Virulence of beta-hemolytic streptococci in infective endocarditis.

BACKGROUND: Streptococci involved in infective endocarditis (IE) primarily comprise alpha- or non-hemolytic streptococci (ANHS). Moreover, beta-hemolytic streptococci (BHS) can be involved, and guidelines recommend the addition of gentamicin for the first 2 weeks of treatment and the consideration of early surgery in such cases. This study compared the morbidity and mortality associated with IE depending on the microorganisms involved (BHS, ANHS, staphylococci, and enterococci). METHODS: We conducted a retrospective observational study between 2012 and 2017 in a single hospital in France. The endpoints were overall in-hospital mortality, 1-year mortality and the occurrence of complications. RESULTS: We analyzed 316 episodes of definite IE including 150 (38%), 96 (25%), 46 (12%), and 24 cases (6%) of staphylococcal, ANHS, enterococcal, and BHS IE, respectively. In-hospital mortality was significantly higher in the staphylococcal (n = 40; 26.7%) and BHS groups (n = 6; 25.0%) than in the ANHS (n = 9; 9.4%) and enterococcal groups (n = 5; 10.9%) (all p < 0.01). The rates of septic shock and cerebral emboli were also higher in the BHS group than in the ANHS group [n = 7 (29.2%) vs. n = 3 (3.1%), p < 0.001; n = 7 (29.2%) vs. n = 12 (12.5%); p = 0.05, respectively]. CONCLUSION: This study confirmed that BHS IE has a more severe prognosis than ANHS IE. The virulence of BHS may be similar to that of staphylococci, justifying increased monitoring of these patients and more 'aggressive' treatments such as early surgery.

Impact of Setting up an "Endocarditis Team" on the Management of Infective Endocarditis.

BACKGROUND: Infective endocarditis (IE) remains a severe disease with a high mortality rate. Therefore, guidelines encourage the setup of a multidisciplinary group in reference centers. The present study evaluated the impact of this "Endocarditis Team" (ET). METHODS: We conducted a monocentric observational study at Strasbourg University Hospital, Strasbourg, France, between 2012 and 2017. The primary end point was in-hospital mortality. Secondary end points were 6-month and 1-year mortality, surgery rate, time to surgical procedure, duration of effective antibiotic therapy, length of in-hospital stay, and sequelae. We also assessed predictors of in-hospital mortality. RESULTS: We analyzed 391 episodes of IE. In the post-ET period, there was a nonsignificant decrease in in-hospital mortality (20.3% vs 14.7%, respectively; P = .27) and sequelae, along with a significant reduction in time to surgery (16.4 vs 10.3 days, respectively; P = .049), duration of antibiotic therapy (55.2 vs 47.2 days, respectively; P < .001), and length of in-hospital stay (40.6 vs 31.9 days, respectively; P < .01). In a multivariate analysis, the post-ET period was positively associated with survival (odds ratio, 0.45; 95% confidence interval, 0.20-0.96; P = .048). CONCLUSIONS: This multidisciplinary approach exerted a positive impact on the management of IE and should be considered in all hospitals managing IE.

Culture with BACTEC Peds Plus bottle compared with conventional media for the detection of bacteria in tissue samples from orthopedic surgery.

We evaluated the performance of the BACTEC Peds Plus bottles for the detection of bacteria in 186 tissue samples obtained from orthopedic infections. BACTEC Peds Plus bottles led to bacterial detection in 69% of these samples against less than 53% for each of the other types of conventional media (P < 0.05). For some patients, the time of detection of pathogens was lower with the BACTEC Peds Plus bottles than with the conventional media.

Infectious crystalline keratopathy caused by Streptococcus Abiotrophia defectiva.

PURPOSE: To report the first case of Streptococcus Abiotrophia defectiva-associated crystalline keratopathy. METHODS: An 83-year-old woman underwent penetrating keratoplasty for pseudophakic bullous keratopathy in the OD. Ten months after surgery, the patient presented with decreased visual acuity in the OD. Slit-lamp examination showed crystalline keratopathy. Corneal scrapings were negative, and the patient was treated empirically with 2 fortified antibiotics (ciprofloxacin and vancomycin). Despite these treatments, the surface of the infiltrate increased and corneal regrafting was performed 6 weeks later. The excised prior graft was evaluated microbiologically [culture and polymerase chain reaction (PCR)] and histopathologically. RESULTS: In the explanted corneal graft, cultures grew Streptococcus A. defectiva, and its DNA was demonstrated by broad-range PCR (16S ribosomal DNA). CONCLUSIONS: A. defectiva can be a causative organism of infectious crystalline keratopathy. Risk factors may include long-term corticosteroid use and prior corneal transplantation. The present case confirms that PCR can be a useful technique in the diagnosis of deep infectious keratitis.

The beta-lactam-sensitive D,D-carboxypeptidase activity of Pbp4 controls the L,D and D,D transpeptidation pathways in Corynebacterium jeikeium.

