Clostridium difficile bacteremia: Report of two cases in French hospitals and comprehensive review of the literature.

We report two cases of bacteremia due to Clostridium difficile from two French hospitals. The first patient with previously diagnosed rectal carcinoma underwent courses of chemotherapy, and antimicrobial treatment, and survived the C. difficile bacteremia. The second patient with colon perforation and newly diagnosed lung cancer underwent antimicrobial treatment in an ICU but died shortly after the episode of C. difficile bacteremia. A review of the literature allowed the identification of 137 cases of bacteremia between July 1962 and November 2016. Advanced age, gastro-intestinal disruption, severe underlying diseases and antimicrobial exposure were the major risk factors for C. difficile bacteremia. Antimicrobial therapy was primarily based on metronidazole and/or vancomycin. The crude mortality rate was 35% (21/60).

Diversity and functionality of plasmid-borne VagCD toxin-antitoxin systems of Klebsiella pneumoniae.

Objectives: To explore the VagCD toxin-antitoxin (TA) systems encoded on plasmids in multiresistant Klebsiella pneumoniae strains. Methods: Previously sequenced K. pneumoniae plasmids were used for in silico analysis and a collection of 63 resistant K. pneumoniae strains was used for epidemiological study. Functional analysis was done after separate cloning of the toxin gene under the control of the arabinose-inducible promoter of pBAD43 and of the antitoxin gene under the control of the constitutive promoter of pUC19. Results: In silico , two types of VagCD systems, VagCD1 and VagCD2, encoded on K. pneumoniae plasmids could be distinguished, 15% carrying one of these TA systems. Moreover, in a collection of antibiotic-resistant K. pneumoniae strains including ESBL or carbapenemase producers, 17.5% of isolates were found to harbour a VagCD TA system. VagCD1 and VagCD2 were proved functional TA systems, with VagD the toxin and VagC its antitoxin, not only in K. pneumoniae but also in Escherichia coli and other Enterobacteriaceae. Toxin expression was found to induce a significant decrease in a bacterial population resulting from both bactericidal and bacteriostatic effects. Conclusions: The vagCD genes of K. pneumoniae encode a functional broad-spectrum TA system and are conserved on the large multiple antibiotic resistance-conferring plasmids in this species.

Quantitative evaluation of extended-spectrum ß-lactamase-producing Escherichia coli strains in the wastewater of a French teaching hospital and relation to patient strain.

BACKGROUND: Extended-spectrum ß-lactamase-producing Escherichia coli has become ubiquitous and has been reported in diverse ecosystems. We evaluated the potential impact of post-acute and long-term healthcare activities on the environment by quantifying ESBL-producing Enterobacteriaceae in wastewaters of a French geriatric hospital. METHODS: We collected wastewater specimens representative of one-day efflux immediately before the connection with the municipal sewer pipe. The sample was processed following two different methods: dilution-filtration method and concentration method and was screened for ESBL-producing Enterobacteriaceae using selective media. ESBL E. coli strains were quantified, screened for ESBL genes and compared with ESBL strains isolated from patients present in the building at the time of wastewater collection, using molecular methods. RESULTS: Six distinct environmental ESBL E. coli clusters were identified, two of them related to patient strains. The concentrations in hospital wastewater of these strains ranged from 2.5 × 10(4) to 10(6) UFC/L. CONCLUSIONS: Our results demonstrate that the presence of ESBL E. coli patients leads to a dissemination of ESBL E. coli in the environment and highlights the need to improve excreta and wastewater policy in hospitals.

Klebsiella pneumoniae necrotizing fasciitis of the leg in an elderly French woman.

