OBJECTIVETo compare the antimicrobial efficacy of four endodontic irrigants using an in vitro model infected by Enterococcus faecalis (Ef).

METHODSThe root canals of fifty extracted teeth were infected by Ef in vitro. The test groups were irrigated with 3% H(2)O(2), 2.5% sodium hypochlorite (SH), 2% chloramine-T (CR), and 2% chlorhexidine (CHX), respectively, and the control group was irrigated with 0.9% NaCl. The concentration of Ef in canals of each group was calculated before and after irrigation. The residual bacteria within the dentinal tubules and vitalities of the residual bacteria were also examined.

RESULTSAll chemical irrigants were significantly more effective than 0.9% NaCl (P < 0.05); 2.5% SH and 2% CHX were statistically more effective than 3% H(2)O(2) (P < 0.05). Residual bacteria could be found in the dentinal tubules and propagated 72 h after.

CONCLUSIONS2% CR and 2% CHX had almost the equivalent antimicrobial effect as 2.5% SH, but 3% H(2)O(2) was less effective.

Chloramines ; pharmacology ; Chlorhexidine ; pharmacology ; Dental Pulp Cavity ; microbiology ; Enterococcus faecalis ; drug effects ; Humans ; Hydrogen Peroxide ; pharmacology ; In Vitro Techniques ; Root Canal Irrigants ; pharmacology ; Sodium Hypochlorite ; pharmacology ; Tosyl Compounds ; pharmacology

OBJECTIVETo study the resistance of methicillin-resistant staphylococcus aureus (MRSA), an indicator used in hospitals.

METHODSWe used minimal inhibitory concentrations (MIC) of iodoph and chlorhexidine to MRSA, methicillin-sensitive staphylococcus aureus (MSSA) and staphylococcus aureus ATCC6538.

RESULTSObvious difference between MRSA and MSSA the MIC of Iodophor was noticed. Among MICs, 5.3% MRSA strains were 2-folds and 28.9% MRSA strains were 1.5 fold more than staph. aureus ATCC6538, while the MIC of 11.1% MSSA strains raised 1.5 fold than ATCC6538. The MIC of 83.3% MSSA strains were the same to staph. aureus ATCC6538. The MIC of chlorhexidine to MRSA, MSSA and staphylococcus aureus ATTC6538 were similar to each other.

CONCLUSIONResults showed that some MRSA were more resistant to Iodophor than staph. aureus ATCC6538, but remained the same resistance to Chlorhexidine. Thus the concentration of Iodophor should be raised when the resistant strains were isolated.

Anti-Infective Agents ; pharmacology ; Chlorhexidine ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Humans ; Iodophors ; pharmacology ; Methicillin ; pharmacology ; Methicillin Resistance ; Microbial Sensitivity Tests ; Staphylococcus aureus ; drug effects

PURPOSE: The purpose of this study was to compare 1% chlorhexidine-gluconate/61% ethanol (CHG/Ethanol) emollient and 7.5% povidone-iodine (PVI) scrub for antimicrobial,residual effect, and skin condition. METHOD: CHG/Ethanol emollient hand hygiene was performed waterless, and brushless by operating doctors and nurses (N=20). PVI hand washing was performed with water and a brush (N=20) for 5 min. The subjects were asked to press their left hand in hand-shaped agar before a surgical scrub, immediately after a surgical scrub and after the operation. The amount of isolated microorganisms were calculated by counting the number of divided areas(1 X 1 cm, 160 cell) which were culture positive in the hand culture plate. The skin condition was evaluated. RESULT: The antimicrobial count of CHG/Ethanol emollient and PVI immediately post surgical scrub was 0.0 vs. 4.1 (p>.05), and after the operation was 0.1 vs. 37.8 (p>.05)respectively. The Residual effect of CHG/Ethanol emollient immediately post surgical scrub and after the operation were 0.0 vs. 0.1 (p>.05), and PVI were 4.1 vs. 37.8 (p>.05)respectively. The skin condition and satisfaction of CHG/Ethanol emollient was higher than PVI (p<.05). CONCLUSION: The antimicrobial effect between CHG/Ethanol emollient and PVI were the same. Considering skin condition, satisfaction and allergic reaction CHG/Ethanol emollient for surgical scrub is recommended in Korea.
Adult ; Anti-Infective Agents/*pharmacology ; Chlorhexidine/*analogs & derivatives/chemistry/pharmacology ; Colony Count, Microbial ; Ethanol/chemistry/*pharmacology ; Female ; Handwashing ; Humans ; Male ; Microbial Sensitivity Tests ; Povidone-Iodine/chemistry/*pharmacology

