scholarly journals Genetic diversity and biofilm formation analysis of Staphylococcus aureus causing urinary tract infections in Tehran, Iran

2019 ◽  
Vol 13 (09) ◽  
pp. 777-785 ◽  
Author(s):  
Mehdi Goudarzi ◽  
Anis Mohammadi ◽  
Anahita Amirpour ◽  
Maryam Fazeli ◽  
Mohammad Javad Nasiri ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Pcr Screening ◽  
Mrsa Strains ◽  
Tract Infections ◽  
Encoding Genes ◽  
Spa Types

Introduction: Over the past decades, prevalence of biofilm-forming Staphylococcus aureus strains has significantly increased in urinary tract infections. The aim of this study was to investigate prevalence of biofilm forming and adhesion encoding genes and to analyze distribution of different agr and spa types in S. aureus isolates. Methodology: In the present study, 75 S. aureus isolates obtained from patients with urinary tract infections were examined for susceptibility to antimicrobial agents. Adhesion, biofilm, and spa encoding genes were detected by PCR screening; agr types were determined using multiplex PCR. Results: Among the 75 isolates, 72% were biofilm producers and 28% were non-biofilm producers. Notably, the ability to produce biofilm was higher among MRSA strains ompared to MSSA strains. The most prevalent biofilm forming gene was icaD (77.3%), followed by icaA (76%), icaB (57.3%) and icaC (50.7%). Adhesion genes clfA, clfB, fnbB, can, fnbA, ebp and bap were detected in 94.7%, 92%, 68%, 64%, 64%, 60% and 5.3% of the isolates, respectively. The spa types t426 and t7789 were found among the non-MDR isolates. It was found that t790, t084, t7789 and t325 spa types were biofilm producers, while t426 and t1339 spa types were non-biofilm producers. Conclusion: Biofilm encoding genes icaD and spa type t790 and agr type III were the most prevalent factors among MDR biofilm producer isolates. The study emphasized that identification of genes and characterization of molecular types involved in biofilm formation should be considered.

scholarly journals Methicillin-resistant Staphylococcus aureus in urinary tract infections; prevalence and antimicrobial resistance

2021 ◽  
Vol 11 (1) ◽  
pp. e8-e8
Author(s):  
Raghad Abdulsalam Khaleel ◽  
Narjes Alfuraiji ◽  
Balsam Waleed Hussain ◽  
Maadh Fawzi Nassar ◽  
Farnoosh Ebrahimzadeh
Keyword(s):  
Staphylococcus Aureus ◽  
Urinary Tract ◽  
Antimicrobial Resistance ◽  
Urinary Tract Infections ◽  
Microbial Culture ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Tract Infections ◽  
Encoding Genes ◽  
Urine Specimens

Introduction: The newly-launched strain of the Staphylococcus aureus, methicillin-resistant S. aureus, is considered the most emerging bacterium in-hospital infections globally. Objectives: The current research focused on the prevalence and virulence features of methicillin-resistant S. aureus (MRSA) bacteria recovered from urinary tract infections (UTIs) cases. Patients and Methods: A total of 710 urine specimens were taken from hospitalized patients who suffered from UTIs. S. aureus was recovered from urine specimens using the microbial culture. S. aureus antimicrobial susceptibility was assessed toward oxacillin and cefoxitin antimicrobial disk to determine the MRSA strains. The polymerase chain reaction (PCR) assessed the distribution of antimicrobial resistance encoding genes. S. aureus antimicrobial resistance was evaluated by disk diffusion. Results: Fifty-five out of 710 (7.7%) urine specimens were positive for the MRSA bacteria. The uppermost antibiotic resistance was obtained against penicillin (100%), ceftaroline (100%), gentamicin (87.2%), erythromycin (76.3%), and ciprofloxacin (69.0%). BlaZ (100%) and tetK (85.4%) had the higher frequency amid examined antimicrobial resistance-encoding genes. Conclusion: The high prevalence of MRSA isolates harboring antimicrobial resistance-encoding genes in the UTIs suggests that diseases caused by them need more expansion healthcare monitoring with essential demand for novel antimicrobials.

