Streptococci isolated from various skin lesions: the interaction with Staphylococcus aureus strains

Doxycycline versus cephalexin treatment of presumed streptococcal skin and soft tissue infection among adults presenting to the emergency department

Among 100 propensity score-matched emergency department patients receiving ≤14 days doxycycline versus cephalexin monotherapy for outpatient treatment of nonpurulent (presumed streptococcal) skin and soft tissue infection, a low rate of 14-day clinical failure was observed [6% each group; odds ratio (OR), 1.34 (0.21-8.69); P = 0.745], defined as hospital admission, i.v. antibiotic therapy, or change in oral antibiotic. Doxycycline may represent a reasonable therapeutic alternative for this indication in regions with low tetracycline resistance.

Guía de práctica clínica para el diagnóstico y manejo de las infecciones de piel y tejidos blandos en Colombia

Las infecciones de piel y tejidos blandos (IPTB) representan la tercera causa de consulta por enfermedad infecciosas a los servicios médicos, después de las infecciones respiratorias y urinarias. Se presenta una guía de práctica clínica (GPC) con 38 recomendaciones basadas en la evidencia, graduadas bajo el sistema SIGN, para el diagnóstico y tratamiento de pacientes adultos con IPTB en el contexto colombiano, posterior a un proceso de adaptación de GPC publicadas y la búsqueda sistemática y síntesis de literatura para la actualización de la evidencia científica. Además, se realizó un consenso de expertos para la evaluación de las potenciales barreras para la implementación de las recomendaciones y la evaluación del grado de recomendación en el contexto local.

Impetigo - review

Impetigo is a common cutaneous infection that is especially prevalent in children. Historically, impetigo is caused by either group A β-hemolytic streptococci or Staphylococcus aureus. Currently, the most frequently isolated pathogen is S. aureus. This article discusses the microbiologic and virulence factors of group A β-hemolytic streptococci and Staphylococcus aureus, clinical characteristics, complications, as well as the approach to diagnosis and management of impetigo. Topical agents for impetigo therapy are reviewed.

Bacterial skin colonization and infections in patients with atopic dermatitis

Atopic Dermatitis is a chronic inflammatory skin disease that affects a large number of children and adults. The disease results from an interaction between genetic predisposition, host environment, skin barrier defects, and immunological factors. A major aggravating factor associated with Atopic Dermatitis is the presence of microorganisms on the patient's skin surface. Staphylococcus aureus and Streptococcus pyogenes, for instance, can exacerbate chronic skin inflammation. As a result, antimicrobials have often been prescribed to control the acute phase of the disease. However, increased bacterial resistance to antimicrobial agents has made it difficult for dermatologists to prescribe appropriate medication. In the presence of disseminated dermatitis with secondary infection, systemic antibiotics need to be prescribed; however, treatment should be individualized, in an attempt to find the most effective antibiotic with fewer side effects. Also, the medication should be used for as short as possible in order to minimize bacterial resistance.

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.

Impetigo neonatorum associated with late onset group B streptococcal meningitis

We present a case of nonbullous impetigo neonatorum associated with late onset group B streptococcal meningitis in a 12-day-old infant. Both skin lesions and meningitis resolved with antibiotic therapy. This is the first reported case of meningitis during the course of this skin disease.

Predominant Staphylococcus aureus isolated from various skin diseases

We examined predominant Staphylococcus aureus isolated from lesions of various skin diseases, and during the past 3 years, 113 methicillin-sensitive and 31 methicillin-resistant S. aureus have been isolated. The predominant species isolated from almost all of the primary bacteriological cultures was S. aureus. The skin diseases from which cultures were most frequently prepared were atopic dermatitis, followed by ulcers. S. aureus was the predominant species in two-thirds or more of cases of all of the different skin diseases examined. The predominant species identified, other than S. aureus, included Streptococcus species and Pseudomonas aeruginosa. Evaluation of the predominance of S. aureus is important to the determination of the severity of skin lesions and, if needed, appropriate antimicrobial therapy.

Characteristics in adherence of streptococci and Staphylococcus aureus isolated from various infective skin lesions: serum IgA decreases adherence of Streptococcus pyogenes but not Staphylococcus aureus

We characterized adherence of streptococci and Staphylococcus aureus strains isolated from various infective skin lesions in terms of hydrophobicity, negative charge, tube adherence, slime production, and influence on adherence to coverslips by plasma and serum immunoglobulins. High hydrophobicity was more frequently observed in Streptococcus pyogenes strains than in Streptococcus agalactiae strains (P < 0.01) and S. aureus strains (P < 0.001) and slime production was more frequently observed in S. agalactiae strains than in S. pyogenes strains (P < 0.05). Serum IgA decreased adherence to coverslips of S. pyogenes strains but not that of S. aureus strains.