Antibioprophylaxis in surgery and interventional medicine (adult patients). Update 2017.

Infection is a risk for any intervention. In surgery, for example, pathogenic bacteria are found in more than 90% of operative wounds during closure. This exists whatever the surgical technique and whatever the environment (the laminar flow does not entirely eliminate this risk). These bacteria are few in number but can proliferate. They find in the operative wound a favourable environment (haematoma, ischaemia, modification of oxido-reduction potential...) and the intervention induces anomalies of the immune defences. In the case of the installation of foreign material, the risk is increased. The objective of antibiotic prophylaxis (ABP) is to prevent bacterial growth in order to reduce the risk of infection at the site of the intervention. The preoperative consultation represents a privileged moment to decide on the prescription of a ABP. It is possible to define the type of intervention planned, the associated risk of infection (and therefore the necessity or not of ABP), the time of prescription before surgery and any allergic antecedents which may modify the choice of the selected antibiotic molecule.

Continuous high-dose vancomycin combination therapy for methicillin-resistant staphylococcal prosthetic hip infection: a prospective cohort study.

Few data are available on treatment and outcome of methicillin-resistant (MR) staphylococcal prosthetic joint infections. Vancomycin remains the treatment of choice for these infections, but its efficacy and safety in bone-and-joint infections are insufficiently documented. We conducted a prospective cohort study on 60 patients treated between November 2002 and December 2008 for chronic MR staphylococcal (44 S. epidermidis, nine other coagulase-negative Staphylococcus and seven S. aureus) prosthetic hip infections (PHIs). Twenty-two patients had previously undergone surgery for their PHI and 21 had previously received antibiotics. All patients had surgery (exchange arthroplasty for 58 patients, resection arthroplasty for two) and received an antibiotic regimen combining high-dose continuous intravenous vancomycin infusion (target serum concentration 30-40 mg/L) with another antibiotic for 6 weeks, followed by an additional 6 weeks of oral intake. Two years after surgery, infection was considered cured in 41 (68%) patients and only two relapses occurred after one-stage exchange arthroplasty. Nineteen (32%) patients experienced nephrotoxicity that was generally mild (RIFLE class R for 14 patients, class I for four patients and class F for one patient) and most often reversible. Continuous high-dose intravenous vancomycin combination therapy is an effective, feasible and reasonably safe treatment of chronic MR staphylococcal PHI.

In vitro antibacterial activity of ceftobiprole against clinical isolates from French teaching hospitals: proposition of zone diameter breakpoints.

The aims of this study were to determine the in vitro activity profile of ceftobiprole, a pyrrolidinone cephalosporin, against a large number of bacterial pathogens and to propose zone diameter breakpoints for clinical categorisation according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) minimum inhibitory concentration (MIC) breakpoints. MICs of ceftobiprole were determined by broth microdilution against 1548 clinical isolates collected in eight French hospitals. Disk diffusion testing was performed using 30 µg disks according to the method of the Comité de l'Antibiogramme de la Société Française de Microbiologie (CA-SFM). The in vitro activity of ceftobiprole, expressed by MIC(50/90) (MICs for 50% and 90% of the organisms, respectively) (mg/L), was as follows: meticillin-susceptible Staphylococcus aureus, 0.25/0.5; meticillin-resistant S. aureus (MRSA), 1/2; meticillin-susceptible coagulase-negative staphylococci (CoNS), 0.12/0.5; meticillin-resistant CoNS, 1/2; penicillin-susceptible Streptococcus pneumoniae, ≤ 0.008/0.03; penicillin-resistant S. pneumoniae, 0.12/0.5; viridans group streptococci, 0.03/0.12; ß-haemolytic streptococci, ≤ 0.008/0.016; Enterococcus faecalis, 0.25/1; Enterococcus faecium, 64/128; Enterobacteriaceae, 0.06/32; Pseudomonas aeruginosa, 4/16; Acinetobacter baumannii, 0.5/64; Haemophilus influenzae, 0.03/0.12; and Moraxella catarrhalis, 0.25/0.5. According to the regression curve, zone diameter breakpoints could be 28, 26, 24 and 22 mm for MICs of 0.5, 1, 2 and 4 mg/L respectively. In conclusion, this study confirms the potent in vitro activity of ceftobiprole against many Gram-positive bacteria, including MRSA but not E. faecium, whilst maintaining a Gram-negative spectrum similar to the advanced-generation cephalosporins such as cefepime. Thus ceftobiprole appears to be well suited for the empirical treatment of a variety of healthcare-associated infections.

