A new insight into the ARG association with antibiotics and non-antibiotic agents—antibiotic resistance and toxicity

ABSTRACTUnderstanding the distribution and mobility of antibiotic resistance genes (ARGs) in soil bacteria from diverse ecological niches is critical in assessing their impacts on the global spread of antibiotic resistance. In permafrost associated soils, climate and human driven forces augment near-surface thaw altering the overlying active layer. Physiochemical changes shift bacterial community composition and metabolic functioning, however, it is unknown if permafrost thaw will affect ARGs comprising the boreal soil resistome. To assess how thaw shifts the resistome, we performed susceptibility testing and whole genome sequencing on soil isolates from a disturbance-induced thaw gradient in Interior Alaska. We found resistance was widespread in the Alaskan isolates, with 87% of the 90 isolates resistant to at least one of the five antibiotics. We also observed positive trends in both the proportion of resistant isolates and the abundance of ARGs with permafrost thaw. However, the number of ARGs per genome and types of genes present were shown to cluster more strongly by bacterial taxa rather than thaw emphasizing the evolutionary origins of resistance and the role vertical gene transfer has in shaping the predominantly chromosomally encoded ARGs. The observed higher proportion of plasmid-borne and distinct ARGs in our isolates compared to RefSoil+ suggests local conditions affect the composition of the resistome along with selection for ARG mobility. Overall taxonomy and geography shape the resistome, suggesting that as microbial communities shift in response to permafrost thaw so will the ARGs in the boreal active layer.IMPORTANCEAs antibiotic resistance continues to emerge and rapidly spread in clinical settings, it is imperative to generate studies that build insight into the ecology of environmental resistance genes that pose a threat to human health. This study provides insight into the occurrence of diverse ARGs found in Alaskan soil bacteria which is suggestive of the potential to compromise health. The observed differences in ARG abundance with increasing permafrost thaw suggest the role of soil disturbance in driving the distribution of resistant determinants and the predominant taxa that shape the resistome. Moreover, the high-quality whole genome assemblies generated in this study are an extensive resource for microbial researchers interested in permafrost thaw and will provide a steppingstone for future research into ARG mobility and transmission risks.

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A survey of prevalence and phenotypic and genotypic assessment of antibiotic resistance in Staphylococcus aureus bacteria isolated from ready-to-eat food samples collected from Tehran Province, Iran

Tropical Medicine and Health ◽

10.1186/s41182-021-00366-4 ◽

2021 ◽

Vol 49 (1) ◽

Author(s):

Arash Mesbah ◽

Zohreh Mashak ◽

Zohreh Abdolmaleki

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Antibiotic Resistance Genes ◽

Food Samples ◽

Contamination Rate ◽

Biochemical Tests ◽

Antibiotic Resistance Profile ◽

Resistance To Penicillin ◽

Tehran Province ◽

Antibiotic Agents

Abstract Background Resistant Staphylococcus aureus (S. aureus) bacteria are considered among the major causes of foodborne diseases. This survey aims to assess genotypic and phenotypic profiles of antibiotic resistance in S. aureus bacteria isolated from ready-to-eat food samples. Methods According to the previously reported prevalence of S. aureus in ready-to-eat food samples, a total of 415 ready-to-eat food samples were collected from Tehran province, Iran. S. aureus bacteria were identified using culture and biochemical tests. Besides, the phenotypic antibiotic resistance profile was determined by disk diffusion. In addition, the genotypic pattern of antibiotic resistance was determined using the PCR. Results A total of 64 out of 415 (15.42%) ready-to-eat food samples were contaminated with S. aureus. Grilled mushrooms and salad olivieh harbored the highest contamination rate of (30%), while salami samples harbored the lowest contamination rate of 3.33%. In addition, S. aureus bacteria harbored the highest prevalence of resistance to penicillin (85.93%), tetracycline (85.93%), gentamicin (73.43%), erythromycin (53.12%), trimethoprim-sulfamethoxazole (51.56%), and ciprofloxacin (50%). However, all isolates were resistant to at least four antibiotic agents. Accordingly, the prevalence of tetK (70.31%), blaZ (64.06%), aacA-D (57.81%), gyrA (50%), and ermA (39.06%) was higher than that of other detected antibiotic resistance genes. Besides, AacA-D + blaZ (48.43%), tetK + blaZ (46.87%), aacA-D + tetK (39.06%), aacA-D + gyrA (20.31%), and ermA + blaZ (20.31%) were the most frequently identified combined genotypic patterns of antibiotic resistance. Conclusion Ready-to-eat food samples may be sources of resistant S. aureus, which pose a hygienic threat in case of their consumption. However, further investigations are required to identify additional epidemiological features of S. aureus in ready-to-eat foods.

