Bacteriological examination of inflamed epidermal cysts: a survey between 2008 and 2009 at a hospital in southern Taiwan

BackgroundInflamed epidermal cysts are common clinical conditions, and they frequently form abscesses. We designed a study to delineate the bacteriology of inflamed epidermal cysts.MethodsWe enrolled 61 adult patients with inflamed epidermal cysts characterized by surface erythema, with or without tenderness, or localized abscess formation within the cyst cavity. Incision and drainage of the cysts were performed, and the contents were sent for aerobic and anaerobic bacterial culture. The locations of the cyst and culture results were recorded for statistical analysis.ResultsA total of 61 cysts and 122 cultures were obtained. The most common locations of the inflamed cysts were the face, neck, and scalp (34.4%), followed by the trunk (32.8%), then the buttocks, inguinal areas, perineum, and axillae (16.4%), and the extremities (16.4%). The culture results were positive in 88.5% of patients, and anaerobes were more frequently isolated than were aerobes. Pure aerobes represented 31.1% of the cultures; pure anaerobes, 36.1%, and combined aerobes and anaerobes, 21.3% (n = 13). The most common anaerobic organisms found were Propionibacterium spp (40.8%), followed by Peptostreptococcus spp (36.7%), Staphylococcus saccharolyticus (14.4%), Prevotella (4.1%), Bacteroides fragilis (2.0%), and Fusobacterium spp (2.0%). The most commonly isolated aerobes were Staphylococcus spp (40%), followed by Enterobacter spp (11.3%), Proteus mirabilis (8.5%), Citrobacter diversus (8.5%), Klebsiella pneumoniae (5.7%), Corynebacterium (5.7%), Morganella morganii (2.9%), Enterococcus faecalis (2.9%), group A β-hemolytic streptococcus (2.9%), Pseudomonas aeruginosa (2.9%), and Providencia rettgeri (2.9%).ConclusionsBoth aerobic and anaerobic microorganisms were present in the inflamed epidermal cysts, although the anaerobic bacteria, specifically, Propionibacterium spp and Peptostreptococcus spp, were isolated slightly more frequently. Antibiotics directed against anaerobes may be considered in the treatment regimen for inflamed epidermal cysts.     

Microorganisms inhabiting follicular contents of facial acne are not only Propionibacterium but also Malassezia spp.

To clarify the relationship between major cutaneous microorganisms (Propionibacterium, Staphylococcus and Malassezia spp.) and acne vulgaris (acne), we examined the microbiota quantitatively in the follicular contents of inflammatory acne and on the facial skin of patients with acne. Fifteen Japanese untreated acne outpatients were studied. The follicular contents from inflammatory acne lesions of the face were collected using a comedo extractor. The skin surface samples were obtained by the swab method from 10 cm² of facial skin. The microbiota was analyzed using polymerase chain reaction. The microbiota in follicular contents was similar to that on the skin surface, namely, there were large populations of Propionibacterium spp., Staphylococcus spp. and Malassezia spp. Moreover, the number of Malassezia spp. on the skin surface was correlated with that of inflammatory acne and that in follicular contents. This study clarified that there are large populations of Propionibacterium spp., Staphylococcus spp. and Malassezia spp. in follicular contents. These results suggest the possibility that not only Propionibacterium acnes but also other cutaneous resident microorganisms are related to acne. Particularly, we considered that Malassezia spp. is closely related.     

