scholarly journals Antimicrobial-resistance genes in the human gut prior the antibiotic-therapy era

Author(s):  
Tasha Santiago-Rodriguez

Antibiotic-resistance has long been associated with the use and abuse of antibiotics. However, increasing evidence is suggesting that antibiotic-resistance is in fact a phenomenon that has been occurring in natural environments for thousands and possibly millions of years. With the expansion of the microbiome field, it is now possible to characterize antibiotic-resistance genes altogether in different samples, including the human gut. This has also enabled the characterization of ancient human gut microbiomes, which also include antibiotic-resistance genes. Mummified gut remains represent a unique opportunity to characterize the microbiome and antibiotic-resistance genes prior the antibiotic-therapy era. Surprisingly, mummies from the Inca and Italian nobility cultures showed to possess antibiotic-resistance-like genes similar to modern-day antibiotic-resistance genes conferring resistance to beta-lactams, sulfa, quinolones and vancomycin, just to mention a few examples. This is intriguing as it further supports that antibiotic-resistance began in the environment and was transferred to the human gut by means that remain to be investigated and are a matter of ongoing speculation.

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4613 ◽  
Author(s):  
Yongda Zhao ◽  
Lili Guo ◽  
Jie Li ◽  
Xianhui Huang ◽  
Binghu Fang

BackgroundHaemophilus parasuisis a common porcine respiratory pathogen that causes high rates of morbidity and mortality in farmed swine. We performed a molecular characterization of antimicrobial resistance genes harbored byH. parasuisfrom pig farms in China.MethodsWe screened 143H. parasuisisolates for antimicrobial susceptibility against six fluoroquinolone antibiotics testing by the broth microdilution method, and the presence of 64 antimicrobial resistance genes by PCR amplification and DNA sequence analysis. We determined quinolone resistance determining region mutations of DNA gyrase (gyrAandgyrB) and topoisomerase IV (parCandparE). The genetic relatedness among the strains was analyzed by pulsed-field gel electrophoresis.ResultsSusceptibility test showed that all isolates were low resistance to lomefloxacin (28.67%), levofloxacin (20.28%), norfloxacin (22.38%), ciprofloxacin (23.78%), however, high resistance levels were found to nalidixic acid (82.52%) and enrofloxacin (55.94%). In addition, we found 14 antimicrobial resistance genes were present in these isolates, includingblaTEM-1, blaROB-1,ermB, ermA, flor, catl, tetB, tetC, rmtB, rmtD, aadA1, aac(3′)-llc, sul1, and sul2genes. Interestingly, one isolate carried five antibiotic resistance genes (tetB, tetC, flor, rmtB, sul1). The genestetB,rmtB,andflorwere the most prevalent resistance genes inH. parasuisin China. Alterations in thegyrAgene (S83F/Y, D87Y/N/H/G) were detected in 81% of the strains andparCmutations were often accompanied by agyrAmutation. Pulsed-field gel electrophoresis typing revealed 51 unique patterns in the isolates carrying high-level antibiotic resistance genes, indicating considerable genetic diversity and suggesting that the genes were spread horizontally.DiscussionThe current study demonstrated that the high antibiotic resistance ofH. parasuisin piglets is a combination of transferable antibiotic resistance genes and multiple target gene mutations. These data provide novel insights for the better understanding of the prevalence and epidemiology of antimicrobial resistance inH. parasuis.


2017 ◽  
Author(s):  
Yongda Zhao ◽  
Lili Guo ◽  
Jie Li ◽  
Xianhui Huang ◽  
Binghu Fang

