Screening and Characterization of Multidrug-Resistant Gram-Negative Bacteria from a Remote African Area, São Tomé and Príncipe

ABSTRACT The occurrence of resistance to last-resort antibiotics was evaluated among Enterobacteriaceae isolates recovered from hospitalized children in a remote African archipelago, São Tomé and Príncipe, where there is limited access to those antibiotics. Fifty patients were screened for colonization by carbapenem-, pan-aminoglycoside-, or polymyxin-resistant Enterobacteriaceae. A total of 36 isolates (including 30 Escherichia coli and 4 Klebsiella pneumoniae) were recovered from 23 patients, including 26 isolates harboring the blaOXA-181 carbapenemase gene, a single isolate harboring the 16S rRNA methylase gene rmtB encoding pan-resistance to aminoglycosides, and 8 isolates coharboring both genes. A single isolate possessed the plasmid-borne colistin resistance gene mcr-1. A high clonal relationship was found for OXA-181-producing E. coli (4 clones), and conversely, three of the four OXA-181-producing K. pneumoniae isolates were clonally unrelated. This study overall showed a high prevalence of resistance to last-resort antibiotics in this country, where no epidemiological data were previously available.

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Characterization of Multidrug-Resistant Escherichia coli Isolates from Animals Presenting at a University Veterinary Hospital

Applied and Environmental Microbiology ◽

10.1128/aem.00599-11 ◽

2011 ◽

Vol 77 (20) ◽

pp. 7104-7112 ◽

Cited By ~ 59

Author(s):

Maria Karczmarczyk ◽

Yvonne Abbott ◽

Ciara Walsh ◽

Nola Leonard ◽

Séamus Fanning

Keyword(s):

Escherichia Coli ◽

Molecular Mechanisms ◽

Gene Array ◽

Multidrug Resistant ◽

Genetic Determinants ◽

Gene Encoding ◽

Content Type ◽

E Coli ◽

Class 1

ABSTRACTIn this study, we examined molecular mechanisms associated with multidrug resistance (MDR) in a collection ofEscherichia coliisolates recovered from hospitalized animals in Ireland. PCR and DNA sequencing were used to identify genes associated with resistance. Class 1 integrons were prevalent (94.6%) and contained gene cassettes recognized previously and implicated mainly in resistance to aminoglycosides, β-lactams, and trimethoprim (aadA1,dfrA1-aadA1,dfrA17-aadA5,dfrA12-orfF-aadA2,blaOXA-30-aadA1,aacC1-orf1-orf2-aadA1,dfr7). Class 2 integrons (13.5%) contained thedfrA1-sat1-aadA1gene array. The most frequently occurring phenotypes included resistance to ampicillin (97.3%), chloramphenicol (75.4%), florfenicol (40.5%), gentamicin (54%), neomycin (43.2%), streptomycin (97.3%), sulfonamide (98.6%), and tetracycline (100%). The associated resistance determinants detected includedblaTEM,cat,floR,aadB,aphA1,strA-strB,sul2, andtet(B), respectively. TheblaCTX-M-2gene, encoding an extended-spectrum β-lactamase (ESβL), andblaCMY-2, encoding an AmpC-like enzyme, were identified in 8 and 18 isolates, respectively. The mobility of the resistance genes was demonstrated using conjugation assays with a representative selection of isolates. High-molecular-weight plasmids were found to be responsible for resistance to multiple antimicrobial compounds. The study demonstrated that animal-associated commensalE. coliisolates possess a diverse repertoire of transferable genetic determinants. Emergence of ESβLs and AmpC-like enzymes is particularly significant. To our knowledge, theblaCTX-M-2gene has not previously been reported in Ireland.

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Analysis of the Resistome of a Multidrug-Resistant NDM-1-Producing Escherichia coli Strain by High-Throughput Genome Sequencing

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00165-11 ◽

2011 ◽

Vol 55 (9) ◽

pp. 4224-4229 ◽

Cited By ~ 91

Author(s):

Laurent Poirel ◽

Rémy A. Bonnin ◽

Patrice Nordmann

Keyword(s):

