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Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is commonly used by clinical microbiology laboratories to identify pathogens, despite some limitations of the technique. The Enterobacter cloacae complex (ECC) taxonomy has recently been expanded, leading to uncertain identification of some species within the ECC when commercial MALDI-TOF MS is used. This technique is especially unsuited in the case of E. hormaechei, the main species responsible for infections and one of the most prone, within the ECC, to acquire antibiotic resistance. Hence, rapid and reliable identification at the species level could improve patient management. Here, we evaluated the performance of the Bruker Microflex MALDI-TOF MS instrument to identify ECC isolates using two databases and algorithms in comparison to the hsp60 gene sequencing reference method: the Bruker database included in the MALDI Biotyper software and an extensive online database coupled to an original Mass Spectrometric Identification (MSI) algorithm. Among a panel of 94 ECC isolates tested in triplicate, the online database coupled to MSI software allowed the highest rate of identification at the species level (92%) compared to the MALDI Biotyper database (25%), especially for the species E. hormaechei (97% versus 20%). We show that by creating a database of MALDI-TOF reference spectral profiles with a high number of representatives associated with the performant MSI software, we were able to substantially improve the identification of the E. cloacae complex members, with only 8% of isolates misidentified at the species level. This online database is available through a free online MSI application (https://msi.happy-dev.fr/). IMPORTANCE Creation of a database of MALDI-TOF reference spectral profiles with a high number of representatives associated with the performant MSI software enables substantial improvement in identification of E. cloacae complex members. Moreover, this online database is available through a free online MSI application (https://msi.happy-dev.fr/).

The increasing incidence of carbapenemase-producing Gram-negative bacilli (C-PGNB) represents a major public health challenge. Rapid detection of digestive colonization with C-PGNB is fundamental to control their spread. We performed the validation of a rapid protocol for C-PGNB detection directly on rectal swabs. We developed a protocol combining enrichment by a rapid selective subculture of the rectal swab medium and realization of a Resist-4 O.K.N.V. K-SeT test on the bacterial pellet obtained. The limit of detection and performances of this protocol were validated in vitro on 52 C-PGNB strains spiked on a calibrated sample suspension and confirmed in clinical settings on 144 rectal swabs sampled from patients with C-PGNB digestive colonization (n = 48) and controls (patients with extended-spectrum beta-lactamase [ESBL] colonization [n = 48] and without carbapenemase/ESBL [n = 48]). The protocol detected, with 100% sensitivity, the presence of the 15 OXA-48-, 14 KPC-, 13 NDM-, and 10 VIM-producing GNB from 10(3) CFU/ml. The limit of detection was 2 × 10(2) CFU/ml. Among the 48 C-PGNB-containing rectal swabs of the validation cohort, 46 were accurately detected. False negative were observed for 1 NDM-producing Acinetobacter baumannii strain and 1 OXA-48-producing Escherichia coli strain. The 96 control swabs were negative. Sensitivity and specificity for C-PGNB detection were 97.7% (95% confidence interval [CI], 87.7 to 100) and 100% (95% CI, 96.2 to 100). The negative likelihood ratio was 0.04 (95% CI, 0.01 to 0.16). Considering a C-PGNB digestive colonization prevalence between 0.01% and 0.1%, positive and negative predictive values were 100%. Our protocol is a rapid and low-cost method detecting accurately the digestive colonization with carbapenemase-producing Enterobacteriaceae in 4 h without any requirement for specific equipment.

FosA, a glutathione S-transferase that inactivates fosfomycin, has been reported as the cause of enzymatic resistance to fosfomycin. We show that multiple lineages of FosA-producing extended spectrum β-lactamase Escherichia coli have circulated in France since 2012, potentially reducing the efficacy of fosfomycin in treating infections with antimicrobial drug-resistant gram-negative bacilli.

Green tea is widely used as a &lsquo, &rsquo, healthy&rsquo, beverage due to its high level of antioxidant polyphenol compounds. However tea is also known to contain significant amount of oxalate. The objective was to determine, in a cross-sectional observational study among a population of 273 hypercalciuric stone-formers referred to our center for metabolic evaluation, whether daily green tea drinkers (n = 41) experienced increased stone risk factors (especially for oxalate) compared to non-drinkers. Stone risk factors and stone composition were analyzed according to green tea status and sex. In 24-h urine collection, the comparison between green tea drinkers and non-drinkers showed no difference for stone risk factors such as urine oxalate, calcium, urate, citrate, and pH. In females, the prevalence of calcium oxalate dihydrate (COD) and calcium phosphate stones, assessed by infrared analysis (IRS) was similar between green tea drinkers and non-drinkers, whereas prevalence of calcium oxalate monohydrate (COM) stones was strikingly decreased in green tea drinkers (0% vs. 42%, p = 0.04), with data in accordance with a decreased oxalate supersaturation index. In males, stone composition and supersaturation indexes were similar between the two groups. Our data show no evidence for increased stone risk factors or oxalate-dependent stones in daily green tea drinkers.

