Survival of Staphylococcus epidermidis on the skin of patients of lepromatous leprosy

The effect of hydration on Staphylococcus epidermidis, the predominant resident bacterial flora, was studied on skin affected by leprosy and known to have impaired sweating. Normal areas served as control. Significantly higher bacterial counts were observed in affected areas compared with normal-looking skin in 16/19 of the patients. Artificial application of Staph. epidermidis on leprosy-affected and unaffected areas, however, showed equivocal results, as in only 50% of the patients were higher counts obtained in affected compared with unaffected sites. The possible responsible factors for the present observation are discussed.     

The Location of Bacteria in Skin

The Castroviejo Keratotome has been used in an attempt to determine the quantitative distribution of bacteria within various thicknesses of pig skin. Results of bacterial counts obtained from serial sections of pig skin indicated that even after vigorous washing, which would remove most of the "transient"surface bacteria, the majority of bacteria were found in the outer 0·3 mm, with decreasing numbers in progressively deeper sections. The results obtained from closely adjacent areas of pig skin from the same animal were comparable, but there were occasional high counts. This indicated that the distribution of bacteria along the skin surface was not constant. The possibility that these high counts were derived from areas immediately above a gland is discussed. The results of bacterial counts made on surface sections of human skin removed with the Keratotome are also presented.     

Comparison of methods for quantitative determinations of airborne bacteria and evaluation of total viable counts.

Three different methods of estimating airborne bacteria were compared. An Anderson sampler, a slit sampler, an impinger, and filter samplers with gelatine filters or membrane filters were tested for collection efficiency. The comparisons were made in laboratory experiments with an aerosol of Staphylococcus epidermidis or Serratia marcescens, in field experiments in two different industries, i.e., cotton mill and sewage plant, and in experiments with skin fragment sampling. Experiments were also performed estimating the total number of viable microorganisms on the airborne particles. The Andersen sampler gave the highest bacterial counts in all environments tested. The slit sampler gave statistically lower counts only in the aerosol experiments and cotton mill experiments, where the size of the majority of the particles carrying visible bacteria was 2 to 6 micrometers or smaller. In the sewage plant and skin fragment experiments, where the particles were mainly 5 micrometers or larger, the difference was not significant. The filters were efficient in sampling in skin fragment experiments only. With the agar impingement method, the total viable cell count showed a rising index value with increasing particle size. A mean of 13 bacteria was found per particle in the cotton mill, a mean of 24 in the sewage plant, and a mean of 147 in skin fragment experiments.     

CD57 Expression and Cytokine Production by T Cells in Lesional and Unaffected Skin from Patients with Psoriasis

Background

The immunopathogenic mechanisms leading to psoriasis remain unresolved. CD57 is a marker of replicative inability and immunosenescence on CD8+ T cells and the proportion of CD57 expressing CD8+ T cells is increased in a number of inflammatory conditions.

Methodology

We examined the expression of CD57 on T cells in the skin of patients affected with psoriasis, comparing lesional and unaffected skin. We also assessed functionality of the T cells by evaluating the secretion of several inflammatory cytokines (IL-17A, IFN-gamma, IL-2, IL-33, TNF-alpha, IL-21, IL-22, and IL-27), from cell-sorted purified CD4+ and CD8+ T cells isolated from lesional and unaffected skin biopsies of psoriasis patients.

Principal Findings

We observed that the frequency of CD57+CD4+ and CD57+CD8+ T cells was significantly higher in unaffected skin of psoriasis patients compared to lesional skin. Sorted CD4+ T cells from psoriatic lesional skin produced higher levels of IL-17A, IL-22, and IFN-gamma compared to unaffected skin, while sorted CD8+ T cells from lesional skin produced higher levels of IL-17, IL-22, IFN-gamma, TNF-alpha, and IL-2 compared to unaffected skin.

Conclusions/Significance

These findings suggest that T cells in unaffected skin from psoriasis patients exhibit a phenotype compatible with replicative inability. As they have a lower replicative capacity, CD57+ T cells are less frequent in lesional tissue due to the high cellular turnover.     

