Antioxidant Potential is Correlated to ω6 / ω3 Ratio and Brasfield Score in Cystic Fibrosis Children

International audienceOBJECTIVES:Oxidative stress is associated with the condition of cystic fibrosis (CF), but no guidelines exist for its assessment or treatment. Our aim was to evaluate a test that measures the blood antioxidant capability in CF children.METHODS:This antioxidant capability was assessed by the Kit Radicaux Libres (KRL) test in 44 CF children (24 boys). We recorded also anthropometric measures, pulmonary function, CF severity scores, and plasma nutritional and inflammatory parameters (proteins, vitamins, erythrocyte fatty acids, and micronutrients). We performed univariate and multivariate analyses with linear regression models.RESULTS:The mean age at the first KRL assessment was 12.2 ± 3.8 years. Factors that correlated with decreased antioxidant capacity were mostly related to the severity of pulmonary disease [ forced expiratory volume at 1 second (FEV1), acute exacerbation, and congestion. In multivariate analysis, the correlation between Brasfield score and erythrocyte antioxidant potential remained significant (β = - 0.611, p < 0.001). Among nutritional factors, the ω6/ω3 ratio was significantly correlated to erythrocyte antioxidant potential (β = - 1.213, p = 0.01).CONCLUSION:The blood antioxidant capability, measured by the KRL test, appears to be an interesting biomarker to evaluate oxidative stress in CF. This study suggests that the ω6/ω3 ratio should be regarded as a nutritional marker in antioxidant management in CF children

AdeIJK, a Resistance-Nodulation-Cell Division Pump Effluxing Multiple Antibiotics in Acinetobacter baumannii▿

We have identified a second resistance-nodulation-cell division (RND)-type efflux pump, AdeIJK, in clinical isolate Acinetobacter baumannii BM4454. The adeI, adeJ, and adeK genes encode, respectively, the membrane fusion, RND, and outer membrane components of the pump. AdeJ belongs to the AcrB protein family (57% identity with AcrB from Escherichia coli). mRNA analysis by Northern blotting and reverse transcription-PCR indicated that the genes were cotranscribed. Overexpression of the cloned adeIJK operon was toxic in both E. coli and Acinetobacter. The adeIJK genes were detected in all of the 60 strains of A. baumannii tested. The two latter observations suggest that the AdeIJK complex might contribute to intrinsic but not to acquired antibiotic resistance in Acinetobacter. To characterize the substrate specificity of the pump, we have constructed derivatives of BM4454 in which adeIJK (strain BM4579), adeABC (strain BM4561), or both groups of genes (strain BM4652) were inactivated by deletion-insertion. Determination of the antibiotic susceptibility of these strains and of BM4652 and BM4579, in which the adeIJK operon was provided in trans, indicated that the AdeIJK pump contributes to resistance to β-lactams, chloramphenicol, tetracycline, erythromycin, lincosamides, fluoroquinolones, fusidic acid, novobiocin, rifampin, trimethoprim, acridine, safranin, pyronine, and sodium dodecyl sulfate. The chemical structure of these molecules suggests that amphiphilic compounds are the preferred substrates. The AdeABC and AdeIJK efflux systems contributed in a more than additive fashion to tigecycline resistance

GES-11, a Novel Integron-Associated GES Variant in Acinetobacter baumannii▿

New extended-spectrum β-lactamase GES-11 was detected in Acinetobacter baumannii BM4674. The enzyme conferred resistance to β-lactams, including aztreonam, and reduced susceptibility to carbapenems. The structural gene was part of a class 1 integron borne by self-transferable plasmid pIP847. GES-type β-lactamases have not been reported previously in A. baumannii

A novel cgMLST for genomic surveillance of <i>Yersinia enterocolitica</i> infections in France allowed the detection and investigation of outbreaks in 2017–2021

International audienceEnteric yersiniosis, the third most common food-borne zoonosis in Europe, is mainly caused by the pathogen Yersinia enterocolitica. In France, the yersiniosis microbiological surveillance is conducted at the Yersinia National Reference Laboratory (YNRL). Since 2017, isolates have been characterized by whole genome sequencing (WGS) followed by a 500-gene Yersinia-cgMLST. We report here the data of the WGS-based surveillance on Y. enterocolitica isolates for the 2017-2021 period. The YNRL characterized 7,642 Y. enterocolitica strains distributed in 2,497 non-pathogenic isolates from lineages 1Aa and 1Ab, and 5,145 specimens belonging to 8 pathogenic lineages. Among pathogenic isolates, lineage 4 was the most common (87.2%) followed by lineages 2/3-9b (10.6%), 2/3-5a (1.2%), 2/3-9a (0.6%), 3-3b, 3-3c, 1B, and 3-3d (0.1% per each). Importantly, we developed a routine surveillance system based on a new typing method consisting of a 1,727-genes core genome Multilocus Sequence Typing (cgMLST) specific to the species Y. enterocolitica followed by isolate clustering. Thresholds of allelic distances (AD) were determined and fixed for the clustering of isolates: AD ≤ 5 for lineages 4, 2/3-5a, and 2/3-9a, and AD ≤ 3 for lineage 2/3-9b. Clustering programs were implemented in 2019 in routine surveillance to detect genomic clusters of pathogenic isolates. In total, 419 clusters with at least 2 isolates were identified, representing 2,504 of the 3,503 isolates characterized between 2019 and 2021. Most clusters (n = 325) comprised 2 to 5 isolates. The new typing method proved to be useful for the molecular investigation of unusual grouping of cases as well as for the detection of genomic clusters in routine surveillance

