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Group A-streptococcal (GAS) infection can lead to various clinical presentations and is fulminant when it reaches the deep tissues, leading to a high morbidity and mortality. The severity of postpartum GAS infections is widely known. In this case report we describe the course of disease in a pregnant patient with GAS toxic shock syndrome with initial complaints of abdominal pain, diarrhea and fetal demise at first presentation. Within 10 hours this patient died. It is important to stay vigilant for a fulminant GAS infection in pregnant patients, to recognize it quickly and treat it adequately.

Background: Fracture-related infection is a serious complication after trauma. CERAMENT® G combines dead-space management with local release of gentamicin in a single-stage procedure. Bacterial resistance against antibiotics is increasing. The local effect of CERAMENT® G on bacteria resistant to systemically administered gentamicin is unknown., Questions/purposes: (1) What is the in vitro elution pattern of gentamicin from CERAMENT® G using a full washout model? (2) What is the in vitro antimicrobial activity (zone of inhibition) of CERAMENT® G against bacterial isolates found in fracture-related infection with different susceptibility levels toward gentamicin?, Methods: Elution of gentamicin from CERAMENT® G was determined in vitro over a period of 2 months. Elution experiments were performed in fivefold, with gentamicin being sampled in threefold at 19 different timepoints within 2 months. Antimicrobial activity was determined using the four most-frequently cultured bacterial species found in fracture-related infection: Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Enterobacter cloacae . For each of the species, four different isolates with a different susceptibility to gentamicin were used. According to the European Committee on Antimicrobial Susceptibility Testing, the susceptibility of each isolate was classified into four different groups: fully susceptible (minimum inhibitory concentration 0.064 to 4 mg/L), minimally resistant (minimum inhibitory concentration 4 to 16 mg/L), moderately resistant (minimum inhibitory concentration 8 to 96 mg/L), and highly resistant (minimum inhibitory concentration 24 to 1024 mg/L), depending on each organism. The antimicrobial activity of CERAMENT® G was determined according to the European Committee on Antimicrobial Susceptibility Testing disk protocol. The experiment was performed in fivefold for each isolate. The zone of inhibition was compared between each bacterial isolate and within each of the four separate species. Nonlinear regression statistics were calculated between the zone of interest and logarithmic minimum inhibitory concentration for each bacterial species., Results: After 24 hours, 95% of all available gentamicin was eluted, and gentamicin was still detectable after 2 months. CERAMENT® G showed antimicrobial activity against all bacterial species; only S taphylococcus aureus (with a minimum inhibitory concentration > 1024 mg/L) was not susceptible. The zone of interest of the different bacterial isolates was correlated with the logarithmic minimum inhibitory concentration., Conclusion: CERAMENT® G offers a bone substitute capable of releasing high levels of gentamicin within a short period of time. This study shows that CERAMENT® G has antimicrobial activity against bacterial isolates that are resistant to gentamicin when systemically administered. This finding raises the question of whether European Committee on Antimicrobial Susceptibility Testing cutoff points for systemic application are useful for the use of local CERAMENT® G. Standardized experiments to determine local antibiotic antimicrobial activity in fracture-related infection treatment are needed to form guidelines for the use of local antibiotics and ultimately improve fracture-related infection treatment., Clinical Relevance: Local concentrations of gentamicin with CERAMENT® G are much higher than when systemically administered. It seems effective against certain bacterial strains that are not affected by systemically reachable concentrations of gentamicin. CERAMENT® G might still be effective when bacteria that are resistant to systemically administered concentrations of gentamicin are occulated from patients with fracture-related infection., Competing Interests: Each author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Association of Bone and Joint Surgeons.)