Klebsiella pneumoniae necrotizing fasciitis is a rare infection in regions outside of Asia. Here, we present a case of necrotizing fasciitis of the leg caused by K. pneumoniae in a 92-year-old French woman hospitalized in a geriatric rehabilitation unit. The patient initially presented with dermohypodermitis of the leg that developed from a dirty wound following a fall. A few hours later, this painful injury extended to the entire lower limb, with purplish discoloration of the skin, bullae, and necrosis. Septic shock rapidly appeared and the patient died 9 hours after the onset of symptoms. The patient was Caucasian, with no history of travel to Asia or any underlying disease. Computed tomography revealed no infectious metastatic loci. Blood cultures showed growth of capsular serotype K2 K. pneumoniae strains with virulence factors RmpA, yersiniabactin and aerobactin. This rare and fatal case of necrotizing fasciitis caused by a virulent strain of K. pneumoniae occurred in a hospitalized elderly woman without risk factors. Clinicians and geriatricians in particular should be aware of this important albeit unusual differential diagnosis.

Complete nucleotide sequence of two multidrug-resistant IncR plasmids from Klebsiella pneumoniae.

We report here the complete nucleotide sequence of two IncR replicons encoding multidrug resistance determinants, including ß-lactam (blaDHA-1, blaSHV-12), aminoglycoside (aphA1, strA, strB), and fluoroquinolone (qnrB4, aac6'-1b-cr) resistance genes. The plasmids have backbones that are similar to each other, including the replication and stability systems, and contain a wide variety of transposable elements carrying known antibiotic resistance genes. This study confirms the increasing clinical importance of IncR replicons as resistance gene carriers.

Complete nucleotide sequence of the first KPC-2- and SHV-12-encoding IncX plasmid, pKpS90, from Klebsiella pneumoniae.

We report the complete nucleotide sequence of the pKpS90 plasmid, carrying the bla(KPC-2) and bla(SHV-12) genes. This plasmid was isolated from a sequence type 258 (ST258) Klebsiella pneumoniae strain responsible for an outbreak in a French university hospital in 2009. pKpS90 is a 53,286-bp plasmid that belongs to the IncX incompatibility group. pKpS90 consists of a backbone from IncX plasmids, in which the KPC-2-encoding Tn4401 transposon and a bla(SHV-12)-encoding region have been inserted.

Complete nucleotide sequence of the large conjugative pTC2 multireplicon plasmid encoding the VIM-1 metallo-ß-lactamase.

OBJECTIVES: To determine the complete nucleotide sequence of the VIM-1-encoding plasmid pTC2, which was isolated from a Greek Providencia stuartii multiresistant strain. METHODS: The pTC2 plasmid was extracted and sequenced using shotgun and 3 kb paired-end DNA libraries and a 454 sequencing approach. Following assembly into a unique scaffold, gaps were closed by PCR followed by Sanger DNA sequencing. Gene predictions and annotations were performed using the CAAT-Box tool and the Conserved Domain Search service. Sequence comparisons were performed using the Artemis Comparison Tool. RESULTS: Plasmid pTC2 (180,184 bp) was found to be a multireplicon plasmid (IncA/C and IncR), with a large IncA/C backbone and a mosaic multidrug resistance (MDR) region, in which was inserted a 13 kb IncR fragment. Gene annotation allowed the identification of a complete IncA/C-type transfer system and of several putative maintenance modules, both on the IncA/C backbone and on the IncR fragment. The complex MDR region contained 9 insertion sequences (7 IS26, 1 IS1 and 1 IS6100), 10 resistance genes and a mercury resistance operon integrated into unit transposons, composite transposons or integrons. CONCLUSIONS: The pTC2 combines a broad host range, transfer and maintenance capacities, plasticity of the MDR region and a wide variety of resistance genes, properties that may contribute to the spreading of resistance determinants.

Phylogenetic distribution of CTX-M- and non-extended-spectrum-ß-lactamase-producing Escherichia coli isolates: group B2 isolates, except clone ST131, rarely produce CTX-M enzymes.

