scholarly journals 702. Zinc Blockade of SOS Response Inhibits Horizontal Transfer of Antibiotic Resistance Genes in Enteric Bacteria

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S253-S253
Author(s):  
John Crane ◽  
Mark Sutton ◽  
Muhammad Cheema ◽  
Michael Olyer
Keyword(s):  
Dna Damage ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Horizontal Transfer ◽  
Antibiotic Resistance Genes ◽  
Sos Response ◽  
Enteric Bacteria ◽  
Extracellular Dna ◽  
In Vitro Assays ◽  
E Coli

Abstract Background The SOS response is a conserved response to DNA damage that is found in Gram negative and Gram-positive bacteria. When DNA damage is sustained and severe, activation of error-prone DNA polymerases can induce a higher mutation rate then normally observed, which is called the mutator phenotype or hypermutation. We previously showed that zinc blocked the hypermutation response induced by quinolone antibiotics and mitomycin C in E. coli and Klebsiella pneumoniae (Bunnell BE, Escobar JF, Bair KL, Sutton MD, Crane JK (2017). Zinc blocks SOS-induced antibiotic resistance via inhibition of RecA in Escherichia coli. PLoS ONE 12(5): e0178303. https://doi.org/10.1371/journal.pone.0178303.) In addition to causing copying errors in DNA replication, Beaber et al. showed that induction of the SOS response increased the frequency of horizontal gene transfer into Vibrio cholerae, an organism naturally competent at uptake of extracellular DNA. (Beaber JW, Hochhut B, Waldor MK. 2003. SOS response promotes horizontal dissemination of antibiotic resistance genes. Nature 427:72–74.) Methods. In this study, we tested whether induction of the SOS response could induce transfer of antibiotic resistance from Enterobacter cloacae into E. coli, and whether zinc could inhibit that inter-species transfer of antibiotic resistance. Results. Ciprofloxacin, an inducer of the SOS response, increased the rate of transfer of an extended spectrum β-lactamase (ESBL) gene from Enterobacter into a susceptible E. coli strain. Zinc blocked SOS-induced horizontal transfer of §-lactamase into E. coli. Other divalent metals, such as iron and manganese, failed to inhibit these responses. Conclusion. In vitro assays showed that zinc blocked the ability of RecA to bind to ssDNA, an early step in the SOS response, suggesting the mechanism by which zinc blocks the SOS response. Disclosures All authors: No reported disclosures.

scholarly journals Mechanisms of Resistance in Multiple-Antibiotic-Resistant Escherichia coli Strains of Human, Animal, and Food Origins

2004 ◽  
Vol 48 (10) ◽  
pp. 3996-4001 ◽  
Author(s):  
Yolanda Sáenz ◽  
Laura Briñas ◽  
Elena Domínguez ◽  
Joaquim Ruiz ◽  
Myriam Zarazaga ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Amino Acid ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Mechanisms Of Resistance ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Class 1 ◽  
Human Animal

ABSTRACT Seventeen multiple-antibiotic-resistant nonpathogenic Escherichia coli strains of human, animal, and food origins showed a wide variety of antibiotic resistance genes, many of them carried by class 1 and class 2 integrons. Amino acid changes in MarR and mutations in marO were identified for 15 and 14 E. coli strains, respectively.

scholarly journals Antibiotic-resistant Escherichia coli and Salmonella spp. associated with dairy cattle and farm environment having public health significance

2019 ◽  
Vol 12 (7) ◽  
pp. 984-993 ◽  
Author(s):  
Md. Abdus Sobur ◽  
Abdullah Al Momen Sabuj ◽  
Ripon Sarker ◽  
A. M. M. Taufiqur Rahman ◽  
S. M. Lutful Kabir ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
One Health ◽  
Dairy Farm ◽  
Antibiotic Resistance Genes ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
E Coli

