scholarly journals Design and Preclinical Development of a Phage Product for the Treatment of Antibiotic-Resistant Staphylococcus aureus Infections

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 88 ◽  
Author(s):  
Susan Lehman ◽  
Gillian Mearns ◽  
Deborah Rankin ◽  
Robert Cole ◽  
Frenk Smrekar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Phase 1 ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Preclinical Development ◽  
Antibiotic Resistant ◽  
Fixed Composition ◽  
Spontaneous Frequency

Bacteriophages, viruses that only kill specific bacteria, are receiving substantial attention as nontraditional antibacterial agents that may help alleviate the growing antibiotic resistance problem in medicine. We describe the design and preclinical development of AB-SA01, a fixed-composition bacteriophage product intended to treat Staphylococcus aureus infections. AB-SA01 contains three naturally occurring, obligately lytic myoviruses related to Staphylococcus phage K. AB-SA01 component phages have been sequenced and contain no identifiable bacterial virulence or antibiotic resistance genes. In vitro, AB-SA01 killed 94.5% of 401 clinical Staphylococcus aureus isolates, including methicillin-resistant and vancomycin-intermediate ones for a total of 95% of the 205 known multidrug-resistant isolates. The spontaneous frequency of resistance to AB-SA01 was ≤3 × 10−9, and resistance emerging to one component phage could be complemented by the activity of another component phage. In both neutropenic and immunocompetent mouse models of acute pneumonia, AB-SA01 reduced lung S. aureus populations equivalently to vancomycin. Overall, the inherent characteristics of AB-SA01 component phages meet regulatory and generally accepted criteria for human use, and the preclinical data presented here have supported production under good manufacturing practices and phase 1 clinical studies with AB-SA01.

scholarly journals Conjugative delivery of CRISPR-Cas9 for the selective depletion of antibiotic-resistant enterococci

2019 ◽  
Author(s):  
Marinelle Rodrigues ◽  
Sara W. McBride ◽  
Karthik Hullahalli ◽  
Kelli L. Palmer ◽  
Breck A. Duerkop
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Resistance Genes ◽  
Bacterial Infections ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Conjugative Plasmid ◽  
Antibiotic Resistant ◽  
Resistance Determinants

AbstractThe innovation of new therapies to combat multidrug-resistant (MDR) bacteria is being outpaced by the continued rise of MDR bacterial infections. Of particular concern are hospital-acquired infections (HAIs) recalcitrant to antibiotic therapies. The Gram-positive intestinal pathobiontEnterococcus faecalisis associated with HAIs and some strains are MDR. Therefore, novel strategies to controlE. faecalispopulations are needed. We previously characterized anE. faecalisType II CRISPR-Cas system and demonstrated its utility in the sequence-specific removal of antibiotic resistance determinants. Here we present work describing the adaption of this CRISPR-Cas system into a constitutively expressed module encoded on a pheromone-responsive conjugative plasmid that efficiently transfers toE. faecalisfor the selective removal of antibiotic resistance genes. Usingin vitrocompetition assays, we show that these CRISPR-Cas-encoding delivery plasmids, or CRISPR-Cas antimicrobials, can reduce the occurrence of antibiotic resistance in enterococcal populations in a sequence-specific manner. Furthermore, we demonstrate that deployment of CRISPR-Cas antimicrobials in the murine intestine reduces the occurrence of antibiotic-resistantE. faecalisby several orders of magnitude. Finally, we show thatE. faecalisdonor strains harboring CRISPR-Cas antimicrobials are immune to uptake of antibiotic resistance determinantsin vivo. Our results demonstrate that conjugative delivery of CRISPR-Cas antimicrobials may be adaptable for future deployment from probiotic bacteria for exact targeting of defined MDR bacteria or for precision engineering of polymicrobial communities in the mammalian intestine.ImportanceCRISPR-Cas nucleic acid targeting systems hold promise for the amelioration of multidrug-resistant enterococci, yet the utility of such tools in the context of the intestinal environment where enterococci reside is understudied. We describe the development of a CRISPR-Cas antimicrobial, deployed on a conjugative plasmid, for the targeted removal of antibiotic resistance genes from intestinalEnterococcus faecalis. We demonstrate that CRISPR-Cas targeting reduces antibiotic resistance ofE. faecalisby several orders of magnitude in the intestine. Although barriers exist that influence the penetrance of the conjugative CRISPR-Cas antimicrobial among target recipientE. faecaliscells, the removal of antibiotic resistance genes inE. faecalisupon uptake of the CRISPR-Cas antimicrobial is absolute. In addition, cells that obtain the CRISPR-Cas antimicrobial are immunized against the acquisition of new antibiotic resistance genes. This study suggests a potential path toward plasmid based CRISPR-Cas therapies in the intestine.

