Non-O1, non-O139 Vibrio cholerae bacteraemia: case report and literature review.

Non-O1, non-O139 Vibrio cholerae (NOVC) are increasingly frequently observed ubiquitous microorganisms occasionally responsible for intestinal and extra-intestinal infections. Most cases involve self-limiting gastroenteritis or ear and wound infections in immunocompetent patients. Bacteraemia, which have been described in patients with predisposing factors, are rare and poorly known, both on the clinical and therapeutic aspects. We describe a case of NOVC bacteraemia and a systematic literature review in PubMed conducted up to November 2014 using a combination of the following search terms: "Vibrio cholerae non-O1" and "bacter(a)emia". The case was a 70 year-old healthy male subject returning from Senegal and suffering from NOVC bacteraemia associated with liver abscesses. Disease evolution was favourable after 2 months' therapy (ceftriaxone then ciprofloxacin). Three hundred and fifty cases of NOVC bacteraemia have been identified in the literature. The majority of patients were male (77 %), with a median age of 56 years and presenting with predisposing conditions (96 %), such as cirrhosis (55 %) or malignant disease (20 %). Diarrhoea was inconstant (42 %). Mortality was 33 %. The source of infection, identified in only 25 % of cases, was seafood consumption (54 %) or contaminated water (30 %). Practitioners should be aware of these infections, in order to warn patients with predisposing conditions, on the risk of ingesting raw or undercooked seafood or bathing in potentially infected waters.

In vitro antimicrobial susceptibility of Helcococcus kunzii and molecular analysis of macrolide and tetracycline resistance.

Thanks to the recent advent of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) technology, Helcococcus kunzii is now easily identifiable and considered as an opportunistic pathogen. However, data about antimicrobial susceptibilities remain very limited. The aim of the study was, then, to assess its in vitro susceptibility to 18 antimicrobial agents and to investigate the genetic basis of macrolide and tetracycline resistance. Thirty-nine human clinical isolates of H. kunzii collected from 2008 to 2013 were studied, as well as the type strain ATCC 51366(T). Minimum inhibitory concentrations (MICs) of penicillin G, amoxicillin, cefotaxime, imipenem, gentamicin, erythromycin, clindamycin, quinupristin-dalfopristin, ciprofloxacin, levofloxacin, tetracycline, tigecycline, vancomycin, teicoplanin, linezolid, daptomycin, cotrimoxazole and rifampin were determined by the microdilution method. Screening for macrolide [erm(A) including erm(TR), erm(B), erm(C), erm(F), erm(T), erm(X), msr(A) and mef(A)] and tetracycline [tet(L), tet(M) and tet(O)] resistance genes was performed, as well as the detection of mutations in 23S rRNA. Except for one strain resistant to cefotaxime, all strains were categorised as susceptible to ß-lactams, glycopeptides, linezolid, daptomycin and tigecycline. Whereas ciprofloxacin and gentamicin exhibited limited activity, 95% of strains were categorised as susceptible to levofloxacin. Concerning erythromycin, a bimodal distribution was observed, with 29 'wild-type' strains (MICs from 0.25 to 2 mg/L) and 11 'resistant' strains (MICs ≥ 256 mg/L), including ten harbouring erm(TR). Two isolates exhibited acquired tetracycline resistance (MICs of 16 mg/L) by the production of tet(M). This large study on the in vitro antimicrobial susceptibility of H. kunzii suggests that ß-lactams (especially penicillins) should be preferred for the treatment.

Non-carbapenem therapy of urinary tract infections caused by extended-spectrum ß-lactamase-producing Enterobacteriaceae.

PURPOSE: We determined the prevalence of ESBL Enterobacteriaceae in urinary tract infections among inpatients, identified risk factors of acquisition, and evaluated the effectiveness of alternatives to carbapenems. METHODS: The clinical, microbiological, and therapeutic data as well as the outcomes were recorded for all ESBL-E positive urine samples for three months. RESULTS: Thirty-one (4%) of the 762 Enterobacteriaceae positive cultures were ESBL producers. The predisposing conditions for being infected with those strains were: immunodepression (61%), recent hospitalization (52%), recent antibiotic therapy (52%), and urinary catheterization (61%). 19% of infections were community acquired. The seven cases of acute pyelonephritis and five of prostatitis were treated with piperacillin-tazobactam (5), fluoroquinolones (4), ceftazidime (2), or carbapenems (only 1) after specialized advice. Four (33%) patients relapsed at week 10: three were immunodepressed and three presented with bacteremia. CONCLUSIONS: Alternatives to carbapenems (especially piperacillin-tazobactam) seem to be a good option for non-bacteremic UTI in immunocompetent patients.

An information campaign on aminoglycosides use during septic shock failed to improve the quality of care.

BACKGROUND: Septic shock remains a major cause of death in intensive care units (ICU) and an inappropriate antibiotic regimen worsens the prognosis. The aim of the study was to assess the impact of an information campaign on modalities of prescription of aminoglycosides in septic shock. STUDY DESIGN: A prospective observational study. METHODS: Consecutive septic shock patients admitted to the surgical ICU over a 2-year period were included. An information campaign allowed to differentiate between a pre- (P1) and a post- (P2) interventional period. The campaign clarified the rules and requirements for pharmacological monitoring of aminoglycosides. The main objective was to increase the rate of prescription of peak serum aminoglycoside following the first intravenous injection. RESULTS: One hundred and forty-eight patients (P1=76 and P2=72) were finally included into the study. Similar clinical characteristics were observed during both periods. The rate of prescription of peak serum aminoglycoside following the first injection was performed in 49% (P1) versus 65% (P2), P=0.09. The length of stay in ICU was 16 days [extremes: 1-74] (P1) versus 17 days [extremes: 1-133] (P2) (P=0.84). Inhospital mortality was 28% (P1) versus 26% (P2), P=0.86. CONCLUSIONS: An information campaign describing the modalities of prescription of aminoglycosides in septic shock failed to improve medical practices and patient outcomes. A mobile team of antibiotics could be useful in daily practice.