OBJECTIVE: To construct a model of Enterococcus faecalis (E. faecalis) infection in dentinal tubules by gradient centrifugation and to evaluate the antibacterial effect of low-temperature plasma on E. faecalis in dentinal tubules. METHODS: Standard dentin blocks of 4 mm×4 mm×2 mm size were prepared from single root canal isolated teeth without caries, placed in the E. faecalis bacterial solution, centrifuged in gradient and incubated for 24 h to establish the model of dentinal tubule infection with E. faecalis. The twenty dentin blocks of were divided into five groups, low-temperature plasma jet treatment for 0, 5 and 10 min, calcium hydroxide paste sealing for 7 d and 2% chlorhexidine gel sealing for 7 d. Scanning electron microscopy and confocal laser scanning microscope were used to assess the infection in the dentinal tubules and the antibacterial effect of low-temperature plasma. RESULTS: The results of scanning electron microscopy and confocal laser scanning microscopy showed that after 24 h of incubation by gradient centrifugation, E. faecalis could fully enter the dentinal tubules to a depth of more than 600μm indicating that this method was time-saving and efficient and could successfully construct a model of E. faecalis infection in dentinal tubules. Low-temperature plasma could enter the dentinal tubules and play a role, the structure of E. faecalis was still intact after 5 min of low-temperature plasma treatment, with no obvious damage, and after 10 min of low-temperature plasma treatment, the surface morphology of E. faecalis was crumpled and deformed, the cell wall was seriously collapsed, and the normal physiological morphology was damaged indicating that the majority of E. faecalis was killed in the dentinal tubules. The antibacterial effect of low-temperature plasma treatment for 10 min exceeded that of the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d. These two chemicals had difficulty entering deep into the dentinal tubules, and therefore only had a few of antibacterial effect on the bacterial biofilm on the root canal wall, and there was also no significant damage to the E. faecalis bacterial structure. CONCLUSION Gradient centrifugation could establish the model of E. faecalis dentin infection successfully. Low-temperature plasma treatment for 10 min could kill E. faecalis in dentinal tubules effectively, which is superior to the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d.
Chlorhexidine/pharmacology* ; Calcium Hydroxide/pharmacology* ; Enterococcus faecalis/physiology* ; Temperature ; Dentin ; Biofilms ; Anti-Bacterial Agents/pharmacology* ; Root Canal Irrigants/pharmacology* ; Dental Pulp Cavity

OBJECTIVETo observe the antimicrobial activity of topical agents commonly used for burns on Acinetobacter baumannii (AB) in both free and biofilm states, and their synergistic effect with ambroxol on AB within biofilm.

METHODSEleven AB strains were isolated from wound excretion, respiratory tract, and blood of patients hospitalized in our hospital from August 2005 to April 2007. (1) The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of mafenide acetate and chlorhexidine acetate to free AB (including drug-resistant, drug-sensitive, and standard strains) were determined by dilution method. (2) AB was cultured with LB or TSB medium for 12, 24, and 48 h to form biofilm, and it was treated with above-mentioned two topical agents in MBC (mafenide group and chlorhexidine group) for 30 min. Biofilm not treated by topical agent was used as control group. The biofilm thickness was determined with confocal laser scanning microscope. The proportion of living bacteria in biofilm was calculated. AB biofilm in each topical agent group was mixed and inoculated into LB culture dish to observe the growth of bacteria. (3) AB was cultured with LB medium for 48 h to form biofilm, which was respectively treated by above-mentioned two topical agents in MBC (mafenide group and chlorhexidine group) and combination of each topical agent with 3.75 mg/mL ambroxol solution (ambroxol + mafenide group and ambroxol + chlorhexidine group) for 30 min. Biofilm not treated by topical agents was used as control group. Growth of bacteria in biofilm was detected with MTT method (denoted as absorbance value). Data were processed with one-way analysis of variance and LSD-t test.

RESULTS(1) MIC of mafenide acetate and chlorhexidine acetate for free AB was respectively 25.00 mg/mL and 0.03 mg/mL. MBC of both agents for free AB was the same as their MIC. (2) Among three groups, the thickness of biofilm of sensitive AB was thicker than that of drug-resistant bacteria at most of the time points. Compared with those in control group, biofilm thickness and proportion of living bacteria in biofilm were slightly decreased in mafenide and chlorhexidine groups. The growth of bacteria was abundant in each group. (3) Absorbance value of drug-resistant bacteria in control, mafenide, and chlorhexidine groups was respectively 0.776 ± 0.071, 0.625 ± 0.063, and 0.420 ± 0.068. Absorbance value of drug-resistant bacteria in ambroxol + mafenide group (0.174 ± 0.089) was significantly lower than that of control group (t = 11.823, P = 0.000) and mafenide group (t = 9.248, P < 0.01). Absorbance value of ambroxol + chlorhexidine group (0.178 ± 0.044) was significantly lower than that of control group (t = 16.009, P = 0.000) and chlorhexidine group (t = 6.681, P < 0.01).