scholarly journals Conjugative Delivery of CRISPR-Cas9 for the Selective Depletion of Antibiotic-Resistant Enterococci

2019 ◽  
Vol 63 (11) ◽  
Author(s):  
Marinelle Rodrigues ◽  
Sara W. McBride ◽  
Karthik Hullahalli ◽  
Kelli L. Palmer ◽  
Breck A. Duerkop
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Infections ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Conjugative Plasmid ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Resistance Determinants

ABSTRACT The innovation of new therapies to combat multidrug-resistant (MDR) bacteria is being outpaced by the continued rise of MDR bacterial infections. Of particular concern are hospital-acquired infections (HAIs) that are recalcitrant to antibiotic therapies. The Gram-positive intestinal pathobiont Enterococcus faecalis is associated with HAIs, and some strains are MDR. Therefore, novel strategies to control E. faecalis populations are needed. We previously characterized an E. faecalis type II CRISPR-Cas system and demonstrated its utility in the sequence-specific removal of antibiotic resistance determinants. Here, we present work describing the adaption of this CRISPR-Cas system into a constitutively expressed module encoded on a pheromone-responsive conjugative plasmid that efficiently transfers to E. faecalis for the selective removal of antibiotic resistance genes. Using in vitro competition assays, we show that these CRISPR-Cas-encoding delivery plasmids, or CRISPR-Cas antimicrobials, can reduce the occurrence of antibiotic resistance in enterococcal populations in a sequence-specific manner. Furthermore, we demonstrate that deployment of CRISPR-Cas antimicrobials in the murine intestine reduces the occurrence of antibiotic-resistant E. faecalis by several orders of magnitude. Finally, we show that E. faecalis donor strains harboring CRISPR-Cas antimicrobials are immune to uptake of antibiotic resistance determinants in vivo. Our results demonstrate that conjugative delivery of CRISPR-Cas antimicrobials may be adaptable for future deployment from probiotic bacteria for exact targeting of defined MDR bacteria or for precision engineering of polymicrobial communities in the mammalian intestine.

scholarly journals Molecular detection of antibiotic resistance genes in multidrug-resistant Staphylococcus aureus isolates from dog dental plaque

2019 ◽  
Vol 22 (4) ◽  
pp. 419-427
Author(s):  
S. Nouri Gharajalar ◽  
M. Onsori
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Multiplex Pcr ◽  
Resistance Genes ◽  
Dental Plaque ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Pcr Assay ◽  
Multiplex Pcr Assay

Multidrug resistant Staphylococcus aureus strains are a major health care problem both in humans and animals. In this work we described three multiplex PCR assays for detection of clinically relevant antibiotic resistance genes in S. aureus isolated from dog dental plaques. Thirty dental plaque samples were collected; then cultural, biochemical and molecular tests performed for isolation and identification of S. aureus from samples. The antibiotic susceptibility of the isolates were checked by Kirby Bauer disc diffusion method and the prevalence of antibiotic resistance genes determined using multiplex PCR assay. As a result S. aureus was isolated from 18 dog plaque samples. Fifteen of these isolates were resistant to penicillin. The mecA gene was more prevalent than blaZ among penicillin-resistant bacteria. Ten of the isolates were resistant to tetracycline. The percentage of tetM was higher than tetK among them. Also, 10 of the isolates were resistant to cefazolin among them bla TEM detected in higher rate than blaSHV and blaOXA-1. Hence multiplex PCR assay is a suitable method for detection of antibiotic resistance patterns of S. aureus isolates.

