Forty-eight clinical Acinetobacter isolates with different epidemic behavior were investigated for the presence of integrons and plasmids and for antibiotic susceptibility. Integrons were demonstrated in 50% of the strains by an integrase gene PCR. Epidemic strains of Acinetobacter baumannii were found to contain significantly more integrons than nonepidemic strains. Also, the presence of integrons was significantly correlated with simultaneous resistance to several antibiotics. Plasmids were detected in 42% of the strains. However, there was no significant correlation between the numbers of plasmids and integrons in Acinetobacter species strains, no significant difference in the number of plasmids between epidemic and nonepidemic A. baumannii strains, and no significant correlation between the presence of plasmids and antibiotic resistance. Hence, it is likely that integrons play an important role in antibiotic resistance and thereby in the epidemic behavior of A. baumannii. Because the integrase gene PCR identified almost three-quarters of the epidemic A. baumannii isolates (17 of 23), this seems to be a rapid and simple technique for the routine screening and identification of clinical A. baumannii isolates with epidemic potential.

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Objectives: To assess the diagnostic performance of rapid lateral flow immunochromatographic assays (LFAs) compared with an ELISA and nucleic acid amplification tests (NATs) in individuals with suspected coronavirus disease 2019 . Methods: Patients presenting to a Dutch teaching hospital were eligible between 17 March and 10 April 2020, when they had respiratory symptoms that were suspected for COVID-19. The performances of six different LFAs were evaluated in plasma samples obtained on corresponding respiratory sample dates of NATs testing. Subsequently, the best performing LFA was evaluated in 228 patients and in 50 sera of a historical patient control group. Results: In the pilot analysis, sensitivity characteristics of LFA were heterogeneous, ranging from 2/20 (10%; 95% CI 0%e23%) to 11/20 (55%; 95% CI 33%e77%). In the total cohort, Orient Gene Biotech COVID-19 IgG/IgM Rapid Test LFA had a sensitivity of 43/99 (43%; 95% CI 34%e53%) and specificity of 126/129 (98%; 95% CI 95%e100%). Sensitivity increased to 31/52 (60%; 95% CI 46%e73%) in patients with at least 7 days of symptoms, and to 21/33 (64%; 95% CI 47%e80%) in patients with C-reactive protein (CRP) 100 mg/L. Sensitivity and specificity of Wantai SARS-CoV-2 Ab ELISA was 59/95 (62%; 95% CI 52%e72%) and 125/128 (98%; 95% CI 95%e100%) in all patients, respectively, but sensitivity increased to 38/48 (79%; 95% CI 68% e91%) in patients with at least 7 days of symptoms. Conclusions: There is large variability in diagnostic test performance between rapid LFAs, but overall limited sensitivity and high specificity in acutely admitted patients. Sensitivity improved in patients with longer existing symptoms or high CRP. LFAs should only be considered as additional triage tools when these may lead to the improvement of hospital logistics.

In order to determine the prevalence of vancomycin-resistant enterococci (VRE) in The Netherlands, 624 hospitalized patients from intensive care units or hemato-oncology wards in nine hospitals and 200 patients living in the community were screened for VRE colonization. Enterococci were found in 49% of the hospitalized patients and in 80% of the patients living in the community. Of these strains, 43 and 32%, respectively, were Enterococcus faecium. VRE were isolated from 12 of 624 (2%) and 4 of 200 (2%) hospitalized patients and patients living in the community, respectively. PCR analysis of these 16 strains and 11 additional clinical VRE isolates from one of the participating hospitals revealed 24 vanA gene-containing, 1 vanB gene-containing, and 2 vanC1 gene-containing strains. All strains were cross-resistant to avoparcin but were sensitive to the novel glycopeptide antibiotic LY333328. Genotyping of the strains by arbitrarily primed PCR and pulsed-field gel electrophoresis revealed a high degree of genetic heterogeneity. This underscores a lack of hospital-driven endemicity of VRE clones. It is suggested that the VRE in hospitalized patients have originated from unknown sources in the community. Enterococcus spp. have recently emerged as important nosocomial pathogens (35). According to the data from the National Nosocomial Infections Surveillance System, enterococci are the fourth leading cause of nosocomial infections in the United States (12). Enterococcal infections that have frequently been reported include urinary tract infections, bacteremia, endocarditis, intra-abdominal infections, and surgical wound infections (27). Enterococcus faecalis is commonly isolated from the human gastrointestinal tract, whereas Enterococcus faecium is less frequently isolated from that site (31). This latter species, however, is noted for its antimicrobial resistance. Vancomycin-resistant E. faecium (VREF) strains have emerged in a setting of increasing high-level resistance of enterococci to penicillins and aminoglycosides (28). During the last few years, nosocomial outbreaks due to VREF have been described (17, 25). The emergence of VREF has raised serious concerns (28), and in response, the Hospital Infections Control Practices Advisory Committee (HICPAC), in collaboration with the Centers for Disease Control and Prevention, has developed recommendations for preventing the spread of vancomycin-resistant enterococci (VRE) (18). Given the concern that vancomycin resistance genes may transfer from enterococci to Staphylococcus aureus, a phenomenon that has been observed in vitro (31), control measures have already been proposed, should vancomycin-resistant S. aureus strains eventually arise (10). MATERIALS AND METHODS Prevalence study. Five Dutch university hospitals in Rotterdam, Utrecht, Nijmegen, and Amsterdam and four regional teaching hospitals in Breda and Tilburg participated in the study. Six hundred twenty-four patients who were hospitalized in the following wards were screened for gastrointestinal carriage of VRE...

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Thirty-one strains of Acinetobacter species, including type strains of the 18 genomic species and 13 clinical isolates, were compared by amplified ribosomal DNA restriction analysis (ARDRA), random amplified polymorphic DNA analysis (RAPD), and amplified fragment length polymorphism (AFLP) fingerprinting. ARDRA, performed with five different enzymes, showed low discriminatory power for differentiating Acinetobacter at the species and strain level. The standardized commercially available RAPD kit clearly enabled the discrimination of all Acinetobacter genomic species but showed great polymorphism between isolates ofAcinetobacter baumannii. AFLP fingerprinting with radioactively as well as fluorescently labelled primers showed high discriminatory power for the identification of 18Acinetobacter genomic species and typing of 13 clinical Acinetobacter isolates. Compared to radioactive AFLP, fluorescent AFLP was technically fast and simple to perform, and it permitted analysis with an automated DNA sequencer. Fluorescent AFLP seems particularly well suited for studying the epidemiology of nosocomial infections and outbreaks caused by Acinetobacterspecies.

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Objectives : First, to describe SARS-CoV-2 T cell and antibody responses in a prospective cohort of healthcare workers that suffered from mild to moderate COVID-19 approximately one year ago. Second, to assess COVID-19 vaccine-induced immune responses in these prior-infected individuals. Methods : SARS-CoV-2-specific T cell and anti-SARS-CoV-2-Spike-RBD immunoglobulin G (IgG) responses in blood were determined before COVID-19 vaccination with mRNA-1273, BNT162b2, Ad26.CoV2-S or ChAdOx1-S, two weeks after first vaccination, and after second vaccination. Results : 55 prior SARS-CoV-2 infected and seroconverted individuals were included. S1-specific T cell responses and anti-RBD IgG were detectable one year post SARS-CoV-2 infection: 24 spot-forming cells per 10 6 peripheral blood mononuclear cells (SFCs/10 6 PBMCs) after S1 stimulation and anti-RBD IgG concentration of 74 (IQR 36-158) IU/mL. Responses after the first and second vaccination were comparable with S1-specfic T cell responses of 198 (IQR 137-359) and 180 (IQR 103-347) SFCs/10 6 PBMCs, and IgG concentrations of 6792 (IQR 3386-15180) and 6326 (IQR 2336-13440) IU/mL, respectively. These responses retained up to four months after vaccination. Conclusions : Both T cell and IgG responses against SARS-CoV-2 persist for up to one year after COVID-19. A second COVID-19 vaccination in prior-infected individuals did not further increase immune responses in comparison to one vaccination.