Oxacillinase

In 2019-2022, a prolonged outbreak of oxacillinase (OXA)-48-producing Citrobacter farmeri due to a persistent environmental contamination, occurred in our haematology intensive care unit. In April 2019, we isolated OXA-48-producing C. farmeri from rectal samples of two patients in weekly screenings. The cases had stayed in the same hospital room but 4 months apart. We screened five patients who had stayed in this room between the two cases and identified a third case. Over the following 3 years, five other cases were detected, the last case in September 2022...

BACKGROUND: Biapenem (BIPM) exhibited a less efficient substrate for various Metallo-β-lactamase (MBL) than other carbapenems. OBJECTIVE: We aimed to evaluate in vitro susceptibility data of BIPM, and optimal dose based on Monte Carlo simulation to extend treatment options. METHODS: We collected 192 carbapenem-resistant Klebsiella pneumoniae (CRKP) clinical isolates from unique patients among multicenters in Thailand, from June 2019-March 2023...

Antibiotics are still used to treat mastitis in dairy cows in Indonesia. This study aimed to analyse antibiotic resistance genes in  Escherichia coli ( E. coli ) from subclinical mastitis milk in East Java Province, Indonesia. The samples consisted of subclinical mastitis milk from cows and goats. A total of 592-quarter cow's milk and 71 goat's milk samples from both halves of the udder were collected from 67 farms in Lumajang, Banyuwangi, Malang, Sidoarjo, Jember, Pasuruan, Probolinggo, and Mojokerto...

OBJECTIVE: In recent years, Acinetobacter baumannii has been appearing in hospitals with high drug resistance and strong vitality, which brings many difficulties to clinical treatment. In this study, 255 strains of A. baumannii were isolated from Youjiang Medical University for Nationalities Affiliated Hospital clinical samples and found to be highly resistant to carbapenems. The drug resistance, biofilm-forming ability, and carbapenase gene distribution of 145 carbapenem-resistant A...

UNLABELLED: Carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter spp. represent major threats and have few approved therapeutic options. Non-‍fermenting Gram-negative isolates were collected from hospitalized inpatients from 49 sites in 6 European countries between 01 January 2020 and 31 December 2020 and underwent susceptibility testing against cefiderocol and β-lactam/β-lactamase inhibitor combinations. Meropenem-resistant (MIC >8 mg/L), cefiderocol-susceptible isolates were analyzed by PCR, and cefiderocol-resistant isolates were analyzed by whole-genome sequencing to identify resistance mechanisms...

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 bla OXA-48-like 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...

ANT3310 is a novel broad-spectrum diazabicyclooctane serine β-lactamase inhibitor being developed in combination with meropenem (MEM) for the treatment of serious infections in hospitalized patients where carbapenem-resistant Gram-negative pathogens are expected. In this study, we evaluated the in vitro antibacterial activity of MEM in the presence of ANT3310 at 8 µg/mL against global clinical isolates that included Acinetobacter baumannii ( n = 905), carbapenem-resistant Enterobacterales (CRE), carrying either oxacillinase (OXA) ( n = 252) or Klebsiella pneumoniae carbapenemase (KPC) ( n = 180) carbapenemases, and Pseudomonas aeruginosa ( n = 502)...

Antibiotic-resistant Enterobacterales that produce oxacillinase (OXA)-48-like Class D β-lactamases are often linked to increased clinical mortality. Though the catalytic mechanism of OXA-48 is known, the molecular origin of its biphasic kinetics has been elusive. We here identify selective chloride binding rather than decarbamylation of the carbamylated lysine as the source of biphasic kinetics, utilizing isothermal titration calorimetry (ITC) to monitor the complete reaction course with the OXA-48 variant having a chemically stable N -acetyl lysine...

Multi-drug resistant (MDR) Acinetobacter baumannii is emerging as a pathogen of increasing prevalence and concern. Infections associated with this Gram-negative pathogen are often associated with increased morbidity and mortality and few therapeutic options. The β-lactamase inhibitor sulbactam used commonly in combination with ampicillin demonstrates intrinsic antibacterial activity against A. baumannii acting as an inhibitor of PBP1 and PBP3, which participate in cell wall biosynthesis. The production of β-lactamases, particularly class D oxacillinases, however, has limited the utility of sulbactam resorting to increased doses and the need for alternate therapies...

PURPOSE: This study investigated the clinical and antimicrobial characteristics of Acinetobacter spp. bloodstream infection (BSI) in hematological patients. Risk factors for 30-day mortality and carbapenem-resistant Acinetobacter spp. (CRA) BSI acquisition were also identified. METHODS: We reviewed forty hematological patients with Acinetobacter spp. BSI in a large Chinese blood disease hospital between 2013 and 2022. The remaining CRA isolates were subjected to whole-genome sequencing...