MICROBIOLOGY OF INFECTED ATOPIC DERMATITIS

Background. Bacterial infections occur frequently in lesions of atopic dermatitis (AD). The objectives of the study were to establish the aerobic and anaerobic microbiology of secondarily infected AD. Methods. A retrospective review was carried out of clinical and microbiology laboratory records and of data obtained from patients with secondarily infected AD lesions, whose specimens of infected sites were processed for the presence of aerobic and anaerobic bacteria. Results. Bacterial growth was noted in 41 specimens. Aerobic or facultative anaerobic bacteria only were present in 15 patients (36%), anaerobic bacteria only in eight (20%), and mixed anaerobic-aerobic flora was present in 18 (44%). Seventy- two isolates were recovered (1.8 per specimen), 34 aerobic or facultative bacteria, 35 strict anaerobes, and three Candida sp. The predominant aerobic and facultative bacteria were Staphylococcus aureus (12 isolates). Group A beta hemolytic streptococcus in five isolates, and Escherichia coli in four. The predominant anaerobes were peptostreptococcus spp. (13 isolates), pigmented Prevotella and Porphyromonas spp. in eight, and Fusobacterium spp. in four isolates. Single bacterial isolates were recovered in 14 patients (34%), seven of which were S. aureus. Twenty-one of the organisms isolated from 16 patients (39%) produced the enzyme beta-lactamase. Organisms that resided in the mucous membranes close to the lesions predominated in these infections. Enteric gram-negative rods and bacteroides fragilis group predominated in lesions on legs and buttocks. Group A beta-hemolytic streptococci, pigmented Prevotella, and Porphyromonas and Fusobacterium spp. were most frequently recovered in lesions of the finger, scalp, face, and neck. Conclusions. The polymicrobial etiology of secondarily infected AD lesions and the association of bacterial flora with the anatomic site of the lesions are demonstrated.     

Quantitative studies of vaginal bacteria.

A quantitative method of culture, based on a weighed sample and with results expressed as colony forming units (cfu)/g was assessed and used to investigate the vaginal flora of normal women and that of women with vaginal disease. Samples were collected by means of disposable plastic loops into modified proteose peptone water transport medium in preweighed bottles. Counts expressed as cfu/g of secretion were consistent, whereas counts expressed as cfu/ml were inconsistent. Results obtained with specimens manipulated on the open bench were the same as those from duplicate samples processed in an anaerobic chamber. The normal vaginal flora was predominantly aerobic--lactobacilli, coryneforms, and coagulase negative staphylococci--with counts of greater than or equal to 10(8) cfu/g for lactobacilli. These were also present in patients with candidosis, but the flora in patients with trichomoniasis, bacterial vaginosis, gonorrhoea, or chlamydial infection was predominantly anaerobic. The commonest anaerobes were Bacteroides spp, particularly B bivius; they were found in 55% of controls but at counts of 10(2) cfu/g lower than in the patients, most of whom had high counts of anaerobes (greater than 10(8) cfu/g). The isolation rate of Gardnerella vaginalis was not appreciably greater from patients with bacterial vaginosis, and the quantitative cultures on controls and patients who were G vaginalis positive were the same (approximately equal to 10(7) cfu/g). Quantitative studies show greater differences than qualitative cultures between normal controls and patients with vaginal infections, indicating that some symptoms and signs of such infections may be related to quantitative polymicrobial changes.     

An analysis of sebum excretion rate, bacterial population and the production rate of free fatty acids on human skin

Bacteria were sampled using a ‘scrub’ technique from the skin surface of the faces of forty-nine female subjects aged 18–21 years. The sebum excretion rate was determined by a gravimetric method and the level of free fatty acids by titration. The production rate of free fatty acids was calculated from the product of the concentration of free fatty acids in the sebum and the sebum excretion rate. The date were analysed using Kendall's rank correlation method. Positive correlations existed between the number of Micrococcaceae and the skin propionibacteria (P < 0.001) and between both groups of organisms and the production rate of free fatty acids (P < 0.001). There was no significant correlation between the size of the bacterial population and the sebum excretion rate. The results support the view that free fatty acids are produced as a result of bacterial action, that the Micrococcaceae and skin propionibacteria do not compete to the detriment of their respective populations, and that the size of the bacterial population is not dependent upon the sebum excretion rate.     

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 therapy. A transient rise in Staphylococcus aureus counts was thought to be due to the use of emollients rather than to an 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.     

