Staphylococcus aureus nasal colonization among dental health care workers in Northern Germany (StaphDent study).

Methicillin-resistant Staphylococcus aureus (MRSA) can colonize dental patients and students, however, studies on the prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) among dental health care workers (DHCW) including use of personal protective equipment (PPE) are scarce. We conducted an observational study (StaphDent study) to (I) determine the prevalence of MRSA and MSSA colonization in DHCW in the region of Mecklenburg Western-Pomerania, Germany, (II) resolve the S. aureus population structure to gain hints on possible transmission events between co-workers, and (III) clarify use of PPE. Nasal swabs were obtained from dentists (n = 149), dental assistants (n = 297) and other dental practice staff (n = 38). Clonal relatedness of MSSA isolates was investigated using spa typing and, in some cases, whole genome sequencing (WGS). PPE use was assessed by questionnaire. While 22.3% (108/485) of the participants were colonized with MSSA, MRSA was not detected. MSSA prevalence was not associated with size of dental practices, gender, age, or duration of employment. The identified 61 spa types grouped into 17 clonal complexes and four sequence types. Most spa types (n = 47) were identified only once. In ten dental practices one spa type occurred twice. WGS data analysis confirmed a close clonal relationship for 4/10 isolate pairs. PPE was regularly used by most dentists and assistants. To conclude, the failure to recover MRSA from DHCW reflects the low MRSA prevalence in this region. Widespread PPE use suggests adherence to routine hygiene protocols. Compared to other regional HCW MRSA rates the consequent usage of PPE seems to be protective.

Influence of Bio-sorb® Cream on Sweat Production and Efficacy of Surgical Hand Antisepsis Under Surgical Gloves.

Aim: Since the introduction of surgical gloves, one of the main challenges has been to improve donning and wearability. For the wearer, the formation of "glove juice" is problematic. To improve gliding properties for donning the gloves and absorbing sweat, in 1963 Bio-sorb® cream: sterile powder cream (Johnson & Johnson Medical, Gargrave, Skipton, United Kingdom) was introduced. Individuals subjectively reported a reduction of sweat production inside the glove, however, the actual effect on sweat accumulation and surgical hand antisepsis has not been examined. Methods: Twenty-six volunteers were used in a study designed to examine the effect of a sterile hand cream applied after surgical hand antisepsis on sweat accumulation inside surgical gloves. A woven cotton glove was worn underneath the surgical glove. Weight differences were used to determine the amount of sweat produced. The influence of Bio-sorb on the efficacy of surgical hand antisepsis was tested immediately and after 90 minutes of wear time by the sampling technique as per EN 12791 and by bacterial analysis of glove juice according to tentative final monograph 1994. Results and Discussion: The amount of sweat produced inside the glove was not reduced by the cream (1.07 ± 0.5 g versus control 1.03 ± 0.5 g; p = 0.75). Considering different skin conditions, it may be possible that some wearers might subjectively observe decreased sweat production after using Bio-sorb cream before donning surgical gloves, because sweat production did decrease in 10 of 26 test subjects. Bio-sorb cream did not affect the efficacy of surgical hand antisepsis either immediately or after 90 minutes. Conclusion: Because of possible risks of contamination of the surgical site with cornstarch from Bio-sorb cream in the case of a glove breach and the failed statistical proof of reduced sweat production, the use of Bio-sorb cream should not to be recommended.

Irritative potency of selected wound antiseptics in the hen's egg test on chorioallantoic membrane to predict their compatibility to wounds.

