Aerobic Cocci Research Articles

Photochemotherapy of psoriasis: effects on bacteria and surface lipids in uninvolved skin.

The effect of PUVA therapy for psoriasis on the microbial flora and on levels and composition of skin surface lipid has been studied in ten patients. Samples were obtained from clinically uninvolved skin from the back and the forearm. There was no consistent significant change in the viable counts of aerobic cocci or anaerobic coryneforms during theraapy. A transient rise in Staphylococcus aureus counts was thought to be due to the use of emollients rather than no effect of PUVA. Genetic changes in the microorganisms were not sought. There was an increase in the amount of total lipid (both casual levels and replacement sums) during therapy. An increase of free fatty acids at the expense of triglycerides did not reach statistical significance. The influence of PUVA on the skin flora seems to be less in vivo than anticipated from in vitro studies.

Bacterial flora of comedones

Open comedones from thirty-eight patients with acne vulgaris on the face or back were compared for microbial flora. A total of eighty-three comedones from the face and sixty-three from the upper back were individually processed for quantitative bacterial analysis. The greatest difference between the flora of comedones at these two sites was that 44.6% of comedones from the back (compared to 9.6% from the face) harboured no aerobic cocci. The decreased prevalence of staphylococci in the lesions from the back reflects the relative absence of these organisms in isolated follicles from normal uninvolved skin of the back. The geometric mean count of anaerobes in comedones from the back was in the same range as the count found in isolated follicles in normal uninvolved skin in a previous study. This work supports the concept that the bacterial flora of comedones is an extension of the follicular flora and may be unrelated to the event of comedogenesis.

LY-127935: a novel beta-lactam antibiotic with unusual antibacterial activity

The in vitro activity of LY-127935, a new beta-lactam antibiotic, was examined by using 370 clinical bacterial strains. In comparison with several other beta-lactam agents, LY-127935 was the most inhibitory against the Enterobacteriaceae. It was remarkably active against multi-drug-resistant strains of Enterobacter spp., Serratia spp., and Pseudomonas aeruginosa. LY-127935 had four- to eightfold greater activity than did cefoxitin against Bacteroides fragilis. Production of beta-lactamase by Enterobacteriaceae did not influence the minimal inhibitory concentration of LY-127935. However, the beta-lactamase-producing strains of B. fragilis and Haemophilus influenzae had generally higher minimal inhibitory concentrations. LY-127935 was the least active agent tested against gram-positive aerobic cocci. Variations in pH, salt content, protein content, or inocula size had little influence on susceptibility to LY-127935. Although combination studies with LY-127935 and gentamicin demonstrated synergy for P. aeruginosa, the rates of killing for the combination and for gentamicin alone were similar.

Josamycin and Rosamicin: In Vitro Comparisons with Erythromycin and Clindamycin

The macrolide antibiotics josamycin and rosamicin were compared in vitro with erythromycin for activity against Staphylococcus aureus, S. epidermidis, and enterococci and with clindamycin for activity against a variety of anaerobic organisms. Rosamicin and erythromycin were similar in activity and superior to josamycin against aerobic cocci. Most isolates of S. aureus (96%), S. epidermidis (79%), and the enterococci (87%) were inhibited by 1.56 mug of either of the new macrolide compounds per ml. Clindamycin was the most active compound against the anaerobic organisms.

Aerobic and anaerobic flora in bladder urine of patients with indwelling urethral catheters

Twenty-five bladder urine specimens from 13 patients with long-standing indwelling catheters were obtained by percutaneous suprapubic needle aspiration to avoid contamination by extraneous flora and cultured aerobically and anaerobically. Twenty different species of organism were isolated from twenty-four positive specimens. The isolates were predominantly gramnegative aerobic or facultatively anaerobic bacilli, with occasional gram-positive aerobic cocci and yeasts. One patient had Clostridium perfringens and a Bifidobacterium and another had Veillonella and two species of Bifidobacterium. Both patients had four concomitant aerobic or facultative bacteria present. Anaerobic bacteria may therefore be found in the bladder urine of some patients with in-dwelling urethral catheters, but their role in the initiation and perpetuation of urinary tract infection in this setting remains unclear.