CONCLUSIONSDrug-resistant AB forms biofilm readily, which prevents topical agents from killing the bacteria inside. Combined use of ambroxol with topical agents gives synergistic effect on killing AB in biofilm in the wound.

Acinetobacter baumannii ; drug effects ; isolation & purification ; Anti-Bacterial Agents ; pharmacology ; Biofilms ; drug effects ; Burns ; microbiology ; Chlorhexidine ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Mafenide ; pharmacology ; Microbial Sensitivity Tests

Dentin matrix metalloproteinases (MMPs) are a family of host-derived proteolytic enzymes trapped within mineralized dentin matrix, which have the ability to hydrolyze the organic matrix of demineralized dentin. After bonding with resins to dentin there are usually some exposed collagen fibrils at the bottom of the hybrid layer owing to imperfect resin impregnation of the demineralized dentin matrix. Exposed collagen fibrils might be affected by MMPs inducing hydrolytic degradation, which might result in reduced bond strength. Most MMPs are synthesized and released from odontoblasts in the form of proenzymes, requiring activation to degrade extracellular matrix components. Unfortunately, they can be activated by modem self-etch and etch-and-rinse adhesives. The aim of this review is to summarize the current knowledge of the role of dentinal host-derived MMPs in dentin matrix degradation. We also discuss various available MMP inhibitors, especially chlorhexidine, and suggest that they could provide a potential pathway for inhibiting collagen degradation in bonding interfaces thereby increasing dentin bonding durability.
Chlorhexidine ; pharmacology ; Collagen ; metabolism ; ultrastructure ; Dental Bonding ; Dentin ; enzymology ; ultrastructure ; Dentin-Bonding Agents ; chemistry ; Enzyme Inhibitors ; pharmacology ; Humans ; Hydrolysis ; Matrix Metalloproteinase Inhibitors ; Matrix Metalloproteinases ; metabolism ; Resin Cements ; chemistry

Sensitivity to commercial teat dips (nonoxinol-9 iodine complex and chlorhexidine digluconate) of 56 Staphylococcus (S.) aureus strains isolated from quarter milk samples of various German dairy herds treated with different teat dipping schemes was investigated in this study. The minimum inhibitory concentration was determined using a broth macrodilution method according to the German Veterinary Association guidelines. The main objective of the current study was to induce in vitro resistance induction of S. aureus to chemical disinfectants. Ten different strains were repeatedly passed ten times in growth media with sub-lethal concentrations of disinfectants. Nine strains showed a significant reduction in susceptibility to the nonoxinol-9 iodine complex but only one strain developed resistance to chlorhexidine digluconate. Stability of the acquired resistance was observed in all S. aureus strains adapted to the nonoxinol-9 iodine complex and chlorhexidine digluconate. In contrast, simultaneous resistance to different antibiotics was not observed in any of the ten investigated S. aureus strains. However, the isolates exhibited a high degree of resistance to penicillin G. Based on these results, resistance of S. aureus to chemical disinfectants may be more likely to develop if the chemicals are used at concentrations lower than that required for an optimal biocidal effect.
Animals ; Anti-Bacterial Agents/pharmacology ; Cattle ; Chlorhexidine/*pharmacology ; Disinfectants/pharmacology ; Dose-Response Relationship, Drug ; Drug Resistance, Bacterial ; Female ; Germany/epidemiology ; Iodine/chemistry/*pharmacology ; Mastitis, Bovine/epidemiology/*microbiology ; Nonoxynol/*pharmacology ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus aureus/classification/*drug effects

