Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “IMPETIGO”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources

Differentiation of cultured keratinocytes promotes the adherence of Streptococcus pyogenes.

Based on a consideration of the histopathology of nonbullous impetigo that shows localization of Streptococcus pyogenes to highly differentiated, subcorneal keratinocytes, we hypothesized that adherence of an impetigo strain of S. pyogenes would be promoted by terminal differentiation of keratinocytes. An assay was developed in which S. pyogenes adhered via pilus-like projections from the cell wall to the surface of cultured human keratinocytes in a time- and inoculum-dependent manner suggestive of a receptor-mediated process. Terminal differentiation of keratinocytes was induced by increasing the calcium concentration in the growth medium, and was confirmed by morphologic analysis using electron microscopy. Adherence of S. pyogenes was three and fourfold greater to keratinocytes differentiated in 1.0 and 1.5 mM calcium, respectively, compared with undifferentiated keratinocytes in 0.15 mM calcium. The presence of calcium during the adherence assay further enhanced adherence nearly twofold. Adherence occurred preferentially to sites of contact between adjacent keratinocytes, suggesting that the keratinocyte receptor may be a molecule involved in cell-to-cell adhesion. In contrast, nonpathogenic Streptococcus gordonii adhered poorly to keratinocytes regardless of their state of terminal differentiation, and adherence of a pharyngeal strain of S. pyogenes was twofold greater to undifferentiated than differentiated keratinocytes. This is the first report of in vitro adherence of S. pyogenes to keratinocytes in a manner that emulates human impetigo. Adherence of only the impetigo strain, and not the pharyngeal strain of S. pyogenes or the nonpathogenic S. gorgonii isolate, was promoted by keratinocyte differentiation. This result provides a model system for investigating the molecular pathogenesis of streptococcal skin infections.

Bacterial Adhesion↗

Topical mupirocin vs. systemic erythromycin treatment for pyoderma.

Although topical antibiotics have been considered less than effective agents in the treatment of "impetigo," recent experience suggests that topical therapy has a place as primary treatment of pyoderma and impetigo. This bacteriologically controlled, randomized study compared the safety and efficacy of mupirocin with oral erythromycin in the treatment of pyoderma and impetigo. A total of 29 mupirocin-treated and 30 erythromycin-treated patients completed the study. None of the mupirocin-treated patients reported adverse experiences compared with 4 erythromycin-treated patients who reported 6 adverse experiences. The mupirocin-treated group had a significantly higher benefit:risk ratio than the erythromycin-treated group as measured by the investigator's global evaluation (P = 0.01). Both treatments eradicated 100% of the two most common pathogens, Staphylococcus aureus and Streptococcus pyogenes. Results from this study demonstrate that mupirocin is as effective as systemic erythromycin ethylsuccinate for treatment of pyoderma and impetigo.

Administration, Topical↗

[Immunological investigations on pathogenesis of staphylococcal scalded skin syndrome].

Staphylococcal exfoliative toxin (ET) is an extracellular product of Staphylococcus aureus isolated from patients with staphylococcal scalded skin syndrome (SSSS) which includes Ritter's disease, bullous impetigo and staphylococcal scarlet fever, and has been regarded as the causative agent of SSSS. The ET has not only a splitting effect at the granular layer of skin in human and mice but also an immunogenicity to human and mice. Using experimental animals and clinical specimens of patients with or without SSSS, the immunological investigation were performed and following results were obtained. 1) When some inbred and congenic resistant strains of mice were immunized with serotype A ET (ETA), they were divided into the high anti-ETA antibody producers (high responders) and the low responders. The gene controlling antibody response to ETA in mice is located in the I-A subregion in the major histocompatible complex (H-2 complex), and its function seems to be at least related to antigen recognition at the T-lymphocyte level. 2) Neonatal mice are generally susceptible to ETA regardless of their H-2 haplo-type. However, the neonatal mice born to a high-responder mother immunized with ETA were resistant to the subcutaneous challenge of ETA, but those born to an immunized low-responder mother were susceptible to the challenge. 3) The relationship between susceptibility and immune response to ETA in some mammalians could be divided into three groups: the possession of resistant skin and high production of antibody to ETA (rabbits and rats); the possession of resistant skin and low production of antibody to ETA (golden hamsters and guinea pigs); the possession of sensitive skin and various titers of antibody to ETA (humans and mice). 4) The incidence of ET producing strains of Staphylococcus aureus in various clinical specimens obtained from patients without SSSS was 12% (50 out of 418 strains) in our epidemiological investigation. The percentages of antibody to ETA in sera obtained from healthy males and females were 23% and 29%, respectively. Eventually, ET-producing strains of Staphylococcus aureus seem to be spread out wider than the microbiological result obtained from clinical specimens. 5) The mitogenic responses of lymphocytes isolated from patients with the first impetigo could be measured by using PHA, and the five-of them were in the low range, whereas lymphocytes from patients with recurrent impetigo were in the normal range on this survey. Maybe this results suggest the T lymphocyte functions of some patients with impetigo are deteriorated.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Acute glomerulonephritis and streptococcal skin lesions in Eskimo children.