In vitro antibacterial activity of doripenem against clinical isolates from French teaching hospitals: proposition of zone diameter breakpoints.

The aims of the study were to determine the in vitro activity of doripenem, a new carbapenem, against a large number of bacterial pathogens and to propose zone diameter breakpoints for clinical categorization in France according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) minimum inhibitory concentration (MIC) breakpoints. The MICs of doripenem were determined by the broth microdilution method against 1,547 clinical isolates from eight French hospitals. The disk diffusion test was performed (10-µg discs) according to the Comité de l'Antibiogramme de la Société Française de Microbiologie (CASFM) method. The MIC(50/90) (mg/L) values were as follows: methicillin-susceptible Staphylococcus aureus (MSSA) (0.03/0.25), methicillin-resistant Staphylococcus aureus (MRSA) (1/2), methicillin-susceptible coagulase-negative staphylococci (MSCoNS) (0.03/0.12), methicillin-resistant coagulase-negative staphylococci (MRCoNS) (2/8), Streptococcus pneumoniae (0.016/0.25), viridans group streptococci (0.016/2), ß-hemolytic streptococci (≤0.008/≤0.008), Enterococcus faecalis (2/4), Enterococcus faecium (128/>128), Enterobacteriaceae (0.06/0.25), Pseudomonas aeruginosa (0.5/8), Acinetobacter baumannii (0.25/2), Haemophilus influenzae (0.12/0.25), and Moraxella catarrhalis (0.03/0.06). According to the regression curve, the zone diameter breakpoints were 24 and 19 mm for MICs of 1 and 4 mg/L, respectively. This study confirms the potent in vitro activity of doripenem against Pseudomonas aeruginosa, Acinetobacter, Enterobacteriaceae, MSSA, MSCoNS, and respiratory pathogens. According to the EUCAST MIC breakpoints (mg/L) ≤1/>4 for Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter, and ≤1/>1 for streptococci, pneumococci, and Haemophilus, the zone diameter breakpoints could be (mm) ≥24/<19 and ≥24/<24, respectively.

[Pleural diffusion of amoxicillin 1 and vancomycin in patients treated for post-surgical empyema]. / Empyème après chirurgie d'exérèse pulmonaire: étude de la diffusion pleurale de l'amoxicilline et de la vancomycine.

INTRODUCTION: Treatment of post surgical thoracic empyema consists of chest tube drainage, antibiotic administration, and in some cases surgical lavage of infected spaces. Data in human on the diffusion of antibiotics in pleural cavity after post surgical empyema are lacking. METHODS: We studied on 9 patients with post surgical thoracic empyema (including 6 pneumonectomy) the diffusion of 2 antibiotics commonly used in this situation: amoxicillin (for 7 patients) and vancomycin (for 2 patients). Antibiotics concentrations were measured after at least 3 days of treatment (3-12 days), in order to reach a plateau concentration in the pleural space. RESULTS: The ratio pleural/plasma antibiotic concentration was 1.96 (range: 0.6-4.9). The pleural infection was cured for 8 on 9 patients. The last patients required thoracostomy, and the outcome was favorable after this procedure. CONCLUSION: That the penetration of amoxicillin and vancomycin in pleural space after post surgical empyema is good. Pleural antibiotics concentrations are in the majority of cases higher than plasmatic concentrations.

[Detection of nasal colonization methicillin-resistant Staphylococcus aureus: a prospective study comparing real-time genic amplification assay vs selective chromogenic media]. / Détection de la colonisation nasale de Staphylococcus aureus résistant à la méthicilline : étude prospective comparant l'amplification génique temps réel vs les milieux chromogènes sélectifs.

