Potential for nosocomial transmission of Enterococcus faecalis from surfaces in dental operatories.

AIM: To assess the potential for nosocomial transmission of Enterococcus faecalis during root canal treatment by measuring its occurrence on surfaces in dental operatories in relation to the efficacy of disinfection routines. METHODOLOGY: Eight dental clinics (two endodontic specialist clinics and six general dentistry clinics) were included. Bacterial sampling was conducted in duplicate after root canal treatment and collected before and after disinfection from four surfaces expected to be frequently disinfected and six surfaces expected to be occasionally disinfected. RESULTS: A total of 320 samples were collected. Overall, 40.6% (n = 130) exhibited bacterial growth, mostly consisting of environmental bacteria (36.3%) and to a lesser extent of bacteria from salivary contamination (3.4%). Only three surfaces, all of which were probably seldomly disinfected, were positive for E. faecalis (0.9%). Disinfection routines resulted in an increased contamination in the majority of general dentistry clinics: 64% (32/50) of the surfaces were contaminated prior to and 70% (35/50) after disinfection. Conversely, disinfection of surfaces in the specialist clinics reduced contamination levels by 10%. CONCLUSIONS: The origin of E. faecalis in secondary root canal infections remains unclear, as the potential for nosocomial transmission of enterococci from environmental surfaces in dental surgeries appears to be very small. The incorrect or ineffective disinfection procedures in general dentistry clinics needs to be addressed to counteract the risk for bacterial transmission in dental operatories.

In vitro activity of ABT-492 against anaerobic bacteria.

The purpose of the study was to determine the in vitro activity of ABT-492 compared with that of other antimicrobial agents against anaerobic bacteria. The activity of ABT-492 was investigated against 369 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of moxifloxacin, piperacillin, cefoxitin, imipenem, clindamycin and metronidazole. ABT-492 and imipenem were the most active antimicrobial agents tested.

In vitro activity of ABT-773 against anaerobic bacteria.

The purpose of the study reported here was to determine the in vitro activity of ABT-773 compared with that of other antimicrobial agents against anaerobic bacteria. The activity of ABT-773 was investigated against 354 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of azithromycin, clarithromycin, roxithromycin, erythromycin, cefoxitin, imipenem, clindamycin and metronidazole. ABT-773 and imipenem were the most active antimicrobial agents tested.

In vitro activity of LY 333328 against anaerobic gram-positive bacteria.

LY 333328 is a new semisynthetic glycopeptide with reported activity against aerobic Gram-positive cocci such as enterococci, pneumococci, streptococci and staphylococci. The present investigation was undertaken to determine the in vitro activity of LY 333328 against 178 Gram-positive anaerobic bacteria recently isolated from human infections. The activity was compared with that of vancomycin, teicoplanin, cefoxitin, imipenem, clindamycin and metronidazole. Peptostreptococci (48 strains): LY 333328, range 0.016-1.0 mg/l; vancomycin, 0.125-2.0 mg/l; teicoplanin, 0.032-2.0 mg/l; cefoxitin, 0.064-8.0 mg/l; imipenem, 0.016-0.064 mg/l; clindamycin, 0.016-1.0 mg/l; metronidazole, 0.125-8.0 mg/l. Propionibacterium acnes (31 strains): LY 333328, range 0.032-0.125 mg/l; vancomycin, 0.25-0.5 mg/l; teicoplanin, 0.25-0.5 mg/l; cefoxitin, 0.125-1.0 mg/l; imipenem, 0.032-0.064 mg/l; clindamycin, 0.016-0.064 mg/l; metronidazole, 32-> or =64 mg/l. Clostridium difficile (50 strains): LY 333328, range 0.016-2.0 mg/l; vancomycin, 0.5-4.0 mg/l; teicoplanin, 0.064-0.5 mg/l; cefoxitin, 64-128 mg/l; imipenem, 8.0 mg/l; clindamycin, 0.25-128 mg/l; metronidazole, 0.125-0.25 mg/l. Clostridium perfringens (49 strains): LY 333328, range 0.016-2.0 mg/l; vancomycin, 0.025-4.0 mg/l; teicoplanin, 0.064-4.0 mg/l; cefoxitin, 0.5-1.0 mg/l; imipenem, 0.016-0.5 mg/l; clindamycin, 0.008-1.0 mg/l; metronidazole, 1.0-4.0 mg/l. LY 333328 had an excellent in vitro activity against anaerobic Gram-positive bacteria.

In vitro activity of HMR 3647 against anaerobic bacteria.

The aim of the present investigation was to determine the in vitro activity of HMR 3647 compared with other antimicrobial agents against anaerobic bacteria. The activity of HMR 3647 was determined against 342 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with azithromycin, clarithromycin, roxithromycin, erythromycin, cefoxitin, imipenem, clindamycin and metronidazole. Among the macrolides HMR 3647 and among the beta-lactams imipenem were the most active agents tested. Anaerobic cocci (50 strains) had the following minimum inhibitory concentrations (MICs): HMR 3647, range 0.016-0.125 mg/l; imipenem, range 0.016-0.064 mg/l. Propionibacterium acnes (30 strains): HMR 3647, 0.016-1.0 mg/l; imipenem, 0.032-0.064 mg/l. Clostridium perfringens (30 strains): HMR 3647, 0.125 mg/l; imipenem, 0.016-0.5 mg/l. Clostridium difficile (50 strains): HMR 3647, 0.125-256 mg/l; imipenem, 4.0-8.0 mg/l. Bacteroides fragilis (102 strains): HMR 3647, 0.032-16 mg/l; imipenem, 0.064-0.25 mg/l. Bacteroides and Prevotella species (50 strains): HMR 3647, 0.016-4.0 mg/l; imipenem, 0.016-0.25 mg/l. Fusobacterium nucleatum (30 strains): HMR 3647, 0.016-8.0 mg/l; imipenem, 0.008-0.064 mg/l. HMR 3647 may be useful as treatment and prophylaxis for infections due to anaerobic bacteria.

Binding of mutagenic heterocyclic amines by intestinal and lactic acid bacteria.

Lactic acid bacteria have been reported to have antimutagenic/anticarcinogenic properties in vitro and in vivo. One possible mechanism for this effect involves a physical binding of the mutagenic compounds to the bacteria. The purpose of the present investigation was to study the binding capacity of eight human intestinal or lactic acid bacterial strains for mutagenic heterocyclic amines formed during cooking of protein-rich food. Binding of the mutagens Trp-P-2, PhIP, IQ and MeIQx by the bacterial strains was analyzed by HPLC. There were only minor differences in the binding capacities of the tested strains but the mutagenic compounds were bound with markedly different efficiencies. Trp-P-2 was almost completely bound and the binding tended not to be of a reversible nature. The binding of PhIP, which reached about 50%, was important as PhIP is a major mutagen in the western diet. IQ and MeIQx were slightly less well bound. pH appeared to be of importance for the binding efficacy. Binding correlated well with the reduction in mutagenicity observed after exposure of the heterocyclic amines to the bacterial strains. The results indicate that cooked food mutagenic compounds, commonly found in the western meat-rich diet, can be bound to bacteria from the normal intestinal microflora in vitro.