Poststreptococcal acute glomerulonephritis often follows impetigo and can occur in epidemics. From 1975 through 1977, an epidemic of poststreptococcal acute glomerulonephritis occurred in Alaska. Fifty children required hospitalization, while 25 less seriously ill children were treated as outpatients. Sixty-seven percent of these 75 children had direct evidence of recent skin infections. Serotypes 49-14 and NT-14 were the most common streptococcal isolates. In villages in the epidemic area, approximately 15% of children had impetigo and more than 60% of lesions cultured were positive for group A streptococci. Impetigo rates in the epidemic area were similar to those found in nonepidemic areas. However, the introduction of the nephritogenic streptococcal serotypes not recently present in this population apparently led to the development of the epidemic.

Acute Disease↗

Assessment of Streptococcus pyogenes microcolony formation in infected skin by confocal laser scanning microscopy.

BACKGROUND: Streptococcus pyogenes and Staphylococcus aureus are often simultaneously detected from many cases of non-bullous impetigo with atopic dermatitis. OBJECTIVES: Using confocal laser scanning microscopy (CLSM), to investigate formation of S. pyogenes microcolonies in skin lesions. METHODS: The S. pyogenes cells in the stationary growth phase alone were strongly stained with fluorescein isothiocyanate-concanavalin A (FITC-ConA), and this staining was reduced by pretreatment with amylase. Although the components of sugars in glycocalyx produced by S. pyogenes cells are unknown, we suggested that the materials stained by FITC-ConA were consistent with the presence of ConA-reactive sugars in glycocalyx produced by S. pyogenes cells. RESULTS: S. pyogenes cells associated with streptococcal impetigo skin and croton-oil inflamed mouse skin formed microcolonies encircled by materials (glycocalyx) that stained strongly with FITC-ConA, and these findings were consistent with those in biofilms. In croton-oil inflamed mouse skin, polymorphonuclear leukocytes (PMNs) infiltrated to just below the epidermis in the cefdinir-treated group but only to the middle dermis in the cefdinir-non-treated group. In this case S. pyogenes and S. aureus cells formed separate microcolonies and existed independently in the outer walls of pustule lesions of streptococcal impetigo. CONCLUSION: In skin infections, S. pyogenes and S. aureus formed aggregates of microcolonies (similar to that in biofilms) encircled by glycocalyx, which can make the infection hard to eradicate using an antimicrobial agent alone. The effect of conventional antimicrobial agents against biofilm is mainly due to the increase of the invasion of PMNs into the biofilm.

Adolescent↗

Differential pathomechanisms of epidermal necrolytic blistering diseases.

