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A topical collection in Antibiotics (ISSN 2079-6382). This collection belongs to the section "Antibiofilm Strategies".

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Editors

Dr. Ding-Qiang Chen

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Guest Editor

Department of Laboratory Medicine, Southern Medical University, Guangzhou, China
Interests: antimicrobial resistance; clinical microbiology; mechanisms for microbial drug resistance

Prof. Dr. Yulong Tan

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Guest Editor

1. Department of Otorhinolaryngology and Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
2. Special Food Research Institute, Qingdao Agricultural University, Qingdao 266109, China
Interests: seafood-borne pathogens; seafood-borne spoilage microorganims; antibiotic residues; heavy metal residues; rapid detection techniques
Special Issues, Collections and Topics in MDPI journals

Dr. Ren-You Gan

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Guest Editor

Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science Technology and Research (A*STAR), 30 Medical Drive, Singapore 117609, Singapore
Interests: phytochemicals; probiotics; prebiotics; gut microbiota; nutrition; functional food
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Guanggang Qu

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Guest Editor

Shandong Binzhou Animal Science & Veterinary Medicine Academy, Binzhou National Economic and Technological Development Zone, No. 169 2nd Huanghe Road, Binzhou 256600, China
Interests: preventive veterinary medicine; veterinary biotechnology and biological products

Dr. Zhenbo Xu

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Guest Editor

School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China
Interests: biofilm; foodborne microorganisms; antimicrobial resistance; pathogenicity and virulence; stress response; quorum sensing; polymicrobial interaction
Special Issues, Collections and Topics in MDPI journals

Dr. Junyan Liu

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Guest Editor

College of Light Industry and Food Science, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
Interests: antimicrobial resistance; biofilms; viable but non-culturable (VBNC) and persistence; stress response; polymicrobial interaction
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

This Topical Collection is created in cooperation with Asia-Pacific Biofilms (www.asiapacificbiofilms.org), one of the three major international conferences in the field of biofilms along with EuroBiofilms and ASM Biofilms. We welcome advanced research articles and reviews related to antimicrobial resistance and anti-biofilms. There are three major research avenue of this Topical Collection, described below.

1. Antimicrobial resistance in microorganisms: epidemiology and molecular mechanism (led by Dr. Dingqiang Chen)

The emergence and worldwide spread of antimicrobial resistance in microorganisms is a significant threat to human health. The epidemiology of infection by resistant microbes is still not clear in many areas. Investigating the underlying mechanisms of antimicrobial resistance is important for the control of infections caused by resistant microorganisms.

This research avenue seeks manuscript submissions that can improve our understanding of the epidemiology and molecular mechanism on antimicrobial resistance. Manuscripts regarding the prevalence of resistant microbes, the emergence and evolution of resistance, and the molecular investigation of resistance mechanisms, such as genomic or proteomic analysis, are welcome.

2. New antibiofilm strategy against fungal and/or bacterial biofilms (led by Dr. Yulong Tan)

Microorganisms in nature produce biofilms to resist the pressures of the environment. The outer layer of the mature biofilm is a polysaccharide protein complex secreted by bacteria, and the inner layer is the coated bacteria. Bacterial biofilm formation is a dynamic process, which is mainly divided in four stages—initial adhesion, irreversible adhesion, aggregation, and development and abscission. Biofilms can protect microbial cells from antibiotics, chlorine, detergent, host immune defense mechanism, and other factors. The resistance of microbes to antimicrobial substances in biofilms is 10 times or even 1000 times higher than that of planktonic mode. At present, the conventional chemical or physical methods are unable to completely remove biofilms. Traditional antibiotics can kill the cells inside, but thye will cause drug resistance. In addition, the "inactive" biofilm structure can still promote the adhesion and regeneration of the biofilms of other microorganisms. Therefore, in addition to the microbial cells in thin biofilms, the biofilm matrix itself should also be a target. As a result, novel antibiofilm strategies that are able to interfere with cells inside and disassemble the biofilm matrix are needed in order to inhibit biofilm formation and/or disrupt persistent biofilms. At present, the study of biofilm formation and antibiofilm strategies has been of utmost importance in scientific research.

