Biology subjects

Ibaguren-Quiles, C.

Publications and source records attributed to Ibaguren-Quiles, C..

3 recordsLinked to original sources

bioRxiv2025

Identification and Functional Insights into New Phage Tail-Like Bacteriocins (PTLBs) Targeting Pseudomonas aeruginosa as new antimicrobials

The current health crisis caused by multidrug resistant (MDR) pathogens is one of the health problems of most concern globally. Infections caused by these pathogens, such as Pseudomonas aeruginosa, lead to high rates of complications, particularly in compromised patients such as cystic fibrosis (CF) patients. The need to counteract and minimize the forecast future impact has led to the rescue of phage therapy. The use of bacteriophages has important advantages, including highly specific targeting, self-amplification at the infection site, minimal disruption of the microbiome, safety and biocompatibility. However, the capacity of bacteria to escape these entities results in a form of resistance that compromises the effectiveness of the therapy. This involves the search for potential alternatives, such as the phage tail-like bacteriocins (PTLBs), also named as tailocins. These high molecular weight particles resemble the tail structure of bacteriophages and are characterized by the absence of genetic material, avoiding the development of resistance, one of the major handicaps associated with phage therapy. In this study, we detected 34 different PTLBs in 75 P. aeruginosa genomes, with different serotypes and sequence types, 11 of which were characterized as novel F-type PTLBs subtypes (F13-F24). Furthermore, we report that four selected PTLBs (R1, F15, F19, R3-F24) can deal with bacterial infection, with the R1 and the F15 PTLBs being the most efficient in clearing infection in vitro, yielding a survival rate of more than 75% in the Galleria mellonella larvae in vivo model. This reaffirms the potential of PTLBs to control P. aeruginosa infections, which can cause chronic infections in some patients, such as people with CF, due to its strong impact as a MDR bacterium. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=194 HEIGHT=200 SRC="FIGDIR/small/671207v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@76b60borg.highwire.dtl.DTLVardef@1a9cd0aorg.highwire.dtl.DTLVardef@d45dd0org.highwire.dtl.DTLVardef@5b345a_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTS-The 75 Pseudomonas aeruginosa genomes from people with cystic fibrosis in the study collection included at least one Phage tail-like bacteriocins (PTLB) cluster. -From the 34 different PTLBs detected in the study collection, 7 were R-type, 10 were complex (R and F-type encoded) and 14 were F-type PTLBs. -11 new F-type PTLBs were described in the Pseudomonas aeruginosa collection under study. -An association between the O-antigen present on the surface of the Pseudomonas aeruginosa isolate and the encoded PTLB subtype was detected. -The R1 and F15 PTLBs subtypes display high antimicrobial activity both in vitro and in vivo (Galleria mellonella).

microbiology↗

bioRxiv2024

The LAMP-CRISPR-Cas13a technique for detecting CBASS-mechanism of phage resistance in bacteria

Antimicrobial resistance (AMR) is an important threat to public health that has led to the development of innovative alternative treatments for bacterial infections, such as phage therapy. However, one of the greatest disadvantages of phage therapy is the generation of phage-resistant bacterial mutants via bacterial defence mechanisms, which are mainly contained in genomic islands (GIs) and controlled by the quorum sensing (QS) network. In this study, 309 pathogenic islands (PAIs) harbouring a total of 22.1 % of proteins related to anti-phage defence (APD) were detected in the genome of 48 K. pneumoniae strains. Several type I and type II CBASS systems were also detected in the genome of the 48 K. pneumoniae strains, but only 2 type II CBASS systems were located in PAIs. We constructed a knockout K. pneumoniae strain, not expressing the cyclase gene from the type II CBASS system present in PAIs, to study the regulatory role of QS in expressing the gene. As the anti-phage CBASS system is an abortive infection (Abi) system, the role of the type II CBASS system in regulating cell viability was assessed. The knockout strain was confirmed by targeting the LAMP-CRISPR-Cas13a technique specifically to the cyclase gene, and the same protocol was also used to detect the gene of the main cyclase in these type I CBASS systems, i.e. APECO1. The study findings demonstrate the regulatory role of the QS network in anti-phage defence systems. Finally, this is the first work which development an innovative biotechnological application for the LAMP-CRISPR-Cas13a rapid-technique (<2 hours) in optimizing phage therapy by detecting bacterial resistance mechanisms, by predicting the potential inefficacy of a therapeutic phage and thus improving patient prognosis.

microbiology↗

bioRxiv2024

Studies in vitro e in vivo of Phage Therapy Medical Products (PTMPs) targeting clinical strains of Klebsiella pneumoniae belonging to the clone ST512

The widespread incidence of antimicrobial resistance has created renewed interest in the use of alternative antimicrobial treatments such as phage therapy. Phages are viruses that infect bacteria and generally have a narrow bacteria host-range. Combining phages with antibiotics can prevent the emergence of bacterial resistance. The aim of the present study was to develop phage therapy medical products (PTMPs) targeting clinical isolates of carbapenems-producing Klebsiella pneumoniae belonging to the high-risk clone ST512. From a collection of twenty-two seed of lytic phages sequenced belonging to MePRAM collection, four were used to generate PTMPs (CAC_Kpn1 and CAC_Kpn2). These PTMPs were partly active against three of the clinical strains of clone ST512 (A, B and C). The use of Appelmans method in the CAC_Kpn1_ad (adapted CAC_Kpn1) yielded a significant increase in the efficacy against strain A, while adapted CAC_Kpn2 (CAC_Kpn2_ad) only effectively reduced bacterial survival when combined with [1/2] x MIC {beta}-lactam antibiotic meropenem for 24 h in clinical strains B and C, showed after this time, resistance to PTMPs. In addition, the amounts of endotoxin released by the PTMPs were quantified and subsequently reduced in preparation for in vivo use of the PTMPs in Galleria mellonella infection model confirming the in vitro results from the CAC_Kpn1_ad and CAC_Kpn2_ad.

microbiology↗