Antiseptics are being used for prevention of infections in acute wounds and for treatment of infections in acute and chronic wounds. However, some antiseptics' high tissue toxicity might delay the healing process. The aim of this study was to investigate the tissue toxicity of preferentially used wound antiseptics and the influence of antiphlogistic additives via the hen's egg test on the chorioallantoic membrane (HET-CAM). The HET-CAM is a semi-in-vivo method testing the tissue tolerability of wound antiseptics by evaluating the blood vessel reaction of the chorioallantoic membrane in terms of hemorrhage, vessel lysis, and coagulation. For each test day, selected test substances were applied on the membranes of two to three eggs according to the test protocol. The overall irritation was then evaluated by referring to a calculated score. Normal distribution of the resulting scores was confirmed by D'Agostino-Pearson omnibus K2 test. Significant differences between the antiseptics were calculated by Tukey's multiple comparisons test. Severe CAM reactions were observed after short-term application of octenidine based wound gel (0.05%) and chlorhexidine digluconate (0.5% solution), moderate reactions for octenidine (0.05%) in aqueous solution combined with dexpanthenol (1.34%) and allantoin (0.2%) or for hydrogen peroxide (1.5% and 0.5%) in aqueous solution, slight reactions were observed for hydrogen peroxide (1.5%) in aqueous solution in combination with sodium thiocyanate (0.698%) and for the combination of NaOCl/HOCl (each 0.004%). Polyhexanide (0.04%) in Ringer solution and polyhexanide (0.05%) in Lipofundin, the hemoglobin spray (10%), dexpanthenol, and allantoin showed no irritation. The HET-CAM qualifies as a primary screening test for tissue tolerance of wound antiseptics. Regarding local tolerability, polyhexanide and hypochlorite are superior to other antiseptics.

Specific and robust ion chromatographic determination of hypothiocyanite in saliva samples.

The enzymatic system in saliva, consisting of salivary peroxidase (SPO), hydrogen peroxide (H2O2), and thiocyanate (SCN-), produces hypothiocyanite (OSCN-) as a high effective antibacterial compound. OSCN- is of great importance for the natural non-specific antibacterial resistance in the oral cavity. However, no analytical method currently exists to selectively quantify OSCN- in saliva samples. A robust and specific analytical method for the determination of OSCN- was developed based on ion chromatography with combined UV and electrochemical detection. Calibration was achieved by calculating a derived calibration factor based on the known ratio of molar extinction coefficients of SCN- and OSCN-. Thus, the specific quantification of OSCN- in saliva samples is possible, as demonstrated here. The median value of 200 saliva samples was determined to be 0.56 mg L-1 (median), with a maximum of 3.9 mg L-1; the minimum value was below the detection limit (< 0.09 mg L-1). The recovery rate in individual saliva samples was 95 ± 8%.

Evaluation of three experimental in vitro models for the assessment of the mechanical cleansing efficacy of wound irrigation solutions.

The aim of this study was to compare different wound-rinsing solutions to determine differences in the efficiency and to evaluate three different in vitro models for wound cleansing. Different wound-rinsing solutions (physiological saline solution, ringer lactate solution for wound irrigation, water and a solution containing polihexanide and the surfactant undecylenamidopropyl-betain) were applied on standardised test models (one- and three-chamber model, flow-cell method and a biofilm model), each challenged with three different standardised wound test soils. In the one-chamber model saline showed a better effect on decontaminating proteins than the ringer lactate solution. In the flow-cell method, water performed better than physiological saline solution, whereas ringer lactate solution demonstrated the lowest cleansing effect. No obvious superiority between the two electrolyte-containing solutions was detectable in the biofilm model. Unfortunately, it was not possible to assess the protein decontamination qualities of the surfactant-containing solution because of the interference with the protein measurement. The flow-cell method was able to detect differences between different rinse solutions because it works at constant flow mechanics, imitating a wound-rinsing procedure. The three-chamber and the less-pronounced modified one-chamber method as well as the biofilm model had generated inhomogeneous results.

Microbial Load in Septic and Aseptic Procedure Rooms.

BACKGROUND: Highly effective measures to prevent surgical wound infections have been established over the last two decades. We studied whether the strict separation of septic and aseptic procedure rooms is still necessary. METHODS: In an exploratory, prospective observational study, the microbial concentration in an operating room without a room ventilating system (RVS) was analyzed during 16 septic and 14 aseptic operations with the aid of an air sampler (50 cm and 1 m from the operative field) and sedimentation plates (1 m from the operative field, and contact culture on the walls). The means and standard deviations of the microbial loads were compared with the aid of GEE models (generalized estimation equations). RESULTS: In the comparison of septic and aseptic operations, no relevant differences were found with respect to the overall microbial concentration in the room air (401.7 ± 176.3 versus 388.2 ± 178.3 CFU/m3; p = 0.692 [CFU, colony-forming units]) or sedimentation 1 m from the operative field (45.3 ± 22.0 versus 48.7 ± 18.5 CFU/m2/min; p = 0.603) and on the walls (35.7 ± 43.7 versus 29.0 ± 49.4 CFU/m2/min; p = 0.685). The only relevant differences between the microbial spectra associated with the two types of procedure were a small amount of sedimentation of Escherichia coli and Enterococcus faecalis in septic operations, and of staphylococcus aureus and pseudomonas stutzeri in aseptic operations, up to 30 minutes after the end of the procedure. CONCLUSION: These data do not suggest that septic and aseptic procedure rooms need to be separated. In interpreting the findings, one should recall that the study was not planned as an equivalence or non-inferiority study. Wherever patient safety is concerned, high-level safety concepts should only be demoted to lower levels if new and convincing evidence becomes available.

