Kenneth J. McGinley

Physiologic and Microbiologic Changes in Skin Related to Frequent Handwashing

Handwashing practices may be adversely influenced by the detrimental effects of handwashing on skin. A protocol was developed to assess the physiologic and microbiologic effects of frequent handwashing. Fifty-two female volunteers washed their hands 24 times per day for 5 days. Five agents were tested: water alone, non-medicated bar soap, a chlorhexidine-containing antiseptic, and two agents containing povidone-iodine (one currently available on the market and one being tested for possible marketing). Some damage to the outer membrane of skin, the stratum corneum, occurred in all groups. There were significant changes in the amount of evaporation water loss (p = .001) and in self assessments of skin condition (p = .005) from pre-to-post test for the entire group. Skin damage was also assessed by visualizing desquamating stratum corneum cells, which are shed in large aggregates when detergents injure skin. Significantly less such shedding occurred in subjects using water alone, bar soap, and the chlorhexidine formulation (p = .02). Greater antimicrobial activity of an agent was not correlated with increased skin trauma. We have quantitated, using objective physiologic parameter, the skin damage that occurs during even a short period of frequent handwashing. We recommend that further studies using the methods described be conducted to quantitate skin damage over longer periods of time, more closely resembling handwashing practices of health care personnel.

Physiologic, microbiologic, and seasonal effects of handwashing on the skin of health care personnel.

The handwashing practices of 22 personnel on an oncology unit in an urban medical center were studied for 2 months. During 891 person-hours of observation, 986 handwashes were observed. Subjects washed a mean of 1.1 times an hour for a mean of 13.2 seconds. Reported and observed handwashing behavior was only moderately correlated (p = 0.05 for frequency, 0.30 for duration of handwashing). Physicians washed significantly less often (p less than 0.001), but more thoroughly (p less than 0.001), than did nurses. Nurses washed more often after minimal or no patient contact than did physicians (p less than 0.001). Individuals were very consistent in their handwashing technique. A total of 558 isolates were recovered from 158 hand cultures. The mean log count was 4.88, with no significant difference between physicians and nurses. Coagulase-negative staphylococci isolated from hands of physicians and nurses were significantly more resistant to antimicrobial agents than those of personnel with minimal patient contact (p less than 0.01). Subjects had more skin damage in winter than in summer, as indicated by increased shedding of skin squames (p less than 0.05). We conclude that handwashing practices vary significantly by profession and that reporting of handwashing practices by personnel is inaccurate.

An investigation of human apocrine gland secretion for axillary odor precursors.

Recently completed studies from our laboratories have demonstrated that the characteristic human male axillary odors consist of C6 to C11 normal, branched, and unsaturated aliphatic acids, with (E)-3-methyl-2-hexenoic acid being the most abundant. To investigate the mechanism by which the odor is formed, it is necessary to determine the nature of the odorless precursor(s) found in the apocrine secretion which is converted by the cutaneous microorganisms to the characteristic axillary odor. Pooled apocrine secretion was obtained from several male volunteers by intracutaneous injection of epinephrine. Partitioning this secretion into aqueous and organic soluble fractions was followed by hydrolysis of each fraction with NaOH or incubation with axillary microorganisms (cutaneous lipophilic corynebacterium). Analysis by gas chromatography/mass spectrometry (GC/MS) revealed the presence of (E)- and (Z)-3-methyl-2-hexenoic acid in the aqueous phase hydrolysate and aqueous phase incubated with bacteria; however, only a trace amount was seen in the resultant organic phase mixtures. These results suggest that a water-soluble precursor(s) is converted by the axillary flora to the characteristic axillary odors.

Propionibacterium acnes Colonization in Acne and Nonacne

Propionibacterium acnes is a member of the resident bacterial flora and resides in sebaceous follicles. Age-related and body-dependent quantitative differences exist, indicating the role of sebum as an important ecological factor for P. acnes. Acne patients demonstrate marked increases in this organism which generates inflammation through a variety of mechanisms.

Antibiotic resistance patterns in coagulase-negative staphylococci after treatment with topical erythromycin, benzoyl peroxide, and combination therapy

Summary Antibiotic resistance of the resident cutaneous bacterial flora is a well recognized consequence of systemic antibiotic therapy. In this study, we followed the development of antibiotic resistance of coagulase‐negative staphylococci (CNS), the most numerous aerobic bacteria found on the skin surface, during treatment with three topical antimicrobial agents used to treat acne vulgaris. Groups of 20 subjects received either topical erythromycin, benzoyl peroxide or a combination of the two for 16 weeks. After 12 weeks of treatment with erythromycin, the aerobic flora was dominated by S. epidermidis which was completely resistant to erythromycin. In addition there was an increase in resistance to clindamycin and tetracycline. Treatment with benzoyl peroxide and the combination of erythromycin and benzoyl peroxide resulted in a significant reduction in the number of aerobic bacteria without any change in the resistance pattern to erythromycin or other antibiotics.

