scholarly journals Colicin-Mediated Transport of DNA through the Iron Transporter FepA

mBio ◽  
2021 ◽  
Author(s):  
Ruth Cohen-Khait ◽  
Ameya Harmalkar ◽  
Phuong Pham ◽  
Melissa N. Webby ◽  
Nicholas G. Housden ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Strains ◽  
Global Problem ◽  
Iron Transporter

Decades of excessive use of readily available antibiotics has generated a global problem of antibiotic resistance and, hence, an urgent need for novel antibiotic solutions. Bacteriocins are protein-based antibiotics produced by bacteria to eliminate closely related competing bacterial strains.

scholarly journals Antibacterial Compounds from Mushrooms: A Lead to Fight ESKAPEE Pathogenic Bacteria?

Planta Medica ◽  
2020 ◽  
Author(s):  
Violette Hamers ◽  
Clément Huguet ◽  
Mélanie Bourjot ◽  
Aurélie Urbain
Keyword(s):  
Antibiotic Resistance ◽  
Global Health ◽  
Pathogenic Bacteria ◽  
Resistance Mechanisms ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Antibacterial Compounds ◽  
New Antibiotics ◽  
Hospital Stays ◽  
Antibacterial Potential

AbstractInfectious diseases are among the greatest threats to global health in the 21st century, and one critical concern is due to antibiotic resistance developed by an increasing number of bacterial strains. New resistance mechanisms are emerging with many infections becoming more and more difficult if not impossible to treat. This growing phenomenon not only is associated with increased mortality but also with longer hospital stays and higher medical costs. For these reasons, there is an urgent need to find new antibiotics targeting pathogenic microorganisms such as ESKAPEE bacteria. Most of currently approved antibiotics are derived from microorganisms, but higher fungi could constitute an alternative and remarkable reservoir of anti-infectious compounds. For instance, pleuromutilins constitute the first class of antibiotics derived from mushrooms. However, macromycetes still represent a largely unexplored source. Publications reporting the antibacterial potential of mushroom extracts are emerging, but few purified compounds have been evaluated for their bioactivity on pathogenic bacterial strains. Therefore, the aim of this review is to compile up-to-date data about natural products isolated from fruiting body fungi, which significantly inhibit the growth of ESKAPEE pathogenic bacteria. When available, data regarding modes of action and cytotoxicity, mandatory when considering a possible drug development, have been discussed in order to highlight the most promising compounds.

Characterization, Pathogenicity, Phylogeny, and Comparative Genomic Analysis of Pseudomonas tolaasii Strains Isolated from Various Mushrooms in China

2021 ◽  
Author(s):  
Zhenghui Liu ◽  
Yitong Zhao ◽  
Frederick Leo Sossah ◽  
Benjamin Azu Okorley ◽  
Daniel G. Amoako ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Genomic Analysis ◽  
Gene Families ◽  
Effective Control ◽  
Economic Losses ◽  
Comparative Genomic ◽  
Bacterial Strains ◽  
Secretion Systems ◽  
Pseudomonas Tolaasii ◽  
Antimicrobial Resistance Genes

Since 2016, devastating bacterial blotch affecting the fruiting bodies of Agaricus bisporus, Cordyceps militaris, Flammulina filiformis, and Pleurotus ostreatus in China has caused severe economic losses. We isolated 102 bacterial strains and characterized them polyphasically. We identified the causal agent as Pseudomonas tolaasii and confirmed the pathogenicity of the strains. A host range test further confirmed the pathogen’s ability to infect multiple hosts. This is the first report in China of bacterial blotch in C. militaris caused by P. tolaasii. Whole-genome sequences were generated for three strains: Pt11 (6.48 Mb), Pt51 (6.63 Mb), and Pt53 (6.80 Mb), and pangenome analysis was performed with 13 other publicly accessible P. tolaasii genomes to determine their genetic diversity, virulence, antibiotic resistance, and mobile genetic elements. The pangenome of P. tolaasii is open, and many more gene families are likely to emerge with further genome sequencing. Multilocus sequence analysis using the sequences of four common housekeeping genes (glns, gyrB, rpoB, and rpoD) showed high genetic variability among the P. tolaasii strains, with 115 strains clustered into a monophyletic group. The P. tolaasii strains possess various genes for secretion systems, virulence factors, carbohydrate-active enzymes, toxins, secondary metabolites, and antimicrobial resistance genes that are associated with pathogenesis and adapted to different environments. The myriad of insertion sequences, integrons, prophages, and genome islands encoded in the strains may contribute to genome plasticity, virulence, and antibiotic resistance. These findings advance understanding of the determinants of virulence, which can be targeted for the effective control of bacterial blotch disease.

