scholarly journals Antimicrobial Susceptibility Testing and Tentative Epidemiological Cutoff Values for FiveBacillusSpecies Relevant for Use as Animal Feed Additives or for Plant Protection

2018 ◽  
Vol 84 (19) ◽  
Author(s):  
Yvonne Agersø ◽  
Birgitte Stuer-Lauridsen ◽  
Karin Bjerre ◽  
Michelle Geervliet Jensen ◽  
Eric Johansen ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Animal Feed ◽  
Bacterial Species ◽  
Feed Additives ◽  
Content Type ◽  
Cutoff Values ◽  
Antimicrobial Resistance Genes ◽  
Species Specific

ABSTRACTBacillus megaterium(n= 29),Bacillus velezensis(n= 26),Bacillus amyloliquefaciens(n= 6),Bacillus paralicheniformis(n= 28), andBacillus licheniformis(n= 35) strains from different sources, origins, and time periods were tested for the MICs for nine antimicrobial agents by the CLSI-recommended method (Mueller-Hinton broth, 35°C, for 18 to 20 h), as well as with a modified CLSI method (Iso-Sensitest [IST] broth, 37°C [35°C forB. megaterium], 24 h). This allows a proposal of species-specific epidemiological cutoff values (ECOFFs) for the interpretation of antimicrobial resistance in these species. MICs determined by the modified CLSI method were 2- to 16-fold higher than with the CLSI-recommended method for several antimicrobials. The MIC distributions differed between species for five of the nine antimicrobials. Consequently, use of the modified CLSI method and interpretation of resistance by use of species-specific ECOFFs is recommended. The genome sequences of all strains were determined and used for screening for resistance genes against the ResFinder database and for multilocus sequence typing. A putative chloramphenicol acetyltransferase (cat) gene was found in oneB. megateriumstrain with an elevated chloramphenicol MIC compared to the otherB. megateriumstrains. InB. velezensisandB. amyloliquefaciens, a putative tetracycline efflux gene,tet(L), was found in all strains (n= 27) with reduced tetracycline susceptibility but was absent in susceptible strains. AllB. paralicheniformisand 23% ofB. licheniformisstrains had elevated MICs for erythromycin and harboredermD. The presence of these resistance genes follows taxonomy suggesting they may be intrinsic rather than horizontally acquired. Reduced susceptibility to chloramphenicol, streptomycin, and clindamycin could not be explained in all species.IMPORTANCEWhen commercializing bacterial strains, likeBacillusspp., for feed applications or plant bioprotection, it is required that the strains are free of acquired antimicrobial resistance genes that could potentially spread to pathogenic bacteria, thereby adding to the pool of resistance genes that may cause treatment failures in humans or animals. Conversely, if antimicrobial resistance is intrinsic to a bacterial species, the risk of spreading horizontally to other bacteria is considered very low. Reliable susceptibility test methods and interpretation criteria at the species level are needed to accurately assess antimicrobial resistance levels. In the present study, tentative ECOFFs for fiveBacillusspecies were determined, and the results showed that the variation in MICs followed the respective species. Moreover, putative resistance genes, which were detected by whole-genome sequencing and suggested to be intrinsic rather that acquired, could explain the resistance phenotypes in most cases.

The Role of Gut Microbiota in Antimicrobial Resistance: A Mini-Review

2020 ◽  
Vol 18 (3) ◽  
pp. 201-206
Author(s):  
Farzaneh Firoozeh ◽  
Mohammad Zibaei
Keyword(s):  
Antimicrobial Resistance ◽  
Gut Microbiota ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Human Gut ◽  
Opportunistic Bacteria ◽  
Antimicrobial Resistance Genes ◽  
Opportunistic Pathogenic

In the current world, development and spread of antimicrobial resistance among bacteria have been raised and antimicrobial-resistant bacteria are one of the most important health challenges. The antimicrobial resistance genes can easily move and transfer among diverse bacterial species and strains. The human gut microbiota consists of a dense microbial population including trillions of microorganisms. Recently, studies have shown that the bacteria which make the major part of gut microbiota, harbor a variety of antimicrobial resistance genes which are called gut resistome. The transfer of resistance genes from commensal bacteria to gut-resident opportunistic bacteria may involve in the emergence of multi-drug resistant (MDR) bacteria. Thus, the main aim of the current mini-review was to study the mechanisms of exchange of antimicrobial resistance genes by commensal and opportunistic pathogenic bacteria in the human gut.

