Susceptibility of Gram-negative pathogens collected in Israel to ceftolozane/tazobactam, imipenem/relebactam and comparators: SMART 2018-22.

Objectives: To assess the antimicrobial activity of ceftolozane/tazobactam, imipenem/relebactam and comparator agents against clinical isolates of Gram-negative bacilli collected in Israel from 2018 to 2022.

Methods: Six clinical laboratories each collected up to 250 consecutive Gram-negative isolates per year from patients with bloodstream, intra-abdominal, lower respiratory tract and urinary tract infections. MICs were determined by CLSI broth microdilution and interpreted with 2024 EUCAST breakpoints.

Cefepime-taniborbactam activity against antimicrobial-resistant clinical isolates of Enterobacterales and Pseudomonas aeruginosa: GEARS global surveillance programme 2018-22.

Objectives: Taniborbactam is a boronate-based β-lactamase inhibitor in clinical development in combination with cefepime.

Methods: Cefepime-taniborbactam and comparator broth microdilution MICs were determined for patient isolates of Enterobacterales (n = 20 725) and Pseudomonas aeruginosa (n = 7919) collected in 59 countries from 2018 to 2022. Taniborbactam was tested at a fixed concentration of 4 mg/L.

activity of ceftazidime-avibactam and comparators against OXA-48-like Enterobacterales collected between 2016 and 2020.

Unlabelled: Oxacillinases (OXA)-48-like β-lactamases are one of the most common resistance determinants among carbapenem-resistant Enterobacterales reported globally. Moreover, there is no standard treatment available against organisms producing OXA-48-like enzymes, and they are sometimes difficult to detect, making treatment challenging. The objective of this study was to evaluate the distribution and antimicrobial susceptibility of Enterobacterales isolates against ceftazidime-avibactam (CAZ-AVI) and a panel of comparators collected worldwide from 2016 to 2020 as a part of the Antimicrobial Testing Leadership and Surveillance program.

Susceptibility of Gram-negative isolates collected in South Korea to imipenem/relebactam and comparator agents-SMART 2018-21.

Objectives: To evaluate the susceptibility of recent Gram-negative pathogens collected in South Korean medical centres to imipenem/relebactam and comparator agents.

Methods: From 2018 to 2021, six hospitals in South Korea each collected up to 250 consecutive, aerobic or facultative Gram-negative pathogens per year from patients with bloodstream, intra-abdominal, lower respiratory tract and urinary tract infections. MICs were determined using CLSI broth microdilution and interpreted by 2023 CLSI breakpoints.

Susceptibility of gram-negative isolates collected in Taiwan to imipenem/relebactam and comparator agents - SMART 2018-2021.

Background: Imipenem/relebactam (IMR) was approved for patient use in Taiwan in 2023. We evaluated the in vitro susceptibility of recent Gram-negative pathogens collected in Taiwan hospitals to IMR and comparators with a focus on carbapenem-resistant and KPC-carrying non-Morganellaceae Enterobacterales (NME), and carbapenem-resistant Pseudomonas aeruginosa (CRPA).

Methods: From 2018 to 2021, eight hospitals in Taiwan each collected up to 250 consecutive, aerobic or facultative, Gram-negative pathogens per year from patients with bloodstream, intraabdominal, lower respiratory tract, and urinary tract infections.

In vitro activity of aztreonam-avibactam against Enterobacterales isolates collected in Latin America, Africa/Middle East, Asia, and Eurasia for the ATLAS Global Surveillance Program in 2019-2021.

This study aimed to report reference method antimicrobial susceptibility results for 24,937 recent (2019-2021) clinical isolates of Enterobacterales from 27 countries in Latin America, Eurasia, Africa/Middle East, and Asia with a focus on the investigational combination aztreonam-avibactam against metallo-β-lactamase (MBL) isolates. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution methodology. Minimum inhibitory concentrations (MICs) were interpreted using the CLSI (2022) breakpoints for all agents except aztreonam-avibactam (provisional pharmacokinetic/pharmacodynamic susceptible breakpoint, ≤ 8 mg/L) and tigecycline (US-FDA).