Escherichia coli is the species most frequently associated with clinical infections by extended-spectrum-ß-lactamase (ESBL)-producing isolates, with the CTX-M ESBL enzymes being predominant and found in genetically diverse E. coli isolates. The main objective of this study was to compare, on the basis of a case-control design, the phylogenetic diversity of 152 CTX-M-producing and 152 non-ESBL-producing clinical E. coli isolates. Multilocus sequence typing revealed that even though CTX-M enzymes were largely disseminated across the diversity of E. coli isolates, phylogenetic group B2 showed a particularly heterogeneous situation. First, clone ST131 of group B2 was strongly associated with CTX-M production (55 [79%] of 70 isolates), with CTX-M-15 being predominant. Second, the remaining members of group B2 were significantly less frequently associated with CTX-M production (9 [12%] of 75) than E. coli phylogenetic groups A, B1, and D (88 [55%] of 159). CTX-M-producing ST131 E. coli isolates were significantly more frequent in patients hospitalized in geriatric wards or long-term care facilities. Besides, the non-ESBL ST131 isolates significantly more frequently showed resistance to penicillins than the non-ESBL, non-ST131 isolates did. In conclusion, the present study emphasizes the particular antimicrobial resistance and epidemiologic characteristics of clone ST131 within group B2, which could result from the higher antibiotic exposure of this clone, as it is the predominant clone of group B2 carried in the human gut.

Patient's origin and lifestyle associated with CTX-M-producing Escherichia coli: a case-control-control study.

BACKGROUND: Global dissemination of Escherichia coli producing CTX-M extended-spectrum ß-lactamases (ESBL) is a public health concern. The aim of the study was to determine factors associated with CTX-M- producing E. coli infections among patients hospitalised in the Assistance Publique-Hôpitaux de Paris, the largest hospital system in France (23 000 beds), through a prospective case-control-control study. METHODS/PRINCIPAL FINDINGS: From November 2008 to June 2009, 152 inpatients with a clinical sample positive for CTX-M-producing E. coli (cases), 152 inpatients with a clinical sample positive for non ESBL-producing E. coli on the day or within the three days following case detection (controls C1), and 152 inpatients with culture-negative clinical samples since the beginning of hospitalisation and until three days after case detection (controls C2) were included in ten hospitals of the Paris area. Factors studied were related to patient's origin, lifestyle and medical history as well as care during hospitalisation. Those independently associated with CTX-M-producing E. coli were determined. Three independent factors were common to the two case-control comparisons: birth outside of Europe (cases vs C1: OR(1) = 2.4; 95%CI = [1.3-4.5] and cases vs C2: OR(2) = 3.1; 95%CI = [1.4-7.0]), chronic infections (OR(1) = 2.9; 95%CI = [1.3-6.9] and OR(2) = 8.7; 95%CI = [2.0-39.7]), and antibiotic treatment between hospital admission and inclusion (OR(1) = 2.0; 95%CI = [1.0-3.8] and OR(2) = 3.3; 95%CI = [1.5-7.2]). Cases were also more likely to be (i) functionally dependent before hospitalisation than C2 (OR(2) = 7.0; 95%CI = [2.1-23.5]) and (ii) living in collective housing before hospitalisation than C2 (OR(2) = 15.2; 95%CI = [1.8-130.7]) when CTX-M-producing E. coli was present at admission. CONCLUSION: For the first time, patient's origin and lifestyle were demonstrated to be independently associated with isolation of CTX-M-producing E. coli, in addition to health care-related factors.

Sensitive and specific phenotypic assay for metallo-beta-lactamase detection in Enterobacteria by use of a moxalactam disk supplemented with EDTA.

Moxalactam is highly hydrolyzed by plasmid-mediated metallo-ß-lactamases (MBLs), whereas it is poorly inactivated by serine-active carbapenemases. This study demonstrated that moxalactam resistance constituted an effective screen for MBL expression in enterobacteria, which could be confirmed, even in low-MBL-producing isolates, by a disk potentiation test using moxalactam and EDTA.

Endocarditis due to Neisseria bacilliformis in a patient with a bicuspid aortic valve.

We report a case of endocarditis due to the rod-shaped Neisseria species Neisseria bacilliformis. The phenotypic characterization of this recently characterized bacteria is difficult, and the identification requires the sequencing of the 16S rRNA gene. The resolution of the disease was complete after appropriate antibiotic therapy, and surgery was not required.