scholarly journals Antibiotic Sensitivity and Resistance Among the Most Common Uropathogens in Kidney Transplant Recipients

2015 ◽  
Vol 12 (1) ◽  
pp. 27-32
Author(s):  
Borelli Zlatkov ◽  
Jean Filipov ◽  
Emil Paskalev ◽  
Boyka Markova ◽  
Yuliya Marteva-Proevska ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Kidney Transplant ◽  
Antibiotic Sensitivity ◽  
High Sensitivity ◽  
Transplant Recipients ◽  
Kidney Transplant Recipients ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Transplant Center ◽  
Enterococcus Spp

Abstract Introduction. Urinary tract infection (UTI) among kidney transplant recipients (KTRs) is one of the most common complications after transplantation. The aim of our study was to analyze the antibiotic sensitivity and resistance of the most common agents causing UTI in Bulgarian KTRs followed up in our Transplant Center. Methods. We analyzed the antibiotic resistance and sensitivity of the most common strains of bacteria causing UTI in the Bulgarian KTRs, namely class Enterobac-teriaceae and Enterococcus spp. We used conventional biochemical methods to identify different strains of uro-pathogens-miniApi (bioMerieux, France) and BBL Crystal (BD). The antibiotic sensitivity was determined via disc-diffusing method, according to the accepted Bulgarian CLSI standard. We used WHONET, version 5.6 to analyze the antibiotic resistance data. Results. The total number of tested patients was 366 [males 228, females 138]. The total number of tested urine samples was 829 [positive ones-203), negative samples 606, contaminated 20]. The most commonly detected uropathogens in Bulgarian KTRs were Gram /-/ negative bacteria (63.80%). Of these, 93.28% belonged to the Enterobacteriaceae group, with E. coli, K. pneumoniae and the PPM /Proteus, Providentia, Mor-ganela/subgroup being the most common (54.5%, 19.20% and 16%, respectively). Gram /+/ positive bacteria were detected in 28.09% of the patients, Enterococcus spp being the most commonly isola-ted-67.79%. In the Enterococcus group, the strains of E. faecalis and E. faecium were the most commonly detected. The bacteria belonging to Enterobacteriaceae group were most sensitive to carbapenems and aminoglycosides, with sensitivity peaking to almost 100%, whereas they were least sensitive to aminopenicillines [sensitivity below 20%]. The PPM subgroup revealed very high sensitivity to beta-lactamase protected broad spectrum penicillins (Piperacillin/Tazobactam, sensitivity - 90%). Gram /+/ positive uropathogens were mostly sensitive to Linezolid, Vancomycin, Teicoplanin (100%). These strains were least sensitive to Erythromycin and Tetracicline (17.50%). Conclusions. Our results were similar to previous studies. The differences detected can be explained with the characteristics of the bacterial strains and the specific practice of each transplant center. Having in mind the possible complications of UTIs, further studies are needed to clarify the problem with antimicrobial resistance in uropathogens and the use of antibiotics after KT.

scholarly journals Genotypic characterization of antibiotic-resistant Salmonella Enteritidis isolates in Dakar, Senegal

2007 ◽  
Vol 1 (03) ◽  
pp. 284-288 ◽  
Author(s):  
Amy Gassama Sow ◽  
Abdoul Aziz Wane ◽  
Mamadou Hadi Diallo ◽  
Cheikh Saad-Bouh Boye ◽  
Awa Aïdara-Kane
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Data Bank ◽  
Human Infection ◽  
Molecular Techniques ◽  
Conjugative Plasmid ◽  
Bacterial Strains ◽  
Salmonella Enterica Serovar Enteritidis

Background: It is well established that Salmonella enterica is a major cause of food-borne disease worldwide. In Africa, according to the Who Global Salm-Surv country data bank from 2000 to 2002 Salmonella enterica serovar Enteritidis was the most common serotype involved in human salmonellosis. In Dakar this serotype of Salmonella has been reported as a frequent and an increasing cause of human infection. Methodology: The genetic determinants of the antimicrobial resistance of 25 selected multiresistant strains of Salmonella enterica serovar Enteritidis referred to the National Reference Center for Enterobacteria (NRCE) in Dakar were investigated using molecular techniques. Results: All strains carried blaTEM 1 genes. Five harboured three types of class 1 integrons with gene cassettes dfrA15, dfrA1-aadA1 and dfrA7. Multiresistance was due to a 23 Kb conjugative plasmid. DNA fingerprinting by macrorestriction of genomic DNA revealed a single related group suggesting that strains might be clonal. Conclusions: The spread of resistance genes through plasmid transfer plays an important role in the dissemination of antibiotic resistance in enteric pathogens such as Salmonella Enteritidis; the risk of transmissibility of antibiotic resistance between different bacterial strains highlights the urgent need to develop strategies to limit the spread of antimicrobial resistance among bacterial enteropathogens.