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Division of Labor between SOS and PafBC in Mycobacterial DNA Repair and Mutagenesis

10.1101/2021.08.05.455301 ◽

2021 ◽

Author(s):

Oyindamola O Adefisayo ◽

Pierre Dupuy ◽

James M Bean ◽

Michael S Glickman

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Antibiotic Resistance ◽

Division Of Labor ◽

Transcriptional Regulatory Network ◽

Lexa Repressor ◽

Quinolone Antibiotics ◽

Transcriptional Regulatory ◽

Damage Response ◽

Insight Into

DNA repair systems allow microbes to survive in diverse environments that compromise chromosomal integrity. Pathogens such as M. tuberculosis must contend with the genotoxic host environment, which generates the mutations that underlie antibiotic resistance. Mycobacteria encode the widely distributed SOS pathway, governed by the LexA repressor, but also encode PafBC, a positive regulator of the transcriptional DNA damage response (DDR). Although the transcriptional outputs of these systems have been characterized, their full functional division of labor in survival and mutagenesis is unknown. Here we specifically ablate the PafBC or SOS pathways, alone and in combination, and test their relative contributions to repair. We find that SOS and PafBC have both distinct and overlapping roles that depend on the type of DNA damage. Most notably, we find that quinolone antibiotics and replication fork perturbation are inducers of the PafBC pathway, and that chromosomal mutagenesis is codependent on PafBC and SOS, through shared regulation of the DnaE2/ImuA/B mutasome. These studies define the complex transcriptional regulatory network of the DDR in mycobacteria and provide new insight into the regulatory mechanisms controlling the genesis of antibiotic resistance in M. tuberculosis.

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A global perspective of antibiotic-resistant Listeria monocytogenes prevalence in assorted ready to eat foods: A systematic review

Veterinary World ◽

10.14202/vetworld.2021.2219-2229 ◽

2021 ◽

pp. 2219-2229

Author(s):

Prudence Mpundu ◽

Allan Rabson Mbewe ◽

John Bwalya Muma ◽

Wizaso Mwasinga ◽

Nawa Mukumbuta ◽

...

Keyword(s):

Systematic Review ◽

Antibiotic Resistance ◽

Listeria Monocytogenes ◽

Meta Analysis ◽

Global Perspective ◽

Valuable Insight ◽

Resistance Profile ◽

Antibiotic Resistance Profile ◽

Pooled Prevalence ◽

Insight Into

Background and Aim: Listeria monocytogenes in ready-to-eat (RTE) foods remains consistently under-reported globally. Nevertheless, several independent studies conducted to investigate have elucidated the prevalence and antibiotic resistance profiles of L. monocytogenes in RTE-associated foods and their antibiotic resistance profiles. Given the rapid increase in consumption of RTE foods of both animal and plant origin, it is imperative to know the prevalence deductive data focusing on how much of L. monocytogenes is present in RTE foods, which is critical for food safety managers and retailers to assess the possible risk posed to end-users. In addition, valuable insight and another angle to the depth of the problem, we conducted a systematic review and meta-analysis to synthesize available data regarding the prevalence of L. monocytogenes in RTE foods and antibiotic resistance profiles. Materials and Methods: We conducted a meta-analysis study of L. monocytogenes and antibiotic resistance to clinically relevant antibiotics to determine the extent of L. monocytogenes contamination in RTE foods and antibiotic resistance profiles. The primary search terms, also known as keywords used, were restricted to peer-reviewed and review articles, and databases, including Google Scholars, Science-Direct, and Scopus, were searched. The inclusion of articles meeting eligibility criteria published between 2010 and 2020 after title, abstract, and full article screening. Data analysis was performed at multiple stages using quantitative meta-analysis reviews. Results: L. monocytogenes pooled proportion/prevalence was highest in chicken products determined at (22%) followed by various but uncategorized RTE foods at 21%. Regarding antibiotic resistance, profiling's highest pooled prevalence resistance was observed in penicillin at 80% resistance, followed by cephalosporin at 47%. Conclusion: Within its limitations, this study has attempted to provide insight into the pooled proportion/prevalence of L. monocytogenes in RTE foods and the antibiotic resistance profile at the global level. Determining the proportion/ prevalence of L. monocytogenes in RTE foods across the globe and antibiotic resistance profile is essential for providing quality food and reducing public health problems due to unsuccessful treatment of foodborne illness. This study provides insight into the pooled prevalence of L. monocytogenes in RTE foods and the antibiotic resistance profile. The results of this study partly endeavored to help appropriate authorities strengthen their preventive measures on specific RTE foods that are most likely to be contaminated with L. monocytogenes and antibiotic resistance profiles.

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Ribosome protection by antibiotic resistance ATP-binding cassette protein

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1803313115 ◽

2018 ◽

Vol 115 (20) ◽

pp. 5157-5162 ◽

Cited By ~ 26

Author(s):

Weixin Su ◽

Veerendra Kumar ◽

Yichen Ding ◽

Rya Ero ◽

Aida Serra ◽

...

Keyword(s):

Antibiotic Resistance ◽

Conformational Changes ◽

Atp Binding ◽

Peptidyl Transferase ◽

Exit Site ◽

Peptidyl Transferase Center ◽

Biochemical Assays ◽

Exit Tunnel ◽

Insight Into ◽

Atp Binding Cassette

The ribosome is one of the richest targets for antibiotics. Unfortunately, antibiotic resistance is an urgent issue in clinical practice. Several ATP-binding cassette family proteins confer resistance to ribosome-targeting antibiotics through a yet unknown mechanism. Among them, MsrE has been implicated in macrolide resistance. Here, we report the cryo-EM structure of ATP form MsrE bound to the ribosome. Unlike previously characterized ribosomal protection proteins, MsrE is shown to bind to ribosomal exit site. Our structure reveals that the domain linker forms a unique needle-like arrangement with two crossed helices connected by an extended loop projecting into the peptidyl-transferase center and the nascent peptide exit tunnel, where numerous antibiotics bind. In combination with biochemical assays, our structure provides insight into how MsrE binding leads to conformational changes, which results in the release of the drug. This mechanism appears to be universal for the ABC-F type ribosome protection proteins.

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