3. Influence of Functional Material-Based Encapsulation/Delivery on the Antimicrobial and Antivirulent Effects of Natural Compounds (led by Dr. Renyou Gan)

Many natural compounds exhibit antimicrobial and antivirulent effects. Different functional materials, such as nanoparticles (e.g., lipid-based, polymer-based, carbohydrate-based, protein-based, metal-based, and nucleic acid-based nanoparticles), hydrogels, as well as micro/nano emulsions and packaging materials, can be used to encapsulate/deliver natural compounds and further enhance their antimicrobial and antivirulent effects. Therefore, understanding the antimicrobial and antivirulent effects of these functional material-encapsulated/delivered natural compounds as well as their underlying mechanism of action can provide a scientific basis for their further applications as antibiotic alternatives.

This research avenue seeks manuscript submissions that can improve our understanding of the influence of functional material-based encapsulation/delivery on the antimicrobial and antivirulent effects of natural compounds. Manuscripts regarding the production and characteristics of these functional material-encapsulated/delivered natural compounds, their in vitro and in vivo antimicrobial and antivirulent effects, and their potential applications, such as in food and medicine, are welcome.

Dr. Ding-Qiang Chen
Dr. Yulong Tan
Dr. Ren-You Gan
Prof. Dr. Guanggang Qu
Prof. Dr. Zhenbo Xu
Dr. Junyan Liu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Antibiotics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (13 papers)

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2023

Jump to: 2022, 2021

9 pages, 1031 KiB

Open AccessPerspective

The Role of Biofilms in Contact Lens Associated Fungal Keratitis

by Jipan Yi, Yao Sun, Chenghong Zeng, Xenia Kostoulias and Yue Qu

Antibiotics 2023, 12(10), 1533; https://doi.org/10.3390/antibiotics12101533 - 12 Oct 2023

Cited by 3 | Viewed by 2306

Abstract

Biofilm formation is an important microbial strategy for fungal pathogens, such as Fusarium, Aspergillus, and Candida, to establish keratitis in patients wearing soft contact lenses. Despite the well-documented 2006 outbreak of Fusarium keratitis that eventually led to the withdrawal of the Bausch & Lomb multipurpose lens care solution ReNu with MoistureLoc (“MoistureLoc”) from the global market, contact lens care systems and solutions currently available on the market do not specifically target fungal biofilms. This is partially due to the lack of recognition and understanding of important roles that fungal biofilms play in contact lens associated fungal keratitis (CLAFK). This review aims to reemphasize the link between fungal biofilms and CLAFK, and deepen our comprehension of its importance in pathogenesis and persistence of this medical device-related infection. Full article

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10 pages, 1936 KiB

Open AccessArticle

Molecular Epidemiology and Antibiotic Resistance Analysis of Non-Typeable Haemophilus influenzae (NTHi) in Guangzhou: A Representative City of Southern China

by Shuxian Wen, Ying Mai, Xu Chen, Kun Xiao, Yongping Lin, Zhenbo Xu and Ling Yang

Antibiotics 2023, 12(4), 656; https://doi.org/10.3390/antibiotics12040656 - 28 Mar 2023

Cited by 4 | Viewed by 2080

Abstract

This study aimed to investigate the molecular epidemiology and antibiotic resistance of Haemophilus influenzae in Guangzhou, China. A total of 80 H. influenzae isolates were collected from the First Affiliated Hospital of Guangzhou Medical University from January 2020 to April 2021. Species identification, antimicrobial susceptibility, molecular capsular typing, multilocus sequence typing and the clinical characteristics analysis of patients were performed. For all recruited isolates, the majority of H. influenzae strains from patients with respiratory symptoms were found to be non-typeable H. influenzae (NTHi). The isolates were relative susceptible to third- and fourth-generation cephalosporins, quinolones and chloramphenicol, despite having a high ampicillin resistance rate (>70%). The genotyping results reveal a total of 36 sequence types (STs), with ST12 being the most prevalent ST. Remarkably, the 36 STs identified from 80 NTHi isolates within a short period of 15 months and in a single medical setting have revealed a high genetic diversity in NTHi isolates. In comparison, it is noteworthy that the most prevalent STs found in the present study have rarely been found to overlap with those from previous studies. This is the first study on the molecular epidemiology of NTHi isolates in Guangzhou, a city that is representative of southern China. Full article

