scholarly journals Distribution of β-Lactamase Genes in Clinical Isolates from California Central Valley Hospital Deviates from the United States Nationwide Trends

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 498
Author(s):  
Candace Guzman-Cole ◽  
Fabian Santiago ◽  
Sona Garsevanyan ◽  
Suzanne Sindi ◽  
Miriam Barlow

The evolution and dissemination of antibiotic resistance genes throughout the world are clearly affected by the selection and migration of resistant bacteria. However, the relative contributions of selection and migration at a local scale have not been fully explored. We sought to identify which of these factors has the strongest effect through comparisons of antibiotic resistance gene abundance between a distinct location and its surroundings over an extended period of six years. In this work, we used two repositories of extended spectrum β-lactamase (ESBL)-producing isolates collected since 2013 from patients at Dignity Health Mercy Medical Center (DHMMC) in Merced, California, USA, and a nationwide database compiled from clinical isolate genomes reported by the National Center for Biotechnology Information (NCBI) since 2013. We analyzed the stability of average resistance gene frequencies over the years since collection of these clinical isolates began for each repository. We then compared the frequencies of resistance genes in the DHMMC collection with the averages of the nationwide frequencies. We found DHMMC gene frequencies are stable over time and differ significantly from nationwide frequencies throughout the period of time we examined. Our results suggest that local selective pressures are a more important influence on the population structure of resistance genes in bacterial populations than migration. This, in turn, indicates the potential for antibiotic resistance to be controlled at a regional level, making it easier to limit the spread through local stewardship.

2019 ◽  
Vol 71 (2) ◽  
pp. 419-421
Author(s):  
Quentin Le Bastard ◽  
Pajau Vangay ◽  
Eric Batard ◽  
Dan Knights ◽  
Emmanuel Montassier

Abstract Little is known about the effect of human migration on gut microbiome antibiotic resistance gene (ARG) carriage. Using deep shotgun stool metagenomics analysis, we found a rapid increase in gut microbiome ARG richness and abundance in women from 2 independent ethnic groups relocating from Thailand to the United States.


2016 ◽  
Vol 62 (2) ◽  
pp. 353-359 ◽  
Author(s):  
G Terrance Walker ◽  
Tony J Rockweiler ◽  
Rossio K Kersey ◽  
Kelly L Frye ◽  
Susan R Mitchner ◽  
...  

Abstract BACKGROUND Multiantibiotic-resistant bacteria pose a threat to patients and place an economic burden on health care systems. Carbapenem-resistant bacilli and extended-spectrum β-lactamase (ESBL) producers drive the need to screen infected and colonized patients for patient management and infection control. METHODS We describe a multiplex microfluidic PCR test for perianal swab samples (Acuitas® MDRO Gene Test, OpGen) that detects the vancomycin-resistance gene vanA plus hundreds of gene subtypes from the carbapenemase and ESBL families Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-mediated metallo-β-lactamase (VIM), imipenemase metallo-β-lactamase (IMP), OXA-23, OXA-48, OXA-51, CTX-M-1, and CTX-M-2, regardless of the bacterial species harboring the antibiotic resistance. RESULTS Analytical test sensitivity per perianal swab is 11–250 CFU of bacteria harboring the antibiotic resistance genes. Test throughput is 182 samples per test run (1820 antibiotic resistance gene family results). We demonstrate reproducible test performance and 100% gene specificity for 265 clinical bacterial organisms harboring a variety of antibiotic resistance genes. CONCLUSIONS The Acuitas MDRO Gene Test is a sensitive, specific, and high-throughput test to screen colonized patients and diagnose infections for several antibiotic resistance genes directly from perianal swab samples, regardless of the bacterial species harboring the resistance genes.


2018 ◽  
Author(s):  
Karkman Antti ◽  
Pärnänen Katariina ◽  
Larsson D.G. Joakim

AbstractDischarge of treated sewage leads to release of antibiotic resistant bacteria, resistance genes and antibiotic residues to the environment. Such pollution can directly contribute to increased morbidity caused by the transmission of resistant fecal pathogens. Residual antibiotics in wastewaters have been speculated to select for resistant bacteria and thereby promote the evolution and emergence of new resistance factors. Increased abundance of antibiotic resistance genes in sewage and sewage-impacted environments may, however, simply be a result of fecal contamination with resistant bacteria rather than caused by an on-site selection pressure. In this study we have disentangled these two alternative scenarios by relating the relative resistance gene abundance to the accompanying extent of fecal pollution in publicly available metagenomic data. This was possible by analyzing the abundance of a newly discovered phage which is exceptionally abundant in, and specific to, human feces. The presence of resistance genes could largely be explained by fecal pollution, with no clear signs of selection in the environment, the only exception being environments polluted by very high levels of antibiotics from manufacturing where selection is evident. Our results demonstrate the necessity to take in to account the fecal pollution levels to avoid making erroneous assumptions regarding environmental selection of antibiotic resistance. The presence or absence of selection pressure has major implications for what the risk scenarios are (transmission versus evolution) and for what mitigations (reducing pathogenic bacteria or selective agents) should be prioritized to reduce health risks related to antibiotic resistance in the environment.


mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Christopher J. Harmer ◽  
Robert A. Moran ◽  
Ruth M. Hall

ABSTRACTThe insertion sequence IS26plays a key role in disseminating antibiotic resistance genes in Gram-negative bacteria, forming regions containing more than one antibiotic resistance gene that are flanked by and interspersed with copies of IS26. A model presented for a second mode of IS26movement that explains the structure of these regions involves a translocatable unit consisting of a unique DNA segment carrying an antibiotic resistance (or other) gene and a single IS copy. Structures resembling class I transposons are generated via RecA-independent incorporation of a translocatable unit next to a second IS26such that the ISs are in direct orientation. Repeating this process would lead to arrays of resistance genes with directly oriented copies of IS26at each end and between each unique segment. This model requires that IS26recognizes another IS26as a target, and in transposition experiments, the frequency of cointegrate formation was 60-fold higher when the target plasmid contained IS26. This reaction was conservative, with no additional IS26or target site duplication generated, and orientation specific as the IS26s in the cointegrates were always in the same orientation. Consequently, the cointegrates were identical to those formed via the known mode of IS26movement when a target IS26was not present. Intact transposase genes in both IS26s were required for high-frequency cointegrate formation as inactivation of either one reduced the frequency 30-fold. However, the IS26target specificity was retained. Conversion of each residue in the DDE motif of the Tnp26 transposase also reduced the cointegration frequency.IMPORTANCEResistance to antibiotics belonging to several of the different classes used to treat infections is a critical problem. Multiply antibiotic-resistant bacteria usually carry large regions containing several antibiotic resistance genes, and in Gram-negative bacteria, IS26is often seen in these clusters. A model to explain the unusual structure of regions containing multiple IS26copies, each associated with a resistance gene, was not available, and the mechanism of their formation was unexplored. IS26-flanked structures deceptively resemble class I transposons, but this work reveals that the features of IS26movement do not resemble those of the IS and class I transposons studied to date. IS26uses a novel movement mechanism that defines a new family of mobile genetic elements that we have called “translocatable units.” The IS26mechanism also explains the properties of IS257(IS431) and IS1216, which belong to the same IS family and mobilize resistance genes in Gram-positive staphylococci and enterococci.


2018 ◽  
Author(s):  
Vanessa R. Marcelino ◽  
Michelle Wille ◽  
Aeron C. Hurt ◽  
Daniel González-Acuña ◽  
Marcel Klaassen ◽  
...  

AbstractAntibiotic resistance is rendering common bacterial infections untreatable. Wildlife can incorporate and disperse antibiotic resistant bacteria in the environment, such as water systems, which in turn serve as reservoirs of resistance genes for human pathogens. We used bulk RNA-sequencing (meta-transcriptomics) to assess the diversity and expression levels of functionally active resistance genes in the microbiome of birds with aquatic behavior. We sampled birds across a range of habitats, from penguins in Antarctica to ducks in a wastewater treatment plant in Australia. This revealed 81 antibiotic resistance genes in birds from all localities, including β-lactam, tetracycline and chloramphenicol resistance in Antarctica, and genes typically associated with multidrug resistance plasmids in areas with high human impact. Notably, birds feeding at a wastewater treatment plant carried the greatest resistance gene burden, suggesting that human waste, even if it undergoes treatment, contributes to the spread of antibiotic resistance genes to the wild. Differences in resistance gene burden also reflected the birds’ ecology, taxonomic group and microbial functioning. Ducks, which feed by dabbling, carried a higher abundance and diversity of resistance genes than turnstones, avocets and penguins, that usually prey on more pristine waters. In sum, this study helps to reveal the complex factors explaining the distribution of resistance genes and their exchange routes between humans and wildlife.


2019 ◽  
Vol 13 (05) ◽  
pp. 426-433 ◽  
Author(s):  
Umama Khan ◽  
Sadia Afsana ◽  
Maria Kibtia ◽  
Mahboob Hossain ◽  
Naiyyum Choudhury ◽  
...  

