To investigate azole resistance in clinical Aspergillus isolates, we conducted prospective multicenter international surveillance. A total of 3,788 Aspergillus isolates were screened in 22 centers from 19 countries. Azole-resistant A. fumigatus was more frequently found (3.2% prevalence) than previously acknowledged, causing resistant invasive and noninvasive aspergillosis and severely compromising clinical use of azoles.
We have analyzed 40 metallo--lactamase (MBL)-producing isolates of Pseudomonas aeruginosa (n ؍ 38), Pseudomonas putida (n ؍ 1), and Acinetobacter genospecies 3 (n ؍ 1) from 17 hospitals in 12 cities in Poland that were identified in 2000 to 2004. Pulsed field gel electrophoresis typing classified the P. aeruginosa isolates into eight types, with two types differentiated further into subtypes. Each of the types was specific either to a given center or to several hospitals of the same or neighboring geographic area. Almost all of the organisms produced -lactamase VIM-2; the only exceptions were several P. aeruginosa isolates from two centers which expressed VIM-4. The bla VIM genes resided exclusively within class 1 integrons, and these were located in either chromosomal or plasmid DNA. PCR-restriction fragment length polymorphism study of the variable regions of the integrons, followed by DNA sequencing, revealed the presence of eight different, mostly novel gene cassette arrays, six of which contained bla VIM-2 and two of which contained bla VIM-4 . The occurrence of the integron variants correlated well with the geographic distribution of the MBL-producing organisms, and this suggested that their emergence in particular parts of the country had been likely due to a number of independent events. The following regional dissemination of MBL producers could be attributed to various phenomena, including their clonal spread, horizontal transmission of resistance determinants, or both. All of the data collected in this study revealed that even at this early stage of detection, the epidemiological situation concerning MBL producers in Poland has already been complex and very dynamic.The class B metallo--lactamases (MBLs), which hydrolyze penicillins, cephalosporins, and carbapenems and are not inhibited by site-directed -lactam inhibitors (3), have become a problem with potentially disastrous consequences for therapy of bacterial infections in future (16,34,37). The acquired MBL variants first appeared at the end of the 1980s in Pseudomonas aeruginosa in Japan (35), and since the mid-1990s, they have been observed in many countries all over the world. So far P. aeruginosa has remained the major producer of these enzymes; however, their genes effectively diffuse into other gram-negative bacteria as well. Of the four evolutionary families of acquired MBLs discerned until now, the IMP-and VIM-type
Candida glabrata is currently ranked as the second most frequently isolated aetiological agent of human fungal infections, next only to Candida albicans. In comparison with C. albicans, C. glabrata shows lower susceptibility to azoles, the most common agents used in treatment of fungal infections. Interestingly, the mechanisms of resistance to azole agents in C. albicans have been much better investigated than those in C. glabrata. The aim of the presented study was to determine the mechanisms of resistance to azoles in 81 C. glabrata clinical isolates from three different hospitals in Poland. The investigation was carried out with a Sensititre Yeast One test and revealed that 18 strains were resistant to fluconazole, and 15 were cross-resistant to all other azoles tested (voriconazole, posaconazole and itraconazole). One isolate resistant to fluconazole was cross-resistant to voriconazole, and resistance to voriconazole only was observed in six other isolates. All strains were found to be susceptible to echinocandins and amphotericin B, and five were classified as resistant to 5-fluorocytosine. The sequence of the ERG11 gene encoding lanosterol 14-a demethylase (the molecular target of azoles) of 41 isolates, including all strains resistant to fluconazole and three resistant only to voriconazole, was determined, and no amino acid substitutions were found. Real-time PCR studies revealed that 13 of 15 azole-resistant strains showed upregulation of the CDR1 gene encoding the efflux pump. No upregulation of expression of the CDR2 or ERG11 gene was observed.
Amplification of DNA fragments surrounding rare restriction sites (ADSRRS-fingerprinting) is a novel assay based on suppression of polymerase chain reaction (PCR). This phenomenon allows the amplification of only a limited subset of DNA fragments, since only those with two different oligonucleotides ligated at the ends of complementary DNA strands are amplified in the PCR. The DNA fragments can be easily analyzed on polyacrylamide gels, stained with ethidium bromide. We have implemented this method using a set of clinical Serratia marcescens isolates from three outbreaks ongoing in the Public Hospital in Gdańsk (Poland). Clustering of ADSRRS-fingerprinting data matched epidemiological, microbiological, random amplification of polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) data. Based on this study, we found that there is at least a similar power of discrimination between the present 'gold-standard' PFGE and the novel method, ADSRRS-fingerprinting. Although the ADSRRS-fingerprinting method may appear to be more complex than the RAPD technique, we found it fast and reproducible.
BackgroundThe aim of this study was to evaluate whether the type of the mesh and proper surgical technique can influence the outcome of a tension-free hernia repair in a contaminated filed.Materials and methodsThis study was based on the model of bacterial peritonitis in rats induced with a mixture composed of Escherichia coli and Bacteroides fragilis. Two animals were used as a control group without induced peritonitis and 10 animals with mesh implanted inside of the peritoneal cavity. For the 20 animals in the studied group, bacterial fluid was applied into the abdominal cavity together with the mesh implantation. In 10 cases, the mesh was fixed flatly upon the surface of the peritoneum; in the other 10, the mesh was rolled and then fixed within the peritoneal cavity. After 5 weeks, the animals were operated on again, and the meshes, the peritoneal fluid and, if present, any granulomas were taken for bacterial cultivation.ResultsThe results of the bacterial cultivation of the material from the control group (without mesh) and from the rats with flatly fixed mesh were almost completely negative (0/10 and 1/10, respectively). In 9 out of 10 rats that were exposed to the rolled mesh for 5 weeks, the colonisation of meshes with both B. fragilis and E. coli was found (p < 0.0198).ConclusionsWhen properly fixed, flat mesh, even in a contaminated field, may allow for a proper mesh healing and does not influence the ability to cure bacterial peritonitis in an animal model. A bad surgical technique, such as inadequately positioned or rolled mesh, may cause persistent peritoneal bacteraemia.
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