Aim: The present study was carried out to determine load of total bacteria, Escherichia coli and Salmonella spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach. Materials and Methods: A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the E. coli and Salmonella spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR. The pathogenic strains of E. coli stx1, stx2, and rfbO157 were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes ereA, tetA, tetB, and SHV were performed by PCR. Results: The mean total bacterial count, E. coli and Salmonella spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of E. coli and 136 (56.67%) isolates of Salmonella spp. were recovered through cultural and molecular tests. Among the 180 E. coli isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which stx1 was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic E. coli. Antibiotic sensitivity test revealed that both E. coli and Salmonella spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was tetA (80.51-84.74%) in E. coli and Salmonella spp. and SHV genes were the lowest one (22.06-25%). Conclusion: Dairy farm and their environmental components carry antibiotic-resistant pathogenic E. coli and Salmonella spp. that are potential threat for human health which requires a one-health approach to combat the threat.

Contamination of hay and haylage with enteric bacteria and selected antibiotic resistance genes following fertilization with dairy manure or biosolids.

2022 ◽  
Author(s):  
Andrew Scott ◽  
Roger Murray ◽  
Yuan-Ching Tien ◽  
Edward Topp
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Field Experiments ◽  
Antibiotic Resistance Genes ◽  
Enteric Bacteria ◽  
Dairy Manure ◽  
Plate Count ◽  
Growing Seasons ◽  
Route Of Exposure ◽  
And Control

The present study evaluated if enteric bacteria or antibiotic resistance genes carried in fecal amendments contaminate the hay at harvest, representing a potential route of exposure to ruminants that consume the hay. In field experiments, dairy manure was applied to a hay field for three successive growing seasons, and biosolids applied to a hay field for one growing season. Various enteric bacteria in the amendments were enumerated by viable plate count, and selected gene targets were quantified by qPCR. Key findings include the following: At harvest, hay receiving dairy manure or biosolids did not carry more viable enteric bacteria than did hay from unamended control plots. Fermentation of hay did not result in a detectable increase in viable enteric bacteria. The application of dairy manure or biosolids did result in a few gene targets being more abundant on hay at the first harvest. Fermentation of hay did result in an increase in the abundance of gene targets, but this occurred both with hay from amended and control plots. Overall, application of fecal amendments will result in an increase in the abundance of some gene targets associated with antibiotic resistance on first cut hay.

scholarly journals Predicting Antibiotic Resistance in Gram-Negative Bacilli from Resistance Genes

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
G. Terrance Walker ◽  
Julia Quan ◽  
Stephen G. Higgins ◽  
Nikhil Toraskar ◽  
Weizhong Chang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Unknown Origin ◽  
Bacterial Isolates ◽  
Antibiotic Resistant ◽  
Predictive Values ◽  
Content Type ◽  
Phenotypic Resistance ◽  
E Coli

ABSTRACT We developed a rapid high-throughput PCR test and evaluated highly antibiotic-resistant clinical isolates of Escherichia coli (n = 2,919), Klebsiella pneumoniae (n = 1,974), Proteus mirabilis (n = 1,150), and Pseudomonas aeruginosa (n = 1,484) for several antibiotic resistance genes for comparison with phenotypic resistance across penicillins, cephalosporins, carbapenems, aminoglycosides, trimethoprim-sulfamethoxazole, fluoroquinolones, and macrolides. The isolates originated from hospitals in North America (34%), Europe (23%), Asia (13%), South America (12%), Africa (7%), or Oceania (1%) or were of unknown origin (9%). We developed statistical methods to predict phenotypic resistance from resistance genes for 49 antibiotic-organism combinations, including gentamicin, tobramycin, ciprofloxacin, levofloxacin, trimethoprim-sulfamethoxazole, ertapenem, imipenem, cefazolin, cefepime, cefotaxime, ceftazidime, ceftriaxone, ampicillin, and aztreonam. Average positive predictive values for genotypic prediction of phenotypic resistance were 91% for E. coli, 93% for K. pneumoniae, 87% for P. mirabilis, and 92% for P. aeruginosa across the various antibiotics for this highly resistant cohort of bacterial isolates.

Sign in / Sign up

Export Citation Format

Share Document