Prevalence of methicillin-resistant Staphylococcus aureus in a dermatology outpatient population.

BACKGROUND: The number of methicillin-resistant STaphylococcus aureus (MRSA) infections in the hospital setting is increasing but little is known of its prevalence in the community. In a 1986-1987 study, the prevalence in dermatology outpatient clinics was <0.9%. This study reports changes in the same facilities from 1988 through 1996. METHODS: Culture results and antimicrobial susceptibility patterns were reviewed for the population for the period 1988 through 1996. RESULTS: We report a gradual increase of MRSA from 1.5% of all strains of Staphylococcus aureus in 1988 to 11.9% in 1996 in these outpatient facilities. Susceptibility data indicate that the MRSA strains isolated in 1996 are more resistant to oral agents such as ciprofloxacin and tetracycline, while all strains remain susceptible to the intravenous agent vancomycin. CONCLUSION: The prevalence of MRSA in the community is increasing and should be considered when selecting a treatment regimen for staphylococcal infections.

Chopart prosthesis and semirigid foot orthosis in traumatic forefoot amputation. Comparative gait analysis.

Gait was analyzed in seven otherwise healthy males at least 11 mo after they had recovered from a traumatic unilateral transmetatarsal amputation incurred during the course of their usual occupation. All seven were fitted with a semirigid foot orthosis. Four were also fitted with a Chopart prosthesis. Gait was evaluated with forceplate measurements of ground reaction force during free walking, by clinical observation of such ambulation on videotape, and by the subjective impression of the men as obtained by a questionnaire. In all men, with unmodified footwear, with the orthosis, and with the prosthesis, the forceplate data showed an abnormal pattern characterized by reduced stance duration and deficient forward propulsion on the amputated side. The abnormality and asymmetry of ground-reaction forces were less with greater preserved stump length and for a given stump length were with the above-ankle concept (Chopart) prosthesis than with the below-ankle concept. These features were recognized during the clinical analysis of all footwear, but there was an extra irregularity of weight progression noted with the fixed ankle of the Chopart prosthesis. The questionnaire reported stump problems to be the principal difficulty, and the follow-up revealed persistent attempts at surgical management including consideration of amputation at a higher level. It was concluded that the patient and the surgeons are likely to choose preservation of limb length over considerations of function during acute care and that the prosthetic concept best suited to deal with the resulting stump should emphasize unloading the distal part of the stump and smoothing out the impulsive force peak on the stump in late stance to minimize pain and to enhance ambulation capacity.

A polygenic mouse model of psoriasiform skin disease in CD18-deficient mice.

Previously, a hypomorphic mutation in CD18 was generated by gene targeting, with homozygous mice displaying increased circulating neutrophil counts, defects in the response to chemically induced peritonitis, and delays in transplantation rejection. When this mutation was backcrossed onto the PL/J inbred strain, virtually all homozygous mice developed a chronic inflammatory skin disease with a mean age of onset of 11 weeks after birth. The disease was characterized by erythema, hair loss, and the development of scales and crusts. The histopathology revealed hyperplasia of the epidermis, subcorneal microabscesses, orthohyperkeratosis, parakeratosis, and lymphocyte exocytosis, which are features in common with human psoriasis and other hyperproliferative inflammatory skin disorders. Repetitive cultures failed to demonstrate bacterial or fungal organisms potentially involved in the pathogenesis of this disease, and the dermatitis resolved rapidly after subcutaneous administration of dexamethasone. Homozygous mutant mice on a (PL/J x C57BL/6J)F1 background did not develop the disease and backcross experiments suggest that a small number of genes (perhaps as few as one), in addition to CD18, determine susceptibility to the disorder. This phenotype provides a model for inflammatory skin disorders, may have general relevance to polygenic human inflammatory diseases, and should help to identify genes that interact with the beta2 integrins in inflammatory processes.

The effect of 610 m altitude on rowing ergometer performance.

Anecdotal evidence suggests that the 610 m altitude of the Australian Institute of Sport in Canberra may affect athletic performances, despite the lack of theoretical evidence to support this. Also, the lower air resistance at altitude could alter the mechanics of air-braked exercise ergometers. Therefore, this study compared performance on a Concept II Rowing Ergometer at sea level (SL) and at Canberra (CB). Fourteen male junior rowers (age 16.1 +/- 0.6 years, weight 73.4 + or - 4.1 kg height 182.7 + or - 43 cm) completed two six-minute all-out rowing ergometer tests, in random order at either SL or CB. There was a significantly different (p < 0.001) peak VO2, 4.12 + or - 0.24 (SL) and 3.97 + or - 0.25 l-min-1 (CB). However there was only a small but non-significant difference in the distance completed; 1672 + 39 m (SL) to 1666 + or - 44 m (CB). The similar work completed at CB despite a lowered peak VO2 could not be explained by an increased energy contribution by glycolysis or by changes in rowing efficiency. Peak VI ATP was similar at both locations, although when corrected to STPD was significantly different (p < 0.001). Mean FEO2 was 17.29 + or - 0.25 (SL) and 17.09 + or - 0.28 (CB) indicating a greater O2 extraction at CB, which partially compensated for the lower PIO2. This effect on VO2 at such a low altitude has not been shown before, and means that altitude should always be considered in the interpretation of the results of aerobic fitness tests.

