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Publications and source records attributed to K J McGinley.
Propionibacterium acnes is a number 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.
Previously, we described methods for measuring in vivo antimicrobial activity in which the resident bacterial flora of the forearm is expanded by occlusion with an impermeable plastic film, test agents are applied and quantitative cultures are obtained at varying time points. This methodology allows for an in vivo quantitative assessment of antimicrobial effects directed against a dense flora comprised primarily of staphylococci. This method may not be applicable to situations in which there is a high density of multiple species of bacteria. We describe herein new methods which permit in vivo determination of antimicrobial activity against a dense, mixed flora. Swabs moistened with a dilute nonionic detergent are used to remove bacteria from the subject's axilla or groin which are then translocated to the subject's forearm. Occlusion of the forearm with a large, sterile plastic chamber provides the necessary humid environment to yield a dense flora (10(5)-10(6) CFU) consisting of gram-positive cocci, gram-positive coryneforms and gram-negative rods. In this manner, multiple test sites are created on each forearm allowing for the simultaneous evaluation of multiple antimicrobial agents in a single subject. This method allows for the evaluation of the immediate, as well as sustained, in vivo bactericidal effect of an antimicrobial agent against a dense mixed flora with quantitative cultures obtained at varying time points after application of the test agent. Furthermore, ecological pressures which select for resistant organisms or allow for an overgrowth of nonsensitive bacteria can be evaluated by determining the composition of the flora after single or repeated applications of a test agent. The testing methodologies described herein can provide relevant information regarding the antimicrobial effectiveness of an agent in a variety of situations such as use against the axillary flora (including its utility as a deodorant), use as a perineal cleanser for critically ill, hospitalized patients and use in situations where a dense mixed flora exists, e.g. stasis ulcers and infected intertriginous dermatoses.
BACKGROUND: Previous studies have indicated that cutaneous bacteria, particularly coagulase-negative staphylococci, play a role in the pathogenesis of miliaria. An accumulation of periodic acid-Schiff (PAS)-positive material has been described as blocking the sweat duct in miliaria. Furthermore, a PAS-positive extracellular polysaccharide substance (EPS) has been identified as a product of some strains of Staphylococcus epidermidis. OBJECTIVE: We evaluated the relative ability of various species of coagulase-negative staphylococci to induce miliaria with particular reference to the potential role of EPS. METHODS: We inoculated various strains of coagulase-negative staphylococci on the volar forearms of subjects under an occlusive dressing coupled with thermal stimulation. Ability to induce miliaria as well as microbiologic, histologic, and immunostaining features were evaluated. RESULTS: Miliaria was induced only with strains of S. epidermidis; other species including S. haemolyticus, S. hominis, S. cohnii, S. saprophyticus, and S. simulans were not capable of inducing miliaria. Moreover, only S. epidermidis strains capable of producing EPS were capable of inducing miliaria. CONCLUSION: Our data indicate that EPS is the PAS-positive material that obstructs the delivery of sweat to the skin surface in miliaria and therefore demonstrate that the EPS produced by S. epidermidis plays a central role in the pathogenesis of miliaria. Furthermore, in a survey of staphylococcal flora isolated from 68 subjects, EPS-producing strains were found to be common.
OBJECTIVE: To quantify and characterize the asymptomatic carrier state of tinea capitis in school children from the inner city. METHODS: All students attending a parochial school (kindergarten through seventh grade) in the city of Philadelphia were cultured for tinea capitis periodically over 16 months (1404 hemi-scalp cultures from 224 children). RESULTS: Our initial prevalence study of this all-black population (ages 5 to 13 years) found a 3% rate of index cases (symptomatic) and a 14% rate of asymptomatic carriers (without black-dot lesions, obvious hair loss, scaling, crusts, pustules, or erythema). Trichophyton tonsurans was the predominant dermatophyte (96% of 125 positive cultures; Microsporum canis was the only other isolate). Fifty percent of all positive cultures came from children in kindergarten and first grade; first grade had the highest rate of index cases. The overall prevalence of asymptomatic carriers was not higher in the classes containing index cases. Fifty-nine percent of asymptomatic carriers had a 1+ spore load (1 to 10 colonies isolated per scalp), while 74% of index cases had a 4+ spore load (> 150 total colonies). Forty-five untreated asymptomatic carriers were followed for 2 to 5 months: 19 (42%) became culture-negative; of these, 17 (90%) had a 1+ spore load. CONCLUSIONS: We found that inner-city black school children who are asymptomatic carriers of T tonsurans had lower spore loads than index cases. Index cases did not appear to be the primary mode of transmission within a classroom. More than half of untreated asymptomatic carriers remained culture-positive after 2 months and probably play a role in the transmission of tinea capitis within this population.