Antibiotic survey ofLactococcus lactisstrains to six antibiotics by Etest, and establishment of new susceptibility-resistance cut-off values

2007 ◽  
Vol 74 (3) ◽  
pp. 262-268 ◽  
Author(s):  
Ana Belén Flórez ◽  
Morten Danielsen ◽  
Jenni Korhonen ◽  
Joanna Zycka ◽  
Atte von Wright ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Inhibitory Concentration ◽  
Tetracycline Resistance ◽  
Large Collection ◽  
Bacterial Strains ◽  
Resistance Determinants ◽  
Resistant Strains ◽  
Geographical Locations ◽  
S Genes ◽  
Acquired Antibiotic Resistance

In order to establish cut-off values forLactococcus lactisto six antibiotics to distinguish susceptible and intrinsically resistant strains from those having acquired resistances, the minimum inhibitory concentration (MIC) of tetracycline, erythromycin, clindamycin, streptomycin, chloramphenicol and vancomycin was determined in 93 differentLc. lactisstrains using the Etest. These bacterial strains were originally isolated from dairy and animal sources in widely separated geographical locations. Cut-offs were defined on the basis of the distribution of the MICs frequency of the studied antibiotics, which in the absence of acquired determinants should approach to a normal statistical distribution. In general, the new cut-off values proposed in this study are higher than previously defined (European Commission, 2005. The EFSA Journal 223, 1–12). Based on these new values, all the strains tested were susceptible to erythromycin, chloramphenicol and vancomycin, and 79 susceptible to all six antibiotics. However, 11 strains (around 12%) were considered resistant to tetracycline (six of which had been identified after screening of a large collection of lactococci strains for tetracycline resistance) and five (5·4%) resistant to streptomycin. Of these, two fish isolates proved to be resistance to both tetracycline and streptomycin. From the tetracycline resistant strains,tet(M) and mosaictet(L/S) genes were amplified by PCR, demonstrating they harboured acquired antibiotic resistance determinants.

Development of antibiotic resistance in periprosthetic joint infection after total knee arthroplasty

2021 ◽  
Vol 103-B (6 Supple A) ◽  
pp. 171-176
Author(s):  
Antonio Klasan ◽  
Arne Schermuksnies ◽  
Florian Gerber ◽  
Matt Bowman ◽  
Susanne Fuchs-Winkelmann ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Antibiotic Resistance ◽  
Knee Arthroplasty ◽  
Periprosthetic Joint Infection ◽  
Joint Infection ◽  
Revision Arthroplasty ◽  
Bacterial Strains ◽  
Coagulase Negative Staphylococci ◽  
Primary Arthroplasty ◽  
Total Knee

Aims The management of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is challenging. The correct antibiotic management remains elusive due to differences in epidemiology and resistance between countries, and reports in the literature. Before the efficacy of surgical treatment is investigated, it is crucial to analyze the bacterial strains causing PJI, especially for patients in whom no organisms are grown. Methods A review of all revision TKAs which were undertaken between 2006 and 2018 in a tertiary referral centre was performed, including all those meeting the consensus criteria for PJI, in which organisms were identified. Using a cluster analysis, three chronological time periods were created. We then evaluated the antibiotic resistance of the identified bacteria between these three clusters and the effectiveness of our antibiotic regime. Results We identified 129 PJIs with 161 culture identified bacteria in 97 patients. Coagulase-negative staphylococci (CNS) were identified in 46.6% cultures, followed by Staphylococcus aureus in 19.8%. The overall resistance to antibiotics did not increase significantly during the study period (p = 0.454). However, CNS resistance to teicoplanin (p < 0.001), fosfomycin (p = 0.016), and tetracycline (p = 0.014) increased significantly. Vancomycin had an 84.4% overall sensitivity and 100% CNS sensitivity and was the most effective agent. Conclusion Although we were unable to show an overall increase in antibiotic resistance in organisms that cause PJI after TKA during the study period, this was not true for CNS. It is concerning that resistance of CNS to new antibiotics, but not vancomycin, has increased in a little more than a decade. Our findings suggest that referral centres should continuously monitor their bacteriological analyses, as these have significant implications for prophylactic treatment in both primary arthroplasty and revision arthroplasty for PJI. Cite this article: Bone Joint J 2021;103-B(6 Supple A):171–176.