Characterization of the major bacterial–fungal populations colonizing dandruff scalps in Shanghai,China, shows microbial disequilibrium

Dandruff is a scalp disorder characterized by the formation of flaky white‐yellowish scales due to an altered proliferation and differentiation status; a disrupted barrier function; a decrease in the level of hydration and of natural moisturizing factors (NMF) in the scalp, with a persistent and relapsing inflammatory condition. It was recently reported that an imbalance between bacterial and fungal species colonizing the scalp of French volunteers was associated with dandruff condition. The purpose of the present study was to analyze the major bacterial and fungal species present on the scalp surface of Chinese volunteers and to investigate possible region‐related variation in the microbiota linked to dandruff condition. The data obtained from the Chinese populations were highly similar to those obtained in France, confirming that dandruff scalps are associated with a higher incidence of Malassezia restricta and Staphylococcal sp. The ratios of Malassezia to Propionibacterium and Propionibacterium to Staphylococcus were also significantly higher in the dandruff volunteers as compared to normal volunteers, suggesting that equilibrium between the major bacterial and fungal taxa found on the normal scalps is perturbed in the dandruff scalps. The main difference between the French and Shanghai subjects was in their Staphylococcal biota. The results obtained in China and in France suggest that targeting one particular Malassezia sp. by antifungals instead of using large spectrum antifungals and rebalancing the dandruff scalp microbiota could be common approach to improve dandruff condition in the two countries.     

The role of the skin microbiome in atopic dermatitis: a systematic review

Dysbiosis is a hallmark of atopic dermatitis (AD). The composition of skin microbiome communities and the causality of dysbiosis in eczema have not been well established. The objective of this review is to describe the skin microbiome profile in AD and address whether there is a causal relationship between dysbiosis and AD. The protocol is registered in PROSPERO (CRD42016035813). We searched PubMed, Embase, Scopus and ClinicalTrials.gov for primary research studies applying culture‐independent analysis on the microbiome on AD skin of humans and animal models. Two authors independently screened the full text of studies for eligibility and assessed risk of bias. Because of heterogeneity no quantitative synthesis was done. Of 5735 texts, 32 met the inclusion criteria (17 published: 11 human and six animal studies). The studies varied in quality and applied different methodology. The skin in AD had low bacterial diversity (lowest at dermatitis‐involved sites) and three studies showed depletion of Malassezia spp. and high non‐Malassezia fungal diversity. The relative abundance of Staphylococcus aureus and Staphylococcus epidermidis were elevated and other genera were reduced, including Propionibacterium. A mouse study indicated that dysbiosis is a driving factor in eczema pathogenesis. The data are not sufficiently robust for good characterization; however, dysbiosis in AD not only implicates Staphylococcus spp., but also microbes such as Propionibacterium and Malassezia. A causal role of dysbiosis in eczema in mice should encourage future studies to investigate if this also applies to humans. Other important aspects are temporal dynamics and the influence of methodology on microbiome data.     

Microbiology of perianal cellulitis in children: comparison of skin swabs and needle aspiration

Objective To establish the aerobic and anaerobic microbiology of perianal cellulitis in children, comparing skin swab and needle aspirate methodology. Method Swabs of involved skin and needle aspirates of cellulitis were studied for aerobic and anaerobic bacteria. Results Specimens obtained from 10 patients with perianal cellulitis showed bacterial growth. Polymicrobial aerobic–anaerobic flora was found in all skin surface cultures, where the predominate isolates were Peptostreptococcus spp., Escherichia coli, and alpha hemolytic streptococci. The number of isolates in needle aspirates varied between one and two. The predominant ones were E.coli (3), Peptostreptococcus spp. (3), Staphylococcus aureus (2), and Bacteroides fragilis group (2). Complete or partial concordance in microbiology between skin swabs and needle aspirates was present in six instances. In four instances, isolates recovered from needle aspirates were not isolated from the skin surface. Conclusions This study demonstrates the diversity of aerobic and anaerobic organisms isolated from perianal cellulitis, and the superiority of needle aspirates in establishing the microbiology of the infection.     