Periprosthetic joint infection (PJI) is a serious complication after joint arthroplasty. PJI screening and conventional cultures may be inconclusive. Sonication fluid culturing stands out as a valuable adjunct technique for PJI diagnosis. This study aims to determine the clinical relevance of routine sonication for all (a)septic revisions. All patients who underwent (partial) hip or knee revision arthroplasty between 2012 and 2021 were retrospectively reviewed. We formed three groups based on the European Bone and Joint Society PJI criteria: infection confirmed, likely, and unlikely. We analyzed clinical, laboratory, and radiological screening. Sensitivity and specificity were calculated for synovial fluid (preoperative), tissue, and sonication fluid cultures. We determined the clinical relevance of sonication as the percentage of patients for whom sonication confirmed PJI; 429 patients who underwent (partial) revision of hip or knee arthroplasty were included. Sensitivity and specificity were 69% and 99% for synovial fluid cultures, 76% and 92% for tissue cultures, and 80% and 89% for sonication fluid cultures, respectively. Sonication fluid cultures improved tissue culture sensitivity and specificity to 83% and 99%, respectively. In 11% of PJIs, sonication fluid cultures were decisive for diagnosis. This is applicable to acute and chronic infections. Sonication fluid cultures enhanced the sensitivity and specificity of PJI diagnostics. In 11% of PJI cases, causative pathogens were confirmed by sonication fluid culture results. Sonication fluid culture should be performed in all revision arthroplasties.

Scope: Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen considered one of the paradigms of antimicrobial resistance, is among the main causes of hospital-acquired and chronic infections associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of P. aeruginosa to develop antimicrobial resistance through chromosomal mutations, the increasing prevalence of transferable resistance determinants (such as the carbapenemases and the extended-spectrum β-lactamases), and the global expansion of epidemic lineages. The general objective of this initiative is to provide a comprehensive update of P. aeruginosa resistance mechanisms, especially for the extensively drug-resistant (XDR)/difficult-to-treat resistance (DTR) international high-risk epidemic lineages, and how the recently approved β-lactams and β-lactam/β-lactamase inhibitor combinations may affect resistance mechanisms and the definition of susceptibility profiles., Methods: To address this challenge, the European Study Group for Antimicrobial Resistance Surveillance (ESGARS) from the European Society of Clinical Microbiology and Infectious Diseases launched the 'Improving Surveillance of Antibiotic-Resistant Pseudomonas aeruginosa in Europe (ISARPAE)' initiative in 2022, supported by the Joint programming initiative on antimicrobial resistance network call and included a panel of over 40 researchers from 18 European Countries. Thus, a ESGARS-ISARPAE position paper was designed and the final version agreed after four rounds of revision and discussion by all panel members., Questions Addressed in the Position Paper: To provide an update on (a) the emerging resistance mechanisms to classical and novel anti-pseudomonal agents, with a particular focus on β-lactams, (b) the susceptibility profiles associated with the most relevant β-lactam resistance mechanisms, (c) the impact of the novel agents and resistance mechanisms on the definitions of resistance profiles, and (d) the globally expanding XDR/DTR high-risk lineages and their association with transferable resistance mechanisms., Implication: The evidence presented herein can be used for coordinated epidemiological surveillance and decision making at the European and global level., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Because of the current lack of evidence-based antimicrobial treatment guidelines, Left Ventricular Assist Device (LVAD) infections are often treated according to local insights. Here, we propose a flowchart for protocolized treatment, in order to improve outcome., Methods: The flowchart was composed based on literature, consensus and expert opinion statements. It includes choice, dosage and duration of antibiotics, and indications for suppressive therapy, with particular focus on Staphylococcus aureus (SA) (Figure 1). The preliminary treatment results of 28 patients (2 from start cephalexin suppressive therapy) after implementation in July 2018 are described., Results: Cumulative incidence for first episode of infection in a 3-year time period was 27% (26 of 96 patients with an LVAD). Twenty-one of 23 (91%) first episodes of driveline infection (10 superficial and 13 deep; nine of 13 caused by SA) were successfully treated with antibiotics according to flowchart with complete resolution of clinical signs and symptoms. For two patients with deep driveline infections, surgery was needed in addition. There were no relapses of deep driveline infections, and only 2 SA deep driveline re-infections after 6 months. Nine patients received cephalexin of whom four patients (44%) developed a breakthrough infection with cephalexin-resistant gram-negative bacteria., Conclusions: The first results of this protocolized treatment approach of LVAD infections are promising. Yet, initiation of cephalexin suppressive therapy should be carefully considered given the occurrence of infections with resistant micro-organisms. The long-term outcome of this approach needs to be established in a larger number of patients, preferably in a multi-center setting., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Verkaik, Yalcin, Bax, Constantinescu, Brugts, Manintveld, Birim, Croughs, Bogers and Caliskan.)