scholarly journals Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

2014 ◽  
Vol 80 (12) ◽  
pp. 3656-3666 ◽  
Author(s):  
Basanta Kumar Biswal ◽  
Ramzi Khairallah ◽  
Kareem Bibi ◽  
Alberto Mazza ◽  
Ronald Gehr ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Peracetic Acid ◽  
Content Type ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Antimicrobial Resistance Gene ◽  
Municipal Wastewaters ◽  
The Impact

ABSTRACTWastewater discharges may increase the populations of pathogens, includingEscherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenicEscherichia coli(UPEC), the most abundantE. colipathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766E. coliisolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm2and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.

scholarly journals Merging Metagenomics and Spatial Epidemiology To Understand the Distribution of Antimicrobial Resistance Genes from Enterobacteriaceae in Wild Owls

2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Elizabeth A. Miller ◽  
Julia B. Ponder ◽  
Michelle Willette ◽  
Timothy J. Johnson ◽  
Kimberly L. VanderWaal
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Spatial Epidemiology ◽  
Anthropogenic Sources ◽  
Resistant Bacteria ◽  
Metagenomic Sequencing ◽  
Wild Animals ◽  
Natural Ecosystems ◽  
Content Type ◽  
Antimicrobial Resistance Genes

ABSTRACT Antimicrobial resistance (AMR) is a well-documented phenomenon in bacteria from many natural ecosystems, including wild animals. However, the specific determinants and spatial distribution of resistant bacteria and antimicrobial resistance genes (ARGs) in the environment remain incompletely understood. In particular, information regarding the importance of anthropogenic sources of AMR relative to that of other biological and ecological influences is lacking. We conducted a cross-sectional study of AMR in great horned owls (Bubo virginianus) and barred owls (Strix varia) admitted to a rehabilitation center in the midwestern United States. A combination of selective culture enrichment and shotgun metagenomic sequencing was used to identify ARGs from Enterobacteriaceae. Overall, the prevalence of AMR was comparable to that in past studies of resistant Enterobacteriaceae in raptors, with acquired ARGs being identified in 23% of samples. Multimodel regression analyses identified seasonality and owl age to be important predictors of the likelihood of the presence of ARGs, with birds sampled during warmer months being more likely to harbor ARGs than those sampled during cooler months and with birds in their hatch year being more likely to harbor β-lactam ARGs than adults. Beyond host-specific determinants, ARG-positive owls were also more likely to be recovered from areas of high agricultural land cover. Spatial clustering analyses identified a significant high-risk cluster of tetracycline resistance gene-positive owls in the southern sampling range, but this could not be explained by any predictor variables. Taken together, these results highlight the complex distribution of AMR in natural environments and suggest that both biological and anthropogenic factors play important roles in determining the emergence and persistence of AMR in wildlife. IMPORTANCE Antimicrobial resistance (AMR) is a multifaceted problem that poses a worldwide threat to human and animal health. Recent reports suggest that wildlife may play an important role in the emergence, dissemination, and persistence of AMR. As such, there have been calls for better integration of wildlife into current research on AMR, including the use of wild animals as biosentinels of AMR contamination in the environment. A One Health approach can be used to gain a better understanding of all AMR sources and pathways, particularly those at the human-animal-environment interface. Our study focuses on this interface in order to assess the effect of human-impacted landscapes on AMR in a wild animal. This work highlights the value of wildlife rehabilitation centers for environmental AMR surveillance and demonstrates how metagenomic sequencing within a spatial epidemiology framework can be used to address questions surrounding AMR complexity in natural ecosystems.

scholarly journals New York City House Mice (Mus musculus) as Potential Reservoirs for Pathogenic Bacteria and Antimicrobial Resistance Determinants

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. e00624-18 ◽  
Author(s):  
Simon H. Williams ◽  
Xiaoyu Che ◽  
Ashley Paulick ◽  
Cheng Guo ◽  
Bohyun Lee ◽  
...  
Keyword(s):  
New York ◽  
New York City ◽  
Antimicrobial Resistance ◽  
York City ◽  
Pathogenic Bacteria ◽  
Gastrointestinal Disease ◽  
House Mice ◽  
Urban Centers ◽  
Content Type ◽  
Antimicrobial Resistance Genes

