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PHRP : Osong Public Health and Research Perspectives

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Original Articles
Relationships between Virulence Factors and Antimicrobial Resistance among Escherichia coli Isolated from Urinary Tract Infections and Commensal Isolates in Tehran, Iran
Mohammad Reza Asadi Karam, Mehri Habibi, Saeid Bouzari
Osong Public Health Res Perspect. 2018;9(5):217-224.   Published online October 31, 2018
DOI: https://doi.org/10.24171/j.phrp.2018.9.5.02
  • 3,540 View
  • 103 Download
  • 16 Citations
AbstractAbstract PDF
Objectives

Uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections (UTIs). Here, we determined whether sensitivity to antibiotics was related to the prevalence of iron scavenging genes, or to biofilm and hemolysis formation.

Methods

A total of 110 UPEC and 30 E coli isolates were collected from the urine of UTI patients and feces of healthy individuals without UTI, respectively. The presence of iron receptor genes and phenotypic properties were evaluated by polymerase chain reaction and phenotypic methods, respectively. Susceptibility to routine antibiotics was evaluated using the disc diffusion method.

Results

The prevalence of iron scavenging genes ranged from 21.8% (ireA) to 84.5% (chuA) in the UPEC. Resistance to ceftazidime and cefotaxime was significantly correlated with the presence of fyuA and iutA iron genes. Biofilm production was significantly associated with the prevalence of fyuA and hma iron genes. A higher degree of antibiotic resistance was exhibited by isolates that produced biofilms than by their non-biofilm producing counterparts.

Conclusion

Our study clearly indicates that biofilm production is associated with antibiotic resistance, and that iron receptors and hemolysin production also contribute to reduced antibiotic sensitivity. These results further our understanding of the role that these virulence factors play during UPEC pathogenesis, which in turn may be valuable for the development of novel treatment strategies against UTIs.

Evaluation of Biofilm Formation and Presence of Ica Genes in Staphylococcus epidermidis Clinical Isolates
Maryam Kord, Abdollah Ardebili, Maryam Jamalan, Roghaye Jahanbakhsh, Naser Behnampour, Ezzat Allah Ghaemi
Osong Public Health Res Perspect. 2018;9(4):160-166.   Published online August 31, 2018
DOI: https://doi.org/10.24171/j.phrp.2018.9.4.04
  • 3,574 View
  • 147 Download
  • 3 Citations
AbstractAbstract PDF
Objectives

Biofilm formation is one of the important features of Staphylococcus epidermidis, particularly in nosocomial infections. We aimed to investigate the biofilm production by phenotypic methods and the presence of ica genes in S epidermidis.

Methods

A total of 41 S epidermidis isolates were recovered from different clinical specimens. Biofilm formation was evaluated by microtiter plate, tube method and Congo red agar method. The presence of icaA and icaD genes was investigated by PCR. Validity of methods (sensitivity and specificity), and metrics for test performance (positive/negative predictive value, and positive/negative likelihood ratio) were determined.

Results

By both microtiter plate and tube method, 53.6% of S epidermidis isolates were able to produce biofilm, whilst only 24.4% of isolates provided a biofilm phenotype on Congo red agar plates. icaA and icaD genes were found in 100% and 95.1% of isolates, respectively. Biofilm phenotypes accounted for 4.8% by microtiter plate assay, despite the absence of the ica gene. Congo red agar and PCR exhibited a lower sensitivity (18% and 45.5%, respectively) for identifying the biofilm phenotype in comparison to microtiter plate.

Conclusion

The microtiter plate method remains generally a better tool to screen biofilm production in S epidermidis. In addition, the ability of S epidermidis to form biofilm is not always dependent on the presence of ica genes, highlighting the importance of ica-independent mechanisms of biofilm formation. The use of reliable methods to specifically detect biofilms can be helpful to treat the patients affected by such problematic bacteria.

