challenge and an even more staggering concern when related to microorganisms capable of resisting and surviving for long periods in the environment, such as Acinetobacter spp. Strategies that allow a reduction of pathogens from hospital environments represent an additional barrier in infection control protocols, minimizing transmission to hospitalized patients. Considering the antimicrobial properties of copper, here, the bacterial load and the presence of Acinetobacter spp.

Benefits and Challenges of the Use of Two Novel vB_Efa29212_2e and vB_Efa29212_3e Bacteriophages in Biocontrol of the Root Canal Infections.

Unlabelled: Bacteriophage therapy has emerged as a strategy supplementing traditional disinfection protocols to fight biofilms. The aim of the study was to isolate the phages against and to characterize its biological features, morphology, and lytic activity in a formed biofilm model.

Methods: ATCC 29212 strain was used for the trial.

Antitubercular Activity of Novel 2-(Quinoline-4-yloxy)acetamides with Improved Drug-Like Properties.

Using cycloalkyl and electron-donating groups to decrease the carbonyl electrophilicity, a novel series of 2-(quinoline-4-yloxy)acetamides was synthesized and evaluated as inhibitors of (Mtb) growth. Structure-activity relationship studies led to selective and potent antitubercular agents with minimum inhibitory concentrations in the submicromolar range against drug-sensitive and drug-resistant Mtb strains. An evaluation of the activity of the lead compounds against a spontaneous mutant strain indicated that the structures targeted the cytochrome complex.

Osteoblastic Cell Behavior and Early Bacterial Adhesion on Macro-, Micro-, and Nanostructured Titanium Surfaces for Biomedical Implant Applications.

Purpose: Surface treatments may significantly affect physical-chemical properties and surface biologic responses. This study aimed to investigate the influence of alterations in the physical-chemical properties of pure titanium with different surface topographies on biocompatibility and early microbiologic response.

Materials And Methods: Titanium disks were exposed to five different surface treatments created through acid etching and anodizing methods.

The topical effect of chlorhexidine and povidone-iodine in the repair of oral wounds. A review.

Purpose: The aim of this paper was to review the current literature with regard to the use of chlorhexidine and povidone-iodine in the treatment of oral wounds.

Background: Oral mucosa is continuously subjected to physical or chemical injuries, where it becomes a common site for the occurrence of ulcerated lesions. These lesions are susceptible to infections that may delay healing.

Salmonella enterica persister cells form unstable small colony variants after in vitro exposure to ciprofloxacin.

Persistence phenotype and small colony variants (SCVs) can be part of a bacterial bet-hedging strategy for survival under environmental stresses, such as antimicrobial exposure. These phenotypes are of particular concern in persistent and relapsing infections, since cells resume to normal growth after cessation of the stressful condition. In this context, we found persisters and unstable SCVs as phenotypic variants of Salmonella enterica that were able to survive ciprofloxacin exposure.

Antibacterial potential associated with drug-delivery built TiO nanotubes in biomedical implants.

The fast evolution of surface treatments for biomedical implants and the concern with their contact with cells and microorganisms at early phases of bone healing has boosted the development of surface topographies presenting drug delivery potential for, among other features, bacterial growth inhibition without impairing cell adhesion. A diverse set of metal ions and nanoparticles (NPs) present antibacterial properties of their own, which can be applied to improve the implant local response to contamination. Considering the promising combination of nanostructured surfaces with antibacterial materials, this critical review describes a variety of antibacterial effects attributed to specific metals, ions and their combinations.

Bacteriophages in Dentistry-State of the Art and Perspectives.

Bacteriophages, viruses capable of killing bacteria, were discovered in 1915, but the interest in their study has been limited since the advent of antibiotics. Their use in dentistry is still very limited. The authors reviewed studies about bacteriophage structure, mode of action, uses in oral health, and possible future uses in dentistry associated with their possible action over biofilm, as well as the advantages and limitations of phage therapy.

Antimicrobial efficacy of 0.5% peracetic acid and EDTA with passive ultrasonic or manual agitation in an Enterococcus faecalis biofilm model.

We compared the antimicrobial efficacy of EDTA and 0.5% peracetic acid (PAA), with manual agitation (MA) or passive ultrasonic irrigation (PUI) in an Enterococcus faecalis biofilm model. Fifty-five single-rooted human premolar teeth were chemo-mechanically prepared and inoculated with E.

Topical chlorhexidine, povidone-iodine and erythromycin in the repair of traumatic ulcers on the rat tongue: Clinical, histological and microbiological evaluation.

Objective: This study investigated the effect of topical application of 0.12% chlorhexidine, 10% povidone-iodine and 50% erythromycin on the optimization of healing process of traumatic ulcers made on ventral tongue of rats.

Design: Forty-Eight Wistar rats were randomly divided into four groups: control, chlorhexidine (Chx), povidone-iodine (PvI) and erythromycin (Er).

Levels of persisters influenced by aeration in Acinetobacter calcoaceticus-baumannii.