A new Brevibacterium sp. isolated from infected genital hair of patients with white piedra.

A new aerobic gram-positive non-sporeforming bacillus has been isolated from infected genital hair of patients with white piedra in association with Trichosporon beigelii. This species has been characterised morphologically, nutritionally, by DNA base composition, cell-wall analysis and cellular fatty-acid profile on the basis of 14 isolates. The G+C content of DNA is 63.05 mol%. Cell walls possess meso-diaminopimelic acid (Type IV) and the sugars glucose, galactose, xylose and ribose; mycolic acids are not present. The species has a distinct colonial and microscopic morphology, is strongly proteolytic and produces methanethiol. These findings and the cellular fatty-acid profile are compatible with the genus Brevibacterium. A new species is proposed based on the following characters: colonial and microscopic growth and morphology; conditions for rod-to-coccus cycle; ribose utilisation; and tellurite reduction. The type strain has been named Brevibacterium mcbrellneri E2cr (ATCC 49030). The strong proteolytic properties may be the mechanism of pathogenesis.

Evaluation of commercial blood-containing media for cultivation of Mycobacterium haemophilum.

Mycobacterium haemophilum requires hemin for growth, and thus it is unlikely to be isolated by current routine methods. This study evaluated growth of M. haemophilum on commercially available blood agar and on different basal media and with other sources of hemin. The effect of dyes, crystal violet and malachite green, in controlling contamination was tested. Results showed that although M. haemophilum can grow on a variety of commercially prepared blood agars, contamination is a significant deterrent. Both malachite green and crystal violet inhibited the growth of contaminants without affecting the growth of M. haemophilum. The following medium (MMV: McBride's Mycobacterium Haemophilum) is recommended: Casman's blood agar base containing 5% sheep blood heated and 5 micrograms/mL crystal violet, prepared in screw-topped vials, tightly capped and incubated at 30 degrees C under atmospheric conditions.

Comparative biomechanical analysis of energy-storing prosthetic feet.

Gait analysis was performed on eight men who had unilateral traumatic below-knee amputation and on nine control subjects. Each subject was given two prostheses--the Seattle Foot and the Flex Foot--which differed only in the energy-storing foot component. Analysis of subjects consisted of clinical gait observation, forceplate analysis of the ground reaction force (GRF) while using each prosthesis during level walking at the natural cadence, and evaluation of subject preference between the two prosthetic feet. In the control subjects, there was no significant asymmetry in any averaged GRF patterns or parameters. In the subjects with amputations, the amputated limb had a weaker propulsion and the nonamputated limb had a stronger propulsion than controls. This was true for both prostheses. During ambulation with the Flex Foot, there was a pattern of larger late vertical forces but smaller late anteroposterior and mediolateral forces. This is consistent with a medial heel whip, and it was observed when the Flex Foot was used. Three months after the biomechanical studies, four subjects used the Flex Foot exclusively, two used the Seattle Foot exclusively, and two used both, ie, the Flex Foot for sports and the Seattle Foot for work. Application of these results to the choice of prosthetic components is discussed.

Evidence for percutaneous inoculation as the mode of transmission for chromoblastomycosis.

The exact pathogenesis of chromoblastomycosis is unknown. Direct percutaneous inoculation, inhalation, and hematogenous dissemination have been implicated. We report a case of chromoblastomycosis that followed a well-defined episode of penetrating trauma. The causative organism, Fonsecaea pedrosi, was cultured from the patient's lesion and from the tree branch responsible for the trauma. This "natural" experiment supports the contention that one cause of chromoblastomycosis is traumatic cutaneous implantation of the fungus.

Naftifine treatment of trichomycosis pubis.

Naftifine hydrochloride 1% cream is a recently developed material of proven efficacy in superficial cutaneous fungal infections. The drug has also been reported to have significant antibacterial properties as well. A case of trichomycosis pubis, a bacterial disorder that can easily be mistaken for several fungal diseases, responded to application of naftifine cream. The authors suggest that this medication may be the drug of choice when the clinical presentation consists of nodules encircling pubic or axillary hair.

Prevalence of Trichosporon beigelii. Colonization of normal perigenital skin.

