Staphylococcus aureus antibiotic susceptibility patterns in pediatric atopic dermatitis.

BACKGROUND/OBJECTIVES: Staphylococcus aureus is the most prevalent bacterial pathogen in atopic dermatitis (AD) patients presenting with skin infections. Despite the known association between S aureus and AD, guidance on empiric antibiotics for skin infections in pediatric AD patients is limited. METHODS: We conducted a retrospective study over a five-year period to characterize the S aureus strains recovered from pediatric AD patients with clinically apparent bacterial skin infections treated in an academic medical center. We assessed patient demographics and dilute bleach bath usage to determine whether these factors were correlated with methicillin resistance. Culture results from our AD cohort were also compared to those from pediatric patients presenting to the Saint Louis Children's Hospital emergency department (ED) with S aureus skin abscesses from 2013 to 2015. RESULTS: Methicillin-sensitive S aureus (MSSA) was more prevalent (77.8%) than methicillin-resistant S aureus (MRSA) (22.2%). There was no correlation between MRSA and age, sex, race, or dilute bleach bath use. In comparison with pediatric patients presenting to the ED, AD patients had lower rates of MSSA susceptibility to doxycycline and MRSA susceptibility to trimethoprim-sulfamethoxazole (TMP-SMX). CONCLUSIONS: First-generation cephalosporins remain appropriate empiric therapy for most pediatric AD patients. In patients with a history of MRSA, empiric doxycycline or TMP-SMX could be considered, given their high MRSA susceptibility rates.

Antimicrobial activity of Nigella sativa L. seed oil against multi-drug resistant Staphylococcus aureus isolated from diabetic wounds.

Microbial resistance to existing antibiotics has led to an increase in the use of medicinal plants that show beneficial effects for various infectious diseases. The study evaluates the susceptibility of multidrug resistant Staphylococcus aureus to Nigella sativa oil. Staphylococcus aureus was isolated from 34 diabetic patient's wounds attending the Renaissance hospital, Nsukka, Southeast Nigeria. The isolates were characterized and identified using standard microbiological techniques. Isolates were cultured and a comparative In vitro antibiotic susceptibility test was carried out using the disk diffusion method. Of the 34 samples collected, 19(56%) showed multidrug resistance to the commonly used antibiotics. Nigella sativa oil was then studied for antibacterial activity against these multidrug resistant isolates of Staphylococcus aureus in varying concentration by well diffusion method. The oil showed pronounced dose dependent antibacterial activity against the isolates. Out of 19 isolates, 8(42%) were sensitive to undiluted oil sample; 4(21%) of these showed sensitivity at 200 mg/ml, 400 mg/ml and 800 mg/ml respectively. Eleven (58%) of the isolates were completely resistant to all the oil concentrations. The present study, reports the isolation of multi-drug resistant S. aureus from diabetic wounds and that more than half of isolates were susceptible to different concentrations N. sativa oil.

A retrospective analysis of skin bacterial colonisation, susceptibility and resistance in atopic dermatitis and impetigo patients.

Atopic dermatitis (AD) and impetigo are skin conditions where bacterial colonisation and infection, especially with Staphylococcus aureus play an important role. We compared skin bacterial population, resistance patterns and choice of antimicrobial agents in patients diagnosed with AD and impetigo during 2005 and 2011 in our department. Number of positive cultures in the AD group were 40 and 53 in 2005 and 2011, with S. aureus found in 97.5% and 100%, respectively. Differences in resistance were marginal. In impetigo, S. aureus was found in all 70 patients in 2005 and all 40 patients in 2011. Antibiotic resistance to specifically fusidic acid was more common in 2005 impetigo patients (22.8%) versus 2011 (5%) (p = 0.078). The most commonly used oral antimicrobial was cefadroxil (in 57.5% and 52.8% of AD and 58.6% and 35% of impetigo patients in 2005 and 2011, respectively). Our observations confirm the high prevalence of S. aureus in both diseases and, interestingly, show a declining resistance trend in impetigo.

A tragic case of atopic eczema: malnutrition and infections despite multivitamins and supplements.

