Co-production of MCR-1 and extended-spectrum β-lactamase in Escherichia coli recovered from urinary tract infections in Switzerland

International audienc

Anti-Treponema pallidum IgA response as a potential diagnostic marker of syphilis

Objectives: Serological tests for syphilis detect mainly total Ig, IgM or IgG antibodies. We aimed to evaluate the specific IgA response in syphilis patients according to disease stage. Methods: A serum IgA-enzyme immunoassay was developed using commercially available microplates coated with recombinant treponemal antigens and an anti-IgA-conjugate. To define a cut-off, we used 91 syphilis positive and 136 negative sera previously defined by the rapid plasma reagin and the Treponema pallidum particle agglutination results. Then we determined the intra- and inter-assay precisions, diagnostic sensitivity according to the clinical stage (in 66, 55 and 42 sera from primary, secondary and latent syphilis patients, respectively) and specificity (in 211 sera from people with conditions different to syphilis). IgA values were further measured in 71 sera from patients with previously treated syphilis. Results: The newly developed IgA-enzyme immunoassay showed a good discrimination between negative and positive samples with intra- and inter-assay variation coefficients <20%. The sensitivity was 80.3% (95% CI, 70.0-90.6), 100.0% (95% CI, 99.1-100.0) and 95.2% (95% CI, 87.6-100.0) in primary, secondary and latent syphilis, respectively, and the specificity was 98.1% (95% CI, 96.0-100.0). Further, IgA values were negative in 61.3% (38/62) of patients with previously treated syphilis. Discussion: Our findings suggest serum IgA as a sensitive and specific marker of syphilis and its detection could be used as a screening assay for active infection. Further evaluation is needed in prospective longitudinal field studies

In vitro susceptibility of Actinobaculum schaalii to 12 antimicrobial agents and molecular analysis of fluoroquinolone resistance

Objectives To assess the in vitro susceptibility of Actinobaculum schaalii to 12 antimicrobial agents as well as to dissect the genetic basis of fluoroquinolone resistance. Methods Forty-eight human clinical isolates of A. schaalii collected in Switzerland and France were studied. Each isolate was identified by 16S rRNA sequencing. MICs of amoxicillin, ceftriaxone, gentamicin, vancomycin, clindamycin, linezolid, ciprofloxacin, levofloxacin, moxifloxacin, co-trimoxazole, nitrofurantoin and metronidazole were determined using the Etest method. Interpretation of results was made according to EUCAST clinical breakpoints. The quinolone-resistance-determining regions (QRDRs) of gyrA and parC genes were also identified and sequence analysis was performed for all 48 strains. Results All isolates were susceptible to amoxicillin, ceftriaxone, gentamicin, clindamycin (except three), vancomycin, linezolid and nitrofurantoin, whereas 100% and 85% were resistant to ciprofloxacin/metronidazole and co-trimoxazole, respectively. Greater than or equal to 90% of isolates were susceptible to the other tested fluoroquinolones, and only one strain was highly resistant to levofloxacin (MIC ≥32 mg/L) and moxifloxacin (MIC 8 mg/L). All isolates that were susceptible or low-level resistant to levofloxacin/moxifloxacin (n = 47) showed identical GyrA and ParC amino acid QRDR sequences. In contrast, the isolate exhibiting high-level resistance to levofloxacin and moxifloxacin possessed a unique mutation in GyrA, Ala83Val (Escherichia coli numbering), whereas no mutation was present in ParC. Conclusions When an infection caused by A. schaalii is suspected, there is a risk of clinical failure by treating with ciprofloxacin or co-trimoxazole, and β-lactams should be preferred. In addition, acquired resistance to fluoroquinolones more active against Gram-positive bacteria is possibl

Emergence of an MDR Klebsiella pneumoniae ST231 producing OXA-232 and RmtF in Switzerland

The increasing incidence of carbapenem-resistant Klebsiella pneumoniae is a major challenge to public health. Despite the fact that the prevalence of carbapenemases among carbapenem-resistant K. pneumoniae varies geographically, the incidence of OXA-48-like enzymes has soared in recent years and is particularly high in some European countries, such as Spain and France (74% and 78% among carbapenemase-producing K. pneumoniae, respectively).1 A significant number of OXA-48 variants have been reported in the last decade. This includes OXA-232, a carbapenemase firstly identified in France in 20112 and thereafter found in several countries.3,4 Recently, an MDR K. pneumoniae ST231 co-producing OXA-232, the ESBL CTX-M-15 and the 16S rRNA methyltransferase RmtF conferring broad- spectrum resistance to aminoglycosides has emerged as a successful epidemic..