Although the natural habitat of Trichosporon species is considered to be the soil, the role of normal skin in the carriage of Trichosporon beigelii is unknown. The purpose of this study was to determine the prevalence of T. beigelii colonization on normal perigenital skin. Inguinal skin scrapings were obtained from 322 asymptomatic volunteers. There were 261 males and 61 females ranging in age from 18 to 89; 136 were white, 134 were black, and 52 were Hispanic. Specimens were cultured on Sabouraud's glucose agar containing 500 micrograms ml-1 chloramphenicol, and incubated at 23-26 degrees C for up to 4 weeks. The overall incidence of T. beigelii colonization was 12.4%. However, this varied with patient's age, sex, race and socioeconomic background. The highest prevalence (27.1%) was found in black males who attended a Veterans Affairs hospital. The prevalence was lowest in females (1.6%), and no patients who attended a private clinic were colonized. It was concluded that T. beigelii colonizes normal skin with some regularity.

White piedra: evidence for a synergistic infection.

To determine the relative roles of coryneform bacteria and Trichosporon beigelii in the pathogenesis of genital white piedra, scrotal hair from 10 subjects was studied. Hairs were examined by light microscopy to determine the relative proportions of each organism, and were also cultured for coryneforms and yeast. Histologically, hair nodules from five out of nine cases showed a mixture of yeasts and bacteria, four had bacteria alone, and none showed yeast alone. Five strains of T. beigelii were cultured, two strains of Saccharomyces cerevisiae and 22 strains of coryneforms. The isolates were tested for synergism by a plate-overlay method. Growth of coryneforms occurred over and around sections of the plate inoculated with T. beigelii but not around the control yeast, S. cerevisiae. There were strain differences in the stimulatory response of both T. beigelii and coryneform strains. In reverse experiments coryneforms did not enhance growth of T. beigelii. It was concluded that white piedra is a mixed infection caused by the synergistic action between T. beigelii and a specific coryneform bacteria resulting in invasion of the hair cuticle and cortex.

Evaluation of antibacterial sensitivity testing methods for methicillin-resistant Staphylococcus aureus in a dermatology outpatient population.

Over a period of one year, 1986-1987, 116 strains of Staphylococcus aureus were isolated from patients attending two outpatient dermatology clinics in Houston, Texas. The purpose of this study was to evaluate the adequacy of routine antibiotic sensitivity testing methods for detecting methicillin-resistant Staphylococcus aureus (MRSA). The Kirby-Bauer disk diffusion method was compared with a commercially available screening medium containing 6 micrograms/ml of oxacillin and 4% NaCl. The minimal inhibitory concentration (MIC) of methicillin, oxacillin, and oxacillin with 4% NaCl to S aureus using the agar dilution method was also determined. Approximately 90% of S aureus strains produced beta-lactamase and were resistant to penicillin and ampicillin. By disk diffusion, no strains were resistant to methicillin, though diameters of zones of inhibition were between 10 and 14 mm in seven strains. All strains proved to be sensitive to methicillin by MIC determinations and on the oxacillin-NaCl screening medium. The MIC of methicillin was 2.5 micrograms/ml for the majority of strains of S aureus, between 0.16 and 0.31 microgram/ml for oxacillin, and 0.08 to 0.16 microgram for oxacillin with 4% NaCl. We concluded that the incidence of MRSA in an outpatient dermatology population is low, and a combination of disk diffusion and oxacillin-NaCl screening is adequate for testing sensitivity.

Antifungal susceptibility testing of Trichosporon beigelii to imidazole compounds.

Twenty-two strains of Trichosporon beigelii have been tested for susceptibility to imidazole compounds. Ten strains were isolated from untreated genital white piedra lesions and 12 were from the same patients following treatment failure with imidazole compounds. Agar dilution and disk elution methods were compared using two media: yeast nitrogen base and antibiotic assay medium 3 (Difco). Antifungal agents tested were econazole, miconazole, ketoconazole, clotrimazole, and amphotericin B in concentrations of 0.0625-32 micrograms/mL. The most consistent results occurred with antibiotic assay medium 3 and the agar dilution method giving minimal inhibitory concentrations between 0.0625 and 0.25 micrograms/mL. Using yeast nitrogen base agar, minimal inhibitory concentrations were higher ranging from 0.0625 to 2.0 micrograms/mL. End points of growth in the disk elution method were not clearly delineated and ranged from 0.0625 to 8.0 micrograms/mL. The distribution of minimal inhibitory concentrations obtained using different media and methods were compared by chi 2 analysis, and the medium was found to significantly change the minimal inhibitory concentrations. There was no difference in the susceptibility of strains of T. beigelii to imidazole compounds whether isolated before or after treatment. It was concluded that in vitro susceptibility of T. beigelii to imidazole compounds did not necessarily predict efficacy in vivo.

The management of patients with back pain and idiopathic vertebral sclerosis.