BACKGROUND AND OBJECTIVES: Detecting the source of a potential outbreak of multidrug resistant (MDR) Acinetobacter baumannii is necessary to be investigated. This study aimed to detect the possibility of A. baumannii outbreak in a hospital setting using a combination of random amplified polymorphism DNA-polymerase chain reaction (RAPD-PCR), antibiograms, and the presence of oxacillinase genes. MATERIALS AND METHODS: The antibiogram of 31 clinical isolates and six environmental isolates of A...

INTRODUCTION: Non- baumannii Acinetobacter species are increasingly isolated in the clinical setting and the environment. The aim of the present study was to analyze a genome database of 837 Acinetobacter spp. isolates, which included 798 non- baumannii Acinetobacter genomes, in order to define the concordance of classification and discriminatory power of 7-gene MLST, 53-gene MLST, and single-nucleotide polymorphism (SNPs) phylogenies. METHODS: Phylogenies were performed on Pasteur Multilocus Sequence Typing (MLST) or ribosomal Multilocus Sequence Typing (rMLST) concatenated alleles, or SNPs extracted from core genome alignment...

Acinetobacter baumannii is one of the pathogens most involved in health care-associated infections in recent decades. Known for its ability to accumulate several antimicrobial resistance mechanisms, it possesses the oxacillinase bla oxa-23 , a carbapenemase now endemic in Italy. Acinetobacter species are not frequently observed in patients with cystic fibrosis, and multidrug-resistant A. baumannii is a rare event in these patients. Non-mucoid A. baumannii carrying the bla oxa-23 gene has been sporadically detected...

Antibiotic resistance in uropathogens has increased substantially and severely affected treatment of urinary tract infections (UTIs). Lately, some new formulations, including meropenem/vaborbactam (MEV), ceftazidime/avibactam (CZA), and ceftolozane/tazobactam (C/T) have been introduced to treat infections caused by drug-resistant pathogens. This study was designed to screen Enterobacteriales isolates from UTI patients and to assess their antimicrobial resistance pattern, particularly against the mentioned (new) antibiotics...

OBJECTIVES: The prevalence of carbapenem-resistant Enterobacterales (CRE) presents a significant challenge in clinical anti-infective treatment. This study aims to investigate drug resistance and the molecular epidemiological characteristics of CRE in our area. Additionally, we seek to evaluate practicality of utilizing carbapenemase inhibitor enhancement test in clinical laboratory. METHODS: Non-repeated CREs isolated from clinical specimens at Xiangya Hospital, Central South University, were collected...

Acinetobacter baumannii is an opportunistic pathogen responsible for healthcare-associated infections (HAIs) and outbreaks. Antimicrobial resistance mechanisms and virulence factors allow it to survive and spread in the hospital environment. However, the molecular mechanisms of these traits and their association with international clones are frequently unknown in low- and middle-income countries. Here, we analyze the phenotype and genotype of seventy-six HAIs and outbreak-causing A. baumannii isolates from a Mexican hospital over ten years, with special attention to the carbapenem resistome and biofilm formation...

The emergence of carbapenem-resistant Enterobacterales (CRE) has been recognized as a significant concern globally. Ceftazidime/avibactam (CZA) is a novel β-lactam/β-lactamase inhibitor that has demonstrated activity against isolates producing class A, C, and D β-lactamases. Here-in, we evaluated the in vitro activity of CZA and comparator antimicrobial agents against 858 CRE isolates, arising from the Southeast Asian region, collected from a large tertiary hospital in Singapore. These CRE isolates mainly comprised Klebsiella pneumoniae (50...

INTRODUCTION AND BACKGROUND: Rapid molecular diagnostics to predict carbapenem resistance well before the availability of routine drug sensitivity testing (DST) can serve as an antimicrobial stewardship tool in the context of high rates of Carbapenem-resistant Enterobacteriaceae (CRE). MATERIALS AND METHODS: A retrospective observational study of patients more than 18 years of age on whom Xpert Carba-R (FDA approved for rectal swab specimen) was done on gram-negative bacteria (GNB) flagged blood culture samples, in an Indian intensive care unit between January 2015 and November 2018...

In the Philippines, data are scarce on the co-occurrence of multiple β-lactamases (BLs) in clinically isolated Gram-negative bacilli. To investigate this phenomenon, we characterized BLs from various β-lactam-resistant Klebsiella pneumoniae , Escherichia coli , Acinetobacter baumannii , and Pseudomonas aeruginosa isolated from a Philippine tertiary care hospital. The selected Gram-negative bacilli ( n = 29) were resistant to either third-generation cephalosporins (resistance category 1 (RC1)), cephalosporins and penicillin-β-lactamase inhibitors (RC2), or carbapenems (RC3)...

INTRODUCTION:  Carbapenem resistance in Acinetobacter baumannii  ( A. baumannii ) is a public health problem worldwide. Although carbapenem resistance is emerging in Morocco, few studies have shown the epidemiological profile of carbapenemase genes in Moroccan healthcare facilities. The aim of this study was to characterize the molecular profile of the carbapenemase enzyme in Acinetobacter baumannii from clinical isolates. METHODS: Clinical strains isolated in the laboratory from various samples were subjected to several phenotypic tests...