Facial follicular porphyrin fluorescence: correlation with age and density of Propionibacterium acnes

The incidence and distribution of facial follicular porphyrin fluorescence was studied in a large group of subjects ranging in age from 1 to 90 years. Fluorescence appears first on the nose and chin, increases in incidence through adulthood and declines after the age of 50 possibly reflecting the rate of sebum secretion. We have shown that the intensity of fluorescence is proportional to the P. acnes population and confirmed that coproporphyrin III is produced in vivo.

Pitted keratolysis: the role of Micrococcus sedentarius

Though pitted keratolysis of the foot is generally viewed to be caused by bacteria, there is confusion regarding the identity of the causative organism. Species of Corynebacterium, Actinomyces, Dermatophilus, and Micrococcus have been proposed by various investigators. We have studied eight cases of pitted keratolysis and have cultured an organism identified as Micrococcus sedentarius on the basis of colonial morphology, micromorphology, biochemical reactions, and chemical analysis of whole-cell components. Furthermore, pitted keratolysis was produced experimentally in a human volunteer by applying M sedentarius under an occlusive dressing onto the surface of the heel.

Handwashing practices and resistance and density of bacterial hand flora on two pediatric units in Lima, Peru*

The handwashing practices and bacterial hand flora of 62 pediatric staff members of a teaching hospital in Lima, Peru, were studied. Handwashing followed patient contact 29.3% of the time (204/697 contacts). Mean duration was 14.5 seconds, and significant differences in practices were found by unit (rehydration or neonatal intensive care), type of staff member (nurses or physicians), and type and duration of patient contact. Mean count of colony-forming units was log10 5.87 +/- 0.41, with significant differences in density of flora found between patient care and kitchen staffs. There was no significant effect of handwashing on counts of colony-forming units. Significant differences were also found by unit and by staff position with regard to species isolated and antimicrobial resistance of isolates. A more efficacious and cost-effective form of hand hygiene and a more prudent use of antimicrobial agents are indicated.

Effect of 13-cis-retinoic acid on sebum production and Propionibacterium acnes in severe nodulocystic acne.

SummaryTen patients treated with 13-cis-retinoic acid demonstrated a 70% reduction in sebum excretion on the forehead and cheek. An average reduction of 66% occurred in the 1st month, slowly increased to 70% by the 3rd month, and then remained constant for the final 2 months of therapy. Concomitant with this sebum excretion reduction was a fall in the number of Propionibacterium acnes recovered from both sites. Pretreatment values of 104P. acnes per square centimeter (cm2) fell to 103 per cm2 after 1 month and 102 after 9 months of therapy. P. acnes was not recovered from six of the ten subjects in the following 3 months and only at levels of 102 per cm2 in three subjects. One subjects P. acnes level was reduced to only 104 per cm2. Following discontinuation of therapy, sebum levels and P. acnes counts showed a trend to recover to pretreatment levels within 2 months.ZusammenfassungZehn Patienten, die mit 13-cis-Retinsäure behandelt wurden, zeigten eine Reduktion der Talgsekretion um 70% an Stirn und Wangen. Während des ersten Behandlungsmonats zeigte sich eine durchschnittliche Reduktion um 66%, die sich langsam im dritten Monat auf 70% steigerte und dann über die letzten beiden Behandlungsmonate konstant blieb. Im Zusammenhang mit dieser Verringerung der Talgsekretion zeigte sich an beiden untersuchten Arealen ein Rückgang von Propionibacterium (P.) acnes. Die Ausgangswerte von 104P. acnes pro Quadratzentimeter Hautoberfläche fielen nach 1 Monat auf 103 und nach 2 Monaten auf 102 pro Quadratzentimeter. Während der folgenden 3 Monate konnte P. acnes an sechs von zehn Patienten nicht mehr nachgewiesen werden, und bei drei Probanden fanden sich nur noch Bakterienzahlen von 102 pro Quadratzentimeter. Ein Patient wies nur eine Reduktion auf 104 Bakterien pro Quadratzentimenter auf. Nach Beendigung der Therapie zeigten Talgsekretionsrate und Anzahl der P. acnes innerhalb von 2 Monaten eine Annäherung an die Ausgangswerte.

Inhibition of lipase production in Propionibacterium acnes by sub‐minimal‐inhibitory concentrations of tetracycline and erythromycin

Tetracycline, declomycin and erythromycin, in concentrations lower than the minimal inhibitory dosages, were shown to inhibit lipase production by Propionibacterium acnes in vitro.