rVHSV expressing WNV E antigens induce IgG and neutralizing antibody production.

<p>(a) 5-week-old BALB/c mice in groups of 12 animals were immunized three times by subcutaneous (SC) injection.</p><p>(b) The titers of total IgG, IgG1 or IgG2a produced in immunized mice were determined by ELISA. The sera of 12 mice per group were harvested the day of the challenge (day 56) and pooled. The titer is the reciprocal of the last dilution at which the OD value measured is two times higher than the negative control (serum from day 0 for each group).</p><p>(c) The production of neutralizing antibodies was demonstrated by WNV neutralization assay. The titer of neutralizing antibodies is the reciprocal of the last dilution for which no CPE could be observed. Individuals with serum neutralization titers ≥ 30 are considered as positive.</p

Is Yersinia bercovieri Surpassing Yersinia enterocolitica in Wild Boars (Sus scrofa)?

International audienceYersiniosis was the fourth reported zoonosis in the European Union in 2018. As well-known, pigs are recognized important reservoirs of Yersinia enterocolitica. The study was focused on Y. enterocolitica detection in mesenteric lymph nodes and faeces of 305 wild boars, but Yersinia bercovieri was more common, being isolated from 108 animals (35.4%). Cold season (p = 1.17 9 10-5) and young age (p = 0.004) significantly increased Y. bercovieri detection. Y. enterocolitica 1A belonging to six serotypes (O:4.32-4.33; O:5; O:6.30-6.31; O:7.8-8-8.19; O:10-34; O:12.25-12.26) was isolated from 8.2% (25/305) of the animals. Cold season significantly affected (p = 0.037) Y. enterocolitica detection

Chikungunya antibodies detected in non-human primates and rats in three Indian Ocean islands after the 2006 ChikV outbreak

International audienceThe role of terrestrial vertebrates in the epidemiology of chikungunya disease is poorly understood. We evaluated their exposure and amplification role during the 2006 chikungunya outbreak in the Indian Ocean. Blood samples were collected from 18 mammalian and reptile species from Reunion Island, Mauritius and Mayotte. Among the 1051 samples serologically tested for chikungunya virus (CHIKV), two crab-eating macaques (Macaca fascicularis) and two ship rats (Rattus rattus) proved to be exposed to CHIKV. CHIKV RNA was not detected in 791 analyzed sera. Our results confirm the preferential infection of simian primates and suggest that other vertebrates played a poor or no role in CHIKV transmission during the 2006 outbreak

Is Yersinia bercovieri surpassing Yersinia enterocolitica in wild boars (Sus scrofa)?

Yersiniosis was the fourth reported zoonosis in the European Union in 2018. As well-known, pigs are recognized important reservoirs of Y. enterocolitica. The study was focused on Y. enterocolitica detection in mesenteric lymph nodes and rectal samples of 305 wild boars, but Y. bercovieri was more common, being isolated from 108 animals (35.4%). Cold season (p = 1.17*10-5) and young age (p = 0.004) significantly increased Y. bercovieri detection. Y. enterocolitica 1A belonging to six serotypes (O:4,32-4,33; O:5; O:6,30-6,31; O:7,8-8-8,19; O:10-34; O:12,25-12,26) was isolated from 8.2% (25/305) of the animals. Cold season significantly affected (p = 0.037) Y. enterocolitica detection

Individual production of total IgG after immunization with rVHSV-SP_GE_VWN and rVHSV-SP_GE_VWNΔTMTM_G.

<p>5-week-old BALB/c mice in groups of 12 individuals were immunized three times with different antigens as indicated (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0091766#pone-0091766-g002" target="_blank">fig.2</a> for schedule details). Antibody production by each mouse was assessed by ELISA with individual sera collected on day 56 just before the WNV challenge. Each serum was diluted to 1∶100. OD values for each individual are represented directly after removal of the white (OD measured in the absence of serum).</p