Microbiology of infected poison ivy dermatitis

We report the aerobic and anaerobic microbiology of secondarily infected poison ivy dermatitis. The study involved retrospective review of clinical and microbiology laboratory records of patients with secondarily infected poison ivy lesions. Bacterial growth was noted in 33 specimens. Aerobic or facultative anaerobic bacteria only were present in 18 (55%) patients, anaerobic bacteria only in seven (21%), and mixed anaerobic-aerobic bacteria in eight (24%). Forty-five isolates were recovered (1.4 per specimen): 27 aerobic or facultative anaerobic bacteria, and 18 strict anaerobes. The predominant aerobic and facultative anaerobic bacteria were Staphylococcus aureus (13 isolates) and group A beta-haemolytic streptococci (six). The predominant anaerobes were Peptostreptococcus spp. (seven isolates), pigmented Prevotella and Porphyromonas spp. (four) and Fusobacterium spp. (two). Single bacterial isolates were recovered in 18 (55%) patients, eight of which were S. aureus. Nineteen of the organisms isolated from 16 (48%) patients produced the enzyme beta-lactamase. Organisms that resided in the mucous membranes close to the lesions predominated in those infections. Enteric gram-negative rods and Bacteroides fragilis group predominated in leg and buttock lesions. Group A beta-haemolytic streptococci, pigmented Prevotella and Porphyromonas and Fusobacterium spp. were most frequently recovered from lesions of the finger, face and neck. The polymicrobial aetiology of secondarily infected poison ivy lesions, and the association of bacterial flora with the anatomical site of the lesions, are demonstrated.     

Microbiology of infected pustular psoriasis lesions

BACKGROUND: Bacterial infections can occur in lesions of pustular psoriasis (PP). The objective of this study was to establish the aerobic and anaerobic microbiology of secondarily infected PP. METHODS: A retrospective 10-year review was carried out of clinical and microbiology laboratory records from patients with secondarily infected PP lesions, whose specimens of infected sites were processed for the presence of aerobic and anaerobic bacteria. RESULTS: Bacterial growth was noted in 23 specimens. Aerobic or facultative anaerobic bacteria only were present in 12 patients (52%), anaerobic bacteria only in four (17%), and mixed anaerobic-aerobic flora was present in seven (30%). Thirty-six isolates were recovered (1.6 per specimen), 23 aerobic or facultative bacteria and 13 strict anaerobes. The predominant aerobic and facultative bacteria were Staphylococcus aureus (15 isolates), Group D Enterococcus (two isolates), and Escherichia coli (two isolates). The predominant anaerobes were Peptostreptococcus spp. (six isolates) and Bacteroides fragilis group, Propionibacterium acnes, and pigmented Prevotella spp. in two each. Single bacterial isolates were recovered in 14 patients (61%), 11 of which were S. aureus. Nineteen of the organisms isolated from 18 patients (78%) produced the enzyme beta-lactamase. S. aureus was isolated from all body sites. Organisms that resided in the mucous membranes close to the lesions predominated in these infections. Enteric Gram-negative rods and Bacteroides fragilis group predominated in lesions on the legs and buttocks. Group A beta-hemolytic streptococci, pigmented Prevotella, and Fusobacterium spp. were most frequently recovered in lesions of the hand. CONCLUSIONS: The polymicrobial etiology of secondarily infected PP lesions and the association of bacterial flora with the anatomic site of the lesions were demonstrated.     

In-vitro and in-vivo studies of human axillary odour and the cutaneous microflora

The axillary microflora of 34 male subjects were studied in relation to their underarm odour intensity. The predominant groups of micro-organisms were aerobic coryneforms, Micrococcaceae and propionibacteria. There was no competition for habitat between these groups (Fisher's exact test P greater than 0.05). There was an association between the population density of aerobic coryneforms and the intensity of odour (Spearman, P = 0.001). Dominance of aerobic coryneforms within the axillary microflora was associated with high odour intensity (chi 2, P = 0.005). An in-vitro odour model was developed using a diethyl ether extract of axillary skin incubated with test bacteria. Underarm odour was produced exclusively by aerobic coryneform bacteria. Of aerobic coryneforms, 71.4% were odour producers and these were identified as Corynebacterium xerosis.     