Staphylococcal scalded skin syndrome (SSSS) results from the effect of exfoliative-toxins produced by staphylococcal strains. The disease affects predominantly children, and is rare in adults. We report two cases of the adult type of SSSS. Corticotherapy, chronic alcohol abuse and epilepsy-related immune changes might have been predisposing factors in these patients. The immunopathological characteristics of the inflammatory cell infiltrate in adults SSSS have not been thoroughly explored so far in the literature. Biopsies from 2 patients with bullous SSSS skin were studied by means of immunochemistry using a panel of 10 antibodies directed to FXIIIa, CD15, CD31, CD45R0, CD50, CD54, CD62E, CD95, CD106, and L1-protein, respectively. Cutaneous biopsies from related blistering diseases were compared. They included drug-induced toxic epidermal necrolysis (TEN), bullous impetigo and superficial pemphigus. A dense cell infiltrate composed of granulocytes (CD15+), macrophages (L1 protein+) and memory T cells (CD45R0+) and a strong expression of ICAM-3 (CD50) were present in the epidermis. CD95+ keratinocytes were lining the intraepidermal blisters. Type I dermal dendrocytes (Factor XIIIa+) were numerous and plump in the dermis. Bullous impetigo exhibited the same pattern of inflammatory cells, but with a lower density in type I dermal dendrocytes. TEN differed from SSSS by both the absence of CD15+ granulocytes and a stronger expression of the pro-apoptotic CD95 antigen in the epidermis. In superficial pemphigus, CD95 antigen was not expressed, and CD15+ granulocytes, CD45R0+ lymphocytes and L1 protein+ monocytes were much less numerous. It is concluded that the specific binding of SSSS-induced exotoxins to the desmosomes alters the keratinocyte metabolism leading to an inflammatory reaction followed by focal apoptosis. Our findings are in line with the concept that SSSS exotoxins might be superantigens. A common pathomechanism leading to epidermal destruction is likely operative in SSSS and bullous impetigo. The inflammatory cell composition in TEN and superficial pemphigus markedly differs from that in SSSS.

Female↗

Incidence and studies on antigenic specificities of antineutrophil-cytoplasmic autoantibodies (ANCA) in poststreptococcal glomerulonephritis.

Sera from 210 patients with Acute Poststreptococcal Glomerulonephritis (APSGN) and 14 patients with streptococcal impetigo without glomerular disease were tested for the presence of IgG-ANCA using an indirect immunofluorescence assay (IIF) on ethanol fixed normal human neutrophils. In the group of nephritic patients, ANCA were detected by IIF in 9% (18 out of 210 cases) in an atypical diffuse cytoplasmic pattern (a-ANCA) in 14 cases and in a (p-ANCA) perinuclear staining in the remaining 4 cases. Longitudinal studies performed on six IIF positive patients, showed persistence of the phenomenon for up to six months, without relationship with activity of disease. No patient with streptococcal impetigo showed positivity on the IIF assay. Positive sera were analyzed on ELISA plates for their IgG reactivity against specific purified ANCA antigens: Proteinase-3 (PR3), Myeloperoxidase (MPO). Cathepsin-G and Bactericidal/Permeability Increasing Protein (BPI). Anti-MPO antibodies were present in 4 cases (3 a-ANCA and 1 p-ANCA). No reactivity was identified against PR-3, BPI and Catepsin-G in any of the samples. The presence of ANCA was significantly associated with a more severe glomerular disease as assessed by the serum creatinine and the crescents formation. Further studies are required to identify other antigenic specificities of these autoantibodies. Their absence in the streptococcal impetigo control group might suggest that their presence in APSGN could play some pathogenic role in kidney disease.

Acute Disease↗

Role for a secreted cysteine proteinase in the establishment of host tissue tropism by group A streptococci.

Primary infection of the human host by group A streptococci (GAS) most often involves either the epidermis of the skin or the oropharyngeal mucosa. A humanized in vivo model for impetigo was used to investigate the basis for host tissue tropism among GAS. Disruption of the speB gene (encoding for a secreted cysteine proteinase) led to a loss of virulence for two impetigo-derived strains (M-types 33 and 53), as evidenced by a diminution in tissue damage and a lack of reproductive growth. The level of cysteine proteinase activity in overnight cultures was associated with the extent of gross pathological changes induced by strains displaying varied degrees of virulence in the impetigo model. Moreover, high levels of secreted cysteine proteinase activity correlated with a genetic marker for preferred tissue site of infection at the skin (emm pattern D). The addition of exogenous SpeB to a speB mutant (emm pattern D) or to an avirulent throat-like strain (emm pattern A) led to increased bacterial reproduction at the skin. The data provide both experimental and epidemiological evidence for a critical role of a secreted bacterial protease in promoting host tissue-specific infection.

Bacterial Proteins↗

Skin and soft tissue infection.