scholarly journals Bacterial Biofilms; Links to Pathogenesis and Résistance Mechanism 

2018 ◽  
Author(s):  
Senait Tadesse Bekele ◽  
Getachew Kahsu Abay ◽  
Baye Gelaw ◽  
Belay Tessema
Keyword(s):  
Cystic Fibrosis ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Chronic Otitis Media ◽  
Surgical Removal ◽  
Chronic Infections ◽  
Native Valve ◽  
Tract Infections

Biofilms are usually defined as surface-associated microbial communities, surrounded by an extracellular polymeric substance matrix. There are three major steps that are observed in biofilm formation:  initial attachment events, microcolony formation and construction of mushroom-like structure with secretion of extracelluar polymeric substances. These substances can be considered a mechanism to protect the bacterial community from external insults.Biofilms, significantly increase the ability of the pathogen to evade both host defenses and antibiotics and they are being implicated in the pathogenesis and also clinical manifestation of several infections. They cause a variety of persistent infections, such as native valve endocarditis, osteomyelitis, dental caries, middle ear infections, ocular implant infections, urinary tract infections and cystic fibrosis. Established biofilms can tolerate antimicrobial agents at concentrations of 10–1000-times that needed to kill genetically equivalent planktonic bacteria, and are also resistant to phagocytosis, making biofilms extremely difficult to eradicate from living hosts. Consequently, biofilm-related infections that appear to respond to a therapeutic course of antibiotics may relapse weeks or even months later, making surgical removal and replacement of the infected tissue or medical device a frequent and unfortunate necessity.Several pathogens associated with chronic infections, including Pseudomonas aeruginosa in cystic fibrosis pneumonia, Haemophilus influenzae and Streptococcus pneumoniae in chronic otitis media and Enteropathogenic Escherichia coli in recurrent urinary tract infections, are linked to biofilm formation.

scholarly journals Urinary Excretion and Bactericidal Activities of Gemifloxacin and Ofloxacin after a Single Oral Dose in Healthy Volunteers

2001 ◽  
Vol 45 (12) ◽  
pp. 3524-3530 ◽  
Author(s):  
Christoph K. Naber ◽  
Michaela Hammer ◽  
Martina Kinzig-Schippers ◽  
Christian Sauber ◽  
Fritz Sörgel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Urinary Tract ◽  
Urinary Excretion ◽  
Enterococcus Faecalis ◽  
Urinary Tract Infections ◽  
Parent Drug ◽  
Oral Dosage ◽  
Tract Infections ◽  
Cumulative Excretion

ABSTRACT In a randomized crossover study, 16 volunteers (8 men, 8 women) received single oral doses of 320 mg of gemifloxacin and 400 mg of ofloxacin on two separate occasions in the fasting state to assess the urinary excretion and urinary bactericidal titers (UBTs) at intervals for up to 144 h. Ofloxacin showed higher concentrations in urine compared with those of gemifloxacin. The median (range) cumulative excretion of gemifloxacin was 29.7% (8.4 to 48.7%) of the parent drug administered, and median (range) cumulative excretion of ofloxacin was 84.3% (46.5 to 95.2%) of the parent drug administered. The UBTs, i.e., the highest twofold dilutions (with antibiotic-free urine as the diluent) of urine that were still bactericidal, were determined for a reference strain and nine uropathogens for which the MICs of gemifloxacin and ofloxacin were as follows:Escherichia coli ATCC 25922, 0.016 and 0.06 μg/ml, respectively; Klebsiella pneumoniae, 0.03 and 0.06 μg/ml, respectively; Proteus mirabilis, 0.125 and 0.125 μg/ml, respectively; Escherichia coli, 0.06 and 0.5 μg/ml, respectively; Pseudomonas aeruginosa, 1 and 4 μg/ml, respectively; Staphylococcus aureus, 0.008 and 0.25 μg/ml, respectively; Enterococcus faecalis, 0.06 and 2 μg/ml, respectively;Staphylococcus aureus, 0.25 and 4 μg/ml, respectively;Enterococcus faecalis, 0.5 and 32 μg/ml, respectively; and Staphylococcus aureus, 2 and 32 μg/ml, respectively. Generally, the UBTs for gram-positive uropathogens were higher for gemifloxacin than for ofloxacin and the UBTs for gram-negative uropathogens were higher for ofloxacin than for gemifloxacin. According to the UBTs, ofloxacin-resistant uropathogens (MICs, ≥4 mg/liter) should also be considered gemifloxacin resistant. Although clinical trials have shown that gemifloxacin is effective for the treatment of uncomplicated urinary tract infections, whether an oral dosage of 320 mg of gemifloxacin once daily is also adequate for the treatment of complicated urinary tract infections has yet to be confirmed.

