Effects of systemic demethylchlortetracycline on human cutaneous microflora

Systemic therapy for acne vulgaris

There are three main groups of systemic therapies available for the treatment of acne vulgaris: systemic antibiotics, hormonal therapy (for females) and oral isotretinoin. This article outlines when these treatments should be prescribed for the treatment of acne, considers the impact of therapy on aetiology, and advises on dosage regimens, potential adverse effects and expected efficacy.

Synthesis and antibacterial evaluation of novel water-soluble organic peroxides

A set of new water-soluble organic peroxides has been synthesized and evaluated for in vitro antibacterial activity as part of an effort to develop new antibacterial agents for the treatment of acne vulgaris. The water solubility of these new dialkyl peroxides and peroxyesters was achieved by incorporating either a quaternary ammonium group or a polyethylene glycol moiety. These peroxides are effective against both gram-positive and gram-negative bacteria and have a prolonged activity compared to that of benzoyl peroxide and other peroxide-type antiseptic agents. Among them 4-[[(tert-butylperoxy)carbonyl]benzyl]triethylammonium chloride and [10-(tert-butylperoxy)decyl]trimethylammonium bromide have the broadest antimicrobial spectrums. We have shown that the oxidizing properties of the dioxy group of these compounds are responsible for their antibacterial activities.

Handwashing and skin. Physiologic and bacteriologic aspects

Handwashing practices are often based on tradition and belief. To develop sound rationale for handwashing practices, the physiologic and bacteriologic effects of handwashing must be examined. The purposes of this article are to review the three major microenvironments of the skin with their bacterial flora, to discuss physiologic and bacteriologic characteristics of the skin with particular reference to handwashing, and to describe current handwashing recommendations and practices.

Sex, constancy, and skin bacteria

Quantitative studies of the aerobic flora of seven skin sites in 16 volunteers were repeated after 3 months. The total aerobic densities of the sites differed, male carried more organisms than females and also more biotypes. Qualitative differences in the flora could be detected.

Effect of antimicrobial soap containing chlorhexidine on the microbial flora of skin

The qualitative and semiquantitative changes in the aerobic microbial flora of normal skin with the prolonged use of a chlorhexidine scrub (6 months) were investigated. More samples in the chlorhexidine scrub group had gram-negative bacilli in their axilla (63 of 96, 66%) and groin (36 of 96, 38%) than the controls (32 of 66, 49%, for axilla and 7 of 66, 11%, for groin; P = 0.01). Klebsiella and Enterobacter were the predominant organisms in the control and chlorhexidine groups, respectively. The chlorhexidine scrub produced a reduction in the total aerobic counts in the axilla, groin, and between the toes and the fingers. Fewer samples from the chlorhexidine-treated areas revealed the presence of lipophilic diphtheroids than did the controls. Lipophilic diphteroids were also reduced quantitatively in the groin and axilla with chlorhexidine treatment. No consistent pattern for the other major groups of bacteria was noted between the treatments.

Effects of an antibacterial soap on the ecology of aerobic bacterial flora of human skin

The effects of ad lib use of an antibacterial soap containing 1.0% trichlorocarbanilide and 0.5% trifluoromethyldichlorocarbanilide on the bacterial flora of six skin sites of 132 subjects were measured by comparison with the flora of 93 control subjects who avoided the use of topical antibacterials. Each subject was examined once. The test soap produced significant reductions in geometric mean counts of the total aerobic flora on the back, chest, forearm, calf, and foot; counts were also reduced in the axilla, but not to a significant extent. The overall reduction by the test soap on all sites was 62% (P less than 0.001). Neither age nor sex influenced the effect of the soap on the flora. The antibacterial soap also reduced the prevalence of Staphylococcus aureus on the skin, mostly by virtually eliminating it from areas other than the axilla. Partial inhibition of the gram-positive flora was not accompanied by an increase in gram-negative species. The latter were found principally in the axilla; Klebsiella pneumoniae and Enterobacter aerogenes were the species most frequently found.

Effects of a systemic antibiotic on nasal bacterial ecology in man

The nasal flora of coagulase-positive staphylococcus carriers and noncarriers was studied in aerobic conditions in 17 individuals. Five hundred milligrams of cephalexin was given orally four times daily for 12 days, and its effects on the nasal bacteria were determined quantitatively before, during, and after treatment. The total count obtained before the drug treatment was 5.4 x 10(6) in carriers and 3.9 x 10(6) in noncarriers. The lowest total count observed was 3 days after the cessation of the drug. The increase in gram-negative rods was seen 9 days after antibiotic therapy, not during the greatest reduction of gram-positive bacteria. Coagulase-positive cocci and diphtheroids were most sensitive to drug treatment. After 36 days, the total count was restored to pretreatment level. Diphtheroids did not return to the original number and were replaced by a corresponding increase of resistant coagulase-negative cocci. An inverse relationship between coagulase-negative cocci and lipophilic diphtheroids was seen in the anterior nares of many individuals. No gross difference in nasal ecology to differentiate carriers from noncarriers was seen.

Comparative enumeration of lipophilic and nonlipophilic cutaneous diphtheroids and cocci

Swabbing skin to collect bacteria for enumeration revealed that a single washing or rinsing of the swab in buffer removed between 90 and 95% of the bacteria collected. Further removal of the remaining bacteria from the initial swab by repeated washings of the swab produced plate counts that showed nearly proportional decreases in the numbers and types of bacteria retained or eluted from the swab. None of the commonly isolated cutaneous bacteria was retained or eluted from the single swab in numbers that misrepresented measurement of their proportions present in the sample. Populations of nonlipophilic bacteria on skin when present were mainly gram-positive catalase-producing cocci. Diphtheroids when present were chiefly lipophilic. Media containing furoxone were selective for cutaneous diphtheroids. The concentration of furoxone used affected isolation and enumeration of the diphtheroids. Lipophilic diphtheroids from the stratum corneum were basically aerobic and anaerobic incubation reduced or eliminated this group from enumeration studies. Lipophilic furoxone-resistant aerobic diphtheroids from several areas, particularly the nasal passages, occurred in numbers inversely proportional to the numbers of staphylococci for periods up to 11 months. The cocci-diphtheroid relationships occurred independently of the total number of aerobic bacteria present, the transient appearance of yeasts or gram-negative bacilli, the required use of certain antibiotics by the subjects, climate, age, and sex.