Aerobic and anaerobic microbiology of chronic venous ulcers

Abstract
Background The role of bacteria in the pathogenesis of chronic venous leg ulcers (CVLU) is unclear. The objective of the study was to establish the aerobic and anaerobic bacteriology of CVLU.
Methods A retrospective review was carried out of the clinical and microbiological laboratory records obtained from patients with CVLU. Microorganisms were grown from 43 specimens obtained from 41 patients.
Results Aerobic or facultative bacteria alone were present in 18 (42%) specimens, anaerobic bacteria only in three (7%), and mixed aerobic–anaerobic flora in 22 (51%).
In total, there were 97 isolates, 64 aerobic or facultative and 33 anaerobic, an average of 2.3 isolates per specimen (1.5 aerobes and 0.8 anaerobes). The predominant aerobic organisms were Staphylococcus aureus (26 isolates), group D streptococci (5), and Escherichia coli (5). The predominant anaerobes were Peptostreptococcus spp. (15), Bacteroides fragilis group (6), Propionibacterium acnes (4), and Prevotella spp. (3).
Conclusions CVLU have a polymicrobial aerobic–anaerobic flora.     

Microbiology of Nonbullous Impetigo

Abstract: Our objective was to establish the aerobic and anaerobic microbiology of nonbullous impetigo (Nl) in children. We used a retrospective review of clinical microbiology laboratory and patients'records. Specimens were obtained from 40 patients with Nl lesions and showed bacteriai growth. Aerobic or facultative anaerobic bacteria only were present in 24 patients (60%), strict anaerobic bacteria only in 5 patients (12.5%), and mixed anaerobic-aerobic flora was present in 11 patients (27.5%). Sixty-four isolates were recovered (1.6 per specimen): 43 aerobic or facultative, and 21 anaerobic. The predominant aerobic and facultative bacteria were Staphylococcus aureus (29 isolates). Group A beta hemolytic streptococcus (GABHS) (13 Isolates), and Escherichia coli (1 isolate). The predominant anaerobes were Peptostreptococcus spp. (12), pigmented Prevotella spp. (5), Fusobacterium spp. (2), and Bacteroides fragilis (1). Single bacterial isolates were recovered in 17 patients (42.5%), 13 of which were S. aureus. S. aureus alone or mixed with GABHS or Peptostreptococcus spp. were isolated from all body sites. Mixed flora of Peptostreptococcus spp. with Prevotella spp. or Fusobacterium spp. was mostly found in infections of the head and neck, while E. coli mixed with B. fragills and Peptostreptococcus spp. were isolated from one infection of the buttocks area. Thirty-three organisms isolated from 32 patients (80%) produced the enzyme beta-lactamase. This study demonstrates the polymicrobial aerobic-anaerobic microbiology of Nl lesions.     

The carriage of Malassezia furfur serovars A, B and C in patients with pityriasis versicolor, seborrhoeic dermatitis and controls

The aetiological role of Malassezia furfur in various dermatoses is controversial. The role of the three serovars of M. furfur in Malassezia-associated diseases has not been investigated. This study measured population densities of M. furfur serovars A. Band C. propionibacteria and Micrococcaceae on the chest, back, forehead, left and right cheeks of 10 patients with pityriasis versicolor, and 10 age- and sexmatched controls: and 10 patients with seborrhoeic dermatitis, and 10 age- and sex-matched controls. The population densities of M. furfur. propionibacteria and Micrococcaceae did not vary at a given site between patients and the corresponding control subjects. Malassezia furfu serovar A was found to be the predominant isolate on the chest and back of all four groups. but there was no difference in the distribution of serovars on the forehead and cheeks. No serovar was specifically associated with lesional skin in either disease. Thus, this data indicated that there was no difference in either the total population density of M. furfur or the distribution of serovars on lesional skin compared with control skin in either pityriasis versicolor or seborrhoeic dermatitis.     

Quantification of anaerobic diphtheroids on the skin.

The widely used technique for sampling skin bacteria employs a detergent (Triton X-100) in buffer solution to remove and suspend the microorganisms. The fraction of the total population of anaerobes on the forehead removed by scrubbing with this solution was estimated. We calculated that approximately 10% of the resident anaerobes were removed by one minute of scrubbing with the detergent solution and two 1-min washes remove approximately 19.5% of the resident anaerobes (8.8 X 10(5)/CM2).     