The reference standard for fosfomycin antimicrobial susceptibility testing (AST) is agar dilution, but it is laborious and is not routinely used in diagnostic microbiology. In this study, we evaluated the performance of a ready-to-use commercially available agar dilution kit for fosfomycin AST (Liofilchem Diagnostics). We compared this kit with the reference standard agar dilution, performed according to the Clinical & Laboratory Standards Institute (CLSI) in 229 clinical isolates. The isolates were selected to represent both Gram-positive and Gram-negative microorganisms, with various MIC values. It consisted of 43 enterococci (E. faecalis n  = 16, E. faecium n  = 27), 13 methicillin-resistant S. aureus (MRSA), 118 Enterobacterales (Escherichia coli n  = 94, Klebsiella pneumoniae n  = 20, and Enterobacter cloacae complex n  = 4), 55 Pseudomonas aeruginosa, and three ATCC isolates. Using CLSI breakpoints for enterococci for oral treatment of urinary tract infections, European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints for intravenous dosing for Enterobacterales and Staphylococci, and epidemiological cutoff value for P. aeruginosa, the essential agreement was 87.5%, and 99.6% after discrepancy resolution. There was no very major error, and 1.9% major error before, and 0.9% major error after resolution of discrepancies. The commercial test showed 100% reproducibility. In conclusion, in comparison to the reference standard, the ready-to-use commercially available agar dilution kit for fosfomycin AST showed excellent performance. IMPORTANCE Fosfomycin is increasingly needed to treat infection due to multidrug resistant microorganisms. Yet, the antimicrobial susceptibility test (AST) of fosfomycin is fraught with difficulties or often laborious to perform. An easy-to-use AST method for fosfomycin is thus needed. In this study, we showed that the ready-to-use commercially available agar dilution kit, in comparison to the reference standard, showed excellent performance.

Biofilm-associated infections with Staphylococcus aureus are difficult to treat even after administration of antibiotics that according to the standard susceptibility assays are effective. Currently, the assays used in the clinical laboratories to determine the sensitivity of S. aureus towards antibiotics are not representing the behaviour of biofilm-associated S. aureus, since these assays are performed on planktonic bacteria. In research settings, microcalorimetry has been used for antibiotic susceptibility studies. Therefore, in this study we investigated if we can use isothermal microcalorimetry to monitor the response of biofilm towards antibiotic treatment in real-time. We developed a reproducible method to generate biofilm in an isothermal microcalorimeter setup. Using this system, the sensitivity of 5 methicillin-sensitive S. aureus (MSSA) and 5 methicillin-resistant S. aureus (MRSA) strains from different genetic lineages were determined towards: flucloxacillin, cefuroxime, cefotaxime, gentamicin, rifampicin, vancomycin, levofloxacin, clindamycin, erythromycin, linezolid, fusidic acid, co-trimoxazole, and doxycycline. In contrast to conventional assays, our calorimetry-based biofilm susceptibility assay showed that S. aureus biofilms, regardless MSSA or MRSA, can survive the exposure to the maximum serum concentration of all tested antibiotics. The only treatment with a single antibiotic showing a significant reduction in biofilm survival was rifampicin, yet in 20% of the strains, emerging antibiotic resistance was observed. Furthermore, the combination of rifampicin with flucloxacillin, vancomycin or levofloxacin was able to prevent S. aureus biofilm from becoming resistant to rifampicin. Isothermal microcalorimetry allows real-time monitoring of the sensitivity of S. aureus biofilms towards antibiotics in a fast and reliable way., Competing Interests: The authors have declared that no competing interests exist.