Temporal and geographical prevalence of carbapenem-resistant Pseudomonas aeruginosa and the in vitro activity of ceftolozane/tazobactam and comparators in Taiwan-SMART 2012-2021.

Objectives: To determine the in vitro activities of ceftolozane/tazobactam (C/T) and comparators against Pseudomonas aeruginosa isolates cultured from hospitalised patient samples in Taiwan from 2012 to 2021 with an additional focus on the temporal and geographical prevalence of carbapenem-resistant P. aeruginosa (CRPA).

Methods: P.

In vitro activity of cefiderocol against MBL-producing Gram-negative bacteria collected in North America and Europe in five consecutive annual multinational SIDERO-WT surveillance studies (2014-2019).

Objectives: To evaluate the in vitro antibacterial activity of cefiderocol, a siderophore cephalosporin against MBL-producing clinical isolates.

Methods: MBL-producing strains were selected from clinical isolates of Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii complex collected in North America and Europe in five consecutive annual multinational SIDERO-WT surveillance studies from 2014 to 2019. MICs of cefiderocol and comparator agents were determined by the broth microdilution method according to the CLSI guideline.

Activity of Cefiderocol Against Meropenem-Nonsusceptible Gram-Negative Bacilli with Defined β-Lactamase Carriage: SIDERO-WT Surveillance Studies, 2014-2019.

We examined the susceptibility of meropenem-nonsusceptible Enterobacterales, , and complex isolates from five consecutive annual SIDERO-WT surveillance studies (2014-2019) to cefiderocol and comparator agents in the context of their carbapenemase carriage. 1,003 Enterobacterales, 1,758 , and 2,809 complex isolates from North America and Europe that were meropenem nonsusceptible (CLSI M100, 2022) were molecularly characterized for β-lactamase content by PCR followed by Sanger sequencing or by whole genome sequencing. Among Enterobacterales, 91.

Incidence of ESBLs and carbapenemases among Enterobacterales and carbapenemases in Pseudomonas aeruginosa isolates collected globally: results from ATLAS 2017-2019.

Objectives: To assess the global and regional distribution of ESBLs in Enterobacterales and carbapenemases in Enterobacterales and Pseudomonas aeruginosa.

Methods: Antimicrobial susceptibility of isolates collected from ATLAS (2017-2019) was determined per CLSI guidelines. Enterobacterales exhibiting meropenem MICs ≥2 mg/L and/or ceftazidime/avibactam and/or aztreonam/avibactam MICs ≥16 mg/L, Escherichia coli and Klebsiella pneumoniae with aztreonam and/or ceftazidime MICs ≥2 mg/L, and P.

Epidemiology and in vitro activity of ceftazidime-avibactam and comparator agents against multidrug-resistant isolates of Enterobacterales and Pseudomonas aeruginosa collected in Latin America as part of the ATLAS surveillance program in 2015‒2020.

Introduction: The incidence of antimicrobial resistance is increasing in many parts of the world. The focus of this report is to examine changes in antimicrobial resistance epidemiology among clinical isolates of Enterobacterales and Pseudomonas aeruginosa collected in six Latin American countries as part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) program from 2015 to 2020, with a focus on the in vitro activity of ceftazidime-avibactam against Multidrug-Resistant (MDR) isolates.

Methods: Non-duplicate, clinical isolates of Enterobacterales (n = 15,215) and P.

Multicenter Evaluation of the Acuitas AMR Gene Panel for Detection of an Extended Panel of Antimicrobial Resistance Genes among Bacterial Isolates.

The Acuitas antimicrobial resistance (AMR) gene panel is a qualitative, multiplex, nucleic acid-based diagnostic test for the detection and differentiation of 28 antimicrobial resistance markers associated with not susceptible results (NS; i.e., intermediate or resistant) to one or more antimicrobial agents among cultured isolates of select , Pseudomonas aeruginosa, and Enterococcus faecalis.

Molecular characterization of clinical isolates of Enterobacterales with elevated MIC values for aztreonam-avibactam from the INFORM global surveillance study, 2012-2017.

Objectives: While aztreonam-avibactam is a potent β-lactam-β-lactamase-inhibitor combination, reduced in vitro activity against some Enterobacterales isolates has been reported. In this study, globally collected clinical isolates of Enterobacterales with elevated minimum inhibitory concentrations (MICs) for aztreonam-avibactam were examined for potential resistance mechanisms.