A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine. The aim of this study was to compare the antimicrobial activity of 1% alexidine with that of 2% chlorhexidine using Enterococcus faecalis-infected dentin blocks. Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each. E. faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2% chlorhexidine or 1% alexidine solutions for 5 and 10 min, respectively. Sterile saline was used as a control. The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope. Significantly fewer bacteria were observed in the 2% chlorhexidine- or 1% alexidine-soaked groups than in the control group (P<0.05). However, there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups (P>0.05). Ruptured or antiseptic-attached bacteria were more frequently observed in the 10-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups. In conclusion, 10-min soaking with 1% alexidine or 2% chlorhexidine can be effective against E. faecalis infection.
Animals ; Anti-Bacterial Agents ; pharmacology ; Bacterial Adhesion ; drug effects ; Bacterial Load ; drug effects ; Biguanides ; pharmacology ; Cattle ; Cell Membrane ; drug effects ; Chlorhexidine ; pharmacology ; Dentin ; microbiology ; Enterococcus faecalis ; drug effects ; Microscopy, Electron, Scanning ; Random Allocation ; Time Factors

BACKGROUNDBlood culture contamination is a significant adverse event. The aim of this project was to evaluate the efficacy of a strict blood collection procedure in reducing the blood culture contamination rate.

METHODSA prospectively controlled study was performed in two different medical areas in Peking Union Medical College Hospital (PUMCH) for 16 months (from May 2006 to September 2007). In test group, a strict blood collection procedure was carried out by trained nurses with the veinpuncture sites were scrupulously disinfected with 2.5% tincture of iodine plus 70% alcohol. In control group, commonly used procedure in PUMCH was performed with 0.45% chlorhexidine acetate plus 0.2% iodine. Blood culture positive results for 4 target organisms (Coagulase-negative staphylococci, Propionibacterium acnes, Corynebacterium species and Bacillus species) were further assessed by physicians from infectious department to determine whether a sample was true positive (pathogen) or false positive (contamination).

RESULTSTotal 9321 blood culture collections were analyzed. The blood culture contamination rate in test group was significantly lower than that in control group (5/3177 (0.16%) vs. 77/6144 (1.25%); χ(2) = 13.382, P < 0.001). The most common contaminant was Coagulase-negative staphylococcus (76.83%). The average cultural time during which contaminated samples became positive was longer than that for true pathogen samples (42.0 hours vs. 13.9 hours, P = 0.041).

CONCLUSIONUsing a strict blood collection procedure can significantly reduce blood culture contamination rate.

Anti-Infective Agents, Local ; pharmacology ; Bacillus ; drug effects ; Blood ; microbiology ; Blood Specimen Collection ; adverse effects ; methods ; Chlorhexidine ; pharmacokinetics ; Corynebacterium ; drug effects ; Disinfection ; methods ; Humans ; Iodine ; pharmacology ; Propionibacterium ; drug effects ; Prospective Studies ; Staphylococcus ; drug effects

Our previous studies showed that biomodification of demineralized dentin collagen with proanthocyanidin (PA) for a clinically practical duration improves the mechanical properties of the dentin matrix and the immediate resin-dentin bond strength. The present study sought to evaluate the ability of PA biomodification to reduce collagenase-induced biodegradation of demineralized dentin matrix and dentin/adhesive interfaces in a clinically relevant manner. The effects of collagenolytic and gelatinolytic activity on PA-biomodified demineralized dentin matrix were analysed by hydroxyproline assay and gelatin zymography. Then, resin-/dentin-bonded specimens were prepared and challenged with bacterial collagenases. Dentin treated with 2% chlorhexidine and untreated dentin were used as a positive and negative control, respectively. Collagen biodegradation, the microtensile bond strengths of bonded specimens and the micromorphologies of the fractured interfaces were assessed. The results revealed that both collagenolytic and gelatinolytic activity on demineralized dentin were notably inhibited in the PA-biomodified groups, irrespective of PA concentration and biomodification duration. When challenged with exogenous collagenases, PA-biomodified bonded specimens exhibited significantly less biodegradation and maintained higher bond strengths than the untreated control. These results suggest that PA biomodification was effective at inhibiting proteolytic activity on demineralized dentin matrix and at stabilizing the adhesive/dentin interface against enzymatic degradation, is a new concept that has the potential to improve bonding durability.
Chlorhexidine ; chemistry ; pharmacology ; Collagenases ; pharmacology ; Dental Bonding ; Dental Cements ; chemistry ; Dental Stress Analysis ; instrumentation ; Dentin ; drug effects ; ultrastructure ; Dentin-Bonding Agents ; chemistry ; Gelatinases ; pharmacology ; Humans ; Hydroxyproline ; analysis ; Matrix Metalloproteinase 8 ; pharmacology ; Matrix Metalloproteinase Inhibitors ; chemistry ; pharmacology ; Proanthocyanidins ; chemistry ; pharmacology ; Stress, Mechanical ; Surface Properties ; Tensile Strength ; Tooth Demineralization ; pathology ; physiopathology