Screening for multi-drug-resistant Gram-negative bacteria: what is effective and justifiable?

Effectiveness is a key criterion in assessing the justification of antibiotic resistance interventions. Depending on an intervention's effectiveness, burdens and costs will be more or less justified, which is especially important for large scale population-level interventions with high running costs and pronounced risks to individuals in terms of wellbeing, integrity and autonomy. In this paper, we assess the case of routine hospital screening for multi-drug-resistant Gram-negative bacteria (MDRGN) from this perspective. Utilizing a comparison to screening programs for Methicillin-Resistant Staphylococcus aureus (MRSA) we argue that current screening programmes for MDRGN in low endemic settings should be reconsidered, as its effectiveness is in doubt, while general downsides to screening programs remain. To accomplish justifiable antibiotic stewardship, MDRGN screening should not be viewed as a separate measure, but rather as part of a comprehensive approach. The program should be redesigned to focus on those at risk of developing symptomatic infections with MDRGN rather than merely detecting those colonised

Rhenium and yttrium ions as antimicrobial agents against multidrug resistant Klebsiella pneumoniae and Acinetobacter baumannii biofilms

© 2019 The Authors. Letters in Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology. Antimicrobial resistance presents major global concerns to patient health. In this study, metal ions of molybdenum, rhenium, yttrium and thallium were tested against bacteria in planktonic and biofilm form using one strain of Klebsiella pneumoniae and Acinetobacter baumannii. The antimicrobial efficacy of the metal ions was evaluated against the planktonic bacterial strains using minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations, whilst the efficacy of the metal ions against biofilms was tested using a crystal violet biofilm assay. Live Dead staining was used to visualize the antimicrobial activity elicited by the metal ions on the bacterial cell. The results showed that higher concentrations of the metals were required to inhibit the growth of biofilms (72·9 mg l −1 to 416·7 mg l −1 ), in comparison to their planktonic counterparts. MICs of the metal ions (<46·9 mg l −1 ) (planktonic cells) did not affect biofilm formation. Overall, rhenium and yttrium were effective antimicrobial agents. Molybdenum demonstrated the greatest level of biotoxicity. When taking into account these results and the known toxicity of thallium, it is possible that rhenium or yttrium ions could be developed as effective biocidal formulations in order to prevent transmission in healthcare environments. Significance and Impact of the Study: The metal ions, molybdenum, rhenium, thallium and yttrium were tested against both Klebsiella pneumoniae and Acinetobacter baumannii in planktonic and biofilm forms. This research demonstrated that all the metal ions may be effective antimicrobial agents. However, molybdenum induced high levels of cytotoxicity, whilst, there was no significant difference in the toxicity of the other metal ions tested. When considering the results for the antimicrobial efficacy and biotoxicity of the metal ions, in conjunction with the known toxicity of thallium in certain chemical compositions, it was concluded that overall rhenium or yttrium ions may be effective antimicrobial agents, one potential application may be utilizing these metal ions in hospital surface cleaning formulations

Invasive infection caused by <i>Klebsiella pneumoniae</i> is a disease affecting patients with high comorbidity and associated with high long-term mortality

<div><p><i>Klebsiella pneumoniae</i> (KP) is after <i>Escherichia coli</i> (EC) the most common gram-negative species causing invasive infections. Herein, we analyzed risk factors and prognosis in invasive infections caused by KP versus EC, in an area with low antimicrobial resistance. Moreover, we compared antimicrobial resistance and relative prevalence of KP and EC (KP/EC-ratio) in different European countries, using EARS-Net data. Adult patients admitted to Karolinska University Hospital 2006–2012 with invasive infection caused by KP (n = 599) were matched regarding sex and age with patients infected by EC. The medical records were retrospectively reviewed. Comorbidity was adjusted for with multivariable analysis. European data were retrieved from the EARS-Net database. No differences were observed in 7- and 30-day mortality between the groups. The 90-day mortality was significantly higher in the KP cohort (26% versus 17%, p<0.001), but not after adjusting for comorbidity. Malignancy was seen in 53% of the patients with KP versus 38% with EC, OR 1.86 (1.34–2.58). A significant increase in the rate of ESBL-production was observed in EC, but not in KP. The KP/EC-ratio remained stable. In contrast, European data showed increasing percentages of isolates non-susceptible to third-generation cephalosporins in EC and KP, and increasing KP/EC-ratio. Invasive infection caused by KP is a disease affecting patients with high comorbidity and associated with high 90-d mortality. The stable KP/EC-ratio and low occurrence of antimicrobial resistance in data from Karolinska University Hospital compared to aggregate data from 20 EARS-Net countries could be related to absence of clonal spread of multidrug-resistant KP.</p></div

Associated factors for mortality in the extended <i>K</i>. <i>pneumoniae</i> cohort, factors significant in multivariable analysis.

<p>Associated factors for mortality in the extended <i>K</i>. <i>pneumoniae</i> cohort, factors significant in multivariable analysis.</p

Rates of invasive isolates non-susceptible to third-generation cephalosporins among <i>K</i>. <i>pneumoniae</i> and <i>E</i>. <i>coli</i> 2006–2012, and <i>K</i>. <i>pneumoniae</i> / <i>E</i>. <i>coli</i> (KP/EC) ratio.

<p>A) Karolinska University Hospital. B) Twenty countries within EU/EEA reporting to EARS-Net. Population-weighted data.</p

Clinical characteristics of patients with invasive infection caused by <i>K</i>. <i>pneumoniae</i> versus <i>E</i>. <i>coli</i>, multivariable analysis.

<p>Clinical characteristics of patients with invasive infection caused by <i>K</i>. <i>pneumoniae</i> versus <i>E</i>. <i>coli</i>, multivariable analysis.</p

Invasive infection caused by <i>Klebsiella pneumoniae</i> is a disease affecting patients with high comorbidity and associated with high long-term mortality - Fig 3

<p><b>The percentages of <i>E</i>. <i>coli</i> (3A) and <i>K</i>. <i>pneumoniae</i> (3B) isolates non-susceptible against third-generation cephalosporins plotted against the ratios of <i>K</i>. <i>pneumoniae/E</i>. <i>coli</i> (KP/EC ratio) among 20 European countries 2006–2012.</b> Each dot (n = 140) represents one country a certain year.</p

Kaplan-Meier survival curve <i>K</i>. <i>pneumoniae</i> versus <i>E</i>. <i>coli</i> cohort during 90 days.

<p>Log-rank test p<0.001.</p

Detection of Klebsiella pneumoniae Carbapenemase (KPC) Production in Non-Klebsiella pneumoniae Enterobacteriaceae Isolates by Use of the Phoenix, Vitek 2, and Disk Diffusion Methods▿

In this study, we tested the abilities of the Vitek 2, BD Phoenix, and Kirby Bauer disk diffusion tests to detect carbapenemase production in a collection of 14 Klebsiella pneumoniae carbapenemase (KPC)-producing non-Klebsiella pneumoniae isolates. In addition, we evaluated 13 KPC-positive K. pneumoniae isolates by using each of these methods and applied both 2009 and 2010 CLSI carbapenem interpretive guidelines