scholarly journals Antibiotics in Food Chain: The Consequences for Antibiotic Resistance

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 688
Author(s):  
Shashi B. Kumar ◽  
Shanvanth R. Arnipalli ◽  
Ouliana Ziouzenkova
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Food Chain ◽  
Bacterial Infections ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Alternative Strategies ◽  
Antibiotic Resistant ◽  
Continuous Use

Antibiotics have been used as essential therapeutics for nearly 100 years and, increasingly, as a preventive agent in the agricultural and animal industry. Continuous use and misuse of antibiotics have provoked the development of antibiotic resistant bacteria that progressively increased mortality from multidrug-resistant bacterial infections, thereby posing a tremendous threat to public health. The goal of our review is to advance the understanding of mechanisms of dissemination and the development of antibiotic resistance genes in the context of nutrition and related clinical, agricultural, veterinary, and environmental settings. We conclude with an overview of alternative strategies, including probiotics, essential oils, vaccines, and antibodies, as primary or adjunct preventive antimicrobial measures or therapies against multidrug-resistant bacterial infections. The solution for antibiotic resistance will require comprehensive and incessant efforts of policymakers in agriculture along with the development of alternative therapeutics by experts in diverse fields of microbiology, biochemistry, clinical research, genetic, and computational engineering.

scholarly journals Characterization of antibiotic resistance genes in the species of the rumen microbiota

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yasmin Neves Vieira Sabino ◽  
Mateus Ferreira Santana ◽  
Linda Boniface Oyama ◽  
Fernanda Godoy Santos ◽  
Ana Júlia Silva Moreira ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Animal Health ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Ruminal Bacteria ◽  
Genes Encoding

AbstractInfections caused by multidrug resistant bacteria represent a therapeutic challenge both in clinical settings and in livestock production, but the prevalence of antibiotic resistance genes among the species of bacteria that colonize the gastrointestinal tract of ruminants is not well characterized. Here, we investigate the resistome of 435 ruminal microbial genomes in silico and confirm representative phenotypes in vitro. We find a high abundance of genes encoding tetracycline resistance and evidence that the tet(W) gene is under positive selective pressure. Our findings reveal that tet(W) is located in a novel integrative and conjugative element in several ruminal bacterial genomes. Analyses of rumen microbial metatranscriptomes confirm the expression of the most abundant antibiotic resistance genes. Our data provide insight into antibiotic resistange gene profiles of the main species of ruminal bacteria and reveal the potential role of mobile genetic elements in shaping the resistome of the rumen microbiome, with implications for human and animal health.

scholarly journals Metagenome-Wide Analysis of Rural and Urban Surface Waters and Sediments in Bangladesh Identifies Human Waste as a Driver of Antibiotic Resistance

mSystems ◽  
2021 ◽  
Author(s):  
Ross Stuart McInnes ◽  
Md Hassan uz-Zaman ◽  
Imam Taskin Alam ◽  
Siu Fung Stanley Ho ◽  
Robert A. Moran ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Surface Waters ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Middle Income ◽  
Antibiotic Resistant ◽  
Human Waste ◽  
Middle Income Countries ◽  
Rural And Urban

Low- and middle-income countries (LMICs) have higher burdens of multidrug-resistant infections than high-income countries, and there is thus an urgent need to elucidate the drivers of the spread of antibiotic-resistant bacteria in LMICs. Here, we study the diversity and abundance of antibiotic resistance genes in surface water and sediments from rural and urban settings in Bangladesh.

scholarly journals Imcroporin, a New Cationic Antimicrobial Peptide from the Venom of the Scorpion Isometrus maculates

