Enrichment of antibiotic resistance genes in soil receiving composts derived from swine manure, yard wastes, or food wastes, and evidence for multiyear persistence of swine Clostridium spp.

2018 ◽  
Vol 64 (3) ◽  
pp. 201-208 ◽  
Author(s):  
Andrew Scott ◽  
Yuan-Ching Tien ◽  
Craig F. Drury ◽  
W. Daniel Reynolds ◽  
Edward Topp
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Swine Manure ◽  
Organic Amendments ◽  
Antibiotic Resistance Genes ◽  
Gene Target ◽  
Soil Dna ◽  
Yard Waste ◽  
The Impact ◽  
Clostridium Spp

The impact of amendment with swine manure compost (SMC), yard waste compost (YWC), or food waste compost (FWC) on the abundance of antibiotic resistance genes in soil was evaluated. Following a commercial-scale application of the composts in a field experiment, soils were sampled periodically for a decade, and archived air-dried. Soil DNA was extracted and gene targets quantified by qPCR. Compared with untreated control soil, all 3 amendment types increased the abundance of gene targets for up to 4 years postapplication. The abundance of several gene targets was much higher in soil amended with SMC than in soil receiving either YWC or FWC. The gene target ermB remained higher in the SMC treatment for a decade postapplication. Clostridia were significantly more abundant in the SMC-amended soil throughout the decade following application. Eight percent of Clostridium spp. isolates from the SMC treatment carried ermB. Overall, addition of organic amendments to soils has the potential to increase the abundance of antibiotic resistance genes. Amendments of fecal origin, such as SMC, will in addition entrain bacteria carrying antibiotic resistance genes. Environmentally recalcitrant clostridia, and the antibiotic resistance genes that they carry, will persist for many years under field conditions following the application of SMC.

Metagenomic analysis of effects of oxytetracycline and copper on antibiotic resistance genes and associated pathogenic hosts in swine manure compost

2020 ◽  
Author(s):  
Honghong Guo ◽  
jie gu ◽  
Xiaojuan Wang ◽  
Zilin Song ◽  
Xun Qian ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Swine Manure ◽  
Antibiotic Resistance Genes ◽  
Feed Additives ◽  
Poultry Feed ◽  
Risk Scores ◽  
Composting Process ◽  
Positive Effects

Abstract Background: The proliferation of antibiotic resistance genes (ARGs) in compost and their horizontal transfer to human pathogenic bacteria (HPB) may lead to the failure of human antibiotics. However, the antibiotic resistome in compost has not been comprehensively characterized. This study used a metagenomic approach to obtain new insights into the effects of oxytetracycline (OTC) and copper (Cu) on the antibiotic resistome during swine manure composting and the risks posed to human health. Results: The results showed that composting reduced the abundances and diversity of ARGs and HPB in swine manure. In total, 289 ARG subtypes and 19 ARG types were detected in the samples with abundances ranging from 1.08 ´ 10 –1 to 9.39 ´ 10 –1 copies/16S rRNA, which mainly encoded tetracycline, aminoglycoside, and macrolide–lincosamide–streptogramin (MLS) resistance genes. The application of OTC and Cu, especially the combined application, exacerbated the compost resistome risk scores and specific ARG subtypes responded differently. Tetracycline, multidrug, and MLS resistance genes mainly affected resistance profiles of HPB throughout the composting process. HPB and intI1 had significant positive effects on determining the ARG profiles during the composting process, and the co-selective effect of heavy metals may increase the abundances of ARGs via strong positive effects on intI1 . In addition, the effect of mobile genetic elements on the horizontal gene transfer of ARGs should not be ignored. Conclusions: This study of the antibiotic resistome in compost indicates the need for effective regulation of the misuse of livestock and poultry feed additives in order to minimize the spread of the antibiotic resistome in agro-ecosystems and decrease the potential risk to public health. Keywords: Antibiotic resistome; Composting; Metagenome; Pathogenic host; Swine manure

scholarly journals The Occurrence of Antibiotic Resistance Genes in an Urban River in Nepal

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 450 ◽  
Author(s):  
Ocean Thakali ◽  
Sarmila Tandukar ◽  
John Brooks ◽  
Samendra Sherchan ◽  
Jeevan Sherchand ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Anthropogenic Activities ◽  
Quantitative Polymerase Chain Reaction ◽  
Antibiotic Resistance Genes ◽  
Urban River ◽  
Class 1 Integron ◽  
Upstream Site ◽  
Class 1 ◽  
The Impact