UNLABELLED: In contrast to "classical" genic amplification, real-time genic amplification can be performed in every laboratory without the need of sophisticated isolation procedures. Moreover, real-time genic amplification allows an early detection of meticillin resistant Staphylococcus aureus colonization, 2 hours compared to 1 or 2 days for culture. OBJECTIVE: In order to assess the feasibility on Smartcycler of the IDI-MRSA real-time genic amplification assay in comparison with chromogenic media. METHODS: A prospective study has been initiated in July 2004: nasal swabs were taken from patients entering the ICU, vascular surgery, diabetology and geriatry wards. During a 4 months period, 682 specimens have been obtained from 508 patients. RESULTS: Sixty-four (9.3%) patients were positive by genic amplification and selective agar culture (CHROMagar MRSA, MRSASelect and/or ORSAB), 19 (2.9%) were positive by genic amplification only (3 of these patients were under antibiotic treatment); 572 specimens remained negative by both methods. The sensitivity and specificity of this assay were 100% and 96% respectively with a positive predictive value of 70% and negative predictive value of 100%. Initially 82 nasal specimens were unresolved (12%). 38 were resolved following a freeze-thaw cycle. Thus, 44 (6.4%) were unresolved specimens. Comparison between CHROMagar MRSA and MRSASelect showed a good correlation for the detection at 24 hours (5.5% and 5.6% respectively). These two chromogenic media allowed a much better detection of MRSA than ORSAB medium within 24H. CONCLUSION: The results obtained by the early real-time genic amplification for the detection of meticillin resistant Staphylococcus aureus are promising. Despite 6.4% amplification failure, we consider that IDI-MRSA real-time genic amplification assay represents a significant breakthrough in the detection of colonization.

Monitoring of vancomycin serum levels for the treatment of staphylococcal infections.

Vancomycin serum concentrations were determined for 1,737 patients treated with either 2 x 1 g of vancomycin or 4 x 500 mg daily (780 patients), according to current nomograms, or by continuous infusion (957 patients) with a loading dose (1 g) and a total of 2-6 g daily. Trough serum concentrations were determined after 36-48 h. Adequate serum levels for the treatment of a normal methicillin-resistant Staphylococcus aureus (MRSA) and a glycopeptide-intermediate S. aureus (GISA) were observed in 81% and 20.9% of patients, respectively. The data support theoretical arguments that higher and more sustained serum levels of vancomycin, obtained by continuous infusion, may enhance clinical efficacy.

Total laparoscopic abdominal aortic aneurysms repair.

AIM: The aim of the study was to describe our experience of total laparoscopic abdominal aortic aneurysm (AAA) repair. METHODS: Between February 2002 and September 2004, we performed 49 total laparoscopic AAA repair in 45 men and 4 women. Median age was 73 years (range, 46-85 years). Median aneurysm size was 52 mm (range, 30-95 mm). ASA class of patients was II, III and IV in 16, 32 and 1 cases, respectively. We used the laparoscopic transperitoneal left retrocolic approach in 47 patients. Seven patients were operated via a tranperitoneal left retrorenal approach and one patient via a retroperitoneoscopic approach. RESULTS: We implanted tube grafts and bifurcated grafts in 19 and 30 patients, respectively. Median operative time was 290 min (range, 160-420 min). Median clamping time was 81.5 min (range, 35-230 min). Median blood loss was 1800 cc (range, 300-6900 cc). Mortality was 6.1% (3 patients). In our early experience, two patients died of myocardial infarction. The 3rd death was due to a multiple organ failure. Thirteen major non lethal postoperative complications were observed in 9 patients (18%). Four patients had local/vascular complications, which required reintervention (8%). Nasogastric tube is now removed at the end of procedure. Median duration of ileus, return to general diet, ambulation and hospital stay were 2, 3, 3 and 10 days. With a median follow-up of 19 months (range, 8-39 months), complete recovery with patent graft was observed in 44 patients. Two patients needed a crossover femoral graft for one iliac dissection and one graft limb occlusion. CONCLUSIONS: These results show that total laparoscopic AAA repair is feasible and worthwhile for patients once the learning curve is overcome. It remains technically demanding and a previous training in videoscopic sutures is essential. Initial learning curve in laparoscopic aortic surgery with aortoiliac occlusive lesions is preferable before to begin laparoscopic AAA repair.

False synergy between vancomycin and beta-lactams against glycopeptide-intermediate Staphylococcus aureus (GISA) caused by inappropriate testing methods.