Debridement, antibiotics, and implant retention (DAIR) is a procedure to treat a periprosthetic joint infection (PJI) after total hip arthroplasty (THA) or total knee arthroplasty (TKA). The timing between the primary procedure and the DAIR is likely a determinant for its successful outcome. However, the optimal timing of a DAIR and the chance of success still remain unclear. We aimed to assess the risk of re-revision within 1 year after a DAIR procedure and to evaluate the timing of the DAIR in primary THA and TKA. We used data from the Dutch Arthroplasty Register (LROI) and selected all primary THA and TKA in the period 2007-2016 which underwent a DAIR within 12 weeks after primary procedure. A DAIR was defined as a revision for infection in which only modular parts were exchanged. A DAIR was defined as successful if not followed by a re-revision within 1 year after DAIR; 207 DAIRs were performed < 4  weeks after THA, of which 16 (8 %) received a complete revision within 1 year. DAIR procedures performed between 4 and 12 weeks ( n = 98 ) had a failure rate of 9 % ( n = 9 ). After TKA 126 DAIRs were performed in less than 4  weeks, of which 11 (9 %) received a complete revision within 1 year; 83 DAIRs were performed between 4 and 12 weeks, of which 14 (17 %) were revised. There was no significant difference in 1-year re-revision rate after a DAIR procedure by timing of the DAIR procedure for total hip and knee arthroplasty based on Dutch registry data., Competing Interests: The contact author declares that there are no competing interests., (Copyright: © 2021 Barry van der Ende et al.)

An increased prevalence of various filamentous fungi in sputum samples of patients with cystic fibrosis (CF) has been reported. The clinical significance, however, is mostly unclear. The aim of this study was to investigate the clinical relevance of Scedosporium spp. and Exophiala dermatitidis from sputum samples of patients with CF in the Netherlands. In this cross-sectional study, all CF patients of the Dutch national CF registry who were treated at five of the seven recognized CF centers during a 3-year period were included. We linked clinical data of the national CF registry with the national Dutch filamentous fungal database. We investigated the association between clinical characteristics and a positive sputum sample for Scedosporium spp. and E. dermatitidis, using logistic regression. Positive cultures for fungi were obtained from 3787 sputum samples from 699 of the 1312 patients with CF. Scedosporium spp. was associated with severe genotype, CF-related diabetes, several microorganisms, and inhaled antibiotics. E. dermatitidis was associated with older age, female sex, and Aspergillus spp. CF patients with and without Scedosporium spp. or E. dermatitidis seemed comparable in body mass index and lung function. This study suggests that Scedosporium spp. and E. dermatitidis are probably no major pathogens in CF patients in the Netherlands. Greater understanding of epidemiologic trends, risk factors, and pathogenicity of filamentous fungi in the respiratory tracts of patients with CF is needed., (© The Author(s) 2020. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)

Objectives: We used a dynamic bladder infection in vitro model with synthetic human urine (SHU) to examine fosfomycin exposures to effectively kill, or prevent emergence of resistance, among Pseudomonas aeruginosa isolates., Methods: Dynamic urinary fosfomycin concentrations after 3 g oral fosfomycin were simulated, comparing single and multiple (daily for 7 days) doses. Pharmacodynamic response of 16 P. aeruginosa (MIC range 1 to >1024 mg/L) were examined. Baseline disc diffusion susceptibility, broth microdilution MIC and detection of heteroresistance were assessed. Pathogen kill and emergence of resistance over 72 h following a single dose, and over 216 h following daily dosing for 7 days, were investigated. The fAUC0-24/MIC associated with stasis and 1, 2 and 3 log10 kill were determined., Results: Pre-exposure high-level resistant (HLR) subpopulations were detected in 11/16 isolates after drug-free incubation in the bladder infection model. Five of 16 isolates had >2 log10 kill after single dose, reducing to 2/16 after seven doses. Post-exposure HLR amplification occurred in 8/16 isolates following a single dose and in 11/16 isolates after seven doses. Baseline MIC ≥8 mg/L with an HLR subpopulation predicted post-exposure emergence of resistance following the multiple doses. A PK/PD target of fAUC0-24/MIC >5000 was associated with 3 log10 kill at 72 h and 7 day-stasis., Conclusions: Simulated treatment of P. aeruginosa urinary tract infections with oral fosfomycin was ineffective, despite exposure to high urinary concentrations and repeated daily doses for 7 days. Emergence of resistance was observed in the majority of isolates and worsened following prolonged therapy. Detection of a baseline resistant subpopulation predicted treatment failure., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The use of the Sensititre YeastOne YO10 alamarBlue assay for the in vitro susceptibility testing of Madurella mycetomatis was evaluated in M. mycetomatis isolates with and without pyomelanin secretion. Pyomelanin secretion did not influence visual endpoint reading; however, it caused a shift in peak absorbance from 570 nm to 620 nm when read spectrophotometrically. Therefore, when choosing the method for endpoint reading, the presence of pyomelanin should be considered., (Copyright © 2019 American Society for Microbiology.)