scholarly journals In Vitro Evaluation of Gentamicin or Vancomycin Containing Bone Graft Substitute in the Prevention of Orthopedic Implant-Related Infections

2020 ◽  
Vol 21 (23) ◽  
pp. 9250
Author(s):  
Alessandro Bidossi ◽  
Marta Bottagisio ◽  
Nicola Logoluso ◽  
Elena De Vecchi
Keyword(s):  
Antibiotic Resistance ◽  
Bone Graft ◽  
Calcium Sulfate ◽  
Prolonged Exposure ◽  
Bacterial Colonization ◽  
Bone Graft Substitute ◽  
Bacterial Strains ◽  
Bone Graft Substitutes ◽  
Biofilm Development

Antibiotic-loaded bone graft substitutes are attractive clinical options and have been used for years either for prophylaxis or therapy for periprosthetic and fracture-related infections. Calcium sulfate and hydroxyapatite can be combined in an injectable and moldable bone graft substitute that provides dead space management with local release of high concentrations of antibiotics in a one-stage approach. With the aim to test preventive strategies against bone infections, a commercial hydroxyapatite/calcium sulfate bone graft substitute containing either gentamicin or vancomycin was tested against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa, harboring different resistance determinants. The prevention of bacterial colonization and biofilm development by selected microorganisms was investigated along with the capability of the eluted antibiotics to select for antibiotic resistance. The addition of antibiotics drastically affected the ability of the selected strains to adhere to the tested compound. Furthermore, both the antibiotics eluted by the bone graft substitutes were able to negatively impair the biofilm maturation of all the staphylococcal strains. As expected, P. aeruginosa was significantly affected only by the gentamicin containing bone graft substitutes. Finally, the prolonged exposure to antibiotic-containing sulfate/hydroxyapatite discs did not lead to any stable or transient adaptations in either of the tested bacterial strains. No signs of the development of antibiotic resistance were found, which confirms the safety of this strategy for the prevention of infection in orthopedic surgery.

scholarly journals Drug resistance in airborne bacteria isolated from waste management and wastewater treatment plants in Olsztyn

2019 ◽  
Vol 100 ◽  
pp. 00066 ◽  
Author(s):  
Jacek Potorski ◽  
Izabela Koniuszewska ◽  
Małgorzata Czatzkowska ◽  
Monika Harnisz
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Waste Management ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
Bacterial Counts ◽  
Air Samples ◽  
Processing Line

Wastewater treatment plants (WWTPs) and municipal waste management plants (MWMPs) emit bioaerosols containing potentially pathogenic biological components which post a threat for human health. Microbiological monitoring supports evaluations of the antibiotic resistance (AR) of airborne microorganisms and the relevant health risks. The aim of this study was to analyze the microbiological quality of air sampled in a WWTP and MWMP in Olsztyn based on total bacterial counts, the presence of bacteria resistant to three antibiotic classes (beta-lactams, tetracyclines and chloramphenicol) and genes encoding resistance to these antibiotics (blaTEM, blaSHV, blaCMY-2, blaAmpC, tet(M), tet(A), tet(X), tet(B), cmlA, floR, fexA, fexB and catA1 ). Bacterial counts were higher in air samples collected from the MWMP (~104 CFU/m3) than from the WWTP (101–103 CFU/m3). A similar trend was noted in the counts of antibiotic resistant bacteria (ARB). The abundance of ARB did not exceed 1.7 x 102 CFU/m3 in WWTP samples, but was higher at up to 4.2 x 103 CFU/m3 in MWMP samples. Bacteria resistant to doxycycline were least prevalent in the analyzed ARB. In the group of 49 tested bacterial strains, 44 harbored at least one of the analyzed antibiotic resistance genes (ARGs). A comparison of ARGs in all bacterial strains isolated from WWTP and MWMP air samples revealed the highest diversity and prevalence of ARGs in the samples collected in the mechanical segment of the waste processing line in MWMP and the biological segment of the wastewater processing line in WWTP. The results of this study point to high microbiological contamination of air in MWMPs and WWTPs which are reservoirs of ARB and ARGs and potential sources of AR.

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