Drug-resistant variants are frequently present in both recently and chronically infected therapy-naive patients. Drug-resistant variants are most commonly seen in patients infected with subtype B virus, probably because of longer exposure of these viruses to drugs. However, an increase in baseline resistance in non-B viruses is observed. These data argue for testing all drug-naive patients and are of relevance when guidelines for management of postexposure prophylaxis and first-line therapy are updated.

No abstract

Recent outbreaks of Clostridium difficile-associated diarrhoea (CDAD) with increased severity, high relapse rate and significant mortality have been related to the emergence of a new, hypervirulent C. difficile strain in North America, Japan and Europe. Definitions have been proposed by the European Centre of Disease Prevention and Control (ECDC) to identify severe cases of CDAD and to differentiate community-acquired cases from nosocomial CDAD (http://www.ecdc.europa.eu/documents/pdf/Cl_dif_v2.pdf). CDAD is mainly known as a healthcare-associated disease, but it is also increasingly recognised as a community-associated disease. The emerging strain is referred to as North American pulsed-field type 1 (NAP1) and PCR ribotype 027. Since 2005, individual countries have developed surveillance studies to monitor the spread of this strain. C. difficile type 027 has caused outbreaks in England and Wales, Ireland, the Netherlands, Belgium, Luxembourg, and France, and has also been detected in Austria, Scotland, Switzerland, Poland and Denmark. Preliminary data indicated that type 027 was already present in historical isolates collected in Sweden between 1997 and 2001.

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The prevalence and the genotypic and phenotypic characteristics of multinucleoside-resistant (MNR) human immunodeficiency virus type 1 (HIV-1) variants in Europe were investigated in a multicenter study that involved centers in nine European countries. Study samples (n ‫؍‬ 363) collected between 1991 and 1997 from patients exposed to two or more nucleoside analogue reverse transcriptase inhibitors (NRTIs) and 274 control samples from patients exposed to no or one NRTI were screened for two marker mutations of multinucleoside resistance (the Q151M mutation and a mutation with a 2-amino-acid insertion at codon 69, T69S-XX). Q151M was identified in six of the study samples (1.6%), and T69S-XX was identified in two of the study samples (0.5%; both of them T69S-SS), but both patterns were absent among control samples. Non-NRTI (NNRTI)-related changes were observed in viral strains from two patients, which displayed the Q151M resistance pattern, although the patients were NNRTI naive. The patients whose isolates displayed multinucleoside resistance had received treatment with zidovudine and either didanosine, zalcitabine, or stavudine. Both resistance patterns conferred broad cross-resistance to NRTIs in vitro and a poor response to treatment in vivo. MNR HIV-1 is found only among multinucleoside-experienced patients. Its prevalence is low in Europe, but it should be closely monitored since it seriously limits treatment options.

Based on the calculated genetic barrier, the rate of drug resistance development may be similar for different HIV-1 subtypes. Because of differences in minor protease substitutions, protease inhibitor resistance could be enhanced in particular subtypes once the relevant major substitutions are selected.

Phylogenetic analysis of 166 human parvovirus B19 sequences from 11 different countries attributed 91.57% to genotype 1, 5.42% to genotype 3b, and 3.01% to genotype 3a. Very similar viruses of genotype 1 circulated widely in Europe and Israel. Genotype 3b seems to show an increasing spread outside of Africa.Human parvovirus B19 (B19V) infections are usually associated with mild disease, but in immunocompromised and anemic patients, as well as during pregnancy, severe complications can occur. Based on the genetic variability of 994 nucleotides (nt) of the NS1/VP1-unique region junction, three distinct genotypes of B19V have been proposed (13). A recent report presented evidence that certain complications might be preferentially associated with certain virus genotypes (6). Several studies demonstrated that previously published or commercially available assays show differences in their diagnostic performance, including the inability to detect certain genotypes, especially genotype 3, subtype 3b (1, 5). Despite these important implications for the diagnosis of B19V, little is known about the genotypes prevalent in many countries.Serum samples collected between 2000 and 2008 mostly from rash/fever patients negative for both measles and rubella from 11 different countries were analyzed for B19V (Table 1). A nested PCR was performed with the forward primers e1855f and e1863f (13) and reverse primers B19-R1 (5Ј-GGGAACT TCCGGCAAACTTCCTTG-3Ј) and B19-R2 (5Ј-GTAGTCTT TTACTACTTGTGCTTG-3Ј), yielding fragments of 1,239 and 1,168 nt. Previously published reverse primers (13) have a maximum of three (e2953r) and four (e2960r) mismatches compared to B19V GenBank sequences, including 3Ј and 5Ј

Campylobacter jejuni is the most common cause of bacterial gastroenteritis in Luxembourg, with a marked seasonal peak during summer. The majority of these infections are thought to be sporadic, and the relative contribution of potential sources and reservoirs is still poorly understood. We monitored human cases from June to September 2006 (n ‫؍‬ 124) by molecular characterization of isolates with the aim of rapidly detecting temporally related cases. In addition, isolates from poultry meat (n ‫؍‬ 36) and cattle cecal contents (n ‫؍‬ 48) were genotyped for comparison and identification of common clusters between veterinary and human C. jejuni populations. A total of 208 isolates were typed by sequencing the fla short variable region, macrorestriction analysis resolved by pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). We observed a high diversity of human strains during a given summer season. Poultry and human isolates had a higher diversity of sequence types than isolates of bovine origin, for which clonal complexes CC21 (41.6%) and CC61 (18.7%) were predominant. CC21 was also the most common complex found among human isolates (21.8%). The substantial concordance between PFGE and MLST results for this last group of strains suggests that they are clonally related. Our study indicates that while poultry remains an important source, cattle could be an underestimated reservoir of human C. jejuni cases. Transmission mechanisms of cattle-specific strains warrant further investigation.