Bacteriological study of epidermal cysts

The aim of this study was to determine whether bacterial infection plays a significant role in the inflammatory process of epidermal cysts. Samples from 152 patients (115 cases of inflamed and 37 of uninflamed epidermal cysts) were subjected to aerobic and anaerobic bacterial culture and the isolates were investigated. The rate of bacterial growth and the recovered anaerobes were significantly greater in the inflamed than the uninflamed epidermal cysts. However, it is difficult to determine whether recovered isolates from epidermal cysts represent "infection" or "colonization". In conclusion, this study revealed the predominance of anaerobes in inflamed cysts, strongly suggesting that anaerobes play a role in the inflammatory process.     

The microbiology of infected and noninfected leg ulcers

BACKGROUND: A clinical study was undertaken to investigate and compare specifically the aerobic and anaerobic microbiology of infected and noninfected leg ulcers. METHODS: Leg ulcers, defined as being infected on the basis of clinical signs, were swab sampled and investigated for aerobic and anaerobic microorganisms using stringent isolation and identification techniques. RESULTS: Two hundred and twenty isolates were cultured from 44 infected leg ulcers, in comparison with 110 isolates from 30 noninfected leg ulcers. Statistical analysis indicated a significantly greater mean number of anaerobic bacteria per infected ulcer (particularly Peptostreptococcus spp. and Prevotella spp.) in comparison with the noninfected ulcer group (2.5 vs. 1.3, respectively) (P < 0.05). Also, anaerobes represented 49% of the total microbial composition in infected leg ulcers compared with 36% in noninfected leg ulcers. The mean numbers of aerobes per wound in the two ulcer groups were not statistically different (P > 0.05). The study failed to demonstrate a clear correlation between commonly implicated facultative pathogens and wound infection. The isolation rate of Pseudomonas aeruginosa was generally low and, although Staphylococcus aureus was a frequent isolate in both wound types, it was more prevalent in noninfected leg ulcers. CONCLUSIONS: This study has demonstrated the complex aerobic-anaerobic microflora which exists in leg ulcers, the prevalence of anaerobes in infected wounds, and a poor correlation between the presence of specific aerobic pathogens and wound infection. In view of these findings, the role of microbial synergistic interactions in the pathogenesis of chronic wound infection may be of greater clinical importance than the isolated involvement of any specific potential pathogen.     

Shiunko and Chuoko,topical Kampo medicines,inhibit the expression of gehA encoding the extracellular lipase in Cutibacterium acnes

Antimicrobial agents have been used for eradication of Cutibacterium (formerly Propionibacterium) acnes that is an exacerbation factor of the skin disease acne vulgaris. However, the use of antibiotics is associated with an increased risk of promoting the emergence of resistant bacteria and leading to skin dysbiosis. Traditional Japanese Kampo medicines, such as Keigairengyoto, are used to treat acne. However, there is incomplete understanding regarding their functional mechanism in treatment of acne. In this study, we examined the antimicrobial and anti‐lipase activity of the Kampo medicines used empirically for acne treatment. Three oral medicines, Keigairengyoto, Seijoboufuto and Jumihaidokuto, were found to inhibit the growth of C. acnes and decrease the lipase activity. Especially, Keigairengyoto caused remarkable decrease of bacterial lipase activity. Furthermore, topical medicines such as Shiunko and Chuoko significantly decreased the lipase activity in a dose‐dependent manner, without inhibiting C. acnes growth. The topical medicines were found to inhibit the expression of gehA, which codes for extracellular lipase. Our results indicate that Shiunko and Chuoko have potential as effective acne therapeutic agents, especially because they do not promote the emergence of antimicrobial‐resistant bacteria and skin dysbiosis.     

Normal axillary skin in various populations

The axillary microflora of 163 male and 122 female subjects was examined. Subjects were found to have either a coryneform or coccal dominated flora. Three hundred and sixty coryneform isolates were identified to generic level by cell-wall type. Axillary coryneforms were found to comprise 83%Corynebacterium, 5%Brevibacterium and 12% other coryneforms. There was a significant correlation between coryneform-dominated floras and the occurrence of erythrasma, trichomycosis axillaris and pronounced axillary odour.