Ceftazidime–avibactam (CAZ-AVI) is an active antibiotic combination of a β-lactam–β-lactamase inhibitor against carbapenemase-producing Enterobacterales. Reports resistance to CAZ-AVI other than metallo-β-lactamases have increased in recent years. The aim this study was analyze KPC-Klebsiella pneumoniae (KP) isolates resistant from the intestinal carriage hospitalized elderly patients Italy, Fe...

The Yfe/Sit and Feo transport systems are important for the growth of a variety of bacteria. In Yersinia pestis, single mutations in either yfe or feo result in reduced growth under static (limited aeration), iron-chelated conditions, while a yfe feo double mutant has a more severe growth defect. These growth defects were not observed when bacteria were grown under aerobic conditions or in stra...

UNLABELLED Highly invasive, community-acquired Klebsiella pneumoniae infections have recently emerged, resulting in pyogenic liver abscesses. These infections are caused by hypervirulent K. pneumoniae (hvKP) isolates primarily of capsule serotype K1 or K2. Hypervirulent K1 isolates belong to clonal complex 23 (CC23), indicating that this clonal lineage has a specific genetic background conferri...

BACKGROUND Whether accessory traits, phylogenetic background, or ecological source best predicts extraintestinal virulence within Escherichia coli is undefined. METHODS A total of 90 E. coli strains (18 fecal isolates and 72 extraintestinal-infection isolates) were characterized for 55 accessory traits and phylogenetic group (A, B1, B2, or D). Bacterial traits and ecological source were compa...

Ferric iron is transported into Escherichia coli by a number of chelating compounds. Iron transport through the outer membrane by citrate, ferrichrome, enterobactin, aerobactin, yersiniabactin, and heme is catalyzed by highly specific proteins and across the cytoplasmic membrane by ABC transport systems with lower specificity. Transport across the outer membrane requires energy, which is provid...

In this study, we determined the function of a novel non-ribosomal peptide synthetase (NRPS) system carried by a streptococcal integrative conjugative element (ICE), ICESe2. The NRPS shares similarity with the yersiniabactin system found in the high-pathogenicity island of Yersinia sp. and is the first of its kind to be identified in streptococci. We named the NRPS product 'equibactin' and gene...

Iron acquisition is an important aspect of the host-pathogen interaction. In the case of Salmonella it is established that catecholate siderophores are important for full virulence. In view of their very high affinity for ferric iron, functional studies of siderophores have been almost exclusively focused on their role in acquisition of iron from the host. In the present study, we investigated ...

BACKGROUND Colibactin is a nonribosomal peptide-polyketide synthesized by multi-enzyme complexes encoded by the pks gene cluster. Colibactin-producing Escherichia coli have been demonstrated to induce host DNA damage and promote colorectal cancer (CRC) development. In Taiwan, the occurrence of pyogenic liver abscess (PLA) has been suggested to correlate with an increasing risk of CRC, and Klebs...

The high-pathogenicity island (HPI) of yersiniae encodes an iron uptake system represented by its siderophore yersiniabactin (Ybt). The HPI is present in yersiniae with high levels of pathogenicity--i.e., Yersinia pestis, Y. pseudotuberculosis, and Y. enterocolitica biogroup (BG) 1B--but absent in Y. enterocolitica strains with low (BG 2 to 5) and no (BG 1A) levels of pathogenicity and has been...