Methods: Isolates with aztreonam-avibactam MICs ≥8 μg/mL (n = 55: Escherichia coli, n = 38; Enterobacter cloacae, n = 10; Klebsiella pneumoniae, n = 3; others, n = 4) and <8 μg/mL (n = 18) collected for the INFORM global surveillance programme were characterized by short read whole-genome sequencing.

Multicenter evaluation of the RAPIDEC® CARBA NP assay for the detection of carbapenemase production in clinical isolates of Enterobacterales and Pseudomonas aeruginosa.

Carbapenem-resistant Gram-negative bacilli are a major public health problem. Accurate and rapid detection of carbapenemase-producing organisms can facilitate appropriate infection prevention measures. The objective was to evaluate the performance of the RAPIDEC® CARBA NP assay (RAPIDEC), a screening assay that utilizes a pH indicator to detect carbapenem hydrolysis within 2 h.

Growth and Reproductive Performance of Rangeland Beef-Cattle as Influenced by Controlled and Uncontrolled Populations of Horn Flies (Diptera: Muscidae).

A 4-yr study was conducted on native rangeland to assess the growth and reproductive performance of cows (Bos taurus) infested with naturally occurring seasonal populations of horn flies (Haematobia irritans). One hundred five Angus × Hereford cow-calf pairs were evaluated as a randomized complete block that was replicated across 4 yr. Cows were approximately 39 d postpartum at the beginning of each yearly trial and were randomly allocated to either an untreated control (UTC) or an insecticide-treated (TRT) herd.

In vitro activity of cefiderocol, a siderophore cephalosporin, against a recent collection of clinically relevant carbapenem-non-susceptible Gram-negative bacilli, including serine carbapenemase- and metallo-β-lactamase-producing isolates (SIDERO-WT-2014 Study).

Cefiderocol is a siderophore cephalosporin in development for treatment of infections caused by Gram-negative bacilli, including carbapenem-resistant and multidrug-resistant isolates. β-Lactamase carriage and in vitro activity of cefiderocol were determined against 1272 meropenem-non-susceptible isolates of Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii collected as part of the SIDERO-WT-2014 surveillance study. Minimum inhibitory concentration (MIC) values for cefiderocol were ≤4 µg/mL against 97.

Prevalence of mcr-type genes among colistin-resistant Enterobacteriaceae collected in 2014-2016 as part of the INFORM global surveillance program.

A set of 908 clinically derived colistin-resistant Enterobacteriaeae isolates collected worldwide in 2014-2016 were screened for the presence of the plasmid-borne mcr-1, mcr-2, mcr-3, mcr-4 and mcr-5 genes. In total 3.2% (29/908) of the collection were positive for mcr, including 27 Escherichia coli, 1 Klebsiella pneumoniae and 1 Enterobacter cloacae.

Global survey of Klebsiella pneumoniae major porins from ertapenem non-susceptible isolates lacking carbapenemases.

Purpose: To understand the diversity of porin disruption in Klebsiella pneumoniae, the major outer membrane protein (OMP) porins, OmpK35 and OmpK36, were examined in a set of isolates that did not harbour traditional carbapenem-hydrolysing enzymes, but nevertheless tested non-susceptible to ertapenem.

Methods: A world-wide collection of Klebsiella pneumoniae isolates that were part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance project over the years 2008-2014 were characterised with regard to their β-lactamase gene carriage and potential permeability defects. Four hundred and eighty-seven isolates that did not carry carbapenemase genes, but were non-susceptible to ertapenem, were investigated by sequence analysis of the genes encoding OmpK35 and OmpK36.

Behavioral Responses of Cattle to Naturally Occurring Seasonal Populations of Horn Flies (Diptera: Muscidae) Under Rangeland Conditions.

The behavioral responses of cattle under the influence of naturally occurring seasonal horn fly, Haematobia irritans (L.), populations were evaluated under rangeland conditions. This study was replicated four times using 10 cows as the subsampling unit equipped with GPS collars scheduled to receive locational fixes every 5 min for 6 d prior to, and 6 d following horn fly insecticidal control application.