Introduction: Since 2009, the IlluminOss ® System is being used as an intramedullary fracture treatment. The system is characterized by the use of blue light to polymerize liquid monomer after its infusion in a polyethylene terephthalate balloon. Very few infections of the material have been observed, which might be explained by the possible antimicrobial side-effect of the blue light used in this intramedullary fracture stabilization system. This study aimed to assess this antimicrobial (side-)effect on S. aureus . Methods: A suspension of 1.5 x 10 3 CFU/ml of 8325-4 S. aureus was placed into five, custom made, black delrin cylinders. The implant was placed into the cylinders and the light source was activated for 200, 400, 600, 800, or 1,000 seconds. 100 µL of the light exposed suspension was grafted on blood agar and placed in a 35 degrees Celsius incubator for 24 hours. Colonies on each agar plate were counted and compared to the control plates (no blue light exposure). Results: The control plates showed a mean of 85 ± 15 colonies per plate. A statistically significant decrease was observed after 600 seconds of exposure time; mean colony count of 63 ± 4 (p <0.05). The absolute reduction was 24 ± 14 after 600 seconds exposure time. At 800 and 1,000 seconds, no statistically significant reduction was found compared with the control plates (means 72 ± 10 and 83 ± 14 colonies, respectively). Conclusions: In this study only a temporary reduction of S. aureus was observed. If future research regarding the antimicrobial characteristics of blue light used in the IlluminOss ® System is desired, it should focus on the need for oxygen and its availability and the dose and manner of applying the light., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Pseudomonas aeruginosa is one of the most important causes of infection in intensive care units (ICUs). It is intrinsically resistant to many antimicrobials and easily acquires additional resistance genes via horizontal gene transfer of mobile genetic elements. In this study, 1528 P. aeruginosa isolates obtained from a Dutch national surveillance programme between the years 1998-2011 were analysed for the presence of extended-spectrum β-lactamase (ESBL) genes (bla CTX-M , bla SHV , bla TEM , bla BEL , bla PER , bla VEB and bla OXA-10 ) and metallo-β-lactamase (MBL) genes (bla IMP , bla VIM and bla NDM ). Of the ceftazidime-resistant isolates, 6.2% tested phenotypically positive for ESBL. Moreover, a Verona integron-encoded MBL (VIM) gene was found in 3.1% of isolates that were phenotypically resistant to imipenem and/or meropenem. Multilocus sequence typing (MLST) of ESBL-positive isolates indicated ST1216, ST111 and ST622, with all bla VIM -positive isolates belonging to the ST111 clone. Although the prevalence of ESBL and MBL phenotypes in this Dutch national surveillance collection of >1500 ICU P. aeruginosa isolates was very low, all VIM-producing isolates belonged to the high risk-associated, international, clonal complex CC111, and most ESBL-producing isolates belonged to clonal complexes known for their successful spread, e.g. CC111 and CC235. These data indicate that high-risk clones of P. aeruginosa were present in the Netherlands between 1998-2011 and probably spread unnoticed throughout Dutch hospitals., (Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