Eczema is a common childhood atopic condition and treatment is with emollients, topical corticosteroids and avoidance of possible triggers. S. aurues colonization is a common complication. During exacerbation, intensification of treatment is needed to relieve the child from the miserable symptoms of pruritus and sleep disturbance. Systemic antibiotics against S. aureus may be required. We report an infant with eczema who presented with a generalised rash, cardiac arrest and septic shock. Kwashiorkor-like protein energy malnutrition was noted presumably due to deviated dietary practice. Childhood eczema is an eminently treatable atopic disease. Extreme alternative therapy seems not to be efficacious and may even be associated with grave sequelae.

Prevalence, severity, and treatment of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft tissue infections in 10 medical clinics in Texas: a South Texas Ambulatory Research Network (STARNet) study.

OBJECTIVES: Quantify the prevalence, measure the severity, and describe treatment patterns in patients who present to medical clinics in Texas with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft-tissue infections (SSTI). METHODS: Ten primary care clinics participated in this prospective, community-based study. Clinicians consented patients and collected clinical information, pictures, and wound swabs; data were processed centrally. MRSASelect™ was used for identification. Susceptibilities were determined via Etest®. RESULTS: Overall, 73 of 119 (61%) patients presenting with SSTIs meeting eligibility requirements had CA-MRSA. Among these, 49% were male, 79% were Hispanic, and 30% had diabetes. Half (56%) of the lesions were ≥ 5 cm in diameter. Most patients had abscesses (82%) and many reported pain scores of ≥ 7 of 10 (67%). Many presented with erythema (85%) or drainage (56%). Most received incision and drainage plus an antibiotic (64%). Antibiotic monotherapy was frequently prescribed: trimethoprim-sulfamethoxazole (TMP-SMX) (78%), clindamycin (4%), doxycycline (2%), and mupirocin (2%). The rest received TMP-SMX in combination with other antibiotics. TMP-SMX was frequently administered as one double-strength tablet twice daily. Isolates were 93% susceptible to clindamycin and 100% susceptible to TMP-SMX, doxycycline, vancomycin, and linezolid. CONCLUSIONS: We report a predominance of CA-MRSA SSTIs, favorable antibiotic susceptibilities, and frequent use of TMP-SMX in primary care clinics.

Antibiotic selection for purulent skin and soft-tissue infections in ambulatory care: a decision-analytic approach.

OBJECTIVE: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has caused a nationwide epidemic of skin and soft-tissue infections in ambulatory pediatrics. Antibiotic treatment recommendations suggest incorporating local epidemiology for the prevalence of CA-MRSA. We sought to identify the antibiotic strategy with the highest probability of activity and to identify threshold values for epidemiologic variables including bacterial prevalence and antibiotic resistance. METHODS: We used decision analysis to evaluate 3 empiric antibiotic strategies: clindamycin, trimethoprim/sulfamethoxazole (T/S), and cephalexin. We calculated the probability of activity against the bacteria causing the infection (CA-MRSA, methicillin-sensitive S. aureus and group A Streptococcus [GAS]) by incorporating estimates of prevalence and antibiotic resistance to determine the optimal strategy. Sensitivity analysis was used to identify thresholds for prevalence and antibiotic resistance where 2 strategies were equal. RESULTS: Clindamycin (0.95) and T/S (0.89) had substantially higher probability of activity than cephalexin (0.28) using baseline estimates for bacterial prevalence and antibiotic resistance. Cephalexin was the optimal antibiotic only when CA-MRSA prevalence was <10%. The probability of activity for clindamycin and T/S was highly sensitive to changes in the values for bacterial prevalence (both CA-MRSA and GAS) and CA-MRSA resistance to clindamycin. CONCLUSIONS: Empiric treatment of skin and soft-tissue infections with either clindamycin or T/S maximizes the probability that the antibiotic will be active when CA-MRSA prevalence is >10%. Deciding between T/S and clindamycin requires consideration of antibiotic resistance and prevalence of GAS. This model can be customized to local communities and illustrates the importance of ongoing epidemiologic surveillance in primary care settings.

Epidemiology, clinical manifestations, and treatment options for skin and soft tissue infection caused by community-acquired methicillin-resistant Staphylococcus aureus.