Background: Haemophilus parasuis is a common porcine respiratory disease that causes high rates of morbidity and mortality in farmed swine. We performed a molecular characterization of antimicrobial resistance genes harbored by H. parasuis from pig farms in China. Methods: We screened 143 H. parasuis isolates for the presence of 64 antimicrobial resistance genes by PCR amplification and DNA sequence analysis. We determined quinolone resistance determining region mutations of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE). The genetic relatedness among the strains was analyzed by pulsed-field gel electrophoresis. Results: We found 14 antimicrobial resistance genes were present in these isolates, including TEM-1, ROB-1.ermB,ermA ,flor, catl,tetB,tetC, rmtB, rmtD, aadA1, aac(3’)-ⅡC, sul1, and sul2 genes. Interestingly, one isolate carried 5 antibiotic resistance genes (tetB, tetC, flor, rmtB, sul1). The genes tetB, rmtB, and flor were the most prevalent resistance genes in H. parasuis in China. Alterations in the gyrA gene (S83F/Y, D87Y/N/H/G) were detected in 81% of the strains and parC mutations were often accompanied by a gyrA mutation. pulsed-field gel electrophoresis typing revealed 51 unique patterns in the isolates carrying antibiotic resistance genes indicating considerable genetic diversity and suggesting the genes were spread horizontally. Discussion: The current study demonstrated that the high antibiotic resistance of H. parasuis in piglets is a combination of transferable antibiotic resistance genes and multiple target gene mutations. GyrA gene mutation also was the most important role in quinolone resistance. These data provide novel insights for the better understanding of the prevalence and epidemiology of antimicrobial resistance in H. parasuis.


2017 ◽  
Author(s):  
Yongda Zhao ◽  
Lili Guo ◽  
Jie Li ◽  
Xianhui Huang ◽  
Binghu Fang

Background: Haemophilus parasuis is a common porcine respiratory disease that causes high rates of morbidity and mortality in farmed swine. We performed a molecular characterization of antimicrobial resistance genes harbored by H. parasuis from pig farms in China. Methods: We screened 143 H. parasuis isolates for the presence of 64 antimicrobial resistance genes by PCR amplification and DNA sequence analysis. We determined quinolone resistance determining region mutations of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE). The genetic relatedness among the strains was analyzed by pulsed-field gel electrophoresis. Results: We found 14 antimicrobial resistance genes were present in these isolates, including TEM-1, ROB-1.ermB,ermA ,flor, catl,tetB,tetC, rmtB, rmtD, aadA1, aac(3’)-ⅡC, sul1, and sul2 genes. Interestingly, one isolate carried 5 antibiotic resistance genes (tetB, tetC, flor, rmtB, sul1). The genes tetB, rmtB, and flor were the most prevalent resistance genes in H. parasuis in China. Alterations in the gyrA gene (S83F/Y, D87Y/N/H/G) were detected in 81% of the strains and parC mutations were often accompanied by a gyrA mutation. pulsed-field gel electrophoresis typing revealed 51 unique patterns in the isolates carrying antibiotic resistance genes indicating considerable genetic diversity and suggesting the genes were spread horizontally. Discussion: The current study demonstrated that the high antibiotic resistance of H. parasuis in piglets is a combination of transferable antibiotic resistance genes and multiple target gene mutations. GyrA gene mutation also was the most important role in quinolone resistance. These data provide novel insights for the better understanding of the prevalence and epidemiology of antimicrobial resistance in H. parasuis.


Author(s):  
Samantha Reddy ◽  
Oliver T. Zishiri

Campylobacter spp. are common pathogenic bacteria in both veterinary and human medicine. Infections caused by Campylobacter spp. are usually treated using antibiotics. However, the injudicious use of antibiotics has been proven to spearhead the emergence of antibiotic resistance. The purpose of this study was to detect the prevalence of antibiotic resistance genes in Campylobacter spp. isolated from chickens and human clinical cases in South Africa. One hundred and sixty one isolates of Campylobacter jejuni and Campylobacter coli were collected from chickens and human clinical cases and then screened for the presence of antimicrobial resistance genes. We observed a wide distribution of the tetO gene, which confers resistance to tetracycline. The gyrA genes that are responsible quinolone resistance were also detected. Finally, our study also detected the presence of the blaOXA-61, which is associated with ampicillin resistance. There was a higher (p < 0.05) prevalence of the studied antimicrobial resistance genes in chicken faeces compared with human clinical isolates. The tetO gene was the most prevalent gene detected, which was isolated at 64% and 68% from human and chicken isolates, respectively. The presence of gyrA genes was significantly (p < 0.05) associated with quinolone resistance. In conclusion, this study demonstrated the presence of gyrA (235 bp), gyrA (270 bp), blaOXA-61 and tetO antimicrobial resistance genes in C. jejuni and C. coli isolated from chickens and human clinical cases. This indicates that Campylobacter spp. have the potential of resistance to a number of antibiotic classes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wenxiu Ai ◽  
Ying Zhou ◽  
Bingjie Wang ◽  
Qing Zhan ◽  
Longhua Hu ◽  
...  