Update on the Treatment of Bacterial Urinary Tract Infections

1981 ◽  
Vol 15 (10) ◽  
pp. 738-750 ◽  
Author(s):  
Neil Massoud
Keyword(s):  
Biological Activity ◽  
Single Dose ◽  
Urinary Tract ◽  
Patient Compliance ◽  
Urinary Tract Infections ◽  
Antimicrobial Agents ◽  
Complex Problem ◽  
Tract Infections

The treatment of urinary tract infections (UTIs) has become a complex problem for the clinical practitioner. An understanding of the pharmacology, pharmacokinetics, and in vivo biological activity of antimicrobial agents is needed, as is an understanding of the variables that may influence patient compliance with medication regimens. Although UTIs are usually treated for 10 to 14 days, shorter treatment schedules of seven to ten days or even single-dose regimens are possible. Guidelines for the treatment of UTIs are presented along with suggestions for increased patient compliance.

scholarly journals Human urine alters methicillin-resistant Staphylococcus aureus virulence and transcriptome

2021 ◽  
Author(s):  
Santosh Paudel ◽  
Kamal Bagale ◽  
Swapnil Patel ◽  
Nicholas J. Kooyers ◽  
Ritwij Kulkarni
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Human Urine ◽  
Molecular Mechanisms ◽  
Methicillin Resistant ◽  
Life Threatening ◽  
Tract Infections

Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) is an emerging cause of hospital-associated urinary tract infections (UTI), especially in catheterized individuals. Despite being rare, MRSA UTI are prone to potentially life-threatening exacerbations such as bacteremia that can be refractory to routine antibiotic therapy. To delineate the molecular mechanisms governing MRSA urinary pathogenesis, we exposed three S. aureus clinical isolates, including two MRSA strains to human urine for 2h and analyzed virulence characteristics and changes in gene expression. The in vitro virulence assays showed that human urine rapidly alters adherence to human bladder epithelial cells and fibronectin, hemolysis of sheep RBCs, and surface hydrophobicity in a staphylococcal strain-specific manner. In addition, RNA-Seq analysis of uropathogenic strain MRSA-1369 revealed that 2h-long exposure to human urine alters MRSA transcriptome, by modifying expression of genes encoding enzymes catalyzing metabolic pathways, virulence factors, and transcriptional regulators. In summary, our results provide important insights into how human urine specifically and rapidly alters MRSA physiology and facilitates MRSA survival in the nutrient-limiting and hostile urinary microenvironment. Importance: Methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon cause of urinary tract infections (UTI) in the general population. However, it is important to understand MRSA pathophysiology in the urinary tract because isolation of MRSA in urine samples often precedes potentially life-threatening MRSA bacteremia. In this report, we describe how exposure to human urine alters MRSA global gene expression and virulence. We hypothesize that these alterations may aid MRSA in acclimating to the nutrient-limiting, immunologically hostile conditions within the urinary tract leading to MRSA-UTI.

scholarly journals Derivation of a Calculation Formula for Breakpoints of Antimicrobial Agents in Urinary Tract Infections

1998 ◽  
Vol 4 (2) ◽  
pp. 97-106 ◽  
Author(s):  
Soichi Arakawa ◽  
Takashi Matsui ◽  
Sadao Kamidono ◽  
Yukimichi Kawada ◽  
Hiromi Kumon ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Antimicrobial Agents ◽  
Calculation Formula ◽  
Tract Infections
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