Performance of Different Cotton and Nylon Swabs on DNA Recovery and Storage

Touch DNA samples are routine yet challenging pieces of evidence that provide investigators with information that helps them solve crimes. However, this type of evidence can be easily lost if the correct collection method is not used. This problem could be overcome with an optimal method of collection that increases the amount of touch DNA collected from different types of surfaces. Better-quality touch DNA can increase the chances of getting a full genetic profile. This study was divided into two parts which aimed to assess whether the type of swab used on different surfaces will significantly increase DNA recovery, concentrations, and the DNA preservation during three different timeframes (24h, 1 month and 3 months). Two different cotton swabs and Nylon swabs were used to lift touch DNA on three different surfaces (glass, plastic and wood) to identify the most suitable method of collection across all three surfaces. A total of 72 samples were lifted (3 replicates from each swab on 3 different surfaces) from two different participants (Male and Female) which were left to dry for 14 days in room temperature prior to DNA extraction. DNA preservation of the swabs was observed while using three dilutions of blood sample which was prepared from one of the volunteers (1:1 – 1:10 – 1:20) where 10 uL of each dilution was pipetted onto the four types of swabs in three replicates (n=36) to observe the preservation over three different timeframes 24h storage, 1 Month and 3 Months with a total of 108 samples. The COPAN CLASSIQSwabsTM Dry swab showed an overall average result during the storage periods of 24h with (1:1) dilution by (2.694ng/μL), (1:10) dilution with (0.548ng/μL) and (1:20) dilution with (0.143ng/μL). Results for the period of 1 Month also showed an average of (1:1) dilution with (2.825ng/μL), (1:10) dilution with (0.361ng/μL) and (1:20) dilution with (0.156ng/μL). These findings can be helpful for laboratories and crime scene investigators to optimize DNA sample collection and preservation based on their workflow

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

•We report INICC device-associated module data of 50 countries from 2010-2015.•We collected prospective data from 861,284 patients in 703 ICUs for 3,506,562 days.•DA-HAI rates and bacterial resistance were higher in the INICC ICUs than in CDC-NHSN's.•Device utilization ratio in the INICC ICUs was similar to CDC-NHSN's. Background: We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific. Methods: During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days. Results: Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs. Conclusions: Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically