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We evaluated neutralizing antibodies against the Omicron variant and Anti-Spike IgG response in solid organ (SOT) or hematopoietic stem cell (HSTC) recipients after a third dose of BNT162b2 (BNT) or CoronaVac (CV) following two doses of CV. In total, 95 participants underwent SOT (n = 62; 44 liver, 18 kidney) or HSCT (n = 27; 5 allogeneic, 22 autologous) were included from five centers in Turkey. The median time between third doses and serum sampling was 154 days (range between 15 to 381). The vaccine-induced antibody responses of both neutralizing antibodies and Anti-Spike IgGs were assessed by plaque neutralizing assay and immunoassay, respectively. Neutralizing antibody and Anti-Spike IgG levels were significantly higher in transplant patients receiving BNT compared to those receiving CV (Geometric mean (GMT):26.76 vs. 10.89; p = 0.03 and 2116 Au/mL vs. 172.1 Au/mL; p < 0.001). Solid organ transplantation recipients, particularly liver transplant recipients, showed lower antibody levels than HSCT recipients. Thus, among HSCT recipients, the GMT after BNT was 91.29 and it was 15.81 in the SOT group (p < 0.001). In SOT, antibody levels after BNT in kidney transplantation recipients were significantly higher than those in liver transplantation recipients (GMT: 48.32 vs. 11.72) (p < 0.001). Moreover, the neutralizing antibody levels after CV were very low (GMT: 10.81) in kidney transplantation recipients and below the detection limit (<10) in liver transplant recipients. This study highlights the superiority of BNT responses against Omicron as a third dose among transplant recipients after two doses of CV. The lack of neutralizing antibodies against Omicron after CV in liver transplant recipients should be taken into consideration, particularly in countries where inactivated vaccines are available in addition to mRNA vaccines. [ABSTRACT FROM AUTHOR]

Objective: Urinary tract infections (UTIs) are common in the community. The prevalence of UTIs rises in the elderly as a result of age-related changes and comorbidities. In treating the elderly, it is important to choose antibiotics carefully and avoid unnecessary ones. The goal of this study was to analyze the bacteria isolated from geriatric urine samples and their resistance patterns. Materials and Methods: Urine culture results in geriatric patients (>65 years old) were analyzed between January 1, 2016 and February 1, 2020. Antibiotic resistance was evaluated in frequently isolated bacteria. In terms of antibiotic resistance, antibiotics that can be used in outpatient therapy and do not require the approval of an infectious disease specialist were investigated. Results: The records of 37735 urinary samples were screened. In 31.3% (11840/37735) of the urine culture microorganisms were isolated. Escherichia coli was the most common microorganism with a rate of 40.1% (4758/11840), followed by Klebsiella spp. with 15.5% (1844/11840), Enterococcus spp. with 10.3% (1222/11840), and Pseudomonas aeruginosa with 3.4% (406/11840). Ceftriaxone resistance of 37.6% was found in Escherichia coli; ciprofloxacin resistance was 41.5%, trimethoprim-sulfamethoxazole (TMP-SMX) resistance was 43.4%, and nitrofurantoin resistance was 1%. There was no resistance to fosfomycin. The antibiotic resistance of Klebsiella spp. gave a result of 41.6% ceftriaxone resistance, while ciprofloxacin resistance was 32.6%, and TMP-SMX resistance was 39.6%. The antibiotic resistance of Pseudomonas aeruginosa was 19.04% ciprofloxacin resistance, and 5.1% amikacin resistance. In Enterococcus spp. ampicillin resistance was found to be 42.9%. Conclusion: Infections in geriatric patients can quickly prove fatal. Antibiotic selection is critical in regard to elderly patients, and knowing regional antimicrobial resistance patterns is important. But balancing efficacy, safety, and tolerability with the development of antimicrobial resistance in this patient population is difficult. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ankara University Faculty of Medicine / Ankara Üniversitesi Tip Fakültesi Mecmuasi is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/aim: The aim of this study is to evaluate the distribution, sources, clinical features, and mortality rates of bacteremia due to evaluation of extensively drug-resistant (XDR) gram negative among solid-organ transplant (SOT) recipients. Materials and methods: A retrospective study of SOT recipients with bacteremia due to XDR gram-negative pathogens in 11 centers between 2016 and 2018 was conducted. Patients’ records were evaluated. Results: Of 171 bacteremia that occurred in 164 SOT recipients, 93 (56.7%) were liver, 46 (28%) kidney, 14 (8.5%) heart, and 11 (6.7%) lung recipients. Bacteremia episodes were recorded in the first year in 63.7% of the patients (n = 109), early-onset bacteremia was recorded in 45% (n = 77) of the episodes. In multivariate analysis, catheter-associated bacteremia was an independent risk factor for 7-day mortality (p = 0.037), and early-onset bacteremia was found as an independent risk factor for 30-day mortality (p = 0.017). Conclusion: Difficult-to-treat infections due to XDR bacteria in SOT recipients shadow the success of transplantation. Central venous catheters seem to be the main risk factor. Judicious use of medical devices is of pivotal importance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ankara University Faculty of Medicine / Ankara Üniversitesi Tip Fakültesi Mecmuasi is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of the Turkish Society of Cardiology / Türk Kardiyoloji Derneği Arşivi is the property of KARE Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Candidaemia still continues to be a serious medical concern and the epidemiology of candidaemia varies according to geographical areas. We aim to determine the incidence, local epidemiology, Candida species distribution and crude mortality rates of candidaemia. We retrospectively evaluated candidaemia episodes in between January 2007 and August 2014. We compared demographic, clinical, microbiological findings and mortality rates of episodes caused by Candida albicans and non- albicans Candida species. Overall the candidaemia incidences were 1.23 episodes/1000 admissions. A significant negative slope among candidaemia episodes and years was determined. Overall C. albicans (54.6%) was the most common species followed by Candida glabrata, Candida tropicalis and Candida parapsilosis respectively. Preinfection hospital stay and length of hospital stay were statistically longer in patients with non- albicans Candida candidaemia than in patients with C. albicans candidaemia. The source of candidaemia was unknown in 52.5% of all episodes. Central venous catheters among non- albicans Candida candidaemia episodes and urinary system among C. albicans candidaemia episodes were common source of candidaemia compared to each other. Previous antifungal therapy preceding candidaemia and concomitant bacteraemia were significantly associated with non- albicans Candida candidaemia. Continuous local surveillance will preserve its pivotal importance in formulating empirical antifungal therapy and improving management of candidaemia. [ABSTRACT FROM AUTHOR]

Introduction: Carbapenem-Resistant Klebsiella pneumoniae (CRKP) is difficult to treat due to resistance to conventional antibiotics. A difficultto-treat critically ill septic patient with a ventriculoperitoneal shunt (VPS) infection associated with CRKP is presented. Case: A 19-year-old male with a history of decompression surgery and VPS due to spontaneus subarachnoid hemorrhage was admitted to ICU with unconsciousness, seizure and fever. His APACHE II score was 17, SOFA score 6, and GCS 4 at ICU admission. He was intubated and meropenemvancomycin combination therapy was initiated for preliminary diagnosis of sepsis due to VPS-related ventriculitis. Surveillance cultures indicated CRKP. On 5th day of ICU admission, ventriculer drainage tube (VDT) was placed after hydrosephalus was detected in the cranial computed tomography. On 10th day Polymixin E was added to antibiotherapy due to the development of CRKP bacteremia and ventilator-associated pneumonia. Septic shock developed again after cessation of antibiotherapy. Ceftazidime-avibactam treatment was started for CRKP detected in CSF cultures as well as blood and endotracheal aspirate. Meropenem and polymyxin E were restarted due to ceftazidime-avibactam resistance and intraventricular (ivt) polymyxin E was added. VPS was removed because of multiple septic shock attacks and continued CRKP growth in CSF and blood cultures. As a salvage treatment, meropenem, tigecycline (iv and ivt) polymyxin B was administered. After 14 days of no growth in control cultures and clinical response, VDT was removed and a new VPS was inserted. He was discharged to home from the hospital on the 185th day of ICU admission. Discussion: The blood-brain and blood-CSF barriers make it difficult for many anti-infective drugs to reach effective concentrations in the CNS after systemic administration. Treatment options for sepsis due to CNS infections with CRKP are quite limited. This is the first successful treatment of a VPS related septic shock patient with ivt tigecycline from Turkey. [ABSTRACT FROM AUTHOR]

Background and Aim: Tigecycline is a semi-synthetic tetracycline with activity against most multidrug-resistant (MDR) bacteria. Methods: We studied in vitro activity of tigecycline by agar dilution (AD) and Etest methods to evaluate their correlation. The study included 206 isolates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and MDR Acinetobacter baumannii recovered from blood cultures of patients of Baskent University between 2008 and 2010. Results: ESBL-producing E. coli had MIC50/MIC90 values of 0.5/0.5 µg/ml by AD and 0.25/0.5 µg/ml by Etest. ESBL-producing K. pneumoniae had MIC50/MIC90 values of 1/2 µg/ml by AD and 0.75/2 µg/ml by Etest, whereas MDR A. baumannii had MIC50/MIC90 values of 4/4 µg/ml by AD and 2/4 µg/ml by Etest. The correlation between AD and Etest was weak for ESBL-producing E. coli and strong for ESBL-producing K. pneumoniae and MDR A. baumannii. Tigecycline MIC values for ESBL-producing E. coli were lower than the tigecycline concentration, while they were higher than the concentrations attainable by treatment doses for A. baumannii. Conclusion: Tigecycline is an appropriate agent in the treatment of E. coli bacteremia, but it is not for treating A. baumannii bacteremia. Tigecycline could be used for K. pneumoniae bacteremia treatment after determining its MIC value. Determining the MIC value by gold-standard methods is more appropriate due to the correlation between Etest and AD at high MIC values. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Bloodstream infections (BSI) are frequently seen after solid organ transplantation. The incidence of bloodstream infections differs among the types of transplantation. The microbiological features and antimicrobial resistance patterns change from centre to centre. Aims: To evaluate the incidence and spectrum of aetiological agents of bloodstream infections among solid organ transplantation recipients. Study Design: Retrospective descriptive study. Methods: Medical records of solid organ transplant recipients in the period between January 1st 2004 and August 15th 2012 were assessed retrospectively. The study population comprised 927 (64 heart, 556 kidney, 307 liver) consecutive recipients. Bloodstream infections were divided into three groups according to the onset time of bloodstream infections after transplantation: early, mid-term and late. The incidence and microbiological features of bloodstream infections were evaluated. Results: The number of bloodstream infection episodes was 317 in 191 recipients which was distributed as 228 (72%) in liver, 70 (22%) in kidney and 19 (6%) in heart transplantation. Ninety-eight 98 (30.9%) of the episodes were diagnosed within the early period, 134 (42.3%) within the mid-term and 85 (26.8%) in the late period. Early and mid-term bloodstream infections were seen statistically more often in liver than in kidney or heart transplantation (p=0.01 and p=0.031, respectively). Late bloodstream infections were also common in liver transplant recipients which was not statistically significant (p=0.229). Conclusion: Liver transplant recipients are at the highest risk for developing BSI after transplantation in early, mid-term and late periods. [ABSTRACT FROM AUTHOR]

Introduction: Necrotizing fasciitis is a serious infection of the subcutaneous tissue and fascia. Despite being rare, it may have a high mortality rate because it usually leads to rapidly progressing fascial necrosis. The purpose of this study was to report a case of early stage necrotizing fasciitis that developed after cryotherapy for a penile condyloma, 19 days before the index emergency department admission. Case Report: A 32-year-old man without any history of systemic disorder was admitted to our emergency department for groin swelling and burning sensation that developed 12 hours before his hospital admission. Edema and hyperemia starting from the left inguinal region and extending to the penis and scrotum were noted on physical examination. While initially being considered a case of early stage necrotizing fasciitis and tested for it, the patient rapidly developed a bulla and entered intermediate stage. We hospitalized the patient with an initial diagnosis of necrotizing fasciitis and initiated dual antibiotic therapy. Furthermore, we debrided the wound and excised the necrotic tissue debris. We discharged the patient on the 12th day. Conclusion: Clinical suspicion should be high for necrotizing fasciitis in emergency. Initiating the most appropriate medical and surgical therapy as soon as the diagnosis is made is the key for preventing mortality and morbidity. [ABSTRACT FROM AUTHOR]

Aim: Community-acquired infections caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria are an emerging problem. Digestive tract colonization is a prerequisite for infections by ESBL-producing microorganisms. The aim of this study was to determine the prevalence of and risk factors for fecal carriage of ESBL-producing Escherichia coli ( E. coli) or Klebsiella spp. in the community. Materials and Methods: A total of 928 stool samples admitted to the laboratory during a four-month period were included in the study. Samples were diluted in saline and cultured in two EMB agar plates supplemented with either 1 μg/ml cefotaxime or 1 μg/ml ceftazidime. All isolates that grew were identified to the species level. E. coli and Klebsiella spp. strains were tested for ESBL production with ceftazidime and ceftazidimeclavulanate discs according to the Clinical and Laboratory Standards Institute (CLSI) Guideline. Results: Of the 928 stool samples included, 133 (14%) were isolated from inpatients and 795 (86%) from outpatients. Sixty-three (47.3%) of 133 hospitalized and 121 (15.2%) of 795 outpatients harbored ESBL-producing E. coliand Klebsiellaspp. (P = 0.000). Chronic hepatic failure (OR: 8.7, CI: 1.65–46.12; P = 0.011) and recent antibiotic use (OR: 4.4, CI: 1.76–11.16; P = 0.002) were found to be associated with ESBL positivity for the hospitalized patients. Recent antibiotic use (OR: 2.8, CI: 1.61-5.12; P = 0.000) was found to be the only independent variable associated with ESBL positivity for the outpatients. Conclusions: The high prevalence (15.2%) of fecal carriage of ESBL-producing bacteria in the community warrants further study in this field including the consequences of this colonization in the hospital setting. [ABSTRACT FROM AUTHOR]

ABSTRACT: Although group A ?-hemolytic streptococcus is an uncommon cause of infective endocarditis, an increase in the incidence of invasive group A strepto coccusinfections including bacteremia has been reported in the last two decades. Herein we report Streptococcus pyogenes endocarditis in a previously healthy adult patient who was hospitalized to investigate the etiology of fever. Because of a suspicion of a new vegetation appeared in the second (aortic) valve in the 14th day of high dose penicillin G treatment, the mitral and aortic valves were replaced by mechanical prosthesis on the 22nd day of treatment. He was discharged from hospital after the 6 week course of antibiotic treatment [ABSTRACT FROM AUTHOR]

The article discusses the detection of OXA-48-like carbapenemase-producing Klebsiella pneumoniae in a tertiary care center in Turkey. Five of the 16 strains were isolated from solid organ transplant recipients hospitalised at Baskent University Hospital between the years 2007 and 2011. Based on in vitro susceptibility test, all Klebsiella pneumonia isolates were susceptible to amikacin and colistin.

A letter to the editor is presented which is concerned with mirtazapine-induced thrombocytopenia and neutropenia.

Abstract: The aim of this study was to assess the in vitro activity of a number of non-traditional antibiotics (colistin, azithromycin, doxycycline and rifampicin) against multidrug-resistant (MDR) strains of Pseudomonas aeruginosa and Acinetobacter baumannii isolated from Intensive Care Units (ICUs). We also used the checkerboard method to determine whether combinations of colistin with another non-traditional antibiotic or meropenem act synergistically against these strains. Thirty-five P. aeruginosa and 25 A. baumannii strains that were found to be MDR were included the study. Isolates were collected from the specimens of patients in ICUs from 2001 to 2003. All isolates were identified by standard methods and stored at −20°C until use. Antibiotic powders of azithromycin, doxycycline, rifampicin, meropenem and colistin were obtained from their manufacturers. Minimum inhibitory concentrations (MICs) were determined by the agar dilution method on Mueller–Hinton agar. Five strains of A. baumannii and five strains of P. aeruginosa, all of which had different MIC values for colistin, were selected for the synergy study using the checkerboard titration method. The susceptibility results for doxycycline and meropenem were interpreted according to National Committee for Clinical Laboratory Standards guidelines. The susceptibility breakpoints for colistin and rifampicin were established as 4mg/L and 2mg/L, respectively, based on previous studies. Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 were used as control strains. Testing against the P. aeruginosa strains revealed high MIC50 values for all the drugs except colistin. Doxycycline and colistin were both effective against the A. baumannii strains, with high susceptibility rates of 92% and 100%, respectively. Azithromycin had a high MIC50 value against these strains, whilst rifampicin had a moderate effect (susceptibility rate 64%). The combination of colistin and rifampicin was fully synergistic against four A. baumannii and two P. aeruginosa strains. Combinations of colistin with meropenem and of colistin with azithromycin each showed synergistic activity against three A. baumannii isolates, whilst the same combinations resulted in generally additive or indifferent effects against P. aeruginosa strains. The colistin and doxycycline combination was generally partially synergistic or additive against all the isolates. MDR strains of P. aeruginosa and A. baumannii, which cause nosocomial infections with an increasing ratio in recent years, have limited treatment options. According to our in vitro study results, non-traditional antibiotics such as doxycycline and colistin can be an alternative for the treatment of infections caused by these strains. Combinations of colistin with non-traditional antibiotics or meropenem could be promising alternatives for the treatment of infections due to MDR strains of A. baumannii and P. aeruginosa. [Copyright &y& Elsevier]

Background: The best available treatment against carbapenemase-producing Enterobacteriaceae (CPE) is unknown. The objective of this study was to investigate the effect of appropriate therapy and of appropriate combination therapy on mortality of patients with bloodstream infections (BSIs) due to CPE.Methods: In this retrospective cohort study, we included patients with clinically significant monomicrobial BSIs due to CPE from the INCREMENT cohort, recruited from 26 tertiary hospitals in ten countries. Exclusion criteria were missing key data, death sooner than 24 h after the index date, therapy with an active antibiotic for at least 2 days when blood cultures were taken, and subsequent episodes in the same patient. We compared 30 day all-cause mortality between patients receiving appropriate (including an active drug against the blood isolate and started in the first 5 days after infection) or inappropriate therapy, and for patients receiving appropriate therapy, between those receiving active monotherapy (only one active drug) or combination therapy (more than one). We used a propensity score for receiving combination therapy and a validated mortality score (INCREMENT-CPE mortality score) to control for confounders in Cox regression analyses. We stratified analyses of combination therapy according to INCREMENT-CPE mortality score (0-7 [low mortality score] vs 8-15 [high mortality score]). INCREMENT is registered with ClinicalTrials.gov, number NCT01764490.Findings: Between Jan 1, 2004, and Dec 31, 2013, 480 patients with BSIs due to CPE were enrolled in the INCREMENT cohort, of whom we included 437 (91%) in this study. 343 (78%) patients received appropriate therapy compared with 94 (22%) who received inappropriate therapy. The most frequent organism was Klebsiella pneumoniae (375 [86%] of 437; 291 [85%] of 343 patients receiving appropriate therapy vs 84 [89%] of 94 receiving inappropriate therapy) and the most frequent carbapenemase was K pneumoniae carbapenemase (329 [75%]; 253 [74%] vs 76 [81%]). Appropriate therapy was associated with lower mortality than was inappropriate therapy (132 [38·5%] of 343 patients died vs 57 [60·6%] of 94; absolute difference 22·1% [95% CI 11·0-33·3]; adjusted hazard ratio [HR] 0·45 [95% CI 0·33-0·62]; p<0·0001). Among those receiving appropriate therapy, 135 (39%) received combination therapy and 208 (61%) received monotherapy. Overall mortality was not different between those receiving combination therapy or monotherapy (47 [35%] of 135 vs 85 [41%] of 208; adjusted HR 1·63 [95% CI 0·67-3·91]; p=0·28). However, combination therapy was associated with lower mortality than was monotherapy in the high-mortality-score stratum (30 [48%] of 63 vs 64 [62%] of 103; adjusted HR 0·56 [0·34-0·91]; p=0·02), but not in the low-mortality-score stratum (17 [24%] of 72 vs 21 [20%] of 105; adjusted odds ratio 1·21 [0·56-2·56]; p=0·62).Interpretation: Appropriate therapy was associated with a protective effect on mortality among patients with BSIs due to CPE. Combination therapy was associated with improved survival only in patients with a high mortality score. Patients with BSIs due to CPE should receive active therapy as soon as they are diagnosed, and monotherapy should be considered for those in the low-mortality-score stratum.Funding: Spanish Network for Research in Infectious Diseases, European Development Regional Fund, Instituto de Salud Carlos III, and Innovative Medicines Initiative. [ABSTRACT FROM AUTHOR]