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4 pages, 199 KiB

Open AccessEditorial

New Insights in Molecular Mechanisms in Antimicrobial Resistance and Strategies in Anti-Biofilms

by Junyan Liu, Zhenbo Xu, Yulong Tan, Ren-You Gan, Guanggang Qu and Dingqiang Chen

Antibiotics 2023, 12(4), 634; https://doi.org/10.3390/antibiotics12040634 - 23 Mar 2023

Cited by 1 | Viewed by 1938

Abstract

This topical collection, entitled “Antimicrobial resistance and anti-biofilms”, was first launched in the journal Antibiotics in November of 2020 [...] Full article

28 pages, 7716 KiB

Open AccessArticle

Effect of Extracts, Fractions, and Isolated Molecules of Casearia sylvestris to Control Streptococcus mutans Cariogenic Biofilm

by Sabrina M. Ribeiro, Paula C. P. Bueno, Alberto José Cavalheiro and Marlise I. Klein

Antibiotics 2023, 12(2), 329; https://doi.org/10.3390/antibiotics12020329 - 4 Feb 2023

Cited by 4 | Viewed by 1798

Abstract

The effects of extracts, fractions, and molecules of Casearia sylvestris to control the cariogenic biofilm of Streptococcus mutans were evaluated. First, the antimicrobial and antibiofilm (initial and pre-formed biofilms) in prolonged exposure (24 h) models were investigated. Second, formulations (with and without fluoride) were assessed for topical effects (brief exposure) on biofilms. Third, selected treatments were evaluated via bacterium growth inhibition curves associated with gene expression and scanning electron microscopy. In initial biofilms, the ethyl acetate (AcOEt) and ethanolic (EtOH) fractions from Brasília (BRA/DF; 250 µg/mL) and Presidente Venceslau/SP (Water/EtOH 60:40 and Water/EtOH 40:60; 500 µg/mL) reduced ≥6-logs vs. vehicle. Only the molecule Caseargrewiin F (CsF; 125 µg/mL) reduced the viable cell count of pre-formed biofilms (5 logs vs. vehicle). For topical effects, no formulation affected biofilm components. For the growth inhibition assay, CsF yielded a constant recovery of surviving cells (≅3.5 logs) until 24 h (i.e., bacteriostatic), and AcOEt_BRA/DF caused progressive cell death, without cells at 24 h (i.e., bactericidal). CsF and AcOEt_BRA/DF damaged S. mutans cells and influenced the expression of virulence genes. Thus, an effect against biofilms occurred after prolonged exposure due to the bacteriostatic and/or bactericidal capacity of a fraction and a molecule from C. sylvestris. Full article

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2022

Jump to: 2023, 2021

21 pages, 2419 KiB

Open AccessReview

A Review of Biofilm Formation of Staphylococcus aureus and Its Regulation Mechanism

by Qi Peng, Xiaohua Tang, Wanyang Dong, Ning Sun and Wenchang Yuan

Antibiotics 2023, 12(1), 12; https://doi.org/10.3390/antibiotics12010012 - 22 Dec 2022

Cited by 69 | Viewed by 14097

Abstract

Bacteria can form biofilms in natural and clinical environments on both biotic and abiotic surfaces. The bacterial aggregates embedded in biofilms are formed by their own produced extracellular matrix. Staphylococcus aureus (S. aureus) is one of the most common pathogens of biofilm infections. The formation of biofilm can protect bacteria from being attacked by the host immune system and antibiotics and thus bacteria can be persistent against external challenges. Therefore, clinical treatments for biofilm infections are currently encountering difficulty. To address this critical challenge, a new and effective treatment method needs to be developed. A comprehensive understanding of bacterial biofilm formation and regulation mechanisms may provide meaningful insights against antibiotic resistance due to bacterial biofilms. In this review, we discuss an overview of S. aureus biofilms including the formation process, structural and functional properties of biofilm matrix, and the mechanism regulating biofilm formation. Full article

