scholarly journals Withdrawal of Colistin Reduces Incidence of mcr-1-Harboring IncX4-Type Plasmids but Has Limited Effects on Unrelated Antibiotic Resistance

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1019
Author(s):  
Zunfang Tu ◽  
Ju Gu ◽  
Haoyu Zhang ◽  
Jinxin Liu ◽  
Junrui Shui ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Large Scale ◽  
Evolutionary Relationship ◽  
Antibiotic Resistance Genes ◽  
Feed Additive ◽  
Chinese Government ◽  
M Gene ◽  
High Genetic Diversity ◽  
Pig Farm ◽  
Relationship Of

The global dissemination of plasmid-mediated colistin resistance gene mcr and its variants have posed a great threat to public health. Therefore, the Chinese government banned the use of colistin as a feed additive in livestock in April 2017. To explore the dynamic changes of overall antibiotic resistance genes (ARGs) and phylogenetic relationship of bacteria from a single pig farm before and after the withdrawal of colistin, fecal swab samples were collected from a large-scale pig farm before (n = 32; 2 months pre-withdrawal of colistin) and after withdrawal of colistin (n = 30; 13 months post-withdrawal of colistin). Escherichia coli and Klebsiella pneumoniae were isolated. Whole-genome sequencing (Illumina, MiSeq) was performed to examine ARGs, plasmids and the genetic relationship of the isolates. The overall SNP results indicated all isolates had high genetic diversity, and the evolutionary relationship across isolates was not influenced by the ban of colistin. However, the prevalence of mcr-1.1 (5.6%, p < 0.01) was significantly lower than before the ban (86.4%). Plasmid profiling analysis showed that 17 of 20 (85.0%) observed mcr-1.1 genes reside on IncX4-type plasmids, 16 of which (94.1%) were from isolates before the ban. On the contrary, the presence of blaCTX-M gene was significantly increased (p = 0.0215) post-withdrawal of colistin. Our results showed that withdrawal of colistin reduced the incidence of mcr-1-harboring IncX4-type plasmids, but had limited influences on unrelated ARGs.

scholarly journals Emerging MDR-Pseudomonas aeruginosa in fish commonly harbor oprL and toxA virulence genes and blaTEM, blaCTX-M, and tetA antibiotic-resistance genes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdelazeem M. Algammal ◽  
Mahmoud Mabrok ◽  
Elayaraja Sivaramasamy ◽  
Fatma M. Youssef ◽  
Mona H. Atwa ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Antibiotic Resistance Genes ◽  
Health Concern ◽  
Diffusion Method ◽  
Multi Drug Resistance ◽  
Fish Farms ◽  
M Gene ◽  
Total Prevalence

Abstract This study aimed to investigate the prevalence, antibiogram of Pseudomonasaeruginosa (P.aeruginosa), and the distribution of virulence genes (oprL,exoS, phzM, and toxA) and the antibiotic-resistance genes (blaTEM, tetA, and blaCTX-M). A total of 285 fish (165 Oreochromisniloticus and 120 Clariasgariepinus) were collected randomly from private fish farms in Ismailia Governorate, Egypt. The collected specimens were examined bacteriologically. P. aeruginosa was isolated from 90 examined fish (31.57%), and the liver was the most prominent infected organ. The antibiogram of the isolated strains was determined using a disc diffusion method, where the tested strains exhibited multi-drug resistance (MDR) to amoxicillin, cefotaxime, tetracycline, and gentamicin. The PCR results revealed that all the examined strains harbored (oprL and toxA) virulence genes, while only 22.2% were positive for the phzM gene. On the contrary, none of the tested strains were positive for the exoS gene. Concerning the distribution of the antibiotic resistance genes, the examined strains harbored blaTEM, blaCTX-M, and tetA genes with a total prevalence of 83.3%, 77.7%, and 75.6%, respectively. Experimentally infected fish with P.aeruginosa displayed high mortalities in direct proportion to the encoded virulence genes and showed similar signs of septicemia found in the naturally infected one. In conclusion, P.aeruginosa is a major pathogen of O.niloticus and C.gariepinus.oprL and toxA genes are the most predominant virulence genes associated with P.aeruginosa infection. The blaCTX-M,blaTEM, and tetA genes are the main antibiotic-resistance genes that induce resistance patterns to cefotaxime, amoxicillin, and tetracycline, highlighting MDR P.aeruginosa strains of potential public health concern.

scholarly journals Coexistence of Antibiotic Resistance Genes and Virulence Factors Deciphered by Large-Scale Complete Genome Analysis

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Yu Pan ◽  
Jiaxiong Zeng ◽  
Liguan Li ◽  
Jintao Yang ◽  
Ziyun Tang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Large Scale ◽  
Antibiotic Resistance Genes ◽  
Comprehensive Analysis ◽  
Health Concern ◽  
Human Pathogens ◽  
Bacterial Genomes ◽  
Gene Acquisition

