scholarly journals Antibiotic resistance alters through iron-regulating Sigma factors during the interaction of Staphylococcus aureus and Pseudomonas aeruginosa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamed Tahmasebi ◽  
Sanaz Dehbashi ◽  
Mohammad Reza Arabestani

AbstractIron is a limiting factor in such a condition that usually is sequestered by the host during polymicrobial infections of Pseudomonas aeruginosa and Staphylococcus aureus. This study aimed to investigate the interaction of S. aureus and P. aeruginosa, which alters iron-related sigma factors regulation and antibiotic resistance. The antibiotic resistance of P. aeruginosa and S. aureus was investigated in a L929 cell culture model. The expression level of pvdS, hasI (P. aeruginosa sigma factors), and sigS (S. aureus sigma factor) genes was determined using Quantitative Real-Time PCR. pvdS and hasI were downregulated during co-culture with S. aureus, while the susceptibility to carbapenems increased (p-value < 0.0001). Also, there was a direct significant relationship between resistance to vancomycin with sigS. Regarding the findings of the current study, iron-related sigma factors of P. aeruginosa and S. aureus play a role in induction susceptibility to various antibiotics, including carbapenems and vancomycin.

Author(s):  
Parag Sharma

ABSTRACTBronchiectasis is a type of chronic obstructive pulmonary disease, defined as permanent abnormal dilation of bronchi due to vicious cycle of transmuralinfection and inflammation. Bronchiectasis is generally characterized by cough, wheeze, and dyspnea. Pathogens responsible for bronchiectasisinclude pathogens Haemophilus influenzae, Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus aureus, and nontuberculousmycobacteria. Empirical antibiotic therapy and other drugs are used empirically in the management of bronchiectasis.Here, we discuss a case ofinfectious exacerbation of bronchiectasis successfully treated with an empirical use of ceftriaxone/sulbactam/disodium edetate-1034.Keywords: Bronchiectasis, Elores™, Ceftriaxone/sulbactam/disodium edetate-1034, Disodium edetate, Antibiotic resistance.


2021 ◽  
Vol 11 (6) ◽  
pp. 1075-1082
Author(s):  
S. Derakhshan ◽  
A. Rezaee ◽  
Sh. Mohammadi

Background and aim. Pseudomonas aeruginosa is considered as a notorious pathogen due to its multidrug resistance and life threatening infections. We investigated the relationship between type III secretion toxins, biofilm formation, and antibiotic resistance among clinical P. aeruginosa isolates. Methods. A total of 70 genetically distinct clinical P. aeruginosa isolates were characterized for antibiotic resistance by disk diffusion assay. Biofilm formation was evaluated by microtiter plate method and presence of four exo genes (exoS, exoU, exoT and exoY) was investigated by PCR. A p-value < 0.05 was regarded statistically significant. Results. The most effective antibiotics were Meropenem and Piperacillin. Multidrug resistance was more prevalent in the ciprofloxacin-resistant isolates than in the susceptible isolates. The most frequently identified exo was exoS (37.1%). Genotype exoS/exoT was found in 4 isolates, while genotype exoU/exoT was not found. Prevalence of exoS was generally higher in the susceptible isolates than in the resistant isolates. A significant association was found between the formation of strong biofilm and resistance to antibiotics (p < 0.05). Prevalence of exoY and exoU was higher in the non-strong biofilm producers compared to the strong biofilm producers. Conclusion. Our study revealed formation of strong biofilm along with antibiotic resistance and the presence of exo genes in P. aeruginosa isolates. Knowledge of virulence gene profiles and biofilm formation may be useful in deciding appropriate treatment.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Paul Briaud ◽  
Laura Camus ◽  
Sylvère Bastien ◽  
Anne Doléans-Jordheim ◽  
François Vandenesch ◽  
...  

Abstract Cystic fibrosis (CF) is the most common life-threatening genetic disease among Caucasians. CF patients suffer from chronic lung infections due to the presence of thick mucus, caused by cftr gene dysfunction. The two most commonly found bacteria in the mucus of CF patients are Staphylococcus aureus and Pseudomonas aeruginosa. It is well known that early-infecting P. aeruginosa strains produce anti-staphylococcal compounds and inhibit S. aureus growth. More recently, it has been shown that late-infecting P. aeruginosa strains develop commensal-like/coexistence interaction with S. aureus. The aim of this study was to decipher the impact of P. aeruginosa strains on S. aureus. RNA sequencing analysis showed 77 genes were specifically dysregulated in the context of competition and 140 genes in the context of coexistence in the presence of P. aeruginosa. In coexistence, genes encoding virulence factors and proteins involved in carbohydrates, lipids, nucleotides and amino acids metabolism were downregulated. On the contrary, several transporter family encoding genes were upregulated. In particular, several antibiotic pumps belonging to the Nor family were upregulated: tet38, norA and norC, leading to an increase in antibiotic resistance of S. aureus when exposed to tetracycline and ciprofloxacin and an enhanced internalization rate within epithelial pulmonary cells. This study shows that coexistence with P. aeruginosa affects the S. aureus transcriptome and virulence.


