Streaking Urine Culture Devices
The principal disadvantage of conventional dipslide is its inability to isolate the separate colonies at even low concentrations of bacteria in urine, having often caused the undifferentiated pattern of confluent growth on agar surfaces, making the detection and isolation of urinary pathogens particularly difficult when two or more colonies are present. It has known that all clinically significant cases of UTI are usually accompanied with the high level of bacteriuria, so this disadvantage of conventional dipslide reduces the economical efficiency of the method since each such case requires the additional isolating procedures and correspondingly, the additional time, reagents and labour. The results of our study show, that the confluent growth of bacteria is observed on the agar surfaces of dipslide even in concentration of 105 CFU/ml that is admitted as diagnostic cut-off of UTI.
DipStreakTM/Diaslide® (Novamed Ltd, Israel) is a new, patented urine culture device that combines dipslide technology and a unique streaking inoculation mechanism, allowing the bacterial counting, excellent colony isolation and presumptive identification of the species. This device can be easily inoculated at the collection site and then sent to the laboratory, thus decreasing bacterial overgrowth.
Because of unique streaking inoculation mechanism, bacteria growth on the DipStreakTM/Diaslide® in three discrete lines with isolated colonies even from the samples, which were as high as 107 CFU per ml. The lower level of detection of the DipStreakTM/Diaslide® device is between 5x102 and 1x103 CFU/ml performed following the manufacturer's reference chart.
The high ability of DipStreakTM/Diaslide® to separate colonies allows: (1) to detect rapidly the mixed cultures and to save the additional time, reagents and labour in handling of insignificant cases of contamination (more than two pathogens); (2) to shorten the procedures of final identification and susceptibility testing of isolated of pathogen and to save the time, reagents and labour on intermediate isolating procedures.
The use of chromogenic media increases the advantages of DipStreakTM/Diaslide®, allowing for rapid direct or presumptive identification of common bacteria at the species level (E. coli, P. mirabilis, and Enterococcus spp.) or at the group level (Klebsiella-Enterobacter-Serratia-Citrobacter and indole-positive Proteus- Morganella- Providencia) straight away after overnight incubation and only on the basis of colonies colour.
The chromogenic media addition to DipStreakTM/Diaslide® saves more time, reagents and labour on routine bacteriological ID tests and procedures. The results obtained on the primary slide are enough for physician to appoint the preliminary therapy and to increase the chance of patient recovery with all logistic consequences.