Influence of cefazolin prophylaxis and hospitalization on the prevalence of antibiotic-resistant bacteria in the faecal flora

Debridement, antibiotics, and implant retention after revision arthroplasty : antibiotic mismatch, timing, and repeated DAIR associated with poor outcome

AIMS

Debridement, antibiotics, and implant retention (DAIR) is a widely accepted form of surgical treatment for patients with an early periprosthetic joint infection (PJI) after primary arthroplasty. The outcome of DAIR after revision arthroplasty, however, has not been reported. The aim of this study was to report the success rate of DAIR after revision arthroplasty with a follow-up of two years.

METHODS

This retrospective study, conducted at the Sint Maartenskliniek, Nijmegen, the Netherlands, included 88 patients who underwent DAIR within 90 days of revision total hip or total knee arthroplasty between 2012 and 2019. Details of the surgical procedures and PJI were collected. Univariate analysis and a subgroup analysis of the culture-positive group were performed. Kaplan-Meier survivorship curves were constructed.

RESULTS

The overall success rate of DAIR, with respect to the retention of components and the cure of infection, was 68% after two years. DAIR performed with an interval of > 30 days after the index revision procedure (odds ratio (OR) 0.24 (95% confidence interval (CI) 0.08 to 0.72); p = 0.008), a repeated DAIR within 90 days (OR 0.37 (95% CI 0.14 to 0.97); p = 0.040), and the use of an immunosuppressive agent (OR 0.13 (95% CI 0.02 to 0.67); p = 0.012) were associated with a significantly reduced success rate. In the culture-positive group, a mismatch between the antibiotic treatment and the susceptibility of the organism was associated with a significantly lower success rate (OR 0.13 (95% CI 0.03 to 0.62); p = 0.007).

CONCLUSION

DAIR is an acceptable form of surgical treatment for patients with a suspected early PJI after revision arthroplasty of the hip or knee. DAIRs performed after a prolonged interval, multiple DAIRs, and antibiotic mismatches were significantly associated with an increased risk of failure. Optimization of the host immune response and the prevention of antibiotic mismatch are modifiable factors that may improve the outcome. The high rate of mismatches was an important finding, underlining the need for a review of the local microbiological data, which might improve the outcome. Cite this article: Bone Joint J 2022;104-B(4):464-471.

Susceptibility to antibiotics in isolates of Lactobacillus plantarum RAPD-type Lp299v, harvested from antibiotic treated, critically ill patients after administration of probiotics

Recultured Lactobacillus plantarum 299v-like strains were tested regarding antibiotic susceptibility, and no decrease was detected. Antibiotics are frequently used to treat patients in intensive care units (ICUs) and are associated with a significant risk of selection of resistant bacterial strains. In particular, it is possible that genetic transfer of antibiotic resistance to the resident gastrointestinal flora, as well as to administered probiotics, may be increased in the ICU setting. The aim of the present investigation was to detect possible changes in antimicrobial susceptibility in reisolates of the probiotic strain Lactobacillus plantarum 299v (Lp299v) given to antibiotic treated, critically ill patients. Lp299v-like strains were identified in cultures of biopsies and fecal samples from 32 patients given the probiotic strain enterally in two previous ICU studies. The patients received a variety of antibiotics. Isolates with the same genomic RAPD profile (RAPD-type) as Lp299v were obtained to enable monitoring of antibiotic susceptibility by E-tests. Forty-two isolates, collected throughout the course of illness, were tested against 22 different antibiotics. No obvious decrease in susceptibility was found for 21 of the tested antibiotics. There was a tendency toward decreased susceptibility to ampicillin. The stable antibiotic susceptibility profiles of the Lp299v-like isolates studied here suggests this probiotic is less likely to acquire resistance when administered to critically ill patients treated with broad-spectrum antibiotics.

Effects of a computerized provider order entry and a clinical decision support system to improve cefazolin use in surgical prophylaxis: a cost saving analysis

BACKGROUND

Computerized Provider Order Entry (CPOE) and Clinical Decision Support System (CDSS) help practitioners to choose evidence-based decisions, regarding patients' needs. Despite its use in developed countries, in Brazil, the impact of a CPOE/CDSS to improve cefazolin use in surgical prophylaxis was not assessed yet.

OBJECTIVE

We aimed to evaluate the impact of a CDSS to improve the use of prophylactic cefazolin and to assess the cost savings associated to inappropriate prescribing.

METHODS

This is a cross-sectional study that compared two different scenarios: one prior CPOE/CDSS versus after software implementation. We conducted twelve years of data analysis (3 years prior and 9 years after CDSS implementation), where main outcomes from this study included: cefazolin Defined Daily Doses/100 bed-days (DDD), crude costs and product of costs-DDD (cost-DDD/100 bed-days). We applied a Spearman rho non-parametric test to assess the reduction of cefazolin consumption through the years.

RESULTS

In twelve years, 84,383 vials of cefazolin were dispensed and represented 38.89 DDD/100 bed-days or USD 44,722.99. Surgical wards were the largest drug prescribers and comprised >95% of our studied sample. While in 2002, there were 6.31 DDD/100 bed-days, 9 years later there was a reduction to 2.15 (p<0.05). In a scenario without CDSS, the hospital would have consumed 75.72 DDD/100 bed-days, which is equivalent to USD 116 998.07. It is estimated that CDSS provided USD 50,433.39 of cost savings.