Preliminary Investigation: Acupoint-Skin Conductance in Stroke Survivors

It has been reported that patients with rheumatoid arthritis or asthma have skin conductance over the acupoints that is lower than that of their healthy counterparts; this has been regarded as indirect evidence of the existence of acupoints and the energy-based model of diseases. In order to investigate the potential application of acupoint-skin conductance measurement that may reflect pathology of ischemic stroke, the present study recruited 34 stroke survivors with hemiparesis, whose skin conductance of a hand acupoint and an adjacent non-acupoint and the finger temperature in both affected and unaffected hands were simultaneously measured; the data revealed that the skin conductance and finger temperature were statistically higher in the unaffected hand than that of the affected, and the skin conductance of the acupoint and the non-acupoint were comparable in the affected and unaffected hands respectively. We attribute the observed drop in the skin conductance to the diminished peripheral blood flow of the affected hand that is signified by relatively lower finger temperature. As such, it should be advisable when studying skin conductance over acupoints, monitoring the adjacent non-acupoint skin and local vascular circulation is essential.     

Adhesion of coagulase-negative staphylococci to biomaterials

The adhesion of two Staphylococcus epidermidis strains and one Staphylococcus saprophyticus strain on to poly(tetrafluorethylene-co-hexafluorpropylene) (FEP)-fluorocarbon and cellulose acetate was studied in vitro. Both S. epidermidis strains showed a more hydrophobic character than the encapsulated S. saprophyticus as determined by the bacterial affinity towards xylene. Staphylococcus epidermidis showed a significantly higher adhesion on to the hydrophobic FEP than S. saprophyticus. The adhesion of staphylococci on to the more hydrophilic cellulose acetate was always low. Treatment of S. epidermidis with pepsin or extraction with aqueous phenol yielded cells with a decreased hydrophobicity, which resulted in a decreased adhesion on to FEP. Cells with a decreased hydrophobicity showed a lower rate of reaggregation in suspension. The hydrophobicity and the adhesion on the FEP of S. epidermidis were not affected by exposure to a subminimal inhibitory concentration of penicillin. The strong interaction between S. epidermidis and FEP, which appeared not to be influenced by the age or the metabolic stage of the bacteria, is mainly caused by hydrophobic bonding.     

淤积性皮炎与皮肤菌群关系的研究

目的：探讨淤积性皮炎与皮肤菌群之间的关系。方法：对21例小腿淤积性皮炎患者皮损，邻近皮肤及鼻孔的皮肤菌群进行检测。并将结果同20例正常人小腿皮肤及鼻孔菌群做了比较，其数据进行统计学处理。结果：金黄色葡萄球菌为淤积性皮炎患者皮肤的主要菌种，其分离率及密度均高于正常对照组。结论：金黄色葡萄球菌可能是淤积性皮炎发生的一个重要因素。     

Staphylococci in the skin microbiocenosis of the breasts in pregnant women

The microflora of the mammary glands in the area of the nipple, the areola and the adjacent skin was studied by the methods of washings and impression. 120 nonpregnant women and 164 pregnant women were examined. The pregnant women showed a higher level of the contamination of the above-mentioned sites. The highest density of bacterial population was detected in the area of the nipple and the lowest density, on the skin surrounding the areola. Coagulase-negative staphylococci proved to be the most numerous organisms among all bacterial population found on the skin of the mammary glands of pregnant women. Of these staphylococci, S. epidermidis was most frequently isolated, its isolation rate being higher in the pregnant women than in the nonpregnant ones.     

血清降钙素原与传统感染检测指标对细菌性血流感染的临床诊断价值比较

目的比较血清降钙素原(PCT)和传统感染检测指标在细菌性血流感染中的诊断价值。方法选取我院2018年1月至11月59例血培养显示细菌感染阳性患者为血培养阳性组,选取同期63例血培养阴性患者为血培养阴性组,分析两组患者白细胞(WBC)、中性粒细胞(NEU)计数和血清PCT水平,比较PCT、WBC和NEU对细菌性血流感染的诊断阳性率和ROC曲线下面积。结果两组患者WBC、NEU计数和血清PCT水平差异均有统计学意义(均P<0.05),PCT对细菌性血流感染的诊断阳性率和ROC曲线下面积显著大于WBC和NEU(均P<0.05)。PCT诊断细菌性血流感染的灵敏度为96.6%,特异度为95.2%。结论血清PCT对细菌性血流感染具有较高的诊断价值。     