We studied the effects of four kinds of antimicrobial detergents, 4% chlorhexidine gluconate (CHG), chlorbenzarconium (CBC), 10% povidone-iodine (PVI), 0.3% triclosan (TRI), and one non-medicated detergent (NMD) using the full-hand touch plates method. Before and after 3 minutes of hand scrubbing with a brush, bacterial colonies on the hand surface and subungual bacteria were counted. CHG, CBC, and PVI were excellent antimicrobial detergents against hand surface bacteria, but most of the subungual bacteria remained. The subungual space was the most difficult region from which to eradicate bacteria. TRI was much less effective than hand soap against hand surface bacteria.
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.
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.
A method is described for quantification of the bacterial flora on the hand surface. Computer-assisted image analysis of bacterial growth of large full-hand touch plates provides a quantifiable measure of the bacterial flora on the hand surface. Image analysis pixel intensity values showed a significant correlation (P less than 0.0001) with colony forming unit values determined by the glove juice method. Image analysis of impressions from hands treated with various antimicrobial agents in detergent bases showed that 4% chlorhexidine gluconate produces a 96% reduction after a 30 s washing and 98% reduction after a 3 min washing while 7.5% povidone-iodine and 1% triclosan produce a 77% and 70% reduction after 3 min respectively, and 70% isopropanol produces a 98% reduction after a 30 s wash.
The microbial flora of 60 vase water samples from cut flowers obtained from several environments, including a hospital, were examined in this study. Forty-one different bacterial species were identified, including 12 species of Pseudomonas. The mean total aerobic bacterial count per 500 ml of vase water was 4.5 x 10(8) organisms, and high levels of antibiotic resistance were found. To ascertain the origin of the bacteria found on the flowers as well as their growth patterns, natural cut flowers were compared with sterilized cut flowers in tap water over time. Although the density of organisms was similar, the flora in vase water of sterilized flowers consisted almost entirely of aerobic spore formers while mixed flora of gram-negative bacteria, staphylococci, aerobic spore formers, and fungi were isolated from natural flowers. Our results indicate that the multiply-resistant microbial flora found in vase water is indigenous to flowers, rather than originating from the environment in which they are placed, and that such water is a reservoir of large numbers of multiresistant organisms.
Fungal foot infections are becoming an increasingly common public health problem as the population ages. New studies have shown that some of the traditional therapeutic antifungal agents have multiple actions that enable them to be more efficacious than previously thought, and more efficacious than other agents without multiple actions. In this review article, the pedal infections commonly referred to as tinea pedis, or athlete's foot, are described. The etiologic agents involved in the pathogenesis, the methodologies for proper diagnosis, and the therapeutic agents commercially available for treatment are reviewed.
The microbial flora of normal and macerated interdigital toe web spaces was qualitatively and quantitatively identified in 77 patients. Dermatophyte fungi were recovered from 11% of normal patients compared with a 31% recovery from patients with macerated interspaces. Macerated interspaces were characterized by a greater recovery of organisms with pathogenic potential, with Staphylococcus aureus recovered from 36% of patients, Micrococcus sedentarius in 37%, Brevibacterium epidermidis in 54%, Corynebacterium minutissimum in 69%, and Pseudomonas species in 26%. The bacterial flora of macerated interspaces showed a significantly higher incidence of resistance to multiple antibiotics, and the recovery of antibiotic-resistant bacteria correlated with the recovery of dermatophytes that produce penicillin-like substances. The results of this study support the hypothesis that overgrowth of the resident bacterial population determines the severity of interdigital toe-web infections.
Twenty-four patients with severe interdigital toe web infections and no evidence of dermatophyte colonization received randomized treatment with either econazole nitrate (Spectazole) or its vehicle. Of the patients treated with econazole nitrate, 88% had good to excellent responses, whereas no patient treated with the vehicle showed improvement. The total aerobic flora in the econazole group decreased 93%, with decreases in the large-colony diphtheroids, lipophilic diphtheroids, and gram-negative bacteria. The results of this study demonstrate that the antibacterial activity of econazole nitrate makes it an effective agent for the treatment of severe interdigital bacterial infections uncomplicated by dermatophyte colonization.