Twenty-two patients with severe back pain associated with radiologic evidence of vertebral sclerosis are reported. There were 19 women and 3 men; the average age was 42 years. Duration of pain averaged 4.3 years. The characteristic radiologic findings were diffuse sclerosis of the anterior inferior portion of the vertebral body and narrowing of the adjacent disc space. There was no extension of the sclerosis beyond the vertebral body, no paravertebral mass, and no loss of vertebral height. These radiologic characteristics, in conjunction with other clinical findings, should permit a diagnosis without the need for biopsy.

Genital white piedra: epidemiology, microbiology, and therapy.

The epidemiology of genital white piedra was investigated in 166 young men with a variety of genital complaints. Trichosporon beigelii was isolated from sixty-six (40%) of the cultured scrotal hairs. Infection was more common among black patients--54% of those examined, compared to 16% of white patients and 30% of "others" (p less than 0.001). There was no relationship between infection and foreign travel. White piedra was also found in young women, but less frequently than in young men (14% vs 40%, respectively). Transmission rarely occurred from person to person. Occasionally multiple body sites were simultaneously infected. A relationship may exist between T. beigelii and Corynebacterium concurrently infecting genital hair shafts. Eradication of infection was extremely difficult, despite in vitro sensitivity to antifungal agents. Spontaneous remissions occurred, however, in some patients.

Single-dose treatment of uncomplicated gonorrhea: a comparison of cefonicid and penicillin.

Cefonicid, a parenteral semisynthetic cephalosporin, achieves high and sustained serum levels in humans. Activity against strains of Neisseria gonorrhoeae, including those that produce beta-lactamase, has been shown in vitro. The efficacy of 1.0 g of cefonicid was evaluated noncomparatively in 50 men with gonococcal urethritis; four failed to respond to treatment. Additionally, 57 men and 34 women received either 1.0 g of cefonicid or 4.8 X 10(6) units of procaine penicillin G plus 1.0 g of probenecid in a double-blind study. Among 17 men treated with penicillin, two failed to respond, and one failed among the 33 patients treated with cefonicid. Seventeen women received 1.0 g of cefonicid, and all cervical infections were cured. Among those who received cefonicid, 13 had rectal infections; and four had positive cultures at follow-up four to seven days posttreatment. Among the 17 women receiving penicillin, none failed to respond to therapy; only seven had both cervical and rectal infection. Of the 116 pretreatment and seven posttreatment isolates tested, 45 (37%) were inhibited by less than 0.0625 microgram of penicillin/ml and 121 (98%) were inhibited by less than 1.0 microgram/ml. Forty-one (33%) of the 123 isolates were inhibited by less than 0.0625 microgram of cefonicid/ml and 122 (99%) by less than 1.0 microgram of cefonicid/ml. The median MIC of cefonicid for the strains isolated from the women whose rectal infections were cured was 0.125 microgram/ml; that for the strains isolated from the women with rectal infections who failed to respond was 0.5 microgram/ml. Administration of 1.0 g of cefonicid intramuscularly is effective therapy for uncomplicated gonococcal urethritis in men.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbial flora of in-use soap products.

A comparison has been made of the in-use bacterial load of two bar soaps with and without antibacterials and two liquid soaps in five different locations over a 1-week period. Of the 25 samples taken from each soap, 92 to 96% of samples from bar soaps were culture positive as compared to 8% of those from liquid soaps. Bacterial populations ranged from 0 to 3.8 log CFU per sample for bar soaps and from 0 to 2.0 log CFU per sample for liquid soaps. The mean bacterial populations per sample were 1.96 and 2.47 log CFU for the two bar soaps, and 0.08 and 0.12 log CFU for the two liquid soaps. The difference in bacterial population between bar soaps and liquid soaps was statistically significant (P = 0.005). Staphylococcus aureus was isolated on three occasions from bar soaps but not from liquid soaps. S. aureus was isolated twice from the exterior of the plastic dispensers of liquid soap but not from the soap itself. Gram-negative bacteria were cultured only from soaps containing antibacterials. Bacterial populations on bar soaps were not high compared with bacterial populations on hands, and the flora was continually changing without evidence of a carrier state.

Quantitative disk method for storage of Neisseria gonorrhoeae.

A medium has been devised for the storage of Neisseria gonorrhoeae in the form of quantitated disks at -70 C. The medium consists of bovine serum albumin, 5%; inositol, 10%; glutamate, 5%; gelatin, 10%; and charcoal, 0.3%. Thirty-one strains of N. gonorrhoeae have been stored for 12 months and seven strains for 20 months. The organisms have maintained good viability and stability of colonial morphology. This procedure provides a means of maintaining high-density populations of freshly isolated strains of N. gonorrhoeae in quantitated form without subculture.