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18 pages, 2188 KiB

Open AccessArticle

Valorization of Invasive Plant Extracts against the Bispecies Biofilm Staphylococcus aureus–Candida albicans by a Bioguided Molecular Networking Screening

by Guillaume Hamion, Willy Aucher, Charles Tardif, Julie Miranda, Caroline Rouger, Christine Imbert and Marion Girardot

Antibiotics 2022, 11(11), 1595; https://doi.org/10.3390/antibiotics11111595 - 11 Nov 2022

Cited by 3 | Viewed by 2450

Abstract

Invasive plants efficiently colonize non-native territories, suggesting a great production of bioactive metabolites which could be effective antibiofilm weapons. Our study aimed to look for original molecules able to inhibit bispecies biofilm formed by S. aureus and C. albicans. Extracts from five invasive macrophytes (Ludwigia peploides, Ludwigia grandiflora, Myriophyllum aquaticum, Lagarosiphon major and Egeria densa) were prepared and tested in vitro against 24 h old bispecies biofilms using a crystal violet staining (CVS) assay. The activities of the extracts reducing the biofilm total biomass by 50% or more were comparatively analyzed against each microbial species forming the biofilm by flow cytometry (FCM) and scanning electron microscopy. Extracts active against both species were fractionated. Obtained fractions were analyzed by UHPLC-MS/MS and evaluated by the CVS assay. Chemical and biological data were combined into a bioactivity-based molecular networking (BBMN) to identify active compounds. The aerial stem extract of L. grandiflora showed the highest antibiofilm activity (>50% inhibition at 50 µg∙mL⁻¹). The biological, chemical and BBMN investigations of its fractions highlighted nine ions correlated with the antibiofilm activity. The most correlated compound, identified as betulinic acid (BA), inhibited bispecies biofilms regardless of the three tested couples of strains (ATCC strains: >40% inhibition, clinical isolates: ≈27% inhibition), confirming its antibiofilm interest. Full article

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13 pages, 3467 KiB

Open AccessArticle

Antibiofilm Effect of Cinnamaldehyde-Chitosan Nanoparticles against the Biofilm of Staphylococcus aureus

by Jiaman Xu, Quan Lin, Maokun Sheng, Ting Ding, Bing Li, Yan Gao and Yulong Tan

Antibiotics 2022, 11(10), 1403; https://doi.org/10.3390/antibiotics11101403 - 13 Oct 2022

Cited by 20 | Viewed by 2715

Abstract

Food contamination caused by food-spoilage bacteria and pathogenic bacteria seriously affects public health. Staphylococcus aureus is a typical foodborne pathogen which easily forms biofilm. Once biofilm is formed, it is difficult to remove. The use of nanotechnology for antibiofilm purposes is becoming more widespread because of its ability to increase the bioavailability and biosorption of many drugs. In this work, chitosan nanoparticles (CSNPs) were prepared by the ion–gel method with polyanionic sodium triphosphate (TPP). Cinnamaldehyde (CA) was loaded onto the CSNPs. The particle size, potential, morphology, encapsulation efficiency and in vitro release behavior of cinnamaldehyde–chitosan nanoparticles (CSNP-CAs) were studied, and the activity of CA against S. aureus biofilms was evaluated. The biofilm structure on the silicone surface was investigated by scanning electron microscopy (SEM). Confocal laser scanning microscopy (CLSM) was used to detect live/dead organisms within biofilms. The results showed that CSNP-CAs were dispersed in a circle with an average diameter of 298.1 nm and a zeta potential of +38.73 mV. The encapsulation efficiency of cinnamaldehyde (CA) reached 39.7%. In vitro release studies have shown that CA can be continuously released from the CSNPs. Compared with free drugs, CSNP-CAs have a higher efficacy in removing S. aureus biofilm, and the eradication rate of biofilm can reach 61%. The antibiofilm effects of CSNP-CAs are determined by their antibacterial properties. The minimum inhibitory concentration (MIC) of CA is 1.25 mg/mL; at this concentration the bacterial cell wall ruptures and the permeability of the cell membrane increases, which leads to leakage of the contents. At the same time, we verified that the MIC of CSNP-CAs is 2.5 mg/mL (drug concentration). The synergy between CA and CSNPs demonstrates the combinatorial application of a composite as an efficient novel therapeutic agent against antibiofilm. We can apply it in food preservation and other contexts, providing new ideas for food preservation. Full article