Introduction: Although antibiotics have revolutionized health care by saving lives, the evolution of both pathogenic and commensal antibiotic-resistant bacteria are emerging as a threat in the health sector. As for Lactobacillus spp., it is usually a non-pathogenic bacteria. However, it can cause infection in immunocompromised condition. In this study, Lactobacillus spp. has been isolated from the faeces of infants with Hirschsprung disease (HD), which is congenital aganglionosis of intestine, where surgical approach and antibiotics are frequently used as medical intervention. The aim of this study is to assess the antibiotic resistance pattern and determine the presence of resistance genes, if any, in Lactobacillus spp. isolated from HD infants with ileostomy. Methodology: Six Lactobacillus spp. were isolated from faeces of six HD infants and confirmed using both conventional and molecular methods. Antibiotic resistance pattern was checked through disc diffusion method and was further investigated for the presence of antibiotic resistance genes (blaTEM, blaCTX-M, blaOXA-2, blaIMP, blaVIM-2, blaNDM-1 and mcr-1). Results: Antibiotic susceptibility of the isolates showed high level of resistance towards cephalosporins, oxacillin, aztreonam, meropenem and polymyxin group. However, four of the isolates showed the presence of blaCTX-M gene after PCR amplification. Conclusions: To our knowledge, this is the first report on the presence of antibiotic resistance gene blaCTX-M in Lactobacillus spp. and this presence may pose a serious threat in treatment regimen. As not much is known regarding the presence of blaCTX-M in Lactobacillus spp., this finding may provide new light to research on antibiotic resistance in gut microflora.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 230
Author(s):  
Shan Wan ◽  
Min Xia ◽  
Jie Tao ◽  
Yanjun Pang ◽  
Fugen Yu ◽  
...  

In this study, we used a metagenomic approach to analyze microbial communities, antibiotic resistance gene diversity, and human pathogenic bacterium composition in two typical landfills in China. Results showed that the phyla Proteobacteria, Bacteroidetes, and Actinobacteria were predominant in the two landfills, and archaea and fungi were also detected. The genera Methanoculleus, Lysobacter, and Pseudomonas were predominantly present in all samples. sul2, sul1, tetX, and adeF were the four most abundant antibiotic resistance genes. Sixty-nine bacterial pathogens were identified from the two landfills, with Klebsiella pneumoniae, Bordetella pertussis, Pseudomonas aeruginosa, and Bacillus cereus as the major pathogenic microorganisms, indicating the existence of potential environmental risk in landfills. In addition, KEGG pathway analysis indicated the presence of antibiotic resistance genes typically associated with human antibiotic resistance bacterial strains. These results provide insights into the risk of pathogens in landfills, which is important for controlling the potential secondary transmission of pathogens and reducing workers’ health risk during landfill excavation.


2012 ◽  
Vol 56 (9) ◽  
pp. 4703-4706 ◽  
Author(s):  
Jennifer L. Cottell ◽  
Mark A. Webber ◽  
Laura J. V. Piddock

ABSTRACTThe treatment of infections caused by antibiotic-resistant bacteria is one of the great challenges faced by clinicians in the 21st century. Antibiotic resistance genes are often transferred between bacteria by mobile genetic vectors called plasmids. It is commonly believed that removal of antibiotic pressure will reduce the numbers of antibiotic-resistant bacteria due to the perception that carriage of resistance imposes a fitness cost on the bacterium. This study investigated the ability of the plasmid pCT, a globally distributed plasmid that carries an extended-spectrum-β-lactamase (ESBL) resistance gene (blaCTX-M-14), to persist and disseminate in the absence of antibiotic pressure. We investigated key attributes in plasmid success, including conjugation frequencies, bacterial-host growth rates, ability to cause infection, and impact on the fitness of host strains. We also determined the contribution of theblaCTX-M-14gene itself to the biology of the plasmid and host bacterium. Carriage of pCT was found to impose no detectable fitness cost on various bacterial hosts. An absence of antibiotic pressure and inactivation of the antibiotic resistance gene also had no effect on plasmid persistence, conjugation frequency, or bacterial-host biology. In conclusion, plasmids such as pCT have evolved to impose little impact on host strains. Therefore, the persistence of antibiotic resistance genes and their vectors is to be expected in the absence of antibiotic selective pressure regardless of antibiotic stewardship. Other means to reduce plasmid stability are needed to prevent the persistence of these vectors and the antibiotic resistance genes they carry.


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