Corynebacterium jeikeium is an emerging nosocomial pathogen responsible for vascular catheters infections, prosthetic endocarditis and septicemia. The treatment of C. jeikeium infections is complicated by the multiresistance of clinical isolates to antibiotics, in particular to beta-lactams, the most broadly used class of antibiotics. To gain insight into the mechanism of beta-lactam resistance, we have determined the structure of the peptidoglycan and shown that C. jeikeium has the dual capacity to catalyse formation of cross-links generated by transpeptidases of the d,d and l,d specificities. Two ampicillin-insensitive cross-linking enzymes were identified, Ldt(Cjk1), a member of the active site cysteine l,d-transpeptidase family, and Pbp2c, a low-affinity class B penicillin-binding protein (PBP). In the absence of beta-lactam, the PBPs and the l,d-transpeptidase contributed to the formation of 62% and 38% of the cross-links respectively. Although Ldt(Cjk1) and Pbp2C were not inhibited by ampicillin, the participation of the l,d-transpeptidase to peptidoglycan cross-linking decreased in the presence of the drug. The specificity of Ldt(Cjk1) for acyl donors containing a tetrapeptide stem accounts for this effect of ampicillin since the essential substrate of Ldt(Cjk1) was produced by an ampicillin-sensitive d,d-carboxypeptidase (Pbp4(Cjk)). Acquisition and mutational alterations of pbp2C accounted for high-level beta-lactam resistance in C. jeikeium.

Aeromonas tecta sp. nov., isolated from clinical and environmental sources.

Five Aeromonas strains, isolated from both clinical and environmental sources and characterized by a polyphasic approach, including phylogenetic analysis derived from gyrB, rpoD, and 16S rRNA gene sequencing, as well as DNA-DNA hybridization, extensive biochemical and antibiotic susceptibility tests, were recognized as members of an unknown, or undescribed, Aeromonas species. These "Aeromonas eucrenophila-like" strains were closely related to the species A. eucrenophila and Aeromonas encheleia, but they were negative for indole and acid from glycerol tests. Therefore, based on the results of the phylogenetic analyses and DNA-DNA pairing data of these strains, a novel species of the genus Aeromonas is described, for which the name Aeromonas tecta is proposed with isolate F518(T) (CECT7082(T), DSM17300(T), MDC91(T)) as the type strain.

Risk of gastric cancer after Roux-en-Y gastric bypass.

OBJECTIVE: To evaluate the risk of gastric cancer after Roux-en-Y gastric bypass (RYGB). DESIGN: Rats randomly underwent 1 of the following: RYGB, duodenojejunal bypass (DJB), or a sham operation. Postoperatively, rats underwent a protocol of cancer induction by means of both continuous (200 ppm in tap water for 16 weeks) and intermittent (50-mg/kg intraesophageal injection, once a week, for 12 weeks) administration of N-methyl-N-nitrosourea. SETTING: Institut de Recherche Contre les Canceurs de l'Appareil Digestif-European Institute of Telesurgery. STUDY ANIMALS: Fifty-five Fischer 344 rats. MAIN OUTCOME MEASURES: Seventeen weeks after the operation, we performed a pathologic examination of the whole stomach in all animals to assess for the presence of cancer and/or premalignant lesions. Bilirubin concentration, gastric bacterial flora, and any other pathologic findings were also recorded. RESULTS: In rats in the sham and DJB groups, the incidence of gastric cancer was 85% and 75%, respectively (P = .63), whereas only 23% of rats in the RYGB group developed gastric cancer (4-fold reduction; P = .002). The remnant stomach of rats in the RYGB group also showed a lower bilirubin concentration (P < .01) and a lower bacterial count (P < .05) compared with both the DJB and sham groups. CONCLUSIONS: This study shows that RYGB reduces the risk of gastric cancer in an experimental model of dietary-induced carcinogenesis. Lack of direct contact with carcinogens, lower bile reflux, and a lower bacteria concentration in the gastric content may be responsible for these observations. These data suggest that RYGB may be a safe option for the treatment of morbid obesity even in areas with high gastric cancer incidence.

Corynebacterium hansenii sp. nov., an alpha-glucosidase-negative bacterium related to Corynebacterium xerosis.

A novel strain, C-138(T), belonging to the genus Corynebacterium was isolated from a severe thigh liposarcoma infection and its differentiation from Corynebacterium xerosis and Corynebacterium freneyi is described. Analysis of 16S rRNA gene sequences, rpoB sequences and the PCR profile of the 16S-23S spacer regions was not conclusive enough to differentiate strain C-138(T) from C. xerosis and C. freneyi. However, according to DNA-DNA hybridization data, strain C-138(T) constitutes a member of a distinct novel species. It can be differentiated from strains of C. xerosis and C. freneyi by colony morphology, the absence of alpha-glucosidase and some biochemical characteristics such as glucose fermentation at 42 degrees C and carbon assimilation substrates. The name Corynebacterium hansenii sp. nov. is proposed for this novel species; the type strain is C-138(T) (=CIP 108444(T)=CCUG 53252(T)).

Isolation of Helcococcus kunzii from a post-surgical foot abscess.

We report here a case in which a strain of Helcococcus kunzii was isolated from a foot abscess, in an immunocompetent patient, after surgery for metatarsal fracture. Correct species identification of the strain was readily obtained on the basis of morphological and biochemical features, together with 16S rRNA analysis. This case demonstrates that this species should be considered a potential pathogen in patients with no underlying disease.