Quantification Of Bacteria In Isolated Pilosebaceous Follicles In Normal Skin

A technique for quantitating bacteria in isolated pilosebaceous follicles is described. This involves microdissection of the follicles from biopsies of skin, using the method of chemical pretreatment of skin to facilitate the separation of the epidermis and epidermal appendages from the dermis. The aerobic cocci and anaerobic diphtheroids in pilosebaceous follicles in 66 biopsies of scalp and 48 biopsies of skin of the upper back were quantitated using this technique. On the back, aerobic staphylococci were very sparse in normal follicles, indicating that their primary habitat on the skin must be on the skin surface rather than within follicles. Of 138 isolated follicles from skin of the upper back, 94 contained no aerobic cocci. Anaerobic organisms were present in high numbers within normal follicles. The geometric mean density of anaerobes in 138 isolated follicles from skin of the upper back was 3.8 X 10(4) diphtheroids per follicle. Eighty-eight follicles contained more than 10(4) anaerobic diphtheroids. Using data from scalp biopsies we found that there was a correlation between the weight of sebaceous glands and the density of anaerobes within the follicles attached to these glands (coefficient of correlation = 0.6).

The occurrence of twitching motility among gram-negative bacteria.

Almost 1000 strains representing well above 50 different species or groups of gram-negative bacteria were examined for twitching motility. This kind of motility was mainly found in strictly aerobic cocci and rods (viz. Acinetobacter calcoaceticus, Moraxella spp., Neisseria gonorrhoeae, N. meningitidis, Pseudomonas spp., phenon 3 of Thornley that is closely related to Acinetobacter, and marine, yellow-pigmented rods), but also in the facultative Eikenella corrodens and in anaerobic strains presumptively identified as "Bacteroides corrodens" earlier. Strains of species known to possess polar fimbriae were shown to exhibit twitching motility. None of the strains of species known to possess peritrichously arranged fimbriae exhibited twitching motility.

Quantitative Microbiology of the Scalp in Non-Dandruff, Dandruff, and Seborrheic Dermatitis

The composition of the scalp microflora was assessed quantitatively in normal individuals and in patients with dandruff and seborrheic dermatitis, disorders characterized by increasing scaling. Three organisms were constantly found: (1) Pityrosporum, (2) aerobic cocci, and (3) Corynebacterium acnes. Pityrosporum (mainly Pityrosporum ovale) made up 46% of the total microflora in normals, 74% in dandruff, and 83% in seborvheic dermatitis. The geometric mean number of organisms per cm-2 in non-dandruff subjects was 5.04 times 10-5; 9.22 times 10-5 in dandruff subjects; and 6.45 times 10-5 in those with seborrheic dermatitis. The cocci were dominantly Baird-Parker type SII and no quantitative or qualitative change occurred in the scaling disorders. C. acnes comprised 26% of the flora on the normal scalp, 6% in dandruff, and only 1% in seborrheic dermatitis. These results differ significantly from previous reports which describe a much more complex microflora and suggest an etiologic role for microorganisms in dandruff.

A serological method for distinguishing coagulase-negative staphylococci from micrococci.

Absorbed antisera prepared against heat-killed suspensions of a coagulase-negative staphylococcus and of a micrococcus were used in a slide-agglutination test. A collection of 176 coagulase-negative aerobic cocci, from which Staphylococcus aureus had been excluded, was classified into staphylococci and micrococci by means of the test for anaerobic utilization of glucose. Of 113 staphylococci, 99 reacted with the anti-staphylococcus serum, seven with the micrococcus serum, and seven with neither; of 63 micrococci, 55 reacted with the micrococcus serum and eight were untypable. Thus 161 of 176 strains (91%) were classifiable serologically, and in 154 of 161 instances (95%) the results of the serological and biochemical classification were in agreement.

Influence of Pityrosporum Species in the Generation of Free Fatty Acids in Human Surface Lipids

The importance of lipid dependent yeasts in the hydrolysis of triglycerides in human skin was investigated by selective antibiotic therapy and monitoring of the lipid composition and the microbial flora in healthy volunteers. The yeast density was reduced with topical amphotericin treatment. In the presence of high populations of Corynebacterium acnes, lipid composition was unchanged. When C. acnes was also inhibited by systemic demethylchlortetracycline, triglyceride hydrolysis was reduced to very low levels. The aerobic cocci were not implicated in lipid hydrolysis.

Studies onBacillus amylobacter, A. M. et Bredemann

(1) An aerobic coccus has been obtained from cultures of the motile butyric acid bacillus under conditions which exclude the possibility of contamination.(2) Descriptions of the coccus and the bacillus are given.(3) The coccus does not fix nitrogen in soil extract containing dextrose.