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8 pages, 391 KiB

Open AccessCase Report

Antimicrobial Treatment on a Catheter-Related Bloodstream Infection (CRBSI) Case Due to Transition of a Multi-Drug-Resistant Ralstonia mannitolilytica from Commensal to Pathogen during Hospitalization

by Junyan Liu, Brian M. Peters, Ling Yang, Hui Yu, Donghua Feng, Dingqiang Chen and Zhenbo Xu

Antibiotics 2022, 11(10), 1376; https://doi.org/10.3390/antibiotics11101376 - 8 Oct 2022

Cited by 3 | Viewed by 2229

Abstract

Despite its commonly overlooked role as a commensal, Ralstonia mannitolilytica becomes an emerging global opportunistic human pathogen and a causative agent of various infections and diseases. In respiratory illnesses, including cystic fibrosis and chronic obstructive pulmonary disease (COPD), R. mannitolilytica is also identified presumably as colonizer. In this study, one distinctive clone of R. mannitolilytica was firstly identified as colonizer for the first 20 days during hospitalization of a patient. It was then identified as a causative agent for catheter-related bloodstream infection with negative identification after effective treatment, verifying its transition from commensal to pathogen. In conclusion, we provide convincing evidence that during hospitalization of a patient, R. mannitolilytica transitioned from commensal to pathogen in the respiratory tract leading to catheter-related bloodstream infection (CRBSI). Full article

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15 pages, 1912 KiB

Open AccessArticle

Eradication of Staphylococcus aureus Biofilm Infection by Persister Drug Combination

by Rebecca Yee, Yuting Yuan, Andreina Tarff, Cory Brayton, Naina Gour, Jie Feng and Ying Zhang

Antibiotics 2022, 11(10), 1278; https://doi.org/10.3390/antibiotics11101278 - 20 Sep 2022

Cited by 13 | Viewed by 3413

Abstract

Staphylococcus aureus can cause a variety of infections, including persistent biofilm infections, which are difficult to eradicate with current antibiotic treatments. Here, we demonstrate that combining drugs that have robust anti-persister activity, such as clinafloxacin or oritavancin, in combination with drugs that have high activity against growing bacteria, such as vancomycin or meropenem, could completely eradicate S. aureus biofilm bacteria in vitro. In contrast, single or two drugs, including the current treatment doxycycline plus rifampin for persistent S. aureus infection, failed to kill all biofilm bacteria in vitro. In a chronic persistent skin infection mouse model, we showed that the drug combination clinafloxacin + meropenem + daptomycin which killed all biofilm bacteria in vitro completely eradicated S. aureus biofilm infection in mice while the current treatments failed to do so. The complete eradication of biofilm bacteria is attributed to the unique high anti-persister activity of clinafloxacin, which could not be replaced by other fluoroquinolones including moxifloxacin, levofloxacin, or ciprofloxacin. We also compared our persister drug combination with the current approaches for treating persistent infections, including gentamicin + fructose and ADEP4 + rifampin in the S. aureus biofilm infection mouse model, and found neither treatment could eradicate the biofilm infection. Our study demonstrates an important treatment principle, the Yin–Yang model, for persistent infections by targeting both growing and non-growing heterogeneous bacterial populations, utilizing persister drugs for the more effective eradication of persistent and biofilm infections. Our findings have implications for the improved treatment of other persistent and biofilm infections in general. Full article

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18 pages, 1603 KiB

Open AccessArticle

Evaluation of Catechin Synergistic and Antibacterial Efficacy on Biofilm Formation and acrA Gene Expression of Uropathogenic E. coli Clinical Isolates

by Najwan Jubair, Mogana R., Ayesha Fatima, Yasir K. Mahdi and Nor Hayati Abdullah

