<p>Comparative study of antimicrobial resistance and biofilm formation among Gram-positive uropathogens isolated from community-acquired urinary tract infections and catheter-associated urinary tract infections</p>

Abstract

Background: Gram-positive cocci have emerged to be an important cause of urinary tract infection (UTI) both in community-acquired UTI (Com-UTI) and catheter-associated urinary tract infection (CA-UTI). The objective of this study was to investigate the frequency of Gram-positive cocci urinary tract infections, their susceptibility patterns to commonly used antimicrobial agents and the biofilm forming property with respect to catheter-associated UTI and community-acquired UTI. Methods: A total of 1,360 urine samples from indwelling catheter and 10,423 from mid-stream urine were obtained during a 6-month period and processed following standard microbiological guidelines. Biofilm formation was detected using congo red agar (CRA), tube method (TM) and tissue culture plate (TCP) method. Chi-square test and independent sample t -test were employed to calculate the significance. Statistical significance was set at P -value ≤0.05. Results: The infection rate was significantly higher in CA-UTI as compared to Com-UTI (25% vs 18%, p =0.0001). Among 2,216 organisms isolated, 471 were Gram-positive cocci; 401 were obtained from Com-UTI while 70 were from CA-UTI. Enterococcus faecalis was the most common organism isolated from Com-UTI, while Staphylococcus aureus was commonest among CA-UTI. Multi-drug resistance, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci were also significantly higher in CA-UTI as compared to Com-UTI. Biofilm-forming property was significantly higher in CA-UTI than Com-UTI. The sensitivity of congo red agar method and tube method was 79% and 81.9% respectively and specificity was 98.5% each. Antimicrobial resistance was significantly higher in biofilm-formers as compared to non-formers. Conclusion: Gram-positive bacteria are a significant cause of both CA-UTI and Com-UTI with Enterococcus faecalis and Staphylococcus aureus as common pathogen. Biofilm formation and multi-drug resistance is significantly higher in CA-UTI than Com-UTI. Routine surveillance of antimicrobial resistance and biofilm formation is necessary in all cases of UTI to ensure the proper management of patients.

Increasing relevance of Gram-positive cocci in urinary tract infections: a 10-year analysis of their prevalence and resistance trends

“…To the best of our knowledge, this is the longest-spanning study reporting on the prevalence and susceptibility of this group of uropathogens in Hungary. In contrast to previous studies, dating back some 20–30 years (where the reported prevalence of Enterococcus spp., S. aureus and S. saprophyticus was 2–20%, 0.2–6% and 0.5–8%, respectively), based on current literature results, their prevalence is around 8–35%, 0.5–13% and 5–20%, respectively 48 – 55 . This increase is prevalence is especially notable in patients affected by recurrent UTIs (recurrence 3 or more times in 6 months) 44 .…”

“…Although the susceptibility-reporting for some of the antibiotics (e.g., fusidic acid, rifampicin, erythromycin, clindamycin, doxycycline and tigecycline) might seem frivolous in the context of the therapy of UTIs (as these drugs are not used in the therapy of these infections), the reporting of these results for epidemiological purposes is of interest, especially because not many studies are available regarding GPCs as uropathogens from Europe 66 . The prevalence of MRSA/VRSA and VRE isolates from urinary samples was advantageous in our study, and the levels of these isolates were similarly low in other literature reports as well, especially if we compare resistance levels of urinary isolates with invasive isolates (vancomycin-resistant E. faecalis : 0.0% [2008], 0.4% [2017]; vancomycin-resistant E. faecium : 2.8% [2008], 28.3% [2017]; MRSA: 22.5% [2008], 23.6% [2017], data from the European Antimicrobial Resistance Surveillance Network [EARS-Net]) 48 – 56 , 67 , 68 . On the other hand, the resistance levels to auxillary antimicrobials (aminoglycosides, fluoroquinolones) was shown to be high, and presenting in an increasing tendency (HLAR in enterococci: 53.3% [2008], 62.0% [2017], data from EARS-Net) 48 – 56 , 67 , 68 .…”

“…The prevalence of MRSA/VRSA and VRE isolates from urinary samples was advantageous in our study, and the levels of these isolates were similarly low in other literature reports as well, especially if we compare resistance levels of urinary isolates with invasive isolates (vancomycin-resistant E. faecalis : 0.0% [2008], 0.4% [2017]; vancomycin-resistant E. faecium : 2.8% [2008], 28.3% [2017]; MRSA: 22.5% [2008], 23.6% [2017], data from the European Antimicrobial Resistance Surveillance Network [EARS-Net]) 48 – 56 , 67 , 68 . On the other hand, the resistance levels to auxillary antimicrobials (aminoglycosides, fluoroquinolones) was shown to be high, and presenting in an increasing tendency (HLAR in enterococci: 53.3% [2008], 62.0% [2017], data from EARS-Net) 48 – 56 , 67 , 68 . S. saprophyticus is a common agent in UTIs, however, regarding its resistance patterns, it has proven so far to be mostly sensitive to the relevant antibiotics.…”

“…are present in fecal matter, therefore their anatomical proximity to the urinary tract may additionally enhance their UTI-causing capabilities 20 , 28 . Biofilm-production in these species is an another important factor for the emergence and the persistence of UTIs, with some reports suggesting that some 80% of uropathogenic Gram-positive cocci are biofilm-producers 48 . The presence of biofilm in urethral stents and catheters may lead to obstruction; furthermore, microorganisms embedded in biofilm may survive 1000-times higher concentrations of antibiotics, compared to non-embedded (i.e.…”

Status of Biofilm-Forming Genes among Jordanian Nasal Carriers of Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus

“…Nasal carriers of S. aureus might develop an endogenous infection, and consequently, they pose a threat of transmitting infection to susceptible individuals [ 1 ] . Accordingly, S. aureus accounts for the high numbers of nosocomial and community-acquired infections, as well as biomaterial contamination [ 2 , 3 ] . Moreover, these microorganisms have the potential to colonize medical catheters, tubing, surgical drains, and central lines by forming biofilms, which render them resistant to host defense mechanisms and antimicrobial therapy [ 4 , 5 ] .…”