青少年痤疮面部皮肤微生物群落结构变化

【背景】青少年痤疮是一种最常见的慢性炎症性损容性皮肤病,与痤疮丙酸杆菌的异常增殖有关。【目的】探究痤疮皮损区与附近无明显皮损区微生物组成与健康对照的差异,为从微生态角度防治痤疮提供理论基础。【方法】利用细菌16S rRNA基因V1-V2区和真菌TIS1高通量测序技术分析北京地区16岁青少年面部痤疮皮肤细菌和真菌群落结构,将痤疮皮损区与附近无明显皮损区微生物组成与健康组进行比较,寻找差异菌群。【结果】痤疮患者面部皮损区与附近无明显皮损区细菌多样性(Shannon指数)较健康对照组显著性降低(P0.001),主要与丙酸杆菌(痤疮丙酸杆菌)和葡萄球菌(表皮葡萄球菌PM221)显著性上升相关,而痤疮皮损区与附近未明显皮损区细菌组成无显著性差异。痤疮患者皮损区与附近无明显皮损区较健康对照组真菌丰富度(Chao1指数)显著性上升(P0.05),与限制性马拉色菌的显著上升相关。【结论】面部皮肤微生物变化与青少年痤疮的发生相关。本研究为从微生物角度防治痤疮提供理论依据。     

Bacteriological examination of a modern animal house containing small laboratory animals.

Floors and other areas totalling 1800 m2, comprising conventional and specified-pathogen-free (SPF) units, were screened bacteriologically 6 times in a year. The contamination indices observed were lower within than outside the units, and lower in the SPF than in the conventional unit. Bacterial counts in rooms containing animals in the conventional and SPF units were very similar. In all of the areas investigated within the units, most of the samples revealed less than 2 colony forming units per cm2. In contrast, high degrees of bacteriological contamination were detected in the changing rooms after showering or washing before entry. Staphylococcus epidermidis was the dominant bacterial species isolated. The bacteriological spectrum did not vary between the areas surveyed.     

Lack of biofilm contribution to bacterial colonisation in an experimental model of foreign body infection by Staphylococcus aureus and Staphylococcus epidermidis

The contribution of in vivo biofilm-forming potential of Staphylococcus aureus and Staphylococcus epidermidis was studied in an experimental model of foreign body infections. Increasing inocula (from 10(2) to 10(7) organisms) of ica-positive strains of S. aureus and S. epidermidis and their ica-negative isogenic mutants (the ica locus codes for a major polysaccharide component of biofilm) were injected into subcutaneously implanted tissue cages in guinea pigs. Surprisingly, bacterial counts and time-course of tissue cage infection by ica-positive strains of S. aureus or S. epidermidis were equivalent to those of their respective ica-negative mutants, in the locally infected fluids and on tissue-cage-inserted plastic coverslips.     

Evaluation of antimicrobial effects of novel implant materials by testing the prevention of biofilm formation using a simple small scale medium-throughput growth inhibition assay

Staphylococcal colonization of implants is a serious complication of orthopaedic surgery. Anti-infectious modification of implant surfaces may serve to prevent bacterial colonization. The authors set out to develop an in vitro test system for the analysis of prevention of biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus on implant materials. Biofilm growth was monitored over 10 days on titanium disks in order to develop appropriate test parameters. Bacterial cell counts following ultrasonic treatment of the colonized samples were compared with scanning electron microscope images of the specimens. Copper ion containing surfaces (ie copper [Cu] and inter-metallic Ti-Cu films) were used for growth inhibition assays: copper ion releasing specimens led to reduced bacterial numbers in biofilms and decreased bacterial persistence in the model used. The assay used represents an inexpensive and quick in vitro screen for the antibacterial effects of novel implant surface materials.     