Many antimicrobial resistance genes usually located on transferable plasmids are responsible for multiple antimicrobial resistance among multidrug-resistant (MDR) Gram-negative bacteria. The aim of this study is to characterize a carbapenemase-producing Enterobacter hormaechei 1575 isolate from the blood sample in a tertiary hospital in Wuhan, Hubei Province, China. Antimicrobial susceptibility test showed that 1575 was an MDR isolate. The whole genome sequencing (WGS) and comparative genomics were used to deeply analyze the molecular information of the 1575 and to explore the location and structure of antibiotic resistance genes. The three key resistance genes (blaSFO–1, blaNDM–1, and mcr-9) were verified by PCR, and the amplicons were subsequently sequenced. Moreover, the conjugation assay was also performed to determine the transferability of those resistance genes. Plasmid files were determined by the S1 nuclease pulsed-field gel electrophoresis (S1-PFGE). WGS revealed that p1575-1 plasmid was a conjugative plasmid that possessed the rare coexistence of blaSFO–1, blaNDM–1, and mcr-9 genes and complete conjugative systems. And p1575-1 belonged to the plasmid incompatibility group IncHI2 and multilocus sequence typing ST102. Meanwhile, the pMLST type of p1575-1 was IncHI2-ST1. Conjugation assay proved that the MDR p1575-1 plasmid could be transferred to other recipients. S1-PFGE confirmed the location of plasmid with molecular weight of 342,447 bp. All these three resistant genes were flanked by various mobile elements, indicating that the blaSFO–1, blaNDM–1, and mcr-9 could be transferred not only by the p1575-1 plasmid but also by these mobile elements. Taken together, we report for the first time the coexistence of blaSFO–1, blaNDM–1, and mcr-9 on a transferable plasmid in a MDR clinical isolate E. hormaechei, which indicates the possibility of horizontal transfer of antibiotic resistance genes.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mobin Rezanejad ◽  
Sepideh Karimi ◽  
Hassan Momtaz

Abstract Background Trueperella pyogenes is one of the most clinically imperative bacteria responsible for severe cases of mastitis and metritis, particularly in postpartum dairy cows. The bacterium has emergence of antibiotic resistance and virulence characters. The existing research was done to apprise the phenotypic and genotypic evaluation of antibiotic resistance and characterization of virulence factors in the T. pyogenes bacteria of bovine mastitis and metritis in postpartum cows. Methods Two-hundred and twenty-six bovine mastitic milk and 172 uterine swabs were collected and transferred to laboratory. Samples were cultured and T. pyogenes isolates were subjected to disk diffusion and DNA extraction. Distribution of virulence and antibiotic resistance genes was studied by PCR. Results Thirty-two out of 226 (14.15%) mastitic milk and forty-one out of 172 (23.83%) uterine swab samples were positive for T. pyogenes. Isolates of mastitic milk harbored the highest prevalence of resistance toward gentamicin (100%), penicillin (100%), ampicillin (90.62%), amoxicillin (87.50%) and trimethoprim-sulfamethoxazole (87.50%), while those of metritis harbored the highest prevalence of resistance toward ampicillin (100%), amoxicillin (100%), gentamicin (97.56%), penicillin (97.56%) and cefalexin (97.56%). AacC, aadA1, aadA2 and tetW were the most generally perceived antibiotic resistance genes. All bacteria harbored plo (100%) and fimA (100%) virulence factors. NanP, nanH, fimC and fimE were also the most generally perceived virulence factors. Conclusions All bacteria harbored plo and fimA virulence factors which showed that they can use as specific genetic markers with their important roles in pathogenicity of T. pyogenes bacteria. Phenotypic pattern of antibiotic resistance was confirmed by genotypic characterization of antibiotic resistance genes.


Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
Adam Baraka ◽  
German M. Traglia ◽  
Sabrina Montaña ◽  
Marcelo E. Tolmasky ◽  
Maria Soledad Ramirez