2009 ◽  
Vol 53 (8) ◽  
pp. 3472-3477 ◽  
Author(s):  
Zhenhuan Zhao ◽  
Yibao Ma ◽  
Chao Dai ◽  
Ruiming Zhao ◽  
SongRyong Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptide ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Lead Compound ◽  
Cationic Antimicrobial Peptide ◽  
Antibiotic Resistant ◽  
Multidrug Resistant Pathogens ◽  
Conventional Antibiotics

ABSTRACT The pace of resistance against antibiotics almost exceeds that of the development of new drugs. As many bacteria have become resistant to conventional antibiotics, new drugs or drug resources are badly needed to combat antibiotic-resistant pathogens, like methicillin-resistant Staphylococcus aureus (MRSA). Antimicrobial peptides, rich sources existing in nature, are able to effectively kill multidrug-resistant pathogens. Here, imcroporin, a new antimicrobial peptide, was screened and isolated from the cDNA library of the venomous gland of Isometrus maculates. The MIC of imcroporin against MRSA was 50 μg/ml, 8-fold lower than that of cefotaxime and 40-fold lower than that of penicillin. Imcroporin killed bacteria rapidly in vitro, inhibited bacterial growth, and cured infected mice. These results revealed that imcroporin could be considered a potential anti-infective drug or lead compound, especially for treating antibiotic-resistant pathogens.

Retail Ready-to-Eat Food as a Potential Vehicle for Staphylococcus spp. Harboring Antibiotic Resistance Genes

2014 ◽  
Vol 77 (6) ◽  
pp. 993-998 ◽  
Author(s):  
WIOLETA CHAJĘCKA-WIERZCHOWSKA ◽  
ANNA ZADERNOWSKA ◽  
BEATA NALEPA ◽  
MAGDA SIERPI´NSKA ◽  
ŁUCJA ŁANIEWSKA-TROKENHEIM
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Meca Gene ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Cured Meats ◽  
Staphylococcus Spp

Ready-to-eat (RTE) food, which does not need thermal processing before consumption, could be a vehicle for the spread of antibiotic-resistant microorganisms. As part of general microbiological safety checks, staphylococci are routinely enumerated in these kinds of foods. However, the presence of antibiotic-resistant staphylococci in RTE food is not routinely investigated, and data are only available from a small number of studies. The present study evaluated the pheno- and genotypical antimicrobial resistance profile of Staphylococcus spp. isolated from 858 RTE foods (cheeses, cured meats, sausages, smoked fishes, salads). Of 113 strains isolated, S. aureus was the most prevalent species, followed by S. xylosus, S. saprophyticus, and S. epidermidis. More than half (54.9%) of the isolates were resistant to at least one class of tested antibiotic; of these, 35.4% of the strains were classified as multidrug resistant. Most of the isolates were resistant to cefoxitin (49.6%), followed by clindamycin (39.3%), tigecycline (27.4%), quinupristin-dalfopristin (22.2%), rifampin (20.5%), tetracycline (17.9%), and erythromycin (8.5%). All methicillin-resistant staphylococci harbored the mecA gene. Among the isolates resistant to at least one antibiotic, 38 harbored tetracycline resistance determinant tet(M), 24 harbored tet(L), and 9 harbored tet(K). Of the isolates positive for tet(M) genes, 34.2% were positive for the Tn916-Tn1545–like integrase family gene. Our results indicated that retail RTE food could be considered an important route for the transmission of antibiotic-resistant bacteria harboring multiple antibiotic resistance genes.

scholarly journals Isolation and molecular characterization of multidrug-resistant Escherichia coli from chicken meat

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Md. Masudur Rahman ◽  
Asmaul Husna ◽  
Hatem A. Elshabrawy ◽  
Jahangir Alam ◽  
Nurjahan Yasmin Runa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Broiler Chicken ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Chicken Meat ◽  
The Other ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Layer Chicken