Antibiotics 2022, 11(9), 1223; https://doi.org/10.3390/antibiotics11091223 - 9 Sep 2022

Cited by 5 | Viewed by 3070

Abstract

Uropathogenic Escherichia coli has a propensity to build biofilms to resist host defense and antimicrobials. Recurrent urinary tract infection (UTI) caused by multidrug-resistant, biofilm-forming E. coli is a significant public health problem. Consequently, searching for alternative medications has become essential. This study was undertaken to investigate the antibacterial, synergistic, and antibiofilm activities of catechin isolated from Canarium patentinervium Miq. against three E. coli ATCC reference strains (ATCC 25922, ATCC 8739, and ATCC 43895) and fifteen clinical isolates collected from UTI patients in Baghdad, Iraq. In addition, the expression of the biofilm-related gene, acrA, was evaluated with and without catechin treatment. Molecular docking was performed to evaluate the binding mode between catechin and the target protein using Autodock Vina 1.2.0 software. Catechin demonstrated significant bactericidal activity with a minimum inhibitory concentration (MIC) range of 1–2 mg/mL and a minimum bactericidal concentration (MBC) range of 2–4 mg/mL and strong synergy when combined with tetracycline at the MBC value. In addition, catechin substantially reduced E. coli biofilm by downregulating the acrA gene with a reduction percent ≥ 60%. In silico analysis revealed that catechin bound with high affinity (∆G = −8.2 kcal/mol) to AcrB protein (PDB-ID: 5ENT), one of the key AcrAB-TolC efflux pump proteins suggesting that catechin might inhibit the acrA gene indirectly by docking at the active site of AcrB protein. Full article

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13 pages, 2825 KiB

Open AccessArticle

Occurrence of Serratia marcescens Carrying bla_IMP-26 and mcr-9 in Southern China: New Insights in the Evolution of Megaplasmid IMP-26

by Yuxia Zhong, Wanting Liu, Peibo Yuan, Ling Yang, Zhenbo Xu and Dingqiang Chen

Antibiotics 2022, 11(7), 869; https://doi.org/10.3390/antibiotics11070869 - 28 Jun 2022

Cited by 5 | Viewed by 2949

Abstract

The spread of multidrug-resistant enterobacteria strains has posed a significant concern in public health, especially when the strain harbors metallo-beta-lactamase (MBL)-encoding and mobilized colistin resistance (mcr) genes as such genetic components potentially mediate multidrug resistance. Here we report an IncHI2/2A plasmid carrying bla_IMP-26 and mcr-9 in multidrug-resistant Serratia marcescens human isolates YL4. Antimicrobial susceptibility testing was performed by the broth microdilution method. According to the results, S. marcescens YL4 was resistant to several antimicrobials, including β-lactams, fluorquinolones, sulfanilamide, glycylcycline, and aminoglycosides, except for amikacin. To investigate the plasmid further, we conducted whole-genome sequencing and sequence analysis. As shown, S. marcescens YL4 possessed a circular chromosome with 5,171,477 bp length and two plasmids, pYL4.1 (321,744 bp) and pYL4.2 (46,771 bp). Importantly, sharing high similarity with plasmids pZHZJ1 and pIMP-26, pYL4.1 has an IncHI2/2A backbone holding a variable region containing bla_IMP-26, mcr-9, and two copies of bla_TEM-1B. After comprehensively comparing relevant plasmids, we proposed an evolutionary pathway originating from ancestor pZHZJ1. Then, via an acquisition of the mcr-9 element and a few recombination events, this plasmid eventually evolved into pYL4.1 and pIMP-26 through two different pathways. In addition, the phage-like plasmid pYL4.2 also carried a bla_TEM-1B gene. Remarkably, this study first identified a multidrug-resistant S. marcescens strain co-harboring bla_IMP-26 and mcr-9 on a megaplasmid pYL4.1 and also included a proposed evolutionary pathway of epidemic megaplasmids carrying bla_IMP-26. Full article