The combination of vancomycin and beta-lactams is often considered synergistic and has been recommended for the treatment of glycopeptide-intermediate Staphylococcus aureus (GISA) infections. In this study, the combination of vancomycin or teicoplanin with different beta-lactams was tested. When using NaCl 4% w/v, for better expression of heterogeneous resistance to beta-lactams, with a longer (48-h) incubation period and a higher (10(7) CFU/mL) inoculum, the association of vancomycin with beta-lactams was antagonistic. However, a synergistic effect was observed for teicoplanin under the same conditions.

Vancomycin-resistant Staphylococcus aureus: no apocalypse now.

The number of reports concerning vancomycin-resistant Staphylococcus aureus is much higher than the number of true resistant strains or unexpected clinical failures. Many confounding factors, including inadequate serum levels, severely ill patients, foreign devices or undrained abscesses, are more likely to be responsible for the clinical failures than resistance to vancomycin.

Long-term results of cryopreserved arterial allograft reconstruction in infected prosthetic grafts and mycotic aneurysms of the abdominal aorta.

PURPOSE: This prospective, observational study determined the long-term outcome in patients with abdominal aortic infection (primary or prosthetic graft) who were treated with simultaneous aortic/graft excision and cryopreserved arterial allograft reconstruction. METHODS: From April 1992 to March 2000, patients with abdominal aortic infection underwent complete or partial excision of the infected aorta/prosthetic graft and cryopreserved arterial allograft reconstruction. Arterial allografts were harvested from multiple organ donors and cryopreserved at -80 degrees C without rate-controlled freezing. The patients were observed for survival, limb salvage, persistence and/or recurrence of infection, and allograft patency. The results were calculated with life-table methods. RESULTS: During the 8-year study period, 28 consecutive patients (27 men, 1 woman; mean age, 64 years) underwent treatment for abdominal aortic infection (23 graft infections, including 7 graft-enteric fistulas and 5 primary aortic infections). Allograft reconstruction was performed as an emergency procedure in 13 patients (46%). The mean follow-up period was 35.4 months (range, 6-101 months). The overall treatment-related mortality rate was 17.8% (17% for graft infection, 20% for primary aortic infection). The overall 3-year survival was 67%. There was no early or late amputation. There was no persistent or recurrent infection, and none of the patients received long-term (> 3 months) antibiotic therapy. Reoperation for allograft revision, excision, or replacement was necessary in four patients (17%) who were available for examination, with no reoperative perioperative death. The 3-year primary and secondary allograft patency rates were 81% and 96%, respectively. CONCLUSION: Our experience with cryopreserved arterial allograft in the management of abdominal aortic infection suggests that this technique seems to be a useful option for treating one of the most dreaded vascular complications.

New mutation in parE in a pneumococcal in vitro mutant resistant to fluoroquinolones.

For an in vitro mutant of Streptococcus pneumoniae selected on moxifloxacin four- to eightfold-increased MICs of new fluoroquinolones, only a twofold-increased MIC of ciprofloxacin, and a twofold-decreased MIC of novobiocin were observed. This phenotype was conferred by two mutations: Ser81Phe in GyrA and a novel undescribed His103Tyr mutation in ParE, outside the quinolone resistance-determining region, in the putative ATP-binding site of topoisomerase IV.

In vitro exchange of fluoroquinolone resistance determinants between Streptococcus pneumoniae and viridans streptococci and genomic organization of the parE-parC region in S. mitis.

Transfer of fluoroquinolone (FQ) resistance determinants between Streptococcus pneumoniae and viridans streptococci was explored by transformation in vitro. One-step FQ-resistant parC mutants were selected, and resistance could be transferred from DNA from S. oralis, S. mitis, S. sanguis, and S. constellatus to S. pneumoniae, with frequencies of 10(-3) to <10(-7) in correlation with the homologies of their quinolone resistance determining region sequences (95%, 91%, 85%, and 81%, respectively). Reciprocal transfers of mutated parC from DNA from S. pneumoniae to S. mitis and S. oralis were also observed. Simultaneous transfer of mutated parC and gyrA genes from S. mitis to S. pneumoniae yielded high-level-resistant pneumococcal transformants in one step at low frequencies. The parE-parC region of the type strain S. mitis 103335T had >90% homology with that of S. pneumoniae. The efficient interspecific transfer of quinolone resistance determinants in vitro leads us to anticipate their dissemination in the clinical setting.