Escherichia Coli ◽

Genome Sequencing ◽

High Throughput ◽

Multidrug Resistant ◽

Replicase Gene ◽

Content Type ◽

E Coli ◽

Resistance Determinants ◽

16S Rna ◽

Carbapenemase Gene

ABSTRACTThe resistome of the multidrug-resistantEscherichia colistrain 271 carrying the plasmid-mediatedblaNDM-1carbapenemase gene was analyzed by high-throughput genome sequencing. The p271A plasmid carrying theblaNDM-1gene was 35.9 kb in size and possessed an IncN-type backbone that harbored a novel replicase gene. Acquisition of theblaNDM-1gene on plasmid p271A had been likely the result of a cointegration event involving the transposase of Tn5403. The expression ofblaNDM-1was associated with the insertion sequence ISAba125likely originating fromAcinetobacter baumannii. E. coli271 accumulated multiple resistance determinants, including five β-lactamase genes (comprising the extended-spectrum β-lactamase CTX-M-15), two 16S RNA methylase ArmA- and RmtB-encoding genes, and theqepAgene encoding an efflux pump involved in resistance to fluoroquinolones. These resistance genes were located on three additional plasmids, of 160 kb (IncA/C), 130 kb (IncF), and 110 kb (IncI1). In addition, several chromosomally encoded resistance determinants were identified, such as topoisomerase mutations, porin modifications and truncations, and the intrinsicampCgene ofE. colithat was weakly expressed. The multidrug resistance pattern observed forE. coli271 was therefore the result of combined chromosome- and plasmid-encoded mechanisms.

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Selective Inhibition ofNeisseria gonorrhoeaeby a Dithiazoline in Mixed Infections withLactobacillus gasseri

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00826-18 ◽

2018 ◽

Vol 62 (12) ◽

Cited By ~ 3

Author(s):

Jonathan D. Lenz ◽

Kristina A. Shirk ◽

Adrienne Jolicoeur ◽

Joseph P. Dillard

Keyword(s):

Selective Inhibition ◽

Multidrug Resistant ◽

Selective Toxicity ◽

Content Type ◽

E Coli ◽

Cell Wall Assembly ◽

Specific Stationary Phase ◽

Wall Assembly ◽

Dual Drug

ABSTRACTThe Gram-negative human pathogenNeisseria gonorrhoeaehas progressively developed resistance to antibiotic monotherapies, and recent failures of dual-drug therapy have heightened concerns that strains resistant to all available antibiotics will begin circulating globally. Targeting bacterial cell wall assembly has historically been effective at treating infections withN. gonorrhoeae, but as the effectiveness of β-lactams (including cephalosporins) is challenged by increasing resistance, research has expanded into compounds that target the numerous other enzymes with roles in peptidoglycan metabolism. One example is the dithiazoline compound JNJ-853346 (DTZ), which inhibits the activity of anEscherichia coliserine proteasel,d-carboxypeptidase (LdcA). Recently, the characterization of an LdcA homolog inN. gonorrhoeaerevealed localization and activity differences from the characterizedE. coliLdcA, prompting us to explore the effectiveness of DTZ againstN. gonorrhoeae. We found that DTZ is effective at inhibitingN. gonorrhoeaein all growth phases, unlike the specific stationary-phase inhibition seen inE. coli. Surprisingly, DTZ does not inhibit gonococcal LdcA enzyme activity, and DTZ sensitivity is not significantly decreased inldcAmutants. While effective against numerousN. gonorrhoeaestrains, including recent multidrug-resistant isolates, DTZ is much less effective at inhibiting growth of the commensal speciesLactobacillus gasseri. DTZ treatment during coinfections of epithelial cells resulted in significant lowering of gonococcal burden and interleukin-8 secretion without significantly impacting recovery of viableL. gasseri. This selective toxicity presents a possible pathway for the use of DTZ as an effective antigonococcal agent at concentrations that do not impact vaginal commensals.

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Molecular Characterization of Escherichia coli Isolates Carrying mcr-1, fosA3, and Extended-Spectrum-β-Lactamase Genes from Food Samples in China

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00064-17 ◽

2017 ◽

Vol 61 (6) ◽

Cited By ~ 10

Author(s):

Xiaobo Liu ◽

Ruichao Li ◽

Zhiwei Zheng ◽

Kaichao Chen ◽

Miaomiao Xie ◽

...

Keyword(s):

Public Health ◽

Escherichia Coli ◽

Molecular Characterization ◽

Food Products ◽

Multidrug Resistant ◽

Food Samples ◽

Content Type ◽

E Coli ◽

Extended Spectrum

ABSTRACT This study surveyed the prevalence of mcr-1 in extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli strains of food origin in China and identified strains that carried mcr-1, fosA3, and ESBL genes, which were carried in various plasmids. The mcr-1 and ESBL genes could be cotransferred by one or more types of plasmids. The presence of these multidrug-resistant E. coli strains in food products might pose a huge threat to public health.