ABSTRACTHouse mice (Mus musculus) thrive in large urban centers worldwide. Nonetheless, little is known about the role that they may play in contributing to environmental contamination with potentially pathogenic bacteria. Here, we describe the fecal microbiome of house mice with emphasis on detection of pathogenic bacteria and antimicrobial resistance genes by molecular methods. Four hundred sixteen mice were collected from predominantly residential buildings in seven sites across New York City over a period of 13 months. 16S rRNA sequencing identifiedBacteroidetesas dominant and revealed high levels ofProteobacteria. A targeted PCR screen of 11 bacteria, as indicated by 16S rRNA analyses, found that mice are carriers of several gastrointestinal disease-causing agents, includingShigella,Salmonella,Clostridium difficile, and diarrheagenicEscherichia coli. Furthermore, genes mediating antimicrobial resistance to fluoroquinolones (qnrB) and β-lactam drugs (blaSHVandblaACT/MIR) were widely distributed. Culture and molecular strain typing ofC. difficilerevealed that mice harbor ribotypes associated with human disease, and screening of kidney samples demonstrated genetic evidence of pathogenicLeptospiraspecies. In concert, these findings support the need for further research into the role of house mice as potential reservoirs for human pathogens and antimicrobial resistance in the built environment.IMPORTANCEMice are commensal pests often found in close proximity to humans, especially in urban centers. We surveyed mice from seven sites across New York City and found multiple pathogenic bacteria associated with febrile and gastrointestinal disease as well as an array of antimicrobial resistance genes.

Related Antimicrobial Resistance Genes Detected in Different Bacterial Species Co-isolated from Swine Fecal Samples

2011 ◽  
Vol 8 (6) ◽  
pp. 663-679 ◽  
Author(s):  
Jonathan G. Frye ◽  
Rebecca L. Lindsey ◽  
Richard J. Meinersmann ◽  
Mark E. Berrang ◽  
Charlene R. Jackson ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Bacterial Species ◽  
Fecal Samples ◽  
Antimicrobial Resistance Genes

scholarly journals Differential overlap in human and animal fecal microbiomes and resistomes in rural versus urban Bangladesh

2021 ◽  
Author(s):  
Jenna M Swarthout ◽  
Erica R Fuhrmeister ◽  
Latifah Hamzah ◽  
Angela Harris ◽  
Mir A. Ahmed ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Urban Communities ◽  
Resistance Genes ◽  
Low Income ◽  
Urban Areas ◽  
Pathogenic Bacteria ◽  
Small Scale ◽  
Rrna Gene ◽  
Antimicrobial Resistance Genes ◽  
Long Read

Background Low- and middle-income countries (LMICs) bear the largest mortality burden due to antimicrobial-resistant infections. Small-scale animal production and free-roaming domestic animals are common in many LMICs, yet data on zoonotic exchange of gut bacteria and antimicrobial resistance genes (ARGs) in low-income communities are sparse. Differences between rural and urban communities in population density, antibiotic use, and cohabitation with animals likely influence the frequency of transmission of gut bacterial communities and ARGs between humans and animals. Here, we determined the similarity in gut microbiomes, using 16S rRNA gene amplicon sequencing, and resistomes, using long-read metagenomics, between humans, chickens, and goats in rural compared to urban Bangladesh. Results Gut microbiomes were more similar between humans and chickens in rural (where cohabitation is more common) compared to urban areas, but there was no difference for humans and goats. Urbanicity did not impact the similarity of human and animal resistomes; however, ARG abundance was higher in urban animals compared to rural animals. We identified substantial overlap of ARG alleles in humans and animals in both settings. Humans and chickens had more overlapping ARG alleles than humans and goats. All fecal hosts carried ARGs on contigs classified as potentially pathogenic bacteria, including Escherichia coli, Campylobacter jejuni, Clostridiodes difficile, and Klebsiella pneumoniae. Conclusions While the development of antimicrobial resistance in animal gut microbiomes and subsequent transmission to humans has been demonstrated in intensive farming environments and high-income countries, evidence of zoonotic exchange of antimicrobial resistance in LMIC communities is lacking. This research provides genomic evidence of overlap of antimicrobial resistance genes between humans and animals, especially in urban communities, and highlights chickens as important reservoirs of antimicrobial resistance. Chicken and human gut microbiomes were more similar in rural Bangladesh, where cohabitation is more common. Incorporation of long-read metagenomics enabled characterization of bacterial hosts of resistance genes, which has not been possible in previous culture-independent studies using only short-read sequencing. These findings highlight the importance of developing strategies for combatting antimicrobial resistance that account for chickens being reservoirs of ARGs in community environments, especially in urban areas.

scholarly journals Metagenomic characterization of the effect of feed additives on the gut microbiome and antibiotic resistome of feedlot cattle