[Vancomycin, what else?]. / Faut-il abandonner la vancomycine?

Vancomycin and teicoplanin are glycopeptidic antibiotics that are used for many years in infections due to methicillin-resistant Staphylococcus aureus (MRSA). Nephrotoxicity of vancomycin and a slow clinical efficacy lead to discuss alternatives. Glycopeptides are less active than oxacillin against staphylococci susceptible to methicillin and should be reserved for infections due to MRSA. MRSA prevalence has decreased for several years in pediatrics but may remain frequent in neonatal intensive care units. Coagulase-negative staphylococci are a major cause of infections in neonates and are often resistant to methicillin. Community-acquired MRSA that produce Panton-Valentine leucocidin and are responsible for severe cutaneous infections and for rare severe necrotizing pneumonia in children spread over several years but their frequency remains low in France (2-4 % of MRSA). A new community-acquired MRSA clone, producer of toxic shock staphylococcal toxin is increasingly isolated. Efficacy of vancomycin against staphylococci is inversely correlated with MIC. MIC should be determined in severe infections and a seric concentration of vancomycin of 8 times the MIC should be reached as a target value. Glycopeptide resistance is rare in Staphylococcus aureus, but not that to teicoplanin in coagulase-negative staphylococci. MRSA remain currently susceptible to several antibiotics in addition to glycopeptides. Linezolid and daptomycin, recently introduced in therapy, have no indication in children but may have an interest.

Factors associated with emergence of pristinamycin-resistant Staphylococcus aureus in a dermatology department: a case-control study.

BACKGROUND: Pristinamycin is used for the treatment of Staphylococcus aureus skin infection. Staphylococcus aureus pristinamycin resistance is usually low. The frequency of pristinamycin-resistant S. aureus (PRSA) increased in the Caen University Hospital dermatology department from 1% in 1998 to >11% in 1999-2002. OBJECTIVES: This study aimed to identify the factors associated with PRSA acquisition. METHODS: Incidences of PRSA and pristinamycin consumption were calculated for the dermatology department and for the rest of the hospital from 1997 to 2007. Individual factors of PRSA acquisition in the dermatology department from 2000 to 2001 were analysed in a retrospective case-control study including 23 cases of PRSA skin colonization or infection and 46 controls with pristinamycin-susceptible S. aureus. Clonal relatedness of isolates was analysed by pulsed-field gel electrophoresis and pristinamycin resistance genes were detected by polymerase chain reaction. Conditional logistic regression was performed to analyse the relationship between pristinamycin resistance and epidemiological and microbiological data. RESULTS: PRSA frequency and pristinamycin consumption were significantly higher in the dermatology department than in other hospital departments. Two epidemic clones of two and six isolates were found for periods of 1 and 2 months, respectively. Thirteen of the 23 PRSA isolates (57%), including all isolates of the two epidemic clones, were found 48 h after the hospitalization or later. PRSA was associated with pristinamycin use during the previous year [odds ratio (OR) 5.60, 95% confidence interval (CI) 1.41-22.22], cumulative use of antibiotics exceeding 1 week during the previous year (OR 4.63, 95% CI 1.47-14.54) and methicillin resistance (OR 6.35, 95% CI 1.38-29.15). CONCLUSIONS: Results suggest that antimicrobial selective pressure and microbial cross-transmission are involved in PRSA acquisition.

[Update on antimicrobial chemotherapy]. / Quelles nouveautés en antibiothérapie?

There is a constant need for new antibacterial agents because of the unavoidable development of bacterial resistance that follows the introduction of antibiotics in clinical practice. As observed in many fields, innovation generally comes by series. For instance, a wide variety of broad-spectrum antibacterial agents became available between the 1970s and the 1990s, such as cephalosporins, penicillin/beta-lactamase inhibitor combinations, carbapenems, and fluoroquinolones. Over the last 2 decades, the arrival of new antibacterial drugs on the market has dramatically slowed, leaving a frequent gap between isolation of resistant pathogens and effective treatment options. In fact, many pharmaceutical companies focused on the development of narrow-spectrum antibiotics targeted at multidrug-resistant Gram-positive bacteria (e.g. methicillin-resistant Staphylococcus aureus, penicillin resistant Streptococcus pneumoniae, and vancomycin-resistant Enterococcus faecium). Therefore, multidrug-resistant Gram-negative bacteria (e.g. extended-spectrum beta-lactamase-producing Enterobacteriaceae, carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii) recently emerged and rapidly spread worldwide. Even if some molecules were developed, new molecules for infections caused by these multidrug-resistant Gram-negative bacteria remain remarkably scarce compared to those for Gram-positive infections. This review summarises the major microbiological, pharmacological, and clinical properties of systemic antibiotics recently marketed in France (i.e. linezolid, daptomycin, tigecycline, ertapenem, and doripenem) as well as those of antibacterial drugs currently in development (i.e. ceftobiprole, ceftaroline, dalbavancin, telavancin, oritavancin, iclaprim, and ramoplanin) or available in other countries (i.e. garenoxacin, sitafloxacin, and temocillin).

Catalase-negative Staphylococcus aureus strain with point mutations in the katA gene.

Methicillin-susceptible catalase-negative Staphylococcus aureus strain UCN61 was isolated from an arterial leg ulcer. The deduced sequence of the structural katA gene for the catalase was 99% identical to those of other S. aureus strains. Two mutations were identified in katA from S. aureus UCN61, including one leading to a substitution of key histidine 58 by a tyrosine.