Meticulous antimicrobial management is essential among critically ill patients with acute kidney injury, particularly if renal replacement therapy is needed. Many factors affect drug removal in patients undergoing continuous renal replacement therapy CRRT. In this study, we aimed to compare current databases that are frequently used to adjust CRRT dosages of antimicrobial drugs with the gold standard. The dosage recommendations from various databases for antimicrobial drugs eliminated by CRRT were investigated. The book 'Renal Pharmacotherapy: Dosage Adjustment of Medications Eliminated by the Kidneys' was chosen as the gold standard. There were variations in the databases. Micromedex, UpToDate, and Sanford had similar rates to the gold standard of 45%, 35%, and 30%, respectively. The Micromedex database shows the most similar results to the gold standard source. In addition, a consensus was reached as a result of the expert panel meetings established to discuss the different antimicrobial dose recommendations of the databases.

Objectives: Bloodstream infections caused by carbapenem-resistant bacteria have increased globally. Solid-organ transplant recipients are more prone to these infections. This study aimed to compare the clinical courses of carbapenem-susceptible and carbapenem-resistant Enterobacteriaceae bloodstream infections and to identify risk factors for carbapenem resistance in solid-organ transplant recipients., Materials and Methods: For this retrospective descriptive study, data for solid-organ transplant recipients (age ≥18) treated from 2015 to 2022 were obtained from medical records. Enterobacteriaceaepositive blood culture was screened from laboratory data., Results: Among 72 patients, there were 100 bacteremia episodes. Patients included 40 kidney (55.6%), 21 liver (29.2%), 7 heart (9.7%), and 4 combined liver and kidney (5.6%) transplant recipients. Fifty-seven bacteremia episodes were recorded between 2015 and 2020, and 43 bacteremia episodes were recorded between 2020 and 2022. Carbapenem resistance was reported in 15.8% of patients before 2020, whereas this rate increased to 39.5% after 2020 (P = .007). Pitt bacteremia score ≥4 (P < .001), Charlson comorbidity index ≥4 (P = .021), chronic liver disease (P = .015), septic shock at admission (P = .001), hypotension at admission (P = .006), bacteremia episodes 48 hours after hospitalization (P = .004), hospitalization in the past 3 months (P = .004), and prior invasive procedure (P = .043) were significant factors for carbapenem resistance. Logistic regression analysis showed that bacteremia 48 hours after hospitalization (P = .002) and hospitalization in the past 3 months (P = .006) were independent risk factors., Conclusions: Carbapenem resistance increased significantly over the years. Bacteremia 48 hours after hospitalization and hospitalization within the past 3 months were determined to be risk factors for carbapenem resistance. Carbapenem-resistant infections are still nosocomial infections. Patients should be hospitalized for as a short time as possible, and both patients and their physicians should follow infection control and prevention methods.

Background: Cefiderocol is generally active against carbapenem-resistant Klebsiella spp. (CRK) with higher MICs against metallo-beta-lactamase producers. There is a variation in cefiderocol interpretive criteria determined by EUCAST and CLSI. Our objective was to test CRK isolates against cefiderocol and compare cefiderocol susceptibilities using EUCAST and CLSI interpretive criteria., Methods: A unique collection ( n  = 254) of mainly OXA-48-like- or NDM-producing CRK bloodstream isolates were tested against cefiderocol with disc diffusion (Mast Diagnostics, UK). Beta-lactam resistance genes and multilocus sequence types were identified using bioinformatics analyses on complete bacterial genomes., Results: Median cefiderocol inhibition zone diameter was 24 mm (interquartile range [IQR] 24-26 mm) for all isolates and 18 mm (IQR 15-21 mm) for NDM producers. We observed significant variability between cefiderocol susceptibilities using EUCAST and CLSI breakpoints, such that 26% and 2% of all isolates, and 81% and 12% of the NDM producers were resistant to cefiderocol using EUCAST and CLSI interpretive criteria, respectively., Conclusions: Cefiderocol resistance rates among NDM producers are high using EUCAST criteria. Breakpoint variability may have significant implications on patient outcomes. Until more clinical outcome data are available, we suggest using EUCAST interpretive criteria for cefiderocol susceptibility testing.

