The clinical management of cesarean section-acquired Mycobacterium abscessus surgical site infections

Introduction: Rapidly growing mycobacteria (RGM) can cause a broad spectrum of both community and healthcare-associated infections in humans. The aim of this study was to report the clinical management and outcomes of successive patients following cesarean delivery with healthcare-associated surgical site infections (SSIs) caused by RGM. Methodology: Patients who were admitted to Chung Shan Medical University Hospital, Taichung, Taiwan, between September 2006 and July 2008, and who developed SSIs following cesarean delivery at an obstetrics hospital and were then referred to our hospital, were enrolled. Demographic characteristics of the patients and clinical isolates were obtained retrospectively and an environmental investigation was performed. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the hsp65gene and pulsed-field gel electrophoresis (PFGE) of large genomic DNA restriction fragments were applied to differentiate Mycobacterium species. Results: Seventeen patients were diagnosed with RGM infections by microbiology and/or histopathology. Mycobacterial isolates by PCR-RFLP analysis from 15 patients revealed Mycobacterium abscessus (M. abscessus) and M. lentiflavum. Most of the patients received surgical debridement and combination antimicrobial therapy and were eventually cured. Conclusions: Our study demonstrates the potential that RGM infections have in causing healthcare-associated SSIs. Surgery plus prolonged combination antimicrobial therapy seemed to be an effective option for the management of M. abscessus infections.

Evaluation of a PCR melting profile method for intraspecies differentiation of Trichophyton rubrum and Trichophyton interdigitale

In order to identify the source of infections caused by dermatophytes, as well as the pathogen transmission pathway, there is a need to determine methods that allow detailed genetic differentiation of the strains within the dermatophyte genera. In this work, a PCR melting profile (PCR-MP) technique based on the ligation of adaptors and the difference in melting temperatures of DNA restriction fragments was used for the first time for intraspecies genotyping of dermatophytes. Clinical isolates and reference strains of dermatophytes isolated from skin, scalp, toenails and fingernails were used for this study. PCR-MP and random amplification of polymorphic DNA (RAPD) were used to type 11 isolates of Trichophyton rubrum, 40 isolates of Trichophyton interdigitale and 14 isolates of Microsporum canis. The results distinguished five types (containing one subtype) characteristic for T. rubrum and seven types characteristic for T. interdigitale using the PCR-MP technique. Analysis conducted using RAPD revealed five types for T. rubrum and four types for T. interdigitale isolates. No differentiation was observed for the M. canis isolates with either method. These results demonstrate that PCR-MP is a reliable method for the differentiation of T. rubrum and T. interdigitale strains and yields a discriminatory power that is at least equal to that of RAPD.

Systematics of the Rubus fruticosus aggregate (Rosaceae) and other exotic Rubus taxa in Australia

Exotic Rubus taxa in Australia have been revised following consultation with European and North American experts in Rubus, allied with studies of variation in patterns of DNA restriction fragments and morphology. Many of these taxa have names that are applied for the first time in Australia (prefaced with a †). The major focus of the work was the Rubus fruticosus L. aggregate and taxa of this aggregate covered here are R. anglocandicans A. Newton, R. cissburiensis W.C. Barton & Ridd., †R. echinatus Lindl., †R. erythrops Edees & A. Newton, R. laciniatus Willd., R. leightonii Lees ex Leight. †R. leucostachys Schleich. ex Sm., †R. phaeocarpus W.C.R. Watson, R. polyanthemus Lindeb., †R. riddelsdellii Rilstone, †R. rubritinctus W.C.R. Watson, R. ulmifolius Schott (including R. ulmifolius var. ulmifolius and †R. ulmifolius var. anoplothyrsus Sudre), and R. vestitus Weihe, along with two undescribed taxa, Rubus sp. Scott Creek (D.E. Symon 16504) and Rubus sp. Tasmania (J.R. Hosking 1551). Other naturalised taxa are R. alceifolius Poir., R. ellipticus Sm., R. idaeus L., †R. laudatus A. Berger, †R. loganobaccus L.H. Bailey, †R. philadelphicus Blanch., R. roribaccus (L.H. Bailey) Rydb. and R. rugosus Sm. Patterns of morphological and molecular variation among individuals of the R. fruticosus agg. in Australia were examined. In phenetic analyses based on examination of 137 herbarium specimens and 27 morphological characters, taxa showed varying degrees of separation. Some taxa, for example R. anglocandicans and the two varieties of R. ulmifolius, formed distinct groups in these analyses whereas there was considerable overlap among individuals of other species. Fifty M13/HaeIII DNA-banding patterns (phenotypes) were identified among 198 collections from the R. fruticosus agg. across Australia. Thirty-five DNA phenotypes were correlated with 15 taxa of the R. fruticosus agg.; the remaining 15 DNA types correlated poorly or were determined with only a moderate level of confidence. R. anglocandicans, R. echinatus, R. leightonii, R. leucostachys, R. sp. Tasmania, R. ulmifolius and R. vestitus had two or more DNA phenotypes whereas only one DNA phenotype was observed for the remaining eight taxa. Taxa that were more distinct with respect to their DNA phenotypes also tended to be more distinct with respect to morphology based on a Mantel matrix correlation test. Within taxa that were difficult to tell apart morphologically, those sharing the same DNA phenotype were considered members of the same Rubus taxon. These results are discussed in the context of the evolution and ecology of the R. fruticosus agg. in Australia and in relation to the incomplete taxonomy of Rubus in Europe and North America.

Diversity of ectomycorrhizas associated with Quercus garryana in southern Oregon

We investigated diversity of ectomycorrhizas associated with Quercus garryana Dougl. ex Hook. (Oregon white oak, or Garry oak) at Whetstone Savanna Preserve in southern Oregon. Based on morphotyping and DNA restriction fragments, we described 39 ectomycorrhizas. The most common five morphotypes were found in 5% or more of 160 soil cores. Cenococcum geophilum, the most abundant morphotype, occurred in 75% of soil cores. Another common morphotype yielded a restriction fragment length polymorphism (RFLP) pattern similar to that of Tuber species. Uncommon morphotypes were responsible for the majority of ectomycorrhizal diversity on Q. garryana. Morphotype diversity of seedlings was more similar to that of their parent tree than to seedlings under other trees. Internal transcribed spacer (ITS) – RFLP patterns of ectomycorrhizas found beneath sporocarps did not match those of the sporocarps fruiting above ground. An understanding of the diversity of the ectomycorrhizal community on Q. garryana will enable us to compare ectomycorrhizas on other oak species and habitats; determine seasonality of ectomycorrhizal growth; evaluate treatments such as fire, grazing, invasion by exotic plants, and other anthropogenic disturbances; and aid restoration protocols.Key words: biocomplexity, biodiversity, ectomycorrhizas, hypogeous fungi, morphotypes, Peziza infossa, Tuber.