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Houseflies (Musca domestica) as Vectors for Extended-Spectrum β-Lactamase-Producing Escherichia coli on Spanish Broiler Farms

Applied and Environmental Microbiology ◽

10.1128/aem.04252-14 ◽

2015 ◽

Vol 81 (11) ◽

pp. 3604-3611 ◽

Cited By ~ 27

Author(s):

Marc Solà-Ginés ◽

Juan José González-López ◽

Karla Cameron-Veas ◽

Nuria Piedra-Carrasco ◽

Marta Cerdà-Cuéllar ◽

...

Keyword(s):

Escherichia Coli ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Ecological Niches ◽

Potential Contribution ◽

Content Type ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Extended Spectrum

ABSTRACTFlies may act as potential vectors for the spread of resistant bacteria to different environments. This study was intended to evaluate the presence ofEscherichia colistrains resistant to cephalosporins in flies captured in the areas surrounding five broiler farms. Phenotypic and molecular characterization of the resistant population was performed by different methods: MIC determination, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and phylotyping. The presence of extended-spectrum beta-lactamase (ESBL) genes, their plasmid location, and the mobile genetic elements involved in their mobilization were studied. Additionally, the presence of 35 genes associated with virulence was evaluated. Out of 682 flies captured, 42 yielded ESBL-producingE. coli. Of these isolates, 23 containedblaCTX-M-1, 18 containedblaCTX-M-14, and 1 containedblaCTX-M-9. ESBL genes were associated mainly with the presence of the IncI1 and IncFIB replicons. Additionally, all the strains were multiresistant, and five of them also harboredqnrS. Identical PFGE profiles were found forE. coliisolates obtained from flies at different sampling times, indicating a persistence of the same clones in the farm environment over months. According to their virulence genes, 81% of the isolates were considered avian-pathogenicE. coli(APEC) and 29% were considered extraintestinal pathogenicE. coli(ExPEC). The entrance of flies into broiler houses constitutes a considerable risk for colonization of broilers with multidrug-resistantE. coli. ESBLs in flies reflect the contamination status of the farm environment. Additionally, this study demonstrates the potential contribution of flies to the dissemination of virulence and resistance genes into different ecological niches.

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Prevalence, Risk Factors, and Characterization of Multidrug Resistant and ESBL/AmpC Producing Escherichia coli in Healthy Horses in Quebec, Canada, in 2015–2016

Animals ◽

10.3390/ani10030523 ◽

2020 ◽

Vol 10 (3) ◽

pp. 523 ◽

Cited By ~ 1

Author(s):

Maud de Lagarde ◽

John M. Fairbrother ◽

Julie Arsenault

Keyword(s):

Risk Factors ◽

Healthy Adult ◽

Epidemiological Data ◽

Multidrug Resistant ◽

Facility Management ◽

E Coli ◽

Equine Medicine ◽

Potential Risk Factors ◽

Amoxicillin Clavulanic Acid

Although antimicrobial resistance is an increasing threat in equine medicine, molecular and epidemiological data remain limited in North America. We assessed the prevalence of, and risk factors for, shedding multidrug-resistant (MDR) and extended-spectrum β-lactamase (ESBL) and/or AmpC β-lactamase-producing E. coli in healthy horses in Quebec, Canada. We collected fecal samples in 225 healthy adult horses from 32 premises. A questionnaire on facility management and horse medical history was completed for each horse. Indicator (without enrichment) and specific (following enrichment with ceftriaxone) E. coli were isolated and tested for antimicrobial susceptibility. The presence of ESBL/AmpC genes was determined by PCR. The prevalence of isolates that were non-susceptible to antimicrobials and to antimicrobial classes were estimated at the horse and the premises level. Multivariable logistic regression was used to assess potential risk factors for MDR and ESBL/AmpC isolates. The shedding of MDR E. coli was detected in 46.3% of horses. Non-susceptibility was most commonly observed to ampicillin, amoxicillin/clavulanic acid or streptomycin. ESBL/AmpC producing isolates were detected in 7.3% of horses. The most commonly identified ESBL/AmpC gene was blaCTX-M-1, although we also identified blaCMY-2. The number of staff and equestrian event participation were identified as risk factors for shedding MDR isolates. The prevalence of healthy horses harboring MDR or ESBL/AmpC genes isolates in their intestinal microbiota is noteworthy. We identified risk factors which could help to develop guidelines to preclude their spread.