2018 ◽  
Vol 101 (4) ◽  
pp. 956-959 ◽  
Author(s):  
Maria Anna Coniglio ◽  
Pasqualina Laganà ◽  
Giuseppina Faro ◽  
Marina Marranzano

Abstract The purpose of this study was to investigate the antibacterial effect of 71 organic Sicilian honeys of different botanical origins against Staphylococcus aureus [American Type Culture Collection (ATCC) 9144™] and Pseudomonas aeruginosa (ATCC 27853™). The antimicrobial activity was determined by means of an agar diffusion assay from the estimation of the diameter of the inhibition zone produced by the honeys. S. aureus was more inhibited than P. aeruginosa (chi-square value 11.2698, P value 0.000788). In particular, a statistically significant inhibition growth against S. aureus was exhibited by the polyfloral (chi-square value 6.1714, P value 0.012983) and the eucalyptus honeys (chi-square value 4, P value 0.0455). Results partially suggest Sicilian organic polyfloral and eucalyptus honeys as possible alternatives to antimicrobial agents when S. aureus resistance causes failure of initial conventional antibiotic treatment.


mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Nadia K. Monych ◽  
Raymond J. Turner

Alternative antimicrobials, such as metals, are one of the methods currently used to help mitigate antibiotic resistance. Metal-based antimicrobials such as copper and silver are used currently both to prevent and to treat infections. Although the efficacy of these antimicrobials has been determined in single-species culture, bacteria rarely exist in a single-species group in the environment. Both Pseudomonas aeruginosa and Staphylococcus aureus are often found associated with each other in severe chronic infections displaying increased virulence and antibiotic tolerance. In this study, we determined that multiple compounds secreted by P. aeruginosa are able to increase the tolerance of S. aureus to both copper and silver. This work demonstrates the expansive chemical communication occurring in polymicrobial infections between bacteria.


2020 ◽  
Vol 14 (3) ◽  
pp. 1961-1966
Author(s):  
A. Deboral ◽  
Namrata K. Bhosale ◽  
S. Umadevi

The antibiotic resistance pattern was observed significantly in various geographical locations. Routine surveillance is therefore essential for constant monitoring of AMR rates in the clinically important pathogens. It is imperative to track the changing resistance pattern over time, to guide proper therapeutic strategies to combat infections due to drug-resistant pathogens. This study aims to highlights the distribution of aerobic bacterial isolated from pus samples, and their susceptibility to different antibiotics collected during 2017 (July to December) in a tertiary care hospital. Nearly 637 clinical pus samples were received during July to December 2017 to the Department of Microbiology, Tertiary care hospital, Puducherry. Bacterial identification was performed using standard conventional biochemical tests and antibiotic susceptibility was carried out according to CLSI guidelines 2017 on each one of the aerobic bacterial isolates from the pus samples. Among the isolates 76.5% were Gram-negative bacilli (GNB) as well as 23.5% were Gram-positive cocci (GPC). The most common bacteria isolated were Pseudomonas spp 24.88% (108 in 434), followed by Escherichia coli 21.66% (94 in 434), Staphylococcus aureus 19.82% (86 in 434) and Klebsiella pneumoniae 13.13% (57 in 434). Of the 86 (19.82%) Staphylococcus aureus isolates, 16 (18.40%) were MRSA. Pseudomonas aeruginosa was highly susceptible to the carbapenems and least susceptible to ciprofloxacin. Acinetobacter baumannii was the most resistant organism according to this study and showed the least susceptibility to ceftriaxone and maximum susceptibility to aminoglycosides. This study concluded that the Pseudomonas aeruginosa isolate was found to be a predominant in our clinical pus samples. Gram negative bacteria are more commonly associated with the pyogenic lesion that Gram positive. A high level of an antibiotic resistance was observed in most of our bacterial isolates.


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