Despite adequate immunization and penicillin prophylaxis, bacterial infections remain a leading cause of morbidity and mortality in patients with sickle cell disease (SCD). Besides hyposplenism, inflammatory and genetic factors might modulate their susceptibility to bacterial infections. We performed a candidate gene association of single nucleotide polymorphisms (SNPs) located in Toll-like receptor (TLR) genes, encoding prominent molecules for innate immune responses, with the occurrence of bacterial infections in patients with SCD. A cohort followed in centres in Brazil, France and Senegal (n = 430) was divided in two groups: patients who presented at least one episode of bacterial infection (n = 235) and patients who never had bacterial infections (n = 195). There were no differences in gender or age distribution among the groups. The frequency of the TLR2 rs4696480 TA genotype was significantly lower in the infected group (50% vs. 67%, odds ratio [OR] = 0·50, 95% confidence interval [CI] 0·34-0·75, P

Summary The management of sickle cell nephropathy (SCN) at an early stage is an important issue to prevent renal and cardiovascular morbidity and mortality. This study aimed to evaluate in this population, whether angiotensin converting enzyme inhibitors (ACEIs) treatment could exert a cardio-renal protection in a SCN cohort. Forty-two SCN patients (urine albumin:creatinine ratio (ACR) > 10 mg/mmol) were treated with ACEIs for 6 months, then evaluated for ACR, measured glomerular filtration rate (mGFR) together with haematological and cardiovascular parameters. A 1-month washout was also performed in order to differentiate short- and long-term ACEIs effects. A decrease in ACR baseline value (>30%) was detected in 62% of cases (mean ACR: 46·4 ± 7·6 and 26·4 ± 3·9 mg/mmol at baseline and 6 months respectively; P = 0·002), whereas mGFR values were unchanged. ACR decrease was detected at 1 month following ACEI initiation (32·9 ± 6·9, P = 0·02) with a persistent trend after withdrawal (P = 0·08). ACEIs also decreased diastolic blood pressure (P = 0·007), pulse wave velocity (P = 0·01), tricuspid regurgitation velocity (TRV; P = 0·04), asymmetric dimethyl arginine (ADMA: P = 0·001) and haemoglobin (P = 0·01) while conventional haemolytic biomarkers were unchanged. Our data suggest that ACEIs are safe and effective at decreasing albuminuria in sickle cell patients with a beneficial effect on specific mortality risk factors, such as TRV and asymmetric dimethyl arginine.