Abstract. Normal skin is heavily colonized by bacterial flora. The most common are the various nonpathogenic gram-positive bacteria such as Staphylococcus epidermidis (coagulase-negative). Skin and soft tissue infections are usually caused by Staphylococcus aureus (S. aureus) and Streptococcus pyogenes. This article discusses common and some not so common bacterial skin infections, including impetigo, folliculitis, furncles and carbuncles, cellulitis and erysipelas, gangrenous cellulitis, staphylococcal scalded skin syndrome and scarlet fever. Impetigo and ecthyma are common bacterial infections of the skin commonly caused by S. aureus and / or Group A streptoccus. In mild and localized impetigo topical antibiotics whereas in widespread or severe one and in ecthyma systemic antibiotics like, cloxacillin, erythromycin, azithromycin or cephalexin should be used. Folliculitis, furunculosis and carbuncle are folliculocentric infections caused by S. aureus involving the variable depth and extent of the follicle(s) and surrounding tissue. These conditions can be treated with topical or systemic antibiotics like cloxacillin, cephalexin, erythromycin, amoxicillin/clavulanic acid or vancomycin. Staphylococcal scalded skin syndrome is a toxin mediated exfoliative dermatosis caused by S. aureus of phase group II. Intravenous penicillinase-resistant anti-staphylococcal antibiotics like methicillin, cloxacillin, cephalosporin or erythromycin are required. Erysipelas and cellulitis are acute infections of dermal and subcutaneous tissues caused most frequently by Group A beta-hemolytic streptococci (erysipelas) or S. aureus requiring systemic antibiotics like oral or intravenous penicillin, erythromycin, cephalexin, cloxacillin, vacomycin, minocycline or ciprofloxacin depending upon the severity, suspected causative organism and culture/sensitivity results. Gangrenous cellulitis is characterized by infection with necrosis of skin and underlying subcutaneous tissue due to various pathogens occurring at different site. Ampicillin, gentamicin, and either metronidazole or clindamycin intravenously in standard doses are recommended for the treatment.

Cellulitis↗

Mupirocin: a topical antibiotic with a unique structure and mechanism of action.

The chemistry, mechanism of action, antimicrobial activity, pharmacokinetics, clinical efficacy, adverse effects, dosage, and administration of mupirocin are reviewed. Mupirocin, formerly termed pseudomonic acid A, is a topical antibiotic under investigation for the treatment of impetigo and other superficial primary and secondary skin infections. Mupirocin (Bactroban, Beecham Laboratories) is currently formulated as a 2% ointment in a water-miscible polyethylene glycol base. The drug is a unique antimicrobial agent because of its structure and mechanism of action. Mupirocin apparently exerts its antimicrobial activity by reversibly inhibiting isoleucyl-transfer RNA, thereby inhibiting bacterial protein and RNA synthesis. Mupirocin has excellent in vitro activity against staphylococci and most streptococci but less activity against other gram-positive and gram-negative bacteria. The drug will only be used topically because of its rapid and extensive systemic metabolism. Several controlled clinical trials documented that mupirocin was significantly better than the polyethylene glycol vehicle alone or ampicillin and as effective as cloxacillin, dicloxacillin, or erythromycin in producing clinical and bacteriological cures in patients with impetigo and wound infections caused by gram-positive pathogens. Limited studies suggest that mupirocin may also have a role in eradicating nasal carriage of staphylococci. Reported adverse effects are local and may be related to the polyethylene glycol vehicle base. Mupirocin should be useful for treating patients with impetigo and wound infections caused by Staphylococcus aureus. However, additional controlled, comparative clinical studies are needed to identify the role of mupirocin in treating other primary and secondary skin infections and for eliminating nasal carriage of staphylococci.

Administration, Topical↗

Streptococcal erythrogenic toxin spe A gene detection by polymerase chain reaction in strains isolated in Albania.