2017 ◽  
Author(s):  
Milton Thomas ◽  
Megan Webb ◽  
Sudeep Ghimire ◽  
Amanda Blair ◽  
Kenneth Olson ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Gut Microbiota ◽  
Resistance Genes ◽  
Feedlot Cattle ◽  
Feed Additives ◽  
Gastrointestinal Microbiota ◽  
Finishing Diets ◽  
Antimicrobial Resistance Genes ◽  
Metagenome Sequencing ◽  
The Impact

AbstractIn North America, antibiotic feed additives such as monensin and tylosin are added to the finishing diets of feedlot cattle to counter the ill-effects of feeding diets with rapidly digestible carbohydrates. While these feed additives have been proven to improve feed efficiency, and reduce liver abscess incidence, how these products impact the gastrointestinal microbiota is not completely understood. Furthermore, there are concerns that antibiotic feed additives may expand the antibiotic resistome of feedlot cattle by enriching antimicrobial resistance genes in pathogenic and nonpathogenic bacteria in the gut microbiota. In this study, we analyzed the impact of providing antibiotic feed additives to feedlot cattle using metagenome sequencing of treated and untreated animals. Our results indicate that use of antibiotic feed additives does not produce discernable changes at the phylum level however treated cattle had reduced the abundance of gram-positive bacteria at the genus level. The abundance of Ruminococcus, Erysipelotrichaceae and Lachanospira in the gut of treated steers was reduced. This may impact the ability of these animals to exclude pathogens from the gut. However, our results did not show any correlation between the presence of antimicrobial resistance genes in the gut microbiota and the administration of antibiotic feed additives.

scholarly journals Complete Genome Sequence of an mcr-10- Possessing Enterobacter roggenkampii Strain Isolated from a Dog in Japan

2021 ◽  
Vol 10 (30) ◽  
Author(s):  
Toyotaka Sato ◽  
Masaru Usui ◽  
Kazuki Harada ◽  
Yukari Fukushima ◽  
Chie Nakajima ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Genome Sequence ◽  
Resistance Genes ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Content Type ◽  
Antimicrobial Resistance Genes

The complete genome sequence of mcr-10 -possessing Enterobacter roggenkampii En37, isolated from a dog in Japan was determined. mcr-10 was located on a 70,277-bp IncFIB plasmid without any additional antimicrobial resistance genes.

scholarly journals Antimicrobial Resistance and Virulence Determination of Enterococcus spp. Obtained from Hospital Environment in Iran

2020 ◽  
Author(s):  
Saba Asgharzadeh Marghmalek ◽  
Reza Valadan ◽  
Mehrdad Gholami ◽  
Mohtaram Nasrolahei ◽  
Hamid Reza Goli
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Antibiotic Resistance Genes ◽  
Hospital Environment ◽  
Diffusion Method ◽  
Virulence Determinants ◽  
Environmental Isolates ◽  
Disk Diffusion Method ◽  
Antimicrobial Resistance Genes

Abstract Background: The role of the hospital environment as a source of pathogenic bacteria in recent studies has been poorly investigated. This study investigated the distribution of antimicrobial resistance genes and virulence determinants in Enterococcus species isolated from hospital environment in Sari, Iran. Method: Overall, 90 enterococci strains were obtained from high touch surfaces of four hospitals in Sari, Iran. These environmental samples were obtained from bathroom, beds, tables, doorknobs, room keys, wheelchair and walls in the patient and staff’s rooms. The resistance profile of the isolates was determined by disk diffusion method. Seven resistance genes and two virulence associated genes were evaluated molecularly by multiplex PCR. Results: According to the PCR, 42 (46.66%) of them were E. faecalis and 48 (53.33%) others were detected as E. faecium. Also, 28 (66.6%) E. faecalis and 18 (37.5%) E. faecium isolates were multidrug-resistant (MDR). Among all 90 environmental isolates 54 (60%), 54 (60%), 8 (8.8%), 8 (8.8%), 60 (66.6%), 26 (28.8%), and 24 (26.6%) isolates contained tetM, tetL, vanA, vanB, ermB, aac(6´)-Ie-aph(2´´)-Ia, and aph (3´)-IIIa, respectively. Moreover, all isolates were investigated for the presence of virulence genes and 88 (97.7%) of isolates had esp gene, and 16 (17.7%) had ace.Conclusions: This report showed that the environmental isolates of Enterococcus are the major sources of antibiotic resistance genes that can transfer them to the clinical isolates of bacteria in hospital settings. An effective following strategy should be organized to clearance and stop emergence of these pathogenic bacteria.

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