Background: Patients (pts) with sickle cell disease (SCD) show a high phenotype variability that is not fully understood. Because inflammation plays a major role in SCD pathophysiology, we hypothesized that single nucleotide polymorphisms (SNPs) in genes of innate and adaptative inflammatory response modulate the occurrence of SCD complications. Objective: to establish associations between SNPs and clinical complications in pts with SCD. Methods: Case-control retrospective study; 500 pts were included, followed at Senegal (n=56), Brazil (n=230) and France (n=214). We analyzed the effect of 20 SNPs in 6 clinical complications: acute chest syndrome (ACS), stroke, leg ulcers, cholelithiasis, osteonecrosis and retinopathy. Using TaqMan 5'-nuclease assay, we genotyped SNPs in genes encoding Toll-like receptor (TLR) 1 (rs4833095), 2 (rs4308099, rs4308100, rs4696480), 6 (rs5743810), 10 (rs11466653, rs11096957), natural killer (NK) group 2 member D (NKG2D) receptor (rs1982536, rs2617160, rs2617169, rs2617170, rs2617171, rs1049174, rs2246809, rs2255336), human leukocyte antigen (HLA)-G (rs9380142), HLA-E (rs2517523), major histocompatibility complex class I polypeptide-related sequence A (MICA, rs1051792) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) (rs5742909, rs231775). All SNPs had a call rate >90% and minimum allele frequency >1%. We performed analyses of correspondence for indicating associations between SNPs and number of clinical complications. Logistic regressions were used to identify associations between SNPs and each complication, using geographical origin, SCD genotype, rate of transfusions and gender for modeling adjustment; the significance was adjusted for multiple testing using false discovery rate. Comparisons of genotype frequencies with the population of African descent from 1000 genomes database were done by chi-square. Results: Pts were originally from Brazil (n=228), Sub-Saharan Africa (n=200), French West Indies (n=53), North Africa (n=7) and 12 unknown. SCD genotype (available n=498) was SS (n=402), SC (n=46), SB (n=42), SD or SE (n=4). 280 pts were female; median age was 32 years (range 0-69); 184 pts received at least 20 transfusions. 71 pts presented stroke, 200 had at least 1 episode of ACS, 69 had leg ulcers, 271 had cholelithiasis, 150 had retinopathy and 90 osteonecrosis. 97 pts did not present complications, 135 had 1 type of clinical complication, 134 had 2, 94 had 3, 34 had 4 and 6 had 5. 21 pts underwent hematopoietic stem cell transplantation. 11 pts died during follow-up, mostly from ACS and hemorrhagic stroke. Indication of association with number of complications: TLR2 rs4696480 TA, TLR2rs3804099 CC and HLA-Grs9380142 AA were associated with occurrence of 0-1 clinical complications, MICA rs1051792 AA/AG with up to 2 complications and NKG2D rs2617169 AA with 5 complications. Association between genotypes/haplotypes and each complication: no association was found between SNPs and stroke, ACS, leg ulcers and osteonecrosis. Rs9380142 was the only SNP significantly associated with cholelithiasis in the logistic regression additive model. The G allele increased the risk of cholelithiasis (AG x AA, OR 1.57, 95%CI 1.16-2.15; GGxAA, OR 2.47, 95%CI 1.34-4.64; P=0.02). For retinopathy, in the logistic regression additive model, the presence of the A allele decreased the risk of retinopathy for rs2246809 in pts of same origin (AAxGG: OR 0.22, 95%CI 0.09-0.50; AGxGG: OR 0.47, 95%CI 0.31-0.71; P=0.004), rs2617160 (ATxTT: OR 0.67, 95%CI 0.48-0.92; AAxTT: OR 0.45, 95%CI 0.23-0.84; P=0.04) and rs2617169 in pts of same SCD genotype (AAxTT: OR 0.33,95%CI 0.13-0.82; ATxTT: OR 0.58, 95%CI 0.36-0.91, P=0.049). No haplotype was associated with complications. The genotype distribution of SNPs rs4696480, rs3804099, rs1051792 and rs2617169 differed significantly from the population of African descent from the 1000 genomes database. Discussion: We have previously shown that TLR2 rs4696480 TA decreases occurrence of bacterial infections in SCD; in this study, TA is also associated with less complications. Also, HLA-G rs9380142 AA had less complications and cholelithiasis, and 3 SNPs in NKG2D modulated occurrence of retinopathy. TLR and NKG2D may be activated by heat shock proteins, released in ischemia-reperfusion injury that occurs in SCD. Our findings help to better understand the role of inflammation in phenotype heterogeneity in SCD. Disclosures No relevant conflicts of interest to declare.

Background: Sickle cell disease (SCD) patients (pts) are at increased risk of infection. This susceptibility is partially explained by the loss of spleen function, but other factors such as inflammatory status might also play a role. Despite adequate immunization and antimicrobial prophylaxis, bacterial infection remains a major cause of morbidity and mortality in SCD pts. Toll-like receptors (TLR), transmembrane proteins that recognize a wide range of pathogen molecular patterns, are key receptors in innate immune response. The association among TLR and infections in SCD has scarcely been explored. Objective: To analyze if functional polymorphisms in TLR genes can modulate the susceptibility to bacterial infections in SCD pts. Methods: Case-control retrospective study; 430 SCD pts followed in university hospitals in Brazil (n=196), France (n=180, mainly from Subsaharan Africa and French West Indies) and Senegal (n=54) were included. Sites of bacterial infection were lower respiratory system, abdominal, upper urinary system, bone/joints, central nervous system, blood stream, or any site for tuberculosis. For pts who underwent hematopoietic stem cell transplant (HSCT), only bacterial infections before HSCT were considered. All pts were tested for 7 single nucleotide polymorphisms (SNP) in TLR-1(rs4833095), TLR-2 (rs4696480, rs3804099, rs3804100), TLR-6 (rs5743810) and TLR-10 (rs11466653, rs11096957) using TaqMan 5'-nuclease assay. Univariate analysis was performed with chi-square or Mann-Whitney for categorical and continuous variables respectively. Associations were measured by odds ratio (OR). For SNP associations, significant P-value corrected by Bonferroni (cP) was 0.007; for genetic models, cP was 0.01. Results: Median age of cohort was 30 years (range: 2-70) and 87% were ≥18 years; 57% of pts were female. SCD genotype was SS in 81%, SC in 11%, SB in 7% and other in 1%. Fifty-eight percent received hydroxyurea and 79% received red blood cell transfusions; seven pts underwent HSCT. Eleven pts died during follow-up, mostly from acute chest syndrome and hemorrhagic stroke. All pts had access to immunization against encapsulated bacteria and to penicillin prophylaxis. One hundred ninety-five pts (45%) did not present any bacterial infection, whereas 235 (55%) pts presented at least one episode of bacterial infection, of which 20% had ≥ 3 episodes. Bacterial infections were mainly respiratory (51%), bone/joints (23%) and urinary (20%). In 106 cases, etiological agents were identified; most common agents were Escherichia coli, Streptococcuspneumoniae, Mycobacterium tuberculosis and Salmonella spp. In univariate analysis, there was no association among occurrence of infections and gender, origin and age distribution. Gene analysis: all tested SNPs had a typing rate >90% and minimum allele frequency >1%. The TLR-2 SNP rs4696480 (n=425) showed significant association with infection (p Discussion: In SCD pts, TLR-2 rs4696480 TA genotype might be protective against bacterial infections, whereas TT genotype might increase risk of such infections. Previous reports demonstrated higher secretion of inflammatory factors in cells from AA individuals, lower occurrence and severity of immune diseases in T carriers. TA genotype might stand between deleterious effects of over inflammatory response (AA genotype) and under response (TT genotype) to infectious agents. Disclosures No relevant conflicts of interest to declare.