Anti-biofilm Properties of Peganum harmala against Candida albicans
Elham Aboualigalehdari, Nourkhoda Sadeghifard, Morovat Taherikalani, Zaynab Zargoush, Zahra Tahmasebi, Behzad Badakhsh, Arman Rostamzad, Sobhan Ghafourian, Iraj Pakzad
Osong Public Health Res Perspect. 2016;7(2):116-118.   Published online April 30, 2016
DOI: https://doi.org/10.1016/j.phrp.2015.12.010
  • 1,735 View
  • 18 Download
  • 11 Citations
AbstractAbstract PDF
Objectives
Vaginitis still remains as a health issue in women. It is notable that Candida albicans producing biofilm is considered a microorganism responsible for vaginitis with hard to treat. Also, Peganum harmala was applied as an anti fungal in treatment for many infections in Iran. Therefore, this study goal to investigate the role of P. harmala in inhibition of biofilm formation in C. albicans.
Methods
So, 27 C. albicans collected from women with Vaginitis, then subjected for biofilm formation assay. P. harmala was applied as antibiofilm formation in C. albicans.
Results
Our results demonstrated that P. harmala in concentration of 12 μg/ml easily inhibited strong biofilm formation; while the concentrations of 10 and 6 μg/ml inhibited biofilm formation in moderate and weak biofilm formation C. albicans strains, respectively.
Conclusion
Hence, the current study presented P. harmala as antibiofilm herbal medicine for C. albicans; but in vivo study suggested to be performed to confirm its effectiveness.
Investigation of Biofilm Formation and its Association with the Molecular and Clinical Characteristics of Methicillin-resistant Staphylococcus aureus
Jeong-Ok Cha, Jae Il Yoo, Jung Sik Yoo, Hae-Sun Chung, Sun-Hee Park, Hwa Su Kim, Yeong Seon Lee, Gyung Tae Chung
Osong Public Health Res Perspect. 2013;4(5):225-232.   Published online October 31, 2013
DOI: https://doi.org/10.1016/j.phrp.2013.09.001
  • 1,844 View
  • 13 Download
  • 44 Citations
AbstractAbstract PDF
Objectives
To investigate the biofilm-forming related factors against MRSA bloodstream isolates and evaluates their clinical features and treatment outcomes by biofilm production.
Methods
We collected 126 consecutive methicillin-resistant Staphylococcus aureus (MRSA) causing blood stream infections (BSIs) at 10 tertiary hospitals from 2007 to 2009. We investigated biofilm-forming ability using a microtiter plate assay, and molecular characteristics including multilocus sequence typing, staphylococcal cassette chromosome mec and accessory gene regulator types. We compared the clinical characteristics and outcomes of patients infected with biofilm-forming and non-biofilm-forming MRSA isolates.
Results
Of the 126 samples, 86 (68.3%), including 5 strong level (OD570 ≥ 1.0) and 81 weak level (0.2 ≤ OD570 < 1.0), had biofilm-forming capacity. Detection of fibronectinbinding protein in biofilm-forming strains was significantly higher than biofilm non-forming ones (p = 0.001) and three enterotoxin genes (sec-seg-sei) islands had a high frequency regardless of biofilm production. However, biofilm-forming strains were more likely to be multidrug resistant (three or more non-β-lactam antibiotics) than biofilm non-forming ones [79.2% vs. 59.2%, p = 0.015, odds ratio (OR) 2.629, 95% confidence interval (CI) 1.92–5.81]. Clinical features of patients with BSIs caused by biofilm-forming MRSA strains were more likely to be hospital onset [77.9% vs. 60.0%, p = 0.024, OR 2.434, 95% CI 1.11–5.33) and more frequently occurred in patients with use of invasive devices [85.7% vs. 61.2%, p = 0.002, OR 3.879, 95% CI 1.61–8.97]. The other clinical features were compared with the clinical outcomes of the two groups and were not significant (p > 0.05).
Conclusion
Biofilm-forming MRSA strains showed higher frequency of fnbB gene than biofilm non-forming ones and more incidence rates on particular genotypes. And, their patient's features were not significantly different between two groups in this study, except for several clinical factors.

PHRP : Osong Public Health and Research Perspectives