The distribution and ecology of Malassezia furfur and cutaneous bacteria on human skin

The prevalence and abundance of Malassezia furfur on clinically normal skin at 20 sites has been determined. All of the 16 subjects studied (young adults) had high counts on the upper trunk and on at least one site on the head. Counts obtained from the lower trunk and upper thighs of male subjects were considerably higher than those from female volunteers. Organisms isolated, grouped according to their colony morphologies, had distributions consistent with those noted for 'Pityrosporum ovale' and 'P. orbiculare' in previous studies. Mean M. furfur counts were compared with aerobic and anaerobic bacterial counts performed at the same sites. Propionibacteria and M. furfur distributions were similar but not identical. Some factors which might limit the range of M. furfur are discussed.     

Local and Systemic Cytokine Expression in Patients with Postherpetic Neuralgia

Background

Postherpetic neuralgia (PHN) is the painful complication of a varicella zoster virus reactivation. We investigated the systemic and local gene expression of pro- and anti-inflammatory cytokine expression in patients with PHN.

Methods

Thirteen patients with PHN at the torso (Th4-S1) were recruited. Skin punch biopsies were obtained from the painful and the contralateral painless body area for intraepidermal nerve fiber density (IENFD) and cytokine profiling. Additionally, blood was withdrawn for systemic cytokine expression and compared to blood values of healthy controls. We analyzed the gene expression of selected pro- and anti-inflammatory cytokines (tumor necrosis factor-alpha [TNF] and interleukins [IL]-1β, IL-2, and IL-8).

Results

IENFD was lower in affected skin compared to unaffected skin (p<0.05), while local gene expression of pro- and anti-inflammatory cytokines did not differ except for two patients who had 7fold higher IL-6 and 10fold higher IL-10 gene expression in the affected skin compared to the contralateral unaffected skin sample. Also, the systemic expression of cytokines in patients with PHN and in healthy controls was similar.

Conclusion

While the systemic and local expression of the investigated pro- and anti-inflammatory cytokines was not different from controls, this may have been influenced by study limitations like the low number of patients and different disease durations. Furthermore, other cytokines or pain mediators need to be considered.     

Use of a modified Robbins device to directly compare the adhesion of Staphylococcus epidermidis RP62A to surfaces

Staphylococcus epidermidis is a frequent cause of infection associated with the use of biomedical devices. Flow cell studies of the interaction between bacteria and surfaces do not generally allow direct comparison of different materials using the same bacterial suspension. The use of a modified Robbins Device (MRD) to compare the adhesion to different surfaces of Staph. epidermidis RP62A grown in continuous culture was investigated. Adhesion to glass was compared with siliconized glass, plasma-conditioned glass, titanium, stainless steel and Teflon. Attachment to siliconized glass was also compared with glass under differing ionic strength, and divalent cation concentrations. Both the differences in numbers adhering and changes in adhesion (slope) through the MRD were compared. There was a trend towards higher numbers adhering to the discs at the in-flow end of the MRD than at the outflow end, probably reflecting depletion of adherent bacteria in the interacting stream. Adhesion of Staph. epidermidis RP62A to siliconized glass and Teflon was reduced when compared to glass with increasing flow rates. Adhesion to stainless steel was not affected by flow rate and titanium gave a different slope of adhesion through the MRD when compared with glass, suggesting an interaction with different sub-populations within the interacting stream. Differences between siliconized glass and glass at flow rates of 300 ml h-1 were abolished by the addition of calcium or EDTA and reduced by the addition of magnesium. Increasing ionic strength reduced the statistical significance of the differences between glass and siliconized glass. Pre-conditioning of glass with pooled human plasma reduced adhesion compared with untreated glass and again gave a different slope to glass. The MRD linked to a chemostat can be used to compare directly bacterial adhesion to potential biomaterials. Variable depletion of the interacting stream should be taken into account in the interpretation of results. Divalent cation concentration, substrate properties and flow rate were important determinants of the comparative adhesion of Staph. epidermidis RP62A to surfaces.     