ABSTRACT Widespread use of antibiotics has enhanced the evolution of highly resilient pathogens and poses a severe risk to human health via coselection of antibiotic resistance genes (ARGs) and virulence factors (VFs). In this study, we rigorously evaluate the abundance relationship and physical linkage between ARGs and VFs by performing a comprehensive analysis of 9,070 bacterial genomes isolated from multiple species and hosts. The coexistence of ARGs and VFs was observed in bacteria across distinct phyla, pathogenicities, and habitats, especially among human-associated pathogens. The coexistence patterns of gene elements in different habitats and pathogenicity groups were similar, presumably due to frequent gene transfer. A shorter intergenic distance between mobile genetic elements and ARGs/VFs was detected in human/animal-associated bacteria, indicating a higher transfer potential. Increased accumulation of exogenous ARGs/VFs in human pathogens highlights the importance of gene acquisition in the evolution of human commensal bacteria. Overall, the findings provide insights into the genic features of combinations of ARG-VF and expand our understanding of ARG-VF coexistence in bacteria. IMPORTANCE Antibiotic resistance has become a serious global health concern. Despite numerous case studies, a comprehensive analysis of ARG and VF coexistence in bacteria is lacking. In this study, we explore the coexistence profiles of ARGs and VFs in diverse categories of bacteria by using a high-resolution bioinformatics approach. We also provide compelling evidence of unique ARG-VF gene pairs coexisting in specific bacterial genomes and reveal the potential risk associated with the coexistence of ARGs and VFs in organisms in both clinical settings and environments.

scholarly journals Intra- and Interspecies Conjugal Transfer of Tn916-Like Elements from Lactococcus lactis In Vitro and In Vivo

2009 ◽  
Vol 75 (19) ◽  
pp. 6352-6360 ◽  
Author(s):  
Joanna Boguslawska ◽  
Joanna Zycka-Krzesinska ◽  
Andrea Wilcks ◽  
Jacek Bardowski
Keyword(s):  
Antibiotic Resistance ◽  
Lactococcus Lactis ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Raw Milk ◽  
M Gene ◽  
Transfer Resistance

ABSTRACT Tetracycline-resistant Lactococcus lactis strains originally isolated from Polish raw milk were analyzed for the ability to transfer their antibiotic resistance genes in vitro, using filter mating experiments, and in vivo, using germfree rats. Four of six analyzed L. lactis isolates were able to transfer tetracycline resistance determinants in vitro to L. lactis Bu2-60, at frequencies ranging from 10−5 to 10−7 transconjugants per recipient. Three of these four strains could also transfer resistance in vitro to Enterococcus faecalis JH2-2, whereas no transfer to Bacillus subtilis YBE01, Pseudomonas putida KT2442, Agrobacterium tumefaciens UBAPF2, or Escherichia coli JE2571 was observed. Rats were initially inoculated with the recipient E. faecalis strain JH2-2, and after a week, the L. lactis IBB477 and IBB487 donor strains were introduced. The first transconjugants were detected in fecal samples 3 days after introduction of the donors. A subtherapeutic concentration of tetracycline did not have any significant effect on the number of transconjugants, but transconjugants were observed earlier in animals dosed with this antibiotic. Molecular analysis of in vivo transconjugants containing the tet(M) gene showed that this gene was identical to tet(M) localized on the conjugative transposon Tn916. Primer-specific PCR confirmed that the Tn916 transposon was complete in all analyzed transconjugants and donors. This is the first study showing in vivo transfer of a Tn916-like antibiotic resistance transposon from L. lactis to E. faecalis. These data suggest that in certain cases food lactococci might be involved in the spread of antibiotic resistance genes to other lactic acid bacteria.

scholarly journals Seasonal and spatial variability of antibiotic resistance genes and Class I integrons in the rivers of the Mekong delta, Vietnam

2021 ◽  
Author(s):  
Thi Thu Hang Pham ◽  
Khoa Dinh Hoang Dang ◽  
Emmanuelle Rohrbach ◽  
Florian Breider ◽  
Pierre Rossi
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Rainy Season ◽  
Large Scale ◽  
River Sediments ◽  
Mekong Delta ◽  
Antibiotic Resistance Genes ◽  
Dry Season ◽  
Class I ◽  
Economic Losses

Aquaculture activities are steadily expanding in Vietnam, covering an estimated 700,000 ha, with 89% of these culture ponds located in the Mekong Delta. Since 2009, large-scale bacterial epidemics have spread in response to this intensive cultivation. Antibiotics, even those considered as a last resort, have only partially mitigated this problem. In turn, the side effects of the massive use of these chemicals include the appearance of mobile genetic elements associated with antibiotic resistance genes (ARGs). The large-scale emergence of a diverse bacterial resistome, along with severe economic losses, has posed significant health risks to local residents. In this study, the seasonal and spatial distributions of the class I integrase (CL1) intl1 and the ARGs sul2 (sulfonamide), BLA-oxa1 (β-lactams), and ermB (erythromycin) were quantified from water and sediment samples collected during two consecutive seasons along the Vam Co River and its tributary (Long An province, Vietnam). The results showed that CL1 was present in all river compartments, reaching 2.98×104 copies/mL and 1.07×106 copies/g of sediment, respectively. The highest relative copy abundances to the 16S rDNA gene were measured in water samples, with up to 3.02% for BLA-oxa1, followed by sul2 (1.16%) and ermB (0.46%). Strong seasonal (dry season vs. rainy season) and spatial patterns were recorded for all resistance genes. Higher amounts of ARGs in river water could be associated with higher antibiotic use during the rainy season. In contrast, higher amounts of ARGs were recorded in river sediments during the dry season, making this habitat a potential reservoir of transient genes. Finally, the observations made in this study allowed us to clarify the environmental and anthropogenic influences that may favor the dispersal and persistence of ARGS in this riverine ecosystem.

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