Urban rivers affected by anthropogenic activities can act as reservoirs of antibiotic resistance genes (ARGs). This study aimed to describe the occurrence of selected ARGs (blaTEM, ermF, mecA, and tetA) and a class 1 integron (intI1) in an urban river in Nepal. A total of 18 water samples were collected periodically from upstream, midstream, and downstream sites along the Bagmati River over a 1-year period. All ARGs except mecA and intI1 were consistently detected by a quantitative polymerase chain reaction in the midstream and downstream sites, with concentrations ranging from 3.1 to 7.8 log copies/mL. ARG abundance was significantly lower at the upstream site (p < 0.05), reflecting the impact of anthropogenic activities on increasing concentrations of ARGs at midstream and downstream sites. Our findings demonstrate the presence of clinically relevant ARGs in the urban river water of Nepal, suggesting a need for mitigating strategies to prevent the spread of antibiotic resistance in the environment.

scholarly journals Cohorting KPC+ Klebsiella pneumoniae (KPC-Kp)–positive patients: A genomic exposé of cross-colonization hazards in a long-term acute-care hospital (LTACH)

2020 ◽  
Vol 41 (10) ◽  
pp. 1162-1168
Author(s):  
Shawn E. Hawken ◽  
Mary K. Hayden ◽  
Karen Lolans ◽  
Rachel D. Yelin ◽  
Robert A. Weinstein ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Acute Care ◽  
Resistance Genes ◽  
Acute Care Hospital ◽  
Antibiotic Resistance Genes ◽  
Care Hospital ◽  
Cross Transmission ◽  
The Impact

AbstractObjective:Cohorting patients who are colonized or infected with multidrug-resistant organisms (MDROs) protects uncolonized patients from acquiring MDROs in healthcare settings. The potential for cross transmission within the cohort and the possibility of colonized patients acquiring secondary isolates with additional antibiotic resistance traits is often neglected. We searched for evidence of cross transmission of KPC+ Klebsiella pneumoniae (KPC-Kp) colonization among cohorted patients in a long-term acute-care hospital (LTACH), and we evaluated the impact of secondary acquisitions on resistance potential.Design:Genomic epidemiological investigation.Setting:A high-prevalence LTACH during a bundled intervention that included cohorting KPC-Kp–positive patients.Methods:Whole-genome sequencing (WGS) and location data were analyzed to identify potential cases of cross transmission between cohorted patients.Results:Secondary KPC-Kp isolates from 19 of 28 admission-positive patients were more closely related to another patient’s isolate than to their own admission isolate. Of these 19 cases, 14 showed strong genomic evidence for cross transmission (<10 single nucleotide variants or SNVs), and most of these patients occupied shared cohort floors (12 patients) or rooms (4 patients) at the same time. Of the 14 patients with strong genomic evidence of acquisition, 12 acquired antibiotic resistance genes not found in their primary isolates.Conclusions:Acquisition of secondary KPC-Kp isolates carrying distinct antibiotic resistance genes was detected in nearly half of cohorted patients. These results highlight the importance of healthcare provider adherence to infection prevention protocols within cohort locations, and they indicate the need for future studies to assess whether multiple-strain acquisition increases risk of adverse patient outcomes.

scholarly journals Analysis of Antibiotic Resistance Genes in Multidrug-Resistant Acinetobacter sp. Isolates from Military and Civilian Patients Treated at the Walter Reed Army Medical Center

2006 ◽  
Vol 50 (12) ◽  
pp. 4114-4123 ◽  
Author(s):  
Kristine M. Hujer ◽  
Andrea M. Hujer ◽  
Edward A. Hulten ◽  
Saralee Bajaksouzian ◽  
Jennifer M. Adams ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Medical Center ◽  
Antibiotic Resistance Genes ◽  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Walter Reed Army Medical ◽  
Army Medical ◽  
Starting Point ◽  
The Impact

ABSTRACT Military medical facilities treating patients injured in Iraq and Afghanistan have identified a large number of multidrug-resistant (MDR) Acinetobacter baumannii isolates. In order to anticipate the impact of these pathogens on patient care, we analyzed the antibiotic resistance genes responsible for the MDR phenotype in Acinetobacter sp. isolates collected from patients at the Walter Reed Army Medical Center (WRAMC). Susceptibility testing, PCR amplification of the genetic determinants of resistance, and clonality were determined. Seventy-five unique patient isolates were included in this study: 53% were from bloodstream infections, 89% were resistant to at least three classes of antibiotics, and 15% were resistant to all nine antibiotics tested. Thirty-seven percent of the isolates were recovered from patients nosocomially infected or colonized at the WRAMC. Sixteen unique resistance genes or gene families and four mobile genetic elements were detected. In addition, this is the first report of bla OXA-58-like and bla PER-like genes in the U.S. MDR A. baumannii isolates with at least eight identified resistance determinants were recovered from 49 of the 75 patients. Molecular typing revealed multiple clones, with eight major clonal types being nosocomially acquired and with more than 60% of the isolates being related to three pan-European types. This report gives a “snapshot” of the complex genetic background responsible for antimicrobial resistance in Acinetobacter spp. from the WRAMC. Identifying genes associated with the MDR phenotype and defining patterns of transmission serve as a starting point for devising strategies to limit the clinical impact of these serious infections.

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