The distribution and ecology of Malassezia furfur and cutaneous bacteria on human skin

The prevalence and abundance of Malassezia furfur on clinically normal skin at 20 sites has been determined. All of the 16 subjects studied (young adults) had high counts on the upper trunk and on at least one site on the head. Counts obtained from the lower trunk and upper thighs of male subjects were considerably higher than those from female volunteers. Organisms isolated, grouped according to their colony morphologies, had distributions consistent with those noted for ' Pityrosporum ovale 'and ' P. orbiculare 'in previous studies. Mean M. furfur counts were compared with aerobic and anaerobic bacterial counts performed at the same sites. Propionibacteria and M. furfur distributions were similar but not identical. Some factors which might limit the range of M. furfur are discussed.     

Interferon-alpha and interferon-gamma reduce excessive collagen synthesis and procollagen mRNA levels of scleroderma fibroblasts in culture

The effects of interferon-alpha and interferon-gamma on collagen synthesis and mRNA levels of type I and type III procollagens were studied in skin fibroblasts cultured from affected and unaffected skin sites of two patients with localized scleroderma (morphea). Both scleroderma cell lines exhibited elevated type I and type III procollagen mRNA levels to account for the increased procollagen synthesis, when compared to the unaffected controls. Interferon-gamma treatment resulted in a dose-dependent reduction in collagen synthesis and procollagen mRNA levels in scleroderma fibroblasts. A 72-h exposure to interferon-gamma reduced procollagen mRNA levels in the scleroderma fibroblast lines to the levels exhibited by the unaffected control fibroblasts. The suppressive effect of interferon-alpha on procollagen mRNA levels was somewhat weaker than that of interferon-gamma. The results suggest potential use of interferon-gamma in treatment and prevention of human fibrotic conditions.     

Culture-dependent bacteria in commercial fishes: Qualitative assessment and molecular identification using 16S rRNA gene sequencing

Fish contamination has been extensively investigated along the Saudi coasts, but studies pertaining to bacterial pathogens are scarce. We conducted qualitative assessment and molecular identification of culture-dependent bacteria in 13 fish species from three coastal sites and a local fish market in Jeddah, Saudi Arabia. Bacterial counts of gills, skin, gut and muscle were examined on agar plates of Macconkey’s (Mac), Eosin Methylene Blue (EMB) and Thiosulfate Citrate Bile Salts (TCBS) culture media. Bacterial counts significantly differed between species, sources and feeding habits of examined fishes. Mugil cephalus exhibited higher counts on TCBS (all body parts), Mac (gills, muscle and gut) and EMB (gills and muscle). Fishes from Area I had higher bacterial loads, coinciding with those in seawater and sediment from the same site, indicating direct association between habitat conditions and the levels of bacterial contamination. By feeding habit, detritivorous fish harbored higher counts than herbivorous and carnivorous species. Bacterial counts of skin were higher in fish from market than field sites, and positively correlated with other body parts indicating the relation of surface bacterial load on the overall quality of fish. Rahnella aquatilis (Enterobacteriaceae) and Photobacterium damselae (Vibrionaceae) were among the dominant species from fish muscle based on 16S rRNA sequencing. These species are known human pathogens capable of causing foodborne illness with severe antibiotic resistance. Opportunistic pathogens, e.g. Hafnia sp. (Enterobacteriaceae) and Pseudomonas stutzeri (Pseudomonadaceae) also occurred in fish muscle. The inclusion of bacterial contamination in future monitoring efforts is thus crucial.     

Polysaccharide intercellular adhesin (PIA) protects Staphylococcus epidermidis against major components of the human innate immune system

The skin commensal and opportunistic pathogen Staphylococcus epidermidis is the leading cause of nosocomial and biofilm-associated infections. Little is known about the mechanisms by which S. epidermidis protects itself against the innate human immune system during colonization and infection. We used scanning electron microscopy to demonstrate that the exopolysaccharide intercellular adhesin (PIA) resides in fibrous strands on the bacterial cell surface, and that lack of PIA production results in complete loss of the extracellular matrix material that has been suggested to mediate immune evasion. Phagocytosis and killing by human polymorphonuclear leucocytes was significantly increased in a mutant strain lacking PIA production compared with the wild-type strain. The mutant strain was also significantly more susceptible to killing by major antibacterial peptides of human skin, cationic human beta-defensin 3 and LL-37, and anionic dermcidin. PIA represents the first defined factor of the staphylococcal biofilm matrix that protects against major components of human innate host defence.