Ecthyma gangrenosum with a coinfection of methicillin-sensitive staphylococcus aureus and streptococcus pyogenes: a case report

Introduction: Ecthyma gangrenosum (EG) is a cutaneous infection characterized by gangrenous ulcers with erythematous borders seen in immunocompromised as well as immunocompetent individuals. Although Pseudomonas aeruginosa is the commonest pathogen isolated, several other bacteria and fungi contribute to the pathogenesis of EG. Identification of the microorganism is very essential to initiate early empirical antimicrobial therapy. Case presentation: We present a case report of a 13-year-old boy with multiple recurrent ulcerative lesions in both lower extremities for the past 1 year. His blood parameters showed signs of inflammation but was negative for aerobic blood culture, suggesting absence of underlying bacteraemia. There were no features of immunosuppression. On examination of pus sample, Methicillin Sensitive Staphylococcus aureus and Streptococcus pyogenes were isolated from the ulcerative lesions. Amoxicillin- Clavulanate and Doxycycline was advised for 2 weeks along with surgical debridement of the lesion followed by aseptic dressing. Patient showed complete resolution after 2 weeks. Discussion: Staphylococcus aureus and Streptococcus pyogenes were the causative agents in this case, suggesting a polymicrobial association of EG besides Pseudomonas aeruginosa. Underlying bacteraemia or any other immunodeficiency is usually seen in a case of EG, however there are cases reported where cutaneous manifestations show predominance. Conclusion: A prompt diagnosis of EG is essential because there are instances when it has proven to be fatal. Ruling out any immunodeficiency disorders and underlying bacteraemia is of vital importance. Administration of proper antibiotic coverage (gram positive or gram negative) along with debridement and regular dressing can help in limiting the spread of infections and thus improving patient outcome

A novel method for early detection of MIC value – Broth dilution using indicator solution versus agar dilution: an original article

Introduction: The adequate protocol for treatment of an infection is often determined on the basis of the minimum inhibitory concentration (MIC) of the causative organism. Traditional methods (agar dilution, microbroth dilution, and gradient diffusion) are labour intensive and time consuming (they are usually take over 48 hours to report the results). On the other hand, automated systems (VITEK™, Phoenix™, MicroScan WalkAway™) and rapid methods of MIC detection (using dielectrophoresis (DEP), magnetic bead rotation sensors and microfluidic incubation) require expensive instruments. This study is aimed to develop a rapid MIC detection method with the ability to applied to a resource limited setting. Methods: Agar dilution method and a novel broth dilution method (containing indicator solution) were simultaneously performed using amikacin, ceftriaxone, piperacillin-tazobactam, imipenem, cefoxitin and azithromycin. Results: Isolates of Escherichia coli, Enterobacter spp, Klebsiella spp, Staphylococcus aureus, Proteus mirabilis, Acinetobacter spp and Pseudomonas spp were used. The MIC values for Enterobacteriaceae and S. aureus isolates for each antibiotic were obtained within 4 to 5 hours by a novel broth dilution method. The obtained MIC values were corresponded with the MIC shown on the following day by agar dilution method. Conclusion: Broth dilution method with indicator solution is effective in rapid determination of the MIC for cephalosporins, penicillin, carbapenems, cephamycin, aminoglycosides and macrolides for most isolates of Enterobacteriaceae and S. aureus. Unfortunately this method did not work for the non-fermenter group of organisms like Pseudomonas spp and Acinetobacter spp, as their results could not be obtained before 24 hours. The method is time saving, relatively inexpensive and is applicable to resource limited settings

A novel method for early detection of MIC value – Broth dilution using indicator solution versus agar dilution: an original article

Introduction: The adequate protocol for treatment of an infection is often determined on the basis of the minimum inhibitory concentration (MIC) of the causative organism. Traditional methods (agar dilution, microbroth dilution, and gradient diffusion) are labour intensive and time consuming (they are usually take over 48 hours to report the results). On the other hand, automated systems (VITEK™, Phoenix™, MicroScan WalkAway™) and rapid methods of MIC detection (using dielectrophoresis (DEP), magnetic bead rotation sensors and microfluidic incubation) require expensive instruments. This study is aimed to develop a rapid MIC detection method with the ability to applied to a resource limited setting. Methods: Agar dilution method and a novel broth dilution method (containing indicator solution) were simultaneously performed using amikacin, ceftriaxone, piperacillin-tazobactam, imipenem, cefoxitin and azithromycin. Results: Isolates of Escherichia coli, Enterobacter spp, Klebsiella spp, Staphylococcus aureus, Proteus mirabilis, Acinetobacter spp and Pseudomonas spp were used. The MIC values for Enterobacteriaceae and S. aureus isolates for each antibiotic were obtained within 4 to 5 hours by a novel broth dilution method. The obtained MIC values were corresponded with the MIC shown on the following day by agar dilution method. Conclusion: Broth dilution method with indicator solution is effective in rapid determination of the MIC for cephalosporins, penicillin, carbapenems, cephamycin, aminoglycosides and macrolides for most isolates of Enterobacteriaceae and S. aureus. Unfortunately this method did not work for the non-fermenter group of organisms like Pseudomonas spp and Acinetobacter spp, as their results could not be obtained before 24 hours. The method is time saving, relatively inexpensive and is applicable to resource limited settings.</jats:p