scholarly journals Decreased Antibiotic Susceptibility in Pseudomonas aeruginosa Surviving UV Irradition

2021 ◽  
Vol 12 ◽  
Author(s):  
Hai-bei Li ◽  
Ai-ming Hou ◽  
Tian-jiao Chen ◽  
Dong Yang ◽  
Zheng-shan Chen ◽  
...  

Given its excellent performance against the pathogens, UV disinfection has been applied broadly in different fields. However, only limited studies have comprehensively investigated the response of bacteria surviving UV irradiation to the environmental antibiotic stress. Here, we investigated the antibiotic susceptibility of Pseudomonas aeruginosa suffering from the UV irradiation. Our results revealed that UV exposure may decrease the susceptibility to tetracycline, ciprofloxacin, and polymyxin B in the survival P. aeruginosa. Mechanistically, UV exposure causes oxidative stress in P. aeruginosa and consequently induces dysregulation of genes contributed to the related antibiotic resistance genes. These results revealed that the insufficient ultraviolet radiation dose may result in the decreased antibiotic susceptibility in the pathogens, thus posing potential threats to the environment and human health.

2018 ◽  
Vol 4 (12) ◽  
pp. 2051-2057 ◽  
Author(s):  
Fuzheng Zhao ◽  
Qing Hu ◽  
Hongqiang Ren ◽  
Xu-Xiang Zhang

UV irradiation disturbs the regulatory system of efflux pump proteins to sensitize P. aeruginosa to multiple antibiotics. The increasing susceptibility to rifampicin and vancomycin might be caused by UV-mediated mutations in antibiotic resistance genes.


Author(s):  
Cláudia A. Ribeiro ◽  
Luke A. Rahman ◽  
Louis G. Holmes ◽  
Ayrianna M. Woody ◽  
Calum M. Webster ◽  
...  

AbstractThe spread of multidrug-resistance in Gram-negative bacterial pathogens presents a major clinical challenge, and new approaches are required to combat these organisms. Nitric oxide (NO) is a well-known antimicrobial that is produced by the immune system in response to infection, and numerous studies have demonstrated that NO is a respiratory inhibitor with both bacteriostatic and bactericidal properties. However, given that loss of aerobic respiratory complexes is known to diminish antibiotic efficacy, it was hypothesised that the potent respiratory inhibitor NO would elicit similar effects. Indeed, the current work demonstrates that pre-exposure to NO-releasers elicits a > tenfold increase in IC50 for gentamicin against pathogenic E. coli (i.e. a huge decrease in lethality). It was therefore hypothesised that hyper-sensitivity to NO may have arisen in bacterial pathogens and that this trait could promote the acquisition of antibiotic-resistance mechanisms through enabling cells to persist in the presence of toxic levels of antibiotic. To test this hypothesis, genomics and microbiological approaches were used to screen a collection of E. coli clinical isolates for antibiotic susceptibility and NO tolerance, although the data did not support a correlation between increased carriage of antibiotic resistance genes and NO tolerance. However, the current work has important implications for how antibiotic susceptibility might be measured in future (i.e. ± NO) and underlines the evolutionary advantage for bacterial pathogens to maintain tolerance to toxic levels of NO.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 930
Author(s):  
Delia Gambino ◽  
Sonia Sciortino ◽  
Sergio Migliore ◽  
Lucia Galuppo ◽  
Roberto Puleio ◽  
...  

The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (blaTEM, blaOXA, tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.


2021 ◽  
Author(s):  
Fernando Sanz-García ◽  
Sara Hernando-Amado ◽  
José Luis Martínez

ABSTRACTBACKGROUNDAntibiotic pollution of non-clinical environments might have a relevant impact on human health if resistant pathogens are selected. However, this potential risk is often overlooked, since drug concentrations in nature are usually below their minimal inhibitory concentrations (MICs). Albeit, antibiotic resistant bacteria can be selected even at sub-MIC concentrations, in a range that is dubbed the sub-MIC selective window, which depends on both the antibiotic and the pathogen.OBJECTIVESDetermine the sub-MIC selective windows of seven antibiotics of clinical relevance in the opportunistic pathogen Pseudomonas aeruginosa and evaluate the risk for selecting resistant mutants in nature, based on published data about the amount of antimicrobials detected in natural environments.METHODSWe conducted evolution experiments of P. aeruginosa PA14 in presence of sub-MIC concentrations of ceftazidime, amikacin, levofloxacin, ciprofloxacin, tetracycline, polymyxin B or imipenem, and measured drug susceptibility of the evolved populations.RESULTSSub-MIC selective window of quinolones was the largest, and the ones of polymyxin B and imipenem, the narrowest. Clinically relevant multidrug resistant (MDR) mutants (presenting MICs above EUCAST clinical breakpoints) arose within the sub-MIC selective windows of the majority of antibiotics tested, being these phenotypes probably mediated by efflux pumps′ activity.DISCUSSIONOur data show that the concentration of antibiotics reported in aquatic ecosystems -colonizable by P. aeruginosa- are, in occasions, higher than the ones able to select MDR mutants. This finding has implications for understanding the role of different ecosystems and conditions in the emergence of antibiotic resistance from a One-Health point of view. Further, it highlights the importance of delineating the sub-MIC selective windows for drugs of clinical value in pathogens with environmental niches, in order to evaluate the health risks due to antibiotic pollution of natural ecosystems and ultimately tackle antibiotic resistance.