Shiga toxin-producing Escherichia coli (STEC) is one of the major causes of human gastrointestinal disease and has been implicated in sporadic cases and outbreaks of diarrhoea, haemorrhagic colitis and haemolytic uremic syndrome worldwide. In this study, we determined the molecular characteristics and phylogenetic relationship of STEC isolates, and their genetic diversity was compared to that of other E. coli populations. Whole genome sequencing was performed on 132 clinical STEC isolates obtained from the faeces of 129 Dutch patients with gastrointestinal complaints. STEC isolates of this study belonged to 44 different sequence types (STs), 42 serogenotypes and 14 stx subtype combinations. Antibiotic resistance genes were more frequently present in stx1-positive isolates compared to stx2 and stx1 + stx2-positive isolates. The iha, mchB, mchC, mchF, subA, ireA, senB, saa and sigA genes were significantly more frequently present in eae-negative than in eae-positive STEC isolates. Presence of virulence genes encoding type III secretion proteins and adhesins was associated with isolates obtained from patients with bloody diarrhoea. Core genome phylogenetic analysis showed that isolates clustered according to their ST or serogenotypes irrespective of stx subtypes. Isolates obtained from patients with bloody diarrhoea were from diverse phylogenetic backgrounds. Some STEC isolates shared common ancestors with non-STEC isolates. Whole genome sequencing is a powerful tool for clinical microbiology, allowing high-resolution molecular typing, population structure analysis and detailed molecular characterization of strains. STEC isolates of a substantial genetic diversity and of distinct phylogenetic groups were observed in this study., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The ability of Escherichia coli O157:H7 to induce cellular damage leading to disease in humans is related to numerous virulence factors, most notably the stx gene, encoding Shiga toxin (Stx) and carried by a bacteriophage. Loss of the Stx-encoding bacteriophage may occur during infection or culturing of the strain. Here, we collected stx-positive and stx-negative variants of E. coli O157:H7/NM (nonmotile) isolates from patients with gastrointestinal complaints. Isolates were characterized by whole-genome sequencing (WGS), and their virulence properties and phylogenetic relationship were determined. Because of the presence of the eae gene but lack of the bfpA gene, the stx-negative isolates were considered atypical enteropathogenic E. coli (aEPEC). However, they had phenotypic characteristics similar to those of the Shiga toxin-producing E. coli (STEC) isolates and belonged to the same sequence type, ST11. Furthermore, EPEC and STEC isolates shared similar virulence genes, the locus of enterocyte effacement region, and plasmids. Core genome phylogenetic analysis using a gene-by-gene typing approach showed that the sorbitol-fermenting (SF) stx-negative isolates clustered together with an SF STEC isolate and that one non-sorbitol-fermenting (NSF) stx-negative isolate clustered together with NSF STEC isolates. Therefore, these stx-negative isolates were thought either to have lost the Stx phage or to be a progenitor of STEC O157:H7/NM. As detection of STEC infections is often based solely on the identification of the presence of stx genes, these may be misdiagnosed in routine laboratories. Therefore, an improved diagnostic approach is required to manage identification, strategies for treatment, and prevention of transmission of these potentially pathogenic strains., (Copyright © 2015, Ferdous et al.)

The purpose of this study was the evaluation of trends in the antimicrobial resistance of Pseudomonas aeruginosa from intensive care unit (ICU) patients and urology patients in the Netherlands. From 1998 to 2010, 1,927 consecutive P. aeruginosa isolates from ICU (n = 1,393) and urology service patients (n = 534) of 14 university and referral hospitals all over the Netherlands were collected and their susceptibility to relevant antibiotics was determined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Over time, a significant upward trend in the resistance of P. aeruginosa strains collected from ICUs to piperacillin (1.2 % to 10.6 %, p = 0.0175), piperacillin-tazobactam (1.2 % to 12.1 %, p = 0.0008), ceftazidime (1.2 % to 7.8 %, p = 0.0064), cefepime (4.8 % to 6.4 %, p = 0.0166), imipenem (6 % to 19.1 %, p < 0.0001), meropenem (8.3 % to 17 %, p = 0.0022) and ciprofloxacin (13.1 % to 31.2 %, p = 0.0024) was observed, as was the prevalence of multi-resistance (1.2 % to 8.5 %, p = 0.0002). For P. aeruginosa isolates from the urology services, the resistance to imipenem increased (4.1 % to 7.8 %, p = 0.0006) and to ciprofloxacin it decreased (22.4 % to 18.8 %, p = 0.025). Like in other countries, in the Netherlands, an increase in multi-resistant Gram-negatives is observed, suggesting the presence and dissemination of several mechanisms of resistance. Our findings emphasise the importance of local surveillance for the setting up of local antibiotic guidelines and to support optimal empiric therapy. With the observed increase in multi-resistance, the direct testing of alternative antibiotics like polymyxins and fosfomycin is essential. Our data also illustrate the importance of adequate outbreak control measures.