AbstractAntibiotic-resistant Escherichia coli (E. coli) are common in retail poultry products. In this study, we aimed to isolate and characterize multidrug resistant (MDR) E. coli in raw chicken meat samples collected from poultry shops in Sylhet division, Bangladesh, as well as to determine correlation between resistance phenotype and genotype. A total of 600 chicken meat swabs (divided equally between broiler and layer farms, n = 300 each) were collected and the isolates identified as E. coli (n = 381) were selected. Disc diffusion antimicrobial susceptibility assay showed resistance of these isolates to ampicillin, erythromycin, tetracycline, streptomycin, trimethoprim-sulfamethoxazole, chloramphenicol, and gentamicin. Polymerase chain reaction (PCR) identified several antibiotic resistance genes (ARGs) in our isolates. Among these ARGs, the prevalence of tetA (for tetracycline) was the highest (72.58%) in broiler chicken isolates, followed by sul1 (for sulfonamide; 44.16%), aadA1 (for streptomycin; 33.50%), ereA (for erythromycin; 27.41%), aac-3-IV (for gentamicin; 25.38%), and the two genes cmlA (24.87%) and catA1 (8.63%) for chloramphenicol. On the other hand, the respective prevalence in layer chicken isolates were 82.06%, 47.83%, 35.87%, 35.33%, 23.91%, 19.02%, and 5.43%. Furthermore, 49.23% of the isolates from broiler chicken were MDR, with the presence of multiple antibiotic resistance genes, including 3 (40.11%) and 4 (9.13%) genes. On the other hand, 51.09% of layer chicken E. coli isolates were MDR, with 3, 4 or 5 ARGs detected in 36.41%, 14.13%, and 0.54% of the isolates, respectively. We also found that 12.8% of broiler chicken E. coli isolates and 7.61% of layer chicken isolates carried genes coding for extended-spectrum SHV beta-lactamases. Lastly, we report the presence of the AmpC beta-lactamase producing gene (CITM) in 4.56% and 3.26% of broiler and layer chicken E. coli isolates, respectively. We found significant correlations between most of the antimicrobial resistant phenotypes and genotypes observed among the investigated E. coli isolates. Our findings highlight the need for the prudent use of antimicrobials in chickens to minimize the development of antibiotic-resistant bacterial strains.

scholarly journals Characterization of Tn7-like transposons and its related antibiotic resistance among Enterobacteriaceae from livestock and poultry in China

2020 ◽  
Author(s):  
Juan He ◽  
Cui Li ◽  
Pengfei Cui ◽  
Hongning Wang
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Horizontal Transmission ◽  
Antibiotic Resistance Genes ◽  
Variable Region ◽  
Multidrug Resistant ◽  
Antibiotic Resistant ◽  
E Coli ◽  
New Type

Abstract Background: This study was aimed to investigate the prevalence and structure of Tn7-like in Enterobacteriaceae from livestock and poultry as well as their possible role as reservoir of antibiotic resistance genes (ARGs).Methods: Polymerase chain reaction (PCR) and DNA sequencing analyses were used for the characterization of Tn7-like, associated integrons and ARGs. The antimicrobial resistance profile of the isolates was examined by using disc diffusion test.Results: Three hundred and seventy-eight Tn7-like-positive strains of Enterobacteriaceae were isolated, and included E. coli (128), Proteus(150), K. pneumonia(17), Salmonella(13), M. morganii (21) and A. baumannii(1), wherein high resistance was observed for Trimethoprim/Sulfamethoxazole and Streptomycin, and fifty percent of the strains were multidrug-resistant. Integrons class 2 were detected in all of the isolates and there are high frequency mutation sites especially in 535, a stop mutation. Variable region of class 2 integrons carried same gene cassettes, namely aadA1-sat2-dfrA1. From the 378 isolated strains, we found a new type of Tn7-like on a plasmid, named Tn6765.Conclusions: These findings proved that the Tn7-like can contribute to the horizontal transmission of antibiotic resistant genes in livestock and poultry. As potential vessels for antibiotic resistance genes (ARGs), Tn7-like could not be ignored due to their efficient transfer ability in environments.

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