The presence of gene encoding erythrogenic toxin type A (spe A) was determined by the polymerase chain reaction (PCR) to target specific sequences in 72 strains of Streptococcus pyogenes representative T type strains, which were associated with scarlet fever, impetigo, tonsillitis, isolated between the years 1980-1982 and in 1995 by carriers. Isolates showed statistically significant differences in the presence of spe A. With scarlet fever the strains had a 22.22% association, with impetigo had a 8.33% association. With tonsillitis' and with carriers had a low association, 5.55% and 6.9% respectively. The analysis of the data indicated that strains with certain T type surface antigens showed a higher (such as T-1, T-2, T-5) or lower (such as T-4, T-13, T-27) tendency to contain the spe A gene were more likely to be associated with scarlet fever and impetigo than with other types of diseases.

Albania↗

A genetic-based evaluation of the principal tissue reservoir for group A streptococci isolated from normally sterile sites.

The primary sites of infection and principal reservoirs for transmission of group A streptococci are the nasopharyngeal mucosa and the impetigo lesion. However, pharyngitis and impetigo are rarely observed prior to invasive disease, and, thus, the origin of invasive strains is largely unknown. As part of an active surveillance program, group A streptococci were obtained from normally sterile tissue sites of Connecticut residents during a 6-month period. Organisms were analyzed for genetic markers that distinguish between strains that use the nasopharynx versus an impetiginous lesion as their primary site for infection. The nasopharyngeal marker was observed for most sterile-site isolates, suggesting that the upper respiratory tract is the principal reservoir from which organisms causing invasive disease are disseminated. Genotypic analyses of sterile-site isolates support the view that additional factors, aside from a recent emergence of a few virulent clones, are important contributors to invasive group A streptococcal disease.

Base Sequence↗

A human IgG receptor of group A streptococci is associated with tissue site of infection and streptococcal class.

The distribution of receptors for immunoglobulins of several different isotypes was examined for group A streptococcal isolates derived from skin and nasopharyngeal sites. Although human IgG-Fc receptor activity was a variable property of group A streptococci, found among 61% of all isolates tested, it was largely restricted to well-defined subpopulations. Human IgG-binding activity was observed among nearly all impetigo isolates examined. In addition, the expression of the class II M protein molecule (one of two broad antigenic classes of the major virulence factor) and opacity factor (a lipoproteinase) was almost invariably accompanied by human IgG binding, regardless of tissue site of infection. In contrast to class I impetigo isolates, class I nasopharyngeal isolates were relatively devoid of human IgG-binding activity. The data suggest that the presence or absence of human IgG-binding activity correlates with certain diseases caused by group A streptococci.

Animals↗

Lipolytic activity of Staphylococcus aureus strains from disseminated and localized infections.

Lipase production of 425 S. aureus strains isolated from patients with different clinical diagnoses and healthy carriers were measured by a specific method, using emulsified trioleoylglycerol substrate. Strains isolated from patients with septicemia showed significantly higher lipase activity than osteomyelitis strains (p = 0.011), impetigo strains (p = 0.002) and strains isolated from healthy relatives of patients with recurrent furunculosis (p = 0.019). Recurrent furunculosis and pyomyositis strains had significantly higher (p = 0.002 and 0.032, respectively) lipase activity than septicemia strains. S. aureus strains isolated from patients with a significant antibody response in an antilipase ELISA did not show a higher lipase activity in culture supernatants than strains from patients without a significant antibody response. The lipase activity was significantly higher in strains isolated from deep or subcutaneous infections, i.e., septicemia, pyomyositis, osteomyelitis, aerobic and anaerobic furunculosis, than in strains from superficial infections, i.e. impetigo, or from nasal mucosa.

Furunculosis↗

Susceptibility of Staphylococcus aureus to cefaclor and cephalothin: laboratory and clinical studies.

In vitro susceptibility tests of 201 strains of Staphylococcus aureus by agar dilution revealed 90% to be susceptible to 8 mug or less of cefaclor per ml. Strains from hospitalized children and adults were more often resistant than those from patients with bullous impetigo. Cephalothin was more active than cefaclor against all strains tested. Results with disk tests, including those strains examined from the clinical investigation, revealed some discrepancies in identifying strains more resistant to cefaclor. In clinical studies, cefaclor proved quite effective for the treatment of bullous impetigo. Of 73 patients, 90% were cured and 7% improved after completing 5 or more days of treatment. Prompt improvement was noted among most patients seen 3 to 5 days after treatment was begun. One patient experienced mild diarrhea. There were no other adverse or toxic manifestations attributable to therapy.