Quantitative cutaneous bacteriological profile analysis was performed on 20 healthy Japanese adults. Five ecologically different sites were cultured, the forehead, anterior nares, axilla, perineum, and fourth interspace. Antibiotic sensitivity patterns were determined for the various species of coagulase negative cocci (CNS). Aerobic organisms were found in densities exceeding 10(6) per sample for all sites except the forehead (10(4)), while anaerobic Propionibacteria were found in quantities ranging from 10(5) to 10(6) per sample except for the toe web space, which was devoid of anaerobic organisms. CNS were ubiquitous. Staphylococcus aureus varied from 15% to 35%. Lipophilic diphtheroids were found in 50% of the subjects on the forehead and nearly 100% on other sites, whereas multiple antibiotic resistant lipophilic diphtheroids (Group JK) were found in the perineum of 35% and in the toe space of 15%. Gram negative bacilli were uncommon on the forehead, axilla, and the toe web space, but were found in 50% or more in the anterior nares and perineum. Penicillin and ampicillin resistant CNS were commonly seen, while oxacillin and cephalosporin resistance were uncommon. Tetracycline and erythromycin resistance was seen in 35% to 40%.
Methodologies for evaluating the efficacy of antimicrobial agents in the bacterial flora of the hand involve variations of the "glove juice" or "sterile bag" procedures. In this study we demonstrate that the subungual flora contribute significantly to the recovery of bacteria in these procedures. Culturing hands that had the subungual spaces sealed with acrylic polish demonstrated a decay type of curve for the number of bacteria recovered in successive samplings with 10(6) colony forming units (CFU) bacteria recovered in the first sampling and 10(3) in the sixth while the opposite hand on which the subungual spaces were not sealed demonstrated a continuous recovery of 10(6) CFU. Serial scrubbings of three minutes with plain detergent, 10% povidone-iodine or 4% chlorhexidine demonstrated a three logarithm reduction for povidone-iodine and four logarithm reduction compared to plain detergent alone for chlorhexidine in hands that had subungual spaces sealed, while the opposite hand showed only a 0.5 to 1.0 logarithm reduction. Povidone-iodine produced a 0.6 logarithm reduction and 4% chlorhexidine or 1.4 logarithm reduction in the density of subungual bacteria.
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In many parts of the world, the emergence of multiple antibiotic resistant Group JK has been recognized as an important cause of nosocomial infection in immunosuppressed and neutropenic patients. Group JK infections have not been reported from Japan. We studied 20 Japanese who had recently come to the United States and recovered Group JK from 7 of 20. These results suggest that Group JK may be prevalent in Japanese. Previous failure to identify these organisms may reflect their poor growth on agar not supplemented with lipid and their resemblance to bacteria considered to be commensals and non-pathogenic.
The normal microflora of skin vary significantly between sebaceous rich, wet, and dry areas. This would be expected to influence the likelihood of developing transient bacteremia while undergoing skin surgery on these different areas, thereby affecting the risk of infective endocarditis from such procedures. We evaluated the incidence of transient bacteremia in 45 patients undergoing skin surgery on the sebaceous rich areas of the head and neck. After surveillance skin cultures, aerobic and anaerobic blood culture samples were taken at 0, 1, 5, and 15 minutes after the start of the procedure. All baseline blood culture results were negative. Three of the 45 patients developed transient bacteremia within the first 15 minutes after the start of the procedures. Samples from two patients grew pure cultures of Propionibacterium acnes and that from one patient grew a pure culture of Staphylococcus hominis, yielding a 7% incidence of bacteremia in the 45 patients studied. These data support the use of perioperative prophylactic antibiotics for surgery involving clinically uninfected skin of the head and neck only in patients with prosthetic heart valves. This is in keeping with the current recommendations of the American Heart Association against the need for antibiotic prophylaxis for nonprosthetic valve endocarditis in patients undergoing cutaneous surgery on clinically uninfected skin.
Multiple skin sites and the gastrointestinal tract of 57 infants with otitis media were cultured quantitatively for Candida albicans before and after antibiotic therapy. Ten days of systemic therapy with amoxicillin was associated with a twofold increase in the recovery of C. albicans from the rectum and skin. Infants who developed diaper dermatitis had a significant increase in the number of C. albicans organisms recovered from these sites. We conclude that the use of amoxicillin increases the risk for developing diaper dermatitis.