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Novel 5-Nitrofuran-Activating Reductase in Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00868-19 ◽

2019 ◽

Vol 63 (11) ◽

Cited By ~ 1

Author(s):

Vuong Van Hung Le ◽

Ieuan G. Davies ◽

Christina D. Moon ◽

David Wheeler ◽

Patrick J. Biggs ◽

...

Keyword(s):

Escherichia Coli ◽

Antibacterial Activity ◽

Epidemiological Data ◽

Multidrug Resistant ◽

Antimicrobial Drugs ◽

Antibiotic Resistant ◽

Content Type ◽

E Coli ◽

History Of ◽

Low Prevalence

ABSTRACT The global spread of multidrug-resistant enterobacteria warrants new strategies to combat these pathogens. One possible approach is the reconsideration of “old” antimicrobials, which remain effective after decades of use. Synthetic 5-nitrofurans such as furazolidone, nitrofurantoin, and nitrofurazone are such a class of antimicrobial drugs. Recent epidemiological data showed a very low prevalence of resistance to this antimicrobial class among clinical Escherichia coli isolates in various parts of the world, forecasting the increasing importance of its uses to battle antibiotic-resistant enterobacteria. However, although they have had a long history of clinical use, a detailed understanding of the 5-nitrofurans’ mechanisms of action remains limited. Nitrofurans are known as prodrugs that are activated in E. coli by reduction catalyzed by two redundant nitroreductases, NfsA and NfsB. Furazolidone, nevertheless, retains relatively significant antibacterial activity in the nitroreductase-deficient ΔnfsA ΔnfsB E. coli strain, indicating the presence of additional activating enzymes and/or antibacterial activity of the unreduced form. Using genome sequencing, genetic, biochemical, and bioinformatic approaches, we discovered a novel 5-nitrofuran-activating enzyme, AhpF, in E. coli. The discovery of a new nitrofuran-reducing enzyme opens new avenues for overcoming 5-nitrofuran resistance, such as designing nitrofuran analogues with higher affinity for AhpF or screening for adjuvants that enhance AhpF expression.

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Presence of β-Lactamase-producing Enterobacterales and Salmonella Isolates in Marine Mammals

International Journal of Molecular Sciences ◽

10.3390/ijms22115905 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5905

Author(s):

Olivia M. Grünzweil ◽

Lauren Palmer ◽

Adriana Cabal ◽

Michael P. Szostak ◽

Werner Ruppitsch ◽

...

Keyword(s):

Escherichia Coli ◽

Marine Mammals ◽

Virulence Genes ◽

Multidrug Resistant ◽

Healthcare Sector ◽

Whole Genome ◽

E Coli ◽

High Prevalence ◽

Lactamase Gene ◽

Sequence Types

Marine mammals have been described as sentinels of the health of marine ecosystems. Therefore, the aim of this study was to investigate (i) the presence of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacterales, which comprise several bacterial families important to the healthcare sector, as well as (ii) the presence of Salmonella in these coastal animals. The antimicrobial resistance pheno- and genotypes, as well as biocide susceptibility of Enterobacterales isolated from stranded marine mammals, were determined prior to their rehabilitation. All E. coli isolates (n = 27) were screened for virulence genes via DNA-based microarray, and twelve selected E. coli isolates were analyzed by whole-genome sequencing. Seventy-one percent of the Enterobacterales isolates exhibited a multidrug-resistant (MDR) pheno- and genotype. The gene blaCMY (n = 51) was the predominant β-lactamase gene. In addition, blaTEM-1 (n = 38), blaSHV-33 (n = 8), blaCTX-M-15 (n = 7), blaOXA-1 (n = 7), blaSHV-11 (n = 3), and blaDHA-1 (n = 2) were detected. The most prevalent non-β-lactamase genes were sul2 (n = 38), strA (n = 34), strB (n = 34), and tet(A) (n = 34). Escherichia coli isolates belonging to the pandemic sequence types (STs) ST38, ST167, and ST648 were identified. Among Salmonella isolates (n = 18), S. Havana was the most prevalent serotype. The present study revealed a high prevalence of MDR bacteria and the presence of pandemic high-risk clones, both of which are indicators of anthropogenic antimicrobial pollution, in marine mammals.

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Independent Behavior of Commensal Flora for Carriage of Fluoroquinolone-Resistant Bacteria in Patients at Admission

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00823-10 ◽

2010 ◽

Vol 54 (12) ◽

pp. 5193-5200 ◽

Cited By ~ 22

Author(s):

Victoire de Lastours ◽

Françoise Chau ◽

Florence Tubach ◽

Blandine Pasquet ◽

Etienne Ruppé ◽

...