IVDR: Analysis of the Social, Economic, and Practical Consequences of the Application of an Ordinance of the In Vitro Diagnostic Ordinance in Switzerland

IVDR regulation represents a major challenge for diagnostic microbiology laboratories. IVDR complicates a broad range of aspects and poses a risk given the high diversity of pathogens (including rare but highly virulent microbes) and the large variety of samples submitted for analysis. The regular emergence of new pathogens (including Echovirus E-11, Adenovirus 41, Monkeypox virus, Alongshan virus, and Enterovirus D68, as recent examples in Europe in the post SARS-CoV-2 era) is another factor that makes IVDR regulation risky, because its detrimental effect on production of in-house tests will negatively impact knowledge and expertise in the development of new diagnostic tests. Moreover, such regulations negatively impact the availability of diagnostic tests, especially for neglected pathogens, and has a detrimental effect on the overall costs of the tests. The increased regulatory burden of IVDR may thereby pose an important risk for public health. Taken together, it will have a negative impact on the financial balance of diagnostic microbiology laboratories (especially small ones). The already-high standards of quality management of all ISO-accredited and Swissmedic-authorized laboratories render IVDR law of little value, at least in Switzerland, while tremendously increasing the regulatory burden and associated costs. Eventually, patients will need to pay for diagnostic assays outside of the framework of their insurance in order to obtain a proper diagnostic assessment, which may result in social inequity. Thus, based on the risk assessment outlined above, the coordinated commission for clinical microbiology proposes adjusting the IvDO ordinance by (i) introducing an obligation to be ISO 15189 accredited and (ii) not implementing the IvDO 2028 milestone

Adaptive Strategies in a Poly-Extreme Environment: Differentiation of Vegetative Cells in Serratia ureilytica and Resistance to Extreme Conditions

Poly-extreme terrestrial habitats are often used as analogs to extra-terrestrial environments. Understanding the adaptive strategies allowing bacteria to thrive and survive under these conditions could help in our quest for extra-terrestrial planets suitable for life and understanding how life evolved in the harsh early earth conditions. A prime example of such a survival strategy is the modification of vegetative cells into resistant resting structures. These differentiated cells are often observed in response to harsh environmental conditions. The environmental strain (strain Lr5/4) belonging to Serratia ureilytica was isolated from a geothermal spring in Lirima, Atacama Desert, Chile. The Atacama Desert is the driest habitat on Earth and furthermore, due to its high altitude, it is exposed to an increased amount of UV radiation. The geothermal spring from which the strain was isolated is oligotrophic and the temperature of 54°C exceeds mesophilic conditions (15 to 45°C). Although the vegetative cells were tolerant to various environmental insults (desiccation, extreme pH, glycerol), a modified cell type was formed in response to nutrient deprivation, UV radiation and thermal shock. Scanning (SEM) and Transmission Electron Microscopy (TEM) analyses of vegetative cells and the modified cell structures were performed. In SEM, a change toward a circular shape with reduced size was observed. These circular cells possessed what appears as extra coating layers under TEM. The resistance of the modified cells was also investigated, they were resistant to wet heat, UV radiation and desiccation, while vegetative cells did not withstand any of those conditions. A phylogenomic analysis was undertaken to investigate the presence of known genes involved in dormancy in other bacterial clades. Genes related to spore-formation in Myxococcus and Firmicutes were found in S. ureilytica Lr5/4 genome; however, these genes were not enough for a full sporulation pathway that resembles either group. Although, the molecular pathway of cell differentiation in S. ureilytica Lr5/4 is not fully defined, the identified genes may contribute to the modified phenotype in the Serratia genus. Here, we show that a modified cell structure can occur as a response to extremity in a species that was previously not known to deploy this strategy. This strategy may be widely spread in bacteria, but only expressed under poly-extreme environmental conditions

There is inadequate evidence to support the division of the genus Borrelia

There are surely scientific, genetic or ecological 60 arguments which show that differences exist between the relapsing fever (RF) spirochaetes and the Lyme borreliosis (LB) group of spirochaetes, both of which belong to the genus Borrelia. In a recent publication, Adeolu and Gupta (Adeolu & 63 Gupta, 2014) proposed dividing the genus Borrelia into two genera on the basis of genetic differences revealed by comparative genomics. The new genus name for the LB group of spirochaetes, Borreliella, has subsequently been entered in GenBank for some species of the group and in a validation list (List of new names and new combinations previously effectively, but not validly, published) (Oren & Garrity, 2015). However, rapidly expanding scientific knowledge and considerable conflicting evidence combined with the adverse consequences of splitting the genus Borrelia make such a drastic step somewhat premature. In our opinion, the basis of this division rests on preliminary evidence and should be rescinded