Impact of Multidrug Resistance on Experimental Empyema by Pseudomonas aeruginosa

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.

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In Vitro Potency of CXA-101, a Novel Cephalosporin, against Pseudomonas aeruginosa Displaying Various Resistance Phenotypes, Including Multidrug Resistance

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00912-09 ◽

2009 ◽

Vol 54 (1) ◽

pp. 557-559 ◽

Cited By ~ 31

Author(s):

Catharine C. Bulik ◽

Henry Christensen ◽

David P. Nicolau

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistance

ABSTRACT We describe the activity of a novel cephalosporin, CXA-101 (FR26 4205), against a panel of highly resistant Pseudomonas aeruginosa isolates collected from U.S. hospitals. CXA-101 demonstrated increased potency against this population of resistant isolates, with activity that is 4- to 10-fold higher than that of comparator agents in each phenotypic category. The addition of tazobactam did not improve its activity. CXA-101 appears to be a promising addition to the category of antipseudomonal β-lactams.

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Acquisition of multidrug resistance transposon Tn6061 and IS6100-mediated large chromosomal inversions in Pseudomonas aeruginosa clinical isolates

Microbiology ◽

10.1099/mic.0.033639-0 ◽

2010 ◽

Vol 156 (5) ◽

pp. 1448-1458 ◽

Cited By ~ 23

Author(s):

Sébastien Coyne ◽

Patrice Courvalin ◽

Marc Galimand

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistance ◽

Opportunistic Pathogen ◽

Clinical Isolates ◽

Chromosomal Inversions ◽

Gene Acquisition ◽

Drug Classes ◽

Horizontal Acquisition

Pseudomonas aeruginosa is a major human opportunistic pathogen, especially for patients in intensive care units or with cystic fibrosis. Multidrug resistance is a common feature of this species. In a previous study we detected the ant(4′)-IIb gene in six multiresistant clinical isolates of P. aeruginosa, and determination of the environment of the gene led to characterization of Tn6061. This 26 586 bp element, a member of the Tn3 family of transposons, carried 10 genes conferring resistance to six drug classes. The ant(4′)-IIb sequence was flanked by directly repeated copies of ISCR6 in all but one of the strains studied, consistent with ISCR6-mediated gene acquisition. Tn6061 was chromosomally located in six strains and plasmid-borne in the remaining isolate, suggesting horizontal acquisition. Duplication-insertion of IS6100, that ended Tn6061, was responsible for large chromosomal inversions. Acquisition of Tn6061 and chromosomal inversions are further examples of intricate mechanisms that contribute to the genome plasticity of P. aeruginosa.

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Aortic Prosthesis-Associated MDR Pseudomonas Infections as a Diagnostic and Therapeutic Challenge

Infectious Disease Reports ◽

10.3390/idr12030012 ◽

2020 ◽

Vol 12 (3) ◽

pp. 46-50

Author(s):

Rita Filipe ◽

Filipa Ceia ◽

Ana Cláudia Carvalho ◽

Margarida Tavares ◽

José Teixeira ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistance ◽

Antibiotic Treatment ◽

Treatment Options ◽

Aortic Aneurysms ◽

Oral Antibiotic ◽

Significant Morbidity ◽

Prosthetic Infection ◽

Aortic Prosthesis ◽

Life Threatening

Endovascular prostheses are used to treat life-threatening conditions such as ruptured aortic aneurysms. Prosthetic infection cause significant morbidity and mortality, posing important diagnostic and therapeutic challenges. It is particularly difficult to diagnose and, in the era of multidrug resistance (MDR), these type of infections may become even more difficult to treat. Herein, we reported a case of a secondary prosthetic endovascular infection following repeated bacteremia episodes from a urinary source. This case illustrates an MDR Pseudomonas aeruginosa aortic infection that was difficult to diagnose with no oral antibiotic treatment options.

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Roles of MexXY- and MexAB-multidrug efflux pumps in intrinsic multidrug resistance of Pseudomonas aeruginosa PAO1.

The Journal of General and Applied Microbiology ◽

10.2323/jgam.47.27 ◽

2001 ◽

Vol 47 (1) ◽

pp. 27-32 ◽

Cited By ~ 54

Author(s):

Yuji Morita ◽

Nobuhisa Kimura ◽

Takehiko Mima ◽

Tohru Mizushima ◽

Tomofusa Tsuchiya

Keyword(s):

Pseudomonas Aeruginosa ◽

Multidrug Resistance ◽

Efflux Pumps ◽

Multidrug Efflux ◽

Pseudomonas Aeruginosa Pao1 ◽

Multidrug Efflux Pumps

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An usual approach to treatment of a case of multidrug resistance Pseudomonas aeruginosa peritonitis: parenteral and intraperitoneal aminoglycosides and parenteral colistin

Infectious Disease Reports ◽

10.4081/idr.2012.e36 ◽

2012 ◽

Vol 4 (1) ◽

pp. 36 ◽

Cited By ~ 1

Author(s):

Ian May ◽

Maha Abu-Khdeir ◽

Roland Alexander Blackwood

Keyword(s):

Pseudomonas Aeruginosa ◽

Drug Resistance ◽

Intensive Care ◽

Multidrug Resistance ◽

Pleural Cavity ◽

Abdominal Cavity ◽

Multi Drug Resistance ◽

Clinical Settings ◽

Intravenous Antibiotics ◽

Polymyxin E

Infections caused by Pseudomonas aeruginosa are becoming more common and increasingly more difficult to treat due to the continued development of drug resistance. While sensitivity to colistin (polymyxin E) is well known, it is frequently avoided due to concerns of nephrotoxicity. Reported here is a case of a multi-drug resistance pseudomonal typhlitis, bacteremia and pleural cavity infection that required significant intensive care, and serial abdominal washouts. Intra-peritoneal tobramycin in combination with broad-spectrum intravenous antibiotics including colistin were used. Several instillations of tobramycin into the abdominal cavity along with concomitant IV administration of colistin, ceftazidime and tobramycin and per os colistin, tobramycin and nystatin resulted in the clearance of the pseudomonal infection without any evidence of toxicity from the treatment. Intra-abdominal tobramycin with parenteral colistin therapy can be used in complicated clinical settings with appropriate nephroprotection.

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