An atypical Enterobacteriaceae strain with a β-lactam susceptibility pattern of inducible cephalosporinase was isolated in Tenon Hospital (Paris, France) from a patient’s skull wound infection. Identifications by the API-50CHE biochemical system and 16S rRNA gene sequencing concluded that it was a member of the Buttiauxella genus. The bla gene was cloned and sequenced. The deduced translated product was a 383-amino acid protein (BUT-1) with 75–78% identity with the chromosomal AmpC β-lactamases of Citrobacter freundii , Enterobacter aerogenes , Enterobacter cloacae and Escherichia coli . The isoelectric point of 9.0 and the kinetic constants of BUT-1 were comparable with results described for other Ambler class C enzymes. bla BUT-1 and the associated ampR transcriptional regulator gene were divergently transcribed from a common intercistronic region, a genetic organization already described for other inducible class C β-lactamases. The deduced amino acid sequence of AmpR shared 85% and 81% identity with AmpR from E. cloacae and C. freundii respectively.

Ralstonia paucula (formerly CDC group IV c-2) is an environmental organism that can cause serious human infections, occasionally clusters of nosocomial infections. In the present work, 26 strains of R. paucula (4 from the American Centers for Disease Control and Prevention collection, 10 from the Belgian Laboratorium voor Microbiologie [LMG] collection, and 12 French clinical isolates) were analyzed with infrequent-restriction-site PCR and randomly amplified polymorphic DNA analysis. Both techniques accurately distinguished between collection strains. Two close patterns obtained for all the French isolates suggested a clonal strain. Two LMG collection strains originating from human sources in the United States also showed patterns close to those of French isolates.

Eleven Klebsiella pneumoniae clinical isolates and one Klebsiella oxytoca clinical isolate showing various pulsed-field gel electrophoresis types and producing an inducible DHA-1 class C β-lactamase were isolated in the Parisian region between 1998 and 2003. The aim of this study was to compare the genetic organization of the bla DHA-1 genes in this collection of clinical isolates. In four isolates, the Morganella morganii -derived genomic region containing bla DHA-1 was inserted in an entire complex sul1 -type integron, including a region common to In6-In7 (CR1), as previously described in a bla DHA-1 -producing Salmonella enterica serovar Enteritidis KF92 isolate from Saudi Arabia in 1992. Different gene cassette arrays were characterized in each of these integrons. In two of them, an additional 10-kb fragment was inserted between the CR1 and the M. morganii -derived region and was similar to the sap (ABC transporter family) and psp (phage shock protein) operons originated from Salmonella enterica serovar Typhimurium. The length of the M. morganii region was variable, suggesting that several independent recombination events have occurred and that open reading frame orf513 encodes a recombinase involved in the mobilization of the resistance genes. The genetic organization of bla DHA-1 was identical in the eight other isolates. This structure is likely derived from a complex integron following the insertion of IS 26 , leading to the deletion of the first part of integron. The horizontal transfer of one plasmid carrying that truncated integron was shown for seven of these isolates.

The amplification and sequence of ampC genes in Enterobacter asburiae, Enterobacter cancerogenus, Enterobacter dissolvens, Enterobacter hormaechei and Enterobacter intermedius bring the number of known cephalosporinase sequences from the genus Enterobacter to seven. Expression in Escherichia coli of the ampC genes from E. asburiae, E. hormaechei and E. intermedius established the functional nature of these genes. ampC from E. asburiae shows 96.5% identity to bla(ACT-1) encoding a plasmid-borne cephalosporinase previously believed to derive from Enterobacter cloacae. The reassignment of ACT-1 ancestry to E. asburiae is confirmed by the 95.5% identity between ampR upstream of bla(ACT-1) and ampR from E. asburiae.