Introduction. Aminoglycosides are used for the treatment of carbapenemase-producing Klebsiella pneumoniae (CPK) infections. 16S rRNA methyltransferases (RMTs) confer resistance to all aminoglycosides and are often cocarried with NDM. Hypothesis/Gap Statement. There is a dart of studies looking at the aminoglycoside resistance mechanisms for invasive CPK isolates, particularly in OXA-48 endemic settings. Aim. We aimed to determine the prevalence of RMTs and their association with beta lactamases and MLSTs amongst aminoglycoside-resistant CPK bloodstream isolates in an OXA-48 endemic setting. Methodology. CPK isolates ( n =181), collected as part of a multicentre cohort study, were tested for amikacin, gentamicin and tobramycin susceptibility using custom-made sensititre plates (GN2XF, Thermo Fisher Scientific). All isolates were previously subjected to whole-genome sequencing. Carbapenemases, RMTs, MLSTs and plasmid incompatibility groups were detected on the assembled genomes. Results. Of the 181 isolates, 109(60 %) were resistant to all three aminoglycosides, and 96 of 109(88 %) aminoglycoside-resistant isolates carried an RMT (85 ArmA, 10 RmtC, 4 RmtF1; three isolates cocarried ArmA and RmtC). Main clonal types associated with ArmA were ST2096 (49/85, 58 %) and ST14 (24/85, 28 %), harbouring mainly OXA-232 and OXA-48 +NDM, respectively. RmtC was cocarried with NDM (5/10) on ST395, and NDM +OXA-48 or NDM +KPC (4/10) on ST14, ST15 and ST16. All RMT producers also carried CTX-M-15, and the majority cocarried SHV-106, TEM-150 and multiple other antibiotic resistance genes. The majority of the isolates harboured a combination of IncFIB, IncH and IncL/M type plasmids. Non-NDM producing isolates remained susceptible to ceftazidime-avibactam. Conclusion. Aminoglycoside resistance amongst CPK bloodstream isolates is extremely common and mainly driven by clonal spread of ArmA carried on ST2096 and ST14, associated with OXA-232 and OXA48 +NDM carriage, respectively.

Vaccines have been seen as the most important solution for ending the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study is to evaluate the antibody levels after inactivated virus vaccination. We included 148 healthcare workers (74 with prior COVID-19 infection and 74 with not). They received two doses of inactivated virus vaccine (CoronaVac). Serum samples were prospectively collected three times (Days 0, 28, 56). We measured SARS-CoV-2 IgGsp antibodies quantitatively and neutralizing antibodies. After the first dose, antibody responses did not develop in 64.8% of the participants without prior COVID-19 infection. All participants had developed antibody responses after the second dose. We observed that IgGsp antibody titers elicited by a single vaccine dose in participants with prior COVID-19 infection were higher than after two doses of vaccine in participants without prior infection (geometric mean titer: 898 and 607 AU/ml). IgGsp antibodies, participants with prior COVID-19 infection had higher antibody levels as geometric mean titers at all time points (p < 0.001). We also found a positive correlation between IgGsp antibody titers and neutralizing capacity (r s  = 0.697, p < 0.001). Although people without prior COVID-19 infection should complete their vaccination protocol, the adequacy of a single dose of vaccine is still in question for individuals with prior COVID-19. New methods are needed to measure the duration of protection of vaccines and their effectiveness against variants as the world is vaccinated. We believe quantitative IgGsp values may reflect the neutralization capacity of some vaccines., (© 2021 Wiley Periodicals LLC.)