Prevalence of Catheter-associated bacteriuria in patients who received short-term catheterization in the northeast of Iran

Background: Catheter-associated (CA) bacteriuria is a result of the extensive usage of urinary catheterization. Once a catheter is placed, many patients achieve bacteriuria, even with the use of greatest consideration and care of the catheter. In this study, we decided to evaluate the prevalence of Catheter-associated bacteriuria in patients who received short-term catheterization in the northeast of Iran.Materials and Methods: In this cross-sectional study during one year (among 2014-2015) 275 patients who have admitted recently and have no history of catheterization and drug consumption were included. Three samples were taken from patients before, one day after catheterization and after removal of the catheter. The urine samples were analyzed and cultured on the suitable media. Antibiotics susceptibility testing was performed by disk diffusion method. Then, data analyzed using SPSS software by Student t-test. In addition, the p values less than 0.05 were considered as significant.Results: In general, the rate of catheter-associated bacteriuria in these hospitals was 68% (187 cases of 275). The mean age of the participants and patients with bacteriuria were 41±1.2 and 24.8±6.2 years old, respectively. The most common isolated bacteria were Escherichia coli (50.6%) followed by Staphylococcus aureus and Klebsiella pneumonia (21.6%). The highest sensitivity was reported against kanamycin (68.9%) and highest resistance was observed against ampicillin with a rate of 96.3%.Conclusion: For prevention of healthcare-associated UTI, correct catheterization and use of the closed catheter system is recommended. In addition, before prescribing any antibiotics it should be paying attention to the antibiotics susceptibility testing results

Modified genome comparison method: a new approach for identification of specific targets in molecular diagnostic tests using Mycobacterium tuberculosis complex as an example

Abstract Background The first step of designing any genome-based molecular diagnostic test is to find a specific target sequence. The modified genome comparison method is one of the easiest and most comprehensive ways to achieve this goal. In this study, we aimed to explain this method with the example of Mycobacterium tuberculosis complex and investigate its efficacy in a diagnostic test. Methods A specific target was identified using modified genome comparison method and an in-house PCR test was designed. To determine the analytical sensitivity and specificity, 10 standard specimens were used. Also, 230 specimens were used to determine the clinical sensitivity and specificity. Results The identity and query cover of our new diagnostic target (5KST) were ≥ 90% with M. tuberculosis complex. The 5KST-PCR sensitivity was 100% for smear-positive, culture-positive and 85.7% for smear-negative, culture-positive specimens. All of 100 smear-negative, culture-negative specimens were negative in 5KST-PCR (100% clinical specificity). Analytical sensitivity of 5KST-PCR was approximately 1 copy of genomic DNA per microliter. Conclusions Modified genome comparison method is a confident way to find specific targets for use in diagnostic tests. Accordingly, the 5KST-PCR designed in this study has high sensitivity and specificity and can be replaced for conventional TB PCR tests

The Frequency of VIM 2, 3, 9, 11 and VIM all among Metallo-beta-Lactamase Producing Pseudomonas aeruginosa

Introduction: Antibiotic resistance crisis has always been a serious problem for human health and many hospitalized patients are affected worldwide. Pseudomonas aeruginosa is a gram-negative pathogen and one of the most common causes of nosocomial infections. The main mechanism of resistance to beta-lactam antibiotics is the presence of metallo-beta-lactamase (MBL) enzymes. Most of the MBL genes are found in plasmids. The aim of this study was to evaluate the frequency of MBL-producing P. aeruginosa isolates caused by VIM-all and VIM 2, 3, 9, 11and16 genes.   Materials & Methods: Antimicrobial susceptibility of 127 clinical isolates of P. aeruginosa was determined using the standard Kirby-Bauer disk diffusion method according to Clinical and Laboratory Standard Institute (CLSI). Combined-disk test was used for phenotypic determination of MBLs-producing isolates. After DNA extraction, VIM-all and in specific, VIM 2, 3, 9, 11 and 16 genes were amplified using PCR method.   Findings: A total Of 127 clinical isolates of P. aeruginosa, 62 isolates (49%) were resistant to imipenem and 31 isolates (24.5%) showed phenotypic evidences of MBL production. Moreover, among imipenem resistant strains VIM-all genes were found in 12.5% of cases, but the VIM 2-3-9-11 and 16 genes were not detected in samples.   Discussion & Conclusions: The results obtained in this study suggest that in P. aeruginosa, the highest antibiotic resistance observed was to cefazolin (98%) followed by nalidixic acid (91%) and the least resistance were to ciprofloxacin (31%). One of the reasons for this trend is the growth of antibiotic-resistant bacteria and the known mechanisms of bacterial resistance