Author(s):  
Sanjana Mukherjee ◽  
Heather M. Blankenship ◽  
Jose A. Rodrigues ◽  
Rebekah E. Mosci ◽  
James T. Rudrik ◽  
...  

Background: Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that contributes to over 250,000 infections in the US each year. Because antibiotics are not recommended for STEC infections, resistance in STEC has not been widely researched despite an increased likelihood for the transfer of resistance gene from STEC to opportunistic pathogens residing within the same microbial community. Methods: Between 2001 and 2014, 969 STEC isolates were collected from Michigan patients. Serotyping and antibiotic susceptibility profiles to clinically relevant antibiotics were determined using disc diffusion, while epidemiological data was used to identify factors associated with resistance. Whole genome sequencing was used to examine genetic relatedness and identify genetic determinants and mechanisms of resistance in the non-O157 isolates. Results: Increasing frequencies of resistance to at least one antibiotic was observed over the 14 years (p=0.01). While the non-O157 serogroups were more commonly resistant than O157 (Odds Ratio: 2.4; 95% Confidence Interval:1.43-4.05), the frequency of ampicillin resistance among O157 isolates was significantly higher in Michigan compared to the national average (p=0.03). Genomic analysis of 321 non-O157 isolates uncovered 32 distinct antibiotic resistance genes (ARGs). Although mutations in genes encoding resistance to ciprofloxacin and ampicillin were detected in four isolates, most of the horizontally acquired ARGs conferred resistance to aminoglycosides, β-lactams, sulfonamides and/or tetracycline. Conclusions: This study provides insight into the mechanisms of resistance in a large collection of clinical non-O157 STEC isolates and demonstrates that antibiotic resistance among all STEC serogroups has increased over time, prompting the need for enhanced surveillance.


2019 ◽  
Vol 64 (3) ◽  
Author(s):  
Shannon R. Coleman ◽  
Travis Blimkie ◽  
Reza Falsafi ◽  
Robert E. W. Hancock

ABSTRACT Swarming surface motility is a complex adaptation leading to multidrug antibiotic resistance and virulence factor production in Pseudomonas aeruginosa. Here, we expanded previous studies to demonstrate that under swarming conditions, P. aeruginosa PA14 is more resistant to multiple antibiotics, including aminoglycosides, β-lactams, chloramphenicol, ciprofloxacin, tetracycline, trimethoprim, and macrolides, than swimming cells, but is not more resistant to polymyxin B. We investigated the mechanism(s) of swarming-mediated antibiotic resistance by examining the transcriptomes of swarming cells and swarming cells treated with tobramycin by transcriptomics (RNA-Seq) and reverse transcriptase quantitative PCR (qRT-PCR). RNA-Seq of swarming cells (versus swimming) revealed 1,581 dysregulated genes, including 104 transcriptional regulators, two-component systems, and sigma factors, numerous upregulated virulence and iron acquisition factors, and downregulated ribosomal genes. Strain PA14 mutants in resistome genes that were dysregulated under swarming conditions were tested for their ability to swarm in the presence of tobramycin. In total, 41 mutants in genes dysregulated under swarming conditions were shown to be more resistant to tobramycin under swarming conditions, indicating that swarming-mediated tobramycin resistance was multideterminant. Focusing on two genes downregulated under swarming conditions, both prtN and wbpW mutants were more resistant to tobramycin, while the prtN mutant was additionally resistant to trimethoprim under swarming conditions; complementation of these mutants restored susceptibility. RNA-Seq of swarming cells treated with subinhibitory concentrations of tobramycin revealed the upregulation of the multidrug efflux pump MexXY and downregulation of virulence factors.