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8 pages, 1300 KiB

Open AccessArticle

The 30-Day Economic Burden of Newly Diagnosed Complicated Urinary Tract Infections in Medicare Fee-for-Service Patients Who Resided in the Community

by Thomas P. Lodise, Michael Nowak and Mauricio Rodriguez

Antibiotics 2022, 11(5), 578; https://doi.org/10.3390/antibiotics11050578 - 26 Apr 2022

Cited by 2 | Viewed by 3576

Abstract

Introduction: Scant data are available on the 30-day financial burden associated with incident complicated urinary tract infections (cUTIs) in a cohort of predominately elderly patients. This study sought to examine total and cUTI-related 30-day Medicare spending (MS), a proxy for healthcare costs, among Medicare fee-for-service (FFS) beneficiaries who resided in the community with newly diagnosed cUTIs. Methods: A retrospective multicenter cohort study of adult beneficiaries in the Medicare FFS database with a cUTI between 2017 and 2018 was performed. Patients were included if they were enrolled in Medicare FFS and Medicare Part D from 2016 to 2019, had a cUTI first diagnosis in 2017–2018, no evidence of any UTI diagnoses in 2016, and residence in the community between 2016 and 2018. Results: During the study period, 723,324 cases occurred in Medicare beneficiaries who met the study criteria. Overall and cUTI-related 30-day MS were $7.6 and $4.5 billion, respectively. The average overall and cUTI-related 30-day MS per beneficiary were $10,527 and $6181, respectively. The major driver of cUTI-related 30-day MS was acute care hospitalizations ($3.2 billion) and the average overall and cUTI-related 30-day MS per hospitalizations were $16,431 and $15,438, respectively. Conclusion: Overall 30-day MS for Medicare FSS patients who resided in the community with incident cUTIs was substantial, with cUTI-related MS accounting for 59%. As the major driver of cUTI-related 30-day MS was acute care hospitalizations, healthcare systems should develop well-defined criteria for hospital admissions that aim to avert hospitalizations in clinically stable patients and expedite the transition of patients to the outpatient setting to complete their care. Full article

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2021

Jump to: 2023, 2022

7 pages, 1230 KiB

Open AccessArticle

NDM Production as a Dominant Feature in Carbapenem-Resistant Enterobacteriaceae Isolates from a Tertiary Care Hospital

by Fakhur Uddin, Syed Hadi Imam, Saeed Khan, Taseer Ahmed Khan, Zulfiqar Ahmed, Muhammad Sohail, Ashraf Y. Elnaggar, Ahmed M. Fallatah and Zeinhom M. El-Bahy

Antibiotics 2022, 11(1), 48; https://doi.org/10.3390/antibiotics11010048 - 31 Dec 2021

Cited by 14 | Viewed by 2601

Abstract

The worldwide spread and increasing prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is of utmost concern and a problem for public health. This resistance is mainly conferred by carbapenemase production. Such strains are a potential source of outbreaks in healthcare settings and are associated with high rates of morbidity and mortality. In this study, we aimed to determine the dominance of NDM-producing Enterobacteriaceae at a teaching hospital in Karachi. A total of 238 Enterobacteriaceae isolates were collected from patients admitted to Jinnah Postgraduate Medical Centre (Unit 4) in Karachi, Pakistan, a tertiary care hospital. Phenotypic and genotypic methods were used for detection of metallo-β-lactamase. Out of 238 isolates, 52 (21.8%) were CRE and 50 isolates were carbapenemase producers, as determined by the CARBA NP test; two isolates were found negative for carbapenemase production by CARB NP and PCR. Four carbapenemase-producing isolates phenotypically appeared negative for metallo-β-lactamase (MBL). Of the 52 CRE isolates, 46 (88.46%) were bla_NDM positive. Most of the NDM producers were Klebsiella pneumoniae, followed by Enterobacter cloacae and Escherichia coli. In all the NDM-positive isolates, the bla_NDM gene was found on plasmid. These isolates were found negative for the VIM and IPM MBLs. All the CRE and carbapenem-sensitive isolates were sensitive to colistin. It is concluded that the NDM is the main resistance mechanism against carbapenems and is dominant in this region. Full article

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Published Papers (13 papers)

2023

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2022

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2021

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