CONCLUSION

The implementation of a CPOE/CDSS helped to improve prophylactic cefazolin use by reducing its consumption and estimated direct costs.

Antibacterial gauzes are effective in preventing infections after percutaneous endoscopic gastrostomy placement: a retrospective analysis

OBJECTIVES

The most common complication after percutaneous endoscopic gastrostomy (PEG) placement is peristomal wound infection (up to 40% without antibiotic prophylaxis). Single-dose parenteral prophylactic antibiotics as advised by current guidelines decrease the infection rate to 9-15%. We assume a prolonged effect of local antibiotic treatment with antibacterial gauzes. This study is the first to describe the effect of antibacterial gauzes in preventing infections in PEG without the use of antibiotics.

METHODS

A retrospective data analysis was carried out of all patients with PEG insertion between January 2009 and October 2014 in the Catharina Hospital Eindhoven. Data include placement and the period of the first 2 weeks after PEG placement, and long-term follow-up. All patients received a locally applied antibacterial gauze polyhexamethylene biguanide immediately following PEG insertion for 3 days. No other antibiotics were administered. The main outcomes were wound infection, peritonitis, and necrotizing fasciitis; secondary outcomes included other complications.

RESULTS

A total of 331 patients with only antibacterial gauzes were analyzed. The total number of infections 2 weeks after PEG insertion was 9.4%, including 8.2% minor and 1.2% major infections (peritonitis). No wound infection-related mortality or bacterial resistance was found. Costs are five times lower than antibiotics, and gauzes are more practical and patient friendly for use.

CONCLUSION

Retrospectively, antibacterial gauzes are at least comparable with literature data on parenteral antibiotics in preventing peristomal wound infection after PEG placement, with an infection rate of 9.4%. Rates of other complications found in this study were comparable with current literature data.

The human microbiome as a reservoir of antimicrobial resistance

The gut microbiota is amongst the most densely populated microbial ecosystem on earth. While the microbiome exerts numerous health beneficial functions, the high density of micro-organisms within this ecosystem also facilitates horizontal transfer of antimicrobial resistance (AMR) genes to potential pathogenic bacteria. Over the past decades antibiotic susceptibility testing of specific indicator bacteria from the microbiome, such as Escherichia coli, has been the method of choice in most studies. These studies have greatly enlarged our understanding on the prevalence and distribution of AMR and associated risk factors. Recent studies using (functional) metagenomics, however, highlighted the unappreciated diversity of AMR genes in the human microbiome and identified genes that had not been described previously. Next to metagenomics, more targeted approaches such as polymerase chain reaction for detection and quantification of AMR genes within a population are promising, in particular for large-scale epidemiological screening. Here we present an overview of the indigenous microbiota as a reservoir of AMR genes, the current knowledge on this “resistome” and the recent and upcoming advances in the molecular diagnostic approaches to unravel this reservoir.

Duration of antibiotic prophylaxis for cardiac surgery: prospective observational study

OBJECTIVES

To assess the effect of prolonging antibiotic prophylaxis in cardiac surgery.

METHODS

Prospective before-after cohort study. In 2004, cefazolin was given pre- and intraoperatively at 1g doses while in 2007 it was continued after surgery for 24h. All consecutive adult patients undergoing coronary artery bypass graft, valve, and/or aortic operations during the study periods were included. The primary outcomes were deep sternal wound infection (DSWI) and mortality. Univariate and multivariate analyses were conducted to assess risk factors for DSWI.

RESULTS

954 patients between 1/2004 and 12/2004 were compared to 424 patients between 1/2007 and 6/2007. In 2007, there were significantly more patients >60yrs., emergency and combined operations and the mean logistic EuroSCORE was higher compared to 2004 (8.53% vs. 6.92%, p=0.006). The rate of DSWI decreased non-significantly from 3.8% (36/954) in 2004 to 2.6% (11/424) in 2007, p=0.27. The adjusted odds ratio of the study period for DSWI was 0.89 (95% confidence interval 0.70-1.13). There was no difference in 30-day (5.2% vs. 5.4%) or 6-month mortality (9.2% in both periods), despite increasing patients' risk.

CONCLUSIONS

Increasing the duration of antibiotic prophylaxis did not result in a significant decrease in DSWI. The value of prolonging antibiotic prophylaxis after cardiac operations should be further evaluated.

Clustering of antibiotic resistance of E. coli in couples: suggestion for a major role of conjugal transmission

Background

Spread of antibiotic resistance in hospitals is a well-known problem, but studies investigating the importance of factors potentially related to the spread of resistant bacteria in outpatients are sparse.

Methods

Stool samples were obtained from 206 healthy couples in a community setting in Southern Germany in 2002–2003. E. coli was cultured and minimal inhibition concentrations were tested. Prevalences of E. coli resistance to commonly prescribed antibiotics according to potential risk factors were ascertained.

Results

Prevalences of ampicillin resistance were 15.7% and 19.4% for women and men, respectively. About ten percent and 15% of all isolates were resistant to cotrimoxazole and doxycycline, respectively. A partner carrying resistance was the main risk factor for being colonized with resistant E. coli. Odds ratios (95% CI) for ampicillin and cotrimoxazole resistance given carriage of resistant isolates by the partner were 6.9 (3.1–15.5) and 3.3 (1.5–18.0), respectively.

Conclusion

Our data suggest that conjugal transmission may be more important for the spread of antibiotic resistance in the community setting than commonly suspected risk factors such as previous antibiotic intake or hospital contacts.