Keyword(s):

Risk Factors ◽

Bacterial Resistance ◽

Care Facility ◽

Health Care Facility ◽

Epidemiological Data ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

E Coli ◽

Commensal Flora ◽

Resistant Strains

ABSTRACT The important role of commensal flora as a natural reservoir of bacterial resistance is now well established. However, whether the behavior of each commensal flora is similar to that of other floras in terms of rates of carriage and risk factors for bacterial resistance is unknown. During a 6-month period, we prospectively investigated colonization with fluoroquinolone-resistant bacteria in the three main commensal floras from hospitalized patients at admission, targeting Escherichia coli in the fecal flora, coagulase-negative Staphylococcus (CNS) in the nasal flora, and α-hemolytic streptococci in the pharyngeal flora. Resistant strains were detected on quinolone-containing selective agar. Clinical and epidemiological data were collected. A total of 555 patients were included. Carriage rates of resistance were 8.0% in E. coli, 30.3% in CNS for ciprofloxacin, and 27.2% in streptococci for levofloxacin; 56% of the patients carried resistance in at least one flora but only 0.9% simultaneously in all floras, which is no more than random. Risk factors associated with the carriage of fluoroquinolone-resistant strains differed between fecal E. coli (i.e., colonization by multidrug-resistant bacteria) and nasal CNS (i.e., age, coming from a health care facility, and previous antibiotic treatment with a fluoroquinolone) while no risk factors were identified for pharyngeal streptococci. Despite high rates of colonization with fluoroquinolone-resistant bacteria, each commensal flora behaved independently since simultaneous carriage of resistance in the three distinct floras was uncommon, and risk factors differed. Consequences of environmental selective pressures vary in each commensal flora according to its local specificities (clinical trial NCT00520715 [http://clinicaltrials.gov/ct2/show/NCT00520715 ]).

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An Improved Medium for Colistin Susceptibility Testing

Journal of Clinical Microbiology ◽

10.1128/jcm.01950-17 ◽

2018 ◽

Vol 56 (5) ◽

Cited By ~ 10

Author(s):

Konrad Gwozdzinski ◽

Saina Azarderakhsh ◽

Can Imirzalioglu ◽

Linda Falgenhauer ◽

Trinad Chakraborty

Keyword(s):

Susceptibility Testing ◽

Acquired Resistance ◽

Multidrug Resistant ◽

Colistin Resistance ◽

Reliable Determination ◽

Content Type ◽

E Coli ◽

Resistant Species ◽

Mueller Hinton ◽

Serovar Typhimurium

ABSTRACTThe plasmid-located colistin resistance genemcr-1confers low-level resistance to colistin, a last-line antibiotic against multidrug-resistant Gram-negative bacteria. Current CLSI-EUCAST recommendations require the use of a broth microdilution (BMD) method with cation-adjusted Mueller-Hinton (CA-MH) medium for colistin susceptibility testing, but approximately 15% of all MCR-1 producers are classified as sensitive in that broth. Here we report on an improved calcium-enhanced Mueller-Hinton (CE-MH) medium that permits simple and reliable determination ofmcr-1-containingEnterobacteriaceae. Colistin susceptibility testing was performed for 50mcr-1-containingEscherichia coliandKlebsiella pneumoniaeisolates, 7 intrinsically polymyxin-resistant species,K. pneumoniaeandE. coliisolates with acquired resistance to polymyxins due tomgrBandpmrBmutations, respectively, and 32mcr-1-negative, colistin-susceptible isolates ofAcinetobacter baumannii,Citrobacter freundii,Enterobacter cloacae,E. coli,K. pneumoniae, andSalmonella entericaserovar Typhimurium. A comparison of the colistin MICs determined in CA-MH medium and those obtained in CE-MH medium was performed using both the BMD and strip-based susceptibility test formats. We validated the data using an isogenic IncX4 plasmid lackingmcr-1. Use of the CE-MH broth provides clear separation between resistant and susceptible isolates in both BMD and gradient diffusion assays; this is true for bothmcr-1-containingEnterobacteriaceaeisolates and those exhibiting either intrinsic or acquired colistin resistance. CE-MH medium is simple to prepare and overcomes current problems associated with BMD and strip-based colistin susceptibility testing, and use of the medium is easy to implement in routine diagnostic laboratories, even in resource-poor settings.

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