Aim: To evaluate the influence of aeration on persister levels from Acinetobacter calcoaceticus-baumannii isolates exposed to meropenem or tobramycin, as well as analyze morphological and structural changes in persisters.

Materials & Methods: Levels of persisters were determined after a 48-h exposure to tobramycin or meropenem under aerated or static conditions, and persisters were analyzed by scanning and transmission electron microscopy.

Results: The fractions of persisters varied between isolates.

In vitro evaluation of hydrolytic enzyme activity and biofilm formation of Candida parapsilosis species complex from a nosocomial environment.

Introduction:: Candida parapsilosis complex species, frequently found in hospital environments, have gained importance as etiological agents of candidemia.

Methods:: Candida parapsilosis complex isolates from a nosocomial environment were identified and their hydrolitic enzyme activity and ability to form biofilm were characterized.

Results:: Twenty-two C.

Phenotypic Changes Exhibited by Cultured in Space.

Bacteria will accompany humans in our exploration of space, making it of importance to study their adaptation to the microgravity environment. To investigate potential phenotypic changes for bacteria grown in space, was cultured onboard the International Space Station with matched controls on Earth. Samples were challenged with different concentrations of gentamicin sulfate to study the role of drug concentration on the dependent variables in the space environment.

Carbapenem-resistant Acinetobacter baumannii contamination in an intensive care unit.

Introduction:: Acinetobacter baumannii is a major pathogen causing infections in intensive care units (ICUs). In this study, we aimed to evaluate the presence of A. baumannii in an ICU environment and gloves from ICU workers and to characterize the antimicrobial resistance of the isolates in comparison with those isolated from ICU patients at the same hospital.

Histopathological, Microbiological, and Radiographic Analysis of Antimicrobial Photodynamic Therapy for the Treatment of Teeth with Apical Periodontitis: A Study in Rats' Molars.

Objective: The aim of this study was to evaluate in vivo, by histological and radiographic analysis, the response of apical tissues of rats' teeth with experimentally induced apical periodontitis, after one- and two-session endodontic treatment with and without photodynamic therapy (PDT). A microbiological analysis was also performed to verify bacterial reduction after each treatment.

Background Data: Studies carried out in recent years highlighted the antibacterial potential of PDT when associated with conventional endodontic therapy in vitro.

Effects of meropenem exposure in persister cells of Acinetobacter calcoaceticus-baumannii.

Aim: To evaluate the influence of meropenem in the Acinetobacter calcoaceticus-baumannii (ACB) persister levels.

Methods: Persister levels in planktonic and biofilm cultures from ACB isolates were evaluated after exposure to different meropenem concentrations.

Results: A high variability of persister fractions was observed among the isolates cultured under planktonic and biofilm conditions.

Heterogeneous persister cells formation in Acinetobacter baumannii.

Bacterial persistence is a feature that allows susceptible bacteria to survive extreme concentrations of antibiotics and it has been verified in a number of species, such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus spp., Mycobacterium spp. However, even though Acinetobacter baumannii is an important nosocomial pathogen, data regarding its persistence phenotype are still lacking.

A specific polymerase chain reaction method to identify Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia is a multidrug-resistant nosocomial pathogen that is difficult to identify unequivocally using current methods. Accordingly, because the presence of this microorganism in a patient may directly determine the antimicrobial treatment, conventional polymerase chain reaction (PCR) and real-time PCR assays targeting 23S rRNA were developed for the specific identification of S. maltophilia.

Effectiveness of the proton pump inhibitor omeprazole associated with calcium hydroxide as intracanal medication: an in vivo study.

Introduction: The objective of this study was to evaluate the efficacy of the association of a proton pump inhibitor (omeprazole) with Ca(OH)(2) as intracanal medication in a rat model of periapical lesions.

Methods: Periapical lesions were induced on the first right mandibular molar tooth of 36 male Wistar rats (6 per group). After 28 days, the distal canal of each tooth was prepared, filled with the respective dressing (negative control group, PEG 400; positive control group, Ca(OH)(2) + PEG400; test group, Ca(OH)(2) + omeprazole + PEG 400), and sealed with amalgam for 15 or 28 days.

Effect of ultrasonics on Enterococcus faecalis biofilm in a bovine tooth model.

Introduction: The purpose of this study was to evaluate in vitro the effect of the ultrasonic irrigation of sodium hypochlorite and EDTA in root canals of bovine teeth infected with Enterococcus faecalis.

Methods: Eighty-four bovine incisors were inoculated with E. faecalis, remaining in culture for 50 days for biofilm formation.

Identification of Candida spp. by phenotypic tests and PCR.

The correct identification of Candida species is of great importance, as it presents prognostic and therapeutical significance, allowing an early and appropriate antifungical therapy. The purpose of this study was to identify isolates of Candida spp. from oral mucosa of 38 patients with oral candidosis evaluated in 2004 by phenotypic methods and PCR, discriminating C.