2013 ◽  
Vol 67 (5) ◽  
pp. 1144-1149 ◽  
Author(s):  
Maria Olívia Zanetti ◽  
Vinicius Vicente Martins ◽  
André Pitondo-Silva ◽  
Eliana Guedes Stehling

Pseudomonas aeruginosa is an important nosocomial pathogen also found in water, soil, plants and in human and animal fecal samples. In this study, 31 isolates from water samples were analyzed by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and PCR to detect integrons and investigated for antibiotic resistance and plasmidial profile. The results demonstrated the presence of plasmids in four isolates. Three of these, isolates from water in a city park (Curupira Park, Ribeirão Preto, Brazil) and a lake at the University of São Paulo (Campus of Ribeirão Preto), had plasmids with the same molecular weight (21MDa) and similar resistance profiles, although they were shown to be genetically different by ERIC-PCR. Class 1 and class 2 integrons were detected in one of these isolates. The results suggest that environmental P. aeruginosa strains may be a potential reservoir of plasmids and antibiotic resistance genes.


2016 ◽  
Vol 4 (1) ◽  
Author(s):  
M. B. Couger ◽  
Anna Wright ◽  
Erika I. Lutter ◽  
Noha Youssef

We report here the draft genome sequences of five Pseudomonas aeruginosa isolates obtained from sputum samples from two cystic fibrosis patients with chronic colonization. These closely related strains harbor 225 to 493 genes absent from the P. aeruginosa POA1 genome and contain 178 to 179 virulence factors and 29 to 31 antibiotic resistance genes.


2018 ◽  
Author(s):  
Prasanth Manohar ◽  
Thamaraiselvan Shanthini ◽  
Reethu Ann Philip ◽  
Subramani Ramkumar ◽  
Manali Kale ◽  
...  

AbstractTo evaluate the presence of biofilm-specific antibiotic-resistant genes, PA0756-0757, PA5033 and PA2070 in Pseudomonas aeruginosa isolated from clinical samples in Tamil Nadu. For this cross-sectional study, 24 clinical isolates (included pus, urine, wound, and blood) were collected from two diagnostic centers in Chennai from May 2015 to February 2016. Biofilm formation was assessed using microtiter dish biofilm formation assay and minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) were determined for planktonic and biofilm cells (MBC assay). Further, PCR amplification of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033 and PA2070 were performed. Biofilm formation was found to be moderate/strong in 16 strains. MBC for planktonic cells showed that 4, 7, 10 and 14 strains were susceptible to gentamicin, ciprofloxacin, meropenem and colistin respectively. In MBC assay for biofilm cells (MBC-B), all the 16 biofilm producing strains were resistant to ciprofloxacin and gentamicin whereas nine and four were resistant to meropenem, and colistin respectively. The biofilm-specific antibiotic-resistant genes PA0756-0757 was found in 10 strains, 6 strains with PA5033 and 9 strains with PA2070 that were found to be resistant phenotypically. This study highlighted the importance of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033, and PA2070 in biofilm-forming P. aeruginosa.


2021 ◽  
Vol 10 (1) ◽  
pp. 40-48
Author(s):  
O.C. Adekunle ◽  
A. Mustapha ◽  
G. Odewale ◽  
R.O. Ojedele

Introduction: Pseudomonas aeruginosa (P. aeruginosa) is a frequent nosocomial pathogen that causes severe diseases in many clinical and community settings. The objectives were to investigate the occurrence of multiple antibiotic resistant P. aeruginosa strains among clinical samples and to detect the presence of antibiotic resistance genes in the DNA molecules of the strains.Methods: Clinical specimens were collected aseptically from various human anatomical sites in five selected health institutions within Kwara State, Nigeria. Multiple drug resistance patterns of isolated micro-organisms to different antibiotics were determined using the Bauer Kirby disc diffusion technique. The DNA samples of the multiple resistant P. aeruginosa strains were extracted and subjected to Polymerase Chain Reaction (PCR) for resistance gene determination.Results: A total of 145 isolates were identified as P. aeruginosa from the clinical samples. Absolute resistance to ceftazidime, gentamicin and ceftriaxone was observed while low resistance to ciprofloxacin, piperacillin and imipenem was documented. The prevalence of bla VIM , ,bla CTX-M and blaTEM were 34.4 %, 46.7 % and 16.7 % respectively.Conclusion: This study has shown that there is a high occurrence of metallo â-lactamase- producing and antibiotic-resistant strains of P. aeruginosa in clinical specimens from the studied area. Keywords: Metallo â-lactamase enzyme, P. aeruginosa, clinical samples, antibiotic-resistance genes


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