Acinetobacter non-baumannii species are becoming common etiologic agents of nosocomial infections. Furthermore, clinical isolates belonging to this group of bacteria are usually resistant to one or more antibiotics. The current information about antibiotic resistance genes in the different A. non-baumannii species has not yet been studied as a whole. Therefore, we did a comparative study of the resistomes of A. non-baumannii pathogens based on information available in published articles and genome sequences. We searched the available literature and sequences deposited in GenBank to identify the resistance gene content of A. calcoaceticus, A. lwoffii, A. junii, A. soli, A. ursingii, A. bereziniae, A. nosocomialis, A. portensis, A. guerrae, A. baylyi, A. calcoaceticus, A. disperses, A. johnsonii, A. junii, A. lwoffii, A. nosocomialis, A. oleivorans, A. oryzae, A. pittii, A. radioresistens, and A. venetianus. The most common genes were those coding for different β-lactamases, including the carbapenemase genes blaNDM-1 and blaOXA-58. A. pittii was the species with the most β-lactamase resistance genes reported. Other genes that were commonly found include those encoding some aminoglycoside modifying enzymes, the most common being aph(6)-Id, ant(3″)-IIa, and aph(3″)-Ib, and efflux pumps. All or part of the genes coding for the AdeABC, AdeFGH, and AdeIJK efflux pumps were the most commonly found. This article incorporates all the current information about A. non-baumannii resistance genes. The comparison of the different resistomes shows that there are similarities in the genes present, but there are also significant differences that could impact the efficiency of treatments depending on the etiologic agent. This article is a comprehensive resource about A. non-baumannii resistomes.


2019 ◽  
Vol 63 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Ewelina Pyzik ◽  
Agnieszka Marek ◽  
Dagmara Stępień-Pyśniak ◽  
Renata Urban-Chmiel ◽  
Łukasz S. Jarosz ◽  
...  

AbstractIntroduction:The study sought to characterise antimicrobial resistance among coagulase-negativeStaphylococcus(CNS) species recovered from broiler chickens and turkeys in Poland including the presence of 12 antimicrobial resistance genes and five classical genes of staphylococcal enterotoxins.Material and Methods:A panel of 11 antimicrobial disks evaluated the phenotypic sensitivity of the tested strains to antibiotics. Five multiplex PCR assays were performed using primer pairs for specific detection of antibiotic resistance genes and staphylococcal enterotoxin A to E genes.Results:Selected antimicrobial agent susceptibility testing revealed 100% of such inin vitroconditions to cefoxitin among strains ofStaphylococcus sciuriandS. chromogenes. TheblaZ (for ß-lactam) andmecA (for methicillin resistance) genes were in 58.3% and 27.5% of strains, respectively. Among genes resistant to tetracyclines,tetK was most frequent. Fewer (CNS) strains showed genes resistant to macrolides, lincosamides, and florfenicol/chloramphenicol. Multiplex PCR for classical enterotoxins (A-E) detected theseegene in twoS. hominisstrains, while thesebgene producing enterotoxin B was found in one strain ofS. epidermidis.Conclusion:CNS strains ofStaphylococcusisolated from poultry were either phenotypically or genotypically multidrug resistant. Testing for the presence of the five classical enterotoxin genes showed that CNS strains, as in the case ofS. aureusstrains, can be a source of food intoxications.


2010 ◽  
Vol 8 (4) ◽  
pp. 251-259 ◽  
Author(s):  
Heather K. Allen ◽  
Justin Donato ◽  
Helena Huimi Wang ◽  
Karen A. Cloud-Hansen ◽  
Julian Davies ◽  
...  

2013 ◽  
Vol 80 (4) ◽  
pp. 1482-1488 ◽  
Author(s):  
Jing Yang ◽  
Chao Wang ◽  
Jinyu Wu ◽  
Li Liu ◽  
Gang Zhang ◽  
...  

ABSTRACTThe genusExiguobacteriumcan adapt readily to, and survive in, diverse environments. Our study demonstrated thatExiguobacteriumsp. strain S3-2, isolated from marine sediment, is resistant to five antibiotics. The plasmid pMC1 in this strain carries seven putative resistance genes. We functionally characterized these resistance genes inEscherichia coli, and genes encoding dihydrofolate reductase and macrolide phosphotransferase were considered novel resistance genes based on their low similarities to known resistance genes. The plasmid G+C content distribution was highly heterogeneous. Only the G+C content of one block, which shared significant similarity with a plasmid fromExiguobacterium arabatum, fit well with the mean G+C content of the host. The remainder of the plasmid was composed of mobile elements with a markedly lower G+C ratio than the host. Interestingly, five mobile elements located on pMC1 showed significant similarities to sequences found in pathogens. Our data provided an example of the link between resistance genes in strains from the environment and the clinic and revealed the aggregation of antibiotic resistance genes in bacteria isolated from fish farms.


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