PURPOSE: This article reviews the evolving epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and the appropriate outpatient management of CA-MRSA skin and soft tissue infection. Further, the paper will provide the basis upon which an individualized patient educational plan may be developed. DATA SOURCES: To complete this review, a search of English language publications was conducted through Medline and CINAHL databases (1966-2006). CONCLUSIONS: The epidemiology of CA-MRSA is becoming increasingly complex. Research that addresses the impact of this organism in high-risk populations and within families is urgently needed. IMPLICATIONS FOR PRACTICE: Nurse practitioners must remain informed of the epidemiology of common and emerging drug-resistant organisms in their patient populations.

Community-onset methicillin-resistant Staphylococcus aureus skin and soft-tissue infections: impact of antimicrobial therapy on outcome.

BACKGROUND: Conflicting data exist on the role of antimicrobial therapy for the treatment of uncomplicated community-onset methicillin-resistant Staphylococcus aureus (MRSA) skin and soft-tissue infections (SSTIs). METHODS: We performed a retrospective cohort study of 492 adult patients with 531 independent episodes of community-onset MRSA SSTIs, which consisted of abscesses, furuncles/carbuncles, and cellulitis, at 2 tertiary care medical centers. The purpose of the study was to determine the impact of active antimicrobial therapy (i.e., the use of an agent to which the organism is susceptible) and other potential risk factors on the outcome for patients with uncomplicated community-onset MRSA SSTIs. Treatment failure was the primary outcome of interest and was defined as worsening signs of infection associated with microbiological and/or therapeutic indicators of an unsuccessful outcome. Bivariate analyses and logistic regression analyses were preformed to determine predictors of treatment failure. RESULTS: An incision and drainage procedure was performed for the majority of patients. Treatment failure occurred in 45 (8%) of 531 episodes of community-onset MRSA SSTI. Therapy was successful for 296 (95%) of 312 patients who received an active antibiotic, compared with 190 (87%) of 219 of those who did not (P=.001 in bivariate analysis). Use of an inactive antimicrobial agent was an independent predictor of treatment failure on logistic regression analysis (adjusted odds ratio, 2.80; 95% confidence interval, 1.26-6.22; P=.01). CONCLUSIONS: Our findings suggest that certain patients with SSTIs that are likely caused by MRSA would benefit from treatment with an antimicrobial agent with activity against this organism.

[Bacterial colonization of chronic wounds. Studies on outpatients in a university dermatology clinic with special consideration of ORSA]. / Bakterielle Kolonisation chronischer Wunden. Untersuchungen in einer universitären dermatologischen Wundambulanz unter besonderer Berücksichtigung von ORSA.

In this retrospective investigation, we documented the bacterial colonization of 79 patients with chronic wounds, who had been treated between January 2002 and May 2003 in an outpatient wound healing clinic of a university dermatology program. We isolated 106 facultative pathogenic bacterial strains of which 56 were Staphylococcus aureus, 19 Pseudomonas aeruginosa, 11 Escherichia coli, 4 Proteus mirabilis, 4 Enterobacter cloacae, 2 Serratia marcescens, 2 Streptococcus group G und 8 further species. 68 of these bacterial strains were gram-positive and 46 gram-negative. Moreover we identified one patient with Candida parapsilosis. Therefore, 70.8% of all patients showed Staphylococcus aureus in their chronic wounds. Determination of the specific resistances showed 17 patients to be colonized with oxacillin- resistant Staphylococcus aureus (ORSA) strain; this corresponds to 21.5% of all patients. Consequently, 30.4% of all Staphylococcus aureus isolates were ORSA strains. All of the ORSA isolates were sensitive to vancomycin. Sensitivity to tetracycline was documented in 15, to amikacin in 13, to clindamycin in 7, to gentamicin and erythromycin in 6 of the ORSA-positive patients. In the case of trimethoprim/sulfamethoxazole, 10 were sensitive and 3 were intermediate in sensitivity. Beside the obligate resistance to oxacillin, penicillin G, ampicillin, cefuroxime and imipenem, none of the ORSA was sensitive to ofloxacin. The results of our investigations demonstrate the actual spectrum of bacterial colonization in chronic wounds of patients in an university dermatologic wound clinic and underline the growing problem of ORSA.