Effect of hand lotion on the effectiveness of hygienic hand antisepsis: Implications for practicing hand hygiene.

BACKGROUND: Skin protection products should be used after washing hands with soap, during breaks, after work, and during leisure time. Aside from their beneficial effects, skin care products may also interact with alcohol-based hand disinfectants by reducing their efficacy. The aim of this study was to investigate the effect of a hand lotion on the effectiveness of hygienic hand antisepsis using an alcohol-based handrub. METHODS: The effect of a protective hand lotion against an isopropyl alcohol-based handrub was investigated in 20 healthy volunteers according to the European standard test procedure EN 1500 in the following combinations: handwashing and application of hand lotion, only application of hand lotion, and no washing and no hand lotion (control), each for 5 minutes or 1 hour before hand antisepsis. The difference in microbiologic before-and-after values were expressed as log reduction factor. RESULTS: The effectiveness of hand antisepsis was not significantly affected in any of the groups using the tested hand lotion. CONCLUSIONS: Hand antisepsis may be delayed for 5 minutes after hand lotion application. Shorter time intervals might be possible but were not tested.

Association of salivary peroxidase activity and concentration with periodontal health: A validity study.

AIM: Whereas the relationship between myeloperoxidase and periodontitis has been widely examined that between salivary peroxidase and periodontitis has received little attention. We examined how periodontitis depends on both salivary peroxidase activity and concentration. MATERIALS AND METHODS: A full mouth, clinical assessment of probing depth was performed in a sample of 46 participants aged 25-54 years. To minimise bias, these data were corrected by data from the general population (Study of Health in Pomerania). Using five repeated measurements of activity and concentration over 1 day, we assessed daily biological variability and increased the reliability of salivary peroxidase measurements. RESULTS: Salivary peroxidase activity was associated with probing depth (interquartile range effect = -0.48; robust estimates of 95% confidence interval: -0.90 to -0.31; p = .0052), and its effect was not confounded by salivary peroxidase concentration. In turn, the effect of salivary peroxidase concentration was confounded by salivary peroxidase activity, and it was smaller than that of activity. CONCLUSIONS: We found an inverse association between salivary peroxidase activity and probing depth. Thus, our results imply that salivary peroxidase activity could be a protective factor against periodontitis. However, large, well-designed studies are needed to explore the causal mechanisms of this association.

Genes on rat chromosomes 3, 5, 10, and 16 are linked with facets of metabolic syndrome.

WOKW (Wistar Ottawa Karlsburg W) rats develop metabolic syndrome closely resembling human disorder. In crossing studies between disease-prone WOKW and disease-resistant DA (Dark Agouti) rats, several quantitative trait loci (QTLs) were mapped. To prove the in vivo relevance of QTLs, congenic DA.WOKW rats, briefly termed DA.3aW, DA.3bW, DA.5W, DA.10W, and DA.16W, were generated by transferring chromosomal regions of WOKW chromosomes 3, 5, 10, and 16 onto DA genetic background. Male (n=12) and female (n=12) rats of each congenic strain and their parental strain DA were characterized for adiposity index (AI), serum leptin, and serum insulin as well as serum cholesterol and serum triglycerides as single facets of metabolic syndrome at the age of 30 weeks. The data showed a significant higher AI for male and female DA.3aW and female DA.16W compared with DA. Serum leptin was significantly elevated in male and female DA.3aW, DA.10W, and DA.16W rats in comparison with DA. Rats of both sexes of DA.10W and female DA.16W showed significantly elevated serum insulin in comparison to DA. Female rats of all congenics had significantly higher serum cholesterol compared with DA, while males did not differ. Finally, triglycerides were only elevated in male DA.16W. The results demonstrate an involvement of WOKW chromosomes 3, 5, 10, and 16 in developing facets of the metabolic syndrome.