Adolescent↗

Epidemiological analysis of non-M-typeable group A Streptococcus isolates from a Thai population in northern Thailand.

Infection with group A streptococci (GAS) can lead to the development of severe postinfectious sequelae such as rheumatic fever (RF). In Thailand, RF and rheumatic heart disease (RHD) remain important health problems. More than 80% of GAS circulating in this population are non-M antigen typeable by conventional M serotyping methods. In this study, we determine the M protein sequence types of GAS isolates found in northern Thailand. The emm genes from 53 GAS isolates, collected between 1985 and 1995 from individuals with pharyngitis, impetigo, acute RF (ARF), RHD, or meningitis as well as from individuals without infections, were amplified by PCR and sequenced. Thirteen new sequence types that did not show homology to previously published sequences were characterized. Six of these sequence types could be isolated from both skin and throat sites of impetigo and pharyngitis/ARF patients, respectively. In many cases we could not specifically differentiate skin strains or throat strains that could be associated with ARF or acute glomerulonephritis. Antigenic variations in the emm gene of the isolates investigated, compared to published M protein sequences, were predominantly due to point mutations, small deletions, and insertions in the hypervariable region. One group of isolates with homology to M44 exhibited corrected frameshift mutations. A new M type isolated from an RHD patient exhibited nucleotide sequence corresponding to the N terminus of M58 and the C terminus of M25, suggesting that recombination between the two types may have occurred. This study provided epidemiological data relating to GAS endemic to northern Thailand which could be useful for identification of vaccine candidates in a specific region of endemicity.

Antigens, Bacterial↗

A Panton-Valentine leucocidin (PVL)-positive community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strain, another such strain carrying a multiple-drug resistance plasmid, and other more-typical PVL-negative MRSA strains found in Japan.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was collected from children with bullous impetigo in 2003 and 2004. One strain collected in 2003 was Panton-Valentine leucocidin (PVL) positive. In 2004, a multiple-drug-resistant PVL(+) CA-MRSA strain was isolated from an athlete with a cutaneous abscess. These strains were analyzed by multilocus sequence typing, spa typing, agr typing, coagulase typing, staphylococcal cassette chromosome mec (SCCmec) typing, PCR assay for 30 virulence genes, drug susceptibility testing, pulsed-field gel electrophoresis, and for plasmids. The two Japanese PVL(+) CA-MRSA strains belonged to the globally extant ("pandemic") sequence type 30 (ST30) with SCCmec IV. A transmissible, multiple-drug resistance plasmid emerged in such ST30 strains. The PVL(-) CA-MRSA strains ("domestic" CA-MRSA) accumulated for bullous impetigo, exhibiting new genotypes. Hospital-acquired MRSA of ST91 (but not pandemic ST5) shared common features with the PVL(-) CA-MRSA strain.

Adolescent↗

Common bacterial skin infections.

Family physicians frequently treat bacterial skin infections in the office and in the hospital. Common skin infections include cellulitis, erysipelas, impetigo, folliculitis, and furuncles and carbuncles. Cellulitis is an infection of the dermis and subcutaneous tissue that has poorly demarcated borders and is usually caused by Streptococcus or Staphylococcus species. Erysipelas is a superficial form of cellulitis with sharply demarcated borders and is caused almost exclusively by Streptococcus. Impetigo is also caused by Streptococcus or Staphylococcus and can lead to lifting of the stratum corneum resulting in the commonly seen bullous effect. Folliculitis is an inflammation of the hair follicles. When the infection is bacterial rather than mechanical in nature, it is most commonly caused by Staphylococcus. If the infection of the follicle is deeper and involves more follicles, it moves into the furuncle and carbuncle stages and usually requires incision and drainage. All of these infections are typically diagnosed by clinical presentation and treated empirically. If antibiotics are required, one that is active against gram-positive organisms such as penicillinase-resistant penicillins, cephalosporins, macrolides, or fluoroquinolones should be chosen. Children, patients who have diabetes, or patients who have immunodeficiencies are more susceptible to gram-negative infections and may require treatment with a second- or third-generation cephalosporin.

Cellulitis↗