Evaluation of the Essen Rotary as a new technique for bacterial swabs: results of a prospective controlled clinical investigation in 50 patients with chronic leg ulcers.

Most chronic wounds are colonised with different microorganisms, especially problematic bacteria like methicillin-resistant Staphylococcus aureus (MRSA), which represent an increasing therapeutic challenge in the modern wound therapy regimen. Therefore, it is essential to specify the bacteria in wounds for an individual-specific treatment. In most patients, an exemplary bacterial swab is taken from the centre of the wound surface. This so-called Levine technique is propagated currently as the gold standard. The aim of our clinical investigation was to compare the results of different swab techniques to the new established Essen Rotary. In this monocentric prospective investigation, 50 patients with chronic leg ulcers were examined consecutively. The results of our clinical study show that bacteria are heterogeneously spread on wound surfaces. The analysis of the semiquantitative measured results showed that the Essen Rotary could detect significant more bacteria with a total amount of 111 bacteria (P = 0·049) compared to usual swab techniques. Considerably, only the Essen Rotary identified five compared to three MRSA-patients detected by other techniques. The Essen Rotary is an efficient, economic and uncomplicated modification of bacteriological swab techniques which detects significant more bacteria compared to other conventional swab techniques. Therefore, the Essen Rotary may become the new gold standard in routinely taken bacteriological swabs especially for MRSA screenings in patients with chronic leg ulcers.

Neochlamydia hartmannellae gen. nov., sp. nov. (Parachlamydiaceae), an endoparasite of the amoeba Hartmannella vermiformis.

Free-living amoebae are increasingly being recognized to serve as vehicles of dispersal for various bacterial human pathogens and as hosts for a variety of obligate bacterial endocytobionts. Several Chlamydia-like Acanthamoeba endocytobionts constituting the recently proposed family Parachlamydiaceae are of special interest as potential human pathogens. In this study coccoid bacterial endocytobionts of a Hartmannella vermiformis isolate were analysed. Infection of H. vermiformis with these bacteria resulted in prevention of cyst formation and subsequent host-cell lysis. Transfection experiments demonstrated that the parasites were not capable of propagating within other closely related free-living amoebae but were able to infect the distantly related species Dictyostelium discoideum. Electron microscopy of the parasites revealed typical morphological characteristics of the Chlamydiales, including the existence of a Chlamydia-like life-cycle, but indicated that these endocytobionts, in contrast to Chlamydia species, do not reside within a vacuole. Comparative 16S rRNA sequence analysis showed that the endocytobiont of H. vermiformis, classified as Neochlamydia hartmannellae gen. nov., sp. nov., is affiliated to the family Parachlamydiaceae. Confocal laser scanning microscopy in combination with fluorescence in situ hybridization using rRNA-targeted oligonucleotide probes confirmed the intracellular localization of the parasites and demonstrated the absence of other bacterial species within the Hartmannella host. These findings extend our knowledge of the phylogenetic diversity of the Parachlamydiaceae and demonstrate for the first time that these endocytobionts can naturally develop within amoebae of the genus Hartmannella.