In-vitro activity of levofloxacin, a new fluoroquinolone: evaluation against Haemophilus influenzae and Moraxella catarrhalis.

The in-vitro activity of levofloxacin was studied against 10 beta-lactamase-negative and 93 beta-lactamase-positive Moraxella catarrhalis isolates, and 65 beta-lactamase-negative and 35 beta-lactamase-positive Haemophilus influenzae isolates. The MICs of levofloxacin were determined by agar dilution on Mueller-Hinton agar (with the addition of 5% horse blood for M. catarrhalis) or on Haemophilus Test Medium for H. influenzae, and were compared with those of ofloxacin, ciprofloxacin and sparfloxacin, as well as pefloxacin and D-ofloxacin for M. catarrhalis. The fluoroquinolones showed similar activity against isolates of H. influenzae and M. catarrhalis, irrespective of beta-lactamase production. Levofloxacin (MIC50/90 0.06 mg/L) was 64 times more active against M. catarrhalis than D-ofloxacin (MIC50/90 4/8 mg/L) and twice as active as ofloxacin (MIC50/90 0.125 mg/L). Ciprofloxacin had an MIC50/90 of 0.03/0.06 mg/L and sparfloxacin showed an MIC50/90 of 0.015 mg/L against M. catarrhalis irrespective of the resistance phenotype of the isolates. Against H. influenzae, levofloxacin was twice as active as ofloxacin (MIC90 values 0.03 mg/L versus 0.06 mg/L), while the MIC90s of ciprofloxacin and sparfloxacin were both 0.015 mg/L. Our results therefore suggest that levofloxacin has potential for treating respiratory tract infections caused by H. influenzae and M. catarrhalis.

In-vitro antibacterial activity of levofloxacin against hospital isolates: a multicentre study.

The objective of this study was to evaluate the activity of the fluoroquinolone, levofloxacin, against hospital isolates of bacteria. MICs of levofloxacin were determined for 2154 strains by agar dilution. Breakpoints for susceptibility testing were calculated using the agar diffusion technique with 5 micrograms discs. The activity of levofloxacin against nalidixic acid- and pefloxacin-susceptible Enterobacteriaceae (n = 668) was higher (MIC50/90 0.06-0.12 mg/L) than previously reported for ofloxacin. As seen with other fluoroquinolones, this activity was reduced against nalidixic acid-resistant and pefloxacin-intermediate and -resistant strains (MIC 1-8 mg/L). MICs for Pseudomonas aeruginosa (n = 104) were between 0.12 and 128 mg/L. Levofloxacin had good activity against nalidixic acid- and pefloxacin-susceptible Acinetobacter baumannii (n = 12; MIC 0.06-0.25 mg/L), but the activity was reduced against nalidixic acid- and pefloxacin-resistant strains (n = 80; MIC 1-32 mg/L). Haemophilus influenzae (n = 70), Haemophilus parainfluenzae (n = 47) and Moraxella catarrhalis (n = 64) were inhibited by low concentrations of levofloxacin (MICs 0.016-0.03 mg/L, 0.03-0.12 mg/L) and 0.03-0.12 mg/L, respectively). Clostridium perfringens (n = 23; MIC 0.25-1 mg/L) was more susceptible than Bacteroides fragilis (n = 60; MIC 0.5-4 mg/L). Levofloxacin showed superior activity compared with ofloxacin against methicillin-susceptible staphylococci (n = 107; MIC 0.03-0.5 mg/L); the resistant strains (MICs 2-32 mg/L) were usually also resistant to methicillin. Levofloxacin was less effective against enterococci (n = 105; MIC 1-32 mg/L), but streptococci (n = 192) and pneumococci (n = 129), including 58 penicillin-non-susceptible strains, were inhibited by low concentrations (MICs 0.5-2 mg/L). According to the regression curve, zone diameters were usually 20-22 mm, 17-19 mm and 15-16 mm for MICs of 1, 2 and 4 mg/L, respectively. In conclusion, this study, performed on a large number of strains, confirms the superior anti-bacterial activity of levofloxacin compared with ofloxacin, especially against pathogens isolated from respiratory tract infections.